title: Compartmentalization of Th1/Th2 cytokine responses to experimental Yersinia pseudotuberculosis infection in cats.
abstract: Specific pathogen-free cats were inoculated subcutaneously into the drainage areas of the left auricular and popliteal lymph nodes with living Yersinia pseudotuberculosis. Inflammation was evident at the inoculation sites and the regional lymph nodes were palpably enlarged at 48 h post-infection. Lymph node enlargement was due to marked paracortical lymphoid hyperplasia and variable neutrophil infiltrates. Yersinia was cultured from the regional lymph nodes and/or spleens of three of the six cats, indicating systemic spread of bacteria. Specific T-helper 1 and 2 (Th1, Th2) cell-associated cytokine mRNA levels were compared in regional lymph nodes, peripheral blood mononuclear cells (PBMC) and spleen at 48 h post-inoculation. Relative to unstimulated control tissues, there was a significant increase in TNF-alpha, IFN-gamma, IL-12, and IL-10 mRNAs in spleen with down-regulation of IL-4. Significant up-regulation of TNF-alpha and down-regulation of IL-4 were also observed in PBMC. Paradoxically, 48 h stimulated lymph nodes showed only minimal differences in cytokine mRNA expression when compared to lymph nodes from mock-inoculated control animals or unchallenged contralateral lymph nodes from the same animal. This study demonstrated that cats, like mice, respond to an intracellular pathogen such as Y pseudotuberculosis with a predominantly Th1-type immune response. The cytokine responses in regional lymph nodes and spleen were asynchronous, while cytokine stimulation in cells of the spleen was mirrored by PBMC.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA. antti.sukura@helsinki.fi
authors.forename: A
authors.initials: A
authors.lastname: Sukura
authors.forename: J
authors.initials: J
authors.lastname: Higgins
authors.forename: N C
authors.initials: NC
authors.lastname: Pedersen
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000276:immunology* / Q000382:microbiology; D002415:Cats; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D015011:Yersinia pseudotuberculosis / Q000276:immunology* / Q000302:isolation & purification; D015012:Yersinia pseudotuberculosis Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D016207:Cytokines; D012333:RNA, Messenger