Gene expression profiles of antigenic proteins of third stage larvae of the zoonotic nematode Anisakis pegreffii in response to temperature conditions

Abstract

Anisakis pegreffii, a recognised etiological agent of human anisakiasis, is a parasite of homeothermic hosts at the adult stage and of ectothermic hosts at the third larval stage. Among distinct factors, temperature appears to be crucial in affecting parasite hatching, moulting and to modulate parasite-host interaction. In the present study, we investigated the gene transcripts of proteins having an antigenic role among excretory secretory products (ESPs) (i.e., a Kunitz-type trypsin inhibitor, A.peg-1; a glycoprotein, A.peg-7; and the myoglobin, A.peg-13) after 24 h, in A. pegreffii larvae maintained in vitro, under controlled temperature conditions. Temperatures were 37 °C and 20 °C, resembling respectively homeothermic and ectothermic hosts conditions, and 7 °C, the cold stress condition post mortem of the fish host. Primers of genes coding for these ESPs to be used in quantitative real-time PCR were newly designed, and qRT-PCR conditions developed. Expression profiles of the genes A.peg-1 and A.peg-13 were significantly up-regulated at 20 °C and 37 °C, with respect to the control (larvae kept at 2 °C for 24 h). Conversely, transcript profiles of A.peg-7 did not significantly change among the chosen temperature conditions. In accordance with the observed transcript profiles, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of the three target ESPs at 37 °C, while only A.peg-13 was observed at 7 °C. The results suggest that temperature conditions do regulate the gene expression profiles of A.peg-1 and A.peg-13 in A. pegreffii larvae. However, regulation of the glycoprotein A.peg-7 is likely to be related to other factors such as the host’s immune response.

Advances in Omic Studies Drive Discoveries in the Biology of Anisakid Nematodes

“…Temperature is a recognized factor that is implicated in adaptive processes in aquatic parasites, which perform larval molting or hatching in a temperature-dependent way and are induced to hypometabolism by cold temperatures [ 45 ]. Three proteins with antigenic roles among excretory secretory products, in particular the antigens A.peg-1 (Kunitz serine protease inhibitor), A.peg-7 (armadillo-like helical), and A.peg-13 (globin), have been studied in A. pegreffii via the evaluation of expression profiles under controlled temperatures simulating homeothermic and ectothermic hosts conditions [ 46 ]. While the A.peg-7 expression profiles did not significantly change among the different temperature conditions, A.peg-1 and A.peg-13 expression profiles were significantly higher at 20 °C and 37 °C, respectively.…”

Comparative Proteomics Analysis of Anisakis simplex s.s.—Evaluation of the Response of Invasive Larvae to Ivermectin

“…Additionally, Kunitz inhibitor protease, trypsin inhibitor-like protein (TIL), and ShKT domain-containing protein could play important roles in the immunomodulation of host antiparasitic immunological responses. The Kunitz-type trypsin inhibitor (Ani s1) has an antigenic role among excretory‒secretory products [ 55 , 56 ]. The ShKT domain, which has also been called a nematode six-cysteine (NC6) domain [ 57 ] and ion channel regulator (ICR) [ 58 ] in venomous creatures, has likely been modified to give rise to potent ion channel blockers.…”

Cross-species utility of microsatellite loci for the genetic characterisation ofAnisakis berlandi(Nematoda: Anisakidae)

“…Finally, in a multi-nuclear genotyping approach, SSR markers provide a powerful means to investigate, including also SNP polymorphisms detected in other nuclear genes [7,18], the detection of possible patterns of hybridisation/introgression events between the three species of the A. simplex (s. l.) complex, in sympatric areas and syntopic conditions [9].…”