Aim: To analyze apoptosis and its degree of thymocytes at early and intermediate phases induced by anti-TCRalphabeta mAb or anti-TCRalphabeta mAb+anti-CD28 mAb stimuli, and to analyze the influence of CD28 costimulator on TCR-induced apoptosis of thymocyte subsets.
Methods: Thymocytes were freshly prepared and were cultured for 20 h in the presence of anti-TCRalphabeta mAb+anti-CD28 mAb or anti-TCRalphabeta mAb along, The cultured cells were stained with fluorescein labelled Annexin V, PI, anti-CD4 mAb and anti-CD8 mAb, then color reagents. The apoptotic cells were analyzed by FACS.
Results: Compared with the spontaneous apoptosis of thymocytes cultured in medium alone, CD28 costimulator markedly enhanced the number of thymocyte apoptosis at early and intermediate phases; under the action of double signaling stimulators, the apoptosis of CD4(+) CD8(+)(DP) thymocytes were substantially increased, and the expression of CD28 were also upregulated on these apoptotic DP cells.
Conclusion: Influence of CD28 costimulator on TCR-induced apoptosis of thymocyte subsets might be related to thymocyte's mature degree. Double signaling may induce apoptosis of DP thymocytes.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Enhanced Costimulation Blockade With αCD154, αCD2, and αCD28 to Promote Heart Allograft Tolerance in Nonhuman Primates.
Transplantation
January 2025
Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
Background: Long-term renal allograft acceptance has been achieved in macaques using a transient mixed hematopoetic chimerism protocol, but similar regimens have proven unsuccessful in heart allograft recipients unless a kidney transplant was performed simultaneously. Here, we test whether a modified protocol based on targeting CD154, CD2, and CD28 is sufficient to prolong heart allograft acceptance or promote the expansion of regulatory T cells.
Methods: Eight macaques underwent heterotopic allo-heart transplantation from major histocompatibility complex-mismatched donors.
CD28 shapes T cell receptor signaling by regulating Lck dynamics and ZAP70 activation.
Front Immunol
January 2025
Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States.
Introduction: T cell activation requires T cell receptor (TCR) engagement by its specific ligand. This interaction initiates a series of proximal events including tyrosine phosphorylation of the CD3 and TCRζ chains, recruitment, and activation of the protein tyrosine kinases Lck and ZAP70, followed by recruitment of adapter and signaling proteins. CD28 co-stimulation is also required to generate a functional immune response.
View Article and Find Full Text PDFenhancement of CD8+ T cell activity using functionalized hydrogel encapsulating tonsil-derived lymphatic endothelial cells.
Theranostics
January 2025
Nano-Bio Regenerative Medical Institute, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea.
This study investigates a method for programming immune cells using a biomaterial-based system, providing an alternative to traditional cell manipulation techniques. It addresses the limitations of engineered adoptive T cell therapies, such as T cell exhaustion, by introducing a gelatin-hyaluronic acid (GH-GMA) hydrogel system. We characterized tonsil mesenchymal stem cells (TMSCs), lymphatic endothelial cells (T-LECs), stimulated T-CD8 T cells (STCs), and GH-GMA biomaterials.
View Article and Find Full Text PDFNI-3201 Is a Bispecific Antibody Mediating PD-L1-Dependent CD28 Co-stimulation on T Cells for Enhanced Tumor Control.
Cancer Immunol Res
January 2025
Light Chain Bioscience - Novimmune SA, Geneva, Switzerland.
Article Synopsis
- Advances in cancer immunotherapy face challenges with patient resistance and relapses, prompting exploration of bispecific antibodies like NI-3201, designed to enhance T-cell activation against tumors.
- NI-3201 works by blocking the PD-L1/PD-1 pathway and providing additional T-cell stimulation through CD28, showing promising in vitro and in vivo results for tumor regression and immune memory.
- Preclinical safety assessments indicate good tolerability, and future studies aim to further investigate NI-3201's potential in improving outcomes for patients with PD-L1+ solid tumors.
Protein Phosphatase 2A Promotes CD8 T Cell Effector Function through the Augmentation of CD28 Costimulation.
Research (Wash D C)
January 2025
Department of Cardiology of The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China.
Protein phosphatase 2A (PP2A) is one of the most abundant serine/threonine phosphatases and plays critical roles in regulating cell fate and function. We previously showed that PP2A regulates the differentiation of CD4 T cells and the development of thymocytes. Nevertheless, its role in CD8 T cells remains elusive.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!