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Biomedical subjects

W W Cruikshank

Publications and source records attributed to W W Cruikshank.

At least 73 records · Page 4Linked to original sources
PubMed1995

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↗
PubMed1995

Induction of human monocyte motility by lysyl oxidase.

Lysyl oxidase highly purified from calf aorta was found to be a potent chemotactic agent for unstimulated human peripheral blood mononuclear cells, determined in in vitro assays in Boyden chambers. A typical chemotactic bell-shaped curve was observed, with a maximal migratory response of 237% of control occurring at 10(-10) M lysyl oxidase. The chemotactic response was prevented by prior heat inactivation of the enzyme, by treatment of the enzyme with beta-aminopropionitrile or ethylenediamine, which are active site-directed inhibitors of lysyl oxidase, and by a competing, lysine-containing peptide substrate of lysyl oxidase. The chemoattractant response to lysyl oxidases was characterized by both chemokinetic and chemotactic components. These results raise the possibility that extracellular lysyl oxidase may have important roles to play in biology in addition to its established function in the crosslinking of elastin and collagen.

Aminopropionitrile↗
PubMed1995

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↗
PubMed1995

The lymphocyte chemoattractant factor.

The LCF is a unique interleukin without significant homology to other interleukins or chemokines. It is a chemoattractant factor for all CD4+ cells and either uses CD4 as its receptor or utilizes a cell surface complex of molecules for which there is an absolute requirement for the presence of CD4. In addition to its chemoattractant activity, it is a growth factor for CD4+ T cells, inducing resting cells to enter G1, as evidenced by the expression of MHC II molecules and IL-2R. Once induced by LCF to express IL-2R, CD4+ T cells become competent to respond to LCF and progress through the cell cycle to proliferation. LCF's activity on CD4 cells defines a role for CD4 on the eosinophil and monocyte and broadens the scope of functions of CD4 on the T cell. In this regard it may have importance in human disease states that are characterized by increased numbers of activated CD4+ cells, such as sarcoidosis, rheumatoid arthritis, or asthma. Likewise, it may play a key role in monocyte and eosinophil chemotaxis into tissues, being important in the latter in concert with hematopoietic factors that increase the available eosinophil pool.

CD4 Antigens↗
PubMed1994

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↗
PubMed1994

Serotonin-stimulated aortic endothelial cells secrete a novel T lymphocyte chemotactic and growth factor.

Atherosclerotic lesions contain multiple cell types including smooth muscle cells, macrophages, and T lymphocytes. The development of an extralymphatic T lymphocyte focus of inflammation in this condition requires chemoattractant-induced cell migration and growth factor-induced cell activation. In a previous study, we described a novel 13-15-kDa T lymphocyte-specific chemotactic cytokine, endothelial cell-derived lymphocyte chemoattractant activity (ED-LCA), secreted by serotonin-stimulated bovine aortic endothelial cells that is distinct from previously identified endothelial cell-derived interleukins (IL) 1, 6, and 8. Because of the association between T lymphocyte chemotactic and growth factor activity, in the current study we investigated the effect of ED-LCA on T cell growth. We assessed its capacity to induce markers of the passage of T cells from the resting (G0) state into the G1 phase of the cell cycle, such as receptors for IL-2 (IL-2R) and transferrin (TFR) and class II major histocompatibility complex antigens (HLA-DR). Incubation of G0 freshly isolated human T lymphocytes for 48 h with chromatographically resolved, partially purified ED-LCA resulted in a threefold increase in expression of the p55 subunit of IL-2R, a threefold increase in TFR, and a twofold increase in HLA-DR. Passage into the G1 phase of the cell cycle was confirmed by cell cycle analysis employing acridine orange. Evaluation of CD4+ and CD8+ T cell subsets by double-antibody labeling demonstrated that the p55 subunit of IL-2R was induced in both T cell subsets. Although incubation of human T cells with ED-LCA alone did not induce proliferation, addition of exogenous IL-2 to T cells pulsed with ED-LCA for 24 h caused a proliferative response with a stimulation index of 3. By up-regulating functional cell surface receptors for IL-2, ED-LCA is a competence growth factor for T lymphocytes and primes them to respond to IL-2. By virtue of its effect on T cells, as a chemotactic and competence factor, this endothelial cell-derived mitoattractant could participate with other T cell growth factors like IL-2 in the recruitment and amplification of the extralymphatic T cell component of atherosclerosis.

Animals↗
PubMed1994

Secretion of a novel T-lymphocyte cytokine possessing both chemotactic and growth factor activity by serotonin-stimulated human aortic endothelial cells.

The development of an extralymphatic T-lymphocyte focus of inflammation requires chemoattractant-induced cell migration and growth factor-induced cell proliferation. In a previous study, we identified a novel 13- to 15-kDa T-lymphocyte-specific chemotactic cytokine, endothelial cell-derived lymphocyte chemoattractant activity (ED-LCA), secreted by serotonin-stimulated human aortic endothelial cells. Based on its physicochemical and functional characteristics and antibody inhibition studies, ED-LCA is distinct from previously identified endothelial cell-derived IL-1, IL-6, and IL-8. Because of the association between T-lymphocyte chemotactic and growth factor activity, in the current study, we investigated the effect of ED-LCA on T cell growth by assessing its capacity to induce markers of the passage of T cells from the resting (G0) state into the G1 phase of the cell cycle, such as receptors for IL-2 (IL-2R) and transferrin (TFR), and class II major histocompatibility complex antigens (HLA-DR). Incubation of G0 freshly isolated human T lymphocytes for 48 h with chromatographically resolved, partially purified ED-LCA resulted in a threefold increase in expression of IL-2R, a threefold increase in TFR, and a twofold increase in HLA-DR. Double antibody labeling demonstrated that IL-2R was induced in both CD4+ and CD8+ T cell subsets. Although incubation of human T cells with ED-LCA alone did not induce DNA synthesis, addition of exogenous IL-2 to T cells pulsed with ED-LCA for 24 h caused an increase in DNA synthesis with a stimulation index of 3.5. By up-regulating functional cell surface receptors for IL-2 on T lymphocytes and priming them to respond to exogenous IL-2, ED-LCA is a competence growth factor. By virtue of its effect on T cells, as a chemotactic and competence factor, this endothelial cell-derived mitoattractant could participate with other T-cell growth factors like IL-2 in the generation of an extralymphatic T-lymphocyte inflammatory response.

Adult↗
PubMed1994

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↗
PubMed1994

CD4 modulation of noninfected human T lymphocytes by HIV-1 envelope glycoprotein gp120: contribution to the immunosuppression seen in HIV-1 infection by induction of CD4 and CD3 unresponsiveness.

HIV-1 envelope glycoprotein (gp120) may contribute to the magnitude of the immunological defects observed in the early stages of HIV-1 infection by modulating CD4 from the cell surface and altering the function of both CD4 and CD3 in uninfected cells. We investigated CD4 expression as well as CD3- and CD4-mediated cell migration in normal peripheral blood T lymphocytes exposed to recombinant gp120 in long-term cultures for < or = 6 days. Single low doses of gp120 (0.5 microgram/ml) modulated CD4 by 4-6 h, reached a nadir at 24-72 h, and began to recover at 96 h. By day 6, surface expression of CD4 had rebounded to control levels. CD3 expression was unchanged at all time points. Concomitant with loss of surface CD4 was significant lessening of both anti-CD4 and anti-CD3 antibody-induced migration. Reexpression of CD4 at 96 h resulted in the recovery of both CD4- and CD3-mediated migration. Cycloheximide inhibited CD4 reexpression and both anti-CD4 and anti-CD3 antibody-induced migration in cells treated with gp120. These data suggest that CD4 modulation by gp120 results in loss of function, which persists until new membrane CD4 is generated. Persistent exposure of CD4+ cells to gp120 in vivo may contribute to the disproportionately large immunological deficits seen in the early stages of HIV-1 infection, in which most CD4+ cells remain uninfected.

CD3 Complex↗
PubMed1992

Evidence for recent as well as long term activation of T cells migrating through endothelial cell monolayers in vitro.

As T cells actively extravasate from blood, they adhere to endothelium and then migrate out of the vessel with a locomotive activity. Although both adhesion and locomotion are properties associated with activated T cells, the two processes are not necessarily associated with identical activation states. Using human endothelial cells (EC) cultured to confluence on collagen gel, we examined the activation state of human peripheral blood T cells that adhere to and migrate through EC monolayers with three different methods: flow cytometric analysis of cell surface activation-related molecules, incorporation of tritiated nucleotide, and cell cycle analysis. The results were as follows. 1) Although expression of very late activation Ag integrins VLA-2 and VLA-3 by the initial blood T cell population (unseparated cells) and of adherent T cells was minimal, 40 to 45% of migrating cells were positive for VLA-2 and VLA-3. 2) The percentage of IL-2R+ cells in both unseparated and adherent cells was below 5% whereas the percentage of IL-2R+ cells among the migrating cells was 22 +/- 9% (range, 12 to 31%, n = 6). 3) Migrating cells expressed the highest CD26, whereas CD26 of adherent (nonmigrating) cells was divided into negative and high expression; in contrast, leukocyte adhesion molecule-1 (L-selectin) of both adherent and migrating cells was mostly low or negative. 4) [3H]Uridine incorporation of migrating and adherent cells was 2.1- to 2.5-fold and 1.4- to 1.7-fold higher, respectively, than that of unseparated cells, indicating that RNA synthesis of migrating cells as well as adherent cells was enhanced. 5) Cell cycle analysis showed that 23.5% of migrating cells appeared to enter the G1 phase but not S or G2 + M phases whereas 2.2% of unseparated cells and 8.0% of adherent cells that did not migrate had an RNA content consistent with entry into G1. These results suggest that cells migrating from normal human blood through unactivated EC have been activated recently as well as showing evidence of long term activation. The activation state of migrating cells is consistent with the hypothesis that previous in vivo activation is required for cells to migrate through EC in this system.

Animals↗
PubMed1992

Identification of HIV-1 envelope glycoprotein in the serum of AIDS and ARC patients.

Binding of the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein (gp120) has been reported to alter the function and surface antigen expression of lymphocytes and monocytes in vitro. To determine whether these in vitro findings could be relevant in vivo, we searched for the presence of this antigen in the serum of patients with AIDS and the AIDS-related complex (ARC). Using an antigen capture enzyme-linked immunosorbent assay (ELISA) with polyclonal anti-gp120 antibody, we detected envelope antigens (gp160/120) in serum of 22 of 32 AIDS patients. In contrast, an ELISA using solid-phase recombinant CD4 to capture gp160/120 failed to detect any positives. A modification of the anti-gp120-based ELISA identified gp160/120-IgG immune complexes in all of 11 AIDS patients tested and in 4 ARC patients who were negative for gp160/120 antigen. We conclude that gp160/120, predominantly in the form of immune complexes, can be identified as circulating antigen in patients with AIDS. The potential pathogenic consequences of this antigenemia, its relation to soluble CD4 therapy, and its application as a clinical marker of disease merit further study.

AIDS-Related Complex↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1990

Biologic activities of HIV-1 envelope glycoprotein: the effects of crosslinking.

We have examined the biologic activities of native and recombinant preparations of human immunodeficiency virus envelope glycoprotein (gp120), both derived from the HIV-1B strain. Antibody to gp120 was used to evaluate the effects of crosslinking gp120 on signalling by the CD4 receptor. Our results indicate that native and recombinant gp120 produce identical effects in our assay systems. Crosslinking gp120 amplified its chemoattractant activity for lymphocytes and monocytes and increased the peak intracellular calcium level, compared with binding of gp120 alone. The induction of inositol trisphosphate (IP3) production, induction of interleukin 2 receptors (IL2R), and inhibition of lymphocyte proliferation following treatment with gp120 were not enhanced by the addition of crosslinking antibody.

CD4-Positive T-Lymphocytes↗
PubMed1988

Lymphocyte activation by HIV-1 envelope glycoprotein.

Cell activation by phytohaemagglutinin, phorbol ester and by the supernatant of phytohaemagglutinin-stimulated peripheral blood mononuclear cells induces the expression and cytopathic effects of latent human immunodeficiency virus type-1 (HIV-1) in vitro. The lymphocyte surface protein CD4 has been identified as a receptor for HIV-1 and binds the viral envelope glycoprotein (gp120). In the light of evidence indicating that one natural function of CD4 is as a growth factor receptor, we examined the ability of native gp120 to activate resting CD4-bearing lymphocytes. Our results indicate that gp120 has innate biological activity as a result of a specific interaction with CD4, inducing increases in intracellular levels of inositol trisphosphate and of calcium, and in interleukin-2 receptor expression and cell motility.

Calcium↗
PubMed1987

Lymphokine activation of T4+ T lymphocytes and monocytes.

The function of the T4 antigen, a marker for a differentiated T cell subset, is not well understood. Our previous observation that a chemoattractant human lymphokine, lymphocyte chemoattractant factor (LCF), which selectively induces motile responses in unactivated T4+ lymphocytes, led us to investigate whether LCF could also induce T4+ cell activation. Because LCF acts selectively on T4+ cells, we next determined whether the T4 antigen has a function in this LCF-induced cellular activation. A T4+ lymphocyte migratory response is induced by divalent anti-T4 antibody, but not by corresponding Fab fragments of the same antibody. Fab fragments of anti-T4 antibody, but not Fab fragments of anti-T3 antibody, block the migratory effect of both LCF and divalent anti-T4. Furthermore, LCF but not divalent anti-T4, evokes the expression of interleukin 2 (IL 2) receptors and HLA-DR antigen on T4+ lymphocytes in 24 hr. These effects are quantitatively similar to those observed by anti-T3 antibody activation. LCF-induced IL 2 receptor expression is blocked by co-incubation with anti-T4 antibody and anti-T4 Fab fragments, whereas anti-T3 activation is not inhibitable by anti-T4 Fab fragments. Because cultured monocytes express the T4 antigen, we investigated the action of LCF on cultured monocyte migration and HLA-DR expression. Induction of monocyte migration by LCF and anti-T4 antibody increases proportionally as T4 antigen expression increases in vitro. This enhanced migration is inhibitable by anti-T4 Fab fragments. Monocyte activation, as measured by augmented HLA-DR expression 24 hr after incubation with LCF, but not anti-T4 antibody, is quantitatively similar to the effects of interferon-gamma. Augmented HLA-DR expression is blocked by anti-T4 Fab fragments but not by antibody to interferon-gamma. These studies indicate that LCF interacts with T4+ lymphocytes and monocytes to induce migration and cellular activation.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1986

A human T-T-cell hybridoma-derived lymphocyte chemoattractant factor.

Human T-T hybridomas were developed as a strategy for obtaining lymphokines that alter T-lymphocyte motility. Mitogen-stimulated human T lymphocytes were fused with cells of the human CEM lymphoma line and the supernatants derived from these fusion products were assessed for chemoattractant activity in a modified Boyden chamber assay. Supernatants from hybridoma 41B2 enhanced lymphocyte migration to 198 +/- 13% (mean +/- SEM) of control. Characterization by Sephadex G-100 molecular sieve chromatography revealed a single peak of chemoattractant activity corresponding to a molecular weight (MW) of 56,000. This activity eluted from a Sephadex QAE anion-exchange column at 4-6 mS. Subsequent isoelectric focusing in sucrose revealed an isoelectric point of 9.0-9.2. Fractions with activity after sequential molecular sieve and anion-exchange chromatography were concentrated, radiolabeled with 125I, and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography revealed a band which corresponded to a MW of 14,000 (representing four similar monomeric chains) and to the region from which chemoattractant activity could be detected in eluates from slices of unstained gels run in parallel. The biological activity of this hybridoma-derived lymphocyte chemoattractant was abolished by treatment with trypsin and neuraminidase but was unaffected by heating to 56 degrees C. We conclude that certain human T-T-cell hybridomas constitutively elaborate a lymphocyte chemoattractant that appears to be physicochemically identical to a previously described human lymphokine, lymphocyte chemoattractant factor.

Antigens, Differentiation, T-Lymphocyte↗