ABSTRACT
An 89-year-old man presented with the chief complaint of a sore throat and a mass in the right side of his neck that tended to increase in size. He displayed the right Horner's sign, and imaging findings showed a 65-mm mass in the right side of the neck, invading the carotid artery. There were no other obvious lesions. The differential diagnosis was carcinoma of an unknown primary or neurogenic tumor. An incisional biopsy was performed, and the pathological diagnosis was lymphomatoid granulomatosis. The patient was started on oral prednisolone, but the disease progressed, and his general condition worsened. Therefore, supportive care was provided. This was a very rare case of a cervical lesion of lymphomatoid granulomatosis.
ABSTRACT
IL-10-producing regulatory T cells (IL-10-producing Tregs) are one of the regulatory T cell subsets characterized by the production of high amounts of IL-10, the lack of FOXP3 expression and the strong immunosuppressive capabilities. IL-10-producing Tregs have been primarily reported as induced populations thus far, in part because identifying naturally occurring IL-10-producing Tregs was difficult due to the lack of definitive surface markers. Lymphocyte-activation gene 3 (LAG3) is a CD4 homologue that we have identified as being expressed on IL-10 producing Tregs. In human PBMC, LAG3 combined with CD49b efficiently identifies IL-10-producing Tregs. However, naturally occurring IL-10-producing Tregs in human secondary lymphoid tissue have not been described. In this report, we identified CD4+CD25-LAG3+ T cells in human tonsil. This T cell subset produced high amounts of IL-10 and expressed low levels of FOXP3. Surface markers and microarray analysis revealed that this is a distinct tonsillar CD4+ T cell subset. CD4+CD25-LAG3+ T cells expressed interleukin 10 (IL10), PR/SET domain 1 (PRDM1), and CD274 at high levels and chemokine receptor 5 (CXCR5) at low levels. CD4+CD25-LAG3+ T cells suppressed antibody production more efficiently than CD4+CD25+ T cells, and CD4+CD25-LAG3+ T cells induced B cell apoptosis. Moreover, analysis of humanized mice revealed that this cell subset suppressed a graft-versus-host disease (GVHD) reaction in vivo. Our study reveals the existence of naturally occurring IL-10-producing Tregs in human secondary lymphoid tissue and their function in immune regulation.
Subject(s)
Interleukin-10/biosynthesis , Lymphoid Tissue/cytology , Palatine Tonsil/cytology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Animals , Antigens, CD/metabolism , Apoptosis/genetics , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Biomarkers , Cytokines/metabolism , Disease Models, Animal , Graft vs Host Disease/genetics , Graft vs Host Disease/immunology , Graft vs Host Disease/metabolism , Humans , Immunophenotyping , Interferon-gamma/metabolism , Mice , Phenotype , Positive Regulatory Domain I-Binding Factor 1/genetics , Positive Regulatory Domain I-Binding Factor 1/metabolismABSTRACT
TGF-ß1 is an important anti-inflammatory cytokine, and several regulatory T cell (Treg) subsets including CD4(+)CD25(+)Foxp3(+) Tregs and Th3 cells have been reported to exert regulatory activity via the production of TGF-ß1. However, it has not yet been elucidated which transcription factor is involved in TGF-ß1 transcription. Early growth response 3 (Egr-3) is a zinc-finger transcription factor that creates and maintains T cell anergy. In this study, we found that Egr-3 induces the expression of TGF-ß1 in both murine and human CD4(+) T cells. Egr-3 overexpression in murine CD4(+) T cells induced the production of TGF-ß1 and enhanced the phosphorylation of STAT3, which is associated with TGF-ß1 transcription. Moreover, Egr-3 conferred Ag-specific regulatory activity on murine CD4(+) T cells. In collagen-induced arthritis and delayed-type hypersensitivity model mice, Egr-3-transduced CD4(+) T cells exhibited significant regulatory activity in vivo. In particular, the suppression of delayed-type hypersensitivity depended on TGF-ß1. In human tonsils, we found that CD4(+)CD25(-)CD45RO(-)lymphocyte activation gene 3 (LAG3)(-) T cells express membrane-bound TGF-ß1 in an EGR3-dependent manner. Gene-expression analysis revealed that CD4(+)CD25(-)CD45RO(-)LAG3(-) T cells are quite different from conventional CD4(+)CD25(+)Foxp3(+) Tregs. Intriguingly, the CD4(+)CD25(-)CD45RO(-)LAG3(-) T cells suppressed graft-versus-host disease in immunodeficient mice transplanted with human PBMCs. Our results suggest that Egr-3 is a transcription factor associated with TGF-ß1 expression and in vivo regulatory activity in both mice and humans.
