Department of Animal Science and Technology, Konkuk University , Seoul, Republic of Korea.
Speegenebio, Co., Ltd , Seongnam, Republic of Korea.
Bioengineered. 2021 Dec;12(1):461-475. doi: 10.1080/21655979.2021.1875664.
invariant natural killer T (iNKT) cells have been reported to regulate a diverse set of immunological responses. iNKT cell dysfunction in cytokine secretion is linked to the development of autoimmunity, an immune response against its own tissue. Interestingly, CD4 iNKT cells preferentially secrete regulatory cytokines. Here we investigated what kind of secreting factors of it are involved in dendritic cell (DC) maturation to regulate immune responses. We found one of them, prolactin induced protein (PIP), from the supernatants of cultured CD4 iNKT cells. It was validated using RT-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analysis. Subsequent analysis upon PIP treatment was performed using fluorescence-activated cell sorting (FACS) analysis. We identified PIP as one of strong candidates for inducing DC maturation, to similar level to lipopolysaccharide, an already known candidate molecule. Recombinant PIP recapitulated natural function, and induction of DC differentiation by both recombinant and purified PIP was blocked by anti-Toll-like receptor (TLR)2 antibody (Ab), but not by anti-TLR4/5 or anti-receptor Ab for advanced glycation end product Ab. Interestingly, PIP induced the differentiation of naïve T cells into CD4 CD25 Foxp3 regulatory T cells and reduced the number of helper T (Th)1 and Th17 cells produced by Pam3CysSerLys4. Take in together, these results suggest that PIP is an important factor that mediates immunoregulation by iNKT cells through TLR2-mediated signaling.
天然不变自然杀伤 T(iNKT)细胞已被报道可调节多种免疫反应。iNKT 细胞在细胞因子分泌方面的功能障碍与自身免疫的发展有关，即针对自身组织的免疫反应。有趣的是，CD4+iNKT 细胞优先分泌调节性细胞因子。在这里，我们研究了它分泌的哪种因子参与树突状细胞(DC)成熟来调节免疫反应。我们从培养的 CD4+iNKT 细胞的上清液中发现了一种因子，即催乳素诱导蛋白(PIP)。使用 RT-定量实时聚合酶链反应(RT-qPCR)和 Western blot 分析验证了这一点。随后使用荧光激活细胞分选(FACS)分析对 PIP 处理后的结果进行了分析。我们确定 PIP 是诱导 DC 成熟的强有力候选因子之一，与脂多糖(LPS)的作用相似，LPS 是一种已知的候选分子。重组 PIP 再现了天然功能，并且通过重组和纯化的 PIP 诱导的 DC 分化被抗 Toll 样受体(TLR)2 抗体(Ab)阻断，但不能被抗 TLR4/5 或晚期糖基化终产物 Ab 的受体 Ab 阻断。有趣的是，PIP 诱导幼稚 T 细胞分化为 CD4+CD25+Foxp3 调节性 T 细胞，并减少 Pam3CysSerLys4 产生的辅助性 T(Th)1 和 Th17 细胞的数量。综上所述，这些结果表明，PIP 是 iNKT 细胞通过 TLR2 介导的信号转导介导免疫调节的重要因子。
