Candida albicans triggers proliferation and differentiation of hematopoietic stem and progenitor cells by a MyD88-dependent signaling.

As TLRs are expressed by hematopoietic stem and progenitor cells, these receptors may play a role in hematopoiesis in response to pathogens during infection. We showed here that inactivated yeasts and hyphae of Candida albicans induce in vitro the proliferation of purified murine hematopoietic stem and progenitor cells (Lin(-)c-Kit(+) Sca-1(+)) as well as their differentiation to lineage positive cells, through a MyD88-dependent pathway. These results indicate that TLR-mediated recognition of C. albicans by hematopoietic stem and progenitor cells may augment the host capability for rapidly replenishing the innate immune system during candidiasis.