Study On The Phenotypic Characterization Of Naive And Memory T Cell After Immunization With H1n1Influenza Vaccine For Children

Objective: Study on the phenotypic characterization of naive and memory T cell inH1N1influenza vaccine for children, in order to provide theoretical guidance forevaluating of long-term effect of the H1N1influenza vaccine and developing newvaccines and vaccination strategies.Methods:（1）Based on parents’ volunteer, we chose31cases as the objects of ourstudy. The objects are those children aged from3to6years old who had acceptedH1N1influenza vaccine in Shenzhen longgang maternal and child health hospitalduring December2009to January2010.（2）The lymphocytes isolated from3ml peripheral Venous blood were joined withthe H1N1influenza vaccine as experimental group and cultured in5%CO2at37°Cincubator for50hours. The experiment set without vaccine group as control group.At last we detected the surface molecules: CD4/CD8, CD45RA, CD45RO, CD62L,CCR7by FCM.（3）Both experimental group and control groupcultured in5%CO2at37°Cincubator for50hours. The CCK-8assay was added to detecting cellular proliferationand cellular proliferation index were detected by CCK-8.Results:（1）CD4+T cells are the dominant proportion in PBMC which is composedof CD4+T cells and CD8+T cells，P <0.05. The proportion of CD4+T cells inexperimental group reaches29.85%which is lower than the proportion(39%) incontrol group, P <0.05. The proportion of CD8+T cells have no significant differencebetween two groups, P>0.05. （2）CD4+CD45RA+naive T cells in the two groups are up to more than70%, P>0.05. According to the antibody level in three groups were compared. The results ofCD4+CD45RA+cells between the three groups have no statistical significant, P>0.05. The data of CD8+CD45RA+is similar.（3）The proportion of CD4+CD45RO+memory T cells in experimental group is25.52%and the proportion in control group is28.54%, which have no statisticalsignificance, P>0.05. According to the antibody level in three groups were compared,the results of CD4+CD45RO+cells have no statistical significant, P>0.05.（4）Two subsets of CD4+CD45RO+memory T cells: CCR7+and CD62L+singlepositive memory T cell subsets in the experimental group are significantly lower thanthat of the control group, P <0.05.（5）CD8+CD45RA+naive T cells in the two groups was up to more than80%, P>0.05; According to the antibody level in three groups were compared, the results ofCD8+CD45RA+cells have no statistical significant, P>0.05.（6）CD8+CD45RO+memory T cells in the two groups are up to17-19%, P>0.05;According to the antibody level in three groups were compared, the comparison haveno statistical significant, P>0.05.（7）Two subsets of CD8+CD45RO+memory T cells: CCR7and CD62L singlepositive memory T cell subsets in the experimental group are significantly lower thanthat of the control group, P>0.05.（8）The CCK-8assay was added to detect cellular proliferation. Only51.16%ofwhich cellular proliferation index was greater than0.8, with none was greater than1in this study.Conclusion:（1）This study showed that in31cases of children the CD4+T cellswere the dominant cells, naive T cells(CD45RA+)were higher, with antigenstimulation and response. But the naive T cell in the experimental group was low,which indicated that the base of the vaccine immune memory was poor. （2）In this study, CD4+memory T cells was the main phenotypic characteristics inthe31cases of children. The data of antigen specific memory T cells suggested thatH1N1vaccination specific memory T cells were few in number，and without specificsecondary response after more than3years.（3）In this study,31cases of children’s memory T cell subsets were diversity, centralmemory cells was the main phenotypic characteristics. Cellular proliferation indexshowed that the proliferation of specific cells vaccine was poor.