Dolasia, Komal and Nazar, Faiza and Mukhopadhyay, Sangita (2020) Mycobacterium tuberculosis PPE18 protein inhibits MHC class II antigen presentation and B cell response in mice. European Journal of Immunology. ISSN 0014-2980 (In Press)

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Abstract

PPE18 protein belongs to PE/PPE family of Mycobacterium tuberculosis. We reported earlier that PPE18 protein provides survival advantage to M. tuberculosis during infection. In the current study, we found that PPE18 inhibits major histocompatibility complex (MHC) class II-mediated antigen presentation by macrophages in a dose dependent manner without affecting the surface level of MHC class II or co-stimulatory molecules. PPE18 does not affect antigen uptake or presentation of pre-processed peptide by macrophages. Antigen degradation was found to be inhibited by PPE18 protein due to perturbation in phagolysosomal acidification. PPE18-mediated inhibition of MHC class II antigen presentation caused poorer activation of CD4 T cells. Mice infected with M. smegmatis expressing PPE18 exhibited reduced maturation and activation of B cells and had decreased Mycobacteria specific antibody titers. Thus M. tuberculosis probably utilizes PPE18 to inhibit MHC class II antigen presentation causing poorer activation of adaptive immune responses. This study may be useful in understanding host-pathogen interaction and open up directions of designing novel therapeutics targeting PPE18 to tackle this nefarious pathogen.

Item Type:	Article
Subjects:	Molecular Biology
Depositing User:	Users 2 not found.
Date Deposited:	10 Nov 2020 17:53
Last Modified:	10 Nov 2020 17:53
URI:	http://cdfd.sciencecentral.in/id/eprint/980

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