Development of dog mammary tumor xenograft in immunosuppressed Swiss albino mice.

Development and study of dog mammary tumour xenograft in immunosuppressed Swiss Albino Mice adds a new dimension in cancer research as dog tumors have many similarities with human tumors regarding progression, histopathology, molecular mechanism, immune response and therapy. Failure of the immune system to recognize and eliminate cancer cells leads to cancer progression and the fight between immune cells and cancer cells has a great role in understanding the mechanism of cancer progression and elimination. Rejection and acceptance of tumour xenograft depends on efficiency of CD4+, CD8+ and NK cell populations. In the present investigation, dog mammary tumor xenograft in cyclosporine-A and γ-irradiated, immunosuppressed Swiss Albino mice was developed and the immune cell status of graft accepted and rejected mice was assessed. It was observed that all the major immune cells (CD4+, CD8+ and NK cells) play an equal role in tumour rejection.

Characterization and in vitro expression of non-structural 1 protein of canine parvovirus (CPV-2) in mammalian cell line.

Parvoviruses are small, 260-Å-diameter, icosahedral, non-enveloped, single-stranded DNA viruses with a genome of approximately 5 kb. Non structural protein, (NS-1) is especially relevant, being both essential for virus replication and the main factor responsible for virus pathogenicity and cytotoxicity. This protein has also been reported to possess the property of killing of transformed cells. The present study was carried out to clone, characterize and express the NS-1 gene of canine parvovirus. NS-1 complete CDS 2020bp was amplified, cloned into eukaryotic expression vector pcDNA 3.1(+), sequenced and characterized by in vitro expression analysis. Functional activity of recombinant construct, pcDNA.cpv.NS-1, was evaluated by RT-PCR and flow cytometry for the expression of NS-1 specific mRNA and NS-1 protein, respectively, in transfected HeLa cells. This recombinant plasmid may serve as an important tool to evaluate the apoptotic potential of NS-1 protein of canine parvovirus in cultured HeLa cells.