Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Muromonab-CD3”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed1992

Anti-CD3 monoclonal antibody treatment of patients with CD3-negative tumors: a phase IA/B study.

Anti-CD3 monoclonal antibodies induce the proliferation of human T-cells in vitro and activate specific and nonspecific cytolysis by human T-cell clones and human peripheral blood lymphocytes. In vivo administration of anti-CD3 prevents tumor growth of a UV-induced mouse fibrosarcoma. We conducted a phase I trial to determine the toxicity and immunomodulatory properties of low doses of anti-CD3 in 36 patients with cancer. In 23 patients, anti-CD3 was given i.v. over 3 h at 1, 10, 30, and 100 mcg/patient. Five other patients received anti-CD3 at 30 mcg by i.v. bolus. Patients were treated every 3 days for a total of four doses. An additional eight patients received anti-CD3 daily for 14 days at 3 mcg by i.v. bolus, 3-h infusion, or 24-h infusion. Dose-limiting toxicity was headache. Headache was often accompanied by signs and symptoms of meningeal irritation leading to performance of a lumbar puncture in nine patients. The opening pressure was usually elevated, and six patients had a cerebrospinal fluid lymphocytosis with an elevated protein. Increased levels of interleukin 6 were identified in the cerebrospinal fluid. The maximum tolerated dose by 3-h infusion was 30 mcg. There were no objective tumor responses. There was a dose-related increase in the number of peripheral blood lymphocytes expressing the T-cell activation antigen CD69 (Leu 23), but no changes were seen in CD25 (interleukin 2 receptor) expression, and no changes were observed in the serum levels of the soluble interleukin 2 receptor. Even at these low doses of anti-CD3, 8 of 16 patients tested developed human anti-mouse antibodies.

Adult↗
PubMed1992

Humanized OKT3 antibodies: successful transfer of immune modulating properties and idiotype expression.

Antibodies that possess the Ag-binding regions of OKT3 within the context of a human framework (Hu-OKT3 Ab) offer distinct advantages for optimizing anti-CD3 mAb therapy. First, manipulation of Ab genes to produce humanized Ab that retain Ag-binding activity may circumvent antigenicity problems. Second, Ab gene engineering provides a means for modifying functional properties, including T cell activation and immune suppression. The purpose of this study was to determine the functional properties of Hu-OKT3 Ab and to compare the functional properties and idiotypes of Hu-OKT3 Ab to those of murine OKT3. Three Hu-OKT3 IgG4 Ab, a chimeric OKT3 antibody (cOKT3-1) (grafted sequences comprising all OKT3 VH and VL regions) and two complementarity determining region (CDR)-grafted antibodies, gOKT3-5 and gOKT3-6 (grafted sequences comprising only OKT3 VH and VL CDR and some framework amino acids, were analyzed. Initial studies demonstrated that the cOKT3 and gOKT3-5 Ab bound selectively to T cells and competitively inhibited OKT3-FITC binding with avidities similar to that of murine OKT3. Binding avidity of the gOKT3-6 Ab was markedly less than that of the other two Hu-OKT3 Ab. Serologic analysis suggested that cOKT3 and gOKT3-5 Ab possess idiotypes (combining sites) similar to murine OKT3. T cell activation potency of all three Hu-OKT3 Ab was assessed by proliferation, induction of activation marker expression (IL-2R and Leu 23), and lymphokine production (TNF-alpha and IFN-gamma). The cOKT3 and gOKT3-5 Ab demonstrated T cell activation potencies similar to murine OKT3 as assessed by each parameter. CD3 coating and modulation by these two Ab was effective but somewhat less potent than that observed with OKT3. Finally, cOKT3 and gOKT3-5 Ab both inhibited CTL activity comparably to murine OKT3. In conclusion, these studies indicate that gOKT3-5 and cOKT3 Ab possess immune modulating properties similar to murine OKT3 and thus offer attractive alternatives to murine OKT3 for in vivo therapy.

Amino Acid Sequence↗
PubMed1992

Effect of a single amino acid mutation on the activating and immunosuppressive properties of a "humanized" OKT3 monoclonal antibody.

The binding specificity of the murine OKT3 has been transferred into a human antibody framework to reduce its immunogenicity. This "humanized" anti-CD3 mAb (gOKT3-5) was previously shown to retain, in vitro, all the properties of native OKT3, including T cell activation, which has been correlated, in vivo, with the severe side effects observed in transplant recipients after the first administration of the mAb. T cell activation is thought to be triggered by the cross-linking mediated by the antibodies between T cells and Fc receptor-bearing cells. In this study, we introduced a single amino acid mutation from a leucine to a glutamic acid at position 235 in the Fc receptor binding segment of the gOKT3-5 mAb to produce Glu-235 mAb. This mutation generated a 100-fold decrease in the affinity of the antibody for the Fc receptor on U937 cells, without affecting Ag binding. In parallel, we observed a marked reduction in the T cell activation triggered by the mAb (proliferation, cell surface expression of early activation markers including Leu 23 and IL-2R, and release of TNF-alpha, IFN-gamma, and granulocyte macrophage-CSF). In contrast, the mutated mAb retained suppressive properties similar to the gOKT3-5 mAb, as assessed by significant modulation of the T cell receptor complex and suppression of Ag-specific CTL activity. We conclude that this anti-CD3 mAb bearing a single amino acid mutation in its Fc portion retains important immunosuppressive properties, while exhibiting significantly less T cell activation than OKT3 in vitro. This drug might achieve potent immunosuppression while minimizing acute toxicity in vivo and thus be useful in transplantation as well as in autoimmune diseases.

Amino Acid Sequence↗
PubMed1992

[Construction and expression of murine human chimeric antibody with specificity for CD3 antigen. I. Cloning and sequencing of the VH gene].

By using synthetic oligonucleotide primers specific for VH gene sequences of mouse IgG, PCR amplification of the VH gene from the cDNA of HIT3a hybridoma cells, a murine monoclonal antibody specific to CD3 was successfully performed. The amplified fragment has been cloned into pGEM-7Zf(+)plasmid DNA. Southern analysis shows that the cloned fragment hybridized strongly to both the universal oligonucleotide and DNA probe of the J region of mouse IgG Hc. Analysis of the sequences of recombinant plasmid DNA indicates that the cloned VH gene is 353 bp in size and VDJ4 rearrangement in which the D fragment comes from DSP 2.2, and is grouped into II B subset.

Animals↗