HLA-C and infection: While inhibiting infection, reducing ARDS and suppressing deleterious aspects of the immune response such as cytokine storm, Ag/MHC surface exosomes present in convalescent plasma, particularly those from APC macrophages and DC and B cells, can also serve to augment the antiviral immune response by acting as miniature nano APC (Rodrigues, Fan, Lyon, Wan, & Hu, 2018).