CD40LG and HIV infectious disease: Perturbations of mature B cells include an impact on naïve cells, that are reduced in number and function early after HIV infection (7), and memory B cells, which seem to be the most affected subset, showing lower numbers of switched IgM-IgD- memory cells, expansion of IgM-only memory cells (8) and an aberrant Tissue-like memory (TLM) repertoire (9).