CD19 and infection: Figure 4A illustrates the gating strategy to identify CD19 + CD40 + B cells, and Figure 4B illustrates the gating strategy to identify CD4 + T cells and CD8 + T cells. As shown in Figure 4C, rGDSH-G349 recruited more CD19 + CD40 + B cells and CD8 + T cells (from CD3 + T cells) than parent GD-SH-01 in the spleen after i.m. infection.