Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil.
Mycopathologia. 2012 Aug;174(2):93-105. doi: 10.1007/s11046-012-9530-2. Epub 2012 Mar 3.
The conventional treatment for the most prevalent mycosis in Latin America, paracoccidioidomycosis (PCM), involves long periods of therapy that results in side effects and a high frequency of relapses. The search for a new, alternative treatment is necessary. Pb40 is an antigenic protein from P. brasiliensis fraction F0. This fraction has already been shown to have significant protective activity when used as a PCM vaccine in experimental models. The complete cDNA sequence corresponding to Pb40 was cloned into a pET-21a plasmid, expressed in E. coli with a his-tag and purified by affinity chromatography. The predicted protein sequence exhibited nearly 100% homology to a fragment of the hypothetical EF-hand domain containing protein of P. brasiliensis. Immunization with this recombinant protein was used together with chemotherapy in an attempt to improve PCM treatment. The combined drug/rPb40 treatment exhibited long-lasting control of PCM in the liver and spleen and largely preserved the tissue structures of these organs. Despite the lack of a reduction in CFUs in the group that received the combined treatment, there was a significant reduction in the size of the lesions in the lungs after 70 days of infection. At the same time, the IL-10 levels were higher in the treated mice than in the infected-only mice. Moreover, significant levels of rPb40-specific IgG antibodies were detected in the sera of immunized mice. Thus, the treatment protocol consisting of rPb40 immunization in addition to fluconazole chemotherapy showed an additive protective effect after intratracheal challenge, preventing fungal dissemination to other sites of infection and preventing relapses. These results provide new prospects for PCM immunotherapy.
针对在拉丁美洲最为流行的真菌病——副球孢子菌病（PCM），传统的治疗方法需要长期的治疗过程，这会导致副作用和高复发率。因此，有必要寻找新的替代治疗方法。Pb40 是来自巴西副球孢子菌 F0 部分的一种抗原蛋白。该部分已被证明在实验模型中用作 PCM 疫苗时具有显著的保护活性。与 Pb40 相对应的完整 cDNA 序列被克隆到 pET-21a 质粒中，在大肠杆菌中表达并带有 his 标签，然后通过亲和层析进行纯化。预测的蛋白质序列与巴西副球孢子菌的 EF 手结构域蛋白的一个片段具有近 100%的同源性。用该重组蛋白进行免疫接种，并结合化疗，以试图改善 PCM 的治疗效果。联合药物/rPb40 治疗在肝脏和脾脏中对 PCM 具有持久的控制作用，并在很大程度上保留了这些器官的组织结构。尽管联合治疗组的 CFU 数量没有减少，但在感染后 70 天，肺部病变的大小显著减小。同时，治疗组的小鼠中的 IL-10 水平高于仅感染组的小鼠。此外，在免疫接种的小鼠血清中检测到了显著水平的 rPb40 特异性 IgG 抗体。因此，rPb40 免疫接种加氟康唑化疗的治疗方案在经气管内攻击后显示出附加的保护作用，防止真菌传播到其他感染部位，并防止复发。这些结果为 PCM 免疫治疗提供了新的前景。
