Differential Mast Cell Response to Different Bacteria

ABSTRACT

Mast cells (MCs) are highly specialized for the synthesis and secretion of pharmacologically active products. Although implicated in various inflammatory diseases such as asthma, allergy, multiple sclerosis, and Crohn's disease, MCs have also an important physiologic role in immunosurveillance and modulation of host's innate immune responses following bacterial infection. Here, we present that MCs show varying capability of recognizing and responding to different bacteria. Whereas MCs were readily degranulated and released neutrophil chemoattractants in response to E. coli or S. aureus infections, they failed to degranulate during S. typhimurium infections. Consequently, E. coli infections were associated with a vigorous neutrophil response and early bacterial clearance whereas S. typhimurium infections were associated limited neutrophil influx and bacterial multiplication at sites of infection. Interestingly, injection of compound 48/80, a MC specific activator, at sites of S. typhimurium infection triggered MC mediated neutrophil influx and bacterial clearance.