Tumoricidal efficacy coincides with CD11c up-regulation in antigen-specific CD8+ T cells during vaccine immunotherapy

Background: Dendritic cells (DCs) mount tumor-associated antigens (TAAs), and the double-stranded RNA adjuvant Poly(I:C) stimulates Toll-like receptor 3 (TLR3) signal in DC, which in turn induces type I interferon (IFN) and interleukin-12 (IL-12), then cross-primes cytotoxic T lymphocytes (CTLs). Proliferation of CTLs correlates with tumor regression. How these potent cells expand with high quality is crucial to the outcome of CTL therapy. However, good markers reflecting the efficacy of DC-target immunotherapy have not been addressed. Methods: Using an EG7 (ovalbumin, OVA-positive) tumor-implant mouse model, we examined what is a good marker for active CTL induction in treatment with Poly(I:C)/OVA. Results: Simultaneous administration of Poly(I:C) and antigen (Ag) OVA significantly increased a minor population of CD8+ T cells, that express CD11c in lymphoid and tumor sites. The numbers of the CD11c+ CD8+ T cells correlated with those of induced Ag-specific CD8+ T cells and tumor regression. The CD11c+ CD8+ T cell moiety was characterized by its high killing activity and IFN-γ-producing ability, which represent an active phenotype of the effector CTLs. Not only a TLR3-specific (TICAM-1-dependent) signal but also TLR2 (MyD88) signal in DC triggered the expansion of CD11c+ CD8+ T cells in tumor-bearing mice. Notably, human CD11c+ CD8+ T cells also proliferated in peripheral blood mononuclear cells (PBMC) stimulated with cytomegalovirus (CMV) Ag. Conclusions: CD11c expression in CD8+ T cells reflects anti-tumor CTL activity and would be a marker for immunotherapeutic efficacy in mouse models and probably cancer patients as well

IL-1 Signaling Is Critically Required in Stromal Cells in Kawasaki Disease Vasculitis Mouse Model

ObjectiveKawasaki disease (KD) is the most common cause of acute vasculitis and acquired cardiac disease among US children. We have previously shown that both TLR2/MyD88 and interleukin (IL)-1β signaling are required for the Lactobacillus casei cell wall extract-induced KD vasculitis mouse model. The objectives of this study were to investigate the cellular origins of IL-1 production, the role of CD11c(+) dendritic cells and macrophages, and the relative contribution of hematopoietic and stromal cells for IL-1 responsive cells, as well the MyD88 signaling, in Lactobacillus casei cell wall extract-induced KD mouse model of vasculitis.Approach and resultsUsing mouse knockout models and antibody depletion, we found that both IL-1α and IL-1β were required for Lactobacillus casei cell wall extract-induced KD. Both dendritic cells and macrophages were necessary, and we found that MyD88 signaling was required in both hematopoietic and stromal cells. However, IL-1 response and signaling were critically required in nonendothelial stromal cells, but not in hematopoietic cells.ConclusionsOur results suggest that IL-1α and IL-1β, as well as CD11c(+) dendritic cells and macrophages, are essential for the development of KD vasculitis and coronary arteritis in this mouse model. Bone marrow chimera experiments suggest that MyD88 signaling is important in both hematopoietic and stromal cells, whereas IL-1 signaling and response are required only in stromal cells, but not in endothelial cells. Determining the role of IL-1α and IL-1β and of specific cell types in the KD vasculitis mouse model may have important implications for the design of more targeted therapies and understanding of the molecular mechanisms of KD immunopathologies

Reduction of soluble complement receptor 2/CD21 in systemic lupus erythomatosus and Sjogren's syndrome but not juvenile arthritis

A soluble form of the complement receptor CD21 (sCD21) is shed from the lymphocyte surface. The amount of sCD21 in serum may modulate immunity as sCD21 levels are correlated with several clinical conditions. We report here the serum levels of sCD21 in juvenile arthritis (JA), systemic lupus erythematosus (SLE) and Sjogren's syndrome (SS). Using enzyme-linked immunosorbent assay, we determined sCD21 levels in SLE, SS and JA patients. Mann-Whitney test for nonparametric two-tail P value was performed to obtain statistical significance. Cytometrical analysis of synovial fluid leucocytes of JA patients was done on a FACSsort. While sCD21 levels in SLE and SS are reduced to levels previously found in rheumatoid arthritis (RA), JA sCD21 levels were normal. sCD21 levels did not correlate with clinical parameters and immunophenotype of synovial cells. CD4 T cells in the synovium were almost all of the CD45RO memory type and 13 of 40 patients displayed synovial expansion of gammadeltaT cells. CD21 shedding in JA differs from RA/SS/SLE. JA sCD21 levels in synovial fluid are always lower compared to blood levels of the same patients. Analysis of JA synovial T cells indicates a T-cell driven response