Autoimmunity to Thy-1

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Autoimmunity involves the immune system attacking self-antigens.
• Thy-1 (Thymocyte antigen 1) is a cell surface glycoprotein found on thymocytes and neurons.
• Understanding the genetic basis of self-antigen recognition is crucial for autoimmune disease research.

Purpose of the Study:

• To describe conditions for inducing autoimmunity to Thy-1.
• To characterize autoantibodies against Thy-1.
• To investigate the genetic control of Thy-1 epitope expression.

Main Methods:

• Induction of autoimmunity in mice.
• Characterization of monoclonal autoantibodies using CBA and AKR strains.
• Epitope mapping and analysis of species and tissue distribution.
• Transfection studies using cloned Thy-1b gene.
• Analysis of inheritance patterns of epitope expression differences.

Main Results:

• Successful induction of autoimmunity to Thy-1.
• Identification of a complex genetic control at the Thy-1 locus with evidence for intragenic control.
• Autoantibody-recognized epitopes showed distinct species and tissue distribution compared to alloantigenic determinants.
• Transfection studies confirmed the specificity of autoantibodies.
• Quantitative and qualitative differences in epitope expression between Thy-1a and Thy-1b alleles were inherited as single Mendelian traits.

Conclusions:

• The Thy-1 locus exhibits a previously unrecognized complexity in epitope expression.
• Evidence suggests intragenic control over Thy-1 epitope recognition.
• Differences in epitope expression between alleles are likely regulated at the translational level, as suggested by Mendelian inheritance without recombination.