title: In ovo injection of anti-chicken CD25 monoclonal antibodies depletes CD4+CD25+ T cells in chickens.
abstract: The CD4(+)CD25(+) cells have T regulatory cell properties in chickens. This study investigated the effect of in ovo injection of anti-chicken CD25 monoclonal antibodies (0.5 mg/egg) on CD4(+)CD25(+) cell depletion and on amounts of interleukin-2 mRNA and interferon-γ mRNA in CD4(+)CD25(-) cells posthatch. Anti-chicken CD25 or PBS (control) was injected into 16-d-old embryos. Chicks hatched from eggs injected with anti-chicken CD25 antibodies had a lower CD4(+)CD25(+) cell percentage in the blood until 25 d posthatch. The anti-chicken CD25 antibody injection nearly depleted CD4(+)CD25(+) cells in the blood until 16 d posthatch. At 30 d posthatch, the CD4(+)CD25(+) cell percentage in the anti-CD25-antibody-injected group was comparable with the percentage in the control group. At 16 d posthatch, the anti-chicken CD25 antibody injection decreased CD4(+)CD25(+) cell percentages in the thymus, spleen, and cecal tonsils. Chickens hatched from anti-CD25-antibody-injected eggs had approximately 25% of CD4(+)CD25(+) cells in the cecal tonsils and thymus compared with those in the cecal tonsils and thymus of the control group. The CD4(+)CD25(-) cells from the spleen and cecal tonsils of chicks hatched from anti-chicken-CD25-injected eggs had higher amounts of interferon-γ and interleukin-2 mRNA than CD4(+)CD25(-) cells from the control group. It could be concluded that injecting anti-chicken CD25 antibodies in ovo at 16 d of incubation nearly depleted the CD4(+)CD25(+) cells until 25 d posthatch.
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster 44691, USA.
authors.forename: Revathi
authors.initials: R
authors.lastname: Shanmugasundaram
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Selvaraj
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002642:Chick Embryo; D002645:Chickens / Q000276:immunology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D008212:Lymphocyte Depletion; D010063:Ovum
chemical_list: D000911:Antibodies, Monoclonal; D053645:Interleukin-2 Receptor alpha Subunit