title: Autolytic Mycobacterium leprae Hsp65 fragments may act as biological markers for autoimmune diseases.
abstract: Investigating the proteolytic activity of the recombinant Mycobacterium leprae Heat Shock Protein of 65 kDa (rHsp65), chaperonin 2 (cpn2), we observed that it displays high instability. The fragmentation process starts at the C-terminus followed by progressive degradation of the N-terminus, which leads to a stable fragment comprising the middle region of the molecule. Urea was able to prevent autolysis, probably due to its denaturing action, while EDTA increased degradation levels indicating the need for metal ions. Peptides originated from autolysis were purified and analyzed by mass spectrometry, generating a continuous map. Since the bacteria and mammalian Hsp60 are known to be targets of the immune response and have been implicated in autoimmune diseases and chronic inflammation, the in vivo effect of rHsp65 peptides was evaluated in the spontaneous Systemic Lupus Erythematosus (SLE) model developed by the (NZB/NZW)F(1) mouse hybrids, and their individual anti-rHsp65 IgG2a/IgG1 antibody titer ratio was determined. The results showed orientation toward a T(H)1 responsiveness, and the treatment with the rHsp65 peptides diminished the environmental variance of the survival time of treated animals. These results outline the fact that environmental factors may also act through the modified stability expression of Heat Shock Proteins intervening during autoimmune processes.
authors.affiliation: Center for Applied Toxinology (CAT-CEPID), Butantan Institute, Av. Vital Brazil 1500, Butantan, CEP 05503-900, São Paulo, São Paulo, Brazil.
authors.forename: Carolina Angélica
authors.initials: CA
authors.lastname: Parada
authors.forename: Fernanda
authors.initials: F
authors.lastname: Portaro
authors.forename: Eliana Blini
authors.initials: EB
authors.lastname: Marengo
authors.forename: Clécio Fernando
authors.initials: CF
authors.lastname: Klitzke
authors.forename: Elisabete José
authors.initials: EJ
authors.lastname: Vicente
authors.forename: Marcella
authors.initials: M
authors.lastname: Faria
authors.forename: Osvaldo Augusto
authors.initials: OA
authors.lastname: Sant'Anna
authors.forename: Beatriz Lieblich
authors.initials: BL
authors.lastname: Fernandes
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis*; D001426:Bacterial Proteins / Q000276:immunology*; D015415:Biomarkers / Q000097:blood*; D018834:Chaperonin 60 / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D009166:Mycobacterium leprae / Q000276:immunology*; D012376:Rodent Diseases / Q000276:immunology; D016019:Survival Analysis
chemical_list: D001323:Autoantibodies; D001426:Bacterial Proteins; D015415:Biomarkers; D018834:Chaperonin 60; C074119:heat-shock protein 65, Mycobacterium