Large dots in the red pulp are artifactual staining of cells expressing endogenous HRP
Large dots in the red pulp are artifactual staining of cells expressing endogenous HRP. is usually shown. BL/6 na?ve mice served as control. Size bar represents 100m.(TIF) pone.0024772.s001.tif (4.4M) GUID:?701489AE-92D9-482E-AA3F-77C9BEC57A64 Physique S2: Computer virus control in mice deficient in T cell effector mechanisms. 2107 CD8+ T cells from na?ve BL/6 mice were adoptively transferred to IFN-/-, TNF-/-, perforin-/- and FasLdeficient mice before contamination with 200 pfu LCMV. Seventeen days after infection, computer virus titer was measured by plaque forming assay of the peripheral blood from all mice. Each sign represents one mouse. As an assay control LCM computer virus with a titer of 3107pfu/ml was taken.(TIF) pone.0024772.s002.tif (330K) GUID:?F9E97E75-47A1-4C24-948F-53A3F6D403D8 Figure S3: IFN and TNF production in mice deficient in T cell effector mechanisms. 2107 CD8+ T cells from na?ve BL/6 mice were adoptively transferred to IFN-/-, TNF-/-, perforin-/- and FasLdeficient mice before contamination with 200 pfu LCMV. Seventeen days after infection, CD4+ T lymphocytes from your spleen were restimulated for 5h with p13 and analyzed for intracellular IFN and TNF production by circulation cytometry. Numbers show percentage (mean, n?=?3) of CD4+ T cells producing IFN and TNF.(TIF) pone.0024772.s003.tif (2.2M) GUID:?A0834CEC-71C5-4EE3-80E8-77A37A16F6FE Abstract Immune responses have the important function of host defense and protection against pathogens. However, the immune response also causes inflammation and host tissue injury, termed immunopathology. For example, hepatitis B and C computer virus infection in humans cause immunopathological sequel with destruction of liver cells by the host’s own immune response. Similarly, after contamination with lymphocytic choriomeningitis computer virus (LCMV) in mice, the adaptive immune response causes liver cell damage, choriomeningitis and destruction of lymphoid organ architecture. The immunopathological sequel during LCMV contamination has been attributed to cytotoxic CD8+ T cells. However, we now show that during LCMV contamination CD4+ T cells selectively induced the destruction of splenic marginal zone and caused liver cell damage with elevated serum MHY1485 alanin-transferase (ALT) levels. The destruction of the splenic marginal zone by CD4+ T cells included the reduction of marginal zone B cells, marginal zone macrophages and marginal zone metallophilic macrophages. Functionally, this resulted in an impaired production of neutralizing antibodies against LCMV. Furthermore, CD4+ T cells reduced B cells with an IgMhighIgDlow phenotype (transitional stage 1 and 2, marginal zone B cells), whereas other B cell subtypes such as follicular type 1 and 2 and germinal center/memory B cells were not affected. Adoptive transfer of CD4+ T cells lacking different important effector cytokines and cytolytic pathways such as IFN, TNF, perforin and Fas-FasL conversation did reveal that these cytolytic pathways are redundant in the induction of immunopathological sequel in MHY1485 spleen. In conclusion, our results define an important role of CD4+ T cells in the induction of immunopathology in liver and spleen. This includes the CD4+ T cell MHY1485 mediated destruction of the splenic marginal zone with consecutively impaired protective neutralizing antibody responses. Introduction Immune protection against pathogens must be balanced co-evolutionarily against lethal damage by immune responses. The process of host tissue destruction by the own immune system is usually termed immunopathology. Immunopathological sequel occurs during important infections in humans and mice. For example, after contamination with hepatitis B and C computer virus in men, the T cell response causes liver cell damage. Similarly, the T cell response against lymphocytic choriomeningitis computer virus (LCMV) prospects to destruction of secondary lymphoid organs, hepatic damage and choriomeningitis , . Secondary lymphoid organs are highly organized structures, where B and T cells are localized to specialized zones. In contrast to lymph nodes, the lymphoid compartment of the spleen contains an additional structure called marginal zone, which consists of marginal zone macrophages, marginal zone metallophilic macrophages and marginal zone B cells . Non-hematopoietic stromal cells orchestrate the structure of secondary lymphoid HDAC3 organs by expression of chemokines such as CCL19, CCL21, MHY1485 and CXCL13. The integrity of lymphoid organ architecture provides the basis for an optimal adaptive.