Selective immune modulation in seminal plasma during simian immunodeficiency virus infection despite systemic...

Immune modulation in the male genital tract during HIV infection is not well understood, despite its role in viral persistence and transmission. In a study using an SIV rhesus macaque model, we assessed viral RNA and 61 cytokines, chemokines, and growth factors in peripheral plasma (PP) and seminal plasma (SP). SIV RNA was found in both plasma samples, but the SP viral loads were more variable and decreased over time, independent of the systemic viremia. Baseline immune mediator profiles exhibited compartment-specific patterns, and principal component analysis demonstrated distinct clustering between PP and SP samples. Unlike the extensive systemic immune activation in PP, SIV infection in SP results in selective modulation involving CXCL1, IL-7, CCL4, and YKL-40, with these changes not correlating with the local viral loads. Our findings suggest that the seminal compartment is immunologically distinct, with selective inflammatory responses, highlighting the mechanisms that may influence viral persistence and transmission.