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αβ TCR VS γδ TCR
Online InquiryT cells are an essential component of the adaptive immune system, comprising various subsets differentiated by their TCRs. Among these, αβ TCR and γδ TCR are the two major TCR types that serve distinctive functions in immune surveillance and defense.
Here, Creative Biolabs shares some information about their unique properties, functions, and contributions to the immune system. By understanding the differences and similarities between these two TCR types, it may reveal the diversity and complexity of the immune response, paving the way for advances in immunotherapy and disease treatment.
Two TCRs that are Similar but Different
T cells recognize antigenic peptides through TCR and initiate an immune response, which is the core molecule of T cell therapy. According to the difference of TCR, T cells are divided into αβ and γδ T cells. Although αβ TCR and γδ TCR are similar, they also have many differences.
| αβ TCR | γδ TCR | |
|---|---|---|
| Structure and Composition | αβ TCRs consist of two chains: α and β chains. Each chain contains a variable region (Vα and Vβ) responsible for antigen recognition and a constant region (Cα and Cβ) responsible for signaling and interaction with the CD3 complex. | The structure of γδ TCRs includes γ and δ chains, each with variable (Vγ and Vδ) and constant (Cγ and Cδ) regions. |
| Antigen Recognition | αβ TCRs primarily recognize peptide antigens presented by MHC molecules, making them pivotal in combating intracellular pathogens, such as viruses and intracellular bacteria. | γδ TCRs exhibit a broader antigen recognition spectrum, allowing them to recognize not only peptide antigens but also non-peptide antigens, such as phospholipids, small molecules, and stress-induced proteins. |
| Tissue Localization and Distribution | αβ TCR-expressing T cells have a more widespread distribution, populating lymphoid organs and circulating in the blood, enabling them to mount systemic immune responses against infections. | γδ TCRs are enriched in specific tissues, particularly in epithelial tissues such as the skin and mucosal linings of the gut and respiratory tract. |
| Immune Response | Upon antigen recognition, αβ T cells can differentiate into effector T cells, such as cytotoxic T cells, helper T cells, and regulatory T cells. | They compensate by rapidly responding to stress signals without the need for prior antigen presentation. These unconventional T cells can directly recognize and eliminate infected or damaged cells. |
Role in Diseases and Immunotherapy
The roles of αβ TCRs and γδ TCRs in various diseases have sparked interest in developing immunotherapeutic approaches.
- For instance, adoptive T cell therapy, which involves infusing patients with T cells engineered to express specific αβ TCRs targeting tumor antigens, has shown promising results in cancer treatment.
- Similarly, harnessing the unique properties of γδ T cells for immunotherapy has gained attention. γδ T cells can be engineered to target tumor cells or infected tissues, providing a potential avenue for immunotherapy against certain cancers and infectious diseases.
While αβ T cells offer a wide array of antigen-specific responses, γδ T cells provide rapid and non-conventional immune defense. Understanding the distinctions and complementary roles of these TCR types unlocks new possibilities for immunotherapy and disease treatment, such as αβ TCR-engineered γδ T cells development.
Reference
- Morath A and Schamel W W. αβ and γδ T cell receptors: Similar but different. Journal of leukocyte biology, 2020, 107(6): 1045-1055.
