Characterization of Monocyte-Associated Factor V

SummaryWe demonstrate that in addition to possessing binding sites for intact factor V (FV), unstimulated peripheral blood monocytes also express activated factor V (FVa) on their surfaces. FVa was identified on the monocyte surface by monoclonal antibody B38 recognizing FVa light chain and by human oligoclonal antibodies H1 (to FVa light chain) and H2 (to FVa heavy chain) using immunofluorescence microscopy and flow cytometry. On Western blots, partially cleaved FV could be identified as a 220 kDa band in lysates of monocytes. In addition to surface expression of FVa, monocytes also contain intracellular FV as detected only after permeabilization by Triton X-100 by monoclonal antibody B10 directed specifically to the Cl domain not present in FVa. We sought to determine whether the presence of FV in peripheral blood monocytes is a result of de novo synthesis.Using in situ hybridization, no FV mRNA could be detected in monocytes, while in parallel control studies, factor V mRNA was detectable in Hep G2 cells and CD18 mRNA in monocytes. In addition, using reverse transcriptase and the polymerase chain reaction, no FV mRNA was detected in mononuclear cells or in U937 cells, but mRNA for factor V was present in Hep G2 cells using the same techniques. These data suggest that FV is present in human monocytes, presumably acquired by binding of plasma FV, and that the presence of this critical coagulation factor is not due to de novo synthesis.

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Evidence for specific annexin I-binding proteins on human monocytes

Biochemical Journal ◽

10.1042/bj3160593 ◽

1996 ◽

Vol 316 (2) ◽

pp. 593-597 ◽

Cited By ~ 38

Author(s):

Nicolas J. GOULDING ◽

L PAN ◽

Kathleen WARDWELL ◽

Veronica C. GUYRE ◽

Paul M. GUYRE

Keyword(s):

Monoclonal Antibody ◽

Peripheral Blood ◽

Binding Proteins ◽

Human Peripheral Blood ◽

Flow Cytometric Analysis ◽

Blood Monocytes ◽

Surface Binding ◽

Peripheral Blood Monocytes ◽

Cell Functions ◽

Annexin I

Recombinant human annexin I and a monoclonal antibody specific for this protein (mAb 1B) were used to investigate surface binding of this member of the annexin family of proteins to peripheral blood monocytes. Flow cytometric analysis demonstrated trypsin-sensitive, saturable binding of annexin I to human peripheral blood monocytes but not to admixed lymphocytes. A monoclonal antibody that blocks the anti-phospholipase activity of annexin I also blocked its binding to monocytes. These findings suggest the presence of specific binding sites on monocytes. Furthermore, surface iodination, immunoprecipitation and SDS/PAGE analysis were used to identify two annexin I-binding proteins on the surface of monocytes with molecular masses of 15 kDa and 18 kDa respectively. The identification and characterization of these annexin I-binding molecules should help us to better understand the specific interactions of annexin I with monocytes that lead to down-regulation of pro-inflammatory cell functions.

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A murine monoclonal antibody strictly reactive with human peripheral blood monocytes

Clinical Immunology and Immunopathology ◽

10.1016/0090-1229(87)90084-5 ◽

1987 ◽

Vol 45 (3) ◽

pp. 310-322 ◽

Cited By ~ 1

Author(s):

Margherita Cuomo ◽

Luciana Santoro ◽

Marcella Mottolese ◽

Raffaele Tecce ◽

Vittorio Rosato ◽

...

Keyword(s):

Monoclonal Antibody ◽

Peripheral Blood ◽

Human Peripheral Blood ◽

Murine Monoclonal Antibody ◽

Blood Monocytes ◽

Peripheral Blood Monocytes

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Enhanced Adhesion of Pasteurella multocida to Cultured Turkey Peripheral Blood Monocytes

Infection and Immunity ◽

10.1128/iai.67.3.1292-1296.1999 ◽

1999 ◽

Vol 67 (3) ◽

pp. 1292-1296 ◽

Cited By ~ 17

Author(s):

Ingrid M. Pruimboom ◽

Richard B. Rimler ◽

Mark R. Ackermann

Keyword(s):

Monoclonal Antibody ◽

Hyaluronic Acid ◽

Peripheral Blood ◽

Pasteurella Multocida ◽

Collagen Iv ◽

Blood Monocytes ◽

Myristate Acetate ◽

Peripheral Blood Monocytes ◽

Cell Surface Proteoglycan ◽

Binding Cell

ABSTRACT Capsular hyaluronic acid (HA) mediates adhesion of serogroup A strains of Pasteurella multocida to elicited turkey air sac macrophages (TASM). In contrast, freshly isolated turkey peripheral blood monocytes (TPBM) do not bind serogroup A strains. Following culture of TPBM for 6 days in chamber slides, adhesion of the bacteria to TPBM increased gradually. Incubation in chamber slides coated with entactin-collagen IV-laminin (ECL) attachment matrix or exposure to phorbol myristate acetate (PMA) further enhanced the adhesion ofP. multocida to TPBM. Addition of HA, but not Arg-Gly-Asp peptide, to TPBM culture inhibited bacterial adherence similarly to the inhibition previously reported for TASM. Exposure of TPBM to monoclonal antibody directed against HA-binding cell surface proteoglycan (CD44) decreased binding of P. multocida. Collectively, these findings indicate that P. multocida adhesion to TPBM is mediated by capsular HA and can be increased by culture on ECL attachment matrix or PMA exposure. Additionally, the findings suggest that the capsular mucopolysaccharide of serogroup A strains of P. multocida recognizes an isoform of CD44 expressed on cultured TPBM.

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Lack of involvement of lipocortin 1 in dexamethasone suppression of IL-1 release

Mediators of Inflammation ◽

10.1155/s0962935193000067 ◽

1993 ◽

Vol 2 (1) ◽

pp. 49-52 ◽

Cited By ~ 3

Author(s):

E. F. Morand ◽

D. Rickard ◽

N. J. Goulding

Keyword(s):

Monoclonal Antibody ◽

Peripheral Blood ◽

Interleukin 1Β ◽

Blood Monocytes ◽

Peripheral Blood Monocytes ◽

Neutralizing Monoclonal Antibody ◽

Anti Inflammatory ◽

Dexamethasone Suppression

The annexin lipocortin 1 is reported to mediate some anti-inflammatory effects of glucocorticoids, but the mechanisms of this mediation are incompletely understood. The involvement of lipocortin 1 in glucocorticoid inhibition of monocyte interleukin 1β (IL-1β) release has been investigated. Treatment of peripheral blood monocytes with 2 μg/ml lipopolysaccharide potently increased IL–1β release (p = 0.001) and dexamethasone (10−7M) significantly reduced both resting and stimulated IL-1β release (p = 0.009). A neutralizing monoclonal antibody to lipocortin 1 (0.5–50.0 μg/ml) was unable to inhibit this effect and recombinant lipocortin 1 (2 × 10−6M) and 188aa lipocortin 1 fragment (10−8−10−6M) had no effect. It is concluded that lipocortin 1 is not involved in the inhibition of monocyte IL-1β release by glucocorticoids.

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