ADCC responses arising during acute/early HIV infection do not prevent rapid disease progression María Julia Ruiz 1, Yanina Ghiglione1, María Eugenia Socías3, Natalia Laufer1 2, Pedro Cahn2, 3, Omar Sued3, María Magdalena Gherardi1,Horacio Salomon1, Ana María Rodriguez1, Gabriela Turk1. 1 Instituto de Investigaciones Biomédicas en Retrovirus y Sida, Universidad de Buenos Aires/CONICET, Buenos Aires, Argentina. 2 Hospital Juan A. Fernández, Unidad Enfermedades Infecciosas, Buenos Aires, Argentina. 3. Fundación Huesped, Buenos Aires, Argentina ADCC is an effector mechanism known to play a relevant role in antiviral immunity . Data coming from HIV infected EC and humans and monkeys that were vaccinated in indifferent trials suggest that these activities may protect from infection and progression. However, the role of these antibodies in natural infection is still controversial. INTRODUCTION AIM: To establish the potential role of ADCC-mediating HIV-specific antibodies in the control of acute/early primary HIV infection (PHI) and disease progression M&M Samples: Plasma from 20 HIV+ PHI subjects (baseline and 12-month samples)10 HAART-naïve chronically infected patients (C) and 7 Elite Controllers (EC). ADCC assay: ADCC was analyzed using the rapid and flourometric ADCC assay (RFADCC, V.R. Gómez-Román et al. / Journal of Immunological Methods 308 (2006) 53–67 ) which relies on PKH-26 and CFSE staining of gp120-coated target cells (CEM–NKR) before the addition of subject’s plasma and effectors cells (PBMCs from healthy donors). Percentage of ADCC-killing and ADCC titers were determined. Uncoated Coated PHI all PHI>350 cells/ml “Non-progressors” PHI<350 cells/ml “Progressors” 9,6 % 53.1 %

ADCC Responses and Disease Progression ADCC Responses in phi subjects , chronically infected patients and elite controllers ADCC Responses and Disease Progression

Grupo Argentino de Seroconversión CONCLUSIONS ADCC responses arose early after infection and increased during the first year post-infection in untreated patients The initiation of HAART during the first year post-infection modifies ADCC responses No association was found between the magnitude of ADCC responses and the evolution of acute infection or early disease progression ACKNOWLEDGMENTS María Eugenia Socías Omar Sued Pedro Cahn María Julia Ruiz Yanina Ghiglione Natalia Laufer Maria Magdalena Gherardi Horacio Salomon Ana Maria Rodriguez Gabriela Turk Grupo Argentino de Seroconversión Study Group