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T Russo

Publications and source records attributed to T Russo.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Novel autocrine and paracrine loops of the stem cell factor/chymase network.

BACKGROUND: The aim of this study was to investigate whether the secretory granules of human mast cells store stem cell factor (SCF). We also addressed the question whether mast cell chymase, a chymotrypsin-like protease, also present in the secretory granules of human mast cells cleaves SCF at the peptide bound between Phe 158 and Met159. METHODS: The skin samples were obtained from patients with mastocytosis, undergoing skin biopsy for diagnostic purposes. Mast cells were isolated and purified from human lung parenchyma (human lung mast cells, HLMC) by countercurrent elutriation followed by discontinuous Percoll density gradient. SCF contents of human mast cells were assessed for immunoreactive SCF by ELISA. Western blot analysis of SCF and its cleavage products were performed with the MoAb anti-SCF 7H6. SCF and its proteolytic fragment were characterized by electrospray mass spectrometry (ES/MS). RESULTS: SCF is present in the secretory granules of human skin and lung mast cells. Immunoreactive SCF (iSCF) was detected in the cell lysates of HLMC, but not in basophils. iSCF was rapidly (3 min) released after challenge with anti-IgE, and iSCF in supernatants rapidly declined after 30 min. ES/MS analysis of rhSCF1-166 treated with recombinant human chymase showed a polypeptide of 17,977.1+/-0.6 Da and a minor component of 697.4+/-0.1 Da generated by specific cleavage at Phe159. SCF1-166 and SCF1-159 similarly activated HLMC and potentiated anti-IgE-induced activation of these cells. The cleavage product SCF160-166 had no effect on mast cells. Western blot analysis of supernatants of anti-IgE activated HLMC incubated for various intervals with rhSCF1-166 showed that rhSCF1-166 was converted to a faster-migrating form with a molecular weight compatible with SCF1-159 and to several SCF species. CONCLUSION: SCF is stored in human mast cell secretory granules and is immunologically released by mast cells. SCF1-166 is rapidly cleaved by chymase and other proteases to several SCF species.

Autocrine Communication↗
PubMedDate not supplied

Effects of interferon beta, cyclophosphamide and azathioprine on cytokine profile in patients with multiple sclerosis.

We assessed the in vitro effects of interferon beta-1b (IFNbeta-1b), cyclophosphamide (CY), and azathioprine (AZA) alone and of the combination of IFNbeta-1b with CY or AZA on the production of Th1 and Th2 cytokines in 10 patients with multiple sclerosis. Cytokine levels were determined at baseline and after stimulation with IFNbeta-1b, CY, and AZA alone or with the combination of IFNbeta-1b with CY or AZA. The combination of IFNbeta-1b with CY resulted in a statistically significant decrease in the production of interleukin-2 (IL-2) (P=0.003) and tumor necrosis factor alpha (TNF-alpha) (P=0.03). An additive effect on the production of interferon gamma (IFN-gamma) (P=0.2) and interleukin-10 (IL-10) (P=0.6), and a positive interaction on the production of interleukin-4 (IL-4) (P=0.08) were observed although the findings were not statistically significant. The combination of IFNbeta-1b with AZA resulted in a significant negative effect on the production of IL-2 (P=0.006), whereas TNF-alpha (P=0.02), IFN-gamma (P=0.03), IL-4 (P=0.2), and IL-10 (P=0.3) were not statistically impacted. Our data show that CY was able to improve the effects of IFNbeta-1b on the ratio of Th1/Th2 cytokines.

Adult↗
PubMedDate not supplied

A mouse tRNA pseudogene derived from a tRNA(Trp) coding sequence.

The identification and characterization of a mouse tRNA(Trp) pseudogene is reported. A synthetic oligonucleotide (31 mer), identical with the 3' half of a tRNA(Trp), was used to examine three mouse lambda clones that are known to contain clusters of tRNA genes. A fragment of one of these lambda clones strongly hybridizes to the oligonucleotide; the sequence of this region shows the presence of a gene significantly homologous to the chick tRNA(Trp). However two point mutations and a three base deletion prevent the folding of a possible transcript of this gene. The presence of a conserved promoter sequence for RNA polymerase III, that should allow the transcription of this gene, does not ensure the transcription of the gene, at least in our in vitro system.

Animals↗