Biological Sciences Institute, Universidade de Brasília, Brasília.
Br J Pharmacol. 2010 Mar;159(5):1126-32. doi: 10.1111/j.1476-5381.2009.00617.x. Epub 2010 Feb 5.
The present study reports on the preparation and testing of a sustained delivery system for the immunomodulatory peptide P10 aimed at reducing the in vivo degradation of the peptide and the amount required to elicit a protective immune response against paracoccidioidomycosis.
BALB/c mice were infected with the yeast Paracoccidioides brasiliensis to mimic the chronic form of paracoccidioidomycosis. The animals were treated daily with sulfamethoxazole/trimethoprim alone or combined with peptide P10, either emulsified in Freund's adjuvant or entrapped in poly(lactic acid-glycolic acid) (PLGA) nanoparticles at different concentrations (1 microg, 5 microg, 10 microg, 20 microg or 40 microg.50 microL(-1)). Therapeutic efficacy was assessed as fungal burden in tissues and the immune response by quantitative determination of cytokines.
Animals given combined chemotherapy and P10 nanotherapy presented a marked reduction of fungal load in the lungs, compared with the non-treated animals. After 30 days of treatment, P10 entrapped within PLGA (1 microg.50 microL(-1)) was more effective than 'free' P10 emulsified in Freund's adjuvant (20 microg.50 microL(-1)), as an adjuvant to chemotherapy. After treatment for 90 days, the higher doses of P10 entrapped within PLGA (5 or 10 microg.50 microL(-1)) were most effective. Treatment with P10 emulsified in Freund's adjuvant (20 microg.50 microL(-1)) or P10 entrapped within PLGA (1 microg.50 microL(-1)) were accompanied by high levels of interferon-gamma in lung.
Combination of sulfamethoxazole/trimethoprim with the P10 peptide entrapped within PLGA demonstrated increased therapeutic efficacy against paracoccidioidomycosis. P10 incorporation into PLGA nanoparticles dramatically reduced the peptide amount necessary to elicit a protective effect.
本研究报告了一种免疫调节肽 P10 的缓释系统的制备和测试，旨在减少肽的体内降解和产生针对副球孢子菌病的保护性免疫反应所需的量。
用酵母巴西副球孢子菌感染 BALB/c 小鼠，模拟副球孢子菌病的慢性形式。动物每天用磺胺甲恶唑/甲氧苄啶单独或与肽 P10 联合治疗，P10 分别用弗氏佐剂乳化或包封在聚乳酸-羟基乙酸（PLGA）纳米粒子中，浓度分别为 1μg、5μg、10μg、20μg 或 40μg（50μL（-1））。通过定量测定细胞因子评估治疗效果，即组织中的真菌负荷和免疫反应。
与未治疗的动物相比，联合化疗和 P10 纳米治疗的动物肺部真菌负荷明显降低。治疗 30 天后，包封在 PLGA 中的 P10（1μg.50μL（-1））比乳化在弗氏佐剂中的“游离”P10（20μg.50μL（-1））更有效，作为化疗的佐剂。治疗 90 天后，包封在 PLGA 中的较高剂量的 P10（5 或 10μg.50μL（-1））最有效。用弗氏佐剂乳化的 P10（20μg.50μL（-1））或包封在 PLGA 中的 P10（1μg.50μL（-1））治疗后，肺中的干扰素-γ水平较高。
磺胺甲恶唑/甲氧苄啶与包封在 PLGA 中的 P10 肽联合使用，对副球孢子菌病的治疗效果增加。将 P10 掺入 PLGA 纳米粒子中，大大减少了产生保护作用所需的肽量。
