Bacterial infections are still the major cause of morbidity and mortality, and innate immunity is the first line of host defense against infections. The overall objective of this project is to elucidate how innate immunity protects the host from infections with Gram-positive bacteria and how the host response to bacterial components causes clinical manifestations and pathologic changes associated with infections. This project investigates the main component of Gram-positive bacterial cell walls, peptidoglycan, which can reproduce several major clinical manifestations of bacterial infections. This laboratory has identified a novel family of four pattern recognition proteins in humans that recognize peptidoglycan (PGRPs). These human PGRPs are differentially expressed in the bone marrow, neutrophils, liver, esophagus, tonsils, and thymus, and are highly homologous to the family of 12 insect PGRPs. This project will test the hypothesis that mammalian PGRPs interact with peptidoglycan and bacteria and are involved in innate immunity to bacteria. Specifically, the objective will be to identify the function of PGRPs in mammalian immunity using two approaches: First, it will be determined if PGRP-S knockout mice (generated in this laboratory) are immunodeficient, by testing the following aspects of their immunity: (i) development of lymphoid organs and cells; (ii) susceptibility to infections; (iii) inflammatory responses; (iv) induction of cytokines and chemokines;(v) chemotactic and phagocytic responses; and (vi) antibody responses. Second, the functions of the remaining PGRPs (PGRP-L, PGRP-I-alpha, and PGRP-I-beta) will be determined by identifying: (i) tissues and cell types that express these PGRPs; (ii) subcellular localization of each PGRP; (iii) their ligands; (iv) association of PGRPs with other proteins; (v) ability of these PGRPs to induce acute-phase response and uptake of bacteria; (vi) functional domains of these PGRPs; and (vii) inhibitory effects of soluble PGRP-S on the functions of transmembrane PGRPs. This study may discover a new mechanism of innate immunity and a new immunodeficiency, and may provide tools for developing new preventive and therapeutic measures against infections with Gram-positive bacteria.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI028797-10A1
Application #
6571404
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Korpela, Jukka K
Project Start
1992-07-01
Project End
2007-11-30
Budget Start
2002-12-01
Budget End
2003-11-30
Support Year
10
Fiscal Year
2003
Total Cost
$338,625
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Kashyap, Des R; Kuzma, Marcin; Kowalczyk, Dominik A et al. (2017) Bactericidal peptidoglycan recognition protein induces oxidative stress in Escherichia coli through a block in respiratory chain and increase in central carbon catabolism. Mol Microbiol 105:755-776
Dziarski, Roman; Park, Shin Yong; Kashyap, Des Raj et al. (2016) Pglyrp-Regulated Gut Microflora Prevotella falsenii, Parabacteroides distasonis and Bacteroides eggerthii Enhance and Alistipes finegoldii Attenuates Colitis in Mice. PLoS One 11:e0146162
Jing, Xuefang; Zulfiqar, Fareeha; Park, Shin Yong et al. (2014) Peptidoglycan recognition protein 3 and Nod2 synergistically protect mice from dextran sodium sulfate-induced colitis. J Immunol 193:3055-69
Kashyap, Des Raj; Rompca, Annemarie; Gaballa, Ahmed et al. (2014) Peptidoglycan recognition proteins kill bacteria by inducing oxidative, thiol, and metal stress. PLoS Pathog 10:e1004280
Park, Shin Yong; Jing, Xuefang; Gupta, Dipika et al. (2013) Peptidoglycan recognition protein 1 enhances experimental asthma by promoting Th2 and Th17 and limiting regulatory T cell and plasmacytoid dendritic cell responses. J Immunol 190:3480-92
Dziarski, Roman; Kashyap, Des Raj; Gupta, Dipika (2012) Mammalian peptidoglycan recognition proteins kill bacteria by activating two-component systems and modulate microbiome and inflammation. Microb Drug Resist 18:280-5
Park, Shin Yong; Gupta, Dipika; Kim, Chang H et al. (2011) Differential effects of peptidoglycan recognition proteins on experimental atopic and contact dermatitis mediated by Treg and Th17 cells. PLoS One 6:e24961
Park, Shin Yong; Gupta, Dipika; Hurwich, Risa et al. (2011) Peptidoglycan recognition protein Pglyrp2 protects mice from psoriasis-like skin inflammation by promoting regulatory T cells and limiting Th17 responses. J Immunol 187:5813-23
Kashyap, Des Raj; Wang, Minhui; Liu, Li-Hui et al. (2011) Peptidoglycan recognition proteins kill bacteria by activating protein-sensing two-component systems. Nat Med 17:676-83
Saha, Sukumar; Jing, Xuefang; Park, Shin Yong et al. (2010) Peptidoglycan recognition proteins protect mice from experimental colitis by promoting normal gut flora and preventing induction of interferon-gamma. Cell Host Microbe 8:147-62

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