Characterization of CD4+ T cell after immunization with H1N1 influenza vaccine for children

Abstract

Objective To explore the characteristics of CD4+ memory T cell in children with influenza A (H1N1) vaccination. Methods According to the voluntary principle, 31 children with influenza A (H1N1) vaccination for over 47 months were selected.Their lymphocytes were isolated and joined with the influenza A (H1N1) vaccine for cultivation, which was taken as the experimental group, and the control group was treated with no vaccine.The flow cytometry was used to detect the expression of cell surface molecules. Results The results showed that the proportion of CD4+ T cells in PBMC was 29.85% in the experimental group and 39.00% in the control group; the proportion in the experimental group was lower than that in the control group.The proportions of CD4+ naive T cells in the experimental group and in the control group were both more than 70% (P>0.05); the proportion of CD4+ memory T cells in the experimental group was 28.54% and 25.52% in the control group(P>0.05). Memory T cells were divided into central and effector memory T cells.Detection results of two subsets: The proportions of CCR7 and CD62L single positive memory T cell subsets in the experimental group were 72.52% and 29.85%, respectively, their proportions in the control group were 84.0% and 93.44%; the proportions in the experimental group were significantly lower than those in the control group (P<0.05). Conclusion This study shows that CD4+ T cells are dominant cells in 31 children, and the proportion of naive T cells (CD45RA+ ) is high.H1N1 influenza vaccine can induce production of antigen-specific memory CD4+ T cells, but few in number; wherein, most of them are central memory CD4+ T cells, furthermore, the numbers of CCR7 and CD62L single positive memory T cells are small. Key words: Children; H1N1 influenza vaccine; Memory T cell; Immune memory