HIV Infection and Spread between Th₁₇ Cells

Area of Science:

• Immunology
• Virology
• Cell Biology

Background:

• Human Immunodeficiency Virus (HIV) primarily infects CD4+ T cells, including T helper 17 (Th17) cells, which are crucial for mucosal immunity.
• Th17 cells have a complex role, contributing to gut integrity but also inflammation and autoimmunity.
• The specific antiviral functions and involvement of Th17 cells in HIV pathogenesis, particularly at mucosal sites, remain incompletely understood.

Purpose of the Study:

• To review current knowledge on the role of Th17 cells in HIV pathogenesis at mucosal surfaces.
• To examine the mechanisms of HIV-1 spread between T cells, considering both cell-to-cell and cell-free transmission.
• To highlight Th17 cells as potential targets for interventions aimed at preventing or reducing HIV transmission.

Main Methods:

• This study is a review, synthesizing existing research findings and insights.
• It analyzes in vitro studies on HIV transmission modes (cell-to-cell vs. cell-free).
• It discusses the implications of in vivo conditions and the presence of both infected cells and free virus in bodily fluids.

Main Results:

• Th17 cells are permissive to HIV replication and play a significant role in HIV-1 pathogenesis at mucosal sites.
• HIV-1 can spread through direct cell-to-cell contact or via cell-free viral particles, with ongoing debate about the efficiency of each mode.
• Bodily fluids like breast milk, semen, and vaginal secretions contain a mixture of infected cells and free virus, suggesting dual transmission routes are utilized in vivo.

Conclusions:

• Th17 cells are key players in HIV pathogenesis and represent a critical target for therapeutic and preventative strategies.
• Further research is needed to fully elucidate the in vivo mechanisms of HIV-1 transmission between T cells.
• Understanding the interplay between Th17 cells and HIV is essential for developing effective interventions against HIV infection and transmission.