title: Humoral response of cattle to aerosolized Micropolyspora faeni.
abstract: Calves (7) were exposed to antigens of Micropolyspora faeni by the aerosol route for 9 weeks. The humoral immune response of calves to M faeni antigens was studied; immunoglobulins (Ig) E, G1, G2, A, and M were measured weekly in serum and nasal secretions by enzyme-linked immunosorbent assay (ELISA). Intradermal injection of antigen was performed during the 6th and 9th weeks; responses were evaluated at 30 minutes, 6 to 8 hours, 24, and 48 hours after injection. Total IgE levels in serum and nasal secretions, evaluated weekly, did not show any elevation. Micropolyspora faeni-specific IgE, IgA, IgG1, and IgG2, but not IgM, were produced by calves exposed to the antigen by the aerosol route; individual variability in magnitude of the response was marked. Thirty-minute skin tests were positive for cytotropic antibody in 2 of 3 aerosol-exposed calves by the 9th week, but delayed-type reactivity was not present. The ELISA test results were compared with those from sera of saline solution aerosol-exposed calves and from a parenterally immunized calf. Comparison of isotype-specific ELISA results obtained from M faeni aerosol-exposed calves with ELISA results from calves exposed to aerosolized ovalbumin according to a similar procedure indicated inherent problems in evaluating immune responses to environmental antigens. Aerosolized M faeni elicited a substantial antibody response. In particular, it is noteworthy that antigen-specific IgE responses were detected.
mesh_terms: D000336:Aerosols; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000276:immunology*; D002417:Cattle / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005779:Immunodiffusion / Q000662:veterinary; D007070:Immunoglobulin A / Q000096:biosynthesis; D007073:Immunoglobulin E / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis*; D008848:Micromonosporaceae / Q000276:immunology*; D009093:Mucus / Q000276:immunology; D009297:Nasal Mucosa / Q000378:metabolism; D010323:Passive Cutaneous Anaphylaxis; D012882:Skin Tests / Q000662:veterinary
chemical_list: D000336:Aerosols; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D007073:Immunoglobulin E