Monocytes and cells of the dendritic cell lineage circulate in blood and eventually migrate into tissue where they further mature and serve various functions, most notably in immune defense. Over ...recent years these cells have been characterized in detail with the use of cell surface markers and flow cytometry, and subpopulations have been described. The present document proposes a nomenclature for these cells and defines 3 types of monocytes (classical, intermediate, and nonclassical monocytes) and 3 types of dendritic cells (plasmacytoid and 2 types of myeloid dendritic cells) in human and in mouse blood. This classification has been approved by the Nomenclature Committee of the International Union of Immunological Societies, and we are convinced that it will facilitate communication among experts and in the wider scientific community.
Background
The phenotypic heterogeneity of circulating tumor cells (CTC) in peripheral blood and disseminated tumor cells (DTC) in bone marrow is an important constraint for clinical decision making. ...Here, we investigated the implications of two different subpopulations of these cells in gastric cancer (GC).
Methods
GC patients (
n
= 228) who underwent elective gastric resections were prospectively examined for CTC/DTC. The cells obtained from peripheral blood and bone marrow aspirates were sorted by flow cytometry and CD45
−
cells expressing cytokeratins (8, 18, and 19) and CD44 were identified by immunofluorescent double staining.
Results
Ninety-three (41%) patients had cytokeratin-positive tumor cells in either blood or bone marrow, while cells expressing CD44 were found in 22 (10%) cases. CK
+
CD44
+
cells were significantly more common among patients with distant metastases (50 vs 19%,
P
= 0.001), while no such correlations were demonstrated for CK
+
CD44
−
cells. Detection of CK
+
CD44
+
cells, but not CK
+
CD44
−
, was associated with significantly shortened survival. Moreover, the Cox proportional hazards model identified CK
+
CD44
+
cells as a negative prognostic factor with an odds ratio of 2.38 (95% CI 1.28–4.41,
P
= 0.006).
Conclusion
CD44
+
phenotype of cytokeratin-positive cells in blood and bone marrow is an independent prognostic factor in patients with gastric cancer.
Abstract We have studied the effect of intravenous immunoglobulins (IVIG) on monocyte subpopulations and cytokine production in patients with CVID. The absolute number of CD14+ CD16++ monocytes ...decreased on average 2.5-fold 4 h after IVIG and after 20 h returned to the baseline. The cytokine level in the supernatants of peripheral blood mononuclear cells (PBMC) after ex vivo LPS stimulation demonstrated the > 2-fold decrease in TNF production 4 h after IVIG. The TNF expression, which is higher in the CD14+ CD16++ monocytes, was decreased in these cells by IVIG in 4/7 CVID cases. In vitro exposure of the healthy individuals' monocytes to the IVIG preparation resulted in reduced TNF production, which was overcome by blockade of the FcγRIIB in the CD14+ CD16++ CD32Bhigh monocytes. Our data suggest that reduction in the number of CD14+ CD16++ monocytes and the blockade of their cytokine production via triggering CD32B can contribute to the anti-inflammatory action of IVIG.
To determine whether monocytes can be generated from CD34+ hematopoietic progenitors in large numbers, cord blood CD34+ cells were first expanded for 3-10 days in X-VIVO 10 medium supplemented with ...FCS, stem cell factor (SCF), thrombopoietin (TPO), and Flt-3 Ligand (Flt-3L), and then differentiated in IMDM medium supplemented with FCS, SCF, Flt-3L, IL-3 and M-CSF for 7-14 days. These two step cultures resulted in up to a 600-fold mean increase of total CD14+ cells. Using this approach, two subpopulations of monocytes were obtained: CD14+CD16(-) and CD14++CD16+ occurring at 2:1 ratio. 1.25(OH)2 Vitamin D3 added to the differentiation medium altered this ratio by decreasing proportion of CD14++CD16+ monocytes. In comparison to CD14+CD16(-), the CD14++CD16+ cells showed different morphology and an enhanced expression of CD11b, CD33, CD40, CD64, CD86, CD163, HLA-DR, and CCR5. Both subpopulations secreted TNF and IL-12p40 but little or no IL-10. CD14++CD16+ monocytes released significantly more IL-12p40, were better stimulators of MLR but showed less S. aureus phagocytosis. These subpopulations are clearly different from those present in the blood and may be novel monocyte subsets that represent different stages in monocyte differentiation with distinct biological function.
There have been many discrepant observations on the serum levels of cytokines in cancer patients and their prognostic value. The purpose of this study was to determine the plasma levels of pro- and ...anti-inflammatory cytokines and their clinical significance in a large group of patients with gastric carcinoma. The levels of tumour necrosis factor alpha (TNF alpha), interleukin-12p40 (IL-12p40), IL-12p70, IL-18, IL-10 and soluble TNF receptors I and II sTNF-Rs were investigated in the plasma of 136 consecutive patients with biopsy proven gastric cancer using specific enzyme-linked immunoabsorbent assays (ELISA). Survival curves were estimated using the method of Kaplan and Meier and the differences in the survival rates were tested by the log-rank test. For multivariate analysis of prognostic factors, the Cox proportional hazard model was used. Proinflammatory cytokines and sTNF-Rs were higher in the whole group of patients in comparison to healthy volunteers. IL-10 was elevated mostly in advanced disease. The increased levels of IL-10 (>10 pg/ml) were associated with significantly poorer survival of patients, while the levels of the other cytokines and sTNF-Rs showed no correlation with prognosis. The increased level of IL-10 is an independent unfavorable prognostic factor in patients with gastric cancer.
The assessment of intracellular cytokines at the single-cell level by flow cytometry has recently become a potent tool in many areas of cell biology and in defining the role of cytokines in various ...human diseases. Three-color flow cytometry for detection of intracellular cytokines combined with simultaneous determination of lymphocytes (CD3(+) and CD4(+)) or monocytes (CD33(+) and CD14(+)) was used for comparison of phytohemagglutinin (PHA)-and phorbol myristate acetate (PMA)-ionomycin-induced production of intracellular cytokines in peripheral blood mononuclear cells (PBMCs) of healthy donors. We found that the number of PBMCs stained for tumor necrosis factor alpha and gamma interferon after 6 h of activation was higher when PMA-ionomycin was used for stimulation, while the frequencies of cells positive for interleukin 4 (IL-4) were similar for both stimulators. However, PMA-ionomycin stimulation caused prominent alterations of cell morphology and membrane expression of CD4 and CD14. In contrast, PHA did not cause downregulation of surface markers and resulted in less pronounced alterations in both forward and side scatter signals during flow cytometry analysis. Moreover, during 48 h of culture PHA stimulated tumor necrosis factor beta and IL-10 production, which was not observed when PMA-ionomycin was used. We conclude that the use of PHA for cell activation may limit in vitro artifacts and allow more precise analysis of intracellular cytokine production in various disease states.
Although blood monocytes exhibit significant cytotoxic activity against tumor cells, the function of tumor infiltrating macrophages (TIM) is depressed in cancer patients. This study addresses the ...question of how the antitumor response of human monocytes, assessed by production of cytokines (tumor necrosis factor alpha, TNF; IL-10; IL-12p40) and cytotoxicity, is altered by exposure to cancer cells. Tumor cell--pre-exposed monocytes restimulated with tumor cells showed significantly decreased production of TNF, IL-12, increased IL-10 (mRNA and release) and inhibition of IL-1 receptor-associated kinase-1 (IRAK-1) expression. This down-regulation of cytokine production was selective, as the response of pre-exposed monocytes to lipopolysaccharide (LPS) was unaffected. Treatment of tumor cell--pre-exposed monocytes with hyaluronidase (HAase) improved their depressed production of TNF, while HAase-treated cancer cells did not cause monocyte dysfunction. The response of hyaluronan (HA)--pre-exposed monocytes to stimulation with tumor cells was also inhibited. Cytotoxic activity of monocytes pretreated with cancer cells was also decreased. This study shows that tumor cells selectively deactivate monocytes and suggests that tumor cell-derived HA by blocking CD44 on monocytes inhibits their antitumor response. These observations may provide some explanation for the depressed function of TIM in human malignancy.
In an attempt to elaborate in vitro on a therapeutic strategy that counteracts an inflammatory signal, we previously reported a novel immunopharmacological potential of glutathione, an antioxidant ...thiol, in regulating inflammatory cytokines. In the present study, we investigated the hypothesis that selective regulation of phosphodiesterases (PDEs), a family of enzymes that controls intracellular cAMP/cGMP degradation, differentially regulates proinflammatory cytokines. Selective PDE1 inhibition (8-methoxymethyl-3-isobutyl-1-methylxanthine) blockaded lipopolysaccharide-endotoxin (LPS)-mediated biosynthesis of interleukin (IL)-6, but this pathway had no inhibitory effect on tumor necrosis factor-alpha (TNF-alpha). Furthermore, inhibition of PDE3 (amrinone) abolished the effect of LPS on IL-6, but attenuated TNF-alpha production. Reversible competitive inhibition of PDE4 (rolipram) exhibited a potent inhibitory effect on IL-6 and a dual, biphasic (excitatory/inhibitory) effect on TNF-alpha secretion. Blockading PDE5 (4-3',4'-(methylenedioxy)benzyl amino-6-methoxyquinazoline) showed a high potency in reducing IL-6 production, but in a manner similar to the inhibition of PDE4, exhibited a biphasic effect on TNF-alpha biosynthesis. Simultaneous inhibition of PDE5, 6, and 9 (zaprinast), purported to specifically elevate intracellular cGMP, reduced, in a dose-independent manner, IL-6 and TNF-alpha biosynthesis. Finally, nonselective inhibition of PDE by pentoxifylline suppressed LPS-mediated secretion of IL-6 and TNF-alpha. The involvement of specific PDE isoenzymes in differentially regulating LPS-mediated inflammatory cytokine biosynthesis indicates a novel approach to unravel the potential therapeutic targets that these isozymes constitute during the progression of inflammation within the respiratory epithelium.
Monocytes/macrophages exhibit antitumour potential, but clinicopathological evidence suggests that they may both inhibit and enhance tumour growth. The purpose of this study was to determine the ...effect of monocytes on the growth of human pancreatic cancer (HPC-4) in severe combined immunodeficient (SCID) mice.
Freshly isolated human monocytes or CD14+ cells from cocultures with tumour cells were coengrafted, at various ratios, with HPC-4 cells into SCID mice. The tumour size and angiogenesis were determined.
At a high ratio of monocytes to cancer cells the enhancement and, at a low ratio, the inhibition of tumour growth was observed. Multiple intratumoral applications of monocytes in large numbers also enhanced tumour growth. Deactivation of monocytes by a short pre-exposure to tumour cells in vitro before engraftment led to increased tumour growth. Monocytes used in large numbers and deactivated monocytes in low doses enhanced tumour-induced angiogenesis.
Monocytes may both facilitate and suppress the growth of human tumours in SCID mice and both the number of monocytes, as well as the state of monocyte deactivation are critical for the final outcome of monocyte-tumour interactions.
A case of a male, 17-year-old, X-linked agammaglobulinemia patient with bacteremia caused by Veillonella parvula, without a defined primary site of infection, is presented. The report demonstrates ...that V. parvula should not be regarded as a nonpathogenic microorganism, at least not in patients with certain forms of immunodeficiency disease.
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