IL-17 expression in ex vivo γδ T cells from HIV-1–infected patients and response to microbial antigens. PBMCs from HIV-1–infected Pts (A: n = 30) or Hds (B: n = 10) were surface stained with the FITC–anti-CD3 and PE-conjugated A13 or BB3 mAbs to identify Vδ1 or Vδ2 T cells and cytoplasmically stained with APC-anti–IL-17 mAb, immediately ex vivo or after 7 days of culture with Ca or PPD, and rIL-2 was added on day 4. Samples were analyzed by flow cytometry and gated on Vδ1 or Vδ2 T cells, and results were expressed as mean far red (IL-17) fluorescence intensity (MFI; arbitrary units, au) of IL-17⁺ cells among Vδ1 (■) or Vδ2 (□) T cells (A: mean ± SD from 30 Pts; B: mean ± SD from 10 Hds). None indicates PBMCs cultured in the absence of antigens. *P < .01 versus ex vivo or versus none. (A) **P < .01 versus Hds in panel B. (C,D) γδ T cells purified from HIV-1–infected patients (n = 10) or healthy donors (n = 10) by immunodepletion of CD4⁺ and CD8⁺ cells were cultured with irradiated (30 Gy) autologous monocytes in the presence of Ca, and SNs were recovered on day 4 and secreted IL-17 was measured by ELISA (C). Plates were read on a fluorimeter at the OD₄₅₀ and results expressed as picogram per milliliter referred to a standard curve. (−) indicates γδ T cells cultured in the absence of antigen. *P < .01 versus Hds. **P < .01 versus ex vivo or versus (−). (D) RNA from ex vivo–isolated or –cultured (d4) purified γδ T cells was reverse transcribed and amplified by Q-RT-PCR with specific primers for IL-17, compared with 18s. (−) indicates cells cultured in the absence of antigen. Results are expressed as fold increase of IL-17 mRNA versus 18s and are the mean ± SD from 10 Pts or 10 Hds. *P < .01 versus Hds. **P < .01 versus (−).