Caraş Iuliana, Tucureanu Cătălin, Pitica Ramona, Sălăgeanu Aurora
Infection and Immunity Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania.
Roum Arch Microbiol Immunol. 2011 Jan-Mar;70(1):28-36.
CANTASTIM is a second generation bacterial immunomodulator. The aim of this study was to examine the mechanism by which bacterial immunomodulator CANTASTIM induces production of inflammatory cytokines in monocytes/macrophages. Proinflammatory cytokines were induced in PMA-differentiated THP-1 cells by stimulation with TLR agonists and CANTASTIM in the presence or absence of anti-TLR blocking antibodies or isotype matched control antibodies. Also, RNA interference was used to knockdown TLR2 or TLR4 expression in PMA-differentiated THP-1 cells before stimulation. As expected, induction of TNF-alpha and IL-6 by TLR4 agonist LPS was inhibited in a significant manner by anti-TLR4 but not by anti-TLR2 antibody. Unexpectedly, treatment with anti-LR2 blocking antibody inhibited only IL-6 production induced by Pam3CSK4 while the level of TNF-alpha was unchanged. When cells were stimulated by TLR2 agonist heat-killed Listeria monocytogenes the release of TNF-alpha was significantly attenuated by anti-TLR2 antibodies. Silencing of TLR2 led to a statistically significant inhibition of TNF-alpha secretion induced by TLR2 agonist while siRNA silencing of TLR4 did not affect the response to TLR2 agonist. Cells exposed to CANTASTIM produced significant levels of pro-inflammatory cytokines but the levels were lower than LPS-stimulated cells. Production of both cytokines was inhibited by treatment with anti-TLR2 blocking antibody and not by anti-TLR4 antibody. Silencing of TLR2 led to a statistically significant inhibition of TNF-a secretion induced by CANTASTIM while silencing of TLR4 had no effect on the response to CANTASTIM. These results support the hypothesis that CANTASTIM may exert its immunomodulatory and adjuvant activities through interaction of its bacterial components with TLR2.
CANTASTIM是一种第二代细菌免疫调节剂。本研究的目的是探讨细菌免疫调节剂CANTASTIM诱导单核细胞/巨噬细胞产生炎性细胞因子的机制。在存在或不存在抗TLR阻断抗体或同型匹配对照抗体的情况下，通过用TLR激动剂和CANTASTIM刺激，在PMA分化的THP-1细胞中诱导促炎细胞因子。此外，在刺激前，使用RNA干扰敲低PMA分化的THP-1细胞中TLR2或TLR4的表达。如预期的那样，抗TLR4抗体以显著方式抑制了TLR4激动剂LPS诱导的TNF-α和IL-6的产生，但抗TLR2抗体没有。出乎意料的是，用抗LR2阻断抗体处理仅抑制了Pam3CSK4诱导的IL-6产生，而TNF-α水平未改变。当细胞用TLR2激动剂热灭活的单核细胞增生李斯特菌刺激时，抗TLR2抗体显著减弱了TNF-α的释放。TLR2的沉默导致由TLR2激动剂诱导的TNF-α分泌受到统计学上显著的抑制，而TLR4的siRNA沉默不影响对TLR2激动剂的反应。暴露于CANTASTIM的细胞产生了显著水平的促炎细胞因子，但水平低于LPS刺激的细胞。两种细胞因子的产生均被抗TLR2阻断抗体处理所抑制，而抗TLR4抗体则没有。TLR2的沉默导致由CANTASTIM诱导的TNF-α分泌受到统计学上显著的抑制，而TLR4的沉默对CANTASTIM的反应没有影响。这些结果支持以下假设：CANTASTIM可能通过其细菌成分与TLR2的相互作用发挥其免疫调节和佐剂活性。
