ABSTRACT
An acidic domain (AD) of gp130 was previously found to interact with the Src family kinase (SFK) Hck. Here, the influence of myristoylated peptides derived from this AD was assessed in the mouse myeloma cell line, 7TD1. The IL-6-dependent growth of 7TD1 cells was reduced by approximately 75%, if 100 microM of myristoylated 18mer peptide (18AD) was included in the growth medium, but was unaffected by a control peptide with scrambled sequence (18sc). A similar differential inhibition by peptides 18AD and 18sc was observed for the erythropoietin-dependent growth of BaF-EH cells expressing chimeric erythropoietin receptor-gp130 and human Hck and for the human myeloma cell line INA-6. While the peptide 18AD concentration inhibiting 50% was approximately 30 microM in 7TD1 and BaF-EH cells, peptide 18AD did not significantly inhibit growth of IL-6-independent MM1.S myeloma and OKT1 hybridoma cells or of BaF-EH cells supplied with IL-3. Treatment with 100 microM peptide 18AD caused the same degree or 60% of apoptosis induction as IL-6 deprivation in 7TD1 or INA-6 cells, respectively. Co-immunoprecipitation experiments revealed that peptide 18AD interfered with the association of Hck and gp130 in 7TD1 lysates in a concentration-dependent manner. IL-6-treatment of INA-6 cells induced the kinase activities of Fyn, Lyn and Hck, but not Src, and the IL-6-induced SFK activities were inhibited by peptide 18AD. Expression in 7TD1 cells of a kinase-inactive Hck mutant (K269R) elicited a dominant-negative effect on cell number increases providing further evidence that SFKs are required for gp130 signalling in myeloma cells.
Subject(s)
Cytokine Receptor gp130/antagonists & inhibitors , Interleukin-6/antagonists & inhibitors , Multiple Myeloma/enzymology , Peptide Fragments/pharmacology , src-Family Kinases/antagonists & inhibitors , Amino Acid Sequence , Animals , Apoptosis/drug effects , Biological Transport , Cell Cycle/drug effects , Cell Line , Cell Line, Tumor , Cell Proliferation , Cytokine Receptor gp130/chemistry , Cytokine Receptor gp130/metabolism , Cytokine Receptor gp130/pharmacology , Humans , Mice , Molecular Sequence Data , Multiple Myeloma/pathology , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Proto-Oncogene Proteins c-hck/metabolism , STAT3 Transcription Factor/metabolism , src-Family Kinases/metabolismSubject(s)
Monomeric GTP-Binding Proteins/metabolism , Two-Hybrid System Techniques , Cloning, Molecular , DNA Primers/genetics , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression , Gene Library , Genetic Vectors , Humans , Monomeric GTP-Binding Proteins/genetics , Plasmids/genetics , Protein Binding , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Transformation, Genetic , cdc42 GTP-Binding Protein/genetics , cdc42 GTP-Binding Protein/metabolismABSTRACT
The results of ++clinico-serological examination of 81 subjects with meningeal diseases are given; among them 53 had tuberculous meningitis. The authors applied complement fixation (CFT) and indirect hemagglutination tests (IHT) with tuberculin. The high diagnostic significance of CFT and low efficiency of IHT were established in tuberculous meningitis detection. It is expedient to determine simultaneously the antituberculous antibodies in the blood serum and cerebrospinal fluid of the examined patients. Simultaneous performance of CFT during the follow-up increases its diagnostic potentialities to 88.6%. Detection of complement-binding antibodies only in CFT is, in most cases, a sign of isolated tuberculous meningitis. Detection of specific antibodies only in the blood serum of tuberculous meningitis patients is an indirect evidence of generalized process.
