Priming with rAAV encoding RBD of SARS-CoV S protein and boosting with RBD-specific peptides for T cell epitopes elevated humoral and cellular immune responses against SARS-CoV infection

Vaccine. 2008 Mar 20;26(13):1644-51. doi: 10.1016/j.vaccine.2008.01.025. Epub 2008 Feb 4.

Abstract

Development of vaccines against severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) is crucial in the prevention of SARS reemergence. The receptor-binding domain (RBD) of SARS-CoV spike (S) protein is an important target in developing safe and effective SARS vaccines. Our previous study has demonstrated that vaccination with adeno-associated virus encoding RBD (RBD-rAAV) induces high titer of neutralizing antibodies. In this study, we further assessed the immune responses and protective effect of the immunization with RBD-rAAV prime/RBD-specific T cell peptide boost. Compared with the RBD-rAAV prime/boost vaccination, RBD-rAAV prime/RBD-peptide (RBD-Pep) boost induced similar levels of Th1 and neutralizing antibody responses that protected the vaccinated mice from subsequent SARS-CoV challenge, but stronger Th2 and CTL responses. No significant immune responses and protective effects were detected in mice vaccinated with RBD-Pep or blank AAV alone. Since T cell epitopes are highly conserved and boosting with peptides may induce the production of effector memory T cells, which may be effective against viruses with mutations in the neutralizing epitopes, our results suggest that the vaccination protocol used may be ideal for providing effective, broad and long-term protection against SARS-CoV infection.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibody Formation / immunology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Coronavirus M Proteins
  • Dependovirus / genetics*
  • Dependovirus / immunology*
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes / immunology
  • Female
  • Flow Cytometry
  • Immunity, Cellular / immunology*
  • Immunization Schedule
  • Immunization, Secondary
  • Immunoglobulin G / analysis
  • Immunoglobulin G / biosynthesis
  • Mice
  • Mice, Inbred BALB C
  • Neutralization Tests
  • Receptors, Virus / genetics*
  • Receptors, Virus / immunology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Severe Acute Respiratory Syndrome / immunology
  • Severe Acute Respiratory Syndrome / prevention & control
  • Severe Acute Respiratory Syndrome / virology
  • Severe acute respiratory syndrome-related coronavirus / immunology*
  • T-Lymphocytes / immunology*
  • Vaccines, Synthetic / immunology
  • Viral Matrix Proteins / genetics*
  • Viral Matrix Proteins / immunology*
  • Viral Vaccines / immunology*

Substances

  • Coronavirus M Proteins
  • Epitopes
  • Immunoglobulin G
  • M protein, SARS-CoV
  • Receptors, Virus
  • Vaccines, Synthetic
  • Viral Matrix Proteins
  • Viral Vaccines