scholarly journals Tetraspanins CD9 and CD81 function to prevent the fusion of mononuclear phagocytes

2003 ◽  
Vol 161 (5) ◽  
pp. 945-956 ◽  
Author(s):  
Yoshito Takeda ◽  
Isao Tachibana ◽  
Kenji Miyado ◽  
Masatoshi Kobayashi ◽  
Toru Miyazaki ◽  
...  
Keyword(s):  
Complex Formation ◽  
Alveolar Macrophages ◽  
Bone Marrow Cells ◽  
Giant Cells ◽  
Mononuclear Phagocytes ◽  
Blood Monocytes ◽  
Multinucleated Cells ◽  
Infected Cells

Tetraspanins CD9 and CD81 facilitate the fusion between gametes, myoblasts, or virus-infected cells. Here, we investigated the role of these tetraspanins in the fusion of mononuclear phagocytes. Expression of CD9 and CD81 and their complex formation with integrins were up-regulated when blood monocytes were cultured under normal conditions. Under fusogenic conditions in the presence of Con A, CD9 and CD81 up-regulation was inhibited, and their complex formation with integrins was down-regulated. Anti-CD9 and -CD81 antibodies, which were previously shown to inhibit the fusion of gametes, myoblasts, and virus-infected cells, unexpectedly promoted the fusion of monocytes and alveolar macrophages. However, these effects were not due to altered cell adhesion, aggregation, or cytokine production. When stimulated in vitro or in vivo, alveolar macrophages and bone marrow cells of CD9- and CD81-null mice formed larger numbers of multinucleated cells than those of wild-type mice. Finally, CD9/CD81 double-null mice spontaneously developed multinucleated giant cells in the lung and showed enhanced osteoclastogenesis in the bone. These results suggest that CD9 and CD81 coordinately prevent the fusion of mononuclear phagocytes.

Multinucleated rat alveolar macrophages express functional receptors for calcitonin

1991 ◽  
Vol 261 (6) ◽  
pp. F1026-F1032 ◽  
Author(s):  
A. Vignery ◽  
M. J. Raymond ◽  
H. Y. Qian ◽  
F. Wang ◽  
S. A. Rosenzweig
Keyword(s):  
Plasma Membrane ◽  
Alveolar Macrophages ◽  
Giant Cells ◽  
Mononuclear Phagocytes ◽  
Inflammatory Reactions ◽  
Calcitonin Gene ◽  
Novel Model

The fusion of mononuclear phagocytes occurs spontaneously in vivo and leads to the differentiation of either multinucleated giant cells or osteoclasts in chronic inflammatory sites or in bone, respectively. Although osteoclasts are responsible for resorbing bone, the functional role of giant cells in chronic inflammatory reactions and tumors remains poorly understood. We recently reported that the plasma membrane of multinucleated macrophages is, like that of osteoclasts, enriched in Na-K-adenosinetriphosphatases (ATPases). We also observed that the localization of their Na-K-ATPases is restricted to the nonadherent domain of the plasma membrane of cells both in vivo and in vitro, thus imposing a functional polarity on their organization. By following this observation, we wished to investigate whether these cells also expressed, like osteoclasts, functional receptors for calcitonin (CT). To this end, alveolar macrophages were fused in vitro, and both their structural and functional association with CT was analyzed and compared with those of mononucleated peritoneal and alveolar macrophages. Evidence is presented that multinucleated alveolar macrophages express a high copy number of functional receptors for CT. Our results also indicate that alveolar macrophages, much like peritoneal, express functional receptors for calcitonin gene-related peptide. It is suggested that multinucleated rat alveolar macrophages offer a novel model system to study CT receptors and that calcitonin may control local immune reactions where giant cells differentiate.

scholarly journals Microglial mitogens are produced in the developing and injured mammalian brain.

1991 ◽  
Vol 112 (2) ◽  
pp. 323-333 ◽  
Author(s):  
D Giulian ◽  
B Johnson ◽  
J F Krebs ◽  
J K George ◽  
M Tapscott
Keyword(s):  
Cerebral Cortex ◽  
Growth Factors ◽  
Molecular Mass ◽  
Inflammatory Responses ◽  
Mononuclear Phagocytes ◽  
Mammalian Brain ◽  
Blood Monocytes ◽  
Adult Rats

The central nervous system produces growth factors that stimulate proliferation of ameboid microglia during embryogenesis and after traumatic injury. Two microglial mitogens (MMs) are recovered from the brain of newborn rat. MM1 has an approximate molecular mass of 50 kD and a pI of approximately 6.8; MM2 has a molecular mass of 22 kD and a pI of approximately 5.2. These trypsin-sensitive proteins show specificity of action upon glia in vitro serving as growth factors for ameboid microglia but not astroglia or oligodendroglia. Although the MMs did not stimulate proliferation of blood monocytes or resident peritoneal macrophage, MM1 shows granulocyte macrophage colony-stimulating activity when tested upon bone marrow progenitor cells. Microglial mitogens may help to control brain mononuclear phagocytes in vivo. The MMs first appear in the cerebral cortex of rat during early development with peak levels around embryonic day E-20, a period of microglial proliferation. Microglial mitogens are also produced by traumatized brain of adult rats within 2 d after injury. When infused into the cerebral cortex, MM1 and MM2 elicit large numbers of mononuclear phagocytes at the site of injection. In vitro study shows that astroglia from newborn brain secrete MM2. These observations point to the existence of a regulatory system whereby secretion of proteins from brain glia helps to control neighboring inflammatory responses.

C-C Chemokine receptor-like 2 (CCRL2) acts as coreceptor for human immunodeficiency virus-2

2020 ◽  
Author(s):  
Salequl Islam ◽  
Mohammad Ali Moni ◽  
Umme Laila Urmi ◽  
Atsushi Tanaka ◽  
Hiroo Hoshino
Keyword(s):  
Chemokine Receptors ◽  
Giant Cells ◽  
Immunofluorescence Assay ◽  
Glioma Cell Line ◽  
Proviral Dna ◽  
Hiv Entry ◽  
Infected Cells ◽  
Cluster Of Differentiation

Abstract Introduction Most of the typical chemokine receptors (CKRs) have been identified as coreceptors for a variety of human and simian immunodeficiency viruses (HIVs and SIVs). This study evaluated CCRL2 to examine if it was an HIV/SIV coreceptor. Methods The Human glioma cell line, NP-2, is normally resistant to infection by HIV and SIV. The cell was transduced with amplified cluster of differentiation 4 (CD4) as a receptor and CCR5, CXCR4 and CCRL2 as coreceptor candidates to produce NP-2/CD4/coreceptor cells (). The cells were infected with multiplicity of infection (MOI) 1.0. Infected cells were detected by indirect immunofluorescence assay (IFA). Multinucleated giant cells (MGC) in syncytia were quantified by Giemsa staining. Proviral DNA was detected by polymerase chain reaction (PCR), and reverse transcriptase (RT) activity was measured. Results IFA detected viral antigens of the primary isolates, HIV-1HAN2 and HIV-2MIR in infected NP-2/CD4/CCRL2 cells, indicated CCRL2 as a functional coreceptor. IFA results were confirmed by the detection of proviral DNA and measurement of RT-activity in the spent cell supernatants. Additionally, MGC was detected in HIV-2MIR-infected NP-2/CD4/CCCRL2 cells. HIV-2MIR were found more potent users of CCRL2 than HIV-1HAN2. Moreover, GWAS studies, gene ontology and cell signaling pathways of the HIV-associated genes show interaction of CCRL2 with HIV/SIV envelope protein. Conclusions In vitro experiments showed CCRL2 to function as a newly identified coreceptor for primary HIV-2 isolates conveniently. The findings contribute additional insights into HIV/SIV transmission and pathogenesis. However, its in vivo relevance still needs to be evaluated. Confirming in vivo relevance, ligands of CCRL2 can be investigated as potential targets for HIV entry-inhibitor drugs.

scholarly journals Porcine reproductive and respiratory syndrome virus-infected alveolar macrophages contain no detectable levels of viral proteins in their plasma membrane and are protected against antibody-dependent, complement-mediated cell lysis

2006 ◽  
Vol 87 (8) ◽  
pp. 2341-2351 ◽  
Author(s):  
Sarah Costers ◽  
Peter L. Delputte ◽  
Hans J. Nauwynck
Keyword(s):  
Plasma Membrane ◽  
Immune Evasion ◽  
Alveolar Macrophages ◽  
Viral Proteins ◽  
Cell Lysis ◽  
Respiratory Syndrome Virus ◽  
Specific Antibodies ◽  
Infected Cells

Porcine reproductive and respiratory syndrome virus (PRRSV) can evade the host immune system, which results in prolonged virus replication for several weeks to several months. To date, the mechanisms of PRRSV immune evasion have not been investigated in detail. One possible immune-evasion strategy is to avoid incorporation of viral proteins into the plasma membrane of infected cells, as this prevents recognition by virus-specific antibodies and consequent cell lysis either by the classical complement pathway or by antibody-dependent, cell-mediated cytotoxicity. In this study, viral proteins were not observed in the plasma membrane of in vitro-infected macrophages by using confocal microscopy or flow cytometry. Subsequently, the sensitivity of PRRSV-infected macrophages towards antibody-dependent, complement-mediated cell lysis (ADCML) was determined by using an ADCML assay. A non-significant percentage of PRRSV-infected cells were killed in the assay, showing that in vitro PRRSV-infected macrophages are protected against ADCML. PRRSV proteins were not detected in the plasma membrane of in vivo-infected alveolar macrophages and ADCML was also not observed. Together, these data indicate that viral proteins are not incorporated into the plasma membrane of PRRSV-infected macrophages, which makes infected cells invisible to PRRSV-specific antibodies. This absence of viral proteins on the cell surface could explain the protection against ADCML observed for in vitro and in vivo PRRSV-infected macrophages, and may play a role in virus persistence.

scholarly journals Identification of a subset of murine natural killer cells that mediates rejection of Hh-1d but not Hh-1b bone marrow grafts.

1989 ◽  
Vol 170 (1) ◽  
pp. 191-202 ◽  
Author(s):  
C L Sentman ◽  
J Hackett ◽  
V Kumar ◽  
M Bennett
Keyword(s):  
Bone Marrow ◽  
Natural Killer Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Tumor Cells ◽  
Bone Marrow Cells ◽  
Immune Functions ◽  
Infected Cells

NK cells demonstrate many immune functions both in vitro and in vivo, including the lysis of tumor or virus-infected cells and the rejection of bone marrow allografts. However it remains unclear whether or not all NK cells can mediate these various functions or if NK cells exist in functionally distinct subsets. We have developed a new NK-specific mAb, SW5E6, which binds to approximately 50% of murine NK cells. The 5E6 antigen identifies a distinct and stable subset of NK cells and is expressed on about one-half of fresh or rIL-2-activated murine NK cells. Both 5E6+ and 5E6- NK cells are capable of lysing YAC-1 tumor cells in vitro and in vivo. By treating animals with SW5E6, we demonstrate that the 5E6+ subset is necessary for the rejection of H-2d/Hh-1d but not H-2b/Hh-1b bone marrow cells. Thus NK cells exist as functionally separable subsets in vivo.

scholarly journals Polarized distribution of Na+,K+-ATPase in giant cells elicited in vivo and in vitro.

1989 ◽  
Vol 37 (8) ◽  
pp. 1265-1271 ◽  
Author(s):  
A Vignery ◽  
T Niven-Fairchild ◽  
D H Ingbar ◽  
M Caplan
Keyword(s):  
Plasma Membrane ◽  
Giant Cell ◽  
Giant Cells ◽  
Suitable Model ◽  
Inflammatory Reactions ◽  
Morphological Alterations ◽  
Multinucleated Cells ◽  
High Level

Giant cell formation was analyzed to determine whether it results in the high level of Na+,K+-ATPase expression that characterizes multinucleated cells such as osteoclasts. Giant cells and fusing alveolar macrophages were subjected to morphological, immunological, and biochemical studies. Both subunits of the Na+,K+-ATPase were found to be present on the plasma membrane of giant cells. Their localization was restricted to the non-adherent domain of the cell surface. Dynamic studies of giant cell differentiation demonstrated that on culture and/or multinucleation, an increase in sodium pump alpha-subunit synthesis occurred and led to a high level of expression of Na pumps. Conversely, the adherent plasma membrane of giant cells was enriched in a lysosomal membrane antigen. This study demonstrates that culture and/or multinucleation induces a significant increase in the expression of sodium pumps. The polarized distribution of these pumps and of a lysosomal component suggests that fusing macrophages undergo biochemical and morphological alterations which prepare them for a new and specialized function in chronic inflammatory reactions. Giant cells may offer a suitable model system to study the differentiation of other related multinucleated cells, such as osteoclasts.

scholarly journals Characteristics of human mononuclear phagocytes

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 485-500 ◽  
Author(s):  
R van Furth ◽  
JA Raeburn ◽  
TL van Zwet
Keyword(s):  
Bone Marrow ◽  
Peripheral Blood ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocyte ◽  
Mononuclear Phagocytes ◽  
Blood Monocytes ◽  
Surface Receptors ◽  
Three Body

Abstract In this study human mononuclear phagocytes from the bone marrow (promonocytes and monocytes), peripheral blood monocytes, and tissue macrophages from the skin and the peritoneal cavity were studied with respect to their morphological, cytochemical, and functional characteristics, cell surface receptors, and 3H-thymidine incorporation in vitro. The results show similarities between mononuclear phagocytes of the three body compartments with respect to esterase staining, the presence of peroxidase-positive granules, the presence of IgG and C receptors, and pinocytic and phagocytic activity. Promonocytes are the most immature mononuclear phagocytes identified in human bone marrow, and since about 80% of these cells incorporate 3H-thymidine, they are actively dividing cells. Monocytes, whether in bone marrow or the peripheral blood, and both skin and peritoneal macrophages label minimally with 3H-thymidine and thus are nondividing cells. Since the characteristics of mononuclear phagocytes in man and mouse do not diverge greatly, it is probable that the cell sequence based on in vitro and in vivo 3H-thymidine labeling studies in the mouse holds for man as well. The successive stages of development of the human mononuclear phagocyte cell line will then be as follows: monoblasts (not yet characterized in man) divide to form promonocytes, and these cells in turn divide and give rise to monocytes that do not divide further; they leave the bone marrow, circulate in the peripheral blood, and finally become macrophages in the various tissues.

scholarly journals THE KINETICS OF PROMONOCYTES AND MONOCYTES IN THE BONE MARROW

1970 ◽  
Vol 132 (4) ◽  
pp. 813-828 ◽  
Author(s):  
Ralph van Furth ◽  
Martina M. C. Diesselhoff-den Dulk
Keyword(s):  
Bone Marrow ◽  
Cell Types ◽  
Mononuclear Phagocytes ◽  
Blood Monocytes ◽  
Proliferating Cells ◽  
Synthesis Time ◽  
In Vivo Labeling ◽  
The Mean

The mononuclear phagocytes of the bone marrow can be classified into two cell types, promonocytes and monocytes. The present study was performed to establish whether the promonocytes are the progenitors of the monocytes and to determine the kinetic characteristics of the promonocytes and monocytes in the bone marrow compartment. Both in vitro labeling studies with thymidine-3H and determination of the relative amount of DNA in the nuclei of individual cells showed that under normal steady-state conditions the promonocytes are proliferating cells and the monocytes, nondividing cells. In vivo labeling studies provided further evidence that the promonocytes are the progenitor cells of the monocytes. During the first 24 hr after labeling, the promonocytes showed a constant high level of labeling (about 70%). The mean grain count of these cells decreased with time. The labeling index of the monocytes of the bone marrow increased during the first 24 hr after in vivo labeling, but during the same period the mean grain counts remained almost constant, with values amounting to about half those of the promonocytes during the first 6 hr of the experiment. The data concerning the labeling indices and the percentage distribution ratio of the promonocytes and monocytes in the bone marrow, and the labeling indices of the peripheral blood monocytes are used to construct a model population. The results lead to the conclusions that the promonocytes are multiplicative cells and that both daughter cells arising from the division of a promonocyte are monocytes. The DNA-synthesis time found for the promonocytes is 13.6 hr. From this value, the average generation time was computed to be 19.5 hr.

Human alveolar macrophages: effects of endotoxin in vitro

1980 ◽  
Vol 30 (3) ◽  
pp. 753-758
Author(s):  
W B Davis ◽  
I S Barsoum ◽  
P W Ramwell ◽  
H Yeager
Keyword(s):  
Alveolar Macrophages ◽  
Fiberoptic Bronchoscopy ◽  
Significant Inhibition ◽  
Mononuclear Phagocytes ◽  
Human Alveolar Macrophages ◽  
In Vitro Effects ◽  
Gram Negative Organisms ◽  
And Function

Experiments were performed to evaluate the in vitro effects of Escherichia coli lipopolysaccharide on viability and function of human alveolar macrophages. Alveolar macrophages were obtained by fiberoptic bronchoscopy and saline bronchial lavage from 12 normal, nonsmoking volunteers. Cells were incubated with different concentrations of E. coli endotoxin for 1 and 24 h. Endotoxin (10 microgram/ml and more) was cytotoxic for alveolar macrophages after 24 h of incubation and induced significant inhibition of phagocytosis, adherence, and spreading. The effects of endotoxin on alveolar macrophage viability and function were dose and time dependent and were not influenced by indomethacin. Thus, human alveolar macrophages, like other mononuclear phagocytes, are extremely sensitive to endotoxin effects; these observations may be relevant in conditions in which endotoxin may be in contact with alveolar macrophages in vivo: endobronchial infections with gram-negative organisms, byssinosis, chronic bronchitis of grain handles, and humidifier fever.

scholarly journals Characteristics of human mononuclear phagocytes

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 485-500 ◽  
Author(s):  
R van Furth ◽  
JA Raeburn ◽  
TL van Zwet
Keyword(s):  
Bone Marrow ◽  
Peripheral Blood ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocyte ◽  
Mononuclear Phagocytes ◽  
Blood Monocytes ◽  
Surface Receptors ◽  
Three Body

In this study human mononuclear phagocytes from the bone marrow (promonocytes and monocytes), peripheral blood monocytes, and tissue macrophages from the skin and the peritoneal cavity were studied with respect to their morphological, cytochemical, and functional characteristics, cell surface receptors, and 3H-thymidine incorporation in vitro. The results show similarities between mononuclear phagocytes of the three body compartments with respect to esterase staining, the presence of peroxidase-positive granules, the presence of IgG and C receptors, and pinocytic and phagocytic activity. Promonocytes are the most immature mononuclear phagocytes identified in human bone marrow, and since about 80% of these cells incorporate 3H-thymidine, they are actively dividing cells. Monocytes, whether in bone marrow or the peripheral blood, and both skin and peritoneal macrophages label minimally with 3H-thymidine and thus are nondividing cells. Since the characteristics of mononuclear phagocytes in man and mouse do not diverge greatly, it is probable that the cell sequence based on in vitro and in vivo 3H-thymidine labeling studies in the mouse holds for man as well. The successive stages of development of the human mononuclear phagocyte cell line will then be as follows: monoblasts (not yet characterized in man) divide to form promonocytes, and these cells in turn divide and give rise to monocytes that do not divide further; they leave the bone marrow, circulate in the peripheral blood, and finally become macrophages in the various tissues.

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