CD79A and infection: sIgA is generally the first-line defense of the host immune system against infection by eliminating invasive pathogens and maintaining mucosal commensals.53 Significantly, the selectively outgrowing IgA-coated microbes genetically and functionally resemble a microbial pathotype with reduced virulence factors but increased adherent or invasive propensity and replication potential in macrophages.32 sIgA-coated bacteria were also detected in SHR and WKY intestines.