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PubMed1981

The role of monocytes in pokeweed mitogen-stimulated human B cell activation: separate requirements for intact monocytes and a soluble monocyte factor.

Mononuclear phagocytes (M phi) play an essential role in mitogen-induced proliferation and generation of immunoglobulin-secreting cells (ISC) from human peripheral blood lymphocytes. The nature of this accessory function was examined using the pokeweed mitogen (PWM) model of lymphocyte activation. M phi-depleted human peripheral blood lymphocytes are unresponsive to PWM. Fresh, intact M phi, but not heat-killed M phi, reconstitute the capacity of these cells both to proliferate and generate ISC in response to PWM. In the presence of intact M phi, soluble M phi factors augment PWM-induced generation of ISC but do not enhance 3H-thymidine incorporation. In the absence of intact M phi, the M phi supernatants are unable to support either response. Secretion of active M phi supernatants was completed within the first 24 to 48 hr of incubation, with little additional factor secreted thereafter. Aged M phi, which no longer secreted active factors, fully reconstituted the proliferative response of M phi-depleted lymphocytes; however, they were unable to support PWM-triggered differentiation of B cells into ISC. The addition of active M phi supernatants to the aged M phi restored their capacity to support PWM-triggered generation of ISC. Highly purified Interleukin 1 was also able to enhance the accessory cell function of both fresh and aged M phi in a similar manner. These results suggest that IL-1 is the M phi factor required for the differentiation of human B cells into ISC. Moreover, the data indicate that in the human, M phi accessory cell function involves 2 separate modalities. Both intact M phi and a factor released by fresh M phi (Interleukin 1) are required to support differentiation of B cells into ISC, while only intact M phi are necessary for PWM-induced lymphocyte proliferation.

Aging↗
PubMed1989

Isolation of monocyte-depleted and monocyte-rich fractions from human mononuclear cells.

Utilizing a recently reported characteristic of monocytes to aggregate in cold, a new procedure for obtaining monocyte-rich and monocyte-depleted mononuclear fractions from human blood is described. After aggregation in cold and adherence to plastic, a fraction containing 88% monocyte (LeuM3 CD14+) is obtained. After treating the supernatant, which separates from the aggregates, with a monocyte lysosomotropic agent (L-Leucine Methyl Ester), a fraction containing 0% monocyte (LeuM3 CD14+) and 88% lymphocytes (Leu4 CD3+ and Leu 12 CD19+) is obtained. In round-bottom culture wells, this monocyte-depleted fraction produced immunoglobulins in response to pokeweed mitogen (5,826 +/- 2,356 IgM micrograms/ml), to a degree not significantly different that that produced in the presence of monocytes (7,426 +/- 3,347 IgM micrograms/ml). This suggests the presence of cells in the lymphocyte fraction, that are not monocytes but are capable of antigen presenting.

Adult↗
PubMed1987

Comparison of recombinant tumor necrosis factor and the monocyte-derived cytotoxic factor involved in monocyte-mediated cytotoxicity.

A direct comparison of recombinant tumor necrosis factor (rTNF) and the monocyte-derived cytotoxic factor (CF) which is involved in monocyte-mediated cytotoxicity revealed immunological, physiochemical, and biological similarities, indicating that TNF is an effector molecule in monocyte-mediated cytotoxicity. Neutralizing antiserum raised against rTNF completely inhibited the ability of CF-containing monocyte supernatants to induce cytolysis and cell death of sensitive target cells and, conversely, antiserum raised against purified CF completely inhibited the cytotoxic activity of rTNF. Both CF and rTNF have an apparent isoelectric point of 5.8-5.9 as determined by chromatofocusing, and a molecular weight of about 40,000 as determined by gel filtration. Moreover, when present in monocyte supernatants with a total protein concentration of about 1 mg/ml and 0.1% sodium dodecyl sulfate, both CF and rTNF migrated with a molecular weight of about 35,000 upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Pure rTNF, however, migrated with a molecular weight of 17,000, suggesting that the relative amount of sodium dodecyl sulfate to protein is critical for dissociating the apparent dimeric structure of TNF. CF and rTNF were also similar with respect to their ability to kill various types of target cells the sensitivity of which to TNF differ, and the dose-response curves of cytotoxicity obtained with CF-containing monocyte supernatants and rTNF were similar. As is the case with anti-CF serum, anti-rTNF serum inhibited drug-dependent cellular cytotoxicity and cytolysis mediated by both freshly isolated monocytes and in vitro cultured unactivated and lymphokine-lipopolysaccharide activated monocytes, indicating that TNF is an effector molecule in both drug-dependent cellular cytotoxicity and "classical" monocyte-mediated cytotoxicity.

Animals↗
PubMed1995

Monocyte chemotactic protein-3 (MCP3) interacts with multiple leukocyte receptors: binding and signaling of MCP3 through shared as well as unique receptors on monocytes and neutrophils.

The diversity of monocyte chemotactic protein (MCP)3 target cell types, as well as the capacity of MCP3 to desensitize leukocyte responses to other CC chemokines, suggested that MCP3 may interact with multiple CC chemokine receptors. The purpose of this study is to establish how MCP3 binds and activates monocytes and neutrophils. We show that human monocytes exhibit high-affinity binding for 125I-MCP3 with an estimated Kd of 1-3 nM and about 10,000 binding sites/cell. The binding of 125I-MCP3 to monocytes was progressively less well competed by CC chemokines macrophage inflammatory protein (MIP)1 alpha (Kd = 5-10 nM), RANTES (Kd = 5-10 nM), MCP1 (monocyte chemoattractant and activating factor, or MCAF) (Kd = 60 nM) and MIP1 beta (Kd > 100 nM). On the other hand, unlabeled MCP3 displaced the binding of radiolabeled MIP1 alpha, RANTES, MCP1 and MIP1 beta as effectively as the isologous CC chemokines. In agreement with the binding data, pretreatment of monocytes with MCP3 completely desensitized the calcium flux in response to MIP1 alpha and RANTES. However, MIP1 alpha and RANTES failed to desensitize the response of monocytes to MCP3. MCP3 and MCP1 partially desensitized each other's effects on monocytes. These binding and cross-desensitization results suggest that MCP3 binds and signals through other binding sites in addition to those shared with MIP1 alpha, RANTES and MCP1. The unidirectional competition for MIP1 beta binding and signaling by MCP3 suggests the existence of an as-yet unidentified site for MCP3 shared with MIP1 beta. The existence of another unique binding site(s) for MCP3 was further shown by the failure of any of the other CC chemokines to compete effectively for MCP3 binding on neutrophils. MCP3 in our study was also the only human CC chemokine that consistently chemoattracted neutrophils. These results suggest that MCP3 is a ligand that can bind and activate a broad range of target cells through receptors shared by other CC chemokines as well as its own receptor.

Calcium↗
PubMed1996

Activation of human monocytes and the acute monocytic leukemia cell line (THP-1) by lipoxins involves unique signaling pathways for lipoxin A4 versus lipoxin B4: evidence for differential Ca2+ mobilization.

Lipoxins are bioactive eicosanoids that are generated during multicellular events such as inflammation, thrombosis, and atherosclerosis. They have selective actions on peripheral blood cells, in that previous results indicate that lipoxin A4 (LXA4) and lipoxin B4 (LXB4) inhibit neutrophil migration while they are both potent stimuli of peripheral blood monocyte (PBM) chemotaxis and adherence. Here, we report the impact of lipoxins on levels of free cytosolic calcium ([Ca2+]i) in PBM and THP-1 cells (acute monocytic leukemia cells) as well as on the functional responses of these cells. LXA4, but not LXB4, induced a concentration-dependent increase in [Ca2+]i in monocytes that was half-maximal at approximately 200 nM. Prior exposure of the cells to EGTA reduced the LXA4-induced increase in [Ca2+]i by approximately 50 to 60%, indicating the contribution of both intracellular mobilization and external influx in LXA4 Ca2+ regulation. A leukotriene B4 receptor antagonist, ONO 4057, did not significantly alter LXA4-induced [Ca2+]i, while it inhibited the action of leukotriene B4. LXA4 also induced a rise in [Ca2+]i in the monocytic leukemia cell line (time to reach maximum = 15.1 +/- 0.87 s), and both LXA4 and LXB4 stimulated a concentration-dependent THP-1 cell adherence to laminin with concentrations as low as 10(-10)M. In contrast to the findings with LXA4, exposure of THP-1 or PBM to LXB4 was not accompanied by mobilization of intracellular Ca2+. Although both LXA4 and LXB4 stimulate adherence of PBM, they did not evoke superoxide anion generation by these cells, nor did they affect the rate of acidification of extracellular medium by monocytes, as monitored using a microphysiometer. Together, these results indicate that an increase in [Ca2+]i is a component of the signal transduction events following monocyte interaction with LXA4, but not LXB4, and that both LXA4 and LXB4 are potent and selective agonists for THP-1 cells and PBM. Moreover, they suggest that LX display a unique profile of actions with mononuclear cells compared with other known agonists of monocytes, and that LX can direct monocyte-mediated events.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Rat monocytes up-regulate NKR-P1A and down-modulate CD4 and CD43 during activation in vivo: monocyte subpopulations in normal and IFN-gamma-treated rats.

LEW rats were treated intravenously with recombinant rat interferon-gamma (IFN-gamma) for 3 days to achieve intravascular accumulation, proliferation, and activation of monocytes. Monocytes, defined by their expression of the ED1, ED9, and Ox41 antigens, were recovered from the vasculature by perfusion with PBS/EDTA, subsequently depleted of erythrocytes and granulocytes by Percoll density gradient centrifugation, and analyzed by flow cytometry and immunocytology. In untreated and control-infused specified pathogen-free (SPF) rats, lymphocytes and monocytes formed overlapping cell populations with respect to size and internal granularity. At least two intravascular monocyte subsets, probably central and marginating cells, were distinguished by their size and differential expression of CD43, CD4, CD11a, CD18, and L-selectin. It is interesting to note that a fraction of the monocytes in normal and control-infused animals carried the NKR-P1A molecule. IFN-gamma treatment provoked a duplication of monocyte size and granularity. Both the number of positive monocytes and the level of expression of NKR-P1A strongly increased after IFN-gamma infusion, whereas CD43 (leukosialin) and CD4 were impressively down-regulated. NKR-P1A+ L-selectin+ CD43low CD4- monocytes also occur in the vasculature of rats during immune reactions in vivo. We speculate that these cells are involved in organ damage and that their number is controlled by activation-induced cell death within the vessels.

Animals↗
PubMed1995

Human monocytes produce monocyte chemoattractant protein 1 (MCP-1) in response to a synthetic peptide derived from C-reactive protein.

We reported previously that a synthetic peptide (RS-83277) derived from human C-reactive protein (CRP) augmented human monocyte/macrophage tumoricidal activity and cytokine production. RS-83287, a synthetic peptide derived from a different CRP site, was ineffective. Because chemoattractant properties have been attributed to some CRP-derived peptides, we hypothesized that RS-83277, in addition to activating effects, might promote human monocyte chemotaxis. Results indicated that neither CRP peptide RS-83277 nor RS-83287 was, itself, a chemoattractant. RS-83277, but not RS-83287, however, elicited time-dependent production of monocyte chemoattractant activity in conditioned media (CM) of cultured human mononuclear leukocytes and purified, adherent monocytes (MO). CM from nonadherent MO contained no activity, indicating that adherence was required for monocyte response. Monocyte chemoattractant activity was dose-dependent and was removed by treatment with immobilized antibody to human monocyte chemoattractant protein 1 (MCP-1) but not by irrelevant IgG. These results indicate that a specific peptide segment of CRP acts upon human adherent monocytes to promote production of the autocrine chemotactic and activating factor MCP-1. Data suggest that degraded CRP represents a complex source of biologically active peptides which, among other effects, may amplify monocyte recruitment to sites of injury.

C-Reactive Protein↗
PubMed1985

Defective monocyte function in acquired immune deficiency syndrome (AIDS): evidence from a monocyte-dependent T-cell proliferative system.

T-cell proliferative responses to the mitogenic monoclonal antibody anti-Leu 4 were assessed in healthy controls, lymphadenopathy syndrome (LAS) patients, and acquired immune deficiency syndrome (AIDS) patients. While 19% of the control group showed low anti-Leu 4 responses (less than 12,000 cpm), 60% of the LAS patients, 71% of the AIDS-opportunistic infection patients, and 50% of the AIDS-Kaposi's sarcoma patients showed low responses. T-cell responsiveness in healthy low responders was greatly enhanced by the addition of monocytes from an anti-Leu 4 high responder (responder monocytes). We therefore sought to determine if the low-responder state in LAS and AIDS patients was also mediated by monocytes and, thus, correctable by the addition of responder monocytes. In the LAS low-responder group, the level of enhancement by healthy responder monocytes was similar to that observed for the healthy low-responder group. In the AIDS low-responder group, however, the level of enhancement was significantly lower than that observed in the healthy low-responder and LAS low-responder groups. These findings suggest that impaired proliferation to anti-Leu 4 in LAS patients may be due to a monocyte defect similar to the monocyte defect responsible for low anti-Leu 4 responses in healthy controls. AIDS patients, however, show additional defects in anti-Leu 4-induced proliferation that are not fully corrected by the addition of responder monocytes.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Expression of monocyte chemoattractant protein-1 in monocytes and effects of native and oxidized very low density lipoproteins.

Monocyte chemoattractant protein-1 (MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL (OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37 degrees C, and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.

Arteriosclerosis↗
PubMed1987

Surface receptors and immune activity of purified human circulating mononuclear cells. III. The mechanisms of lysis, by lymphocytes and monocytes, of target cells in the lymphocyte-dependent and monocyte-dependent ADCC, NK, NOCC, and MICC cytotoxic reactions.

The abilities of unfractionated mononuclear cells (MNC), monocytes (98-99% pure), and lymphocytes (98-99% pure) to carry out the lysis of target cells in the ADCC, NK, NOCC, and MICC assays were compared. Lymphocytes by themselves were able to lyse the CRBC (ADCC), K-562 (NK), and RRBC (MICC) target cells. The monocytes were very effective in the lysis of the CRBC (MICC) target cells. However, the lysis of two other target cells--RRBC (NOCC) and HRBC (ADCC)--required the simultaneous presence of both lymphocytes and monocytes in order to effect optimal lysis. Soluble factor(s) secreted by the cytotoxic cells capable of lysing the target cells were detected only in the NK assay. The activity of the soluble cytotoxic factor (NKCF) was only 25-40% of that exhibited by the cytotoxic NK cells and it was secreted by the cytotoxic cells after 48 hr of culture and not 24 hr of culture which is the usual assay condition. The NKCF was cytotoxic only to the NK target cells and not to the target cells used in the ADCC, NOCC, and MICC cytotoxic assays. Different classes of lymphocytes were cytotoxic in the monocyte-independent assays [ADCC (CRBC), NK (K-562), and MICC (RRBC)]. The null lymphocytes and the T lymphocytes were the primary cytotoxic cells in the ADCC and MICC assays, respectively, whereas the T, B, and null cells were almost equally cytotoxic in the NK assay. With respect to the monocyte-dependent assays [ADCC (HRBC), NOCC (RRBC), and MICC (CRBC)], the cytotoxic activity of any one class of lymphocytes failed to approach that of the unfractionated MNC. The T cells were the most cytotoxic; the B cells exhibited limited cytotoxic activity in only the ADCC assay and the null cells showed no cytotoxic activity. However, the combination of T and non-T cells and, to a lesser extent, T and B cells, exhibited much greater cytotoxic activity than the individual cells and together were as cytotoxic as the unfractionated MNC. It is concluded that, depending upon the selection of the target cells, lysis in the ADCC, NK, NOCC, and MICC assays may be effected by lymphocytes only, by monocytes only, by both monocytes and lymphocytes, or as a result of lymphocyte-monocyte collaboration. In the latter instance more than one class of lymphocytes must be present in order for maximum cytotoxic activity to be expressed.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1990

Cell surface antigens and function of monocytes and a monocyte-like cell line before and after infection with HIV.

The human immunodeficiency virus (HIV-1) preferentially infects cells that express the CD4 molecule, including monocytes and cells of the monocyte lineage. The monocyte-like cell line U937 and monocytes isolated from peripheral blood lymphocytes (PBL) were infected with HIV-1. Cell surface antigen expression was determined in infected and noninfected cells as was the ability to stimulate in mixed lymphocyte reaction. The CD4 antigen decreased in infected cells U937 and PBL monocytes. MHC class II antigens HLA-DR, HLA-DQ, and HLA-DP increased in HIV-1 infected U937 cells. In infected PBL-derived monocytes, HLA-DR increased, HLA-DQ decreased, and HLA-DP was unchanged. Infected U937 and PBL monocytes were capable of stimulating allogeneic lymphocytes, thus demonstrating retention of the alloantigen presentation function of HIV-1-infected monocytes.

Antigens, Surface↗
PubMed1995

Modulation of monocyte antigen-presenting capacity by tumour necrosis factor-alpha (TNF): opposing effects of exogenous TNF before and after an antigen pulse and the role of TNF gene activation in monocytes.

We have previously shown that exogenous human recombinant tumour necrosis factor-alpha (rTNF), added before an antigen pulse, enhanced antigen presentation by human blood monocytes. The present study shows that, surprisingly, rTNF added after an antigen (PPD) pulse inhibited, while anti-TNF monoclonal antibody (mAb) enhanced, antigen presentation. mAbs htr-9 against p55 TNF receptor type I (TNF-RI) abrogated rTNF enhancing effect on PPD presentation and decreased presenting activity of untreated monocytes while utr-1 mAb, against p75 TNF receptor type II (TNF-RII), reversed the inhibitory effect of rTNF given after antigen pulse. PPD and rTNF when added singly induced TNF-mRNA accumulation in monocytes. Pretreatment of monocytes with rTNF followed by a PPD pulse caused an enhancement of TNF-mRNA accumulation. However, when post-treatment with rTNF was applied to PPD-pulsed monocytes, then inhibition of TNF gene expression was seen. This may point to the role of endogenously generated TNF in regulation of antigen-presenting capacity of monocytes. These studies indicate that TNF is an important regulator of monocyte antigen-presenting capacity and that the level of TNF gene activation in monocytes may be associated with their ability to present nominal antigen.

Antibodies, Monoclonal↗
PubMed1993

Phagocytosis of Mycobacterium tuberculosis or particulate stimuli by human monocytic cells induces equivalent monocyte chemotactic protein-1 gene expression.

Phagocytosis of Mycobacterium tuberculosis by human monocytes or macrophages is classically followed by granuloma formation in vivo. Granuloma are comprised of cells of the monocyte lineage together, in many instances, with antigen-specific T lymphocytes. Development of granuloma depends upon recruitment of both cell types, but recruitment of monocytes is pivotal as these cells secrete anti-mycobacterial cytokines and IL-8, a T cell chemoattractant. We have therefore investigated gene regulation of Monocyte Chemotactic Protein 1 (MCP-1), an important monocyte chemotactic cytokine, following phagocytosis of particulate material (latex beads and zymosan) and live M. tuberculosis by two human monocytic cell lines. In THP-1 cells and phenotypically more differentiated Mono Mac 6 cells, MCP-1 mRNA accumulation was first detectable by Northern analysis of 4 hours and increased over 24 hours. Magnitude and kinetics of MCP-1 gene expression was independent of the biochemical nature of the phagocytic stimulus, M. tuberculosis strain virulence or pre-treatment with anti-TNF. In contrast to the uniform effect of different phagocytic stimuli on MCP-1 gene expression, we have shown that M. tuberculosis but not latex or zymosan, increased IL-8 gene expression, a chemotactic agent for T cells. In additional experiments with THP-1 cells infected with human immunodeficiency virus (HIV), viral infection did not alter MCP-1 gene expression following phagocytosis. MCP-1 gene expression appears to be a conserved antigen-independent response of human monocytic cells which is activated following particulate phagocytosis. MCP-1 gene expression may thus be involved in recruitment of monocytes during granuloma formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Line↗
PubMed2005

Secretion of monocyte chemotactic protein-1 by human uterine epithelium directs monocyte migration in culture.

OBJECTIVE: To determine whether primary human uterine epithelial cells in culture are able to influence monocyte chemotaxis and to establish whether the causal agent of chemotaxis is monocyte chemotactic protein (MCP)-1. DESIGN: Tissue culture study. SETTING: University medical center. PATIENT(S): Women aged 23 to 53 years who were undergoing hysterectomy (n=7). INTERVENTION(S): Primary human endometrial epithelial cells were acquired from surgical specimens and grown to confluence and high transepithelial resistance. Conditioned media from epithelial cultures were analyzed for the presence of MCP-1 and for capacity to affect monocyte chemotaxis using the THP-1 monocyte line. Antibody neutralization of conditioned media was used to establish the role of MCP-1 in chemotaxis. MAIN OUTCOME MEASURE(S): Assay of conditioned media for MCP-1, quantitative measurement of monocyte chemotaxis to conditioned media, and inhibition of chemotaxis by antibody neutralization of MCP-1. RESULT(S): Primary endometrial epithelial cells in monolayer culture secrete MCP-1 to both the apical and basolateral compartments. Monocyte chemotactic protein-1 was identified as the primary agent of monocyte chemotaxis by antibody neutralization. CONCLUSION(S): These findings suggest that biologically active MCP-1 is secreted into both the uterine lumen as well as the underlying stroma and that it mediates the presence of monocytes, macrophages, and other immune cells in the uterine endometrium.

Adult↗
PubMed2003

Monocyte chemoattractant protein-1 induces scavenger receptor expression and monocyte differentiation into foam cells.

Accumulation of monocytes and the entrapment of oxidized-low-density lipoprotein (ox-LDL) in monocytes are important in the differentiation into "foam" macrophages and the pathogenesis of atherosclerosis. We investigated the role of monocyte chemoattractant protein-1 (MCP-1) in the expression of scavenger receptor (SCR) by using resting monocytes prepared by counterflow centrifugal elutriation. Our results showed that: (1) MCP-1 increased the expression of CD36 SCR by flow cytometric analysis. (2) MCP-1 increased incorporation of 125I-labeled ox-LDL and oil red O staining. (3) MCP-1 and ox-LDL enhanced in vitro transendothelial monocyte migration. (4) These functions were mediated at least in part via extracellular signal-regulated kinase (ERK) pathway. (5) MCP-1 and ox-LDL did not induce monocyte proliferation. Our results imply that MCP-1 is involved in the inflammatory process of atherosclerosis through the induction of SCR expression via the ERK pathway and differentiation of monocytes into foam macrophages, as well as induction of monocyte migration.

CD36 Antigens↗
PubMed1987

Monocyte cytolytic factor in promoting monocyte-mediated lysis of bladder cancer cells by bacillus Calmette-Guerin.

The role of monocytes in cell-mediated cytolysis of bladder cancer cells was investigated. Human peripheral monocytes released a cytolytic factor which lysed T24 bladder cancer cells and a number of human tumor cells, but not normal lymphocytes or fibroblasts. After incubation of monocytes with bacillus Calmette-Guerin for 48 hr. in vitro, cytolysis of T24 cells was increased up to 56.7 +/- 4.1%. Treatment of monocytes with actinomycin D (an inhibitor of RNA transcription) reduced release of cytolytic factor from 27.3 +/- 5.7% cytolysis to 4.5 +/- 1.4% (p less than 0.05). The response to mitomycin C was different between lymphokines and monocyte cytolytic factor. The mouse monoclonal antibody against human recombinant tumor necrosis factor did not neutralize monocyte cytolytic factor. These results show that this monocyte cytolytic factor is distinct from lymphokines and tumor necrosis factor. The evidence that bacillus Calmette-Guerin increases release of monocyte cytolytic factor may be associated with anti-tumor activity of bacillus Calmette-Guerin in intravesical therapy for treatment of bladder cancer.

Cell Line↗
PubMed1997

Phenotype of porcine monocytic cells: modulation of surface molecule expression upon monocyte differentiation into macrophages.

When porcine blood monocytes differentiate in vitro into macrophages, their morphology, as well as side scatter and forward scatter measured by flow cytometry, changed in a manner similar to that with human cells. During this differentiation, the initial high expression of CD molecules on porcine monocytes was down-regulated, with one exception--SWC9. Freshly isolated blood monocytes were SWC9-, but after culture the cells had become SWC9+. Thus, porcine monocytes were characterised as SWC3+SWC9-CD14high; macrophages were SWC3+SWC9+CD14low, the latter also displaying a down-regulation of CD11a/18, and, to a lesser degree, CD44. Both SWC9-CD14high monocytes and SWC9+CD14low macrophages were identifiable in freshly prepared monocytic cells from the spleen. Alveolar macrophages, on the other hand, were dominated by SWC9+CD14low cells, similar in phenotype to in vitro monocyte-derived macrophages. The consequences which these results have for studies on virus infections of porcine monocytic cells are discussed.

Animals↗
PubMed1996

Detection of CD 14 on migrated monocytes by specific antibody: a possible quantification for blood monocyte chemotaxis.

In the present study we investigated the possibility to use antigen-antibody recognition for detection of monocyte chemotaxis in the 48-well microchamber assay. The described method is based on recognition of cell-specific antigenic determinants present on the migrated monocytes. After conventional 48-well chemotaxis, the migrated cells were incubated with an antibody against the monocyte surface marker CD14 (3C10 hybridoma). Subsequent incubation with enzyme-coupled antibodies and their substrate allowed the antigen and hence the migrated cells carrying this antigen, to be detected and measured in a microplate reader. Our results show that chemotaxis of normal blood monocytes towards the monocyte chemoattractants FMLP and MCP-1 could be detected with the anti-CD14 antibody 3C10 in combination with a horse-radish peroxidase coupled antibody, and that the optical density is a measure for cell number per well (positive correlation, r = 0.95). Incubation of monocytes with the applied chemoattractants FMLP and MCP-1 did not change the CD14 expression as was determined by FACScan analysis. Therefore we conclude that it is possible to use antibodies directed against antigenic determinants like CD14 to detect blood monocyte migration in a more objective way compared to subjective counting of cells on a filter. Eventually, this method can be valuable, especially for chemokine research since chemokines exert their effects on specific target cell populations. By varying the detection antibody, other cell populations besides monocytes may be quantified.

Antibodies, Monoclonal↗