Costimulation Blockade Disrupts CD4 + T Cell Memory Pathways and Uncouples Their Link to Decline in β-Cell Function in Type 1 Diabetes

J Immunol. 2020 Jun 15;204(12):3129-3138. doi: 10.4049/jimmunol.1901439. Epub 2020 May 13.


We previously reported that costimulation blockade by abatacept limits the decline of β-cell function and the frequency of circulating CD4+ central memory T cells (TCM) (CD45RO+CD62L+) in new-onset type 1 diabetes. In human subjects receiving placebo, we found a significant association between an increase in CD4+ TCM cells and the decline of β-cell function. To extend and refine these findings, we examined changes in human CD4+ and CD8+ naive and memory T cell subsets at greater resolution using polychromatic flow and mass cytometry. In the placebo group, we successfully reproduced the original finding of a significant association between TCM and β-cell function and extended this to other T cell subsets. Furthermore, we show that abatacept treatment significantly alters the frequencies of a majority of CD4+ conventional and regulatory T cell subsets; in general, Ag-naive subsets increase and Ag-experienced subsets decrease, whereas CD8+ T cell subsets are relatively resistant to drug effects, indicating a lesser reliance on CD28-mediated costimulation. Importantly, abatacept uncouples the relationship between changes in T cell subsets and β-cell function that is a component of the natural history of the disease. Although these data suggest immunological markers for predicting change in β-cell function in type 1 diabetes, the finding that abatacept blunts this relationship renders the biomarkers nonpredictive for this type of therapy. In sum, our findings point to a novel mechanism of action for this successful immunotherapy that may guide other disease-modifying approaches for type 1 diabetes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abatacept / pharmacology
  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology*
  • Biomarkers / blood
  • CD28 Antigens / immunology
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / immunology
  • Cells, Cultured
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / immunology*
  • Humans
  • Immunologic Memory / drug effects
  • Immunologic Memory / immunology*
  • Insulin-Secreting Cells / drug effects
  • Insulin-Secreting Cells / immunology
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / immunology


  • Biomarkers
  • CD28 Antigens
  • Abatacept