Study of HIV-1 transmission across cervical mucosa to tonsil tissue cells using an organ culture.

PROBLEM: SIV model indicates that upon traversing the cervicovaginal mucosa, SIV/SIV-infected cells migrate to regional lymph nodes where active replication occurs prior to systemic virus dissemination. The purpose of the study is to develop a model to study early HIV-1 transmission events that occur after crossing the cervical mucosa into regional lymph nodes. METHODS OF STUDY: We developed an organ culture model combining intact cervical tissue explants and tonsil tissue cells as the surrogate draining lymphoid tissue. Viral replication was measured by HIV-1 p24 production, quantification of viral DNA and viral RNA expression in tonsil cells.
RESULTS: In this combined organ culture model, transmission of cell-free and cell-associated R5- and X4-tropic HIV-1 through the cervical mucosa to tonsilar cells was observed as determined by HIV-1 p24 in culture supernatant, and the presence of HIV-1 proviral DNA, HIV-1 p24 gag protein in CD4(+) , CD11c(+) , CD68(+) cells, and expression of HIV-1 mRNA expressing CD45RO(+)  CD4 T cells in tonsil cells. Furthermore, co-receptor usage of HIV-1 in tonsil cells correlated with inoculating virus tropism.
CONCLUSIONS: Our combined cervix-tonsil organ culture could serve as an experimental model to study the earliest stages of HIV-1 transmission through cervicovaginal mucosa to its proximal lymph nodes.