CD8+ T-cell responses identify beta-cell autoimmunity in human type 1 diabetes.
Despite the understanding that type 1 diabetes pathogenesis is mediated by T-cells, detection of these rare lymphocytes remains largely elusive. Suitable T-cell assays are highly needed, since they could offer preclinical diagnoses and immune surrogate end points for clinical trials. Although CD4+ T-cell assays have met with limited success, CD8+ T-cells are increasingly recognized as key actors in the diabetes of the NOD mouse. CD8+ T-cells are likely to play a role also in humans and may provide new markers of beta-cell autoimmunity. Taking advantage of a panel of HLA-A2-restricted beta-cell epitopes derived from preproinsulin, GAD, and islet glucose-6-phosphatase catalytic subunit-related protein (IGRP), we have implemented an islet-specific CD8+ T-cell interferon-gamma enzyme-linked immunospot (ISL8Spot) assay. The ISL8Spot assay is capable of detecting and quantifying beta-cell-reactive CD8+ T-cells directly ex vivo, without any preliminary expansion, using either fresh or frozen samples. Positive ISL8Spot responses separate new-onset diabetic and healthy samples with high accuracy (86% sensitivity, 91% specificity), using as few as five immunodominant epitopes. Moreover, sensitivity reaches 100% when the ISL8Spot assay is complemented by antibody determinations. Combination of CD8+ T-cell measurements with immune intervention strategies may open new avenues toward type 1 diabetes prediction and prevention.
Mallone
Roberto
R
INSERM U580, Hôpital Necker, 161 rue de Sèvres, 75743 Paris Cedex 15, France. mallone@necker.fr
Martinuzzi
Emanuela
E
Blancou
Philippe
P
Novelli
Giulia
G
Afonso
Georgia
G
Dolz
Manuel
M
Bruno
Graziella
G
Chaillous
Lucy
L
Chatenoud
Lucienne
L
Bach
Jean-Marie
JM
van Endert
Peter
P
D000293:Adolescent; D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018984:Epitopes, T-Lymphocyte / Q000378:metabolism; D005260:Female; D015789:HLA-A2 Antigen / Q000378:metabolism; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen