Study on the expression of TLR2 and TLR4 in peripheral blood mononuclear cells and their relation- ship with Th1/Th2 immune response in patients with Henoch-Schonlein purpura / 中华微生物学和免疫学杂志

ABSTRACT

Objective To explore the role of TLR2 and TLR4 in the pathogenesis of Henoch-Schonlein purpura ( HSP) by investigating their expression at mRNA and protein levels in peripheral blood mononuclear cells ( PBMCs ) and their influences on Th 1/Th2 immune response in children with HSP . Methods 64 hospitalized children with HSP in the Affiliated Hospital of Qingdao University Medical Col -lege from October 2011 to November 2012 were enrolled in the study .They were further divided into non-He-noch-Schonlein purpura nephritis ( NHSPN ) group ( n =36 ) and Henoch-Schonlein purpura nephritis (HSPN) group (n=28).30 age-matched healthy children from Child Health Division of the same hospital were selected as controls .The expression of TLR2 and TLR4 at mRNA level in PBMCs were detected by re-al-time fluorescent polymerase chain reaction .The expression of TLR2 and TLR4 at protein level and T cells subset were detected by flow cytometry .The levels of IFN-γ, IL-4 and IL-6 in plasma were determined by enzyme-linked immunosorbent assay (ELISA).Results (1)Compared with the control group , the expres-sion of TLR2 and TLR4 at mRNA and protein levels were remarkably increased in children with HSP , espe-cially in HSPN group.(2)Compared with the control group, the percentage of CD3+T cells and CD3+CD4+T cells were down-regulated in HSP group , but the percentage of CD 3+CD8+T cells and CD3+HLADR+T cells were up-regulated.(3)The level of IFN-γand the ratio of IFN-γ/IL-4 in plasma from children with HSP were significantly lower than those of the controls , while the level of IL-4 and IL-6 were remarkably higher than those of the controls .(4)The expression of TLR2 and TLR4 at protein level in PBMCs from chil-dren with HSP showed significant positive correlations with the expression of TLR 2 and TLR4 at mRNA level and plasma concentration of IL-4 and IL-6, but a negative correlation with the ratio of IFN-γ/IL-4.Conclu-sions The aberrant activation of TLR 2 and TLR4 might be correlated with the immunological pathogenesis of HSP by enhancing Th2 immune response.The hyper-activation of TLR2 and TLR4 might result in renal injury in patients with HSP .