Expression of Toll-like receptor 2 and 9, myeloid cell differentiation 88 and Thl/Th2 cytokines in spleen lymphocytes of early cytomegalovirus infected newborn murine / 中华围产医学杂志

ABSTRACT

Objective To investigate the alteration of Toll-like receptor (TLR) 2 and 9,myeloid cell differentiation 88 (MyD8),interleukin-2 (IL 2),interferon-γ(IFN γ) and interleukin-10 (IL-10) expression in spleen lymphocytes of cytomegalovirus (CMV) infected newborn murine.Methods Sixty-four neonatal mice were randomly divided into control group and CMV infected group (32 mice in each).Mice in CMV infected group were injected intraperitoneally with 20 μl CMV suspension (tissue culture infections dose 50 of 104.31 U/0.1 ml) at 4 6 hours after birth to create the systematic CMV infection models.At 3,5,7 and 10 days old,eight mice randomly selected from each group were sacrificed.Polymerase chain reaction was applied to detect CMV-DNA in liver,spleen,heart,lung,kidney and salivary glands of 7 day old mice.Western blot was used to measure the protein expression of T1R 2,9 and MyD88 in spleen lymphocyte,and enzyme linked immunosorbent assay was used to test the levels of IL-2,IFN-γand IL-10 in supernatant of spleen lymphocyte from 3,5,7 and 10-dayold mice.Independent samples t test and Pearson correlation analysis were applied as the statistical methods.Results On the 7th day after CMV infection,the protein expression of TLR 2,9 and MyD88 in spleen lymphocyte in CMV infected group increased to the maximum level (1.06±0.09,1.19±0.03 and 0.89±0.07),which were higher than those in control group (0.47±0.04,0.71 ±0.02 and 0.43±0.03),the differences were statistically significant(t=21.69,50.40 and 42.06,P＜0.01,respectively).In CMV infected group,expression of IL-2 decreased to the lowest level on the 7th day after CMV infection [(16.9±7.3) pg/ml],IFN γ reached its peak level on the 5th day [(242.9±8.4) pg/ml] and IL-10 increased since the 5th day [(62.4±11.1) pg/ml],there were statistically significant differences as compared with control group [(51.9± 10.8) pg/ml,(135.3±10.5) pg/ml and (36.3±5.1) pg/ml](t=15.74,19.00 and 9.60,P＜0.05,respectively).There was a negative correlation between TLR2,TLR9,MyD88 protein expression and IL-2 level (r =0.978,0.960 and-0.979,all P＜0.01,respectively) and a positive correlation between TLR2,TLR9,MyD88 protein and IL-10 level (r =0.954,0.914 and 0.892,P ＜ 0.01,respectively).Conclusions In the early phase of CMV infection (within 7 days),immunity is activated through TLR/MyD88 signal pathway resulting anti-infection effect.However,after the 7th day,Th1/Th2 cellular immunity imbalance allows virus to replicate easily.