Bromuro C, La Valle R, Sandini S, Urbani F, Ausiello C M, Morelli L, Fé d'Ostiani C, Romani L, Cassone A
Department of Bacteriology, Istituto Superiore di Sanità, Rome, Italy.
Infect Immun. 1998 May;66(5):2154-62. doi: 10.1128/IAI.66.5.2154-2162.1998.
The 70-kDa recombinant Candida albicans heat shock protein (CaHsp70) and its 21-kDa C-terminal and 28-kDa N-terminal fragments (CaHsp70-Cter and CaHsp70-Nter, respectively) were studied for their immunogenicity, including proinflammatory cytokine induction in vitro and in vivo, and protection in a murine model of hematogenous candidiasis. The whole protein and its two fragments were strong inducers of both antibody (Ab; immunoglobulin G1 [IgG1] and IgG2b were the prevalent isotypes) and cell-mediated immunity (CMI) responses in mice. CaHsp70 preparations were also recognized as CMI targets by peripheral blood mononuclear cells of healthy human subjects. Inoculation of CaHsp70 preparations into immunized mice induced rapid production of interleukin-6 (IL-6) and tumor necrosis factor alpha, peaking at 2 to 5 h and declining within 24 h. CaHsp70 and CaHsp70-Cter also induced gamma interferon (IFN-gamma), IL-12, and IL-10 but not IL-4 production by CD4+ lymphocytes cocultured with splenic accessory cells from nonimmunized mice. In particular, the production of IFN-gamma was equal if not superior to that induced in the same cells by whole, heat-inactivated fungal cells or the mitogenic lectin concanavalin A. In immunized mice, however, IL-4 but not IL-12 was produced in addition to IFN-gamma upon in vitro stimulation of CD4+ cells with CaHsp70 and CaHsp70-Cter. These animals showed a decreased median survival time compared to nonimmunized mice, and their mortality was strictly associated with organ invasion by fungal hyphae. Their enhanced susceptibility was attributable to the immunization state, as it did not occur in congenitally athymic nude mice, which were unable to raise either Ab or CMI responses to CaHsp70 preparations. Together, our data demonstrate the elevated immunogenicity of CaHsp70, with which, however, no protection against but rather some enhancement of Candida infection seemed to occur in the mouse model used.
对70 kDa重组白色念珠菌热休克蛋白（CaHsp70）及其21 kDa C端和28 kDa N端片段（分别为CaHsp70-Cter和CaHsp70-Nter）的免疫原性进行了研究，包括体外和体内促炎细胞因子的诱导，以及在血源性念珠菌病小鼠模型中的保护作用。完整蛋白及其两个片段都是小鼠抗体（Ab；免疫球蛋白G1 [IgG1]和IgG2b是主要亚型）和细胞介导免疫（CMI）反应的强诱导剂。CaHsp70制剂也被健康人类受试者的外周血单核细胞识别为CMI靶点。将CaHsp70制剂接种到免疫小鼠中可诱导白细胞介素-6（IL-6）和肿瘤坏死因子α迅速产生，在2至5小时达到峰值，并在24小时内下降。CaHsp70和CaHsp70-Cter还可诱导γ干扰素（IFN-γ）、IL-12和IL-10产生，但与来自未免疫小鼠的脾辅助细胞共培养的CD4+淋巴细胞不产生IL-4。特别是，IFN-γ的产生即使不优于也等同于由完整的、热灭活的真菌细胞或促有丝分裂凝集素伴刀豆球蛋白A在相同细胞中诱导产生的IFN-γ。然而，在免疫小鼠中，用CaHsp70和CaHsp70-Cter体外刺激CD4+细胞后，除了IFN-γ外还产生了IL-4，但未产生IL-12。与未免疫小鼠相比，这些动物的中位生存时间缩短，其死亡率与真菌菌丝的器官侵袭密切相关。它们易感性增强归因于免疫状态，因为在先天性无胸腺裸鼠中未出现这种情况，裸鼠无法对CaHsp70制剂产生Ab或CMI反应。总之，我们的数据证明了CaHsp70具有较高的免疫原性，然而，在所使用的小鼠模型中，它似乎没有提供对念珠菌感染的保护作用，反而在一定程度上增强了感染。
