Investigating Associations between HLA-DR Genotype, H. pylori Infection, and Anti-CagA IgA Seropositivity in a Turkish Gastritis Cohort.
Genes (Basel)
; 15(3)2024 03 06.
Article
in En
| MEDLINE
| ID: mdl-38540398
ABSTRACT
Helicobacter pylori (H. pylori) is associated with gastric inflammation and mucosal antibodies against its cytotoxin-associated gene A (CagA) are protective. Vaccine-elicited immunity against H. pylori requires MHC class II expression, indicating that CD4+ T cells are protective. We hypothesized that the HLA-DR genotypes in human populations include protective alleles that more effectively bind immunogenic CagA peptide fragments and susceptible alleles with an impaired capacity to present CagA peptides. We recruited patients (n = 170) admitted for gastroendoscopy procedures and performed high-resolution HLA-DRB1 typing. Serum anti-CagA IgA levels were analyzed by ELISA (23.2% positive) and H. pylori classified as positive or negative in gastric mucosal tissue slides (72.9% positive). Pearson Chi-square analysis revealed that H. pylori infection was significantly increased in DRB1*1104-positive individuals (p = 0.027). Anti-CagA IgA was significantly decreased in DRB1*1104 positive individuals (p = 0.041). In contrast, anti-CagA IgA was significantly increased in DRB1*0301 positive individuals (p = 0.030). For these HLA-DRB1 alleles of interest, we utilized two in silico prediction methods to compare their capacity to present CagA peptides. Both methods predicted increased numbers of peptides for DRB1*0301 than DRB1*1104. In addition, both alleles preferred distinctively different CagA 15mer peptide sequences for high affinity binding. These observations suggest that DRB1*1104 is a susceptible genotype with impaired CagA immunity, whereas DRB1*0301 is a protective genotype that promotes enhanced CagA immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Helicobacter pylori
/
Gastritis
Limits:
Humans
Language:
En
Journal:
Genes (Basel)
Year:
2024
Document type:
Article
Affiliation country:
Turquía