Identification and characterization of the monoblast in mononuclear phagocyte colonies grown in vitro

A liquid culture technique for growing mononuclear phagocyte colonies on a glass surface is described. This useful and reliable technique made it possible to study immature mononuclear phagocytes. In the mononuclear phagocyte colonies the cells grow separate from each other in a single layer. Three types of cells are recognized in these colonies, namely nondividing macrophages, and proliferating promonocytes and monoblasts. The macrophage and the promonocyte exhibit the typical characteristics previously demonstrated by the other methods, whereas the monoblast could only be fully characterized by the present liquid culture method. This proliferating cell (labeling index with [3H]thymidine, 92-96%) is almost round (diameters, 10 X 10 mum), has only a small rim of strongly basophilic cytoplasm, almost devoid of granules, and shows a certain degree of ruffling of the cell surface. The monoblast is positive for esterase with alpha-naphthyl butyrate as substrate (91%), for peroxidase (78% in the peroxidase-positive colonies), and lysozyme (43%). The monoblast is able to pinocytize dextran sulphate (15-20%) and to phagocytize opsonized bacteria (20- 30%), latex particles (47%), and IgG-coated red cells (96%). IgG receptors (94%) and complement receptors (16%) are present at the cell surface. In these respects the monoblast has the typical characteristics of the mononuclear phagocytes, but its properties show it to be a more immature cell type than the promonocyte. On the basis of these criteria and the sequence of appearance of the different cell types during incubation and during the development of the individual mononuclear phagocyte colony, monoblasts being present before promonocytes appear in the colony, it is concluded that the monoblast is the precursor of the promonocyte. In these cultures granulocyte colonies are also formed, consisting of myeloblasts, (pro)myelocytes, stabs, and polymorphonuclear neutrophils. Besides the typically tight structure of this kind of colony, the granulocytic cells themselves are quite distinct from the mononuclear phagocytes by their morphology, cytochemical characteristics (e.g. all negative for esterase with alpha- naphthyl butyrate, but 96% positive with N-acetyl DL-alanyl 1- naphthylester), functional characteristics (pinocytic index 13-21%; phagocytic index; for opsonized bacteria 15-36%, for latex particles 10%, and for IgG-coated red cells 0%), and their very small number of IgG receptors and lack of complement receptors. On the basis of these criteria, these granulocytic cells are easily distinguished from the immature cells of the mononuclear phagocyte colonies. The present study confirms the conclusion that the mononuclear phagocytes are a separate cell line, quite distinct from the granulocytic series, since even the most immature cells so far identified--the monoblast and the myeloblast- -have quite different characteristics.     

Regulation of human mononuclear phagocyte migration by cell surface-binding proteins for advanced glycation end products.

Nonenzymatic glycation of proteins occurs at an accelerated rate in diabetes and can lead to the formation of advanced glycation end products of proteins (AGEs), which bind to mononuclear phagocytes (MPs) and induce chemotaxis. We have isolated two cell surface-associated binding proteins that mediate the interaction of AGEs with bovine endothelial cells. One of these proteins is a new member of the immunoglobulin superfamily of receptors (termed receptor for AGEs or RAGE); and the second is a lactoferrin-like polypeptide (LF-L). Using monospecific antibodies to these two AGE-binding proteins, we detected immunoreactive material on Western blots of detergent extracts from human MPs. Radioligand-binding studies demonstrated that antibody to the binding proteins blocked 125I-AGE-albumin binding and endocytosis by MPs. Chemotaxis of human MPs induced by soluble AGE-albumin was prevented in a dose-dependent manner by intact antibodies raised to the AGE-binding proteins, F(ab')2 fragments of these antibodies and by soluble RAGE. When MP migration in response to N-formyl-Met-Leu-Phe was studied in a chemotaxis chamber with AGE-albumin adsorbed to the upper surface of the chamber membrane, movement of MPs to the lower compartment was decreased because of interaction of the glycated proteins with RAGE and LF-L on the cell surface. The capacity of AGEs to attract and retain MPs was shown by implanting polytetrafluoroethylene (PTFE) mesh impregnated with AGE-albumin into rats: within 4 d a florid mononuclear cell infiltrate was evident in contrast to the lack of a significant cellular response to PTFE with adsorbed native albumin. These data indicate that RAGE and LF-L have a central role in the interaction of AGEs with human mononuclear cells and that AGEs can serve as a nidus to attract MPs in vivo.     

Selective expansion of specific T cell receptors in the inflamed colon of Crohn's disease.

To identify disease-specific T cell changes that occur in Crohn's disease (CD), the T cell receptor BV repertoires of lamina propria lymphocytes (LPL) isolated from both the inflamed and "disease-inactive" colons of seven CD patients were compared by the quantitative PCR and DNA sequence analysis. It was observed that the BV repertoires of LPL isolated from the disease-active and disease-inactive parts of the colon from the same individual were very different. Furthermore, nearly all of the differences occurred in CD4+ LPL, with very few differences in the CD8+ population of LPL. Although the pattern of BV segments that was increased in disease-active tissue relative to disease-inactive tissue was different for all seven CD patients, there were several BV segments that increased uniformly in the disease-active tissue of all seven individuals. CDR3 length analysis and DNA sequencing of these BV segments revealed that in six of the seven CD patients there was a striking degree of oligoclonality that was absent from disease-inactive tissue of the same individual. These observations suggest that at least some of the inflammation in CD is the result of responses by CD4+ T cells to specific antigens. The isolation of such inflammation-specific CD4+ T cells may make it possible to identify the antigens that are responsible for the inflammatory process in CD and provide a better understanding of its pathogenesis.     

Effects of therapeutic ultrasound on the activity of the mononuclear phagocyte system in vivo

Therapeutic intensities of continuous wave ultrasound applied over the umbilical area of female rats resulted in a decrease in the rate of removal of 99mtechnetium radio-labelled sulphur colloid by the mononuclear phagocyte system. The magnitude of this effect increased both with increasing intensity of ultrasound and with the duration of exposure, and was found to be dependent upon the total amount of energy deposited within the umbilical area. This effect appeared to be initiated by an effect of ultrasound upon circulating lymphocytes since isolated lymphocytes sonicated in vitro at therapeutic intensities and then injected intravenously resulted in a decrease in the rate of colloid removal in vivo similar to that observed when the umbilical area had been sonicated in vivo. The mechanism by which this is thought to occur is discussed.     

Mononuclear phagocytes have the potential for sustained hydroxyl radical production. Use of spin-trapping techniques to investigate mononuclear phagocyte free radical production

Monocytes lack lactoferrin and have much less myeloperoxidase than neutrophils. They also acquire a potential catalyst for .OH production (tartrate-resistant acid phosphatase) as they differentiate into macrophages. Consequently, the nature of free radicals produced by these cells was examined using the previously developed spin-trapping system. When stimulated with either PMA or OZ neither monocytes nor monocyte-derived macrophages (MDM) exhibited spin trap evidence of .OH formation. Pretreatment with IFN-gamma failed to induce MDM .OH production. When provided with an exogenous Fe+3 catalyst, both stimulated monocytes and MDM, but not PMN, exhibited sustained .OH production, presumably due to the absence of lactoferrin in mononuclear phagocytes. Sustained production of .OH could contribute to the microbicidal activity of mononuclear phagocytes as well as inflammatory tissue damage under in vivo conditions where catalytic Fe+3 may be present.     

Inhibitory effects of 2''-fluorinated arabinosyl-pyrimidine nucleosides on woodchuck hepatitis virus replication in chronically infected woodchucks.

The treatment of woodchuck hepatitis virus infections with 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) and 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAU), given intraperitoneally, caused complete and permanent decrease of serum virus endogenous DNA polymerase and viral DNA in all treated woodchucks but was associated with severe toxicity. By contrast 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-ethyluracil (FEAU) induced a sustained, although less dramatic, decrease of viral replication without apparent toxic effect. FEAU was also effective when given orally. However, in both cases this inhibitory effect was transient.     

Interaction of CD44 and hyaluronan is the dominant mechanism for neutrophil sequestration in inflamed liver sinusoids

Adhesion molecules known to be important for neutrophil recruitment in many other organs are not involved in recruitment of neutrophils into the sinusoids of the liver. The prevailing view is that neutrophils become physically trapped in inflamed liver sinusoids. In this study, we used a biopanning approach to identify hyaluronan (HA) as disproportionately expressed in the liver versus other organs under both basal and inflammatory conditions. Spinning disk intravital microscopy revealed that constitutive HA expression was restricted to liver sinusoids. Blocking CD44-HA interactions reduced neutrophil adhesion in the sinusoids of endotoxemic mice, with no effect on rolling or adhesion in postsinusoidal venules. Neutrophil but not endothelial CD44 was required for adhesion in sinusoids, yet neutrophil CD44 avidity for HA did not increase significantly in endotoxemia. Instead, activation of CD44-HA engagement via qualitative modification of HA was demonstrated by a dramatic induction of serum-derived HA-associated protein in sinusoids in response to lipopolysaccharide (LPS). LPS-induced hepatic injury was significantly reduced by blocking CD44-HA interactions. Administration of anti-CD44 antibody 4 hours after LPS rapidly detached adherent neutrophils in sinusoids and improved sinusoidal perfusion in endotoxemic mice, revealing CD44 as a potential therapeutic target in systemic inflammatory responses involving the liver.     

吗啡对HIV-1在MT2细胞和巨噬细胞中复制的影响

目的 附测定双抗体夹心法检测p24抗原表达.用Student-t检验或方差分析(ANOVA)比较不同细胞处理组间p24抗原表达差异;采用重复测量数据的方差分析比较不同时间吗啡处理组比对照组的p24抗原表达增加或减少倍数的变化趋势.结果 HIV-1感染MT2细胞后第3、4、5和6天,3个浓度的吗啡处理的(1)组的p24抗原表达[第3天:(4.44±0.30)、(5.59±0.25)和(4.60±0.24) ng/ml;第4天:(24.30±2.66)、(31.73±1.17)和(26.02±0.37) ng/ml;第5天:(56.30±1.26)、(81.77±2.49)和(63.66±2.57) ng/ml;第6天:(150.70±8.97)、(243.09±8.93)和(173.72±7.73) ng/ml]均高于(4)组[第3~6天分别为(1.93±0.05)、(8.03±0.09)、(15.30±0.91)、(41.01±0.84) ng/ml],差异有统计学意义(第3天:t值分别为14.15、24.74和19.14,P均<0.01;第4天:t值分别为10.59、34.92和81.2,P均<0.01;第5天:t值分别为45.83、43.51和30.07,P均<0.01;第6天:t值分别为20.09、39.02和29.55,P均<0.01).3个浓度的吗啡处理的(1)组的p24抗原表达比(4)组增加的倍数,随HIV-1感染MT2细胞的时间的延长具有上升的趋势,时间效应具有统计学意义(F=842.18,P<0.01).HIV-1感染巨噬细胞组后第4、6、8和10天,3个浓度的吗啡处理的(5)组的p24抗原表达[第4天:(0.68±0.15)、(0.87±0.41)和(0.75±0.09) ng/ml;第6天:(1.64±0.57)、(2.07±0.12)和(1.75±0.17) ng/ml;第8天:(6.31±0.17)、(8.81±0.34)和(7.19±0.11) ng/ml;第10天:(32.30±17.55)、(50.74±17.55)和(39.74±0.56) ng/ml]均高于(8)组[第4、6、8、10天分别为(0.60±0.01)、(1.16±0.07)、(3.84±0.45)、(17.55±0.86) ng/ml],差异有统计学意义(第4天:t值分别为7.27、11.06和3.02,P均<0.05;第6天:t值分别为8.93、11.3和5.45,P均<0.01;第8天:t值分别为8.83、15.11和12.42,P均<0.01;第10天:t值分别为13.65、17.84和36.69,P均<0.01).3个浓度的吗啡处理的(5)组的p24抗原表达比(8)组增加的倍数,随HIV-1感染时间的延长具有上升的趋势,时间效应具有统计学意义(F=135.58,P<0.01).结论 吗啡能够促进HIV-1在MT2细胞和巨噬细胞内的复制,并且随着感染时间的延长而增加;吗啡促进HIV-1复制的作用可被纳洛酮阻断.

Abstract：

Objective To determine whether Morphine has the ability to enhance HIV-1 replication in MT2 and Macrophage in vitro and assess the influence of Naloxone on Morphine2s effect.Methods MT2 cells were randomly assigned into 4 groups: (1) Morphine treatment for MT2 group, (2) Morphine+Naloxone co-treatment for MT2 group, (3) Naloxone treatment for MT2 group and (4) MT2 Control;Macrophages were also randomly assigned into 4 groups: (5) Morphine treatment for Macrophage group, (6) Morphine+Naloxone co-treatment for Macrophage group, (7) Naloxone treatment for Macrophage group and (8) Macrophage Control. Group (2), (3), (6) and (7) were pre-treated with 10-8 mol/L Naloxone for 0.5 h, and then group (1) and (2) were treated with 10-12, 10-10 and 10-8 mol/L Morphine for 24 h;group (5) and (6) were disposed of 10-10 mol/L Morphine for 24 h.All 8 groups were added in HIV-1 viral strain with 50% tissue culture infective dose(TCID50).P24 antigen in MT2 cells culture supernatant at day 3, 4, 5 and 6, and in Macrophages culture supernatant at day 4, 6, 8, 10 and 12 after infection were determined with ELISA.Student2s t-test and ANOVA were used to compare the differential expression in different groups, and repeated measures ANOVA was used to compare the increasing or decreasing expression of p24 antigen in morphine treatment groups than that in the control group at different time points.Results On the 3rd day of infection with HIV-1 in MT2 cells, the expression of p24 antigen in 10-12, 10-10 and 10-8mol/L dose of group (1) were (4.44?.30), (5.59?.25) and (4.60?.24) ng/ml respectively, compared to control[(1.93?.05) ng/ml, t= 14.15, 24.74 and 19.14, all P<0.01].On the 4th day, 10-12, 10-10 and 10-8mol/L dose of group (1) resulted in a significant increase of p24 antigen expression [(24.30?.66), (31.73?.17) and (26.02?.37) ng/ml]in culture supernatants compared to control[(8.03?.09) ng/ml, t=10.59, 34.92 and 81.2, all P<0.01].On the 5th day, the expression of p24 antigen in 10-12, 10-10 and 10-8 mol/L dose of group (1) were (56.30?.26), (81.77?.49) and (63.66?.57) ng/ml respectively, compared to control [(15.30?.91) ng/ml, t= 45.83, 43.51 and 30.07, all P<0.01].On the 6th day, the expression of p24 antigen in 10-12, 10-10 and 10-8 mol/L dose of group (1) were (150.70?.97), (243.09?.93) and (173.72?.73) ng/ml respectively, compared to control [(41.01?.84) ng/ml, t= 21.09, 39.02 and 29.55, all P<0.01].The enhanced multiple of p24 antigen expression in three doses of morphine treatment group compared to control increased with HIV-1 infected MT2 cells time, trend analysis of repeated measurements showed statistically significant time effect (F=842.18, P<0.01). On the 4th day of infection with HIV-1 in Macrophage cells, the expression of p24 antigen in 10-12, 10-10 and 10-8 mol/L dose of group (5) were (0.68?.15), (0.87?.41) and (0.75?.09) ng/ml respectively, compared to control [(0.60?.01) ng/ml, t= 7.27, 11.06 and 3.02, all P<0.05]. On the 6th day, 10-12, 10-10 and 10-8 mol/L dose of group (5) resulted in a significant increase of p24 antigen expression[(1.64?.57) , (2.07?.12 ) and (1.75?.17) ng/ml]in culture supernatants compared to control [(1.16?.07) ng/ml, t=8.93, 11.3 and 5.45, all P<0.01].On the 8th day, the expression of p24 antigen in 10-12, 10-10 and 10-8 mol/L dose of group (5) were (6.31?.17), (8.81?.34) and (7.19?.11) ng/ml respectively, compared to control [(3.84?.45) ng/ml, t=8.83, 15.11 and 12.42, all P<0.01]. On the 10th day, the expression of p24 antigen in 10-12, 10-10 and 10-8 mol/L dose of Morphine treated group were (32.30?7.55), (50.74?7.55) and (39.74?.56) ng/ml respectively, compared to control [(17.55?.86) ng/ml, t= 13.65, 17.84 and 36.69, all P<0.01].The enhanced multiple of p24 antigen expression in three doses of group (5) compared to control increased with HIV-1 infected Macrophage cells time, trend analysis of repeated measurements showed statistically significant time effect (F=135.58, P<0.01).Conclusions Morphine has the ability to enhance HIV-1 replication in MT2 cell and Macrophage. This Morphine-mediated increase of p24 antigen expression can be blocked by Naloxone.     

巨噬细胞极化在脓毒症免疫机制中的作用

脓毒症是由于感染引起的免疫功能失调,最终导致的多脏器功能障碍综合征。巨噬细胞作为先天性免疫和适应性免疫的重要组成成分之一,当微环境变化时,可分化成具有不同功能的表型,称为巨噬细胞极化。巨噬细胞极化在脓毒症的免疫调节中发挥重要作用,调控巨噬细胞极化有望成为未来脓毒症治疗的新靶点。因此,本文就巨噬细胞极化及其在脓毒症免疫机制中的作用进行综述。     

Hematological characterization of congenital osteopetrosis in op/op mouse. Possible mechanism for abnormal macrophage differentiation

Compared with normal littermates, the op/op mice had very few macrophages in the peritoneal cavity and severely reduced numbers of monocytes in the peripheral blood. Moreover, osteopetrotic animals demonstrated an altered distribution of hemopoietic tissue with a 10- fold decrease in the number of marrow cells. Liver hemopoiesis persisted in 4-wk-old mice as evidenced by the presence of hemopoietic stem cells (HSC). Moreover, the concentration of HSC was decreased in marrow and increased in the spleen of op/op mice. In spite of the paucity of cells of monocyte-macrophage lineage in vivo, progenitor cells from hemopoietic tissues of op/op mice formed increased numbers of monocyte-macrophage colonies in vitro in the presence of exogenous colony-stimulating activity (CSA). The source of this critical CSA was a medium conditioned by stromal fibroblastoid colonies formed in vitro by normal marrow cells. Therefore, these data suggest that op/op mice possess normal monocyte-macrophage-osteoclast progenitor cells but these cells are unable to fully differentiate in the op/op mouse microenvironment. In support of this, in cultures of stromal fibroblastoid colonies from op/op marrow or spleen, the concomitant growth of macrophages, normally very dense, was drastically reduced. Moreover, transplantation of op/op spleen cells into lethally irradiated littermate recipients resulted in their hemopoietic reconstitution without signs of macrophage defect. Thus, the op/op splenic cells do not transfer the disease and are capable of normal differentiation in normal in vivo environment. These observations support the hypothesis that the defect in op/op mice is a result of the failure of hemopoietic stromal fibroblastoid cells to release sufficient amounts of CSA necessary for normal differentiation of cells of the monocyte-macrophage lineage.     

A macrophage invasion mechanism for mycobacteria implicating the extracellular domain of CD43

We studied the role of CD43 (leukosialin/sialophorin), the negatively charged sialoglycoprotein of leukocytes, in the binding of mycobacteria to host cells. CD43-transfected HeLa cells bound Mycobacterium avium, but not Salmonella typhimurium or Shigella flexneri. Quantitative bacteriology showed that macrophages (M(phi)) from wild-type mice (CD43(+/+)) bound M. avium, Mycobacterium bovis (bacillus Calmette-Guérin), and Mycobacterium tuberculosis (strain H37Rv), whereas M(phi) from CD43 knockout mice (CD43(-/)-) did not. Fluorescence microscopy demonstrated that the associated M. avium had been ingested by the CD43(+/+) M(phi). The inability of CD43(-/)- M(phi) to bind M. avium could be restored by addition of galactoglycoprotein (Galgp), the extracellular mucin portion of CD43. The effect of Galgp is not due to opsonization of the bacteria, but required its interaction with the M(phi) other mucins had no effect. CD43 expression by the M(phi) was also required for optimal induction by M. avium of tumor necrosis factor (TNF)-alpha production, which likewise could be reconstituted by Galgp. In contrast, interleukin (IL)-10 production by M. avium-infected M(phi) was CD43 independent, demonstrating discordant regulation of TNF-alpha and IL-10. These findings describe a novel role of CD43 in promoting stable interaction of mycobacteria with receptors on the M(phi) enabling the cells to respond specifically with TNF-alpha production.