Phenotype and function of peripheral blood γδ T cells in HIV infection with tuberculosis

BACKGROUND: Although γδ T cells play an essential role in immunity against Human Immunodeficiency Virus (HIV) or Mycobacterium tuberculosis (MTB), they are poorly described in HIV infection with tuberculosis (TB). METHODS: The phenotypic and functional properties of peripheral blood γδ T cells in patients with HIV/TB co-infection were analyzed compared to healthy controls and patients with HIV mono-infection or TB by direct intracellular cytokine staining (ICS). RESULTS: The percentage of Vδ(1) subset in HIV/TB group was significantly higher than that in TB group, while the decreased frequency of the Vδ(2) and Vγ(2)Vδ(2) subsets were observed in HIV/TB group than in TB group. The percentage of CD4(+)CD8(-) Vδ(2) subset in HIV/TB group was markedly lower than in TB group. However, the percentage of CD4(+)CD8(+) Vδ(2) subset in HIV/TB group was markedly higher than HIV group or TB group. A lower percentage TNF-α and a higher percentage of IL-17A of Vδ(2) subset were observed in HIV/TB group than that in HIV mono-infection. The percentage of perforin-producing Vδ(2) subset was significantly lower in HIV/TB group than that in HIV group and TB group. CONCLUSIONS: Our data suggested that HIV/TB co-infection altered the balance of γδ T cell subsets. The influence of HIV/TB co-infection on the function of γδ T cells to produce cytokines was complicated, which will shed light on further investigations on the mechanisms of the immune response against HIV and/or MTB infection.