Despite the availability of an effective vaccine and antiviral treatments, hepatitis B is still a global public health problem. Hepatitis B vaccination can prevent the disease. Vaccination induces long-lasting protective immune memory, and the identification of memory cell subsets can indicate the effectiveness of vaccines. Here, we compared the frequency of CD4^{+} memory T cell subsets between responders and nonresponders to HB vaccination. Besides, the frequency of IFN-γ^{+} memory T cells was compared between studied groups. Study participants were grouped according to their anti-HBsAb titer. For restimulation of CD4^{+} memory T cells, peripheral blood mononuclear cells (PBMCs) were cultured in the presence of HBsAg and PHA for 48 h. Besides, PMA, ionomycin, and brefeldin were added during the last 5 h of incubation to induce IFN-γ production. Flow cytometry was used for analysis. There was a statistically significant difference in the frequency of CD4^{+}CD95^{+}, CD4^{+}CD95^{Hi}, and CD4^{+}CD95^{low/med} T stem cell memory (T_{SCM}) cells between responder and nonresponder groups. However, the comparison of the frequency of memory T cells producing IFN-γ showed no differences. Our results identified a possible defect of immunological CD4^{+} memory T cell formation in nonresponders due to their lower frequency of CD4^{+} T_{SCM} cells.
【저자키워드】 hepatitis B vaccine, CD4+ memory T cells, Memory T cells producing IFN-γ, T central memory, T effector memory, T stem cell memory.,