Innate immune response of mammary gland induced by intramammary infusion of Bifidobacterium breve in lactating dairy cows

[摘要] This study aimed to evaluate innate immune responses of mammary glands induced by intramammary infusion of Bifidobacterium breve in dairy cows. Somatic cell counts in quarters of cows showed a marked increase following B. breve infusion on days 1 and 2. Opsonized-stimulated chemiluminescence response in quarter milk was significantly ( P <0.05) increased by B. breve infusion on days 1 to 3 compared to that of pre-infusion. Lactoferrin concentrations in B. breve -infused quarter milk increased significantly ( P <0.05) on days 2 to 4 and 6 compared to those of pre-infusion. IgG and IgA concentrations in B. breve -infused quarters significantly ( P <0.05) increased on days 2 to 4 for IgG and days 3, 4, 6 and 8 for IgA compared to those of pre-infusion. Interleukin (IL)-1β and IL-8 mRNA levels in somatic cells from B. breve -infused quarters were significantly ( P <0.05) upregulated on day 1 compared to those on days 0 and 14. Conversely, IL-6 mRNA levels in somatic cells from B. breve -infused quarters on days 0, 1 and 14 and NF- κ B mRNA levels on day 0 were significantly ( P <0.05) down-regulated compared to those of control. IL-1β, tumor necrosis factor (TNF)-α and IL-6 concentrations increased on days 1, 3 and 7 after B. breve infusion in quarters. Intramammary infusion of B. breve (3 × 10 9 cfu) induces a massive influx of leukocytes and enhances innate immune response in mammary glands. This event may contribute to the enhancing host defense in the mammary gland.

[学科分类] 兽医学

[关键词] Bifidobacterium breve;dairy cow;innate immunity;intramammary infusion