RÉSUMÉ
We evaluated the safety and viral rebound, after analytical treatment interruption (ATI), of vedolizumab and ART in recent HIV-1 infection. We used this model to analyze the impact of α4ß7 on the HIV-1 reservoir size. Participants started ART with monthly Vedolizumab infusions and ATI was performed at week 24. Biopsies were obtained from ileum and caecum at baseline and week 24. Vedolizumab levels, HIV-1 reservoir, flow cytometry and cell-sorting and antibody competition experiments were assayed. Vedolizumab was safe and well-tolerated. No participant achieved undetectable viremia off ART 24 weeks after ATI. Only a modest effect on the time to achieve >1000 HIV-RNA copies/mL and the proportion of participants off ART was observed, being higher compared to historical controls. Just before ATI, α4ß7 expression was associated with HIV-1 DNA and RNA in peripheral blood and with PD1 and TIGIT levels. Importantly, a complete blocking of α4ß7 was observed on peripheral CD4+ T-cells but not in gut (ileum and caecum), where α4ß7 blockade and vedolizumab levels were inversely associated with HIV-1 DNA. Our findings support α4ß7 as an important determinant in HIV-1 reservoir size, suggesting the complete α4ß7 blockade in tissue as a promising tool for HIV-cure combination strategies.
