Author
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Kehrli Jr, Marcus |
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CANNING, PETER - PFIZER, TERRE HAUTE, IN |
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Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only Publication Acceptance Date: 11/10/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The ability of recombinant human granulocyte-colony stimulatory factor alone or in combination with recombinant bovine granulocyte macrophage-colony stimulatory factor to enhance neutrophil function and prevent clinical disease following intramammary challenge with Escherichia coli was tested. Cows were randomly assigned to 3 experimental groups (saline controls, rHuG-CSF or rHuG-CSF plus rBoGM-CSF). Cytokines were given subcutaneously at 1 ug/kg of body weight for 5 consecutive days beginning 3 days postpartum; cows were challenged 3 days later in one quarter with 30 colony forming units of E. coli. Control cows developed clinical mastitis with a 1.1 C febrile response 24 h post-challenge. G-CSF-treated cows developed a 0.5 C increase in body temperature similar to control cows at 12 h post-challenge but were elevated only 0.2 C at 24 h post-challenge. Cows receiving both G-CSF and GM-CSF had a febrile response to cytokine administration 12 h post-cytokine injection and had a 1.6 C febrile response 24 h post-challenge with E. coli. Administration of G-CSF alone or in combination with GM-CSF induced a neutrophilia during treatment. Expression of CD11b on neutrophils increased after challenge for animals in both the saline and cytokine combination treatment groups; however, animals treated with G-CSF alone did not. Cows receiving G-CSF alone cleared the bacterial infection by 30 h post-challenge, whereas saline controls or G-CSF + GM-CSF-treated cows did not clear the infectin until 93 and 98 h post-challenge, respectively. |
