We have located links that may give you full text access.
JOURNAL ARTICLE
RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
Mycobacterium tuberculosis phagosomes exhibit altered calmodulin-dependent signal transduction: contribution to inhibition of phagosome-lysosome fusion and intracellular survival in human macrophages.
Journal of Immunology 2001 March 2
Mycobacterium tuberculosis successfully parasitizes macrophages by disrupting the maturation of its phagosome, creating an intracellular compartment with endosomal rather than lysosomal characteristics. We have recently demonstrated that live M. tuberculosis infect human macrophages in the absence of an increase in cytosolic Ca(2+) ([Ca(2+)](c)), which correlates with inhibition of phagosome-lysosome fusion and intracellular viability. In contrast, killed M. tuberculosis induces an elevation in [Ca(2+)](c) that is coupled to phagosome-lysosome fusion. We tested the hypothesis that defective activation of the Ca(2+)-dependent effector proteins calmodulin (CaM) and CaM-dependent protein kinase II (CaMKII) contributes to the intracellular pathogenesis of tuberculosis. Phagosomes containing live M. tuberculosis exhibited decreased levels of CaM and the activated form of CaMKII compared with phagosomes encompassing killed tubercle bacilli. Furthermore, ionophore-induced elevations in [Ca(2+)](c) resulted in recruitment of CaM and activation of CaMKII on phagosomes containing live M. tuberculosis. Specific inhibitors of CaM or CaMKII blocked Ca(2+) ionophore-induced phagosomal maturation and enhanced the bacilli's intracellular viability. These results demonstrate a novel role for CaM and CaMKII in the regulation of phagosome-lysosome fusion and suggest that defective activation of these Ca(2+)-activated signaling components contributes to the successful parasitism of human macrophages by M. tuberculosis.
Full text links
Trending Papers
Cardiovascular Disease in Diabetes and Chronic Kidney Disease.Journal of Clinical Medicine 2023 November 9
Monitoring Macro- and Microcirculation in the Critically Ill: A Narrative Review.Avicenna Journal of Medicine 2023 July
Euglycemic Ketoacidosis in Two Patients Without Diabetes After Introduction of Sodium-Glucose Cotransporter 2 Inhibitor for Heart Failure With Reduced Ejection Fraction.Diabetes Care 2023 November 22
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
Read by QxMD is copyright © 2021 QxMD Software Inc. All rights reserved. By using this service, you agree to our terms of use and privacy policy.
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app