Interaction of bacteria and stem cells in health and disease.

Adult stem and progenitor cells possess unique qualities of proliferative capacity and phenotypic plasticity making their potential interactions with pathogenic and commensal bacteria a significant factor in health and disease. This interaction may result in the hindrance of regenerative capacity and degenerative disease. In other contexts, bacterial-stem cell cross-talk plays an important role in regulating stem cell renewal and maintaining homeostasis. Some stems cells are involved in combating infections and modulating immune responses. The results of these interactions contribute significantly to the outcome of infectious disease. The unique characteristics of stem and progenitor cells also make them attractive targets for bacterial pathogenicity strategies. Several bacterial species have been shown to utilize stem cells as cellular niches or as a means to manipulate host-pathogen interactions. In some cases, bacteria can reprogram end-differentiated tissue cells towards stem-like cells, taking advantage of their unique properties for dissemination and persistence. The ability of bacteria to interfere in stem cell regulatory pathways can also contribute to hyperplastic growth and the development of cancer. In this review, we present current knowledge on the diverse interactions between bacteria and stem cells highlighting the consequences for health and disease.