Pathways utilized by dendritic cells for binding, uptake, processing and presentation of antigens derived from HIV-1

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• The effectiveness of HIV vaccines relies on inducing robust HIV-specific T cell responses.
• Dendritic cells (DCs) are key antigen-presenting cells that initiate T cell immunity.
• Previous studies showed that DCs pulsed with inactivated HIV can control viral load.

Purpose of the Study:

• To investigate the mechanisms by which DCs process and present antigens from aldrithiol-2-inactivated HIV compared to infectious HIV-1.
• To elucidate the roles of specific DC receptors and cellular pathways in antigen presentation for HIV vaccine development.

Main Methods:

• Characterization of antigen presentation on MHC class I and II by DCs.
• Utilizing inhibitor studies to determine the dependency on viral fusion, endocytosis, and processing pathways.
• Comparing antigen presentation from aldrithiol-2-treated HIV versus infectious HIV-1.

Main Results:

• Antigen presentation on MHC class I and II was independent of DC receptors like DEC-205 and mannose receptor.
• MHC class I presentation required viral fusion and access to the classical endosomal pathway.
• MHC class II presentation depended on active endocytosis and virion degradation in acidified endosomes.

Conclusions:

• Chemically inactivated HIV virions are efficiently processed by DCs for antigen presentation.
• The findings provide insights into DC binding, uptake, and processing of inactivated HIV.
• This knowledge can inform the design of more effective HIV vaccines targeting T cell responses.