The variation of CD4+ memory T cells in the development of asthma in mice (P6233)

Abstract

Abstract Objective To understand the role of CD4+ memory T cells in pathogenesis of asthma in mice Method Female BALB/c mice were sensitized and challenged with OVA for continuous 7 days. After one month, another challenge was given for one day. We detected the ratio changes of CD4+ memory T cells in CD4+ T cells during the treatment course, the membrane surface markers of CD3+, CD4+, CD44High, CD62L- were examined by using a flow cytometry. We further compared the different challenge time durations effect on CD4+ memory T cell numbers. Results In control mice, the ratios of CD4+ memory T cells in lung and spleen were 11.32% and 20.48%, respectively; After challenge, the ratio of CD4+ memory T cells increased gradually and reached the peak value ( 53% in lung and 45% in spleen) at one week after the last challenge. After one month these ratios returned to the levels of before the challenge. However, these memory T cells raised up rapidly on the next day during the second challenge, especially in the lung and kept relatively stable levels (about 35% in lung and 30% in spleen) within one week. We observed that the different challenge time durations had similar effect on the ratio of CD4+ memory T cells in lung, but it differ in spleen the peak value of CD4+ memory T cells at 30min challenge was 10% lower than that with 1 hour challenge and dropped earlier. Conclusion The CD4+ memory T cells play important roles in asthma pathogenesis, the detailed mechanisms warrant further exploration.