ADENOVIRUS FLT3 LIGAND INDUCES NALT DCs FOR SALIVARY GLAND S-lgA Ab RESPONSES

描述(申请人提供)：在过去的五年里，我们研究了诱导和调节唾液分泌型免疫球蛋白抗体(抗体)反应的先天因素和免疫细胞。我们已经证明，编码Flt3配体(FL)、淋巴动蛋白(LTN)、RANTES和MCP-1基因的质粒以及未甲基化的胞嘧啶-鸟嘌呤二核苷酸(CpG ODN)用作鼻佐剂时，既能增强粘膜免疫，又能增强全身免疫反应。给予这些鼻佐剂的小鼠鼻咽相关淋巴网状组织和颌下腺显示树突状细胞(DC)数量增加，是诱导唾液S-IgA抗体应答的关键因素。此外，我们最近的研究使用了表达FL基因的腺病毒(Ad)作为鼻佐剂，显著增强了唾液S-LGA抗体的应答。基于这些发现，我们在这一更新应用中的总体假设是，NALT DC通过处理抗原并随后迁移到SMGs来调节唾液S-LGA抗体的反应。更具体地说，我们假设以FL为基础的佐剂靶向NALT将优先诱导NALT树突状细胞向SMGs迁移，并增强粘膜S-LGA-Ab反应的诱导。我们最近的研究表明，当TLAg和本地霍乱毒素鼻腔免疫小鼠时，T细胞非依赖性唾液S-Ig A抗体反应与SMGs中B-1B细胞数量的增加有关。此外，我们还发现，给予鼻腔TL Ag的小鼠的SMG中，78个T细胞的Toll样受体4(TLR4)表达水平增加。这些结果清楚地表明，先天性和获得性免疫细胞之间的相互作用在诱导抗原特异性唾液S-IgA抗体反应中是重要的，甚至对于TLAgs的免疫反应也是如此。我们推测，以FL佐剂为靶点的NALT诱导NALT DC向SMGs迁移，并与SMGs中的B-1B细胞和y&T细胞相互作用，从而诱导粘膜S-LGA-Ab应答。为了验证我们的假设，我们提出了四个具体目标。我们将：1)通过Ad-FL诱导的CD11b+DC在NALT中表达趋化因子受体，以了解它们的成熟及其在SMGs中的重新定位。2)追踪Ad-FL诱导的NALT DC迁移以诱导唾液S-LGA抗体应答。3)比较Ad-FL诱导的NALT和SMG树突状细胞在诱导CD4‘1’Th1和Th2型细胞因子应答以及长时记忆功能方面的免疫功能。4)确定Ad-FL诱导的唾液树突状细胞、B-1B细胞和YsT细胞之间的串扰对唾液S-IgA抗体应答的确切机制。

DESCRIPTION (provided by applicant): Over the past five years, we have studied the innate factors and immune cells which induce and regulate salivary secretory immunoglobulin (S-lgA) antibody (Ab) responses. We have shown that plasmids encoding the flt3 ligand (FL), lymphotactin (LTN), RANTES and MCP-1 cDNA as well as unmethylated cytosine-guanine dinucleotides oligodeoxynucleotide (CpG ODN), when used as nasal adjuvants, enhance both mucosal and systemic immune responses. Nasopharyngeal-associated lymphoreticular tissues (NALT) and the submandibular glands (SMGs) from mice given these nasal cDNA adjuvants showed increased numbers of dendritic cells (DCs) and were a key factor in the induction of salivary S-lgA Ab responses. Further, our recent study using an adenovirus (Ad) expressing FL cDNA (pFL) when used as nasal adjuvant significantly enhanced salivary S-lgA Ab responses. Based upon these findings, our overall hypothesis in this renewal application is that NALT DCs regulate salivary S-lgA Ab responses by processing Ag followed by their migration into the SMGs. More specifically, we hypothesize that targeting NALT with FL-based adjuvants will preferentially induce migration of NALT DCs into the SMGs and enhance the induction of mucosal S-lgA Ab responses. Our recent study showed that T cell-independent (Tl) Ag-specific salivary S- IgA Ab responses correlated with an increased number of B-1 B cells in the SMGs when mice were immunized nasally with Tl Ag plus native cholera toxin. Further, we found that increased levels of Toll-like receptor four (TLR4) expression by 78 T cells in the SMGs of mice given nasal Tl Ag. These results clearly showed that cross-talk between innate- and acquired-type immune cells was important in the induction of Ag-specific salivary S-lgA Ab responses even for immune responses to Tl Ags. We hypothesize that targeting NALT with FL-based adjuvants induce migration of NALT DCs to the SMGs that interact with B-1 B cells and y& T cells in the SMGs for the induction of mucosal S-lgA Ab responses. In order to test our hypothesis, we propose four Specific Aims. We will: 1) Characterization of chemokine receptor expression by Ad-FL-induced CD11b+ DCs in NALT for their maturation and their relocation into the SMGs. 2) Tracking Ad-FL-induced NALT DC migration for the induction of salivary S-lgA Ab responses. 3) Comparison of Ad- FL-induced NALT and SMG DCs for their immunological function in the induction of CD4'1' Th1- and Th2-type cytokine responses as well as long-lasting memory function. 4) Determination of the precise mechanism for cross-talk between Ad-FL-induced salivary DCs, B-1 B cells and yS T cells for salivary S-lgA Ab responses.