B CELL & T CELL RECOGNITION SITES OF P FALCIPARUM GP195

恶性疟原虫的主要裂殖子表面抗原（gp 195）， 它在其他几种疟原虫中的类似物诱导了一种保护性 免疫反应，是一个主要的候选者 血液阶段的疟疾疫苗 酵母重组gp 195 多肽被开发为疫苗抗原。 疗效 这类疫苗的有效性取决于它们诱导 适当的抗原特异性B细胞，并有效地刺激 在抗体中充当辅助/诱导细胞的T细胞 免疫应答或抗体非依赖性免疫应答。 具体 本项目的目的是（1）确定B细胞识别位点 参与对gp 195和gp 195相关的抗体应答 多肽，并确定H-2连接的免疫应答是否 (Ir)基因控制对这些识别位点的反应，（2） 确定T细胞识别位点，研究Ir对T细胞识别位点的调节作用， 基因，并确定T细胞的表面表型诱导 gp 195和重组gp 195相关多肽以及合成的 （3）产生gp 195特异性T细胞系， 表征其精细的特异性和功能（T辅助细胞 活性，γ干扰素的产生），和（4）与相关B细胞 和T细胞识别位点可变的，保守的，或组- GP 195分子的特定区域。 B细胞识别位点将 通过用寄生虫纯化的gp 195免疫小鼠来定义 和gp 195相关多肽以及血清抗体的评价 特异性通过ELISA测定。 T细胞识别位点将被 使用抗原诱导的增殖测定类似地定义，或 抗原特异性T辅助细胞测定。 抗原用于 特异性分析是（1）同源寄生物纯化 gp 195：（2）异源寄生物纯化的gp 195，其不同之处在于 同源蛋白质的组特异性区域;（3）重组 gp 195相关多肽对应于不同的 完整的gp 195蛋白;和（4）合成肽 对应于可变重复区和潜在的免疫- 优势B细胞或T细胞表位通过适当的 计算机算法 Ir基因可能对 对B细胞和T细胞识别位点的反应性将是 通过比较B细胞和T细胞识别位点 利用小鼠不同的只是在H-2连锁的Ir基因。 的 T细胞和B细胞识别位点的表征 可变的、保守的或组特异性的基因尤其与 疫苗设计，并将通过比较抗原 同源与异源gp 195的特异性 蛋白

The major merozoite surface antigen (gp195) of P. falciparum and its analogues in several other Plasmodia induces a protective immune response in simian and murine hosts and is a prime candidate for a blood-stage malaria vaccine. Yeast recombinant gp195-based polypeptides are being developed as vaccine antigens. The efficacy of such vaccines is dependent on their ability to induce the appropriate antigen-specific B cells and to efficiently stimulate T cells which serve as helper/inducer cells in the antibody response or in antibody-independent immune responses. The specific aims of this project are (1) to define B cell recognition sites involved in the antibody responses to gp195 and gp195-related polypeptides and to determine whether H-2-linked immune response (Ir) genes control responsiveness to these recognition sites, (2) to define T cell recognition sites, study their regulation by Ir genes, and determine the surface phenotype of T cells induced by gp195 and recombinant gp195-related polypeptides and synthetic peptides, (3) to generate gp195-specific T cell lines and characterize their fine specificity and function (T helper activity, production of gamma interferon), and (4) to relate B cell and T cell recognition sites to variable, conserved, or group- specific regions of gp195 molecules. B cell recognition sites will be defined by immunization of mice with parasite-purified gp195 and gp195-related polypeptides and evaluation of serum antibody specificity by an ELISA assay. T cell recognition sites will be similarly defined using the antigen-induced proliferation assay or antigen-specific T helper cell assays. Antigens to be used for specificity analyses are (1) the homologous parasite-purified gp195: (2) a heterologous parasite-purified gp195 differing in group specific regions from the homologous protein; (3) recombinant gp195-related polypeptides corresponding to different fragments of the complete gp195 protein; and (4) synthetic peptides corresponding to variable repeat regions and to potential immuno- dominant B cell or T cell epitopes predicted by appropriate computer algorithms. The possible influence of Ir genes on responsiveness to B cell and T cell recognition sites will be studied by comparing the B cell and T cell recognition sites utilized by mice differing only at H-2 linked Ir genes. The characterization of T cell and B cell recognition sites as variable, conserved or group-specific is particularly relevant to vaccine design and will be accomplished by comparing antigen specificity for the homologous versus the heterologous gp195 protein.