Fig. 3.
Suggested mechanism for amplification of SARS-CoV-2αgal vaccine immunogenicity by anti-Gal mediated targeting to APC. Inactivated SARS-CoV-2 presenting α-gal epitopes (SARS-CoV-2αgal) is used as a vaccine example. Step 1- Anti-Gal IgM and IgG bind to α-gal epitopes on the vaccinating virus at the vaccination site, activate the complement system which generates complement cleavage chemotactic peptides that recruit APC such as dendritic cells and macrophages. Step 2- Anti-Gal IgG coating the virus targets it for active extensive uptake by the recruited dendritic cells and macrophages, via Fc/Fcγ receptors (FcγR) interaction. Step 3- These APC transport the internalized virus vaccine to the regional lymph nodes and process the virus antigens. Within the lymph nodes, the APC present the immunogenic virus peptides on class I and class II MHC molecules for the activation of SARS-CoV-2 specific CD8 + and CD4 + T cells, respectively. TCR- T cell receptor. Modified from [26].