RESUMEN
Trypanosoma cruzi is a flagellate protozoan pathogen that causes Chagas disease. Currently there is no preventive treatment and the efficiency of the two drugs available is limited to the acute phase. Therefore, there is an unmet need for innovative tools to block transmission in endemic areas. In this study, we engineered a novel recombinant molecule able to adhere to the T. cruzi surface, termed scFv-10D8, that consists of a single-chain variable fragment (scFv) derived from mAb-10D8 that targets gp35/50. The synthetic gene encoding scFv-10D8 was cloned and fused to a 6×His tag and expressed in a prokaryotic expression system. Total periplasmic or 6xHis tag affinity-purified fractions of scFv-10D8 retained the capacity to bind to gp35/50, as shown by Western blot analyses. Pre-incubation of metacyclic trypomastigotes with scFv-10D8 showed a remarkable reduction in cell invasion capacity. Our results suggest that scFv-10D8 can be used in a paratransgenic approach to target parasites in insect vectors, avoiding dissemination of infective forms. Such advances in the development of this functional molecule will surely prompt the improvement of alternative strategies to control Chagas disease by targeting mammalian host stages.
Asunto(s)
Antígenos de Protozoos/inmunología , Ingeniería de Proteínas/métodos , Anticuerpos de Cadena Única/genética , Trypanosoma cruzi/inmunología , Anticuerpos Antiprotozoarios/genética , Anticuerpos Antiprotozoarios/farmacología , Línea Celular , Enfermedad de Chagas/tratamiento farmacológico , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/prevención & control , Células HeLa , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Anticuerpos de Cadena Única/farmacología , Trypanosoma cruzi/efectos de los fármacosRESUMEN
Background: Some studies indicated that body mass index (BMI) is inversely proportional to serum testosterone concentrations in men. Purposes: This study aimed to analyze the effects of aging and obesity on total testosterone (TT), free testosterone (FT), bioavailable testosterone (BT), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) levels. Methods: A cross-sectional study was performed to assess the clinical and laboratory profiles of 701 patients treated at a private urology clinic in Ponta Grossa, Brazil, from January 2016 to December 2018. Results: Patients' age ranged from 16 to 88 years (mean, 56.9 ± 13.62 years). Age did not significantly influence serum TT concentrations, except compared to patients aged >70 years. However, changes were observed in FT and BT (p < 0.05). The mean SHBG increased with age (p < 0.05). A tendency toward LH elevation was observed in older patients, but it was not statistically significant. An inverse proportional relationship between TT, FT, and BT and the testosterone deficiency rate (TT < 300 ng/dL) was observed within BMI groups (p < 0.05). The testosterone deficiency rate was 21.5% in individuals with normal BMI, 29% in overweight individuals, and 37% in obese individuals. Conclusions: Aging affected the testosterone concentrations in men and became increasingly evident using FT and BT instead of TT. SHBG increased with age. Obesity was associated with a decrease in TT, FT, and BT but also increased the rate of hypogonadism. (AU)
Fundamentos: Alguns estudos indicam que o índice de massa corporal (IMC) é inversamente proporcional à con-centração de testosterona sérica em homens. Objetivos: O objetivo deste estudo é analisar o efeito do envelhe-cimento e da obesidade na testosterona biodisponível total e livre, bem como nos níveis de hormônio luteinizante e globulina ligadora de hormônio sexual. Métodos: Foi realizado um estudo transversal abordando o perfil clínico e laboratorial de 701 pacientes atendidos em uma clínica privada de urologia em Ponta Grossa, Brasil, de janei-ro de 2016 a dezembro de 2018. Resultados: A idade dos pacientes variou de 16 a 88 anos (média de 56,9 ± 13,62 anos). A idade não influenciou significativamente as concentrações séricas de testosterona total, exceto quando comparada a pacientes com mais de 70 anos. No entanto, foi observada diferença na testosterona livre e biodisponível (p <0,05). A média de globulina de ligação aos hormônios sexuais aumentou com a idade (p <0,05). Embora uma tendência à elevação da luteinização tenha sido observada em pacientes mais idosos, ela não foi significativa. Relação inversa entre testosterona total, livre e biodisponível e taxa de deficiência de testosterona (testosterona total <300 ng / dL) foi observada dentro dos grupos de índice de massa corporal (p <0,05). A taxa de deficiência de testosterona em indivíduos com índice de massa corporal normal foi de 21,5%, indivíduos com sobre-peso foi de 29% e em indivíduos com obesidade foi de 37%. Conclusões: O envelhecimento afetou a concentração de testosterona em homens, mais evidente ao avaliar testosterona livre e biodisponível em vez de testosterona total. A globulina de ligação aos hormônios sexuais aumentou com a idade. A obesidade foi associada à redução da testosterona total, livre e biodisponível e ao aumento da taxa de hipogonadismo. (AU)