Study of neurotrophic factor receptor tyrosine kinase gene fusion in the precise treatment of wild-type gastrointestinal stromal tumor / 中华胃肠外科杂志

The neurotrophin receptor kinase (NTRK) gene encodes neurotrophic factor receptor tyrosine kinase (NTRK), which plays an important role in the development and function of the nervous system. NTRK gene fusion mutation results in the production of chimeric NTRK proteins, which have carcinogenic potential through constitutive activation or overexpression. NTRK gene fusion mutation can lead to a special type of wild type gastrointestinal stromal tumor (GIST), whose clinical manifestations and treatment are completely different from other types of GIST. This fusion mutation can be detected clinically by a variety of methods, including tumor DNA and RNA sequencing and immunohistochemical staining. In patients with NTRK fusion positive tumors, NTRK inhibitors such as larotrectinib and entrectinib have shown good antitumor efficacy, with clinical response rates as high as 75%. Therefore, there is a need to improve the recognition and detection of fuch patients and to improve their prognosis by individualized and precise treatment with TRK inhibitors.

In vivo ligation of glucocorticoid-induced TNF receptor enhances the T-cell immunity to herpes simplex virus type 1

GITR (glucocorticoid-induced TNF receptor) is a recently identified member of the TNF receptor superfamily. The receptor is preferentially expressed on CD4+CD25+ regulatory T cells and GITR signals break the suppressive activity of the subset. In this study, we wanted to reveal the in vivo function of GITR in herpes simplex virus type 1 (HSV-1) infection. A single injection of anti-GITR mAb (DTA-1) immediately after viral infection significantly increased the number of CD4+ and CD8+ T cells expressing CD25, an activation surface marker, and secreting IFN-gamma. We confirmed these in vivo observations by showing ex vivo that re-stimulation of CD4+ or CD8+ T cells with a CD4+ or CD8+ T-cell-specific HSV-1 peptide, respectively, induced a significant elevation in cell proliferation and in IFN-gamma secretion. Our results indicate that GITR signals play a critical role in the T-cell immunity to HSV-1.

Constitutive expression of 4-1BB on T cells enhances CD4+ T cell responses

4-1BB, a transmembrane molecule, member of the tumor necrosis factor receptor superfamily, is an important costimulatory molecule in the immune response, plays a key role in the clonal expansion and survival of CD8(+)T cells. In this study, we investigated 4-1BB regulation of CD4(+)T cell responses using 4-1BB transgenic (TG) mice that constitutively expressed 4-1BB on mature T cells. We first showed that CD4(+)T cells of 4-1BB TG mice had more sustained proliferative capacity in response to TCR/4-1BB stimulation in vitro compared to WT mice. Secondly, 4-1BB TG mice exhibited a more elevated contact hypersensitivity (CHS) response mediated by CD4+ Th1 cells due to more vigorous expansion of and apoptotic inhibition of CD4(+)T cells. Finally, CD4(+)T cells of 4-1BB TG mice had a heightened capacity for T cell priming. Overall, our results demonstrate the involvement of 4-1BB in CD4(+)Th1 cell responses by regulating the clonal expansion and survival of CD4(+)T cells as seen in CD8(+)T cells.