Mohd Yaqoob Wani

Development of a DNA vaccine for chicken infectious anemia and its immunogenicity studies using high mobility group box 1 protein as a novel immunoadjuvant indicated induction of promising protective immune responses.

Chicken infectious anaemia (CIA) is an economically important and emerging poultry disease reported worldwide. Current CIA vaccines have limitations like, the inability of the virus to grow to high titres in embryos/cell cultures, possession of residual pathogenicity and a risk of reversion to virulence. In the present study, a DNA vaccine, encoding chicken infectious anaemia virus (CIAV) VP1 and VP2 genes, was developed and co-administered with truncated chicken high mobility group box 1 (HMGB1ΔC) protein in young chicks for the evaluation of vaccine immune response. CIAV VP1 and VP2 genes were cloned in pTARGET while HMGB1ΔC in PET32b vector. In vitro expression of these gene constructs was evaluated by Western blotting. Further, recombinant HMGB1ΔC was evaluated for its biological activity. The CIAV DNA vaccine administration in specific pathogen free chicks resulted in moderately protective ELISA antibody titres in the range of 4322.87 ± 359.72 to 8288.19 ± 136.38, increased CD8(+) cells, and a higher titre was observed by co-administration of novel adjuvant (HMGB1ΔC) and booster immunizations. The use of vaccine with adjuvant showed achieving antibody titres nearly 8500, titre considered as highly protective, which indicates that co-immunization of HMGB1ΔC may have a strong adjuvant activity on CIAV DNA vaccine induced immune responses. The able potential of HMGB1 protein holding strong adjuvant activity could be exploited further with trials with vaccines for other important pathogens for achieving the required protective immune responses.

Impact of virus load on immunocytological and histopathological parameters during clinical chicken anemia virus (CAV) infection in poultry.

Chicken anemia virus (CAV) is one the important pathogen affecting commercial poultry sector globally by causing mortality, production losses, immunosuppression, aggravating co-infections and vaccination failures. Here, we describe the effects of CAV load on hematological, histopathological and immunocytochemical alterations in 1-day old infected chicks. The effects of CAV on cytokine expression profiles and generation of virus specific antibody titer were also studied and compared with viral clearance in various tissues. The results clearly confirmed that peak viral load was achieved mainly in lymphoid tissues between 10 and 20 days post infection (dpi), being highest in the blood (log1010.63 ±0.87/ml) and thymus (log1010.29 ±0.94/g) followed by spleen, liver, bone marrow and bursa. The histopathology and immunoflowcytometric analysis indicated specific degeneration of T lymphoid cells in the thymus, spleen and blood at 15 dpi. While the transcript levels of interleukin (IL)-1, IL-2, IL-12 decreased at all dpi, interferon (IFN)-γ increased (3-15 fold) during early stages of infection and the appearance of virus specific antibodies were found to be strongly associated with virus clearance in all the tissues. Our findings support the immunosuppressive nature of CAV and provide the relation between the virus load in the various body tissues and the immunopathological changes during clinical CAV infections.

A novel recombinant Meq protein based dot-ELISA for rapid and confirmatory diagnosis of Marek’s disease induced lymphoma in poultry

Mareks disease (MD), is an economically important virus disease of poultry throughout the world. In this study, we for the first time reports development of a novel dot enzyme-linked immunosorbent assay (dot-ELISA) for the confirmatory diagnosis of lymphoma caused by Mareks Disease Virus (MDV). Suspected lymphoma tissue extracts from the diseased birds were used for the Meq oncoprotein antigen detection, which is expressed specifically in MDV lymphomas. Recombinant Meq oncoprotein was expressed using Expresso™ Rhamnose Sumo Cloning and Expression system and the hyperimmune serum was raised against it, which was used later while developing dot-ELISA. The dot-ELISA exhibited higher specificity (92%) in diagnosing MD lymphomas as compared to conventional PCR (40%), where later assay is unable to differentiate disease development (lymphoma) and/or infection. The developed dot-ELISA proved to be a specific, rapid and inexpensive technique detecting MDV lymphomas in poultry. Of the note, this new assay could be opted as a valuable diagnostic tool in the resource poor countries andcould further be used to differentiate from other tumor causing viruses in poultry.