In silico study of the possible role of Acinetobacter baumannii infection in triggering autoimmune diseases

Almost all autoimmune diseases (AD) have been associated with at least one infection. Multidrug-resistant Acinetobacter baumannii is classified by the WHO and CDC as a critical-priority pathogen. In this study, the proteome of A. baumannii ATCC۱۹۰۶ was investigated regarding the potential to cause AD. First, the protein sequences of A. baumannii were subjected to NCBI BLASTp with an E-value threshold of ≤ ۱×۱۰⁻⁶ against the Homo sapiens proteome to find sequences with ≥۹ amino acid similarities. Then, the association of human proteins that possessed similar bacterial peptides, in the development of ADs was evaluated by the Autoimmune Disease Association Database (GAAD). Next, peptides of AD-associated proteins were checked for their ability to bind to MHCI and MHCII molecules, and the population coverage of alleles binding to potent peptides was extracted. The results indicated that ninety-four proteins from this bacterium had identical peptide sequences with ۹۵۷ human AD-related proteins. Among ۲۱۳ peptides, ۱۲ peptide sequences have the possibility of strong binding with MHCI (%Rank < ۰.۵), and ۱۳ peptide sequences have the possibility of strong binding with MHCII (%Rank < ۲). CEAHLGHVF and QIQGFFDIPVDN established the strongest connections with MHCI and MHCII. YVGAGTVEF peptide could also bind to both MHC classes. Regarding the peptides binding the alleles with the highest population coverages, GAEPLFFLDY (world coverage of ۱۷.۳۴%) and LPGAGGTQRL (world coverage of ۱۲.۷۸%) were the top MHCI and MHCII binding peptides. These findings suggest candidate peptides that meet the first checkpoint of molecular mimicry, warranting experimental evaluation for potential links to immune-mediated and autoimmune conditions, including Parkinson's disease, Vitiligo, Inflammatory bowel disease, Systemic lupus erythematosus, Rheumatoid arthritis, Multiple sclerosis, Antiphospholipid syndrome, and IgA nephropathy.

کلیدواژه ها:

Acinetobacter baumannii ، In silico ، Major histocompatibility complex ، Autoimmune diseases