CD14-dependent and independent pathways in B cells activation after stimulation with lipopolysaccharides from periodontopathic bacteria

在这项研究中，我们评估了CD 14在B细胞活化后的牙周病细菌的脂多糖刺激的可能作用。然后，我们研究了LPS诱导的信号转导机制，介导后来的细胞反应的B细胞。结果表明，CD 14不仅存在于髓系细胞中，还参与了LPS诱导的细胞活化和向IgA产生型B细胞的分化，使CDK表达增强，TGF-β产生增加，并诱导产生不同于IgA产生型B细胞的同种型。然而，在LPS诱导的B细胞活化中也可能存在CD 14非依赖性途径，最终导致增殖、IL-6产生和IgM（而不是伊加）分泌的增强。还表明，来自牙龈卟啉单胞菌以及其他牙周病细菌、中间普氏菌、伴放线放线杆菌和腐蚀艾肯菌的LPS的触发信号可以通过酪氨酸和苏氨酸磷酸化途径转导，并诱导B细胞的活化，最终导致增殖。综上所述，本研究结果表明，牙周病细菌的LPS具有通过CD 14依赖性和非依赖性活化途径诱导B细胞刺激的有效性质，其中增加的酪氨酸和苏氨酸磷酸化可能是导致细胞应答的重要信号事件。

In this study we assessed the possible role of CD14 in B cells activation after stimulation with lipopolusaccharides from periodontopathic bacteria. We then examined the LPS-induced signal transduction mechanism that mediates later cellular responses of B cells. The results indicated that CD14 not restricted to myeloid dells, and was involved in some cellular activations and the isotype differentation to IgA-producing B cell to the enhanced expression of CDK TGF-β- production and the isotype different to IgA-producing B cells elicited by LPS. However, CD14-independent pathway could be also exist in the LPS-induced activation of B cells that eventually leads to proliferation, IL-6 production and the enhancement of IgM (but not IgA) secretion. It was also indicated that a trigger signal by the LPS from porphyromonas gingivalis as well as other periodontopathic bacteria, prevotella intermedia, Actinobacillus actinomycetemcomitans and Eikenella corrodens, could be transduced through both tyrosine and threonine phosphorylation pathways, and induced the activation of B cells that eventually leads to proliferation. Taken together, the present findings suggest to the LPSs from periodontopathic bacteria have a potent property to induce the stimulate of B cells through the CD14-dependent and independent activation pathways, in which increased tyrosine and threonine phosphorylation could be important signaling events that might lead to cellular responses.