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Published on: February 28, 2019
The CD28-B7 Family of Co-signaling Molecules
Shigenori Nagai1, Miyuki Azuma2
1Department of Molecular Immunology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. nagai.mim@tmd.ac.jp.
Abstract:
Immune responses are controlled by the optimal balance between protective immunity and immune tolerance. T-cell receptor (TCR) signals are modulated by co-signaling molecules, which are divided into co-stimulatory and co-inhibitory molecules. By expression at the appropriate time and location, co-signaling molecules positively and negatively control T-cell differentiation and function. For example, ligation of the CD28 on T cells provides a critical secondary signal along with TCR ligation for naive T-cell activation. In contrast, co-inhibitory signaling by the CD28-B7 family is important to regulate immune homeostasis and host defense, as these signals limit the strength and duration of immune responses to prevent autoimmunity. At the same time, microorganisms or tumor cells can use these pathways to establish an immunosuppressive environment to inhibit the immune responses against themselves. Understanding these co-inhibitory pathways will support the development of new immunotherapy for the treatment of tumors and autoimmune and infectious diseases. Here, we introduce diverse molecules belonging to the members of the CD28-B7 family.
Insights
Co-inhibitory molecules, like the CD28-B7 family, are crucial for balancing immune responses and preventing autoimmunity. Understanding these pathways aids in developing novel immunotherapies for diseases and cancers.
Area of Science:
- Immunology
- Molecular Biology
Background:
- Immune responses require a balance between protective immunity and tolerance.
- T-cell receptor (TCR) signaling is modulated by co-signaling molecules, including co-stimulatory and co-inhibitory types.
- Co-signaling molecules regulate T-cell differentiation and function based on their expression timing and location.
Purpose of the Study:
- To explore the role of co-inhibitory signaling pathways in immune regulation.
- To introduce the diverse molecules within the CD28-B7 family.
- To highlight the therapeutic potential of understanding these pathways for various diseases.
Main Methods:
- Review of existing literature on T-cell co-signaling.
- Analysis of the CD28-B7 family members and their functions.
- Discussion of the implications for immunotherapy development.
Main Results:
- CD28 ligation provides a key co-stimulatory signal for naive T-cell activation.
- CD28-B7 family co-inhibitory signals are vital for immune homeostasis and preventing autoimmunity.
- Tumor cells and microorganisms can exploit these pathways to create immunosuppressive environments.
Conclusions:
- Understanding CD28-B7 co-inhibitory pathways is essential for developing new immunotherapies.
- These pathways are critical targets for treating tumors, autoimmune diseases, and infectious diseases.
- Further research into diverse CD28-B7 family members can unlock novel therapeutic strategies.
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