Immune responses in mice vaccinated with a DNA vaccine expressing serine protease-like protein from the new-born larval stage of Trichinella spiralis

• Published in: Parasitology Vol. 144; no. 6; pp. 712 - 719
• Main Authors: XU, JING, BAI, XUE, WANG, LI BO, SHI, HAI NING, VAN DER GIESSEN, JOKE W. B., BOIREAU, PASCAL, LIU, MING YUAN, LIU, XIAO LEI
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.05.2017
• Subjects: Animal models; Animals; Antibodies, Helminth - biosynthesis; Antibodies, Helminth - blood; antibody formation; Antigens; CD4 antigen; CD4-CD8 Ratio; CD8 antigen; CD8-positive T-lymphocytes; Cloning; Coding; complementary DNA; Cytokines - biosynthesis; Cytokines - blood; Deoxyribonucleic acid; DNA; DNA vaccines; Epidemiology; Female; fluorescent antibody technique; Gene expression; Helminth Proteins - genetics; Helminth Proteins - immunology; helminthiasis; helminths; humoral immunity; Immune response; Immune response (humoral); Immune system; Immunization; Immunofluorescence; Immunoglobulin G; Immunoglobulin G - biosynthesis; Immunoglobulin G - blood; Infections; Infectious diseases; Laboratories; Larva - immunology; Larvae; Life Sciences; Lymphocytes T; Mice; muscle larvae; Parasites; Parasitism; Parasitology; plasmids; Plasmids - genetics; Plasmids - metabolism; Protease; Proteins; Public health; Rabies; Rats; Rats, Wistar; Recombinant Proteins - immunology; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; recombinant vaccines; Serine; Serine Proteases - genetics; Serine Proteases - immunology; Serine proteinase; serine proteinases; T-Lymphocytes - cytology; Trichinella spiralis; Trichinella spiralis - immunology; Trichinellosis - immunology; Trichinellosis - prevention & control; Tropical diseases; vaccination; Vaccines; Vaccines, DNA - immunology; Zoonoses; China; DNA vaccine; Trichinella spiralis; protective immunity; new-born larvae
• ISSN: 0031-1820; 1469-8161; 1469-8161
• DOI: 10.1017/S0031182016002493

Trichinella spiralis is a parasitic helminth that can infect almost all mammals, including humans. Trichinella spiralis infection elicits a typical type 2 immune responses, while suppresses type 1 immune responses, which is in favour of their parasitism. DNA vaccines have been shown to be capable of eliciting balanced CD4+ and CD8+ T cell responses as well as humoral immune responses in small-animal models, which will be advantage to induce protective immune response against helminth infection. In this study, serine protease (Ts-NBLsp) was encoded by a cDNA fragment of new-born T. spiralis larvae, and was inserted after CMV promoter to construct a DNA vaccine [pcDNA3·1(+)-Ts-NBLsp]. Ts-NBLsp expression was demonstrated by immunofluorescence. Sera samples were obtained from vaccinated mice, and they showed strong anti-Ts-NBLsp-specific IgG response. Mice immunized with the pcDNA3·1(+)-Ts-NBLsp DNA vaccine showed a 77·93% reduction in muscle larvae (ML) following challenge with T. spiralis ML. Our results demonstrate that the vaccination with pcDNA3·1(+)-Ts-NBLsp plasmid promoted the balance of type 1 and 2 immune responses and produced a significant protection against T. spiralis infection in mice.