Parasitic Nematode Interactions with Mammals and Plants

Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent reinfection of host species. In addition, development of resistance to nematicides and anthelmintics by these parasites and reduced availability of some nematicides, for environmental protection, pose significant obstacles for current and future prospects of effective parasite control. Due to marked differences in host species, research on animal and plant parasitic nematodes often proceeds independently. Despite the differences between animals and plants, basic cellular properties are shared among these host organisms. Some common properties may be important for mechanisms [homologous or convergent (homoplastic)] by which nematodes successfully infect these diverse hosts or by which animal and plant hosts resist infections by these pathogens. Here we compare host/parasite interactions between plant parasitic nematodes (PPN) and animal parasitic nematodes, with an emphasis on mammalian hosts (MPN). Similarities and differences are considered in the context of progress on molecular dissection of these interactions. A comprehensive coverage is not possible in the space allotted. Instead, an illustrative approach is used to establish examples that, it is hoped, exemplify the value of the comparative approach

Monoclonal antibody to a conserved epitope on proteins encoded by Babesia bigemina and present on the surface of intact infected erythrocytes

To define Babesia bigemina-specific antigens on the surface of infected erythrocytes, monoclonal antibodies (MAbs) were identified by live-cell immunofluorescence. As determined by live-cell immunofluorescence, two MAbs made to the Mexico strain reacted with the Mexico strain and three Kenya strains, while three MAbs made to the Kenya-Ngong strain reacted with the Kenya strains but not the Mexico strain. Binding of MAb 44.18 (made to the Mexico strain) to a strain-common epitope was confirmed by immunoelectron microscopy and by surface-specific immunoprecipitation of (35S) methionine-labeled proteins (200, 28 and 16 kDa in size), which also demonstrated that the MAb recognized an epitope on proteins encoded by B. bigemina. In immunoblots, the MAb bound to predominant antigens with sizes of 200 and 220 kDa in erythrocyte lysates infected with strains from Puerto Rico, St. Croix, Texcoco (Mexico), Kenya, and Mexico. Major antigens with sizes of antigens bound to erythrocytes infected with either the Mexico or Kenya strains as determined by live-cell immunofluorescence, allowing the conclusion that at least one conserved surface epitope was recognized. Calf precipitation, and infected erythrocytes sensitized with these antibodies were phagocytized by cultured bovine peripheral blood monocytes. These results provide a rationable for evaluating antigens identified by MAb 44.18 individually and as components of subunit vaccines