Relation of Regulatory Foxp3+ T Cells with Helicobacter pylori and Its Virulence Genes

The study aimed to assess the tangled relation between various CD25 subsets (positive, negative and high) of CD4+ FoxP3+ T cells and H. pylori including its virulence genes (CagA and VacA). Diagnosis of H. pylori and its virulence genes was based on a positive culture, histopathology and/or CLO-test and PCR. Flow cytometry was used toquantifyTregs.CD4+CD25high Foxp3+ T cells were higher in patients than controls and somewhat more in H. pylori positive than negative patients. CD4+CD25high Foxp3+ T cells secreting IL10 were lower in H. pylori positive patients.CD4+CD25-Fox3+T cells were also higher in patients than controls and more in those negative for H. pylori. Moderate negative correlation was found between the presence of CagA or VacA sm genotypes and Tregs secreting IL10. CD4+CD25- Foxp3+ T cells, especially those secreting IL10, tend to be higher in patients carrying VacA m1 allele than m2 allele. In conclusion, H. pylori stimulate a regulatory T cell response, probably contributing to gastric diseases. CD25 negative subset of Fox3+CD4+T cells needs further studying to declare its potential role in immunopathogenesis of gastric diseases. Tregs are positively associated with vacA alleles.