Pro- and anti-inflammatory cytokine production by autoimmune T cells against preproinsulin in HLA-DRB1*04, DQ8 Type 1 diabetes.
OBJECTIVE
Preproinsulin is a target T cell autoantigen in human Type 1 diabetes. This study analyses the phenotype and epitope recognition of preproinsulin reactive T cells in subjects with a high genetic risk of diabetes [HLA-DRB1*04, DQ8 with Ab+ (autoantibody-positive) or without islet autoantibodies (control subjects)], and in HLA-matched diabetic patients.


METHODS
A preproinsulin peptide library approach was used to screen for cytokine profiles and epitope specificities in human peripheral blood lymphocytes, and CD4(+)CD45RA(-) and CD4(+)CD45RA(+) T cell subfractions, representing memory and naive and recently primed T cells respectively.


RESULTS
In CD4(+) T cell subsets we identified immunodominant epitopes and cytokine production patterns that differed profoundly between patients, Ab+ subjects and non-diabetic HLA-matched control subjects. In Ab+ subjects, a C-peptide epitope C13-29 and insulin B-chain epitope B11-27 were preferentially recognised, whereas insulin-treated Type 1 diabetic patients reacted to native insulin and B-chain epitope B1-16. In peripheral blood lymphocytes of Ab+ subjects, an increase in T helper (Th) 1 (IFNgamma, IL-2) and Th2 (IL-4) cytokines was detectable, wheras in CD45RA(+) and CD45RA(-) subsets, IL-4 and IL-10 phenotypes dominated, compatible with the contribution of non-CD4 cells to IFNgamma content. In insulin-treated Type 1 diabetic patients, naive and recently primed CD4(+) cells were characterised by increasd IFNgamma, TNFalpha, and IL-5.


CONCLUSIONS
Our data show that T cell reactivity to preproinsulin in CD45RA subsets is Th2-dominant in Ab+ subjects, challenging the Th1 paradigm in Type 1 diabetes. Characteristic immunodominant epitopes and cytokine patterns distinguish diabetic patients and Ab+ subjects from HLA-matched healthy individuals. This could prove useful in monitoring of T-cell immunity in clinical diabetes intervention trials.
Durinovic-Belló
I
I
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany. ivana.durinovic-bello@medizin.uni-ulm.de.
Schlosser
M
M
Institute of Pathophysiology Karlsburg, University of Greifswald, Greifswald, Germany.
Riedl
M
M
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany.
Maisel
N
N
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany.
Rosinger
S
S
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany.
Kalbacher
H
H
Medical Scientific Center, University of Tübingen, Tübingen, Germany.
Deeg
M
M
Section Transplantation Immunology Medical Clinic, University of Tübingen, Tübingen, Germany.
Ziegler
M
M
Institute of Pathophysiology Karlsburg, University of Greifswald, Greifswald, Germany.
Elliott
J
J
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
Roep
B O
BO
Department of Immunohaematology & Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands.
Karges
W
W
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany.
Boehm
B O
BO
Department of Internal Medicine I, Division of Endocrinology, University of Ulm, Robert-Koch Str. 8, 89081, Ulm, Germany.
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood; D015551:Autoimmunity; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D016207:Cytokines / Q000096:biosynthesis; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology*; D006683:HLA-DQ Antigens / Q000097:blood*; D006684:HLA-DR Antigens / Q000097:blood*; D059811:HLA-DRB1 Chains; D006650:Histocompatibility Testing; D006801:Humans; D007328:Insulin; D017493:Leukocyte Common Antigens / Q000276:immunology; D011384:Proinsulin / Q000276:immunology*; D011498:Protein Precursors / Q000276:immunology*; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology*
D001323:Autoantibodies; D016207:Cytokines; D006683:HLA-DQ Antigens; C109756:HLA-DQ8 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007328:Insulin; D011498:Protein Precursors; C013737:preproinsulin; D011384:Proinsulin; D017493:Leukocyte Common Antigens; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1