REGULATION OF B CELL FUNCTION BY INTERLEUKIN 12

说明(改编自调查人员摘要)：本报告的目的 研究目的是确定体内注射白介素12是否 (IL-12)将改变T非依赖性免疫反应中细胞因子的表达 提高多糖类疫苗接种效果 抗原。IL-12可能特别有益于增强有效性 肺炎球菌和脑膜炎球菌多糖疫苗，因为它 刺激干扰素-γ的产生并增加其分泌 在介导抗细菌免疫方面有效的抗体亚型。 在本研究的实验中，BALB/c和C57BL/6小鼠将 接种IL-12和多糖疫苗，并诱导 此后将在不同的时间监测细胞因子和抗体。这个 IL-12引起细胞因子RNA表达变化的能力将被检测 采用RT-PCR和核糖核酸酶保护试验。级别和具体情况 诱导抗体的数量将使用同型特异性ELISA进行定量。 可能对观察到的影响负责的中间细胞因子将 使用具有细胞因子基因靶向干扰的小鼠和 内源性IL-12在调节反应性中的作用将通过 IL-12基因敲除小鼠。缺乏特异性淋巴样细胞的免疫缺陷小鼠 将利用子集来确定IL-12的影响是否应有 通过结合来激活NK细胞或直接刺激B细胞 新发现的B细胞IL-12受体。细胞的生物学功能 诱导抗体将通过补体结合和 对目标菌株进行调理试验。最后， IL-12增强对致死性肺炎球菌的体内保护作用 脑膜炎双球菌感染将通过直接接种 将毒力强的细菌菌株注入接种的小鼠。由S.S.引起的感染 肺炎和脑膜炎奈瑟氏菌是肺炎的主要原因， 脑膜炎和中耳炎，每年造成约750万例 美国和全球每年超过1亿例。目前的疫苗有 只有有限的效力。因此，使用IL-12作为疫苗佐剂 可能会为预防这些疾病提供一种新的方法，并可能 对人类健康有直接影响。

DESCRIPTION (Adapted from Investigator's abstract): The purpose of this study is to determine whether in vivo administration of interleukin-12 (IL-12) will shift cytokine expression during T-independent immune responses and enhance the effectiveness of vaccination against polysaccharide antigens. IL-12 may be especially beneficial for enhancing the usefulness of pneumococcal and meningococcal polysaccharide vaccines, since it stimulates production of interferon-gamma and increases secretion of antibody isotypes that are efficient in mediating anti-bacterial immunity. For the experiments in this study, BALB/c and C57BL/6 mice will be inoculated with IL-12 and polysaccharide vaccine, and levels of induced cytokines and antibodies will be monitored at various times thereafter. The ability of IL-12 to cause shifts in cytokine RNA expression will be examined by RT-PCR and ribonuclease protection assays. The levels and specificities of induced antibodies will be quantitated using isotype-specific ELISAs. Intermediary cytokines potentially responsible for the observed effects will be identified using mice with targeted disruptions in cytokine genes and the role of endogenous IL-12 in regulating responsiveness will be examined using IL-12 knockout mice. Immunodeficient mice lacking specific lymphoid cell subsets will be exploited to determine whether the effect of IL-12 are due to activated NK cells or to direct stimulation of B-cells through binding to the newly described B-cell IL-12 receptor. The biological functions of the induced antibodies will be determined by complement fixation and opsonization assays against the target bacterial strains. Finally, the ability of IL-12 to enhance in vivo protection against lethal pneumococcal and meningococcal infections will be tested by direct inoculation of virulent bacterial strains into vaccinated mice. Infections due to S. pneumonia and N. meningitidis are the leading causes of pneumonia, meningitis, and otitis media, causing an estimated 7.5 million cases/year in the U.S. and over 100 million cases/year worldwide. Current vaccines are of only limited effectiveness. Thus, the use of IL-12 as a vaccine adjuvant may provide a novel approach for protection against these diseases and could have immediate impact on human health.