1. Human MOSPD2: A bacterial Lmb mimicked auto-antigen is involved in immune infertility
- Author
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Rajeshwari Parida
- Subjects
lcsh:Immunologic diseases. Allergy ,Antigenicity ,Immunogen ,Research paper ,Auto-antibody ,Immunology ,LCS, Leukocytospermia ,Semen ,Immunoelectrophoresis ,Biology ,Immune system ,BS, Bacteriospermia ,medicine ,Immunology and Allergy ,Motile sperm domain-containing protein 2 ,medicine.diagnostic_test ,Autoantibody ,RIEP, Rocket Immunoelectrophoresis ,Sperm ,Molecular biology ,Immune infertility ,Laminin binding protein ,biology.protein ,Auto-antigen ,Lmb, Laminin binding protein ,Antibody ,lcsh:RC581-607 ,MOSPD2, Motile sperm domain-containing protein 2 ,TLR, Toll-like receptor - Abstract
Autoantibody production is one of the leading factors of immune infertility, an autoimmune disease of the male reproductive system. The potential involvement of MHC-class II derived self-peptides against bacterial proteins in the antisperm antibody (ASA) production has been reported previously. Apparently, Streptococcus agalactiae has been considered as an important pathogen to impart infection-induced infertility in a bacteriospermia associated leukocytospermia (LCS/BS) state. Hence, the present study attempts to confirm S. agalactiae specific Laminin binding protein (Lmb) derived self-peptide (‘KDSYTKKAKAFKKEA’) namely human Motile Sperm domain-containing protein 2 (MOSPD2) as an auto-antigen in LCS/BS condition. Semen samples were collected from infertile men with LCS/BS (n = 17) and their fertile counterparts (n = 10). Gram-positive bacteria were predominantly identified in the entire 17 LCS samples using culture method followed by 16S rDNA sequencing technique. TLRs 2 and 4 expression used as markers of immune response in spermatozoa and sperm dysfunction were elevated in the LCS/BS spermatozoa as compared to their fertile counterparts. A significant increase in oxidative stress indices i.e., protein carbonylation, lipid peroxidation and acridine orange test (AOT), was also observed in the LCS/BS spermatozoa. Spermatozoa lysate (both auto and heterologous), bacterial lysate (control) and synthesized MOSPD2 self-peptide were used to test their antigenicity against the autoantibodies by rocket immunoelectrophoresis (RIEP) assay. Seminal plasma from LCS/BS patients with S. agalactiae was used as the source of autoantibodies. Spermatozoa and bacteria lysate; and MOSPD2 self-peptide were able to bind autoantibodies in the seminal plasma. Besides, the self-peptide showed a dose dependent increase in the precipitation of antibody. T-cell epitope mapping of 48 Enterococcus faecalis and 91Staphylococcus aureus surface proteins confirmed MOSPD2 as a global auto-antigen. Thus, augmentation of TLR expression in LCS/BS spermatozoa inferred MOSPD2 to be a putative immunogen. Altogether, these findings will delineate the significance of MOSPD2 auto-antigen in a bacteria derived immune infertility condition., Graphical abstract Image 1, Highlights • Autoantibodies produced in the seminal plasma bind to bacteria and sperm antigens. • Lmb mimicked MOSPD2 self-peptide is a bacteria as well as, sperm antigen. • MOSPD2 is a global auto-antigen.
- Published
- 2019