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

描述（由申请人提供）：在过去的五年中，我们研究了诱导和调节唾液分泌型免疫球蛋白（S-IgA）抗体（Ab）应答的先天因子和免疫细胞。我们已经证明，编码flt 3配体（FL）、趋化因子（LTN）、RANTES和MCP-1 cDNA以及未甲基化胞嘧啶-鸟嘌呤二核苷酸寡脱氧核苷酸（CpG ODN）的质粒，当用作鼻佐剂时，增强粘膜和全身免疫应答。给予这些鼻cDNA佐剂的小鼠的鼻咽相关淋巴网状组织（NALT）和下颌下腺（SMG）显示树突状细胞（DC）数量增加，并且是诱导唾液S-IgA Ab应答的关键因素。此外，我们最近的研究使用表达FL cDNA的腺病毒（Ad）（pFL）作为鼻佐剂时显著增强唾液S-IgA Ab应答。基于这些发现，我们在该更新申请中的总体假设是NALT DC通过加工Ag随后其迁移到SMG中来调节唾液S-IgA Ab应答。更具体地，我们假设用基于FL的佐剂靶向NALT将优先诱导NALT DC迁移到SMG中并增强粘膜S-IgA Ab应答的诱导。我们最近的研究表明，当用TlAg加天然霍乱毒素经鼻免疫小鼠时，T细胞非依赖性（TlAg）特异性唾液伊加Ab应答与SMG中B-1 B细胞数量的增加相关。此外，我们发现在给予鼻TlAg的小鼠的SMG中的78个T细胞的Toll样受体4（TLR 4）表达水平增加。这些结果清楚地表明，先天型和获得型免疫细胞之间的串扰在诱导Ag特异性唾液S-IgA Ab应答中是重要的，甚至对于针对TlAg的免疫应答也是如此。我们假设用基于FL的佐剂靶向NALT诱导NALT DC向SMG的迁移，所述SMG与SMG中的B-1 B细胞和γ & T细胞相互作用以诱导粘膜S-IgA 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）在NALT中Ad-FL诱导的CD 11b + DC的趋化因子受体表达的表征，用于它们的成熟和它们重新定位到SMG中。2)追踪Ad-FL诱导的NALT DC迁移以诱导唾液S-IgA Ab应答。3)比较Ad-FL诱导的NALT和SMG DC在诱导CD 4 +/-Th 1和Th 2型细胞因子应答以及持久记忆功能方面的免疫功能。4)确定Ad-FL诱导的唾液DC、B-1 B细胞和γ S T细胞之间对于唾液S-IgA Ab应答的串扰的精确机制。

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.