ABSTRACT
While previous reports have demonstrated the efficacy of regulatory T cell therapy in the prevention of diabetes, systemic immunocompromise and Treg instability remain key safety concerns. Here we examined the influence of induced Treg (iTreg) cell therapy on anti-viral host defense and autoimmune T cell responses during acute viral infection in a murine model of autoimmune diabetes. Protective transfers of iTregs maintained IL-10 expression, expanded in vivo and controlled diabetes, despite losing FoxP3 expression. Adoptive transfer of iTregs affected neither the primary anti-viral CD8 T cell response nor viral clearance, although a significant and sustained suppression of CD4 T cell responses was observed. Following acute viral clearance, iTregs transferred early suppressed both CD4 and CD8 T cell responses, which resulted in the reversion of diabetes. These observations indicate that iTregs suppress local autoimmune processes while preserving the immunocompetent host's ability to combat acute viral infection.
Subject(s)
Diabetes Mellitus, Type 1/immunology , Lymphocytic Choriomeningitis/immunology , Lymphocytic choriomeningitis virus/immunology , T-Lymphocytes, Regulatory/immunology , Acute Disease , Adoptive Transfer , Animals , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cells, Cultured , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/therapy , Flow Cytometry , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/immunology , Forkhead Transcription Factors/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Host-Pathogen Interactions/immunology , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-10/immunology , Interleukin-10/metabolism , Lymphocytic Choriomeningitis/complications , Lymphocytic Choriomeningitis/virology , Lymphocytic choriomeningitis virus/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , T-Lymphocytes, Regulatory/metabolism , T-Lymphocytes, Regulatory/transplantation , Time Factors , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Cytomegalovirus gene expression in highly permissive, cultured fibroblasts occurs in three kinetic classes known as immediate early, early, and late. Infection of these cells results in a predictable transcriptional program leading to high levels of virus production. Infection of other, so-called, nonpermissive cell types results in a transcriptional program that either fails to produce virus particles or production is substantially reduced compared to fibroblasts. We have found that CMV gene expression profiles in tissues from infected hosts differ greatly from those observed in infected tissue culture cells. The number of viral genes expressed in tissues is much more limited, and the number of highly active genes does not correlate with viral DNA load. Additionally, viral gene expression in vivo is tissue selective with no two tissues expressing the exact same viral gene profile. Thus, in vivo CMV gene expression appears to be governed by mechanisms that are still uncharacterized. Cytomegalovirus remains in a persistent phase for the lifetime of the host. During this phase only a limited number of host cells are infected, and it is very difficult to detect CMV gene expression in whole tissues without sub-fractionating infected vs. uninfected cells. Herein, we describe the development of a fluorescence-based laser capture microscopy technique coupled with small sample size microarray analysis to determine the viral gene expression in 50-100 infected cells isolated from frozen RCMV-infected tissue sections.
