University:
American Career College
Course:
MICR-112 | General Microbiology
Academic year:

2020
Views:

387

Pages:

11
Author:

kOmega

Monoclonal antibodies MUROMONAB CD3  Murine monoclonal Ab against CD3.  Mechanism  of action- Binds to CD3, a component of T-cell receptor complex involved in antigen recognition and cell signaling & proliferation.  Use- As induction therapy together with corticosteroid & azathioprine in sequential regimen for organ transplantation.  Postpone potential nephrotoxicity and hepatotoxicity of cyclosporine.  Toxicity- Initial doses of muromonab CD3 are associated with flu like symptoms: chills, rigor and wheezing (Cytokine release syndrome).  Occasionally Aseptic meningitis, Intragraft thrombosis, Pulmonary edema, Seizures and a Shock like state are produced.  High dose of corticosteroid pretreatment reduces the reaction. Anti IL-2 receptor antibody Daclizumab  & Basiliximab Bind to IL-2 receptor with high affinity on surface of activated T cells.  Block IL-2 mediated T cell activation.  Use- prophylaxis of acute organ rejection & maintenance of graft.  Toxicity- Anaphylaxis, Opportunistic infections. Alemtuzumab  Monoclonal antibody binds to CD52 – expressed on lymphocytes, monocytes, macrophages.  Extensive lympholysis- prolonged T & B cell depletion.  Use- CLL, Bone marrow transplantation, Renal transplantation  Toxicity- Opportunistic infections. Anti –D immunoglobulin  Human IgG having high titre of antibodies against Rh (D) antigen.  It binds the Rh Ag, inhibit antibody formation in Rh negative individuals.  It is used for prevention of postpartum/ post abortion formation of antibodies in Rh negative female who delivered or aborted an Rh positive baby/ foetus. Administered within 72 hrs of delivery/ abortion  It prevents Rh hemolytic disease in future offspring.  It has also been given at 28th week of pregnancy.  Never be given to Rh positive individuals.  Antithymocyte globulin (ATG)  Polyclonal Ab purified from horse or rabbit immunized with human thymic lymphocytes.  Mechanism of action-  Binds to T lymphocytes and depletes them.  Potent immunosuppressant.  Use- Suppress acute allograft rejection episodes especially in steroid resistant cases or is combined with them.  Toxicity- May produce serum sickness or anaphylaxis. Anti –TNF Agents Infliximab  Chimeric monoclonal antibody against TNF α.  Uses- Rheumatoid Arthritis, Crohn’s Disease, Psoriasis, Ankylosing Spondylosis. Etanercept  Fusion protein, neutralize both TNF α and TNF β  Prevent activation of macrophages & T cells  Uses- Rheumatoid Arthritis, Ankylosing Spondylosis, Psoriasis Sites of Action of Selected Immunosuppressive Agents on T-Cell Activation DRUG SITE OF ACTION Glucocorticoids Glucocorticoid response elements in DNA (regulate gene transcription) Muromonab CD3T-cell receptor complex (blocks antigen recognition) Cyclosporine Calcineurin(inhibits phosphatase activity) Tacrolimus Calcineurin(inhibits phosphatase activity) Azathioprine Deoxyribonucleic acid (false nucleotide incorporation) Mycophenolate Mofetil Inosinemonophosphate dehydrogenase (inhibits activity) Daclizumab, Basiliximab IL-2 receptor (block IL-2-mediated T-cell activation) Sirolimus Protein kinase involved in cell-cycle progression (mTOR) (inhibits activity)