Lymphocyte chemoattractant factor (LCF) is a lymphocyte cell product that stimulates migratory response in CD4+ lymphocytes, monocytes, and eosinophils. In concert with its activity, LCF induces human T-lymphocyte expression of interleukin 2 receptor. Here we describe the molecular cloning cDNA encoding LCF. It novel no significant homology to any previously described cytokine families. There an absolute requirement for both autoaggregation monomers membrane-expressed CD4 molecules...

Interleukin-16, a proinflammatory cytokine produced in CD8⁺ lymphocytes, is synthesized as precursor protein (pro-IL-16). It postulated that the C-terminal region of pro-IL-16 cleaved, releasing bioactive IL-16. To characterize IL-16 cleavage, we transfected COS cells with cDNA encoding ∼50-kDa form pro-IL-16. Transfected released ∼20-kDa cleavage product shown to consist 121 residues by immunoblotting and amino acid sequencing. Cleaved IL-16, but not pro-IL-16, exhibited...

Lymphocyte chemoattractant factor (LCF) is a tetrameric glycoprotein of 56,000 relative molecular mass produced by activated T lymphocytes. LCF binds to CD4 and has previously been found stimulate migration CD4+ lymphocytes monocytes. Because human eosinophils, like cells monocytes, express CD4, we examined functional responses eosinophils LCF. Recombinant (rLCF) expressed in COS was purified on affinity column. Migration elicited rLCF at low concentrations: the 50% effective dose (ED50)...

Abstract The function of the T4 antigen, a marker for differentiated T cell subset, is not well understood. Our previous observation that chemoattractant human lymphokine, lymphocyte factor (LCF), which selectively induces motile responses in unactivated T4+ lymphocytes, led us to investigate whether LCF could also induce activation. Because acts on cells, we next determined antigen has this LCF-induced cellular A migratory response induced by divalent anti-T4 antibody, but corresponding Fab...

Sera were obtained from the venous effluents of cold-challenged arms patients with idiopathic cold urticaria without plasma or serum cryoproteins; these sera exhibited increased neutrophil chemotactic activity alterations complement system. A two- to fourfold augmentation base-line immersed extremity began within 1 min, peaked at 2 and returned levels 15 whereas there was no change in control arm. The augmented specimens challenged arm each patient appeared a high molecular-weight region, as...

Abstract Eosinophils and CD4+ lymphocytes are preferentially recruited into sites of allergic inflammation. A role for eosinophils in the recruitment has not been defined. We studied capacity human to release chemoattractants T lymphocytes. Supernatants cultured contained chemoattractant activity lymphocytes, which was predominantly due IL-16 (lymphocyte factor) RANTES. With neutralizing Abs, eosinophil-derived lymphocyte chemotactic diminished by a mean (+/- SEM) 60 +/- 3% with polygonal...

CD4+ T cell infiltration is known to occur in tissues at sites of mast activation. The molecules produced and released by cells that account for this lymphocyte accumulation are poorly characterized. Here we report a chemoattractant cytokine, IL-16, stored preformed bone marrow-cultured human line, HMC-1, as demonstrated intracytoplasmic cytokine staining flow cytometry, lung cells, detected immunohistochemistry. In response the anaphylatoxin, C5a, or PMA treatment, IL-16 mRNA transcripts...

Histamine is known to trigger the release of interleukin (IL)-16 from human CD8⁺ cells. However, individual roles presently histamine receptor subtypes (H₁-H₄) in this inflammatory response have not been fully characterized. stimulation T lymphocytes purified peripheral blood led a 5- 8-fold increase basal IL-16 within 24 h, and was significantly blocked by H₂-selective antagonist, cimetidine, or thioperamide, an antagonist H₃...

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Accumulation of CD4+ interleukin (IL)-2R+ lymphocytes in the airways asthmatics is generally attributed to presence chemoattractant cytokines. The precise mechanism for initiation earliest lymphocyte infiltration and activation unknown. In this study, we describe first time activity bronchoalveolar lavage (BAL) fluid obtained from 6 h after antigen challenge. majority at early point represented by IL-16 (lymphocyte factor), a cell-specific growth factor. addition IL-16, macrophage...

At sites of inflammation, mononuclear cells are in close contact with aggregated platelets. Although the physiologic role this association is not clear, proximity suggests that platelet-derived mediators may play a chemoattraction T lymphocytes. In current study we investigated serotonin receptor-bearing lymphocyte modulation cell migration. Serotonin-stimulated human blood secrete chemoattractant activity selective for CD4+ cells. This was observed within 2 h exposure to and blocked by type...

Abstract Human T cell leukemia virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic, progressive neurologic disease characterized by marked degeneration of the spinal cord and presence infiltrating CD8+ cells macrophages. HAM/TSP patients have very high frequencies HTLV-I-specific CTL in peripheral blood cerebrospinal fluid. In this study, we show that also elevated levels produce intracellular IFN-gamma. To address potential role soluble mediators...

Abstract Histamine has an important role in regulation of immune response which is mediated by differential expression four distinct receptors, H1R–H4R. H1R and HR2 have previously been shown to be involved with modulation lung inflammation. H4R also expressed on inflammatory cells; therefore, we investigated the potential development allergic asthma a murine model. We determined that agonist 4-methylhistamine when delivered intratracheally before Ag challenge mitigated airway...

We have recently described the cDNA and predicted protein structure of a natural soluble CD4 ligand, IL-16. IL-16 is chemotactic for CD4+ T cells induces functional IL-2 receptors in cells. The binding to results activation p56(lck), whose adaptor function essential response. Subsequently, increases intracellular Ca2+ phosphatidylinositol 1,4,5-trisphosphate occur, as does translocation kinase C from cytosol membrane. Because similarities between these signals functions those noted ligand...

We have reported previously that histamine induces the release of CD4+ cell-specific lymphocyte chemoattractant factor (LCF) into culture supernatants CD8+ cells between 1 and 4 h following stimulation. To determine mechanism histamine-induced secretion LCF, we evaluated effects inhibitors gene transcription translation on LCF production, determined stimulation mRNA induction stability. The from was not associated with de novo synthesis protein, nor did an effect or stability mRNA....

Growth factor receptors for T lymphocytes, such as interleukin 2 and insulin, are present on activated but not resting lymphocytes. We sought to determine if insulin-like growth I (IGF-I) could act a human cells characterize its receptor cells. Recombinant IGF-I induced two separate functions. It was chemotactic increased incorporation of tritiated thymidine into both unactivated (resting) mitogen-activated High-affinity 125I-IGF-I binding saturable with an apparent Kd 1.2 +/- .6 X 10(-10) M...

Abstract As a natural ligand for CD4, IL-16 has been shown to preferentially induce migration in Th1 cells, and, long-term cultures with IL-2, facilitates the expansion of CD4+CD25+ cells. In addition, an immunomodulatory role asthmatic inflammation, as exogenous administration significantly reduces inflammation and airway hyperreactivity. The mechanism this, however, is not clear. Based on its functional characteristics potential role, we investigated ability recruit influence development T...