title: CD45-mediated signaling pathway is involved in Rhizoctonia bataticola lectin (RBL)-induced proliferation and Th1/Th2 cytokine secretion in human PBMC.
abstract: We earlier reported the mitogenic and immunostimulatory activities of Rhizoctonia bataticola lectin (RBL), purified from phytopathogenic fungus R. bataticola in human PBMC. The lectin demonstrates specificity towards glycoproteins containing complex N-glycans. Since CD45-protein tyrosine phosphatase that abundantly expresses N-glycans is important in T-cell signaling, the study aimed to investigate the involvement of CD45 in the immunomodulatory activities of RBL. Flowcytometry and confocal microscopy studies revealed that RBL exhibited binding to PBMC and colocalized with CD45. The binding was comparable in cells expressing different CD45 isoforms-RA, -RB and -RO. CD45 blocking antibody reduced the binding and proliferation of PBMC induced by RBL. CD45-PTPase inhibitor dephostatin inhibited RBL-induced proliferation, expression of CD25 and pZAP-70. RBL-induced secretion of Th1/Th2 cytokines were significantly inhibited in presence of dephostatin. Also, dephostatin blocked phosphorylation of p38MAPK and STAT-5 that was crucial for the biological functions of RBL. The study demonstrates the involvement of CD45-mediated signaling in RBL-induced PBMC proliferation and Th1/Th2 cytokine secretion through activation of p38MAPK and STAT-5.
authors.affiliation: National Centre for Cell Science, Ganeshkhind, Pune 411007, India.
authors.forename: Radha
authors.initials: R
authors.lastname: Pujari
authors.forename: Sachin M
authors.initials: SM
authors.lastname: Eligar
authors.forename: Natesh
authors.initials: N
authors.lastname: Kumar
authors.forename: Nagaraja N
authors.initials: NN
authors.lastname: Nagre
authors.forename: Shashikala R
authors.initials: SR
authors.lastname: Inamdar
authors.forename: Bale M
authors.initials: BM
authors.lastname: Swamy
authors.forename: Padma
authors.initials: P
authors.lastname: Shastry
mesh_terms: D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D056747:Immunomodulation; D037102:Lectins / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D010766:Phosphorylation; D012232:Rhizoctonia / Q000276:immunology*; D050799:STAT5 Transcription Factor / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D016207:Cytokines; D037102:Lectins; D050799:STAT5 Transcription Factor; D048051:p38 Mitogen-Activated Protein Kinases; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human