title: Mycophenolic acid and intravenous immunoglobulin exert an additive effect on cell proliferation and apoptosis in the mixed lymphocyte reaction.
abstract: BACKGROUND
  Intravenous immunoglobulin (IVIG) has known immunomodulatory effects in autoimmune diseases and transplantation and is commonly used in desensitization protocols and for treatment of antibody-mediated rejection (AMR). IVIG inhibits the MLR and induces apoptosis in immune cells. Mycophenolate mofetil inhibits immune cell proliferation and is an effective immunsuppressive agent. Here, we examined the possible synergistic effects of combined MMF and IVIG on cell proliferation and apoptosis induction in the MLR.
  
  
  METHODS
  Two-way MLRs were performed with mycophenolic acid (MPA), IVIG and both in combination. Cell proliferation and apoptosis were detected by 3H-thymidine incorporation and Annexin flow cytometry, respectively.
  
  
  RESULTS
  IVIG (1-10mg/ml) or MPA (0.01-0.25 microg/ml) alone inhibited cell proliferation in the MLR in a dose-dependent manner. MPA at 0.01-0.03 microg/ml showed minimal inhibition, but the addition of 5 and 10mg/ml IVIG increased inhibition significantly (p<0.05) to 43% and 64%, respectively. Annexin V positive cell number was significantly higher in IVIG (5mg/ml) treated CD19+ cells (68+/-13% vs. 43+/-12%, p=0.001) compared to untreated cells and to a lesser degree in CD3+ cells (29+/-7% vs. 25+/-10 %, p=0.02). MPA (0.25-10 microg/ml) alone neither induced nor inhibited apoptosis. Addition of MPA had no effect on apoptosis induced by IVIG.
  
  
  CONCLUSIONS
  1) Combining low concentrations of IVIG (5-10 mg/ml) and MPA (0.01-0.03 microg/ml)has an additive effect on inhibition of cell proliferation in the MLR. 2) MPA alone neither induces nor inhibits apoptosis in T or B cells in the MLR, and has no effect on apoptosis induced by IVIG. These in vitro observations may have implications for modification of therapeutic approaches to protocols utilizing IVIG for desensitization and immune modulation.
authors.affiliation: Transplant Immunology Laboratory, Comprehensive Transplant Center, Cedars-Sinai Medical Center/UCLA School of Medicine, 8700 Beverly Blvd., Los Angeles, CA 90048, USA.
authors.forename: Kavita G
authors.initials: KG
authors.lastname: Sharma
authors.forename: Raju
authors.initials: R
authors.lastname: Radha
authors.forename: Andy
authors.initials: A
authors.lastname: Pao
authors.forename: Nurmamet
authors.initials: N
authors.lastname: Amet
authors.forename: Lara
authors.initials: L
authors.lastname: Baden
authors.forename: Stanley C
authors.initials: SC
authors.lastname: Jordan
authors.forename: Mieko
authors.initials: M
authors.lastname: Toyoda
mesh_terms: D018941:Antigens, CD19 / Q000096:biosynthesis; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D017252:CD3 Complex / Q000096:biosynthesis; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D004357:Drug Synergism; D005434:Flow Cytometry; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000494:pharmacology*; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007959:Lymphocyte Culture Test, Mixed; D009173:Mycophenolic Acid / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014181:Transplantation Immunology
chemical_list: D018941:Antigens, CD19; D017252:CD3 Complex; D016756:Immunoglobulins, Intravenous; D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid