Characterization of immunosuppressive factors in the mastitis-infected mammary gland of non-lactating cows II. Suppression of mitogen-induced lymphoblastogenesis by neutrophils from peripheral blood and mammary gland secretion

건유기 유방염 감염우의 유방내 면역저하요인 규명에 관한 연구 II. 호중구에 의한 말초혈액 및 유즙 림프구의 mitogen 유도성 증식반응 억제작용

To establish the effective ways to prevent bovine mastitis, the study has been performed to investigate the attributable factors causing down-regulation of immune responses in mammary gland of non-lactating cows. Lymphocytes from peripheral blood and mammary gland secretions(MGS) were obtained from normal healthy cows and mastitic cows, respectively. Lymphoblastogenesis were investigated carefully by adding different concentrations of supernatants collected from pure-cultures of neutrophils seperated from peripheral blood and MGS, respectively. The results obtained are as follows ; 1. Lymphoblastogenesis activity stimulated by Con A, PWM and PHA were significantly reduced in MGS from mastitic cows. 2. Supernatants collected from pure-culture of neutrophils separated both from peripheral blood and MGS showed inhibitory effect on mitogenic lymphoblastogenesis. 3. Supernatants from mammary gland neutrophils have shown 7 times more inhibitory activity than those from peripheral blood and this inhibitory effect was increased in proportion to increasing concentrations of supernatants when those were added to lymphoblast cells in culture.