Bovine (Bos taurus) humoral immune response against Echinococcus granulosus and hydatid cyst infertility

Abstract

Echinococcus granulosus, the agent of hydatid disease, presents an indirect life cycle, with canines (mainly dogs) as definitive hosts, and herbivores and human as intermediary ones. In intermediary hosts fertile and infertile cysts develop, but only the first ones develop protoscoleces, the parasite form infective to definitive hosts. We report the presence of bovine IgGs in the germinal layer from infertile cysts (GLIC), in an order of magnitude greater than in the germinal layer from fertile cysts (GLFC). When extracted with salt solutions, bovine IgGs from GLIC are associated with low or with high affinity (most likely corresponding to non specific and antigen specific antibodies, respectively). Specific IgGs penetrate both the cells of the germinal layer and HeLa cultured cells and recognize parasitic proteins. These results, taken together with previous ones from our laboratory, showing induction of apoptosis in the germinal layer of infertile hydatid cysts, provide the first coherent explanation of the infertility process. They also offer the possibility of identifying the parasite antigens recognized, as possible targets for immune modulation.

Acute-phase responses in cattle infected with hydatid cysts and microbial agents

“…Cysts that contained no protoscolex, as well as being heavily supurative or calcified, were considered infertile (Paredes et al, 2011). The number of cysts was recorded according to organ distribution.…”

Cystic Echinococcosis: Aspects of Immune Response, Immunopathogenesis and Immune Evasion from the Human Host

“…In this last structure, IgGs recognize specific antigens involved in the cell proliferation process and/or in the differentiation mechanisms leading to protoscolex formation. This antigen-antibody interaction may inhibit cell proliferation and/or cell differentiation involved in the formation of buds and protoscoleces and may induce apoptosis leading to cyst infertility [7]. The hydatid liquid is clean and clear, "as well as the clean water from its natural source", containing secretions from both the parasite and host and all the elements from the "inner wall" of the cyst, named hydatid sand [1].…”

Hiperendemia de equinococosis y fertilidad quística en porcinos del valle interandino de Huancarama, Perú

“…Las inmunoglobulinas producidas por el hospedero penetran las células de la capa germinal, se ubican mayoritariamente en el núcleo, impiden la formación de yemas y protoescólices e inhiben la proliferación celular o induce apoptosis. Así mismo, la inmunidad natural podría impedir el desarrollo y crecimiento de protoescólices y mantener el quiste en un estado infértil, lo que en las hembras podría verse mermado, debido a mecanismos inmunodepresores durante la parición (20) . El porcentaje de fertilidad de quistes en ˂2 años y ≥2 años no estuvo asociado al sexo.…”