Blocking α4β7integrin binding to SIV does not improve virologic control

An antibody is not the antidote An HIV therapeutic that would give long-term remission without sustained antiretroviral therapy (ART) is a long-term goal. Byrareddyet al. [Science 354 , 197 (2016)] reported that treating simian immunodeficiency virus (SIV)–positive macaques with an antibody against integrin α4 β7 during and after ART results in sustained virologic control after stopping all treatment. Three studies in this issue question the reproducibility of that result. Di Mascioet al. sequenced the virus used in the 2016 study and found that it was a variant with a stop codon in thenef gene rather than a wild-type virus. Abbinket al. used the same antibody for α4 β7 as before but tested control of a more commonly used pathogenic virus. Iwamatoet al. used the samenef -stop virus as in the earlier paper but combined the antibody against the integrin with an antibody against the SIV envelope glycoprotein, which also blocks viral binding of the integrin. None of these three new studies found that treating with the antibody had any effect on virologic control after stopping ART treatment.Science , this issue p.1025 , p.1029 , p.1033