Erythrocytes´ presence enhance HIV production on monocyte derived macrophages (MDM)

LUCIA FAZZI; ROBERTO DANIEL RABINOVICH; MARIA MERCEDES ÁVILA

Barcelona

Congreso; 7th Vaccine and ISV Congress; 2013

The International Society for Vaccines

Erythrocytes´ presence enhance HIV production on monocyte derived macrophages (MDM) Fazzi Lucia, Rabinovich Daniel R, Avila Maria M Instituto de Investigaciones Biomédicas en Retrovirus y Sida, (INBIRS, formerly known as National Reference Center for Aids, CNRS), University of Buenos Aires/CONICET, Buenos Aires, Argentina. Background: Erythrocytes of HIV+ individuals present p24 Antigen, RNA-HIV and bounded-specific antibodies. HIV-erythrocyte association was described to be mediated by immune complexes or complement factors and DARC in the erythrocyte membrane. Given that macrophages are widely known reservoirs established at the first stages of infection and the close contact of erythrocyte and macrophages, this work focuses on the capacity of the HIV produced by macrophages to bind to erythrocytes membrane. Methods: MDM were obtained from healthy donors’ buffy coats and infected with BaL virus strain. Erythrocytes were obtained from healthy donors (one Afro-American woman DARC-), and purified with Dextran. After 7 and 10 days post inoculation (pi) MDM were incubated with erythrocytes DARC+, DARC– and RPMI. P24Ag was determined in erythrocytes supernatant. The supernatant of the MDM incubated with RPMI was fractioned in 3, one to measure p24 and other 2 incubated with purified erythrocytes DARC+ and DARC-. P24 was determined. Results: The total amount of virus produced by MDM incubated with erythrocytes was significantly higher than the amount produced when they were incubated with RPMI (p=0.005). The binding capacity of the virus produced by MDM was analyzed with erythrocytes DARC+ and DARC- and no differences were observed between donors. The percentages observed were similar to those obtained when the erythrocytes were incubated with different viral stocks. Similar results were obtained in different pi days. Conclusions: Due to the importance of macrophages and erythrocyte described, and as it was demonstrated here, the presence of erythrocytes may increase viral production of infected MDM, this fraction should be thoroughly considered in the pathogenesis of HIV infection, given that this close contact always occurs in the infected patient during the early stage of infection. So far, the presence or absence of DARC showed no relevance, therefore, other receptors involved in the binding process should be further studied.