SUMMARYA group of Venezuelan patients with SLE showed an increased proportion of responders to Leu-4, an anti-CD3 Mo Ab of the IgG1 class, compared with ethnically matched non-SLE patients and healthy controls. The rate of proliferative responses or IL-2 production induced by Mo Ab Leu-4, and the helper effect of macrophages from Leu-4 responders on T cells from a third-party donor were comparable in patients and controls. No significant differences in the binding of murine IgG1 molecules by macrophages from SLE patients and controls were observed. The proportion of monocytes/macrophages expressing FcγRI was significantly higher in SLE patients. However, the expression of FcRII, the type capable of supporting Leu-4-mediated responses, and of FcγRIII was comparable in monocytes from SLE patients and controls. Our results suggest that Venezuelan patients with SLE may have a genetic predisposition for the expression of the phenotypic variant of FcγRII capable of binding murine IgG1 molecules.

1991-02-15·Journal of immunology (Baltimore, Md. : 1950)

Stimulation through the TCR/CD3 complex up-regulates the CD2 surface expression on human T lymphocytes.

Article

作者: Places, L ; Alberola-Ila, J ; Yagüe, J ; Gallart, T ; Lozano, F ; de la Calle, O ; Vives, J ; Romero, M

Despite the well known interrelationship between the CD2- and CD3-mediated signal transduction pathways, it is not well established whether the CD2 surface expression can be regulated by triggering of TCR/CD3 complex. In this study we show that the stimulation of human PBMC with the Cris-7 (CD3) mAb, both in soluble and particulate form, results in hyperexpression of the CD2 surface Ag, as assessed by immunofluorescence and semi-quantitative immunoprecipitation assays. Similar effects on CD2 surface expression were obtained when different CD3 mAb (OKT3, RW2-8C8 and Leu-4) were tested. The CD3-mediated CD2 up-regulation was suppressed by cycloheximide and actinomycin D, indicating that it requires de novo protein and RNA synthesis. In agreement with this, increased CD2 RNA levels were observed after 3 h of stimulation, reaching a plateau at 24 h that was maintained for 72 h. The CD2 up-regulation was concomitant to other CD3-induced activation-related events such as induction of surface CD25 and CD71 and high RNA levels for c-myc, IL-2R alpha- and beta-chains, CD71, and IFN-gamma. CD2 up-regulation appeared to be elicited by a protein kinase C-dependent mechanism because it was abrogated by staurosporine, a potent protein kinase C inhibitor. Moreover, IL-2-dependent events may also help in enhancing CD2 hyper-expression because it was only partially inhibitable by cyclosporine, dexamethasone, or Mar-108 (CD25) mAb. In conclusion, our data suggest that CD2 up-regulation can be a relevant event in T cell activation triggered by the physiologic engagement of the TCR/CD3 complex.

1984-07-01·Journal of Experimental Medicine1区 · 医学

Ethnic differences in the lymphocyte proliferative response induced by a murine IgG1 antibody, Leu-4, to the T3 molecule

1区 · 医学

Article

作者: Arabella B. Tilden ; Max D. Cooper ; Toru Abo ; Katsuo Kumagai ; Charles M. Balch ; Gary M. Troup

The mitogenic effects of isotypically diverse antibodies to the T3 molecule were examined in genetically diverse population groups. Whereas the OKT3 antibody (IgG2a) was mitogenic for blood mononuclear cells from all individuals tested, the 38.1 antibody (IgM) was consistently nonmitogenic. In contrast, studies of the mitogenic effects of the Leu-4 antibody (IgG1) revealed striking ethnic differences. More than 80% of Caucasians and Negroes were good Leu-4 responders, whereas most individuals of Asian origin, including Indian, Japanese, and Chinese, were either Leu-4 nonresponders or Leu-4 low responders. However, the majority of American Indians, as well as a significant minority of Chinese, were good responders. Cell separation studies confirmed that monocytes govern the different mitogenic effects of the anti-T3 antibodies. The results reveal interesting ethnic differences in monocyte accessory function probably mediated via the Fc-gamma receptor, in the stimulation of T lymphocytes by an IgG1 antibody against the T3 molecule.

100 项与 LEU-004 相关的药物交易

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