Submitted to: Proceedings of Southern Conference on Avian Diseases
Publication Type: Abstract only
Publication Acceptance Date: 11/12/2004
Publication Date: 1/25/2005
Citation: Petkov, D.I., Kapczynski, D.R., Sellers, H.S. 2005. Evaluation of the immunological response to ibdv by flow cytometry and elisa. In:Proceedings of Southern Conference on Avian Diseases, January 24-25, 2005, Atlanta, Georgia. p.34. Interpretive Summary:
Technical Abstract: Infectious bursal disease virus (IBDV) is responsible for a highly contagious and immunosuppressive disease. Humoral immunity plays an essential role in protection against IBDV. Titers of neutralizing antibodies and levels of protection are closely related. The hypothesis of this study was that since IBDV infects immature IgM+,B-cells then different populations of IgA, IgG, and IgM expressing B-cell lymphocytes will be affected, which will affect the immunoglobulin levels in serum. The objective of this experiment was to show that changes in B-cell subpopulations occur and identify the changes in infected versus noninfected birds between 3-38 days of age (d.o.a.) in the bursa, blood, and spleen. Specific pathogen free (SPF) leghorns were inoculated with tissue-culture adapted Edgar IBDV (102.1/TCID50) at three days of age. Spleen and bursa were taken every seven days, single cell suspensions were stained with monoclonal IgA, IgM, or IgG antibodies and measured by Flow cytometry (FL). Results showed IgM+ B-cells constitute two distinct sub-populations (A and B). Population A increased from 22% at 3 d.o.a. to 40% at 38 d.o.a. while population B decreased from 50% at 3 d.o.a. to 30% at 38 d.o.a. IgA+ cells increased at 10 d.o.a. in the bursa. IgG+ cells increased between 10 and 17 days post inoculation (PI). No significant changes were observed in the spleen. Specific anti-IBDV ELISA titers increased slightly at 10 days PI, peaked around 24 days and decreased below detectable levels at 38 days PI. Total serum IgA, IgG, IgM was evaluated using ELISA. In the infected group, IgG decreased between 24-38 days, IgA increased between 17-31 days, and IgM increased between 17-38 days after inoculation. Flow cytometry analysis combined with ELISA results showed an increase in total IgA, IgM and anti-IBDV titers in serum from the infected group. The major difference detected was observed in IgM+, B-cells in the bursa.