Responses against islet antigens in NOD mice are prevented by tolerance to proinsulin but not IGRP
Balasubramanian Krishnamurthy, … , Helen E. Thomas, Thomas W.H. Kay
Balasubramanian Krishnamurthy, … , Helen E. Thomas, Thomas W.H. Kay
Published December 1, 2006
Citation Information: J Clin Invest. 2006;116(12):3258-3265. https://doi.org/10.1172/JCI29602.
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Research Article Metabolism

Responses against islet antigens in NOD mice are prevented by tolerance to proinsulin but not IGRP

Abstract

Type 1 diabetes (T1D) is characterized by immune responses against several autoantigens expressed in pancreatic β cells. T cells specific for proinsulin and islet-specific glucose-6-phosphatase catalytic subunit–related protein (IGRP) can induce T1D in NOD mice. However, whether immune responses to multiple autoantigens are caused by spreading from one to another or whether they develop independently of each other is unknown. As cytotoxic T cells specific for IGRP were not detected in transgenic NOD mice tolerant to proinsulin, we determined that immune responses against proinsulin are necessary for IGRP-specific T cells to develop. On the other hand, transgenic overexpression of IGRP resulted in loss of intra-islet IGRP-specific T cells but did not protect NOD mice from insulitis or T1D, providing direct evidence that the response against IGRP is downstream of the response to proinsulin. Our results suggest that pathogenic proinsulin-specific immunity in NOD mice subsequently spreads to other antigens such as IGRP.

Authors

Balasubramanian Krishnamurthy, Nadine L. Dudek, Mark D. McKenzie, Anthony W. Purcell, Andrew G. Brooks, Shane Gellert, Peter G. Colman, Leonard C. Harrison, Andrew M. Lew, Helen E. Thomas, Thomas W.H. Kay

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Figure 2

T cell responses in NOD and NOD-PI mice after immunization with IGRP206–214 peptide.

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T cell responses in NOD and NOD-PI mice after immunization with IGRP206–...
NOD and NOD-PI mice were primed with 25 μg of IGRP206–214 peptide in CFA (n = 4) or with CFA alone (n = 2). After 1 week, splenocytes were collected and cultured with 106 1500-cGy-irradiated IGRP206–214 loaded NOD splenocytes in complete RPMI supplemented with 10 U/ml rhIL-2 for 6 days. A sample of cultured cells was stained with IGRP206–214 tetramer and analyzed by flow cytometry and the remainder used as effectors in a cytotoxicity assay. (A) IGRP206–214 tetramer–positive CD8+ T cells from spleens of NOD and NOD-PI mice immunized with IGRP206–214 peptide in CFA or with CFA alone. (B) IGRP206–214-specific CD8+ T cells from spleens of NOD-PI mice following priming with IGRP206–214 peptide in CFA were cytotoxic, as assessed by a standard 4-hour 51Cr release assay.