Study of HIV-1 Transmission across Cervical Mucosa to Tonsil Tissue Cells using an Organ Culture
Phalguni Gupta, Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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.
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.
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.