Natural viral suppressors of HIV-1 have a unique capacity to maintain γδ T cells

Abstract

Objective: 

To evaluate Vγ2Vδ2 T cells in a group of HIV-infected patients who suppress HIV replication without antiretroviral therapy (natural viral suppressors, NVSs).

Design: 

It is a cross-sectional study.

Methods: 

We compared Vγ2Vδ2 T-cell frequency, T-cell repertoire, and responses to isopentenyl pyrophosphate stimulation between NVSs (n = 21) and HIV-uninfected controls (n = 27) and between NVSs and HIV-infected patients taking HAART with suppressed viral replication (HIV-P; n = 25).

Results: 

NVSs had a mean frequency of 1.06 ± 0.82% CD3⁺Vδ2+ cells among total lymphocytes, which was significantly higher than both control groups (HIV-negative: 0.50 ± 0.53%, P = 0.042; HIV-P: 0.34 ± 0.37%, P = 0.002). The proportion of Vγ2 chains correlating with the Vγ2-Jγ1.2 rearrangement was reduced among NVSs compared with HIV-negative controls (0.57 ± 0.06 vs. 0.32 ± 0.04; P = 0.016) but was increased compared with HIV-P patients (0.32 ± 0.04 vs. 0.22 ± 0.03; P = 0.03). NVSs had a similar baseline frequency of CD27⁻/CD45RA⁻ effector cells (19.6 ± 4.2%) compared with HIV-negative controls (20.8 ± 12.9%; P = 0.35).

Conclusion: 

The altered γδ T-cell receptor repertoire among NVS was consistent with the known effect of HIV-1 on these cells. Uniquely among all HIV-infected groups, NVS reconstituted the γδ T-cell population, eventually reaching levels significantly above controls. This capacity to recover γδ T-cell numbers and function distinguishes individuals who control HIV-1 with and without HAART.