Leukocyte populations and cytokine expression in the mammary gland in a mouse model of Streptococcus agalactiae mastitis

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Gabriela Trigo (Author) Other; Márcia Dinis (Author) Other; Ângela França (Author) Other; Elva Bonifácio Andrade (Author) Other; Rui M. Gil da Costa (Author) FEUP; Paula Ferreira (Author) ICBAS; Delfina Tavares (Author) Other

Journal

Title: Journal of Medical Microbiology

Vol. 58 No. 7

Pages: 951-958

ISSN: 0022-2615

Publisher: Microbiology Society

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 18 Citations

Other information

Authenticus ID: P-003-HWJ

DOI: 10.1099/jmm.0.007385-0

Abstract (EN): Streptococcus agalactiae is a contagious, mastitis-causing pathogen that is highly adapted to survive in the bovine mammary gland. This study used a BALB/c mouse model of Streptococcus agalactiae mastitis to evaluate leukocyte populations in regional lymph nodes and cytokine expression in the mammary gland involved in the immune response against Streptococcus agalactiae. It was found that the bacteria replicated efficiently in the mammary gland, peaking after 24 h and increasing by 100-fold. Dissemination of bacteria to systemic organs was observed 6 h after infection. At the same time, a massive infiltration of polymorphonuclear cells and an increase in the inflammatory cytokines interleukin (IL)-1 beta, IL-6 and tumour necrosis factor-alpha were detected in mammary glands, indicating an early inflammatory response. A decrease in the levels of inflammatory cytokines in mammary glands was observed 72 h after infection, accompanied by an increase in the levels of IL-12 and IL-10, which were related to a gradual decrease in bacterial load. An increase in the number of macrophages, and B220(+) lymphocytes and similar increases in both CD4(+) and CD8(+) T cells in regional lymph nodes were observed, being most pronounced 5 days after infection. Moreover, increased levels of anti-Streptococcus agalactiae antibodies in the mammary gland were observed 10 days after infection. Overall, these data suggest that the host exhibits both innate and acquired immune responses in response to Streptococcus agalactiae mastitis.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8