CD4 and infection: Downregulation of NF-κB pathway components downstream of B-cell receptor activation, reduced expression of antibody production-associated genes (LILRB4, FCGR2B), and significant upregulation of CD22, a key negative regulator of B-cell activation, were found in CD4+ T-cell-specific PKCλ/ι knockout (KOSJ) group mice post-infection.