Identification and characterization of CD4+ T cell epitopes present in Trichinella spiralis paramyosin
Introduction
Trichinellosis is a widespread food-borne zoonosis found throughout the world, and the parasitic nematode Trichinella spiralis is one of the most common etiologic agents of this disease. As infected pork is the major source of infection in China (Cui and Wang, 2011), development of a transmission-blocking vaccine to prevent swine infection would be a practical contribution to disease control. A subunit vaccine based on multiple protective epitopes of several vaccine antigens may have many advantages compared to whole-protein antigens. Because CD4+ T cells play a crucial role in effective immunity against T. spiralis infection, identifying CD4+ T cell epitopes of vaccine antigens is crucial to construct a chimeric subunit epitope vaccine.
Our previous studies have shown that recombinant Ts-Pmy protein (rTs-Pmy) is a good vaccine candidate that induces protective immunity, with muscle larvae reduction from 33.7% to 36.7% in BALB/c mice against challenge with T. spiralis larvae (Yang et al., 2010, Yang et al., 2008). In the present study, CD4+ T cell epitopes of Ts-Pmy were predicted using an in silico algorithm, and twelve epitopes with the highest scores were synthesized as peptides. The efficacy of these synthesized peptides was determined by stimulating lymphocytes from mice immunized with rTs-Pmy or with individual peptides and assessing the immunogenicity of the epitopes based on their ability to induce Th1 or Th2 responses. This study will facilitate the design of an effective epitope-based subunit vaccine against Trichinella infections.
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Materials and methods
Based on the BALB/c mouse model, H-2d restricted CD4+ T cell epitopes (I-Ad and I-Ed) of Ts-Pmy were predicted using the SYFPEITHI database. Seven I-Ad and five I-Ed restricted epitopes predicted with the highest scores (Table 1) were synthesized as peptides by the AVIVA Systems Biology Company (Beijing, China). Six-seven week-old female BALB/c mice were subcutaneously immunized with 25 μg of rTs-Pmy or individual peptide emulsified with the adjuvant ISA50 V2 (SEPPIC, France), then boosted twice
Results and discussion
For the identification of CD4+ T cell epitopes on Ts-Pmy in vitro, splenocytes were isolated from mice immunized with rTs-Pmy and stimulated individually with the selected 12 epitope peptides. The T cell proliferation results showed that candidate epitope peptides P2, P3, P4, P5 and P12 stimulated the highest levels of proliferation similar to rTs-Pmy compared to other candidate peptides (Fig. 1, p < 0.01). The results of the ELISPOT assay demonstrated that the Th2 cytokine IL-4 and IL-5 levels
Conflict of interest
No financial or personal relationships are maintained with other people or organizations that could inappropriately influence or bias this paper.
Acknowledgement
This work was supported by grants from the National Natural Science Foundation of China (81572015, 81371837, 81201312).
References (10)
- et al.
An epidemiological overview of swine trichinellosis in China
Vet. J.
(2011) - et al.
A West Nile virus CD4 T cell epitope improves the immunogenicity of dengue virus serotype 2 vaccines
Virology
(2012) - et al.
Epitope-based vaccines: an update on epitope identification: vaccine design and delivery
Curr. Opin. Immunol.
(2003) - et al.
Genetic linkage of autologous T cell epitopes in a chimeric recombinant construct improves anti-parasite and anti-disease protective effect of a malaria vaccine candidate
Vaccine
(2010) - et al.
Identification and characterization of protective epitope of Trichinella spiralis paramyosin
Vaccine
(2011)
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