Hernandez A., Karrow N., Wilkie B.N., Mallard B.A..
2002. Evaluation of delayed-type hypersensitivity (DTH) and antibody response to ovalbumen (OVA) as a means to identify high and low immune responsiveness of cattle : microarray analysis of gene expression associated with high and low immune response phenotypes..
In : Second international symposium on Candidate Genes for Animal Health (C.G.A.H), Montpellier, France, August 16-18th 2002 : abstracts. CIRAD, INRA
Note générale : Session 2 : Mechanisms of defence against infections
Résumé : An immune response (IR) index to identify dairy cows with high (H) and low (L) antibody-mediated immune responses (AMIR) had been previously devised. High AMIR associated with decreased mastitis and improved response to vaccination. Measurement of cell-mediated immune response (CMIR) was not included in the index; therefore various antigen/adjuvant combinations were evaluated as inducers of DTH as indicators of CMIR to be added to the IR-index. The Bacillus Calmette Guèrin (BCG) induced/purified protein derivative (PPD) ellicited tuberculin skin test is a reliable measure of DTH; however, its use to identify livestock with high CMIR may be confounded due to previous exposure to Mycobacteria tuberculosis. DTH to BCG/PPD was therefore compared with that induced by Mycobacteria phlei (a saprophyte) and its derivative phlein as the test antigen. Adjuvants tested included Freund=s Complete Adjuvant (FCA), non-ulcerative Freund=s adjuvant (NUFA), complete NUFA and Mycobacteria phlei cell wall extract (MCWE). Reaction to PHA mitogen was also evaluated. Experimentally induced antibody response to OVA was evaluated with DTH in each treatment group of 5 cows. Results indicated that BCG/PPD and M. phlei/phlein treatments induced similar DTH with peak reactions at - 48 hours after intradermal antigen injection and that there was substantial variation in DTH between cows. Antibody response to OVA was also similar. Cows could be ranked for both AMIR and CMIR. The NUFA and MCWE treatments induced fewer granulomas than FCA or cNUFA. The change in skin thickness response to PHA peaked at 6 hours, had leukocyte infiltration similar to other treatments, but significantly fewer lymphocytes, based on skin biopsies taken from DTH test sites. It was generally concluded that M. phlei/phlein and BCG/PPD induced similar DTH, but that cross reaction to PPD was evident following induction of DTH using M. phlei making it a less than ideal alternative for testing livestock. To detect possible genetic differences between H and L, RNA from blood lymphocytes of cows with the highest and lowest IR ranks above were reverse transcribed. Typically, 8-10 :g of Qiagen purified total RNA was used in a 40:1 RT reaction volume. RNA from H and L cows were fluorescently labeled with different colour fluors (Cyanine 3 and 5). Each 40:1 labeling reaction generated sufficient cDNA to probe 1 array. A Human 1.7kD microarray (Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ca) containing 1700 known genes was utilized. Initial results indicate that the expression of over 200 genes, including, STAT1, natural killer cell enhancing factor A, cathepsin S precursor, leukocyte surface antigen CD53, immunoglobulin J chain, and zinc finger proteins, differ between H and L. Evaluation of a larger number of cattle classified as H or L immune responders is required to construct accurate genetic profiles. (Texte intégral)
Mots-clés Agrovoc : expression des gènes, anticorps, vache laitière
Classification Agris : L10 - Génétique et amélioration des animaux
Auteurs et affiliations
- Hernandez A., University of Guelph (CAN)
- Karrow N., University of Guelph (CAN)
- Wilkie B.N., University of Guelph (CAN)
- Mallard B.A., University of Guelph (CAN)
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/512029/)
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