Monocyte Subsets in Neonates and Children

PEDIATRICS ◽  
1979 ◽  
Vol 64 (5) ◽  
pp. 740-743
Author(s):  
Edward B. Arenson ◽  
Martin B. Epstein ◽  
Robert C. Seeger

Volumetrically distinct subpopulations of peripheral blood monocytes, termed M1, M2, and M3, were identified in healthy normal adults and children. Because normal neonates have abnormal monocyte chemotaxis, it was determined whether monocyte subpopulations have different chemotactic capabilities and, if so, whether chemotactically active subpopulations were quantitatively deficient in neonates. Chemotaxis tests with zymosan-activated normal human serum as the chemoattractant and purified monocyte subpopulations revealed that large M3 monocytes were capable of significantly more directed migration than were small M1 and M2 monocytes. Volumetric analysis of monocytes from normal newborns rather than demonstrating an absence of M3 cells revealed that these cells were the predominant monocyte subpopulation. Therefore, we conclude that the impaired chemotactic ability of newborn monocytes is due to a functional rather than quantitative deficiency of M3 cells.

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 579-582
Author(s):  
LJ Weisberg ◽  
DT Shiu ◽  
PR Conkling ◽  
MA Shuman

Factor XIII is the fibrin-stabilizing factor that covalently cross- links fibrin monomers to form a highly organized, stable fibrin clot. The plasma form of factor XIII is a heterodimer, a2b2, consisting of two a-chains and two b-chains; the intracellular form, such as in platelets and placenta, is a dimer, a2, consisting of a-chains only. The catalytic function of factor XIII, a transglutaminase, resides in the a-chain. To address questions regarding sites of synthesis of factor XIII a-chain, an EcoRI restriction fragment from the protein- coding region of the factor XIII a-chain cDNA was used as a probe for Northern blot analysis. The cDNA probe showed hybridization with a single approximately 4.0-kilobase (kb) message in poly (A)+ mRNA prepared from normal human peripheral blood monocytes and normal human liver. The results demonstrate conclusively that factor XIII a-chains are actively synthesized in circulating monocytes and in liver. To our knowledge, these data represent the first demonstration of synthesis of any blood coagulation factor in primary uncultured and unstimulated monocytes or macrophage cells.


1985 ◽  
Vol 249 (1) ◽  
pp. E94-E98
Author(s):  
R. H. Whitson ◽  
S. A. Kaplan

When normal human peripheral blood monocytes were treated with insulin in vitro, surface insulin receptors disappeared rapidly, but total insulin receptors (surface and internalized receptors), measured in detergent-solubilized extracts of total cellular membranes, decreased slowly. Surface receptors decreased to 51 +/- 4, 36 +/- 12, and 34 +/- 12%, of control levels after 2, 6, and 18 h of insulin pretreatment, respectively. Total receptors decreased to 86 +/- 12, 69 +/- 17, and 34 +/- 12% of control levels in the same periods. Chloroquine, a lysosomotropic agent, inhibited the removal of surface receptors, indicating that lysosomal proteases play a role in this process. Unlike monocytes, IM-9 lymphocytes lost surface receptors and total receptors at the same rate when incubated with insulin. Monocytes treated with insulin for 18 h, washed free of unbound insulin and recultured for 48 h regained 94 +/- 7% of control insulin binding, indicating that cultured monocytes are competent to regenerate their insulin receptors. Monocytes treated with insulin for 6 h also required 48 h to recover their insulin binding, despite the fact that substantial numbers of insulin receptors remained intact within these cells. Two-hour pretreated monocytes recovered somewhat faster, attaining control levels of receptors after 24 h of reculture. This suggests that internalized insulin receptors pass from a recyclable pool to a nonrecyclable one.


1986 ◽  
Vol 164 (6) ◽  
pp. 2095-2100 ◽  
Author(s):  
T S Kupper ◽  
D W Ballard ◽  
A O Chua ◽  
J S McGuire ◽  
P M Flood ◽  
...  

Keratinocytes produce an IL-1 like factor termed epidermal cell-derived thymocyte-activating factor (ETAF). In this study, we show that ETAF and IL-1 are identical by the following criteria: Both normal and malignant human keratinocytes contain mRNAs identical to monocytic IL-1 alpha and IL-1 beta mRNA, as determined by an S1 nuclease protection assay; and IL-1 activity in medium conditioned by these cells can be neutralized by antibodies specific for human IL-1. The IL-1 alpha and IL-1 beta mRNAs can be identified in cultured human keratinocytes in the absence of identifiable stimulation; this basal level of mRNA can be further induced to accumulate with certain defined stimuli. Cultured normal human keratinocytes (HFKs) contain 2-4 times more IL-1 alpha than IL-1 beta mRNA; in contrast, human peripheral blood monocytes contain 10-20 times more IL-1 beta than IL-1 alpha mRNA. The IL-1 activity released by these HFK can be neutralized by an antibody that neutralizes both alpha and beta IL-1, but not by an antibody that neutralizes only IL-1 beta. While human monocytes produce a large excess of IL-1 beta after appropriate stimulation, these data suggest that IL-1 alpha is a major (and may be the predominant) form of IL-1 produced by human keratinocytes.


2005 ◽  
Vol 95 (1) ◽  
pp. 139-148 ◽  
Author(s):  
David W. Dempster ◽  
Christine E. Hughes-Begos ◽  
Katarina Plavetic-Chee ◽  
Andrea Brandao-Burch ◽  
Felicia Cosman ◽  
...  

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 579-582 ◽  
Author(s):  
LJ Weisberg ◽  
DT Shiu ◽  
PR Conkling ◽  
MA Shuman

Abstract Factor XIII is the fibrin-stabilizing factor that covalently cross- links fibrin monomers to form a highly organized, stable fibrin clot. The plasma form of factor XIII is a heterodimer, a2b2, consisting of two a-chains and two b-chains; the intracellular form, such as in platelets and placenta, is a dimer, a2, consisting of a-chains only. The catalytic function of factor XIII, a transglutaminase, resides in the a-chain. To address questions regarding sites of synthesis of factor XIII a-chain, an EcoRI restriction fragment from the protein- coding region of the factor XIII a-chain cDNA was used as a probe for Northern blot analysis. The cDNA probe showed hybridization with a single approximately 4.0-kilobase (kb) message in poly (A)+ mRNA prepared from normal human peripheral blood monocytes and normal human liver. The results demonstrate conclusively that factor XIII a-chains are actively synthesized in circulating monocytes and in liver. To our knowledge, these data represent the first demonstration of synthesis of any blood coagulation factor in primary uncultured and unstimulated monocytes or macrophage cells.


1995 ◽  
Vol 268 (4) ◽  
pp. F746-F753 ◽  
Author(s):  
M. Gallieni ◽  
S. Kamimura ◽  
A. Ahmed ◽  
E. Bravo ◽  
J. Delmez ◽  
...  

In chronic uremia, the requirement of supraphysiological doses of serum 25-hydroxyvitamin D3 [25(OH)D3] for the normalization of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] levels has been attributed to impaired substrate availability to renal 1 alpha-hydroxylase. Because serum 1,25(OH)2D3 can also be corrected by 25(OH)D3 supplementation in bilaterally nephrectomized patients, we examined the role of substrate availability on 1,25(OH)2D3 production by peripheral blood monocytes (PBM). In hemodialysis patients (HP), 25(OH)D3 uptake was 50% lower than normal, and the maximal velocity (Vmax) and apparent Michaelis constant (Km) for 25(OH)D3 of 1 alpha-hydroxylase were 2.7- and 4-fold above normal, respectively. When serum 1,25(OH)2D3 of HP was corrected by intravenous 1,25(OH)2D3, 25(OH)D3 uptake, Km, and Vmax returned to normal values. The effect of 25(OH)D3 supplementation was also examined. In normal adults, 25(OH)D3 administration had no effect on serum 1,25(OH)2D3 levels nor on the Km or the Vmax of PBM 1 alpha-hydroxylase but caused a 11-fold increase in serum 24R,25-dihydroxyvitamin D3[24R, 25(OH)2D3]. In HP, 25(OH)D3 therapy raised serum 1,25(OH)2D3 and reduced the Km and Vmax of PBM 1 alpha-hydroxylase, which correlated negatively with serum 1,25(OH)2D3. However, serum 24R,25(OH)2D3 only increased slightly above basal. These results demonstrate that, in HP, 1) impaired uptake of 25(OH)D3 and low affinity for substrate determine the need for high 25(OH)D3 levels to normalize serum 1,25(OH)2D3, despite higher enzymatic activity; 2) 1,25(OH)2D3 deficiency plays a role in enhanced 1,25(OH)2D3 synthesis and impaired access of 25(OH)D3 to PBM 1 alpha hydroxylase; and 3) abnormal 25(OH)D3 delivery also affects 24-hydroxylation.


1993 ◽  
Vol 70 (02) ◽  
pp. 273-280 ◽  
Author(s):  
Janos Kappelmayer ◽  
Satya P Kunapuli ◽  
Edward G Wyshock ◽  
Robert W Colman

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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