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3D Visualization of Immune Cell Populations in HIV-Infected Tissues via Clearing, Immunostaining, Confocal, and Light Sheet Fluorescence Microscopy

Human Immunodeficiency Virus (HIV), the causative agent of Acquired Immune Deficiency Syndrome (AIDS), is a major global health concern with nearly 40 ...

University of Illinois at Urbana-Champaign

Non-invasive bioluminescent imaging (NIBLI) of HIV-1 infection dynamics allows for real-time monitoring of viral spread and the localization of infected cell populations in living animals. In this report, we describe full-length replication-competent GFP and Nanoluciferase (Nluc) expressing HIV-1 reporter viruses from two clinical transmitted / founder (T/F) strains: TRJO.c and Q23.BG505. By infecting humanized mice with these HIV-1 T/F reporter viruses, we were able to directly monitor longitudinal viral spread at whole-animal resolution via NIBLI at a sensitivity of as few as 30-50 infected cells. Bioluminescent signal strongly correlated with HIV-1 infection and responded proportionally to virus suppression in vivo in animals treated daily with a combination antiretroviral therapy (cART) regimen. Longitudinal NIBLI following cART withdrawal visualized tissue-sites that harbored virus during infection recrudescence. Notably, we observed rebounding infection in the same lymphoid tissues where infection was first observed prior to ART treatment. Our work demonstrates the utility of our system for studying in vivo viral infection dynamics and identifying infected tissue regions for subsequent analyses.

Longitudinal bioluminescent imaging of HIV-1 infection during antiretroviral therapy and treatment interruption in humanized mice.

Small heterodimer partner (SHP) is a crucial regulator of bile acid (BA) transport and synthesis; however, its intestine-specific role is not fully understood. Here, we report that male Intestine-specific Shp Knockout (IShpKO) mice exhibit higher intestinal BA but not hepatic or serum BA levels compared to the f/f Shp animals when challenged with an acute (5-day) 1% cholic acid (CA) diet. We also find that BA synthetic genes Cyp7A1 and Cyp8b1 are not repressed to the same extent in IShpKO compared to control mice post-CA challenge. Loss of intestinal SHP did not alter Fxrα mRNA but increased Asbt (BA ileal uptake transporter) and Ostα (BA ileal efflux transporter) expression even under chow-fed conditions. Surprisingly, the acute CA diet in IShpKO did not elicit the expected induction of Fgf15 but was able to maintain the suppression of Asbt, and Ostα/β mRNA levels. At the protein level, ASBT was downregulated, while OSTα/β expression was induced and maintained regardless of diet. Examination of ileal histology in IShpKO mice challenged with acute CA diet revealed reduced villi length and goblet cell numbers. However, no difference in villi length, and the expression of BA regulator and transporter genes was seen between f/f Shp and IShpKO animals after chronic (14-day) CA diet suggesting a potential adaptive response. We found the upregulation of the Pparα-Ugt axis after 14-days of CA diet may reduce the BA burden and compensate for the ileal SHP function. Thus, our study reveals that ileal SHP expression contributes to both overall intestinal structure and BA homeostasis.

Tongyu Zhang

Department of Microbiology

University of Illinois at Urbana-Champaign

3D Visualization of Immune Cell Populations in HIV-Infected Tissues via Clearing, Immunostaining, Confocal, and Light Sheet Fluorescence Microscopy

Tongyu Zhang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Microbiology

University of Illinois at Urbana-Champaign

3D Visualization of Immune Cell Populations in HIV-Infected Tissues via Clearing, Immunostaining, Confocal, and Light Sheet Fluorescence Microscopy

Department of Microbiology