Abstract:

【Objective】 The aim of this study was to investigate the effect of AvBD13 on the humoral immune response of chicken. 【Method】 In the treatment group chickens received drinking water supplemented with AvBD13 (1 μg?ml-1) right after hatching. Samples of blood, bursa of Fabricus, spleen and intestine were taken at day 1, 4, 7, 10 and 17 of experiment. B lymphocyte proliferation in peripheral blood stimulated by mitogen,the content of immunoglobulin in serum, antibody-forming cells in immune organ and intestine were measured by MTT, ELISA or immunohistochemistry methods. 【Result】 AvBD13 supplementation enhanced the content of IgG and IgM in serum from day 4-10 and day 10-17, respectively (P＜0.05), IgM-forming cells in bursa of Fabricus and spleen at the age of 4-7 days (P＜0.05). In addition, AvBD13 could slightly enhance the number of IgM-forming cells and IgG-forming cells in intestine at day 4 to 10, but had no significant difference (P＞0.05), AvBD13 only enhanced the cecal tonsils diffuse area IgA-forming cells at day 4 (P＜0.05). 【Conclusion】 These results suggested that AvBD13 could greatly enhance systemic humoral immune responses and slightly enhance mucosal humoral immune responses, which maybe the reason of tissue specific effect of defensins.

Key words: chicken, defensins, AvBD13, humoral immune