E COLI LT AS A RECTAL AND VAGINAL MUCOSAL ADJUVANT

本项目将检验口服佐剂E.大肠杆菌不耐热毒素（LT）可安全有效地用于增强人体直肠和阴道粘膜对HIV抗原的粘膜和全身免疫应答。在直肠和生殖道分泌物中诱导持久、高滴度HIV特异性抗体的疫苗接种策略可以通过阻断病毒进入这些部位来预防HIV的性传播。 目前的数据表明，局部免疫途径将是产生这些抗体以及粘膜中的抗病毒T辅助（TH）细胞的最佳途径。 然而，增强直肠或阴道接种疫苗应答的粘膜佐剂尚未在人体中发现。具体目的我是确认摄取，并确定最大安全剂量的LT，可以在直肠和阴道的人，并建立一个免疫原性剂量的HIV p55 gag颗粒，可以安全地共同管理LT。妇女组将进行评估后，从1-5 μ g范围内的小剂量的LT在直肠或阴道的副作用。 为了确认LT摄取，将通过ELISA筛选局部分泌物中的抗LT抗体。 然后，将用最大安全LT剂量和250或500 μ g p55对较小的妇女组进行直肠和阴道免疫，以确认组合制剂也是安全的，并确定在局部分泌物中诱导p55特异性抗体所需的p55直肠和阴道剂量。 特异性AIM II是测试LT增强全身和粘膜免疫应答的能力以及通过直肠或阴道途径共同施用的对p55的免疫记忆的发展。 将比较单独用p55或用p55与LT免疫的妇女的血清以及局部和远端分泌物中诱导的抗p55 IgG和伊加抗体的水平。 将通过定量p55刺激的外周血单核细胞体外分泌的特异性IgG亚类抗体和细胞因子来评价TH 1/TH 2型应答的诱导。 通过使用[3 H]胸苷摄取测定测量血液中的淋巴细胞增殖，并通过测量用p55直肠/阴道加强后产生的抗体，评估记忆细胞的建立。这项研究将有助于了解粘膜佐剂对诱导局部和远端免疫反应的影响，设计免疫策略，产生针对性传播疾病的保护性免疫，以及有前途的HIV疫苗亚单位组分的粘膜免疫原性。

This project will test the hypothesis that the oral adjuvant E. coli heat-labile toxin (LT) could be used safely and effectively for enhancing mucosal and systemic immune responses to HIV antigens administered in the rectal and vaginal mucosa of humans. Vaccination strategies that induce durable, high-titered HIV- specific antibodies in rectal and genital tract secretions could prevent sexual transmission of HIV by blocking viral entry at these sites. Current data suggests that local immunization routes would be optimal for generating these antibodies as well as antiviral T helper (TH) cells in the mucosa. However, mucosal adjuvants that augment responses to rectally- or vaginally- administered vaccines have not been identified in humans. Specific AIM I is to confirm uptake and determine the maximal safe dose of LT that can be administered in the rectum and vagina of humans, and to establish an immunogenic dose of HIV p55 gag particles that can be safely co-administered with LT. Groups of women will be evaluated for side effects after small graded doses of LT ranging from 1-5 mug are administered in the rectum or vagina. To confirm LT uptake, local secretions will be screened by ELISA for anti-LT antibodies. Smaller groups of women will then be rectally and vaginally immunized with both maximal safe LT doses and 250 or 500 mug p55 to confirm that the combined preparations are also safe and to establish the rectal and vaginal doses of p55 required for induction of p55-specific antibodies in local secretions. Specific AIM II is to test LT for its ability to enhance systemic and mucosal immune responses and development of immunological memory to p55 co-administered via rectal or vaginal routes. Levels of anti-p55 IgG and IgA antibodies induced in serum and both local and distal secretions of women immunized with p55 alone or p55 with LT will be compared. Induction of TH1/TH2-type responses will be evaluated by quantitating specific IgG subclass antibodies and cytokines secreted in vitro by p55-stimulated peripheral blood mononuclear cells. Memory cell establishment will be assessed by measuring lymphoproliferation in blood using [3H]thymidine uptake assays, and by measuring antibody generated after rectal/vaginal boosting with p55. This study will contribute to knowledge concerning effects of mucosal adjuvants on induction of both local and distal immune responses, design of immunization strategies which produce protective immunity against sexually-transmitted diseases, and mucosal immunogenicity of a promising HIV vaccine subunit component.