Studies on the antigenic relationship between turkey pox and fowl poxviruses

B.B. Dash, Alka Singh, J.M. Kataria, S. Dandapat and K. Dhama
Division of Avian Diseases, IVRI, Izatnagar, U.P.-243 122

The antigenic relationship existing between turkey pox (TPV) and fowl pox (FPV) viruses was assessed by employing indirect ELISA, SNT, dot-ELISA using homologous and heterologous polyclonal antisera raised against these viruses. The antigen relationship (R) was determined quantitatively by calculating the R- value as per the Archette's formula, which was found to be 0.57 in case of SNT and 0.95 in case of ELISA between TPV and FPV. The R-value of 0.57 by SNT reflects the antigenic unrelated ness between these two avipoxviruses, but in ELISA with R-value of 0.95 depicts the existence of antigenic relationship between TPV and FPV. Dot-ELISA and AGPT detected TPV and FPV antigens and antibodies using both homologous and heterologous sera qualitatively with low specificity and found to be unsuitable to determine the antigenic relationship between avipoxviruses. The presence of common antigens between TPV and FPV and the use of polyclonal antisera resulted in the appearance of high R- value (0.95) in case of ELISA was due to its high sensitivity and low specificity in comparison to SNT. However, SNT was found to be highly specific in determining the antigenic relationship between TPV and FPV. The protein profiles and sharing of immunogenic polypeptides between TPV and FPV were also determined by SDS-PAGE and western blotting respectively. It was reportedly confirmed that TPV and FPV are antigenically different though FPV origin vaccine may provide partial protection in turkeys against TPV infection, but neutralizing antibodies against three important immunogenic peptides of TPV (100 Kda, 94 Kda and 80 Kda) play major roles in providing proper protection to turkeys against TPV infection. Therefore, the use of a homologous vaccine is necessary for proper management of turkey poxvirus infection in turkeys.

Source : IPSACON-2005

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