The Role of LFA-1 for the Differentiation and Function of Regulatory T Cells—Lessons Learned from Different Transgenic Mouse Models

Regulatory T cells (Treg) are essential for the maintenance of peripheral tolerance. Treg dysfunction results in diverse inflammatory and autoimmune diseases with life-threatening consequences. β<sub>2</sub>-integrins (CD11a-d/CD18) play important roles in the migration of leukocytes int...

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Bibliographic Details
Main Authors: Tanja Klaus, Alicia Wilson, Michael Fichter, Matthias Bros, Tobias Bopp, Stephan Grabbe
Format: Article
Language:English
Published: MDPI AG 2023-03-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/24/7/6331
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Summary:Regulatory T cells (Treg) are essential for the maintenance of peripheral tolerance. Treg dysfunction results in diverse inflammatory and autoimmune diseases with life-threatening consequences. β<sub>2</sub>-integrins (CD11a-d/CD18) play important roles in the migration of leukocytes into inflamed tissues and cell signaling. Of all β<sub>2</sub>-integrins, T cells, including Treg, only express CD11a/CD18, termed lymphocyte function-associated antigen 1 (LFA-1), on their surface. In humans, loss-of-function mutations in the common subunit CD18 result in leukocyte adhesion deficiency type-1 (LAD-1). Clinical symptoms vary depending on the extent of residual β<sub>2</sub>-integrin function, and patients may experience leukocytosis and recurrent infections. Some patients can develop autoimmune diseases, but the immune processes underlying the paradoxical situation of immune deficiency and autoimmunity have been scarcely investigated. To understand this complex phenotype, different transgenic mouse strains with a constitutive knockout of β<sub>2</sub>-integrins have been established. However, since a constitutive knockout affects all leukocytes and may limit the validity of studies focusing on their cell type-specific role, we established a Treg-specific CD18-floxed mouse strain. This mini-review aims to delineate the role of LFA-1 for the induction, maintenance, and regulatory function of Treg in vitro and in vivo as deduced from observations using the various β<sub>2</sub>-integrin-deficient mouse models.
ISSN:1661-6596
1422-0067