CD40LG and infection: Polyreactive secretory-like IgA (SCIgA) and secretory-like IgM (SCIgM) antibodies reconstituted from plasma-derived polymeric immunoglobulins and SC (12), when associated with the enteropathogen Shigella flexneri, have proven to delay infection of polarized epithelial cell monolayers used as a surrogate of the intestinal barrier (13).