Double Negative (CD3+4−8−) TCRαβ Splenic Cells from Young NOD Mice Provide Long-Lasting Protection against Type 1 Diabetes

Beverly Duncan,Jacqueline Surls,Constantin Bona,Teodor-D Brumeanu,Sofia Casares,Cristina Nazarov–Stoica,Margaret Kehl,Derya Unutmaz

doi:10.1371/journal.pone.0011427

Abstract

BackgroundDouble negative CD3+4−8− TCRαβ splenic cells (DNCD3) can suppress the immune responses to allo and xenografts, infectious agents, tumors, and some autoimmune disorders. However, little is known about their role in autoimmune diabetes, a disease characterized by the reduction of insulin production subsequent to destruction of pancreatic β-cells by a polyclonal population of self-reactive T-cells. Herein, we analyzed the function and phenotype of DNCD3 splenic cells in young NOD mice predisposed to several autoimmune disorders among which, the human-like autoimmune diabetes.Methodology/Principal FindingsDNCD3 splenic cells from young NOD mice (1) provided long-lasting protection against diabetes transfer in NOD/Scid immunodeficient mice, (2) proliferated and differentiated in the spleen and pancreas of NOD/Scid mice and pre-diabetic NOD mice into IL-10-secreting TR-1 like cells in a Th2-like environment, and (3) their anti-diabetogenic phenotype is CD3+(CD4−CD8−)CD28+CD69+CD25low Foxp3− iCTLA-4−TCRαβ+ with a predominant Vβ13 gene usage.Conclusions/SignificanceThese findings delineate a new T regulatory component in autoimmune diabetes apart from that of NKT and CD4+CD25high Foxp3+T-regulatory cells. DNCD3 splenic cells could be potentially manipulated towards the development of autologous cell therapies in autoimmune diabetes.

Highlights

A unique population of T regulatory cells other than Foxp3+ CD4+ and IL-10-secreting TR-1 cells was recently described as ‘‘natural suppressors’’ CD3+4282/TCRab double negative Tcells (DNCD3 cells)
The highest number of DNCD3 thymocytes in newborn NOD mice was detected 7 days after birth in males, but not female littermates. The spleen of both male and female NOD mice showed a gradual increase in the number of DNCD3 cells with a peak at day 14 after birth (10–22% of the entire CD3+ cell compartment) (Figure 1C), which was followed by a decline up to 1–3% of the entire CD3+ cell population some 28 days after birth
This was consistent with previous data showing a relative low number of DNCD3 peripheral cells in NOD mice older than 5 weeks [36]. These data indicated that regardless the gender, the number of DNCD3 splenic cells in NOD mice was relatively high during the postnatal period, and sharply declined in the adulthood

Summary

Introduction

A unique population of T regulatory cells other than Foxp3+ CD4+ and IL-10-secreting TR-1 cells was recently described as ‘‘natural suppressors’’ CD3+4282/TCRab double negative Tcells (DNCD3 cells). These cells were first described in the spleen of adult mice [1], and human peripheral blood [2]. The TCRab repertoire of DNCD3 splenic cells in autoimmune diseases has not been investigated. Double negative CD3+4282 TCRab splenic cells (DNCD3) can suppress the immune responses to allo and xenografts, infectious agents, tumors, and some autoimmune disorders. We analyzed the function and phenotype of DNCD3 splenic cells in young NOD mice predisposed to several autoimmune disorders among which, the human-like autoimmune diabetes

Methods

Results

Conclusion