Env-specific IgA from viremic HIV-infected subjects compromises antibodydependent cellular cytotoxicity

MARÍA JULIA RUIZ; NATALIA LAUFER; PEDRO CAHN; HORACIO SALOMÓN; GABRIELA TURK; YANINA GHIGLIONE; MARÍA PÍA HOLGADO; JULIANA FALIVENE; OMAR SUED; MARÍA EUGENIA SOCIAS; MARÍA MAGDALENA GHERARDI; LUIS D. GIAVEDONI; ANA MARÍA RODRIGUEZ

JOURNAL OF VIROLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2016 vol. 90 p. 670 - 681

0022-538X

Elucidating thefactors that modulate HIV-specific antibody-dependent cellular cytotoxicity(ADCC) will help to understand its role in HIV immunity. The aim of this studywas to determine whether IgA couldmodify ADCC magnitude in HIV infection, abrogatingits protective role. Plasma from 20 HIV+ subjects enrolledduring primary HIV infection (PHI), 10 chronically infected subjects (Chronics)and 7 Elite Controllers (EC) was used. ADCC was determined using a fluorometricADCC assay, before and after plasma IgA removal. Data was analyzed usingnon-parametric statistics. ADCC was documented in 80% of PHI enrollmentsamples and in 100% of PHI 12-month samples, Chronics and ECs; it peaked afteracute infection, reached a plateau in chronic infection and decreased after ARTinitiation. Significant associations between ADCC and disease progression wereonly found after IgA plasma removal from 12-month PHI samples: ADCC magnitudenot only increased after IgA removal but also correlated with CD4+T-cellpreservation. This work provides evidence that gp120-specific IgA was capableof modifying ADCC responses during natural HIV infection for the first time andadds to similar evidence provided in other settings. Furthermore, it underscoresthe complexity of ADCC phenomenon and will help to understand its underlyingmechanisms.