Application of Trichinella Papuae Crude Antigen in Immunodiagnosis of Human Trichinellosis Papuae and Identification of Immunodominant Antigens

Abstract

Immunodiagnosis of human trichinellosis papuae by indirect ELISA and immunoblot was developed using Trichinella papuae muscle L1 larva crude worm antigens (TpaL1-CWA) and tested with human sera of trichinellosis papuae (n = 18), healthy control (n = 26) and other parasitic diseases (n = 160). IgG2- and IgG3-indirect ELISAs failed to elicit positive results, total IgG-, IgG1- and IgG4-ELISAs demonstrated sensitivity of 100, 100 and 66.7%, respectively and specificity of 90.3, 89.8 and 66.7%, respectively. Western blotting of TpaL1-CWA revealed predominant immunoreactive antigens of 31, 45 and 66.2 kDa against total IgG and IgG1 of trichinellosis papuae sera, which, except for 31 kDa antigen, showed cross-reactivity with sera of several other parasitic diseases. Specificity, sensitivity, positive predictive value, and negative predictive value of T. papuae 31 kDa in IgG1-immunoblot were 100%. Mass spectrometry analysis of the 31 kDa antigen revealed the presence (in decreasing order of identity score) of 3-hydroxyacyl-CoA dehydrogenase, GLIPR1-like protein 1, tissue-type plasminogen activator, hypothetical protein T10_8058, and hypothetical protein T10_12289. Future studies should focus on evaluating the most appropriate candidate 31 kDa antigen to prepare recombinant protein for application in trichinellosis papuae immunodiagnosis