CD40LG and infection: We isolated and cultured approximately 54,040 class switched (CD20+IgD-IgM-IgA-) memory B cells from animal 8E-9 at 102 weeks post-SIVsmE660-infection (S5 Fig) and used high-throughput microneutralization assay to screen IgG-containing culture supernatants for neutralizing activity [29].