ovalbumin and Mastitis

Intramammary infusion of the antigen used to sensitize cows by the systemic route induces a local inflammation associated with neutrophil recruitment. We hypothesize that this form of delayed type hypersensitivity, which may occur naturally during infections or could be induced intentionally by vaccination, can impact the outcome of mammary gland infections. We immunized cows with ovalbumin to identify immunological correlates of antigen-specific mammary inflammation. Intraluminal injection of ovalbumin induced a mastitis characterized by a prompt tissue reaction (increase in teat wall thickness) and an intense influx of leukocytes into milk of 10 responder cows out of 14 immunized animals. The magnitude of the local inflammatory reaction, assessed through milk leukocytosis, correlated with antibody titers, skin thickness test, and production of IL-17A and IFN-γ in a whole-blood antigen stimulation assay (WBA). The production of these two cytokines significantly correlated with the magnitude of the milk leukocytosis following the ovalbumin intramammary challenge. The IL-17A and IFN-γ production in the WBA was dependent on the presence of CD4+ cells in blood samples. In vitro stimulation of peripheral blood lymphocytes with ovalbumin followed by stimulation with PMA/ionomycin allowed the identification by flow cytometry of CD4+ T cells producing either IL-17A, IFN-γ, or both cytokines. The results indicate that the antigen-specific WBA, and specifically IL-17A and IFN-γ production by circulating CD4+ cells, can be used as a predictor of mammary hypersensitivity to protein antigens. This prompts further studies aiming at determining how Th17 and/or Th1 lymphocytes modulate the immune response of the mammary gland to infection.

Topics: Animals; Cattle; CD4-Positive T-Lymphocytes; Enzyme-Linked Immunosorbent Assay; Female; Hypersensitivity, Delayed; Immunization; Inflammation; Interferon-gamma; Interleukin-17; Mammary Glands, Animal; Mastitis; Milk; Ovalbumin; Skin Tests

Nonlactating ewes were immunized with a mixture of ovalbumin and tetanus toxoid either in the hind limb, resulting in "priming" of the supramammary lymph node (group L), or in the brisket, resulting in "priming" of the precapsular lymph node (group B). Substantial systemic antibody responses were mounted in both groups. The animals were challenged by intramammary infusion of either tetanus toxoid and lipopolysaccharide (LPS) or ovalbumin and LPS, and changes in the ratios of the two antibody specificities in mammary secretions were monitored for the first 8 h of the resulting acute inflammatory episode. Following challenge with tetanus toxoid and LPS, the ratio of antitetanus toxoid-antiovalbumin in mammary secretion remained close to 1 for the first 6 h postchallenge in both group L and group B. Similarly in animals challenged with ovalbumin and LPS, the ratio of antiovalbumin-antitetanus toxoid in mammary secretion approximated 1 for the first 6 h postchallenge but increased sharply in both groups between 6 and 8 h postchallenge. Measurement of antibody in efferent supramammary lymph suggested that cells in the supramammary lymph node synthesized significant quantities of specific antibody to the infused antigen during the 8-h inflammatory episode.

Topics: Animals; Antibody Formation; Female; Fluorescent Antibody Technique; Hemagglutination Tests; Immunization; Lipopolysaccharides; Lymph Nodes; Mastitis; Ovalbumin; Pregnancy; Sheep; Tetanus Toxoid

Two groups of cows were sensitized to ovalbumin (OA) during lactation by a subcutaneous injection of OA either in Freund's complete or incomplet adjuvant; two groups of animals injected with the respective adjuvants only served as controls. Intraluminal infusion of microgram quantities of OA in uninflamed mammary glands elicited inflammation, i.e., release of leukocytes into the milk, only in the animals previously sensitized to OA. This indicates that an antigen-specific inflammatory pathway can be established in the mammary gland by parenteral sensitization. Immune-mediated release of leukocytes into the milk could not be reproduced by infusing complement fixing. OA-anti-OA complexes into the lumen of uninflamed glands of unsensitized cows.

Topics: Animals; Antibodies; Antigen-Antibody Complex; Antigens; Cattle; Female; Freund's Adjuvant; Hypersensitivity, Delayed; Lactation; Leukocytes; Macrophages; Mastitis; Milk; Ovalbumin; Pregnancy