Human Peripheral Blood Adherent Cells Research Articles

Cellular, Molecular, and Immunological Characteristics of Langhans Multinucleated Giant Cells Programmed by IL-15

Langhans multinucleated giant cells (LGCs) are a specific type of multinucleated giant cell containing a characteristic horseshoe-shaped ring of nuclei that are present within granulomas of infectious etiology. Although cytokines that trigger macrophage activation (such as IFN-γ) induce LGC formation, it is not clear whether cytokines that trigger macrophage differentiation contribute to LGC formation. Here, we found that IL-15, a cytokine that induces M1 macrophage differentiation, programs human peripheral blood adherent cells to form LGCs. Analysis of the IL-15‒treated adherent cell transcriptome identified gene networks for T cells, DNA damage and replication, and IFN-inducible genes that correlated with IL-15 treatment and LGC-type multinucleated giant cell formation. Gene networks enriched for myeloid cells were anticorrelated with IL-15 treatment and LGC formation. Functional studies revealed that T cells were required for IL-15‒induced LGC formation, involving a direct contact with myeloid cells through CD40L-CD40 interaction and IFN-γ release. These data indicate that IL-15 induces LGC formation through the direct interaction of activated T cells and myeloid cells.

Immature dendritic cells possess a sugar-sensitive receptor for human mannan-binding lectin.

Mannan-binding lectin (MBL) is a collectin synthesized by the liver and secreted into the bloodstream. It has a receptor for microbial structures in its C-type lectin domain and a separate receptor(s) located within its collagen-like region for autologous phagocytic cells. Here we demonstrate that human peripheral blood adherent cells (monocytes) and monocyte-derived dendritic cells are a source of MBL, and that a novel calcium-dependent and sugar-specific MBL receptor is up-regulated in immature (CD1a-positive) dendritic cells. These findings suggest a previously unsuspected autologous function for MBL, perhaps a regulatory role within the immune system.

Molecular Cloning of the cDNA and Chromosomal Localization of the Gene for a Putative Seven-Transmembrane Segment (7-TMS) Receptor Isolated from Human Spleen

A family of proinflammatory cytokines sharing several structural features has been described and includes, for example, interleukin-8, monocyte chemoattractant protein-1, and melanocyte growth stimulatory activity. Recently, the receptors for interleukin-8 have been isolated and found to belong to the seven-transmembrane domain class of G protein-coupled receptors. As other members of this cytokine family likely interact with similar receptors, the polymerase chain reaction was employed to isolate related receptors from human peripheral blood adherent cells. Degenerate oligonucleotide primers based on the rabbit interleukin-8 receptor sequence were used. The corresponding full-length cDNA was isolated from a human spleen cDNA library. The predicted protein sequence of this clone, designated pBE1.3, was 93% identical to that of a cDNA isolated from bovine locus coeruleus, which apparently encodes a neuropeptide Y receptor, and also shows similarity with the interleukin-8 receptor and the human cytomegalovirus US28 sequences. The gene, designated D2S201E was localized to human chromosome 2q21. By Northern blotting, transcripts hybridizing to this cDNA were present in a variety of tissues and cells, including those of hemopoietic origin.

Inhibition by delta-9-tetrahydrocannabinol of tumor necrosis factor alpha production by mouse and human macrophages

Suppression by delta-9-tetrahydrocannabinol (THC) of tumor necrosis factor (TNF) production by macrophages has not been reported previously. The present study evaluated the effect in vitro of THC on soluble TNF-α production by cultured murine peritoneal macrophages. THC at 5 or 10 μg/ml added to medium [RPMI 1640 containing 10 ng LPS/ml, mouse IFN-γ (100 u/ml), and 0.5% bovine serum albumin (BSA)] used to induce TNF significantly decreased TNF-α production by BALB/c mouse macrophages. Macrophages pretreated with THC at 0.1, 0.5, or 1.0 μg/ml in protein-free medium for 3 h at 37°C, prior to TNF induction, also showed a decreased ability to produce TNF-α in a dose-dependent manner. Increasing the protein concentration from 0.5 to 5% BSA in the medium which was used to induce TNF prevented the inhibitory activity of THC. Human peripheral blood adherent cells treated with THC-containing medium produced less TNF-α than controls that were not exposed to THC. Thus, our data provide evidence that THC can inhibit TNF production by mouse and human macrophages. The drug's activity is concentration dependent and is related to the amount of serum protein in the medium used to induce this cytokine.

The influence of oestrone on the production of tumour necrosis factor by human peripheral blood adherent cells

Human peripheral blood adherent cells (PBAC) incubated with oestrone in high concentration (10(-5) M) release, on exposure to bacterial endotoxin, an amount of tumour necrosis factor (TNF) greater than do cells incubated without the steroid. The finding may imply a non-endocrine hormonal process leading to heightened local TNF responses. This may be the basis of endotoxin hypersensitivity in pregnancy.

The influence of oestrone on the production of tumour necrosis factor by human peripheral blood adherent cells

The influence of oestrone on the production of tumour necrosis factor by human peripheral blood adherent cells

Homotypic cell aggregation induced by anti-CD44(Pgp-1) monoclonal antibodies and related to CD44(Pgp-1) expression.

The present study shows that a mAb (H4C4) developed against human peripheral blood adherent cells has the unusual property of inducing in vitro homotypic aggregation of several types of hemopoietic cells and cell lines. The Ag recognized by mAb H4C4 is a 85-kDa glycoprotein that corresponds to the human Ag CD44 (equivalent to murine Pgp-1), as determined by protein purification, immunologic cross-reactivity studies, and tryptic fragment sequencing. In addition to H4C4, other mAb directed against some, but not all, epitopes of CD44(Pgp-1) were capable of inducing cell aggregation. This process was temperature sensitive and was almost totally abrogated by cytochalasin B but was unaffected by sodium azide, colchicine, EGTA, trifluoperazine, or staurosporin. A role for CD44 (Pgp-1) in cell-to-cell adhesion was further indicated by an inverse relationship observed between spontaneous aggregation of some hemopoietic cell lines and cell-surface expression of CD44(Pgp-1). These observations provide evidence for a fundamental role of CD44(Pgp-1) in cellular aggregation phenomena with an involvement of the cytoskeleton.

Evidence for shared antigenic determinants on rabbit and human interleukin 1 (IL 1).

An antiserum to human interleukin 1 (IL 1) was prepared by immunizing a goat with the isoelectric point (pI) 6.9 type of IL 1 in Freund's complete adjuvant. Serum-mediated inhibition of the biological activity of IL 1 appeared within 4 wk after the first immunization, and showed a progressive rise in titer over a 9-mo period. The inhibitory moiety was purified by sequential ammonium sulfate fractionation and DEAE-Sephacel ion exchange chromatography, and the activity was found to co-purify with the IgG fraction of the serum. The antibody neutralized the biological activity of the pI 6.9 type of human IL 1 derived from either human placental tissue or human peripheral blood adherent cells, but did not neutralize the pI 5.2 type of IL 1 derived from either source. When used as an affinity reagent, the antibody selectively absorbed the pI 6.9 human IL 1, but not the pI 5.2 human IL 1. Furthermore, the antibody neutralized the pI 7.4 type of IL 1 derived from rabbit alveolar macrophages, but had no activity against the pI 4.6 IL 1 derived from the same source. No inhibitory activity against rat spleen cell-derived IL 1 or murine P388D1 cell line-derived IL 1 was detected. These experiments support the concept that the differing pI types of IL 1 derived from the same species are both biochemically and antigenically distinct molecules, and IL 1 of similar pI type derived from different species may share antigenic determinants.

Adherent cell inhibition of human leukemic in vitro agar clonal growth by short-term cell-to-cell contact

The effects of peripheral blood adherent cells from normal donors on human myeloid leukemic cluster growth in agar were studied. A prior co- incubation of nonadherent leukemic cells with adherent cell monolayers from 9 out of 10 donors in liquid cultures over a 4-hr period was sufficient to reduce subsequent leukemic growth in semisolid agar cultures. Inhibition was seen with adherent to leukemic cell ratios of as low as 0.5:1. Conversely, identical numbers of adherent cells in agar cultures but separated from the leukemic cells enhanced growth more than the cultures containing human placental conditioned media alone. Because leukemic cell exposure to adherent cells was brief, a cytotoxic mechanism appeared likely; however, this could not be detected by 51Cr release. Human peripheral blood adherent cells not activated by any in vitro mechanism suppress clonal growth of human myeloid leukemic cells by a mechanism requiring cell to cell contact. Examination of the inhibition of clonal growth appears to be more sensitive than 51Cr release as an indicator of adherent cell effects on myeloid leukemia.

Adherent Cell Inhibition of Human Leukemic In Vitro Agar Clonal Growth by Short-Term Cell-to-Cell Contact

The effects of peripheral blood adherent cells from normal donors on human myeloid leukemic cluster growth in agar were studied. A prior co-incubation of nonadherent leukemic cells with adherent cell monolayers from 9 out of 10 donors in liquid cultures over a 4-hr period was sufficient to reduce subsequent leukemic growth in semisolid agar cultures. Inhibition was seen with adherent to leukemic cell ratios of as low as 0.5:1. Conversely, identical numbers of adherent cells in agar cultures but separated from the leukemic cells enhanced growth more than the cultures containing human placental conditioned media alone. Because leukemic cell exposure to adherent cells was brief, a cytotoxic mechanism appeared likely; however, this could not be detected by 61 Cr release. Human peripheral blood adherent cells not activated by any in vitro mechanism suppress clonal growth of human myeloid leukemic cells by a mechanism requiring cell to cell contact. Examination of the inhibition of clonal growth appears to be more sensitive than 51 Cr release as an indicator of adherent cell effects on myeloid leukemia.

Lymphocyte-Potentiating Factor from Human Peripheral Blood Adherent Cells

Low-molecular-weight factor, which can restore the diminished concanavalin A (Con A) response of adherent-cell-depleted human peripheral blood lymphocytes, was partially purified from the culture supernatant of human peripheral blood adherent cells by ion-exchange column chromatography, gel filtration and preparative paper chromatography. This factor apparently has a mechanism of action distinct from that of 2-mercaptoethanol. It affects the cells just before the onset of DNA synthesis possibly as one of the second signals in the Con-A-induced activation of human peripheral blood lymphocytes. However, it was demonstrated that the effective activation of lymphoyctes also required the presentation of Con A by adherent cells to lymphocytes at the triggering stage of the activation, indicating that adherent cells have two distinct functions in the Con-A-induced activation of lymphocytes, i.e. the the presentation of Con A to lymphoyctes and the elaboration of soluble factors.