Increased Frequency of Regulatory T Cells Accompanies Increased Immune Activation in Rectal Mucosae of HIV-Positive Noncontrollers

Abstract

Gut-associated lymphoid tissue (GALT) is a major site of HIV replication and CD4؉ T cell depletion.

Short Communication: HIV+ Viremic Slow Progressors Maintain Low Regulatory T Cell Numbers in Rectal Mucosa but Exhibit High T Cell Activation

“…These individuals were compared to progressors (VL > 10,000, CD4 decline below 500 cells/ll) and controllers (VL < 1,000, infected > 5 years). A previous study from our group reported on mucosal Treg and immune activation in HIV controllers and progressor subjects, who were also used as comparison groups for this study 25 ; however, data and analysis of VSP subjects were not presented in the earlier report. Subjects were recruited at the UC Davis Medical Center, Sacramento, CA or San Francisco General Hospital, UC San Francisco (UCSF).…”

“…Rectal biopsies were obtained by flexible sigmoidoscopy 26 and mucosal leukocytes isolated using collagenase and mechanical disruption. 25 PBMCs and rectal cells were stained with anti-CD3 (clone UCHT1; BD Pharmingen), anti-CD4 (SFCI12T4D11, Beckman Coulter, Brea, CA, or L200, BD Pharmingen), anti-CD8 (SK1 or 3B5, Invitrogen), anti-CD25 (M-A251, BD Pharmingen), anti-CD127 (hIL-7R-M21, BD Pharmingen), anti-CD38 (HIT2, BD Pharmingen), antiprogrammed-death-receptor 1 (PD-1) (eBioJ105, eBioscience), and Live/Dead Fixable Aqua dead cell stain (Invitrogen, Carlsbad, CA), followed by intracellular staining with anti-FOXP3 (PCH101, eBioscience) using the FOXP3 Staining Buffer Set (eBioscience, San Diego, CA). After acquisition on an LSRII flow cytometer (BD Pharmingen), data were analyzed using FlowJo software (Tree-Star Inc., Ashland, OR).…”

“…25,[27][28][29] Although the combination of HLA-DR and CD38 is most commonly used to assess T cell activation in HIV disease, 10 both increased CD38/PD-1 coexpression and reduced CD127 expression have been linked to disease progression. 25 …”

“…Clinical data for controllers and seronegatives have been reported elsewhere. 25 All patient groups were assayed during the same time frame to eliminate potential bias due to reagent or protocol variability.…”

“…25 Briefly, CFSE-stained non-Treg and irradiated, autologous PBMCs were left unstimulated or stimulated with plate-bound anti-CD3 and cultured alone or in the presence of increasing numbers of Treg for 4 days. Cultures were stained with anti-CD3, anti-CD4, anti-CD8, anti-CD25, and anti-FOXP3 and analyzed by flow cytometry.…”