In vivo Immunogenicity and Antigenicity of MAP-8 Peptides Derived from the Structural and Non-Structural Proteins of Canine Parvovirus Type 2

Introduction Canine parvovirus is a viral disease associated with the infection with the canine parvovirus type 2 (CPV-2). Virus-attenuated or inactivated vaccines are commonly used as prophylaxis; still, novel formats such as peptide-based vaccines are a promising alternative due to their safety and capacity to induce an adequate immune response. However, selected peptides must be evaluated in vivo to test their ability to induce immune response and potential side effects. Materials and Methods Four peptides derived from the structural and non-structural proteins of CPV-2 were chemically synthesized and used to evaluate the immunogenicity in Balb/C mice. Serum samples were collected and used for the evaluation of humoral immune response. We performed Indirect ELISA and Dot blot to detect antibodies against the peptides. Finally, to evaluate the potential side effects of peptides, we conducted a urinalysis (before sacrifice) and a complete blood count (day 200 since the first inoculation). Results From the four used peptides, we detected the presence of IgM and IgG subclasses against all the peptides. The complete blood count showed changes in the levels of hemoglobin, the count of granulocytes and lymphocytes, and the numbers and parameters of platelets between the control and experimental groups. The Dot blot confirmed the peptides’ immunogenicity and the recognition of the native antigen in the commercial vaccine. Conclusion The in vivo evaluation in Balb/c mice showed that the peptides derived from the CPV-2 are immunogenic and safe for administration, which can contribute to developing effective and safe vaccines against parvovirus.