Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Interleukin-16”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Early identification of interleukin-16 (lymphocyte chemoattractant factor) and macrophage inflammatory protein 1 alpha (MIP1 alpha) in bronchoalveolar lavage fluid of antigen-challenged asthmatics.

Accumulation of CD4+ interleukin (IL)-2R+ lymphocytes in the airways of asthmatics is generally attributed to the presence of chemoattractant cytokines. The precise mechanism for the initiation of the earliest CD4+ lymphocyte infiltration and activation is unknown. In this study, we describe for the first time the presence of lymphocyte chemoattractant activity in the bronchoalveolar lavage (BAL) fluid obtained from asthmatics 6 h after antigen challenge. The majority of the chemoattractant activity at this early time point is represented by IL-16 (lymphocyte chemoattractant factor), a CD4+ cell-specific chemoattractant and growth factor. In addition to IL-16, macrophage inflammatory protein 1 alpha (MIP1 alpha) chemotactic bioactivity was detected in significant levels. While IL-16, MIP1 alpha, and IL-8 were all identified by enzyme-linked immunosorbent assay, the great majority of the lymphocyte chemoattractant activity in the BAL fluid after antigen challenge is attributable to IL-16 and MIP1 alpha. There were no detectable levels of IL-16 nor MIP1 alpha in BAL fluid of antigen-challenged normal subjects nor atopic nonasthmatics nor in saline-challenged lobes from the asthmatics. The identification of multiple lymphocyte chemoattractants early after antigen challenge suggests a complex cellular, as well as chemoattractant cytokine, profile in initiating the CD4+ T cell-mediated inflammatory process that is specific for the atopic asthmatic phenotype.

Adult↗

Targeting IL-16 to Protect Angiotensin II-induced Hypertension and Renal Injury.

BACKGROUND: T cells are critical in the pathogenesis of hypertension. IL (interleukin)-16 is primarily produced and secreted by T cells; however, its role in hypertension remains unclear. METHODS: Serum samples from patients with hypertension were collected and analyzed using ELISA. A mouse model of Ang II (angiotensin II)-induced hypertension was established, and the role of IL-16 was investigated. RESULTS: IL-16 expression was elevated in patients with hypertension and positively correlated with both systolic and diastolic blood pressure. In Ang II-induced hypertensive mice, IL-16 expression was significantly upregulated in serum, kidney, and aortic tissues. IL-16-neutralizing antibody reduced both systolic and diastolic blood pressure in response to Ang II. Histological analyses revealed that renal injury and vascular remodeling were attenuated after IL-16 neutralization. Mechanistically, T-cell-derived IL-16 enhanced CD4+ (cluster of differentiation 4) T helper 1 cell function and mediated crosstalk with macrophages to stimulate inflammatory responses via activation of NF-κB (nuclear factor kappa B) and MAPK (mitogen-activated protein kinase) pathways. Conditioned medium from macrophages primed with IL-16-treated T helper 1 cells promoted smooth muscle cell proliferation and exacerbated endothelial cell damage during hypertension progression. CONCLUSIONS: Collectively, these findings indicate that T-cell-derived IL-16 exacerbates Ang II-induced hypertension and associated organ damage by promoting a T helper 1-macrophage-driven proinflammatory response.

Hypertension↗

Phenotypic determination of T-lymphocytes responding to chemotactic stimulation from fMLP, IL-8, human IL-10, and epidermal lymphocyte chemotactic factor.

Human T lymphocytes were collected after they had migrated towards N-formyl-methionyl-leukylphenylalanine (fMLP), rIL-8, human IL-10 (hIL-10), and epidermal lymphocyte chemotactic factor (ELCF). They were stained for determination of their phenotype by FACS analysis using anti-CD4, -CD8, -CD18, -CD45R0 and OPD4 antibodies. Human IL-10 increased the percentage of CD8+ T lymphocytes in the migrating cell population by 152% compared with cells migrating towards the medium and decreased the number of CD4+ T lymphocytes by 79%. ELCF increased the number of CD4+ T lymphocytes by 18%, and the number of CD45R0+ T lymphocytes by 52%, while the number of CD8+ T lymphocytes was decreased by 20%. rIL-8 increased the number of CD4+ T lymphocytes and decreased the CD8+ T lymphocytes. The distribution of the different subpopulations of T lymphocytes was not changed significantly by fMLP. The observed changes in the phenotypes did not occur when incubating T lymphocytes with the chemotaxins. Our observations demonstrate that individual chemotactic factors will attract specific subsets of T lymphocytes. They may help to explain the predominance of memory T lymphocytes (CD4R0+, CD4+) in allergic contact dermatitis and certain other skin diseases. They also confirm the results of a recent study, that showed hIL-10 to be selectively chemotactic for CD8+ T lymphocytes.

Antigens, CD↗

Epidermal lymphocyte chemotactic factor specifically attracts OKT4-positive lymphocytes.

Epidermal lymphocyte chemotactic factor (ELCF) from skin overlying a positive tuberculin reaction was compared with the chemoattractants leukotriene B4 (LTB4), N-formyl-methionyl-leukyl-phenylalanine (FMLP), and complement split product C5a (C5a). The chemotactic assay used is a modified Boyden chamber technique. The lymphocytes were subsets of T lymphocytes from healthy young individuals first separated by flotation of E rosettes on Isopaque Ficoll followed by incubation of T cells with anti-CD4 and anti-CD8 monoclonal antibodies and further separation using fluorescence-activated cell sorting. ELCF specifically attracted OKT4+ lymphocytes, while LTB4, FMLP, and C5a induced significant migration in both OKT4+ and OKT8+ lymphocytes without any clear difference between the various chemoattractants or cell populations. We found no blocking of the chemotactic capacity of ELCF when we added antibodies towards IL-1 alpha and IL-1 beta to the chemotactic assay. Further recombinant IL-1 alpha and Il-1 beta did not induce any chemotactic response. Our observation may be of significance in explaining the predominance of OKT4+ cells in allergic contact dermatitis and certain other skin diseases.

CD4-Positive T-Lymphocytes↗

Inhibitors of membrane transmethylation reactions prevent the lymphocyte chemokinetic response.

The methylation of membrane phospholipids has been shown to occur following receptor-mediated activation of leukocytes. The present studies show that the human lymphocyte response to two positive chemokinetic signals (bradykinin and lymphocyte chemoattractant factor) can be interrupted by inhibitors of S-adenosyl-L-methionine-mediated transmethylation reactions. The chemokinetic response to the nonphysiologic stimulant colchicine is not affected. We speculate that phospholipid methylation accompanies receptor-mediated lymphocyte migration, and may facilitate activation of second messenger systems.

Adenine↗

Molecular and functional analysis of a lymphocyte chemoattractant factor: association of biologic function with CD4 expression.

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

Amino Acid Sequence↗

The CD4-associated tyrosine kinase p56lck is required for lymphocyte chemoattractant factor-induced T lymphocyte migration.

Lymphocyte chemoattractant factor (LCF) is a polypeptide cytokine which induces both cell motility and activation of T lymphocytes. These LCF-induced events demonstrate an absolute requirement for the cell surface expression of CD4. Because many CD4-mediated T lymphocyte activation events have been demonstrated to require the association of the src-related tyrosine kinase p56lck with the cytoplasmic domain of CD4, we examined the role of p56lck in LCF-induced lymphocyte migration in a murine T cell hybridoma line expressing transfected human CD4. LCF induces the catalytic activity of CD4 associated p56lck at chemoattractant concentrations of cytokine. Hybridoma cells that express CD4 with cytoplasmic point mutations which uncouple the CD4-lck association lack both lck enzymatic activity and chemotactic responses to LCF. The enzymatic activity of lck however does not appear to be required for CD4-mediated migratory signal. First, the protein tyrosine kinase inhibitor herbimycin A blocked LCF-induced p56lck activation but had no effect on the LCF-induced motile response. Second, T cell hybridomas expressing a chimeric receptor combining the extracellular domain of human CD4 and murine p56lck which lacked the kinase domain had a normal LCF-induced motile response. We conclude from these observations that CD4-lck coupling is essential for LCF-induced T lymphocyte migration but the motile response is independent of the enzymatic activity of CD4-associated p56lck.

Animals↗

CD4-mediated stimulation of human eosinophils: lymphocyte chemoattractant factor and other CD4-binding ligands elicit eosinophil migration.

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 to stimulate migration of CD4+ lymphocytes and monocytes. Because human eosinophils, like T cells and monocytes, express CD4, we examined functional responses of eosinophils to LCF. Recombinant LCF (rLCF) expressed in COS cells was purified on a CD4 affinity column. Migration of eosinophils was elicited by rLCF at low concentrations: the 50% effective dose (ED50) was 10(-12) to 10(-11) M, concentrations 100- to 1,000-fold lower than the ED50s for the recognized eosinophil chemoattractants C5a and platelet-activating factor. Two other ligands which bound to CD4, human immunodeficiency virus-1 envelope glycoprotein gp120 and monoclonal antibody OKT4, also stimulated eosinophil migration. Monovalent OKT4 Fab competitively inhibited eosinophil responses to rLCF. rLCF did not influence other functional responses of eosinophils tested, including degranulation, superoxide generation, leukotriene C4 production, in vitro survival, or surface expression of the adherence receptor CR3 (CD11b), human histocompatibility leukocyte antigen DR, or interleukin 2 receptor p55 (CD25). We conclude that CD4 on eosinophils is capable of transducing a migratory stimulus and serves as a receptor for a chemoattractant lymphokine LCF. T cell-derived LCF may contribute to recruitment of eosinophils and CD4+ mononuclear cells concomitantly at inflammatory reactions.

CD4 Antigens↗

Epidermis and lymphocyte interactions during an allergic patch test reaction. Increased activity of ETAF/IL-1, epidermal derived lymphocyte chemotactic factor and mixed skin lymphocyte reactivity in persons with type IV allergy.

Recently, we have found an increased activity of epidermal-derived thymocyte-activating factor (ETAF/IL-1) and epidermal lymphocyte chemotactic factor (ELCF) in epidermis overlying a positive tuberculin skin reaction. In the present study, we investigated 20 patients with confirmed or suspected allergic contact dermatitis by using the suction blister technique before and during patch testing. The ETAF/IL-1 was found in epidermis before patch testing. Its presence increased 2.8-fold in epidermis overlying a positive patch test compared with pretesting values. This increase was statistically significant. Interestingly, nontested skin also showed a significant increase of ETAF/IL-1, which was 1.9-fold higher than pretest values. The ETAF/IL-1 activity in patch test areas was significantly correlated with the clinical response. ELCF is not present in epidermis from noneczematous persons. We observed a significant content of ELCF in three of seven patients with eczema prior to patch testing. After patch testing, all patients showed ELCF in epidermis. Nontested skin showed a 1.5-fold higher content of ELCF compared with pretest values, and in the test area ELCF was 1.8-fold higher. The increases were statistically significant. We performed mixed skin lymphocyte reactions in seven patients using epidermal cells from the patch test area. All patients with a positive patch test had an increased mixed skin lymphocyte reactivity compared with epidermis coming from a negative reaction.

Adult↗

Two distinct mechanisms involved in the infiltration of lymphocytes into tumors.

We have analyzed the mechanism controlling the infiltration of lymphocytes into tumor tissues. W3/25 (+) (helper/inducer phenotype) T cells obtained from tumor tissues of T-9 sensitized rats produced soluble factors. We demonstrated that the soluble factors were responsible for the infiltration of T lymphocytes into tumor tissues by using a modified Boyden chamber technique. We established a system in which we stained filters of the Boyden chamber by an immunoperoxidase technique, thus directly determining the phenotype of cells that had actually migrated into the filters in response to the soluble factors. Upon fractionation of soluble factors produced by W3/25 (+) T cells, four peaks of lymphocyte migration factor (LMF) activity were detected. Peaks B and C exhibited strong LMF activity and specifically attracted R1-10B5 (+) (suppressor/killer phenotype) T cells. Thus, the infiltration of R1-10B5 (+) T cells into tumor tissues was partly explained by LMF produced by tumor-infiltrating W3/25 (+) T cells. The expression of a putative receptor for LMF by lymphocytes may also influence the degree of lymphocyte infiltration into tumors.

Animals↗

Cytokine binding to CD4+ inflammatory cells: implications for asthma.

While LCF is present in BAL early after antigen challenge, we know little about its other potential effects beyond CD4+ T cell, monocyte, and eosinophil chemotaxis and monocyte and CD4+ T cell activation. The work described here focuses on the hypothesis that the secreted protein products of T cells participate in the airway inflammatory process that underlies human asthma, and in particular that LCF could play an early role because of the unusual responsiveness of LCF-producing T to histamine. To date, most studies have addressed the measurement of cytokines derived from CD4+ T cells (e.g., IL-2, IL-3, IL-4, IL-5, and GM-CSF) in the airways of asthmatics, and attempted to correlate the presence of protein or mRNA with the complexion of the inflammatory infiltrate. These studies have been based upon the reports that there are increased numbers of CD4+ T cells in the airways of asthmatics, and that the presence of eosinophils might correlate with the secretion of TH2-type cytokines like IL-3, -4, and -5. Using this information as a background, our work has approached the problem in an entirely different way. We have focused our attention on the early events in antigen-induced asthma that are responsible for CD4+ cell accumulation in the lung, including CD4+ T cells, eosinophils, and monocytes. We have attempted to identify mechanisms by which mast cell mediators, in particular histamine, might play a role in the secretion of chemotactic lymphokines that are selective for CD4+ cells by using CD4 itself as a chemotactic factor receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Lymphocyte chemokinetic factors derived from human tonsils: modulation by 1,25-dihydroxyvitamin D3 (calcitriol).

Although interleukin (IL)-2 may in part be responsible for lymphocyte accumulation to sites of active sarcoidosis, other cytokines that control such recruitment are not well characterized. Similarly, the pathogenic rationale for the ability of sarcoid macrophages to produce 1,25-dihydroxycholecalciferol (calcitriol) is not understood. We studied the release of chemokinetic lymphokines from human nylon wool-non-adherent tonsillar lymphocytes (HNTLs) employing a standard in vitro lymphocyte migration assay. If mitogen-stimulated HNTL supernatants were fractionated by high-performance liquid chromatography, five positive and one negative chemokinetic factors could be identified. The five lymphocyte chemoattractant factors (LCFs) ranged in mol wt from 5 to 35 kD and stimulated the in vitro migration of nonsensitized human lymphocytes by 200 to 500%. The LCFs appeared distinct from IL-2, IL-1, or gamma-interferon. Co-incubation of HNTLs with mitogen and 1 nM calcitriol prevented the production or release of two of the LCFs and significantly decreased the quantity of a third LCF. Calcitriol also resulted in the appearance of a second negative chemokinetic factor, lymphocyte migration inhibitory factor (LyMIF). Combined with our previous studies demonstrating that calcitriol interferes with IL-2-induced lymphocyte migration, these results provide a rationale for an anti-inflammatory role for calcitriol in sarcoidosis and other granulomatous disorders. These experiments also demonstrate that the control of lymphocyte recruitment to inflammatory foci is multifactorial.

Adolescent↗

Lymphocyte chemoattractant factor induces CD4-dependent intracytoplasmic signaling in lymphocytes.

At present, a naturally occurring soluble ligand for CD4 has not been well described. There is much evidence to indicate that MHC class II molecules can bind to CD4; however, binding of intact class II molecules under physiologic conditions has been difficult to demonstrate. We investigated whether a previously reported human lymphokine, lymphocyte chemoattractant factor (LCF), which was described for its effects on human CD4+ lymphocytes and monocytes, could associate directly with CD4 and induce the generation of second messengers. In the present study, we demonstrate that CD4 affinity-purified natural and recombinant LCF induced a rise in intracellular calcium and increased inositol trisphosphate generation in normal human CD4+ lymphocytes and murine T cell hybridomas infected to express human CD4. Cell lines lacking human CD4 or expressing human CD4 molecules that lack the intracytoplasmic domain did not demonstrate a change in either calcium or inositol trisphosphate. The effect of LCF was blocked by coincubation with either anti-CD4 antibody or Fab fragments from anti-CD4 antibody. These studies demonstrate direct interaction of a lymphokine with CD4 and generation of second messengers as a result of the interaction.

CD4 Antigens↗

Imbalance of T cell immunoregulatory subsets in primary IgA nephropathy.

The peripheral blood distribution of T cell subsets was evaluated in a group of patients with primary IgA nephropathy (IgAN). Results showed that the frequency of helper (CD4+) and suppressor (CD8+) T lymphocytes in IgAN overlapped that seen in healthy blood donors. In addition, the helper T cell subset (CD4+ CDW29+ and CD4+ CD45R+ cells, respectively) proportion was normal, while with particular reference to suppressor T cell subpopulations, a significant decrease of CD8+ CD11+ lymphocytes (the true suppressor cells) was observed in IgAN. These data were further confirmed by the demonstration that monocyte chemotactic responsiveness triggered by lymphocyte-derived chemotactic factor (LDCF), a lymphokine released by CD8+ CD11- cells, was higher in IgAN than in controls. These data suggest that the low frequency of CD8+ CD11+ cells may be responsible for the impaired T cell immunoregulatory activity in patients with IgAN.

Adult↗

[Identification of protein products of the operon for leukocytosis (lymphocytosis)-stimulating factor from Bordetella pertussis cloned in Escherichia coli].

The hybrid plasmid pRH119 was constructed on the basis of vector plasmid pUC19 and shown to carry Bordetella pertussis PT operon in the same transcriptional orientation with the lac-promoter of the vector plasmid. Expression of PT genes in E. coli cells harbouring pRH119 was not registered. Weak expression of PT genes was found by immunoscreening of recombinant clones in situ with antiserum against PT when PT genes were put closer to lac-promoter. 0.95 kb SalGI fragment was deleted from pRH119. The derivative plasmid pRH122 was digested by SalGI and the ends were polymerized to "blunt" by polIK and ligated. The obtained plasmid pRH122K was deleted for 40 bp in XbaI site by Bal31 deletion. The lysate of E. coli cells harbouring the resulting plasmid pRH134 passed through Sepharose 4B with covalently bound immunoglobulins from antiserum against PT. The eluted protein contains S2 multimers identified by immunoblotting. The experiments with CHO-cells and active mice protection have shown the absence of S2 multimers protectiveness.

Bacterial Proteins↗