Specific immune responses of dairy cattle after primary inoculation with recombinant bovine interferon-gamma as an adjuvant when vaccinating against mastitis.
OBJECTIVE
To examine whether specific immunity in the mammary gland and blood of dairy cattle was enhanced after primary inoculation with a test antigen keyhole limpet hemocyanin (KLH) and recombinant bovine interferon-gamma (rBoIFN-gamma) as an adjuvant.


METHODS
Holstein dairy cows received IM injections of KLH in conjunction with saline solution (n = 4), Freund's incomplete adjuvant (FIA; n = 4), or rBoIFN-gamma (n = 3). Milk and blood samples were collected during a 1-month period and analyzed for KLH antibody content. Isolated blood mononuclear cells were examined for their ability to proliferate and produce interleukin 2 (IL-2) after mitogen and/or KLH stimulation in vitro. The phenotype of isolated blood mononuclear cells also was characterized through flow cytometric analysis.


RESULTS
The adjuvant rBoIFN-gamma induced serum KLH antibody titers similar to those induced by administration of FIA. However, FIA induced significantly more KLH antibodies in milk. Administration of rBoIFN-gamma enhanced T-lymphocyte activity, as indicated by the greater expression of high-affinity IL-2 receptors and the increased response to the mitogens concanavalin A, phytohemagglutinin, and IL-2, compared with FIA or saline treatment. Lymphocyte and monocyte movement from the blood also was altered after rBoIFN-gamma treatment, which can have a profound influence on secondary immune responses, such as antibody production.


CONCLUSIONS
rBoIFN-gamma may safely enhance specific immunity in the bovine mammary gland and may be an effective adjuvant in mastitis immunization protocols.
Pighetti
G M
GM
Center for Mastitis Research, College of Agricultural Sciences, Penn State University, University Park, PA 16802-3500, USA.
Sordillo
L M
LM
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology; D002417:Cattle; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D005620:Freund's Adjuvant / Q000494:pharmacology; D006433:Hemocyanins / Q000276:immunology / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000276:immunology / Q000378:metabolism; D008414:Mastitis, Bovine / Q000276:immunology / Q000517:prevention & control*; D008934:Mitogens / Q000494:pharmacology; D010641:Phenotype; D011897:Random Allocation; D011994:Recombinant Proteins
D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D007376:Interleukin-2; D008934:Mitogens; D011994:Recombinant Proteins; D003208:Concanavalin A; D007371:Interferon-gamma; D005620:Freund's Adjuvant; D006433:Hemocyanins