Objective: The purpose of the present in vivo study was to evaluate correlation of the virulence of the infectious bursa disease virus with the rate of apoptotic changes of the immature B lymphocytes in Bursa Fabric us (BF) and lymphoid cells of spleen.
Design: Experimental study.
Animals: 21-day-old SPF chicks of leghorn breed
Procedures: 90 chicks were divided into three groups (TEST- IBDV,TEST-VAC and Control) of 30 chicks each.
inoculation of the TEST-IBDV, TEST -VAC and Control
groups were done with IR-499 serotype of high-virulence infectious bursa disease Virus (VVIBDV), D78 intermediate vaccine and normal saline, respectively. Furthermore, 20 chicks were categorited into two groups (Test and Control) of 10 chicks each. Test and Control groups were inoculated with VVJI3DV and normal saline, respectively. 3 days after inoculation, samples of BF and splenic tissues were sent to Pathology Lab for LM, H&E sating and TUNEL studies.
Statistical analysis: Kruskal-Wallis, ANOVA and Mann- Whitney test.
Results: LM and H&E staining showed many significant differences among groups. Furthermore, we showed VP2&VP5, INF-gamma and TNF-alpha were the major inductive factors for development of apoptosis in the immature Lymphocytes of BF and spleen.
Discussion: The present in vivo research showed that there is always a significant correlation between the virulence of the virus and the rate of apoptotic changes in the BF tissue.
Moreover, apoptosis can be considered as a definite factor in
the pathogenesis of infectious bursa disease (IBD).
J.Fac. Vet.Med. Univ. Tehran. 60,4:313-320,2005.