Background Human immunodeficiency virus type 1 (HIV-1) causes impairment of T and B cell responses, which begins during the acute phase of infection and is not completely restored by antiretroviral treatment. Regulatory T cell (Tregs) can improve overall disease outcome by controlling chronic inflammation but may also suppress beneficial HIV-1 specific immune responses. We aimed to analyze the profile of Tregs and their correlation with the status of T cells activation, the expression of IL-2 and IFNγ and the profile of HIV-1 specific antibodies response in Mozambican people living chronically with HIV-1 (PLWH-C). Results In PLWH-C, the proportion of total Tregs was positively correlated with the proportion of IL-2+CD4 T cells (r = 0.647; p = 0.032) and IL-2+IFNγ+CD8 T cells (r = 0.551; p = 0.014), while the proportions of Helios+Tregs correlated inversely with levels of IL-2+CD8 T cells (r = − 0.541; p = 0.017). Overall, PLWH-C, with (82%) or without virologic suppression (64%), were seronegative for at least HIV-1 p31, gp160 or p24, and the breadth of antibody responses was positively correlated with proportions of CD38+HLA-DR+CD8 T cells (r = 0.620; p = 0.012), viral load (r = 0.452; p = 0.040) and inversely with absolute CD4 T cells count (r = − 0.481; p = 0.027). Analysis of all individuals living HIV-1 showed that the breadth of HIV-1 antibody responses was inversely correlated with the proportion of Helios+Tregs (r = − 0.45; p = 0.02). Conclusion Among Mozambican people living with HIV-1, seronegativity to some HIV-1 proteins is common, particularly in virologically suppressed individuals. Furthermore, lower diversity of HIV-specific antibodies is correlated to lower immune activation, lower viral replication and higher CD4 counts, in PLWH-C. Elevation in the proportion of Helios+Tregs is related to a reduction of CD8 T expressing intracellular IL-2, in PLWH-C, but may contribute to impairment of B cell function.

Background: Human immunodeficiency virus type 1 (HIV-1) causes impairment of T and B cell responses, which begins during the acute phase of infection and is not completely restored by antiretroviral treatment. Regulatory T cell (Tregs) can improve overall disease outcome by controlling chronic inflammation, but may also suppress beneficial HIV-1 specific immune responses. We analyzed immune alterations, including Tregs, and their clinical significance in Mozambican people living chronically with HIV-1 (PLWH-C). Results: In PLWH-C, the proportion of total Tregs was positively correlated with the proportion of IL-2+CD4 T cells (r=0.647; p=0.032) and IL-2+IFNg+CD8 T cells (r=0.551; p=0.014), while the Helios+Tregs correlated inversely with levels of IL-2+CD8 T cells (r= -0.541; p=0.017). Overall, PLWH-C, with (82%) or without virologic suppression (64%), were seronegative for at least HIV-1 p31, gp160 or p24, and the breadth of antibody responses was positively correlated with proportions of CD38+HLA-DR+CD8 T cells (r=0.620; p=0.012), viral load (r=0.452; p=0.040) and inversely CD4 T cells count (r=-0.481; p=0.027). Analysis of all individuals living HIV-1 showed that the breadth of HIV-1 antibody responses was inversely correlated with the proportion of Helios+Tregs (r=-0.45; p=0.02). Conclusion: Among Mozambican patients living with HIV-1, seronegativity to some HIV-1 proteins is common mostly in virologically suppressed individuals. Low diversity of HIV-specific antibodies is correlated to indicators of disease control during ART. Elevation in the proportion of Helios+Tregs is related to a reduction of CD8 T expressing intracellular IL-2 but may contribute to impairment of B cell function.