High frequency and proliferation of CD4+FOXP3+ Treg in HIV-1-infected patients with low CD4 counts

✍ Scribed by Xiuqiong Bi; Yasuhiro Suzuki; Hiroyuki Gatanaga; Shinichi Oka

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 224 KB
• Volume: 39
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.200838667

✦ Synopsis

Abstract

The frequency of Treg is reported to be higher in patients with chronic HIV type 1 (HIV‐1) infection and CD45RA^+^ Treg exist in normal adults. In this study, we found a lower absolute number (15 cells/μL) but a higher proportion (16.2%) of FOXP3^+^ cells (Treg) in the CD4^+^ population in treatment‐naïve HIV‐1 patients with low CD4 (<200 cells/μL) counts than in those with high CD4 counts (34 cells/μL and 9.3%) or healthy adults (48 cells/μL and 7.5%). In HIV‐1 patients, CD45RA^+^CCR7^+^, CD45RA^−^CCR7^+^, and CD45RA^−^CCR7^−^ subsets were identified in the Treg population, and the proportion of CD45RA^−^CCR7^−^ Treg was higher (57.9%) in patients with low CD4 than high CD4 counts (38.3%). Treg were in a high proliferation state especially in patients with low CD4 counts. HIV viral load correlated positively with the Treg proliferation rate and the proportion of CD45RA^−^CCR7^−^ Treg. Furthermore, the proliferation of Treg correlated positively with the CD45RA^−^CCR7^−^ Treg proportion but negatively with Treg numbers. Successful antiretroviral therapy resulted in a limited increase in Treg numbers, but their frequency was reduced in 1–2 months due to a rapid rebound of FOXP3^−^ CD4^+^cells. Our results suggest that HIV‐activating Treg may be a reason for the high frequencies of Treg and CD45RA^−^CCR7^−^ Treg in the peripheral blood of late‐stage HIV‐1‐infected patients.