This work was supported in part by research funding from the Elisabeth Glaser Pediatric AIDS Foundation (Pediatric HIV Vaccine Program Award MV-00-9-900-1429-0-00 to MMA), MGH/ECOR (Physician Scientist Development Award to MMA), NIH NIAID (KO8219 AI074405 and AI074405-03S1 to MMA), and the Harvard University Center for AIDS Research (CFAR), an NIH funded program (P30 AI060354) which is supported by the following NIH Co-Funding and Participating Institutes and Centers: NIAID, NCI, NICHD, NHLBI, NIDA, NIMH, NIA, FIC, and OAR. These studies were furthermore supported by the Bill &amp; Melinda Gates Foundation and the Terry and Susan Ragon Foundation.

1. Regulatory T cell isolation from HIV-1 Positive Blood
<ol>
	<li>Carefully transfer blood, collected in ACD tubes, into a 50 ml conical tube for a final volume of 15 ml blood per tube.</li>
	<li>Add 25 &mu;l/ml of blood of RosetteSep Human CD4+ T Cell Enrichment Cocktail, mix carefully and incubate 20 min at room temperature.</li>
	<li>Add 15 ml of PBS/2% FBS to the blood and mix carefully. Layer the diluted blood sample on top of 15 ml of Histopaque at room temperature in a 50 ml conical tube. Spin the conical tube for 20 min at 1,200 x g with a slow start and no brakes.</li>
	<li>Transfer the CD4+ T cell enriched PBMC layer in a new 50 ml conical tube, wash the cells by adding PBS/2% FBS and spin them down for 10 min at 1,200 x g. Then count the cells, wash again and resuspend the cells at about 20 x 106/200 &mu;l.</li>
	<li>Add the following antibodies (concentration): 
	anti-CD3-Phycoerythrin-Cyanine 7 (PE-Cy7) (1/100) 
	anti-CD4-Fluorescein Isothiocyanate (FITC) (1/40) 
	anti-CD25-Allophycocyanin (APC) (1/40) 
	anti-CD127-Phycoerythrin (PE) (1/20) 
	Incubate 30 min in the dark at 4 &deg;C</li>
	<li>Wash the cells with PBS/2% FBS. Resuspend the cells at 20 x 106/ml in PBS/2% FBS and filter them on a 35 &mu;m nylon mesh.</li>
	<li>Using a FACS Aria cell sorter equipped for handling biohazardous material, sort the CD3+CD4+CD25+CD127low Treg in X-VIVO 15 media (see gating strategy in Figure 1). Conventional T cells (CD3+CD4+CD25-CD127+) can be isolated and expanded as negative controls.</li>
</ol>
2. Cell Culture
<ol>
	<li>After isolation, wash the Treg with X-VIVO 15 media.</li>
	<li>Resuspend the cells at 250 x 103/ml in X-VIVO 15 media complemented with 10% Human Serum and Penicillin-Streptomycin (50 U/ml).</li>
	<li>Wash Human T-Activator CD3/CD28 beads according to manufacturer's protocol. Add beads to isolated Tregs at a ratio of 1:1 bead per cell.</li>
	<li>After two days of culture, double the media volume and add IL-2 (300 U/ml).</li>
	<li>Culture the Tregs for 2 weeks. Change media (X-VIVO 15/Human serum/P/S/IL-2) at days 5, 7, 9, 12. Add beads at a 1:1 ratio at day 9. When changing media, keep cells at 250 x 103/ml.</li>
</ol>
3. Phenotyping
At the end of the expansion culture, expanded CD3+CD4+CD25+CD127low Treg can be phenotyped by flow cytometry and compared to expanded CD3+CD4+CD25-CD127+ conventional T cells as a control.
<ol>
	<li>Harvest expanded Tregs/Tconvs and wash them in PBS. Label dead cells using the LIVE/DEAD Fixable Violet Dead Cell Stain Kit according to manufacturer's protocol. Wash the cells in PBS/2% FBS.</li>
	<li>Add the following antibodies (concentration): 
	anti-CD3-PECy7 (1/100) 
	anti-CD4-Qdot-655 (1/200) 
	anti-CD25-PECy5 (1/100) 
	Incubate 30 min in the dark at 4 &deg;C</li>
	<li>Wash the cells and perform the intracellular staining using the Foxp3/ Transcription Factor Staining Buffer Set according to manufacturer's protocol and the following antibodies: 
	anti-FOXP3-PE (1/50) 
	anti-HELIOS-FITC (1/40) 
	anti-CTLA4-APC (1/20) 
	Acquire the data on a flow cytometer.</li>
</ol>
4. Suppression Assay
At the end of the expansion culture, the suppressive function i.e. the capacity of the expanded Treg isolated from HIV-1 positive individuals to suppress the proliferation of activated T cells can be assessed in vitro.
<ol>
	<li>Thaw autologous cryopreserved ex vivo PBMCs. Leave them for about 3 hr in a 37 &deg;C incubator in RPMI 1640 medium containing penicillin/streptomycin, L-glutamine, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer (=R+ media), and 10% FBS (=R10 media).</li>
	<li>Label the dead cells using the LIVE/DEAD Fixable Violet Dead Cell Stain Kit according to the manufacturer's protocol. Wash the cells in PBS/2% FBS.</li>
	<li>Incubate the cells with anti-CD3-PECy7 for 30 min in the dark at 4 &deg;C. Wash the cells with PBS/2% FBS. Resuspend the cells in PBS/2% FBS and filter them on a 35 &mu;m nylon mesh.</li>
	<li>Using a FACS Aria cell sorter equipped for handling biohazardous material, sort the viable CD3+ T cells in R10 media.</li>
	<li>Label the T cells with a cell tracing reagent such as CellTrace Violet or Vybrant CFDA SE Cell Tracer at 5 &mu;M diluted in PBS for 7 min at 37 &deg;C according to the manufacturer's protocol. Resuspend cells in R+ media supplemented with 10% human serum (=hR10 media) at 1 x 106/ml.</li>
	<li>Harvest the expanded Tregs, resuspend the cells at 0.5 x 106/ml in hR10 and prepare dilutions at 0.25 x 106/ml and 0.125 x 106/ml.</li>
	<li>Prepare anti-CD2/anti-CD3/anti-CD28 microbeads according to the manufacturer's protocol, resuspend the microbeads at 0.75 x 106/ml and prepare dilutions at 0.625, 0.562, 0.5 x 106/ml in hR10 media.</li>
	<li>In a 96 wells round bottom plate, transfer cells and beads according to the following plan:</li>
</ol>
<table border="1">
	<tbody>
		<tr>
			<td>T cells:Treg ratio</td>
			<td>1:0</td>
			<td>1:1/2</td>
			<td>1:1/4</td>
			<td>1:1/8</td>
		</tr>
		<tr>
			<td>T cells (50 &mu;l)</td>
			<td>1 x 106/ml</td>
			<td>1 x 106/ml</td>
			<td>1 x 106/ml</td>
			<td>1 x 106/ml</td>
		</tr>
		<tr>
			<td>Tregs (50 &mu;l)</td>
			<td>no</td>
			<td>0.5 x 106/ml</td>
			<td>0.25 x 106/ml</td>
			<td>0.125 x 106/ml</td>
		</tr>
		<tr>
			<td>Beads (100 &mu;l)</td>
			<td>0.5 x 106/ml</td>
			<td>0.75 x 106/ml</td>
			<td>0.625 x 106/ml</td>
			<td>0.562 x 106/ml</td>
		</tr>
		<tr>
			<td>hR10 (50 &mu;l)</td>
			<td>yes</td>
			<td>no</td>
			<td>no</td>
			<td>no</td>
		</tr>
		<tr>
			<td>i.e.</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>T cells</td>
			<td>50 x 103</td>
			<td>50 x 103</td>
			<td>50 x 103</td>
			<td>50 x 103</td>
		</tr>
		<tr>
			<td>Tregs</td>
			<td>0</td>
			<td>25 x 103</td>
			<td>12.5 x 103</td>
			<td>6.25 x 103</td>
		</tr>
		<tr>
			<td>Beads</td>
			<td>50 x 103</td>
			<td>75 x 103</td>
			<td>62.5 x 103</td>
			<td>56.25 x 103</td>
		</tr>
	</tbody>
</table>
<ol start="9">
	<li>After 4 days of culture, wash the cells and incubate them for 30 min at 4 &deg;C with the following antibodies: 
	anti-CD3-PECy7 (1/100) 
	anti-CD4-APC (1/100) 
	anti-CD8-AF700 (1/100)</li>
</ol>
Acquire the data on a flow cytometer. Use the FlowJo proliferation platform to calculate the percentage of divided cells.

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The authors declare that they have no competing financial interests.

Using the protocol described above, Tregs can be successfully isolated and expanded from HIV-1-infected individuals in vitro. Expanded Tregs express high levels of FOXP3, CTLA4 and HELIOS, are highly suppressive and display a highly demethylated Treg-Specific Demethylation Region (TSDR) locus of the FOXP3 gene (data not shown) 15, suggesting true origin from the regulatory T cell lineage, as opposed to activation-induced transient FOXP3 upregulation. Deep sequencing demonstrated that the TCR repertoire of the Tregs is not skewed during the expansion (data not shown).
Regulatory T cells are naturally anergic and need strong stimuli to proliferate; here we used beads coated with anti-CD3 and anti-CD28 16 antibodies in the presence of exogenous IL-2 17. Other groups have successfully used similar methods to expand polyclonal Tregs from healthy donors 18, diabetic patients 19, transplant recipients 20 or antigen-specific Tregs from HCV patients 21 but, to our knowledge, this is the first description of a successful protocol to expand functional Tregs from HIV-1 positive donors.
We chose to use flow-cytometry over immunomagnetic cell sorting in order to isolate the cell population with the best purity possible and to avoid contamination with CD3+CD4+CD25-CD127+ conventional T cells (Tconvs) during expansion. Avoiding contamination with Tconvs is crucial since we found that under the same conditions Tconvs proliferate more rapidly than regulatory T cells, and thus could overgrow Tregs during a prolonged expansion culture. Rapamycin was previously used to inhibit Tconvs growth while favoring expansion and survival of Tregs 22. However rapamycin was found to downregulate CCR5 expression in vitro, an important co-factor of R5 HIV virus entry, which would have made expanded cells less usable to study HIV-1 infection of regulatory T cells by this HIV-1 strain 23.
In the present protocol, Tregs are expanded for 14 days. Although we found expanded Tregs to be still actively suppressive after 21 days, we chose not to prolong our cell culture and preserve the suppressive activity of our cells. Indeed, the group of M. Edinger reported a decrease in FOXP3 when Tregs were expanded more than two weeks and this was associated with moderate Treg suppression 24,25.
Most markers used to characterize regulatory T cells are shared by activated T cells (e.g. FOXP3 26, CTLA4 27). In our hands, even though expanded Tregs expressed higher levels of FOXP3 and CTLA4 compared to expanded conventional T cells (Tconvs), HELIOS was the only marker that was almost exclusively expressed by the expanded Tregs. This protein is mostly expressed by thymic-derived but not by peripherally induced FOXP3+ regulatory T cells 28. Thus, the Tregs isolated and expanded by our protocol could be used to understand the role of thymic-derived Tregs in HIV-immunopathogenesis. The expansion of other Tregs subsets, such as induced antigen-specific Tr1 or Th3 suppressor cells from HIV-1 positive individuals would need alternative adapted protocols 29,30.
In summary, using the described protocol we successfully expanded Tregs from frozen adult and pediatric PBMC as well as GALT (gut associated lymphoid tissue), the major site of HIV-1 replication. Easier access to large numbers of Tregs will help to address important questions concerning their role in HIV-1 immunopathogenesis and to better understandthe role of this T cell subpopulation in HIV-1 immune evasion. We believe that answering these questions may have a strong impact in the development of an effective HIV-1 vaccine and potential new strategies for immunotherapeutic intervention in HIV-1 infection.

HIV / AIDS 전세계 새롭게 2011 년에 감염 추정 2백50만명, 세계 에이즈 전염병을 억제하는 효과적인 HIV 백신에 대한 필요성과 함께 생활 이상의 3400 만 개인과 중요 남아 있습니다. 그러나 강렬한 연구 노력의 년간에도 불구하고, 현재까지 HIV-1 백신 효능 시험은 겸손 보호를 1-3로 이어질 및 보호 면역의 상관 관계를 제대로 이해 남아 있습니다. 보호에 필요한 면역 반응의 특성을 해명하는 것은 효과적인 HIV-1 백신과 HIV-1 감염을 대상으로 다른 immunotherapeutic 전략의 전략적 설계를위한 필수적입니다. 자연적인 CD4 + 조절 T 세포 (Tregs의)는 따라서 면역 - 매개 조직의 손상을 제한, 과도한 면역 활성을 조절하여 면역 세포의 항상성 유지에 중요하다. 그러나, 그들은 또한 병원균에 대한 면역 반응을 억제하고 자신의 통관을 방지 할 수 있습니다. 암과 헤파titis B 백신 연구는 Tregs의의 활동을 감소하는 백신 반응과 바이러스에 4-7에 대한 항원 특이 면역을 향상시킬 수 있음을 증명하고있다. 그러나 HIV-1 감염의 맥락에서, 규제 T 세포의 정확한 영향은 불완전하게 이해 남아있다. Tregs의이 활성화 된 T 세포 8 바이러스 복제를 감소 그리고 아마도 면역 활성화 9 영향을 표시했다. 그들은 또한 질병의 진행 10,11에 대한 부정적인 결과가있을 수 HIV-1 특이 면역 반응을 억제하기 위해 표시되었습니다. 따라서, HIV-1 백신의 효능을 강화하는 Treg 활동을 조절 할 수되기 전에,이 질병의 맥락에서 그들의 기능에 추가 통찰력을 얻을 것이 중요합니다. 인간 CD4 + 조절 T 세포는 약 5 CD4의 % + 말초 혈액에서 T 세포, 그리고 추가로 절대 숫자 HIV-관련 CD4 + T 세포 고갈 12와 감소를 나타내는 상대적으로 부족한 세포 인구입니다 &lt;/&gt;을 먹다. 공동 문화를 Treg와 같은 T 세포 증식 분석으로 Treg 기능을 평가하는 현재의 분석은 비교적 큰 세포 수에게 12을 사용합니다. 따라서 진보와 개인에 규제 T 세포의 기능과 특이성을 특성화 HIV-1 질병은 HIV 병인에 대한 자신의 중요성에도 불구하고, 도전하고있다. HIV-1 환자에서 Tregs의의 생체 분리 및 확장은 이러한 제한을 극복 할 수있는 솔루션을 나타낼 수 있습니다. 여기에서 우리는 체외에서 HIV-1에 감염된 사람에서 파생 된 기능 Tregs의 검색을 확장 할 수있는 쉽고 강력한 프로토콜을 설명합니다, 우리는 더 이상 어떻게 표현형을 해석하고 유세포 분석을 사용하여 억제 기능을 테스트합니다. 우리는이 프로토콜은 Tregs의 접근을 용이하게하고 HIV-1 질병의 진행에서 자신의 역할을 이해하는 데 도움이됩니다 믿습니다.

<table border="1">
	<tbody>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Reagents</td>
		</tr>
		<tr>
			<td>RosetteSep Human CD4+ T Cell Enrichment Cocktail</td>
			<td>Stemcells technologies</td>
			<td>15062</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Sigma</td>
			<td>D8537</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Sigma</td>
			<td>F4135</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Histopaque</td>
			<td>Sigma</td>
			<td>H8889</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD3-PECy7</td>
			<td>BD Pharmingen</td>
			<td>557851</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD4-FITC</td>
			<td>eBioscience</td>
			<td>11-0049-42</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD25-APC</td>
			<td>eBioscience</td>
			<td>17-0259-42</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD127-PE</td>
			<td>BD Pharmingen</td>
			<td>557938</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Round-Bottom tube with 35 &mu;m a nylon mesh</td>
			<td>BD Falcon</td>
			<td>352235</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>X-VIVO 15</td>
			<td>Lonza</td>
			<td>04-418Q</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>Mediatech</td>
			<td>30-001-Cl</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Human Serum</td>
			<td>Gemini Bio-Products</td>
			<td>100-512</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Human T-activator CD3/CD28</td>
			<td>Life Technologies</td>
			<td>111.31D</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>IL-2</td>
			<td>NIH Aids Research &amp; Reference Reagent Program</td>
			<td>136</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>LIVE/DEAD Fixable Violet Dead Cell Stain Kit</td>
			<td>Life technologies</td>
			<td>L34955</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD4-qdot-655</td>
			<td>Life Technologies</td>
			<td>Q10007</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD25-PECy5</td>
			<td>eBiosciences</td>
			<td>15-0259-42</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Foxp3 / Transcription Factor Staining Buffer Set</td>
			<td>eBiosciences</td>
			<td>00-5523-00</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-FOXP3-PE</td>
			<td>eBiosciences</td>
			<td>12-4776-42</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-HELIOS-FITC</td>
			<td>Biolegend</td>
			<td>137204</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CTLA4-APC</td>
			<td>BD Pharmingen</td>
			<td>555855</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>CellTrace Violet Cell Proliferation Kit</td>
			<td>Life Technologies</td>
			<td>C34557</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Vybrant CFDA SE Cell Tracer Kit</td>
			<td>Life Technologies</td>
			<td>V12883</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Mediatech</td>
			<td>25-060-Cl</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Treg Suppression inspector</td>
			<td>Miltenyi Biotec</td>
			<td>130-092-909</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD4-APC</td>
			<td>BD Pharmingen</td>
			<td>340443</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD8-AF700</td>
			<td>BD Pharmingen</td>
			<td>557945</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Sigma</td>
			<td>R0883</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Glutamine</td>
			<td>Mediatech</td>
			<td>25-002-Cl</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Materials</td>
		</tr>
		<tr>
			<td>BD Vacutainer Blood Collection Tube w/ ACID CITRATE DEXTROSE (ACD)</td>
			<td>Becton, Dickinson and Company (BD)</td>
			<td>364606</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FACSAria IIu Cell Sorter</td>
			<td>BD Biosciences</td>
			<td>-</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>LSR II Flow Cytometer</td>
			<td>BD Biosciences</td>
			<td>-</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FlowJo</td>
			<td>Tree Star</td>
			<td>v887</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

new tools to expand regulatory t cells from hiv-1-infected individuals

CD4 + 조절 T 세포 (Tregs의)는 강력한 면역 변조기이며, 인간의 면역 항상성에 중요한 기능을 제공합니다. Tregs의 고갈은 암과 전염성 병원균에 대한 백신 설정에서 항원 특이 T 세포 반응의 측정이 증가하게되었다. 그들은 하나 해로운 HIV-1과 연관된 면역 활성을 억제하는 역할을하기 때문에 HIV-1 질병의 진행을 느리게하거나 또는 HIV-1 특이 면역을 억제함으로써 바이러스를 촉진 할 수 그러나, HIV-1 면역 기전에서의 역할은 논란이 남아있다 확산. 이해와 HIV-1의 맥락에서 변조 Treg 기능은 면역 또는 HIV 백신에 대한 잠재적 인 새로운 전략으로 이어질 수 있습니다. 그러나 중요한 질문을주의 깊게 연구 할 필요가 HIV-1 감염의 맥락에서 자신의 역할에 남아 있습니다. Treg 인구 공부, 인간 CD4 + 말초 혈액에서 T 세포의 약 5 %를 대표하는 에스 어려운 것으로 입증되었습니다pecially HIV-1 관련 CD4의 T 세포 HIV-1에 감염된 사람들과 함께하는 Treg 고갈이 발생합니다. 고급 HIV-1 질병이나 조직 샘플은 단지 매우 작은 생물 학적 샘플을 얻을 수있는, 그러므로 매우 어려운과 개인의 규제 T 세포의 특성. 우리는 HIV-1 양성 개인의 Tregs의의 분리 및 확장을 사용하여 이러한 한계를 극복 할 수있는 기술적 인 해결책을 제안한다. 여기에서 우리는 성공적으로 체외에서 HIV-1에 감염된 개인으로부터 Tregs의 격리를 확장 할 수있는 쉽고 강력한 방법을 설명합니다. 흐름 분류 CD3 + CD4 + CD25 + CD127 낮은 Tregs의이 anti-CD3/anti-CD28 코팅 구슬로 자극하고 IL-2의 면전에서 배양 하였다. 확장 Tregs의이 FOXP3 높은 수준의 CTLA4를 표현 HELIOS 기존의 T 세포에 비해 매우 억압적인 것으로 보였다. Tregs의 큰 숫자에 쉽게 접근 연구자가 난을 해결하기 위해 수HIV-1 immunopathogenesis에서 자신의 역할에 관한 mportant 질문입니다. 우리는이 질문에 대답하는 것은 효과적인 HIV-1 백신의 개발에 유용한 통찰력을 제공 할 수 있습니다 믿습니다.

The expression of interleukin 2 receptor (CD25) and the interleukin 7 receptor (CD127) have been described as reliable surface markers to identify functional Treg populations 13 and have been shown to correlate with CD4+CD25+FOXP3+ Tregs 9,12. Figure 1 represents the gating strategy used to flow-sort single CD3+CD4+CD25+CD127low Tregs from PBMC isolated from an HIV-1-positive individual. The CD25/CD127 antibody clones and their conjugate are crucial to reach a good separation of the Treg population; we found the CD25 APC (eBioscience)/ CD127 PE (BD Pharmingen) combination to work well in our hands.
In a representative example (Figure 2), the Treg expansion fold change reached 765 after 14 days of culture. The expansion fold change can vary from one individual to another and can be as low as ca. 100 or reach ca. 2500. The human serum lot used in the media can also impact the expansion fold change; it is suggested to screen different lots of human serum to achieve optimal expansion capacity.
Examples of histograms staining for selected markers of Tregs (CTLA4, FOXP3 and HELIOS) are represented in Figure 3. Since most of the Treg markers are also expressed by activated conventional T cells, displaying the mean fluorescence intensity (MFI) may be more informative than the frequency of the positive population in this context.
A fundamental characteristic of regulatory T cells is their capacity to suppress cellular immune responses. Using a standardized flow-based T cell proliferation assay (Figure 4) expanded Tregs can suppress the proliferation of activated autologous T cells. Proliferation of T cells are assayed by a membrane-permeant reactive tracer (CellTrace Violet) after 4 days of co-culture with different anti-CD2/anti-CD3/antiCD28 microbeads activated T cells to Tregs ratios. The numbers of divided cells were calculated using the FlowJo Proliferation platform. CD2 stimulation was shown to up-regulate FOXP3 expression and lead to enhanced Treg function 14. In our hands the use of microbeads gives a stronger and more consistent proliferation than plate-bound anti-CD3 with or without the addition of anti-CD28. For the suppression assay, media is complemented with human serum, we suggest to screen different serum lots to achieve optimal and constant suppressive capacity.
<img alt="Figure 1" fo:content-width="5.5in" fo:src="/files/ftp_upload/50244/50244fig1highres.jpg" src="/files/ftp_upload/50244/50244fig1.jpg" /> 
 Figure 1. Flow cytometry gating strategy to sort singles CD3+CD4+CD25+CD127low Tregs from PBMC isolated from an HIV-1-positive individual. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50244/50244fig1large.jpg" target="_blank">Click here to view larger figure</a>.
<img alt="Figure 2" fo:content-width="1.5in" fo:src="/files/ftp_upload/50244/50244fig2highres.jpg" src="/files/ftp_upload/50244/50244fig2.jpg" /> 
 Figure 2. Representative example of the expansion fold change of Tregs isolated from an HIV-1-infected individual cultured during 14 days.
<img alt="Figure 3" fo:content-width="5in" fo:src="/files/ftp_upload/50244/50244fig3highres.jpg" src="/files/ftp_upload/50244/50244fig3.jpg" /> 
 Figure 3. Examples of flow cytometry histograms staining of expanded Tregs isolated from an HIV-1-infected Treg using different Tregs markers. Expanded Tregs are figured in grey and expanded Tconvs in white. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50244/50244fig3large.jpg" target="_blank"> Click here to view larger figure</a>.
<img alt="Figure 4" fo:content-width="5in" fo:src="/files/ftp_upload/50244/50244fig4highres.jpg" src="/files/ftp_upload/50244/50244fig4.jpg" /> 
 Figure 4. Example of flow-based T cell proliferation assay using a membrane-permeant reactive tracer and activated T cells at different responder T cell to Treg ratios. CD4+ T cells are figured in grey and CD8+ T cells in black. The numbers of divided cells are figured in the histograms.

Watch this Scientific Journal Video about New Tools to Expand Regulatory T Cells from HIV-1-infected Individuals at JoVE.com

New Tools to Expand Regulatory T Cells from HIV-1-infected Individuals

CD4+ Regulatory T cells are potent immune-modulators and serve important functions in immune homeostasis. The paucity of these cells in peripheral blood makes functional studies challenging, specifically in the context of HIV-1-infection. We here describe a method to isolate and expand functional CD4+ Tregs from peripheral blood from HIV-1-infected individuals.

새로운 도구는 HIV-1에 감염된 개인으로부터 규제 T 세포를 확장하려면

CD4+ Regulatory T cells (Tregs) are potent immune modulators and serve an important function in human immune homeostasis. Depletion of Tregs has led to ...

new-tools-to-expand-regulatory-t-cells-from-hiv-1-infected-individuals

Nanyang Technological University

Research

JoVE Journal

Immunology and Infection

11.1K 조회수.  Ragon Institute of MGH, MIT, and Harvard. CD4+ Regulatory T cells are potent immune-modulators and serve important functions in immune homeostasis. The paucity of these cells in peripheral blood makes functional studies challenging, specifically in the context of HIV-1-infection. We here describe a method to isolate and expand functional CD4+ Tregs from peripheral blood from HIV-1-infected individuals.

비디오: New Tools to Expand Regulatory T Cells from HIV-1-infected Individuals

Retroviral Transduction of T-cell Receptors in Mouse T-cells

T-cell receptors (TCRs) play a central role in the immune system. TCRs on T-cell surfaces can specifically recognize peptide antigens presented by antigen presenting cells (APCs)1. This recognition leads to the activation of T-cells and a series of functional outcomes (e.g. cytokine production, killing of the target cells). Understanding the functional role of TCRs is critical to harness the power of the immune system to treat a variety of immunology related diseases (e.g. cancer or autoimmunity).
It is convenient to study TCRs in mouse models, which can be accomplished in several ways. Making TCR transgenic mouse models is costly and time-consuming and currently there are only a limited number of them available2-4. Alternatively, mice with antigen-specific T-cells can be generated by bone marrow chimera. This method also takes several weeks and requires expertise5. Retroviral transduction of TCRs into in vitro activated mouse T-cells is a quick and relatively easy method to obtain T-cells of desired peptide-MHC specificity. Antigen-specific T-cells can be generated in one week and used in any downstream applications. Studying transduced T-cells also has direct application to human immunotherapy, as adoptive transfer of human T-cells transduced with antigen-specific TCRs is an emerging strategy for cancer treatment6.
Here we present a protocol to retrovirally transduce TCRs into in vitro activated mouse T-cells. Both human and mouse TCR genes can be used. Retroviruses carrying specific TCR genes are generated and used to infect mouse T-cells activated with anti-CD3 and anti-CD28 antibodies. After in vitro expansion, transduced T-cells are analyzed by flow cytometry.

We present a protocol to produce antigen-specific mouse T-cells using retroviral transduction

마우스 T - 세포에서 T - 세포 수용체의 Retroviral 전달

T-cell receptors (TCRs) play a central role in the immune system. TCRs on T-cell surfaces can specifically recognize peptide antigens presented by antigen ...

연구

면역학 및 감염병학

Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays

Natural killer (NK) cells are a vital component of the innate immune response to virus-infected cells. It is important to understand the ability of NK cells to recognize and lyse HIV-1 infected cells because identifying any aberrancy in NK cell function against HIV-infected cells could potentially lead to therapies that would enhance their cytolytic activity. There is a need to use HIV-infected primary T-cell blasts as target cells rather then infected-T-cell lines in the cytotoxicity assays. T-cell lines, even without infection, are quite susceptible to NK cell lysis. Furthermore, it is necessary to use autologous primary cells to prevent major histocompatibility complex class I mismatches between the target and effector cell that will result in lysis. Early studies evaluating NK cell cytolytic responses to primary HIV-infected cells failed to show significant killing of the infected cells 1,2. However, using HIV-1 infected primary T-cells as target cells in NK cell functional assays has been difficult due the presence of contaminating uninfected cells 3. This inconsistent infected cell to uninfected cell ratio will result in variation in NK cell killing between samples that may not be due to variability in donor NK cell function. Thus, it would be beneficial to work with a purified infected cell population in order to standardize the effector to target cell ratios between experiments 3,4. Here we demonstrate the isolation of a highly purified population of HIV-1 infected cells by taking advantage of HIV-1's ability to down-modulate CD4 on infected cells and the availability of commercial kits to remove dead or dying cells 3-6. The purified infected primary T-cell blasts can then be used as targets in either a degranulation or cytotoxic assay with purified NK cells as the effector population 5-7. Use of NK cells as effectors in a degranulation assay evaluates the ability of an NK cell to release the lytic contents of specialized lysosomes 8 called "cytolytic granules". By staining with a fluorochrome conjugated antibody against CD107a, a lysosomal membrane protein that becomes expressed on the NK cell surface when the cytolytic granules fuse to the plasma membrane, we can determine what percentage of NK cells degranulate in response to target cell recognition. Alternatively, NK cell lytic activity can be evaluated in a cytotoxic assay that allows for the determination of the percentage of target cells lysed by release of 51Cr from within the target cell in the presence of NK cells.

Cytotoxicity assays to measure natural killer cell lytic responses to HIV-infected cells is limited by the purity of the target cells. We demonstrate here the isolation of a highly purified population of HIV-1 infected primary T-cell blasts by taking advantage of HIV-1 s ability to down-modulate CD4.

준비 및 사용 HIV - 1 차 감염된 CD4 + 대상 세포로 T 세포 자연 킬러 세포 세포 독성 Assays에서

 Natural killer (NK) cells are a vital component of the innate immune response to virus-infected cells. It is important to understand the ability of NK ...

Generation of Induced Regulatory T Cells from Primary Human Na&iuml;ve and Memory T Cells

The development and maintenance of immunosuppressive CD4+ regulatory T cells (Tregs) contribute to the peripheral tolerance needed to remain in immunologic homeostasis with the vast amount of self and commensal antigens in and on the human body. Perturbations in the balance between Tregs and inflammatory conventional T cells can result in immunopathology or cancer. Although therapeutic injection of Tregs has been shown to be efficacious in murine models of colitis1 , type I diabetes2 , rheumatoid arthritis and graft versus host disease,4 several fundamental differences in human versus mouse Treg biology5 has thus far precluded clinical use. The lack of sufficient number, purity, stability and homing specificity of therapeutic Tregs necessitated a dynamic platform of human Treg development on which to optimize conditions for their ex vivo expansion6.
Here we describe a method for the differentiation of induced Tregs (iTregs) from a single human peripheral blood donor which can be broken down into four stages: isolation of peripheral blood mononuclear cells, magnetic selection of CD4+ T cells, in vitro cell culture and fluorescence activated cell sorting (FACS) of T cell subsets. Since the Treg signature transcription factor forkhead box P3 (FoxP3) is an activation-induced transcription factor in humans7 and no other unique marker exists, a combinatorial panel of markers must be used to identify T cells with suppressor activity. After six days in culture, cells in our system can be demarcated into na&iuml;ve T cells, memory T cells or iTregs based on their relative expression of CD25 and CD45RA. As memory and na&iuml;ve T cells have different reported polarization requirements and plasticities8 , pre-sorting of the initial T cell population into CD45RA+ and CD45RO+ subsets can be used to examine these discrepancies. Consistent with others, our CD25HiCD45RA- iTregs express high levels of FoxP39 , GITR and CTLA-411 and low levels of CD12712 . Following FACS of each population, resultant cells can be used in a suppressor assay which evaluates the relative ability to retard the proliferation of carboxyfluorescein succinimidyl ester (CFSE)-labeled autologous T cells.

Generation of Induced Regulatory T Cells from Primary Human Na&#239;ve and Memory T Cells

We describe a method for generating regulatory, memory and na&#239;ve T cells from a single human blood donor. Polarized Tregs can be then compared to other subsets in a variety of genetic and functional applications with genetic homogeneity, including a suppression assay also detailed here.

기본 인적 나이브 및 메모리 T의 세포로부터 유도된 규제 T 세포의 생성

The development and maintenance of immunosuppressive CD4+ regulatory T cells (Tregs) contribute to the peripheral tolerance needed to remain in ...

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the protocols described here use freshly isolated human peripheral blood mononuclear cells (PBMCs) or plasmacytoid dendritic cells (pDCs) to sense infections in either T cell line (MT4) or heterologous primary CD4+ T cells. In order to ensure proper sensing, it is essential that PBMC are isolated immediately after blood collection and that optimal percentage of infected T cells are used. Furthermore, multi-parametric flow cytometric staining can be used to confirm that PBMC samples contain the different cell lineages at physiological ratios. A number of controls can also be included to evaluate viability and functionality of pDCs. These include, the presence of specific surface markers, assessing cellular responses to known agonist of Toll-Like Receptors (TLR) pathways, and confirming a lack of spontaneous type-I interferon (IFN) production. In this system, freshly isolated PBMCs or pDCs are co-cultured with HIV-1 infected cells in 96 well plates for 18-22 hr. Supernatants from these co-cultures are then used to determine the levels of bioactive type-I IFNs by monitoring the activation of the ISGF3 pathway in HEK-Blue IFN-&#945;/&#946; cells. Prior and during co-culture conditions, target cells can be subjected to flow cytometric analysis to determine a number of parameters, including the percentage of infected cells, levels of specific surface markers, and differential killing of infected cells. Although, these protocols were initially developed to follow type-I IFN production, they could potentially be used to study other imuno-modulatory molecules released from pDCs and to gain further insight into the molecular mechanisms governing HIV-1 innate sensing.

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

Unlike cell-free HIV-1 particles, infected CD4+ T cells are effectively sensed by plasmacytoid dendritic cells (pDCs). This manuscript describes a method where peripheral blood mononuclear cells (PBMCs) or isolated pDCs are co-cultured with HIV-1 infected T cells to evaluate innate sensing by pDCs as assessed by release of type-I IFN.

HIV-1 감염 CD4의 타고난 감지 평가<sup&gt; +</sup&gt;를 사용하여 형질 수지상 세포에 의한 T 세포<em&gt; 예 생체 내</em&gt; 공동 문화 시스템.

HIV-1 innate sensing requires direct contact of infected CD4+ T cells with plasmacytoid dendritic cells (pDCs). In order to study this process, the ...

Derivation of T Cells In Vitro from Mouse Embryonic Stem Cells

The OP9/OP9-DL1 co-culture system has become a well-established method for deriving differentiated blood cell types from embryonic and hematopoietic progenitors of both mouse and human origin. It is now used to address a growing variety of complex genetic, cellular and molecular questions related to hematopoiesis, and is at the cutting edge of efforts to translate these basic findings to therapeutic applications. The procedures are straightforward and routinely yield robust results. However, achieving successful hematopoietic differentiation in vitro requires special attention to the details of reagent and cell culture maintenance. Furthermore, the protocol features technique sensitive steps that, while not difficult, take care and practice to master. Here we focus on the procedures for differentiation of T lymphocytes from mouse embryonic stem cells (mESC). We provide a detailed protocol with discussions of the critical steps and parameters that enable reproducibly robust cellular differentiation in vitro. It is in the interest of the field to consider wider adoption of this technology, as it has the potential to reduce animal use, lower the cost and shorten the timelines of both basic and translational experimentation.

Derivation of T Cells In Vitro from Mouse Embryonic Stem Cells

Mouse embryonic stem cells can be differentiated to T cells in vitro using the OP9-DL1 co-culture system. Success in this procedure requires careful attention to reagent/cell maintenance, and key technique sensitive steps. Here we discuss these critical parameters and provide a detailed protocol to encourage adoption of this technology.

T 세포의 유도<em&gt; 체외</em&gt; 마우스 배아 줄기 세포에서

The OP9/OP9-DL1 co-culture system has become a well-established method for deriving differentiated blood cell types from embryonic and hematopoietic ...

T Cells Capture Bacteria by Transinfection from Dendritic Cells

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic cells (DCs) by a process called transinfection. Here, we describe the analysis of the transinfection process, which occurs during the course of antigen presentation. This process was unveiled by using CD4+ T cells from transgenic OTII mice, which bear a T cell receptor (TCR) specific for a peptide of ovoalbumin (OVAp), which therefore can form stable immune complexes with infected dendritic cells loaded with this specific OVAp. The dynamics of green fluorescent protein (GFP)-expressing bacteria during DC-T cell transmission can be monitored by live-cell imaging and the quantification of bacterial transinfection can be performed by flow cytometry. In addition, transinfection can be quantified by a more sensitive method based in the use of gentamicin, a non-permeable aminoglycoside antibiotic killing extracellular bacteria but not intracellular ones. This classical method has been used previously in microbiology to study the efficiency of bacterial infections. We hereby explain the protocol of the complete process, from the isolation of the primary cells to the quantification of transinfection.

Here a protocol is presented to measure bacterial capture by CD4+ T cells which occurs during antigen presentation via transinfection from pre-infected dendritic cells (DC). We show how to perform the necessary steps: isolation of primary cells, infection of DC, DC/T cell conjugate formation, and measurement of bacterial T cell transfection.

T 세포는 수지상 세포에서 Transinfection에 의해 박테리아를 캡처

Recently, we have shown, contrary to what is described, that CD4+ T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic ...

Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice

Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4+ T cells. Treg cells play crucial roles in immune tolerance and homeostasis maintenance by regulating the immune response. The primary role of Treg cells is to suppress the proliferation of effector T (Teff) cells and the production of cytokines such as IFN-&#947;, TNF-&#945;, and IL-2. It has been demonstrated that Treg cells&#39; ability to inhibit the function of Teff cells is enhanced during persistent pathogen infection and cancer development. To clarify the function of Treg cells under resting or inflamed conditions, a variety of in vitro suppression assays using mouse or human Treg cells have been devised. The main aim of this study is to develop a method to compare the differences in phenotype and suppressive function between resting and activated Treg cells. To isolate activated Treg cells, mice were infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13), a chronic strain of LCMV. Treg cells isolated from the spleen of LCMV CL13-infected mice exhibited both the activated phenotype and enhanced suppressive activity compared with resting Treg cells isolated from na&#239;ve mice. Here, we describe the basic protocol for ex vivo phenotype analysis to distinguish activated Treg cells from resting Treg cells. Furthermore, we describe a protocol for the measurement of the suppressive activity of fully activated Treg cells.

Here, we describe a protocol to analyze the phenotype of regulatory T (Treg) cells isolated from na&#239;ve and chronic lymphocytic choriomeningitis virus-infected mice. In addition, we provide a process to evaluate the suppressive activity of the Treg cells.

표현형 및 만성 림프 구성 맥락 수막염 바이러스에 감염된 마우스에서 고립 활성화 규제 T 세포의 기능 분석

Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4+ T cells. Treg cells play crucial roles in immune tolerance ...

Development of Stem Cell-derived Antigen-specific Regulatory T Cells Against Autoimmunity

Autoimmune diseases arise due to the loss of immunological self-tolerance. Regulatory T cells (Tregs) are important mediators of immunologic self-tolerance. Tregs represent about 5 - 10% of the mature CD4+ T cell subpopulation in mice and humans, with about 1 - 2% of those Tregs circulating in the peripheral blood. Induced pluripotent stem cells (iPSCs) can be differentiated into functional Tregs, which have a potential to be used for cell-based therapies of autoimmune diseases. Here, we present a method to develop antigen (Ag)-specific Tregs from iPSCs (i.e., iPSC-Tregs). The method is based on incorporating the transcription factor FoxP3 and an Ag-specific T cell receptor (TCR) into iPSCs and then differentiating on OP9 stromal cells expressing Notch ligands delta-like (DL) 1 and DL4. Following in vitro differentiation, the iPSC-Tregs express CD4, CD8, CD3, CD25, FoxP3, and Ag-specific TCR and are able to respond to Ag stimulation. This method has been successfully applied to cell-based therapy of autoimmune arthritis in a murine model. Adoptive transfer of these Ag-specific iPSC-Tregs into Ag-induced arthritis (AIA)-bearing mice has the ability to reduce joint inflammation and swelling and to prevent bone loss.

We present here a method to develop functional antigen (Ag)-specific regulatory T cells (Tregs) from induced pluripotent stem cells (iPSCs) for immunotherapy of autoimmune arthritis in a murine model.

자가 면역 대해 줄기 세포 유래의 항원 특이 적 조절 T 세포의 발달

Autoimmune diseases arise due to the loss of immunological self-tolerance. Regulatory T cells (Tregs) are important mediators of immunologic ...

SILAC Based Proteomic Characterization of Exosomes from HIV-1 Infected Cells

Proteomics is the large-scale analysis of proteins. Proteomic techniques, such as liquid chromatography tandem mass spectroscopy (LC-MS/MS), can characterize thousands of proteins at a time. These powerful techniques allow us to have a systemic understanding of cellular changes, especially when cells are subjected to various stimuli, such as infections, stresses, and specific test conditions. Even with recent developments, analyzing the exosomal proteome is time-consuming and often involves complex methodologies. In addition, the resultant large dataset often needs robust and streamlined analysis in order for researchers to perform further downstream studies. Here, we describe a SILAC-based protocol for characterizing the exosomal proteome when cells are infected with HIV-1. The method is based on simple isotope labeling, isolation of exosomes from differentially labeled cells, and mass spectrometry analysis. This is followed by detailed data mining and bioinformatics analysis of the proteomic hits. The resultant datasets and candidates are easy to understand and often offer a wealth of information that is useful for downstream analysis. This protocol is applicable to other subcellular compartments and a wide range of test conditions.

Here, we describe a quantitative proteomics method using the technique of stable isotope labeling by amino acids in cell culture (SILAC) to analyze the effects of HIV-1 infection on host exosomal proteomes. This protocol can be easily adapted to cells under different stress or infection conditions.

HIV-1에 감염된 세포에서 엑소 좀의 SILAC 기반 단백체 특성

Proteomics is the large-scale analysis of proteins. Proteomic techniques, such as liquid chromatography tandem mass spectroscopy (LC-MS/MS), can ...

In Vitro Differentiation of Human CD4+FOXP3+ Induced Regulatory T Cells (iTregs) from Na&#239;ve CD4+ T Cells Using a TGF-&#946;-containing Protocol

Regulatory T cells (Tregs) are an integral part of peripheral tolerance, suppressing immune reactions against self-structures and thus preventing autoimmune diseases. Clinical approaches to adoptively transfer Tregs, or to deplete Tregs in cancer, are underway with promising first outcomes. 
Because the number of naturally occurring Tregs (nTregs) is very limited, studying certain Treg features using in vitro induced Tregs (iTregs) can be advantageous. To date, the best although not absolutely specific protein marker to delineate Tregs is the transcription factor FOXP3. Despite the importance of Tregs including non-redundant roles of peripherally induced Tregs, the protocols to generate iTregs are currently controversial, particularly for human cells. This protocol therefore describes the in vitro differentiation of human CD4+FOXP3+ iTregs from human na&#239;ve T cells using a range of Treg-inducing factors (TGF-&#946; plus IL-2 only, or their combination with retinoic acid, rapamycin or butyrate) in parallel. It also describes the phenotyping of these cells by flow cytometry and qRT-PCR. 
These protocols result in reproducible expression of FOXP3 and other Treg signature genes and enable the study of general FOXP3-regulatory mechanisms as well as protocol-specific effects to delineate the impact of certain factors. iTregs can be utilized to study various phenotypic aspects as well as molecular mechanisms of Treg induction. Detailed molecular studies are facilitated by relatively large cell numbers that can be obtained. 
A limitation for the application of iTregs is the relative instability of FOXP3 expression in these cells compared to nTregs. iTregs generated by these protocols can also be used for functional assays such as studying their suppressive function, in which iTregs induced by TGF-&#946; plus retinoic acid and rapamycin display superior suppressive activity. However, the suppressive capacity of iTregs can differ from nTregs and the use of appropriate controls is crucial.

This protocol describes the reproducible generation and phenotyping of human induced regulatory T cells (iTregs) from na&#239;ve CD4+ T cells in vitro. Different protocols for FOXP3 induction allow for the study of specific iTreg phenotypes obtained with respective protocols.