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Updated: Jun 26, 2026

Preparation of Single-Cell Suspension of Mouse Thymic Epithelial Cells and Staining of Intracellular Molecules for Flow Cytometric Analysis
Published on: July 26, 2024
Multifaceted regulation of thymic tolerance by pattern recognition cascades
Soumyadeep Mukherjee1, Paramita Paul1, Arpita Kar2
1Department of In Vitro Carcinogenesis and Cellular Chemotherapy, Chittaranjan National Cancer Institute, Kolkata, India.
During their development, progenitor T cells have to pass through a series of tolerogenic filters inside the thymus, which ensure the survival and developmental advancement of only those thymocytes which fruitfully recognize the host's own MHCs conjugated with non-self antigenic peptides. A set of microbial and host-derived biomolecules, called 'patterns', dynamically regulates the proficiency of this thymopoietic axis by a combination of thymocyte-extrinsic antigen presentation and thymocyte-intrinsic TCR signalling. Although well-characterized in terms of their impact on peripheral T cell tolerance, there is a lack of clarity regarding the influence of these patterns on the thymic tolerogenic checkpoints. From a clinical angle, this stands as a formidable weak point for the widely used immunosuppressive therapies against autoimmunity, which generically target these pattern recognition cascades. This review explores different aspects of the pattern recognition receptor-mediated regulation of key thymic events from an exclusively tolerogenic perspective, and unravels the mechanistic complexity underlying their impact on thymic tolerance. As the pattern recognition-mediated signalling cascades constitute a significant branch of the inflammatory network, inferences from this review elaborate a frequently overlooked collaboration between inflammation and self-tolerance; highlighting the need for potential therapeutic repurposing against autoimmune diseases.
During their development, progenitor T cells have to pass through a series of tolerogenic filters inside the thymus, which ensure the survival and developmental advancement of only those thymocytes which fruitfully recognize the host's own MHCs conjugated with non-self antigenic peptides. A set of microbial and host-derived biomolecules, called 'patterns', dynamically regulates the proficiency of this thymopoietic axis by a combination of thymocyte-extrinsic antigen presentation and thymocyte-intrinsic TCR signalling. Although well-characterized in terms of their impact on peripheral T cell tolerance, there is a lack of clarity regarding the influence of these patterns on the thymic tolerogenic checkpoints. From a clinical angle, this stands as a formidable weak point for the widely used immunosuppressive therapies against autoimmunity, which generically target these pattern recognition cascades. This review explores different aspects of the pattern recognition receptor-mediated regulation of key thymic events from an exclusively tolerogenic perspective, and unravels the mechanistic complexity underlying their impact on thymic tolerance. As the pattern recognition-mediated signalling cascades constitute a significant branch of the inflammatory network, inferences from this review elaborate a frequently overlooked collaboration between inflammation and self-tolerance; highlighting the need for potential therapeutic repurposing against autoimmune diseases.
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