Signal pathway defects of Toll-like receptors 2-p38 mitogen activated protein kinase signal pathway defects and immune suppression in children with measles / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the expression of Toll-like receptors 2 (TLR2) mRNA,p38 mitogen activated protein kinase(p38 MAPK) mRNA and cytokine in peripheral blood of children with measles and to study the effect and possible mechanism for TLR2-p38 MAPK signal pathway defects on immune suppression in the children with measles during acute phase.Methods Thirty children with measles hospitalized in the department of infectious diseases from June 2012 to July 2013 were enrolled into the measles group,and 30 healthy children were chosen as the healthy control group.The mRNA expressions of TLR and p38 MAPK in peripheral blood mononuclear cells (PBMC) were detected by reverse transcription-polymerase chain reaction (RT-PCR).The protein levels of interferon-γ (IFN-γ),tumor necrosis factor-β (TNF-β),interleukin (IL)-12,IL-6 and IL-10 in plasma were measured by using enzyme linked immunosorbent assay (ELISA),and flow cytometry (FCM)was applied to detect the percentage of lymphocyte subpopulation.The serum IgG,IgA and IgM levels were detected by velocity scatter turbidimetry.Results (1) The expressions of TLR2 mRNA and p38 MAPK mRNA in the measles group were both significantly lower than those in the healthy control group (all P ＜ 0.05).(2) Compared with the healthy control group,the protein levels of IFN-γ,TNF-β and IL-12 in the plasma of the measles group decreased significantly (all P ＜ 0.05),and the levels of IL-6 and IL-10 increased significantly(all P ＜ 0.05).(3)Compared with the healthy control group,the percentage of CD3 +,CD4 +,CD4 +/CD8 + ratio and the level of IgG and IgA in the measles group decreased significantly(all P ＜ 0.05),and the percentage of CD19 + increased significantly(P ＜ 0.05),but there was no any significant change in the percentage of CD8 + and the level of IgM (all P ＞ 0.05).Conclusions The mRNA expressions of TLR2 and p38 MAPK are low in PBMC in the measles children during acute phase.There are different degrees of suppression of cell immunity,humoral immune and cytokines disorder in children with measles.Defects of TLR2-p38 MAPK signal pathway may cause the formation of measles immune suppression.