Cantly higher than when compared against all genes with specific transcription in parasitic and free-living stages, respectively. These findings suggest that, while most ES proteins are deployed during the lifecycle, a considerable number are specifically associated with particular functions in either the parasitic- or free-living stages of the worm. A total of 162 genes were predicted to encode ES proteins likely to have immunomodulatory or immunogenic functions, many of which were transcribed at high levels in both parasitic stages; 27% of them are `over-transcribed’ in parasitic stages. Conspicuous were transcripts encoding numerous peptidases, SCP/Tpx-1/Ag5/PR-1/Sc7, transthyretin-like and FAR binding proteins as well as eicosanoids. A set of 160 genes was inferred to encode ES peptidases in the L4 and adult stages with abundant transcription. These genes encoded mainly cysteine-type, serine-type and metallopeptidases as well as some aspartate- and threoninetype peptidases. In addition, transcription of genes encoding 75 peptidase inhibitors was assessed. Many secreted peptidases likely to represent the `degradome’ and respective inhibitors are known to enable parasitic worms to invade, penetrate tissue HC-030031 biological activity barriers and feed; some of them have been reported to induce or modulate the host’s immune response against the parasite. A large repertoire of genes encoding SCP/TAPS proteins was predicted; these molecules are characterized by the Aphrodine web presence of SCP-like domains. Of the 284 predicted SCP/TAPS proteins, 167 were inferred to be ES molecules and 119 were transcribed exclusively in the parasitic stages as compared with only 19 transcribed exclusively Biotechnol Adv. Author manuscript; available in PMC 2016 November 01. Tyagi et al. Page 9 in free-living stages. In total, 179 of the predicted SCP/TAPS proteins did not have orthologs in H. contortus, N. americanus or C. elegans, and only 16 had C. elegans orthologs, similar to recent observations in Necator. The large number of genes encoding SCP/TAPS proteins in O. dentatum compared with only 34 such genes in C. elegans suggests that many of these proteins are involved in functions specific to O. dentatum, with potential relevance to parasitism and/or disease. Some of the SCP/ TAPS proteins predicted were classified as NIFs, 30 of which were predicted to be ES proteins with immunobiological roles. Although NIFs had not been reported previously for O. dentatum, the SCP-1 homolog in Ancylostoma caninum binds the canine integrin CR3 and inhibits the oxidative burst by neutrophils. While the functional significance of most SCP/TAPS proteins is still unknown, they deserve detailed curation and investigation, given that they have been explored as vaccine candidates for other nematodes. Although not yet curated, SCP/TAPS genes are expanded in N. americanus compared with some other parasitic nematodes of animals studied to date. One representative, Na-ASP-2, has been tested in humans as a vaccine candidate, but induced allergic responses following natural exposure to hookworm. The crystal structure of NaASP-2 reveals charge segregation, like that of mammalian chemokines, suggesting that this protein is a ligand or agonist of selected GPCRs . Another set of molecules likely to be PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/1985460 involved in host-parasite interactions are TTL proteins, 64 of which were ES proteins and 28 were transcribed only in parasitic stages of O. dentatum. TTLs are relatively conserved, and some are enzymes that catalyze the h.Cantly higher than when compared against all genes with specific transcription in parasitic and free-living stages, respectively. These findings suggest that, while most ES proteins are deployed during the lifecycle, a considerable number are specifically associated with particular functions in either the parasitic- or free-living stages of the worm. A total of 162 genes were predicted to encode ES proteins likely to have immunomodulatory or immunogenic functions, many of which were transcribed at high levels in both parasitic stages; 27% of them are `over-transcribed’ in parasitic stages. Conspicuous were transcripts encoding numerous peptidases, SCP/Tpx-1/Ag5/PR-1/Sc7, transthyretin-like and FAR binding proteins as well as eicosanoids. A set of 160 genes was inferred to encode ES peptidases in the L4 and adult stages with abundant transcription. These genes encoded mainly cysteine-type, serine-type and metallopeptidases as well as some aspartate- and threoninetype peptidases. In addition, transcription of genes encoding 75 peptidase inhibitors was assessed. Many secreted peptidases likely to represent the `degradome’ and respective inhibitors are known to enable parasitic worms to invade, penetrate tissue barriers and feed; some of them have been reported to induce or modulate the host’s immune response against the parasite. A large repertoire of genes encoding SCP/TAPS proteins was predicted; these molecules are characterized by the presence of SCP-like domains. Of the 284 predicted SCP/TAPS proteins, 167 were inferred to be ES molecules and 119 were transcribed exclusively in the parasitic stages as compared with only 19 transcribed exclusively Biotechnol Adv. Author manuscript; available in PMC 2016 November 01. Tyagi et al. Page 9 in free-living stages. In total, 179 of the predicted SCP/TAPS proteins did not have orthologs in H. contortus, N. americanus or C. elegans, and only 16 had C. elegans orthologs, similar to recent observations in Necator. The large number of genes encoding SCP/TAPS proteins in O. dentatum compared with only 34 such genes in C. elegans suggests that many of these proteins are involved in functions specific to O. dentatum, with potential relevance to parasitism and/or disease. Some of the SCP/ TAPS proteins predicted were classified as NIFs, 30 of which were predicted to be ES proteins with immunobiological roles. Although NIFs had not been reported previously for O. dentatum, the SCP-1 homolog in Ancylostoma caninum binds the canine integrin CR3 and inhibits the oxidative burst by neutrophils. While the functional significance of most SCP/TAPS proteins is still unknown, they deserve detailed curation and investigation, given that they have been explored as vaccine candidates for other nematodes. Although not yet curated, SCP/TAPS genes are expanded in N. americanus compared with some other parasitic nematodes of animals studied to date. One representative, Na-ASP-2, has been tested in humans as a vaccine candidate, but induced allergic responses following natural exposure to hookworm. The crystal structure of NaASP-2 reveals charge segregation, like that of mammalian chemokines, suggesting that this protein is a ligand or agonist of selected GPCRs . Another set of molecules likely to be PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/1985460 involved in host-parasite interactions are TTL proteins, 64 of which were ES proteins and 28 were transcribed only in parasitic stages of O. dentatum. TTLs are relatively conserved, and some are enzymes that catalyze the h.