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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS. Meshes: Alleles, Amino Acid Sequence, Antigens, Bacterial, Bacterial Proteins, CD4-Positive T-Lymphocytes, Catalase, Cell Separation, Cells, Cultured, Flow Cytometry, Genetic Association Studies, Genetic Predisposition to Disease, HLA-DR Antigens, HLA-DRB1 Chains, Histocompatibility Testing, Host-Pathogen Interactions, Humans, Interferon-gamma, Latent Tuberculosis, Lymphocyte Activation, Molecular Sequence Data, Mycobacterium, Sarcoidosis, Pulmonary, United States.
user
Are mycobacterial ESAT-6 and katG recognized by sarcoidosis CD4+ T cells when presented by the American sarcoidosis susceptibility allele , DRB1*1101? Context: Genetic associations of American sarcoidosis susceptibility implicate MHC class II allele, DRB1*1101. We previously reported immune recognition of Mycobacterium peptides from peripheral cells of 26 sarcoidosis subjects, 24 PPD- healthy volunteers, and eight with latent tuberculosis infection. In order to further link these genetic and immunologic pillars of sarcoidosis pathogenesis, we performed flow cytometry on these same subjects to identify the cells responsible for immune responses to ESAT-6 and katG peptides, followed by HLA typing to determine allelic associations with recognition.
assistant
Sarcoidosis CD4+ T cells were primarily responsible for the systemic responses. Recognition was inhibited by monoclonal antibody against HLA-DR and HLA-DQ, but not HLA-DP. Immune recognition of ESAT-6 peptide NNALQNLARTISEAG was associated with possession of DRB1*1101. ESAT-6 and katG presented by antigen-presenting cells expressing DRB1*1101-induced Th-1 responses from sarcoidosis T cells, thus providing a mechanistic insight for the association of HLA DRB1*1101 with sarcoidosis, and sarcoidosis T cell interaction with microbial antigens. Final Decision: yes