Mast cell activation by Mycobacterium tuberculosis: mediator release and role of CD48.
Mast cells (MC) are abundant in the lung and other peripheral tissue, where they participate in inflammatory processes against bacterial infections. Like other effector cells of the innate immune system, MC interact directly with a wide variety of infectious agents. This interaction results in MC activation and inflammatory mediator release. We demonstrated that MC interact with Mycobacterium tuberculosis, triggering the release of several prestored reagents, such as histamine and beta-hexosaminidase, and de novo synthesized cytokines, such as TNF-alpha and IL-6. A number of M. tuberculosis Ags, ESAT-6, MTSA-10, and MPT-63, have been implicated in MC activation and mediator release. A MC plasmalemmal protein, CD48, was implicated in interactions with mycobacteria because CD48 appeared to aggregate in the MC membrane at sites of bacterial binding and because Abs to CD48 inhibited the MC histamine response to mycobacteria. Cumulatively, these findings suggest that MC, even in the absence of opsonins, can directly recognize M. tuberculosis and its Ags and have the potential to play an active role in mediating the host's innate response to M. tuberculosis infection.
Muñoz
Samira
S
Unidad de Investigación Médica de Enfermedades Infecciosas y Parasitarias, Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
Hernández-Pando
Rogelio
R
Abraham
Soman N
SN
Enciso
Jose Antonio
JA
D000818:Animals; D000942:Antigens, Bacterial / Q000494:pharmacology; D015703:Antigens, CD / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D001422:Bacterial Adhesion / Q000276:immunology; D001426:Bacterial Proteins / Q000494:pharmacology; D000071178:CD48 Antigen; D002450:Cell Communication / Q000276:immunology; D017261:Glycosylphosphatidylinositols / Q000378:metabolism / Q000502:physiology; D006636:Histamine Release / Q000276:immunology; D018836:Inflammation Mediators / Q000378:metabolism*; D008297:Male; D008407:Mast Cells / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology* / Q000648:ultrastructure; D021962:Membrane Microdomains / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000942:Antigens, Bacterial; D015703:Antigens, CD; D001426:Bacterial Proteins; D000071178:CD48 Antigen; C117940:CFP-10 protein, Mycobacterium tuberculosis; C000604067:Cd48 protein, rat; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D017261:Glycosylphosphatidylinositols; D018836:Inflammation Mediators; C103339:MPT63 antigen, Mycobacterium tuberculosis; D011994:Recombinant Proteins