Muromonab-CD3 (brand name Orthoclone OKT3, marketed by Janssen-Cilag) is an immunosuppressant medication given to reduce acute rejection in people with organ transplants. [1][2] It is a monoclonal antibody targeted at the CD3 receptor, [3] a membrane protein on the surface of T cells.

Comodulation of the antigen receptor with CD3 explains the immunoblocking action of OKT3 in vivo. Experience with a second or third treatment with OKT3 indicates that OKT3 is ineffective clinically if the CD3 target molecule is not modulated.

The OKT3 monoclonal antibody reacts with an epitope on the epsilon-subunit within the human CD3 complex. Clone OKT3 can block the binding of clones SK7 and UCHT1. 4 The OKT3 antibody is able to induce T cell activation.

Muromonab-CD3 (also known as OKT3) is a murine IgG2a antibody directed at the ɛ-chain of CD3 that was first used in the setting of renal transplant induction therapy in the 1980s: it was shown to be effective in the treatment of acute allograft rejection.

Feb 1, 2003 · CD3-specific monoclonal antibodies are highly species specific — OKT3 recognizes chimpanzee cells but, in contrast to antibodies specific for human CD4 or CD8, it does not cross-react with...

A decade later, scientists supported by NIH’s National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and others learned that treating mouse models of diabetes with an anti-CD3 antibody delayed disease onset, but OKT3 caused negative side effects in humans. Researchers discovered how OKT3 caused these side effects and ...

Dec 28, 2020 · Muromonab-CD3 is a mouse monoclonal antibody to CD3, often referred to as OKT3, which was withdrawn from use in 2010 but was previously used to treat acute cellular rejection after solid organ transplantation.

The anti-CD3 monoclonal antibody (OKT3) recognizes CD3, a human glycoprotein and member of the Ig superfamily—primarily expressed on T cells, some NKT cells, and thymocytes during T-cell differentiation. Binding of an anti-CD3 monoclonal antibody to CD3 stimulates T …

The OKT3 antibody reacts with an extracellular conformational epitope on the ~20 kDa CD3ε subunit of the human T cell receptor (TCR)/CD3 complex, which is expressed on the surface of ~95% of mature T cells and NKT cells, and variably on thymocytes.