RESUMO
Contraceptive vaccines are designed to stimulate autoimmune responses to molecules involved in the reproductive process. A mouse-specific peptide from zona pellucida 3 (mZP3) has been proposed as a target epitope. Here, we employed a plant expression system for the production of glycosylated mZP3 and evaluated the immunogenicity of plant-produced mZP3-based antigens in a female BALB/c mouse model. In the mZP3-1 antigen, mZP3 fused with a T-cell epitope of tetanus toxoid, a histidine tag, and a SEKDEL sequence. A fusion antigen (GFP-mZP3-1) and a polypeptide antigen containing three repeats of mZP3 (mZP3-3) were also examined. Glycosylation of mZP3 should be achieved by targeting proteins to the endoplasmic reticulum. Agrobacterium-mediated transient expression of antigens resulted in successful production of mZP3 in Nicotiana benthamiana. Compared with mZP3-1, GFP-mZP3-1 and mZP3-3 increased the production of the mZP3 peptide by more than 20 and 25 times, respectively. The glycosylation of the proteins was indicated by their size and their binding to a carbohydrate-binding protein. Both plant-produced GFP-mZP3-1 and mZP3-3 antigens were immunogenic in mice; however, mZP3-3 generated significantly higher levels of serum antibodies against mZP3. Induced antibodies recognized native zona pellucida of wild mouse, and specific binding of antibodies to the oocytes was observed in immunohistochemical studies. Therefore, these preliminary results indicated that the plants can be an efficient system for the production of immunogenic mZP3 peptide, which may affect the fertility of wild mice.
RESUMO
Human-wildlife conflicts, a growing and sad reality worldwide, makes population control of wildlife and feral animals one of the biggest challenges in wildlife management, especially due to the rapidly expanding human population, and consequently the ever-diminishing natural habitats of animals. Human activities and the destruction of nature forcing wildlife to move inevitably into urban and agricultural areas, causing "conflicts", such as the risk of zoonosis and traffic accidents, as well as damage to crops in the search for food, whose losses reach millions of dollars. For decades, science has been engaged in extensive efforts to develop methods of "humane" population control methods, and many techniques are being employed in order to control wildlife population. In this article, we present an overview of applied contraceptive methods with simplified graphic demonstrations of their interactions with reproductive physiology, furthermore relating pro and contra of utilized antifertility agents. These are being compared to a set of desired characteristics for free-ranging wildlife for in-field applications, with emphasis on reversible immunocontraception concluding, therefore, the reasons why this concept is becoming the most appropriate and promising for free-ranging wildlife.(AU)
Os conflitos Humanos-Animais Selvagens são uma realidade crescente e triste no mundo inteiro, tornando o controle populacional da fauna silvestre e animais ferais o maior desafio, principalmente diante do crescimento da população humana e, consequentemente, da diminuição dos habitats naturais dos animais. As atividades humanas e a destruição da natureza, forçam os animais de vida livre a se dirigirem para áreas urbanas e agrícolas, inevitavelmente, causando conflitos, como o risco de zoonoses, acidentes de trânsito, bem como danos às plantações, quando em busca de alimentos, cujo prejuízo chega a milhões de dólares. Durante décadas, a ciência esteve empenhada em esforços extensivos para desenvolver métodos de controle populacional "humano"; e muitas técnicas foram utilizadas, a fim de se realizar um controle populacional destes animais silvestres. Neste artigo será apresentada uma visão geral dos métodos anticoncepcionais aplicados, com demonstrações gráficas simplificadas de suas interações com a fisiologia reprodutiva, bem como relacionando os prós e os contras dos agentes antifertilidade empregados; também serão comparados com um conjunto de características desejadas para as aplicações em fauna a campo, com ênfase em imunocontracepção reversível, concluindo assim, com as razões do porque este conceito torna-se o mais apropriado e promissor para animais silvestres de vida livre.(AU)
