IN VITRO EVALUATION OF A CHIMERIC PCV1-2 CONSTRUCT IN PORCINE KIDNEY CELLS

Porcine Circoviruses (PCVs) are small, nonenveloped viruses belonging to the genus Circovirus within the family Circoviridae.These viruses are characterized by a circular, single-stranded DNA genome of approximately 1,766 to 1,768 nucleotides [1], comprising two major open reading frames (ORFs).ORF1 encodes replication-associated proteins essential for viral replication, while ORF2 encodes the immunogenic capsid (Cap) protein, which plays a critical role in capsid assembly, host cell attachment, and eliciting the host immune response [2].Among the known PCV types, Porcine Circovirus Type 2 (PCV2) is recognized as a major pathogen in global swine production, associated with a spectrum of syndromes collectively referred to as Porcine Circovirus Diseases (PCVD) or Porcine Circovirus-Associated Diseases (PCVAD) [3].These include respiratory ABSTRACT: Porcine circovirus type 2 (PCV2) is a major causative agent of porcine circovirus-associated disease (PCVAD), responsible for significant financial losses in the swine sector.Despite the availability of commercial vaccines globally, India lacks an affordable indigenous PCV2 vaccine, with most preventive immunization dependent on imported formulations.In this study, we developed and characterized a novel chimeric PCV1-2 construct by fusing the replication-associated ORF1 of non-pathogenic PCV1 with the capsid-encoding ORF2 of PCV2.The rescued recombinant virus was successfully propagated in a subclone of porcine kidney cells, demonstrated productive replication across passages, as evidenced by gene-specific PCR, increasing capsid antigen detection by indirect ELISA (one-way ANOVA, p<0.05), immunofluorescence, and partial sequencing of ORF1/ORF2 confirmed the expected chimeric identity.These in vitro data indicate that the PCV1-2 construct is functional in porcine cells and suitable for further evaluation as a basis for developing an indigenous, low-cost approach to PCV2 control.