SALIVARY IGA RESPONSE--REGULATION BY TH1 AND TH2 CELLS

口腔中的分泌型伊加（S-IgA）反应由抗原引起， 在伊加诱导位点如派伊尔集合淋巴结（PP）中的刺激。 口服 免疫诱导两种T辅助（Th）细胞，其优先支持 PP中伊加反应和伊加定型（表面伊加+; sIgA+）B细胞; 然而，伊加应答的最后阶段并不发生在该组织中。 相反，sIgA+ B细胞在抗原刺激后离开PP并迁移 到远处的伊加效应位点，包括唾液腺（SG）以及 肠、支气管和肺的固有层（LP）区域 泌尿生殖道，S-IgA抗体反应发生的地方。 我们的研究 已经表明，优先支持伊加的鼠PP Th细胞， 反应，产生IL-5和IL-6，这表明它们被分类为Th 2 类型. PP还含有Th 1细胞（产生IFN γ和IL-2）; 与脾脏Th细胞类型相似。 Th 2型细胞在 脾支持IgM和IgG应答，但不支持伊加应答。 另一方面，伊加 效应位点，例如，小肠的LP，含有较高的 产生IL-5和IL-6的Th 2细胞的频率。 通过这些研究，我们 假设伊加诱导和效应位点的Th 2细胞不同于 从全身组织获得的那些，尽管两种类型都产生IL-4、IL-5 和IL-6 在这项研究中，我们将确定是否Th 2细胞的伊加反应， 发生在SG中，并且如果它们起源于PP中的Th 2细胞前体。 这些 研究还将包括T细胞受体的表征， 例如，在一个实施例中，SG T细胞使用的γ δ与α。 因此，频率 将检查携带TCR 1（γ δ）和TCR 2（α）的T细胞的数量 分别用单抗UC 7 - 13 D5和H57.597在不同的SG T亚群中， 细胞，包括CD 4+或CD 8+或CD 4-、CD 8-部分。 由于TCR 1 + T细胞 来自不同组织的使用不同的V γ基因片段（例如，Vgamma6 舌和Vgamma 7上皮内淋巴细胞），主要的家庭 将阐明SG TCR 1 + T细胞的V γ基因区段的特性。 这 提案还将解决是否存在于SG中的Th 1和Th 2细胞 通过丝氨酸特异性ELISPOT产生不同的细胞因子模式， 使用新鲜分离的T细胞的mRNA-cDNA杂交和抗原特异性免疫印迹。 来自SG的T细胞克隆。 为了鉴定Th 1或Th 2型细胞因子的产生， 单细胞水平的SG中的细胞，在原位的精氨酸特异性 将采用杂交。 我们将直接讨论为什么Th 2细胞 伊加反应在PP和SG中发展，以及负责的机制 他们的归纳。 为此目的，将通过以下方法重建SCID小鼠： PP CD 4 + T细胞或抗原特异性T细胞克隆。 此外，可能 参与PP和SG中的抗原呈递细胞，以及神经肽和 用于诱导SG中独特的Th 2细胞亚群的激素将是 研究了 最后，我们将确定Th 2-B细胞相互作用， B细胞终末分化为血浆所需的细胞因子 SG中的细胞。 这些研究将建立在细胞和 分子水平，T细胞如何调节唾液S-IgA反应。

Secretory IgA (S-IgA) responses in the oral cavity result from antigen stimulation in IgA inductive sites such as the Peyer's patches (PP). Oral immunization induces both T helper (Th) cells which preferentially support IgA responses and IgA committed (surface IgA+; sIgA+) B cells in PP; however, the final stages of IgA responses do not occur in this tissue. Instead, sIgA+ B cells leave PP following antigen stimulation and migrate to distant IgA effector sites including the salivary glands (SG) as well as the lamina propria (LP) regions of the intestinal, bronchus and genitourinary tracts, where S-IgA antibody responses occur. Our studies have shown that murine PP Th cells, which preferentially support IgA responses, produce IL-5 and IL-6 which suggest their classification as Th2 type. The PP also contain Th1 cells (producing IFNgamma and IL-2); which is similar to those Th cell types from spleen. However, Th2-type cells in spleen support IgM and IgG, but not IgA responses. On the other hand, IgA effector sites, e.g., the LP of the small intestine, contained a higher frequency of IL-5 and IL-6 producing Th2 cells. From these studies, we postulate that Th2 cells in IgA inductive and effector sites differ from those obtained from systemic tissue, although both types produce IL-4, IL-5 and IL-6. In this grant, we will determine if Th2 cells for IgA responses occur in SG and if they originate from Th2 cell precursors in PP. These studies will also include the characterization of the T cell receptor, e.g., gammadelta versus alphabeta used by SG T cells. Thus, the frequency of TCR1 (gammadelta) and TCR2 (alphabeta) bearing T cells will be examined by mAb UC7-13D5 and H57.597, respectively, in different subsets of SG T cells including CD4+ or CD8+ or CD4-, CD8-fractions. Since TCR1+ T cells from different tissues use different Vgamma gene segments (e.g., Vgamma6 for tongue and Vgamma7 for intraepithelial lymphocytes), the major family of Vgamma gene segments for SG TCR1+ T cells will be elucidated. This proposal will also address whether Th1 and Th2 cells which reside in SG produce a distinct pattern of cytokines by cytokine-specific ELISPOT and mRNA-cDNA hybridization using freshly isolated T cells and antigen-specific T cell clones from SG. To identify Th1- or Th2-type cytokine producing cells in SG at the single cell level, cytokine-specific in situ hybridization will be employed. We will directly address why Th2 cells for IgA responses develop in the PP and SG, and the mechanism(s) responsible for their induction. For this purpose, SCID mice will be reconstituted by PP CD4+ T cells or antigen-specific T cell clones. Further, possible involvement of antigen-presenting cells in PP and SG, and neuropeptides and hormones for the induction of unique subsets of Th2 cells in SG will be studied. Finally, we will determine the Th2-B cell interactions and cytokine requirements for terminal differentiation of B cells into plasma cells in the SG. These studies will establish at the cellular and molecular levels, how T cells regulate salivary S-IgA response.