Open AccessNegative modulation of suppressive HIV-specific regulatory T cells by IL-2 adjuvanted therapeutic vaccine
Author(s) -
Vedran Brezar,
Lylia Hani,
Mathieu Surénaud,
Audrey Hubert,
Christine Lacabaratz,
JeanDaniel Lelièvre,
Yves Lévy,
Nabila Seddiki
Publication year - 2017
Publication title -
plos pathogens
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.719
H-Index - 206
eISSN - 1553-7374
pISSN - 1553-7366
DOI - 10.1371/journal.ppat.1006489
Subject(s) - foxp3 , adjuvant , immunology , il 2 receptor , medicine , immune system , vaccination , immunotherapy , hiv vaccine , regulatory t cell , viral load , t cell , human immunodeficiency virus (hiv) , vaccine trial
The potential benefit in using IL-2 in immunotherapy for cancer and autoimmunity has been linked to the modulation of immune responses, which partly relies on a direct effect on Tregs populations. Here, we revisited the role of IL-2 in HIV infection and investigated whether its use as an adjuvant with therapeutic vaccination, impacts on HIV-specific responses. Antiretroviral therapy treated-patients were randomized to receive 4 boosts of vaccination (ALVACHIV/Lipo-6T, weeks 0/4/8/12) followed by 3 cycles of IL-2 (weeks 16/24/32) before treatment interruption (TI) at week40. IL-2 administration increased significantly HIV-specific CD4 + CD25 + CD134 + T-cell responses, which inversely correlated with viral load after TI (r = -0.7, p <0.007) in the vaccine/IL-2 group. IL-2 increased global CD25 + CD127 low FoxP3 + Tregs (p <0.05) while it decreased HIV- but not CMV- specific CD39 + FoxP3 + CD25 + CD134 + Tregs (p <0.05). HIV-specific Tregs were inversely correlated with IFN-γ producing specific-effectors (p = 0.03) and positively correlated with viral load (r = 0.7, p = 0.01), revealing their undesired presence during chronic infection. Global Tregs, but not HIV-specific Tregs, inversely correlated with a decrease in exhausted PD1 + CD95 + T-cells (p = 0.001). Altogether, our results underline the negative impact of HIV-specific Tregs on HIV-specific effectors and reveal the beneficial use of IL-2 as an adjuvant as its administration increases global Tregs that impact on T-cell exhaustion and decreases HIV-specific CD39 + Tregs by shifting the balance towards effectors.