Mycophenolic acid and intravenous immunoglobulin exert an additive effect on cell proliferation and apoptosis in the mixed lymphocyte reaction.
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.
Sharma
Kavita G
KG
Transplant Immunology Laboratory, Comprehensive Transplant Center, Cedars-Sinai Medical Center/UCLA School of Medicine, 8700 Beverly Blvd., Los Angeles, CA 90048, USA.
Radha
Raju
R
Pao
Andy
A
Amet
Nurmamet
N
Baden
Lara
L
Jordan
Stanley C
SC
Toyoda
Mieko
M
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
D018941:Antigens, CD19; D017252:CD3 Complex; D016756:Immunoglobulins, Intravenous; D007166:Immunosuppressive Agents; D009173:Mycophenolic Acid