Important: This site is no longer maintained! For the latest updates, please visit http://blog.crohn.ie

Title: Nucleotide sequence analysis and seroreactivities of the 65K heat shock protein from Mycobacterium paratuberculosis.
Title Abreviation: Clin Diagn Lab Immunol Date of Pub: 1995 Nov
Author:
Issue/Part/Supplement: 6 Volume Issue: 2 Pagination: 657-64
MESH Headings: Animal; Antibodies, Bacterial (IM); Base Sequence; Cattle; Cloning, Molecular; Crohn Disease (IM/MI); Genes, Bacterial (GE); Goats; Heat-Shock Proteins (*GE/*IM); Human; Molecular Sequence Data; Mycobacterium paratuberculosis (*GE/*IM); Paratuberculosis (IM/MI); Rabbits; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sheep; Support, Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.; -RN-;
Journal Title Code: CB7 Publication Type: JOURNAL ARTICLE
Date of Entry: 960312NEntry Month: 9605
Country: UNITED STATES Index Priority: 2
Language: Eng Unique Identifier: 96157365
Unique Identifier: 96157365 ISSN: 1071-412X
Abstract: Mycobacterium paratuberculosis is the causative agent of Johne's disease, a chronic enteritis in ruminants. It has also been implicated as a possible cause of Crohn's disease, an inflammatory bowel disease of unknown etiology. The mycobacterial 65K heat shock proteins (hsp-65K) are among the most extensively studied mycobacterial proteins, and their immunogenic characteristics have been suggested to be the basis for autoimmunization in chronic inflammatory diseases. In this context, we isolated and sequenced the hsp-65K-encoding gene from our M. paratuberculosis PTB65K genomic library. A high degree of identity was found between the open reading frame (ORF) of the PTB65K gene and those of Mycobacterium tuberculosis (89.6%), Mycobacterium leprae (86.6%), and Mycobacterium avium 18 (98.8%). The amino acid sequence alignment of the PTB65K protein with the hsp-65K homologs revealed that the M. tuberculosis and M. leprae proteins each differed by 36 amino acid residues and that the M. avium 18 protein differed by 8 residues. We also investigated the humoral immune responses of animals with Johne's disease and patients with Crohn's disease against the recombinant PTB65K antigen. Immunoblot analysis showed that sera from only 3 of 10 clinically ill and 5 of 25 subclinically ill cows reacted with PTB65K. In addition, sera from two of two sheep and one of two goats with clinical symptoms of Johne's disease also reacted with PTB65K; 0 samples from 10 normal cows reacted. In humans, sera from 7 of 13 patients with Crohn's disease, 3 of 4 with tuberculosis, 5 of 6 with leprosy, 5 of 12 with non-inflammatory bowel disease, and 0 of 4 with ulcerative colitis reacted with the recombinant PTB65K antigen. These results indicate that this PTB65K heat shock protein is uninformative when used for serodiagnosis of Johne's disease in animals. However, in humans, the high intensity of antibody reactions of some sera from Crohn's disease patients compared with that from noninflammatory bowel disease patients showed a positive correlation with mycobacterial diseases.
Abstract By: Author
Address: Inflammatory Bowel Disease Laboratory, Veterans Affairs Medical Center, Houston, TX 77030, USA.