Induction of Immunity in Human Genital Tract: Effect of Intranasal Immunization

描述(由申请人提供)：通过获得强大的局部免疫力，可以防止通过生殖道粘膜表面获得的感染。在人类女性和男性生殖道中，抗体(Abs)是局部产生的，也是由血浆产生的。基于这种双重来源，人们可以假设，特异性抗体可以通过全身免疫或粘膜免疫来诱导。然而，我们以前的免疫研究结果表明，只有通过全身、口腔或直肠途径在人类生殖道中才能获得低水平的抗体。相反，实验动物的鼻内(IN)免疫导致弥漫性粘膜(尤其是生殖道中强烈的)，以及循环反应。我们的目标是确定在实验动物中产生的结果是否可以在人类身上得到验证。我们假设：1.在人类生殖道中产生强烈的免疫反应可以通过IN免疫来完成；2.由于抗原激活的细胞优先向生殖器组织“归巢”，该途径将比肠外或其他粘膜接种途径更有效。为了解决这一问题，我们建议用一种模型抗原-流感病毒对女性和男性志愿者进行免疫，这种病毒虽然与生殖道感染无关，但是唯一可用于鼻腔应用的商业疫苗，也可以通过注射的形式获得。为了评价IN免疫对生殖道免疫的有效性，我们建议：1.测定和表征IN与非肠道免疫在人女性和男性生殖道诱导的免疫反应。局部和循环对诱导反应的贡献将通过对生殖道分泌物与血清和其他外部分泌物(唾液、鼻腔和直肠冲洗液)中的抗体进行定量和定性分析来确定。我们将测定：抗体亚型(特别是Ig A和Ig G亚类)的水平和相对比例，Ig A的分子形式(S-Ig A、MIGA和PIGA)，以及Abs对流感病毒的中和能力。2.确定与肌肉免疫相比，IN是否有利于疫苗致敏细胞迁移到生殖道以产生局部反应。具体地说，我们将比较外周血细胞在分泌流感病毒特异性抗体和产生干扰素方面的功能，这些外周血细胞表达的归巢受体优先归巢到生殖道(整合素)或次级淋巴组织(L-选择素)。这些研究结果将有助于了解人类生殖道免疫反应的起源和诱导。这些信息将有助于设计有效的防止性传播疾病，包括艾滋病毒的疫苗接种战略。我们的目标是证明是否可以通过鼻内免疫(与肌肉内免疫相比)在人类男性和女性生殖道实现高效的疫苗特异性反应，以及这与疫苗致敏细胞的归巢模式有何关系。所获得的结果将对制定免疫战略以防止性传播疾病病原体感染具有重要意义。

DESCRIPTION (provided by applicant): Protection against infections acquired through the mucosal surfaces of the genital tract can be achieved by the acquisition of strong local immunity. In human female and male genital tracts, antibodies (Abs) are locally produced, as well as plasma-derived. Based on this dual origin, one can assume that specific Abs can be induced either by systemic or mucosal immunizations. However, results of our previous immunization studies indicate that only low levels of Abs can be achieved in the human genital tract by systemic, oral, or rectal routes. In contrast, intranasal (IN) immunization of experimental animals resulted in disseminated mucosal (particularly strong in the genital tract), as well as circulatory responses. Our goal is to determine whether the results generated in the experimental animals can be validated in humans. We hypothesize that: 1. Generation of strong immune responses in the human genital tract can be accomplished by IN immunization; and 2. This route will be more efficient than the parenteral or other mucosal routes of vaccination, due to the preferential "homing" migration of antigen-activated cells to the genital tissues. To address this, we propose to immunize female and male human volunteers with a model antigen, influenza virus that, although not relevant for the genital tract infections, is the only commercially available vaccine for nasal application and is also obtainable in an injectable form. To evaluate the effectiveness of IN immunization for genital tract immunity, we propose to: 1. Determine and characterize the immune responses induced in human female and male genital tracts by the IN vs. the parenteral vaccination. The local and circulatory contribution to the induced responses will be determined by quantitative and qualitative analysis of Abs in the genital tract secretions, compared to sera and other external secretions (saliva; nasal and rectal lavages). We will determine: levels and relative proportion of Ab isotypes (particularly of IgA and IgG subclasses), the molecular forms of IgA (S-IgA, mIgA and pIgA), and the capacity of Abs to neutralize influenza virus. 2. Determine whether IN, compared to intramuscular immunization, will favor the migration of vaccine-sensitized cells to the genital tract to generate local responses. Specifically, we will compare the function of peripheral blood cells, expressing homing receptors for preferential homing to the genital tract (¿4¿1 integrin) or to secondary lymphoid tissues (L-selectin), with respect to the secretion of influenza virus-specific Abs and production of IFN-¿. The results of these studies will contribute to the understanding of the origin and the induction of immune responses in the human genital tract. This information will be useful for the design of effective vaccination strategies against sexually transmitted diseases, including HIV. Our goal is to demonstrate whether efficient, vaccine-specific responses in the human male and female genital tract can be achieved by intranasal immunization (compared to intramuscular), and how this relates to the homing pattern of vaccine-sensitized cells. The results obtained will be important for the design of immunization strategies to prevent infections with agents of sexually transmitted diseases.