Immunogenicity of two FMDV nonameric peptides encapsulated in liposomes in mice and the protective efficacy in guinea pigs

• Published in: PloS one 2013-07, Vol.8 (7), p.e68658-e68658
• Main Authors: Gao, Feng-Shan, Feng, Lei, Zhang, Qiang, Yan, Ruo-qian, Li, Yun-Gang, Li, Xin-sheng
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antigenic determinants; Assaying; Biological response modifiers; Biology; Blood; Capsid protein; Capsid Proteins - chemistry; Capsid Proteins - immunology; CD8 antigen; Cell proliferation; Cytotoxicity; Encapsulation; Epitopes; Epitopes, T-Lymphocyte - chemistry; Epitopes, T-Lymphocyte - immunology; Female; Foot & mouth disease; Foot-and-Mouth Disease - immunology; Foot-and-Mouth Disease - metabolism; Foot-and-Mouth Disease - pathology; Foot-and-Mouth Disease - prevention & control; Foot-and-Mouth Disease Virus - immunology; Guinea Pigs; Immunization; Immunogenicity; Immunology; Interferon; Interferon-gamma - immunology; Interferon-gamma - metabolism; ISCOMS; Leukocytes (mononuclear); Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - metabolism; Liposomes; Lymphocytes; Lymphocytes T; Male; Medicine; Mice; Peptides; Peptides - chemistry; Peptides - immunology; Peripheral blood mononuclear cells; T cell receptors; T cells; T-Lymphocyte Subsets - immunology; Vaccines; Veterinary Science; Viral proteins; Viral Vaccines - immunology; Viruses; VP1 protein; Wildlife conservation; γ-Interferon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0068658

It has been predicted that nonameric peptides I (VP1(26-34), RRQHTDVSF), II (VP1(157-165), RTLPTSFNY) and III (VP1(45-53), KEQVNVLDL) from the VP1 capsid protein of the foot-and-mouth disease virus (FMDV) are T cell epitopes. To investigate whether these peptides have immunological activity, BALB/c mice were immunized with peptide I, II or III conjugated with immunostimulating complexes (ISCOMs). A cytotoxic T lymphocyte assay was used to evaluate the cytotoxic activity induced by peptides along with by measuring peptide-specific T-cell proliferation and CD8(+) T lymphocyte numbers in whole blood and interferon (IFN)-γ production in peripheral blood mononuclear cells induced by peptides. To further identify the protective efficacy of peptides, an FMDV challenge assay was done in guinea pigs. Peptides I and II stimulated significant increases in T-cell proliferation, CD8(+) T lymphocytes, and IFN-γ secretion and cytotoxic activity compared to controls. The FMDV challenge assay indicated peptides I and II can protect over 60% of animals from virus attack. The results demonstrate that peptides I and II encapsulated in liposomes should be CTL epitopes of FMDV and can protect animals from virus attack to some extent.