GMP-TL778 Anti-Human CD137 mAb Induces T cell proliferation and cytokine secretion

4-1BB, also known as CD137, is an inducible cell surface receptor and one member of tumor necrosis factor receptor (tumor  necrosis  factor  receptor,  TNFR)  superfamily.  CD137  is  encoded  by  the  tumor  necrosis  factor  receptor superfamily  member  9  (TNFRSF9)  gene  and  widely  expressed  on  the  surface  of activated  T  cells  and  NK  cells.  Its ligand, CD137L, also a TNFSF member, is an inducible costimulatory receptor expressed by activated CD4 + and CD8 + T cells, NKT, NK cells, DC, macrophages, eosinophils, neutrophils and mast cells, especially on CD8 + T cells. CD137 / CD137L mediate immune responses by transmitting activation, proliferation, or apoptotic signals between immune cells.   The activation of CD137 can stimulate NK cell and T cell proliferation and generate anti-tumor activity, which induces durable memory responses. 4-1BB mAb can activate 4-1BB to recruit TNFR related factors TRAF1 and TRAF2. Then, TRAF1 and TRAF2 form a heterotrimer, which strengthens signal transduction through c-Jun N terminal kinase (JNK) or extracellular signal-regulated kinase (ERK) pathway. This heterotrimer can stimulate the proliferation of T cells and antigen-presenting  cells,  improve  anti-tumor  immune  response  of  the  body  and  secrete  cytokines  through  the transcription of NF-κB.