Host Immune Responses to Mycoplasmas
Steven M. Szczepanek and Lawrence K. Silbart
from: Mollicutes: Molecular Biology and Pathogenesis (Edited by: Glenn F. Browning and Christine Citti). Caister Academic Press, U.K. (2014)
The atypical characteristics of mycoplasmas are often associated with dysregulated host immune responses, which allow these pathogens to occupy an ecological niche associated with mucosal surfaces (and occasionally beyond). The lack of a cell wall and the presence of variable surface lipoproteins are paramount amongst these uncommon features, and host defense includes an intricate innate immune signaling system that includes TLRs, cytokines, and chemotactic molecules to attract, alert and activate leukocytes during infection. Mycoplasmas are adept at manipulating many of these signals to their own advantage, resulting in mutualistic relationships in some cases, or insidious chronic infections in others. Successful resolution of disease usually depends on robust humoral and cell-mediated immune responses, but such responses can take weeks to develop, thereby allowing the bacteria an opportunity to adapt to their environment and gain a foothold in colonized tissues. For this reason, successful prophylactic vaccines block initial colonization, thereby preventing the subsequent over-exuberant inflammatory and dysregulated adaptive immune responses. This chapter examines the intricate interplay between highly evolved host immune responses versus the highly adaptable mycoplasmas, with an eye towards identifying gaps in our knowledge that must be addressed in future research read more ...