Lajos Dr. Tarcsay

Generation and Characterization of a Monoclonal Antibody (1C5) To Human Migration Inhibitory Factor (MIF)

A monoclonal antibody was raised in mice against human MIF of the Mr 14,000 kd, produced by Concanavalin A-stimulated peripheral blood mononuclear cells. A hybridoma (1C5) secreting an IgG 1 antibody was selected which binds, yet does not neutralize MIF in the macrophage migration assay. MIF activity may be released from immobilized antibodies by acidic buffer elution. The eluate consists of three major bands at Mr 8,000, 14,000 and 28,000 as revealed by SDS-polyacrylamide gel electrophoresis and molecular sieve chromatography (HPLC). By radioimmunoassay and enzyme-linked immunoassay, it could be shown that the antibody binds material with isoelectric points of 4.5 to 5.0 and of 3.0, which coincides precisely with the biological activities. Similar congruencies between the distribution of biologically reactive and binding material were found in molecular sieve and ion exchange chromatography. It is concluded that the antibody 1C5 reacts with most molecular weight entities of MIF which seem to be structurally related and which display similar characteristics as described for guinea pig and mouse MIF.

Pharmacokinetics and immunomodulatory effects on monocytes during prolonged therapy with liposomal muramyltripeptide

The macrophage activator muramyl tripeptide-phosphatidyl ethanolamine (MTP-PE) was infused in liposomal form in 14 metastatic cancer patients (4 mg i.v. during 30 min twice weekly for 12 weeks). Clinical, pharmacokinetic and immunological parameters were studied before and 0.5, 2, 4, 24 and 72h after start of drug infusion in week 1, 4, 8 and 12. No tumor regressions were seen. Tumors progressed in 11 patients, in 4 of them within 2 months; 3 patients had stable disease. The intensity and frequency of side effects (fever and nausea) diminished from week 1 to 12. The rate of disappearance of total and free MTP-PE from blood was rapid and mean serum concentration-time curves remained unchanged throughout 12 study weeks. MTP-PE caused a marked increase of serum TNFa, IL-1 receptor antagonist (IL-1ra) and IL-6 in week 1, but not thereafter. In contrast, MTP-PE caused a persistent, 2-fold increase in serum neopterin and young forms of granulocytes (bands) during week 1 to 12. Before therapy, monocyte tumor cytotoxicity and in-vitro monocyte derived TNFa, IL-1Β and IL-6 production were low in 9 patients (group L, <15%) and high in 5 patients (group H, >40%). Monocyte cytotoxicity and in-vitro cytokine production was transiently enhanced in week 1 in group L, it declined under therapy in group H. In conclusion, MTP-PE induced marked initial immunomodulation; the extent of the ex vivo monocyte cytokine and tumor cytotoxic response was dependent on pretherapy cell activity. A decrease of the cytokine and IL-1ra response during prolonged therapy contrasted with a persistent increase of neopterin and juvenile blood granulocytes. The long lasting biologic effects may be relevant to direct future clinical studies with liposomal MTP-PE in an adjuvant setting.