Suppression of Chicken Immunoglobulin Ontogeny by F(ab′)₂ Fragments of Anti-μ Chain and by Anti-L Chain

Abstract

Serum IgM, IgY and IgA were suppressed by the embryonic administration of F(ab′)₂ fragments of goat anti-μ followed by bursectomy at hatch, indicating that the Fc fragment is not essential for antibody-mediated class suppression in chickens. Anti-L chain was also capable of mediating suppression but anti-IgY H chain was not, indicating that the mechanism for suppression involves specific binding to IgM-producing cells rather than a toxic effect of antibody-antigen complexes. At the doses used, both F(ab′)₂ anti-μ and intact anti-L antibody caused more marked suppression of IgA than of IgM and IgY.

The Secretory Immunologic System of Fowl

“…Fertile DeKalb 161 White Leghorn eggs obtained locally were used in all experiments. Surgical bursectomy was performed within 18 h of the time of hatch [12,13,16].…”

“…The purification of chicken IgM, IgY, and IgA has been described [7,8,11] as has the preparation of the anti-/*, anti a, anti IgY, and F(ab')2 anti-/* [11][12][13].…”

“…The specifically purified anti-/* and F(ab')2 anti-/* were given intravenously (i. v.) on days 16-18 of embryonation [12,13], Sera were collected at various times after hatching, and the oral secretions, hereafter referred to as saliva, were collected after injecting 0.8 ml of 1% pilocar pine i. v. (Pilocar SMP; Smith, Miller & Patch, Inc., New Brunswick, N. J.).…”

“…Our method for quantitative radial immunodiffusion and its sensitivity has been described [11][12][13]16].…”

“…Studies on differentiation of the plasma cell line have shown that bursectomy has a suppressive effect on serum IgA ontogeny [4,16] and embryonic administration of either anti-/* [3,12] or F(ab')2 fragments of anti-/* [13] coupled with neonatal bursectomy severely inhibited ser um IgA synthesis. These observations led us to believe that IgA-producing cells are the descendents of IgM-precursor cells.…”