Dose Of anti-CD3 Research Articles

EBV infection and anti-CD3 treatment for Type 1 diabetes: bad cop, good cop?

EBV infection and anti-CD3 treatment for Type 1 diabetes: bad cop, good cop?

Cytohesin Binder and Regulator Augments T Cell Receptor-induced Nuclear Factor of Activated T Cells·AP-1 Activation through Regulation of the JNK Pathway

Cytohesin binder and regulator (Cybr; also known as CYTIP, CASP, and PSCDBP) is a cytokine-induced gene preferentially expressed in hematopoietic tissues and in T helper 1 cells. Cybr protein associates with members of the cytohesin family, which are known ADP-ribosylation factors-GDP/GTP exchange factors, and its functions appear to regulate lymphocyte adhesion and cell-cell contact. Here we show that Cybr mRNA and protein levels are increased upon T cell receptor engagement. Cybr expression then influences T cell receptor-dependent signaling events, such as nuclear factor of activated T cells and AP-1 transcriptional activity. In addition, expression of Cybr results in increased T cell receptor-mediated activation of the Rho/Rac exchange factor Vav and of the JNK-p38 MAPK signaling pathway. The effects of Cybr on nuclear factor of activated T cells and AP-1 are dependent on MAPK activation, and enhanced activation of this cascade results in cooperation between the two transcription factors in the regulation of gene expression. These findings provide the first evidence that the adaptor protein Cybr not only regulates lymphocyte adhesion and cell-cell interaction but also contributes to the regulation of the signaling cascade and of the genetic program downstream of the T cell receptor.

Effects of Ganoderma lucidum polysaccharides on proliferation and cytotoxicity of cytokine-induced killer cells

To study the effects (and the mechanisms thereof) of Ganoderma lucidum polysaccharides (Gl-PS) on the proliferation and the anti-tumor activity of cytokine-induced killer (CIK) cells, and to make use of CIK cells as a means to investigate the interactions between Gl-PS and cytokines. CIK cells were prepared by using the standard protocol as a positive control. Experimental groups also underwent the standard protocol, except that Gl-PS (400 mg/L or 100 mg/L) was added and the dose of anti-CD3 and interleukin-2 they received was reduced by 50% and 75%, respectively. For negative controls, Gl-PS in the experimental protocol was replaced with soluble starch or methylcellulose (400 mg/L or 100 mg/L). CIK cell proliferation, cytotoxicity, and phenotype were determined by using the Trypan blue exclusion method, MTT assay, and flow cytometry. By synergizing cytokines, Gl-PS (400 mg/L or 100 mg/L) could decrease the amount of cytokine in lymphokine activated killer (LAK) cells and CIK cells culture, but had no significant effect on the proliferation, cytotoxicity, or phenotype of LAK cells, or CIK cells induced by cytokines at higher doses alone, in which CIK cells expanded about 80-fold and the main effectors, CD3+NK1.1+ cells, expanded by more than 15%. The cytotoxicity of CIK cells in experimental groups was 79.3%+/-4.7%, 76.9%+/-6.8% versus the positive control 80.7%+/-6.8% against P815 (P>0.05) and 88.9%+/-5.5%, 84.7%+/-7.9% versus the positive control 89.8%+/-4.5% against YAC-1 (P>0.05). The activity of Gl-PS could mostly be blocked by anti-CR3. Gl-PS was shown to be a promising biological response modifier and immune potentiator. The effect of Gl-PS on CIK cells is possibly mediated primarily through complement receptor type 3.

Specific Tolerance Induction and Organ Transplantation

Induction of tolerance to histocompatibility antigens of an organ donor would eliminate the need for long-term administration of nonspecific immunosuppressive drugs associated with an increased risk of infection and malignancies. Recently, we established a murine model in which recipient mice were treated with a single dose of anti-CD3, anti-CD4, low dose of total body irradiation (TBI) and allogeneic bone marrow cells. Our results clearly demonstrate that stable multilineage mixed chimerism, immunocompetence and permanent donor-specific skin graft tolerance across full major histocompatibility (MHC) barriers can be successfully achieved in this way. The observations that the preparative regimen and skin transplantation can be performed on the same day, and that a significant reduction in irradiation dose is sufficient in haploidentical donor-recipient combinations (MHC-sharing effect), bring our protocol closer to clinical use.

Immobilized anti-CD3 antibody activates T cell clones to induce the production of interstitial collagenase, but not tissue inhibitor of metalloproteinases, in monocytic THP-1 cells and dermal fibroblasts.

In this study we have investigated whether direct cell to cell contact between activated paraformaldehyde-fixed T cell clones obtained from synovial tissue of patients with osteoarthritis (OA) or rheumatoid arthritis and target monocytic cells or dermal fibroblasts influenced the balance between interstitial collagenase and its specific inhibitor tissue inhibitor of metalloproteinases (TIMP) produced by the latter cell types. PHA/PMA-activated fixed T cell clones or their membranes strongly induced the production of collagenase both in monocytic THP-1 cells and in dermal fibroblasts. In contrast, only low levels of TIMP were induced in THP-1 cells and no change of TIMP expression was observed in fibroblasts as a result of stimulation with PHA/PMA-activated T cells or T cell membranes. Anti-CD3-activated T cell clones stimulated the production of collagenase both in THP-1 cells and fibroblasts, whereas TIMP levels were not influenced. Collagenase production in THP-1 cells induced by anti-CD3-activated T cell clones was 1) dependent on the dose of anti-CD3 used to stimulate the T cells, 2) initiated only when CD3 was cross-linked, and 3) inhibited when cyclosporin A was included during T cell activation. Our data collectively indicate that activated T cells in contact with monocytic cells or fibroblasts may alter the balance between interstitial collagenase and its specific inhibitor TIMP. This selective induction of a mediator profile representative of matrix breakdown as a result of target cell interaction with activated T cells may be an important factor in the local process of tissue destruction that characterizes osteoarthritis and rheumatoid arthritis.