ostertagi, trypsin like domains were up regulated in C. oncophora, and, peptidase S1 S6 was one of the most prevalent domains in female C. oncophora. Given their abundance in the later stages of develop ment, it Inhibitors,Modulators,Libraries is possible that proteins associated with these domains collectively play a role in the feeding process. This is supported in part by the observation that these domains are present in nine secreted peptides in C. oncophora and 75 in O. ostertagi. It is possible that a subset of these is not only secreted from the cell but also from the parasite. Given that the adult diets of these parasites vary based upon either abomasal or intestinal contents, these secreted proteases may also participate either in countering the host immune responses by hydrolyzing antibodies, or in establishment in the host particu larly as it relates to Ostertagia and its need to enter the gastric glands and keep inflammation at bay.
The three Inhibitors,Modulators,Libraries C type lectin domains were GSK-3 the most prevalent domains in male C. oncophora and were up regulated as well in O. ostertagi. As expected, all three of these domains are found in putatively secreted peptides in both species predomin antly because evolutionarily, Inhibitors,Modulators,Libraries the superfamily of proteins containing C type lectin domains is comprised of extracellular metazoan proteins with diverse functions. In general, these domains are involved in calcium dependent carbohydrate binding. However, it should also be noted that not all proteins containing C type lectin domains can actually bind carbohydrates or even Ca2.
Indeed, most of the proteins containing this domain and referred to as C type lectins are not lectins. Nonetheless, those with functionality have been implicated in innate immune responses in invertebrates, and have been linked to proteins involved at the host parasite interface which may assist in evading the host immune response. As such, Inhibitors,Modulators,Libraries differences in the levels of these domains between C. oncophora and O. ostertagi may in part be associated with the observed variation in host immunity as well as distinction in the predilection sites of the re spective L4s and adult worms. A closer investigation of sequence similarity to C type lectins from free living and parasitic nematodes and an analysis of the locus to which these proteins are eventually translocated might shed light on physiological functionalities as they relate either to sustaining life within the organism or control ling the host pathogen interface.
Some nematode C type lectins have been linked to the parasite surface i. e. the epicuticle. Among other things, the nematode cuticle is comprised of collagen proteins and these proteins ex hibit stage specific expression. Examination of KEGG categories demonstrated signifi cant associations between life cycle stages and peptides involved in energy metabolism in O. ostertagi where 24 peptides were found in the free living stages and only four in the parasitic stages.