Semen acts as an adjuvant promoting the adaptive immune response against HSV-2

A. VARESE; F. REMES LENICOV; M. GONZALEZ PRINZ; A. MERLOTTI; S. SIMULA; F. ERRA DÍAZ; J. GEFFNER; A. CEBALLOS

Buenos Aires

Congreso; Reunion Anual SAI; 2015

Sociedad Argentina de Inmunología

Semen is the main vector of a wide range of sexually transmitted infectious (STI). It can also induce immunomodulatory actions that favor tolerance to paternal alloantigens. If semen affects establishment and progression of STI has surprisingly not been investigated. Our hypothesis is that semen, beyond a vehicle for pathogens, modulates anti-infectious immunity.Six-week-old female BALB/c mice were inoculated ivag with seminal vesicles fluid (SV) or PBS +: a) HSV-2 (105pfu), or b) inactivated HSV-2 (104pfu) (vaccination) and then challenged with a lethal-HSV-2-dose. SV was extracted post-mortem from 10-week-old BALB/c males. Virus titters in vaginal fluids were measured by pfu. HSV-2 in vagina and spinal cord was quantified by qPCR. Iliac lymph nodes and genital mucosa cells were recovered and cell populations were characterized by flow cytometry and cytokines production was assessed by ELISA.We observed that SV doesn?t affect HSV-2 infectivity in-vitro nor virus attachment and disease progression in HSV-2-infected mice (a). However, SV-vaccinated mice (b) showed 90% survival (control 10%; n=20; p<0.001) and minor disease progression (n=20; p<0.001). We found similar viral loads in vaginal washes and vaginal epithelium, but we found that SV-vaccinated mice had impaired viral access to central nervous system (CNS) (n=10; p<0.01). SV-vaccinated mice had increased IFN-γ production (n=20 p<0.05) and augmented TCD8+ cells (n=4; p<0.01) at site of infection. When analyzing early events after vaccination, SV-vaccinated mice showed elevated secretion of IFN-γ, TNF-α and IL-6.Our results suggest that SV acts as an adjuvant, promotes adaptive immunity and impairing HSV-2 dissemination to CNS.