The identification of a sequence related to apicomplexan enolase from Sarcocystis neurona

Proteomic analysis of differentially expressed proteins in the marine fish parasitic ciliate Cryptocaryon irritans

Cryptocaryoniasis is a severe disease of farmed marine fish caused by the parasitic ciliate Cryptocaryon irritans. This disease can lead to considerable economic loss, but studies on proteins linked to disease development and antigenic proteins for vaccine development have been relatively scarce to date. In this study, 53 protein spots with differential abundance, representing 12 proteins, were identified based on a pair-wise comparison among theronts, trophonts, and tomonts. Meanwhile, 33 protein spots that elicited serological responses in rabbits were identified, representing 9 proteins. In addition, 27 common antigenic protein spots reacted with grouper anti-sera, representing 10 proteins. Most of the identified proteins were involved in cytoskeletal and metabolic pathways. Among these proteins, actin and α-tubulin appeared in all three developmental stages with differences in molecular weights and isoelectric points; 4 proteins (vacuolar ATP synthase catalytic subunit α, mcm2-3-5 family protein, 26S proteasome subunit P45 family protein and dnaK protein) were highly expressed only in theronts; while protein kinase domain containing protein and heat shock protein 70 showed high levels of expression only in trophonts and tomonts, respectively. Moreover, actin was co-detected with 3 rabbit anti-sera while β-tubulin, V-type ATPase α subunit family protein, heat shock protein 70, mitochondrial-type hsp70, and dnaK proteins showed immunoreactivity with corresponding rabbit anti-sera in theronts, trophonts, and tomonts. Furthermore, β-tubulin, the metabolic-related protein enolase, NADH-ubiquinone oxidoreductase 75 kDa subunit, malate dehydrogenase, as well as polypyrimidine tract-binding protein, glutamine synthetase, protein kinase domain containing protein, TNFR/NGFR cysteine-rich region family protein, and vacuolar ATP synthase catalytic subunit α, were commonly detected by grouper anti-sera. Therefore, these findings could contribute to an understanding of the differences in gene expression and phenotypes among the different stages of parasitic infection, and might be considered as a source of candidate proteins for disease diagnosis and vaccine development.

An update on Sarcocystis neurona infections in animals and equine protozoal myeloencephalitis (EPM)

Equine protozoal myeloencephalitis (EPM) is a serious disease of horses, and its management continues to be a challenge for veterinarians. The protozoan Sarcocystis neurona is most commonly associated with EPM. S. neurona has emerged as a common cause of mortality in marine mammals, especially sea otters (Enhydra lutris). EPM-like illness has also been recorded in several other mammals, including domestic dogs and cats. This paper updates S. neurona and EPM information from the last 15 years on the advances regarding life cycle, molecular biology, epidemiology, clinical signs, diagnosis, treatment and control.

In silico approach for the identification of immunological properties of enolase from Trypanosoma cruzi and its possible usefulness as vaccine in Chagas disease

Nowadays, Chagas disease is a major health problem in Latin America that has been disseminated also into non-endemic countries. Currently, a vaccine against Chagas disease does not exist. In the present study, the gene encoding Trypanosoma cruzi enolase (TcENO) was amplified, cloned, and sequenced and the recombinant protein was purified. We used in silico and an experimental assay to investigate the immunological role of TcENO. The in silico assays showed that TcENO sequence contains characteristic motifs of enolase; additionally, a transmembranal region was identified, and this could indicate the potential membrane localization of TcENO. Moreover, both B lymphocyte and cytotoxic T lymphocytes (CTL) predicted epitopes were localized; these results suggest the possibility that TcENO can develop both humoral and cellular immune responses. Furthermore, the presence of antibodies was verified by western blot assays, showing that the purified recombinant protein was detected by sera from experimentally infected mice and sera of patients with Chagas disease. These results indicate that TcENO is immunogenic and could be used as a vaccine candidate.

Sarcocystis neurona: molecular characterization of enolase domain I region and a comparison to other protozoa

Sarcocystis neurona causes protozoal myeloencephalitis and has the ability to infect a wide host range in contrast to other Sarcocystis species. In the current study, five S. neurona isolates from a variety of sources, three Sarcocystis falcatula, one Sarcocystis dasypi/S. neurona-like isolate, and one Besnoitia darlingi isolate were used to compare the enolase 2 gene segment containing the domain I region to previously sequenced enolase genes from Neospora caninum, Neospora hughesi, Toxoplasma gondii, Plasmodium falciparum, and Trypanosoma cruzi; enolase 2 segment containing domain I region is highly conserved amongst these parasites of veterinary and medical importance. Immunohistochemistry results indicates reactivity of T. gondii enolase 1 and 2 antibodies to S. neurona merozoites and metrocytes, but no reactivity of anti-enolase 1 to the S. neurona bradyzoite stage despite reactivity to T. gondii bradyzoites, suggesting expression differences between organisms.