Induction of cell-mediated immunity to Staphylococcus aureus in the mouse mammary gland by local immunization with a live attenuated mutant.
The efficacy of intramammary (Ima) immunization with a live attenuated (la) Staphylococcus aureus mutant to protect the mouse mammary gland from infection has previously been established. The present study was aimed at evaluating whether Ima immunization with la-S. aureus can induce cell-mediated immune responses to the pathogen within the mammary gland. Mice were immunized by Ima route with la-S. aureus, and regional lymph node mononuclear cells were obtained thereafter. A higher expression of the interleukin-2 receptor was found on B and T cells from immunized mice when they were compared with control mice. Immunization with la-S. aureus induced strong proliferative responses to S. aureus. Moreover, significantly increased levels of gamma interferon (IFN-gamma) were produced by CD4+ T cells when lymphocytes from immunized mice, but not from control mice, were cultured in the presence of staphylococcal antigens. Moreover, a significant increase in the percentage of IFN-gamma-producing CD4+ and CD8+ T cells was observed after S. aureus Ima challenge in immunized mice compared to challenged control mice. Our results demonstrated that Ima immunization with la-S. aureus induced primed lymphocyte populations capable of responding against staphylococcal antigens during in vitro stimulation, as well as during in vivo infection by S. aureus. CD4+ and CD8+ T cells appear to be the main lymphocyte subpopulations involved in this response. It is suggested that IFN-gamma production induced by Ima immunization may play a pivotal role in the eradication of intracellular staphylococci.
Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Marisa I
MI
Gómez
Daniel O
DO
Sordelli
Fernanda R
FR
Buzzola
Verónica E
VE
García
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001940:Breast / Q000166:cytology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000382:microbiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000382:microbiology; D002478:Cells, Cultured; D005260:Female; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D015847:Interleukin-4 / Q000096:biosynthesis / Q000276:immunology; D051379:Mice; D016296:Mutagenesis; D013203:Staphylococcal Infections / Q000276:immunology* / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology; D014611:Vaccination; D014613:Vaccines, Attenuated
D014613:Vaccines, Attenuated; D015847:Interleukin-4; D007371:Interferon-gamma