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.
Gastrointestinal Stromal Tumors/genetics* ; Gene Fusion ; Humans ; Neoplasms ; Nerve Growth Factors ; Protein Kinase Inhibitors ; Receptor, trkA/genetics* ; Receptors, Nerve Growth Factor/genetics*

Animals ; Food Hypersensitivity ; genetics ; immunology ; metabolism ; Forkhead Transcription Factors ; genetics ; metabolism ; Glucocorticoid-Induced TNFR-Related Protein ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; genetics ; Receptors, Nerve Growth Factor ; genetics ; metabolism ; Receptors, Tumor Necrosis Factor ; genetics ; metabolism ; T-Lymphocytes, Regulatory ; metabolism

OBJECTIVETo investigate the gene expression of 4-1BB in peripheral blood mononuclear cells (PBMCs) and the possible significance of the 4-1BB pathway after clinical orthotopic liver transplantation (OLT).

METHODS4-1BB mRNA levels in PBMCs from 22 OLT patients were analyzed by RT-PCR. 4-1BB protein expressed on the surface of CD(4)(+) and CD(8)(+) T cells were detected by flow cytometry, and visualized with direct immunofluorescence and confocal fluorescence microscopy. Patients with primary liver cancer (PLC) and healthy volunteers served as controls. Six cases of recently performed liver transplantation were also observed in this study.

RESULTS4-1BB mRNA was detected in PBMCs from both liver transplant patients with long-term graft acceptance (22 cases) and from transplant patients on day 1 to day 3 post-transplantation (6 cases), but was not found in PBMCs from transplant patients on day 7 to day 30 post-transplantation (6 cases). 4-1BB mRNA was also not found in samples from 8 of the healthy controls and 7 of the PLC patients, though very low expression was detected in the other 4 healthy volunteers and 6 PLC patients. Simultaneously, 4-1BB protein was expressed at nearly undetectable levels on CD(4)(+) and CD(8)(+) T cells from healthy controls, PLC patients, as well as OLT patients within the first month post-transplantation (6 cases). However, 4-1BB expression was found on the surface of CD(4)(+) and CD(8)(+) T cells from liver transplant patients with long-term graft acceptance. Direct immunofluorescent staining and confocal fluorescence microscopy clearly revealed evidence of 4-1BB protein on cell membranes of CD(4)(+) and CD(8)(+) T cells from liver transplant patients with long-term graft acceptance. Simultaneously, a significantly higher percentage of CD(3)(+) CD(25)(+) T cells were found in liver transplant patients with long-term graft acceptance group as compared with the healthy control group (P < 0.05). The expression of 4-1BB protein on T cells did not correlate with the survival time of OLT patients postoperation.

CONCLUSIONSThis study demonstrates that although patients remain in stable condition after liver transplantation under the treatment of immunosuppressants, activated T cells are present to some extent and 4-1BB protein may be involved in this process. Effector T-cells can exert permanent immunoresponses against grafts under these circumstances. Therefore, we conclude that a new immune response balance is established under the combination of both treatment with immunosuppressants and natural immune responses against alloantigens. Manipulation of the 4-1BB/4-1BBL pathway may provide a therapeutic technique for prolonging graft survival.

Adult ; Antigens, CD ; Female ; Gene Expression ; Humans ; Leukocytes, Mononuclear ; chemistry ; Liver Transplantation ; Male ; Middle Aged ; Receptors, Nerve Growth Factor ; genetics ; physiology ; Receptors, Tumor Necrosis Factor ; genetics ; physiology ; Tumor Necrosis Factor Receptor Superfamily, Member 9

Humans ; Nerve Tissue Proteins ; Epithelial-Mesenchymal Transition/genetics* ; Constriction, Pathologic ; Receptors, Immunologic ; Epithelial Cells/metabolism* ; Smad3 Protein/metabolism* ; Transforming Growth Factor beta1/metabolism*

BACKGROUNDBy unbiased stereological methods, we have observed preferential dorsal root ganglion (DRG) B-cell loss in rodents after nerve injury, and caspase-3 activation and cell loss were related to the present of p75 receptor (p75(NTR)). We hypothesized that DRG B-cells express higher levels of pro-apoptotic proteins as compared to A-cells and the expressions of pro-apoptotic proteins can be reduced by depletion of p75(NTR). This study aimed to identify the p75(NTR) involved apoptotic pathway in DRG neurons after nerve injury.

METHODSThe p75(NTR) knockout mice (p75-/-) and wildtype Balb/C mice (p75+/+) were used in this study. The expressions of pro-apoptotic proteins, c-Jun-N-terminal kinase (JNK), c-jun and p38 in DRG were evaluated with immunohistochemistry 2 and 7 days following unilateral sciatic nerve transection. In addition, extra-cellular related kinase (ERK), a transducer of survival signals, was also tested with immunohistochemistry and Western blotting methods in these animal models.

RESULTSPhosphorylated JNK (P-JNK) and phosphorylated p38 (P-p38) were mainly located in small B-cells, whereas phosphorylated c-jun (P-c-jun) was located in both A- and B-cells. Phosphorylated ERK (P-ERK) was located in both B-cells and satellite cells. Axotomy dramatically increased the expressions of P-JNK and P-c-jun (paired t-test), with no influence on the expressions of P-p38 and P-ERK. Furthermore, the increase of P-JNK in p75+/+ mice 2 days after nerve axotomy was approximately 2.2-folds of that in p75-/- mice (P = 0.001, unpaired t-test).

CONCLUSIONp75(NTR)-dependent JNK-caspase-3 pathway is involved in DRG B-cell loss after nerve injury and JNK is not the unique upstream of c-jun activation.

Animals ; Apoptosis ; genetics ; physiology ; Axotomy ; adverse effects ; Blotting, Western ; Ganglia, Spinal ; cytology ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Knockout ; Neurons ; cytology ; metabolism ; Receptors, Nerve Growth Factor ; genetics ; metabolism ; Sciatic Nerve ; surgery

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.
Animals ; Antibodies/immunology ; Antigens, CD ; Antigens, CD137 ; CD4-Positive T-Lymphocytes/cytology/*immunology/*metabolism ; Cell Division ; Cell Lineage ; Dermatitis, Contact/genetics/immunology ; Flow Cytometry ; Gene Expression ; Mice ; Mice, Transgenic ; Receptors, Nerve Growth Factor/*genetics/*metabolism ; Receptors, Tumor Necrosis Factor/*genetics/*metabolism

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.
Animals ; Antibodies, Monoclonal/pharmacology ; CD4-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cell Proliferation ; Female ; Glucocorticoids/*pharmacology ; Herpes Simplex/*immunology ; Herpesvirus 1, Human/pathogenicity ; *Immunity, Cellular ; Interferon Type II/secretion ; *Lymphocyte Activation ; Mice ; Mice, Inbred BALB C ; Peptide Fragments/metabolism ; Receptors, Interleukin-2/metabolism ; Receptors, Nerve Growth Factor/genetics/immunology/*metabolism ; Receptors, Tumor Necrosis Factor/genetics/immunology/*metabolism ; Research Support, Non-U.S. Gov't ; T-Lymphocytes/*immunology/metabolism/virology

OBJECTIVETo isolate, culture and identify glioma stem cells from human malignant glioma cell line U87, and investigate the changes of pro-angiogenic factors production by glioma stem cells followed by activation of CXCR4 and observe their tumorigenesis as well as the expression of vascular endothelial growth factor when implanted into nude mice.

METHODSThe ratio of CD133 positive cells was detected by flow cytometry. Magnetic separation of CD133 positive cells was carried out on the magnetic cell sorting system (MACS). Expression of nestin, glial fibrillary acidic protein (GFAP) and CXCR4 on tumorspheres was detected by indirect immunofluorescence under confocal laser scanning microscopy. The functional activation of CXCR4 was assessed by calcium mobilization experiments. ELISA was used to detect the production of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) in conditioned medium. Glioma stem cells were implanted into nude mice to assess their tumorigenesis ability and the expression of VEGF.

RESULTSThe ratio of CD133 positive cells with stem cell property was 0.5% in U87 cells. Activation of CXCR4 on glioma stem cells induced calcium mobilization and increased VEGF and IL-8 protein secretion. CD133 positive cells secreted more VEGF and IL-8 than their negative counterparts in vitro. Tumors derived from CD133 positive cells grew more rapidly and expressed elevated level of VEGF than their negative counterparts.

CONCLUSIONSThere are a small fraction of glioma stem cells in human glioblastoma cell line U87. Expressing functional CXCR4 and secreting more pro-angiogenic factors may be involved in tumor angiogenesis mediated by glioma stem cells.

AC133 Antigen ; Animals ; Antigens, CD ; analysis ; Brain Neoplasms ; blood supply ; metabolism ; pathology ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; Glial Fibrillary Acidic Protein ; metabolism ; Glioblastoma ; blood supply ; metabolism ; pathology ; Glycoproteins ; analysis ; Humans ; Interleukin-8 ; metabolism ; Intermediate Filament Proteins ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Neoplastic Stem Cells ; metabolism ; transplantation ; Neovascularization, Pathologic ; Nerve Tissue Proteins ; metabolism ; Nestin ; Peptides ; analysis ; Receptors, CXCR4 ; genetics ; metabolism ; physiology ; Vascular Endothelial Growth Factor A ; metabolism