308. Characterization of SIV infection in the male genital tract of juvenile macaques

Abstract

Reproductive organs contribute infected cells and free viral particles to semen in human immunodeficiency type-1 (HIV-1) infected individuals, increasing the risk of infection from the HIV-1 positive male to the mother and ultimately to the offspring. The majority of information gathered with respect to the HIV-1 burden in the male reproductive tract (MGT) have been conducted in tissues obtained on autopsies of testis, prostate and epididymis of individuals that die from AIDS. Therefore, little is known about the progression and pathogenesis of the infection within these organs. Investigating the mechanism of the spread of HIV-1 in the cells and tissues of the MGT, particularly during the asymptomatic stage, remains a critical task. Infection of macaques with simian immunodeficiency virus (SIV) is a useful animal model for studies of mucosal transmission and viral transmission via breastfeeding. In this study eight juvenile macaques (2.5 yo) were infected with SIVmac for a period of 3–6 months and testis and epididymis tissue were collected in two intervals, 3 and 6 months post-infection. To determine SIV progression and pathogenesis in the MGT we have used EM, immunohistochemistry, confocal microscopy and immunoblotting. Our preliminary EM obtained via analysis of testis and epididymis tissue of SIV infected macaques show the presence of elongated spermatids in the epididymis. Scattered viral like SIV particles were observed in the testis and epididymal lumen, principally associated with aberrant germ cells. Necrosis of epididymal tissue was also observed, potentially due to the SIV burden in this organ. The data indicate that SIV infected juvenile macaques are a potential model for studying HIV-1 pathogenesis and its effect in spermatogenesis as well as the immune response of testis in a species that is closely related to humans.