Expression of surface antigen and mRNA for the CD11c (alpha X, p150) subunit of the human leukocyte adherence receptor family in hematopoietic cells

We characterized the surface antigen and mRNA expression for the CD11c (alpha X, p150) subunit of the human leukocyte adherence receptor family during hematopoietic cell differentiation. The CD11c subunit antigen and mRNA are constitutively expressed in undifferentiated HL-60 promyelocytic leukemia cells, and levels increase markedly with differentiation along the monocyte/macrophage pathway using phorbol myristate acetate. Human monocyte-derived macrophages and human alveolar macrophages express elevated levels of the CD11c subunit antigen and mRNA, indicating that the changes observed in vitro are present in vivo. Dot blot analysis of immature and mature lymphoid and myeloid cells and cell lines demonstrate equivalent levels of CD11c mRNA expression. We conclude that CD11c gene expression is selectively increased during hematopoietic cell differentiation along the monocyte/macrophage pathway.     

Chicken hematopoietic cells transformed by seven strains of defective avian leukemia viruses display three distinct phenotypes of differentiation.

Chicken hematopoietic cells transformed in vitro and in vivo by seven strains of replication-defective avian leukemia viruses were assayed for the expression of six erythroid and five myeloid differentiation parameters, including differentiation-specific surface antigens as detected by newly developed antisera. The transformed cells were found to display three distinct phenotypes of differentiation. First, cells transformed by AEV resemble erythroblasts. They express heme, globin, carbonic anhydrase and erythrocyte cell surface antigen at low levels, and histone H5 and erythroblast cell surface antigen at high levels. Second, cells transformed by MC29, CMII, OK10 and MH2 viruses have macrophage-like properties. They strongly express Fc receptors, phagocytic capacity and macrophage cell surface antigen, but only weakly express myeloblast cell surface antigen and are negative for ATPase activity. Third, cells transformed by AMV and E26 viruses resemble myeloblasts in that they weakly express Fc receptors, phagocytic capacity and macrophage cell surface antigen but strongly express myeloblast cell surface antigen and ATPase activity. No difference was found between in vitro- and in vivo-transformed cells in the parameters tested. In light of recent genetic and biochemical evidence, we believe that these phenotypes reflect the action of three new types of viral-transforming genes, designated erb (erythroblast), mac (macrophage) and myb (myeloblast).     

Differentiation of simian virus 40 transformed human mammary epithelial stem cell lines to myoepithelial-like cells is associated with increased expression of viral large T antigen

Cloned simian virus 40 (SV40)-transformed human breast epithelial cell lines can differentiate to myoepithelial-like cells, and these can be isolated as clonal cell lines. Immunofluorescent and immunocytochemical analysis of such cell lines growing on plastic surfaces, collagen gels, and as tumor-nodules in nude mice indicate that all the cell lines produce SV40 large T antigen, but that the production of this antigen is qualitatively increased in the myoepithelial-like cells and cell lines. The myoepithelial-like cell lines produce 4-6 times more immunoprecipitable large T antigen than the parental epithelial cells. The amount of mRNA for large T antigen is also increased by 3.5-5-fold in the myoepithelial-like cell lines when analysed by dot-blot or by Northern hybridisations. Thus, differentiation along the myoepithelial-like cell pathway is associated in these SV40-transformed cells with increased expression of the viral large T antigen. It is suggested that immortalization of primary breast epithelial cell cultures may be, in part, due to the expression of large T antigen preventing processes of terminal keratinization.     

Modulation of phenotype in cultures of human milk epithelial cells and its relation to the expression of a membrane antigen

Primary cultures of human milk epithelial cells, labelled with HMFG-1, a monoclonal antibody that recognises a differentiation antigen on the membranes of breast epithelia, were separated from unlabelled cells in a fluorescence-activated cell sorter (FACS). Cells not expressing the HMFG-1 antigen have a greater in vitro growth potential than the positive ones, and give rise to cultures containing both HMFG-1 antigen positive and negative cells. The cultures derived from negative cells usually contain colonies with 'open' cuboidal cells and these do not express the HMFG-1 antigen. However, when they differentiate into other phenotypes such as the 'closed' cuboidal cell type, expression of the differentiation antigen becomes evident and the cultures then show a reduced growth potential. When milk cells are subcultured several times, a new cell type emerges which does not express the HMFG-1 antigen or the intermediate filaments typical of epithelial cells but instead express high levels of fibronectin which is found in an extracellular matrix. Whether these cells emerge by selection of an existing phenotype or by phenotypic modulation is discussed.     

Regulation and specificity of MNDA expression in monocytes,macrophages, and leukemia/B lymophoma cell lines

The expression of the human myeloid cell nuclear differentiation antigen (MNDA) was observed specifically in cells of the granulocyte-macrophage lineage in our earlier reports. The specificity of MNDA expression for cells in the granulocyte-macrophage lineage was reexamined in cell line established from patients with philadelphia chromosome-positive chroni myeloid leukemia. Cell lines that expressed MNDA exhibited myeloid cell features and granulocyte or monocyte defferentiation could be induced in vitro, while cell lines exhibiting properties of very early stage cells of multipotential cells ded not express MNDA. Cells orginating from cases of burkitt's lymphoma were negative. By contrast, three Iymphoblastoid cell lines (immortalized in vitro with Epstein-Barr virus) were weakly positive and MNDA was up-regulated by interferon-α (IFN-α) treatment. As we reported previously, MNDA mRNA level in adherent monocytes is elevated by IFN-α; in this study, we further assessed MNDA expression in in vitro monocyte-derived macrophages. Three addditional agents (endotoxin, phytohemagglutinin, and photbol ester) and other conditions that affect function, cutokine production, defferentiation, and/of growth of monocytes were examined for their ability to alter MNDA expression. The results varied with the agent, cell type, and stage of differentiation. Changes in MNDA expression occurred slowly (hours to days), suggesting that MNDA could mediate changes realized over a long period. The results also reveal a discordance in certain MNDA Positiva cells between steady-state levels of changes in levels of protein and mRNA indicating that the regulation of MNDA expression occurs at more than one point. Changes in MNDA expression are consistent with a role in opposing macrophage defferentiation and activation of monocytes/macrophages.     

Cytotoxic activity against maedi-visna virus-infected macrophages.

The cell type predominantly infected by maedi-visna virus (MVV) is the macrophage, and we have looked at the ability of MVV-infected macrophages to interact with cytotoxic T lymphocytes (CTL), important effector cells against virus infections. MVV-specific CTL precursors were detected, after in vitro culture with MVV antigen and recombinant human interleukin-2, in peripheral blood lymphocytes of all MVV-infected sheep. MVV-infected monocyte-derived macrophages and alveolar macrophages were able to stimulate CTL activity in vitro and were targets for these activated CTL. The major effector cell population using MVV-infected macrophage targets was CD8+ lymphocytes, although another population, lymphokine-activated killer cells, may also have been involved. There was no direct cytotoxic activity found in alveolar lymphocytes from MVV-infected sheep without lung lesions.     

Differentiation of the IL-3-dependent NFS-60 cell line and adaption to growth in macrophage colony-stimulating factor

Macrophage CSF (M-CSF) induces responsive bone marrow precursors into rapid growth and differentiation to mature macrophages. Available cell lines that depend on M-CSF for growth are well differentiated and rather adherent. We investigated the effects of M-CSF on immature myeloid cell lines as models of the marrow precursors. The murine line NFS-60 requires IL-3 for growth and also responds to granulocyte-CSF and granulocyte-macrophage-CSF. Cultures of one NFS-60 subline, when switched from IL-3 to 10% L cell conditioned media, a source of M-CSF, or purified M-CSF, frequently acquired large, adherent cells. The adherent cells grew slowly in the presence of M-CSF, in contrast to the majority population of small, round, rapidly growing cells. The large cells had properties of differentiated macrophages that were absent in the nonadherent cells. Cells with macrophage phenotype were not observed in IL-3-supported cultures over many passages. A subline was derived from NFS-60 that grew rapidly and continuously in human or murine M-CSF as round, nonadherent cells. The line, called M-NFS-60, responded well to M-CSF and IL-3, weakly to granulocyte-CSF and not at all to murine granulocyte-macrophage-CSF, IL-4, or human IL-1. A mAb to human M-CSF specifically inhibited only M-NFS-60 proliferation induced by the human growth factor, whether produced by mammalian or bacterial cells. This study shows two effects of M-CSF on the IL-3-dependent NFS-60 line. Upon first exposure to M-CSF, cells may undergo global differentiation to slowly replicating macrophages in conditions we have not been able to define. The more common effect is rapid growth of immature myeloid cells like the bone marrow precursors, but with a block to differentiation. Thus, these cells may be useful as models of M-CSF-induced differentiation, and of permanently maintained macrophage precursors.     

Tp44 molecules involved in antigen-independent T cell activation are expressed on human plasma cells

We have analyzed cells of the B lineage for expression of the Tp44 antigen, a 44,000 homodimer detected by monoclonal antibody 9.3 on approximately 80% of mature human T lymphocytes. Previous evidence has suggested that Tp44 may function as a receptor for accessory signals in T cell activation. High level Tp44 expression was observed on plasmacytomas grown in cell culture and on plasma cells from bone marrow biopsies of multiple myeloma patients. This antigen is not present on resting B cells from either peripheral blood or lymphoid organs, or on any other B cell tumor. The growth kinetics and Ig production in plasmacytomas are not affected by the binding of antibody 9.3. Moreover, the Tp44 molecule is co-expressed with PCA-1, an antigen characteristic of plasma cells, on peripheral blood B cells stimulated in vitro to differentiate toward plasma cells. Tp44 may represent a later stage of B cell differentiation than PCA-1 because unlike the PCA-1 antigen, this molecule could not be detected on any EBV-transformed cell line or Burkitt's lymphoma lines. The m.w. of the Tp44 molecule expressed on plasma cells and on T cells is identical, as determined by immunoprecipitation of radioiodinated cell surface proteins with monoclonal antibody 9.3. This antigen might be useful in studying the mechanism of growth and differentiation of human B cells, the heterogeneity within plasma cell populations, and B cell interactions with other components of the immune system.     

A monoclonal antibody with reactivity restricted to normal and neoplastic plasma cells

A monoclonal antibody that defines a new and distinct plasma cell antigen, termed PC-1, was developed against human plasmacytoma cells. This antigen is strongly expressed on normal plasma cells isolated from bone marrow and on abnormal plasma cells isolated from myelomas, plasma cell leukemias, and plasmacytomas. The antigen is not detected on normal T or B lymphocytes, granulocytes, or monocytes, and with the exception of plasma cells, is absent on malignancies of B, T, or myeloid origin. Utilizing pokeweed mitogen to induce human B lymphocyte differentiation in vitro, PC-1 is expressed when B cell determinants are lost and the plasmacytoid morphology, intracytoplasmic immunoglobulin-staining, and surface PCA-1- and T10-staining characteristic of plasma cells appear. This antigen is useful for the study of the terminal stages of normal B cell differentiation to plasma cells, and may offer insight into the heterogeneity of the plasma cell dyscrasias.     

Specific binding of T lymphocytes to macrophages. II. Role of macrophage-associated antigen.

Peritoneal exudate lymphocytes from immune guinea pigs that bind in vitro to autologous antigen-pulsed macrophages were allowed to proliferate for 1 week to give a population markedly enriched in antigen-specific T cells. This enriched population was then studied with regard to its binding to fresh autologous antigen-pulsed macrophages. Specific binding was not inhibited by a large excess of antigen in the media (5000-fold greater than the amount of antigen associated with the macrophages) either soluble or bound to Sepharose beads, or by coating the antigen-pulsed macrophags with antibody to the exogenous antigen, by reacting a second layer of antibody to the heterologous antibody, or by haptenating the antigen and treating the hapten-antigen macrophage complex with excess anti-hapten antibody. Results of treating antigen-pulsed macrophages with the proteolytic enzymes trypsin and pronase indicate that exogenous antigen is on the macrophage surface, but the experiments failed to prove that the removable antigen is essential for binding. The simplest interpretation of these results is that the T cell receptor is not specific for native exogenous antigen.     

Accessory cell function of cells isolated from Mycobacterium leprae-induced granulomas

The large cells from Mycobacterium leprae-induced granulomas in guinea pig lymph nodes were separated by Percoll discontinuous density gradient centrifugation and on a fluorescence-activated cell sorter (FACS) using cross-reacting monoclonal antibody to human MHC Class II antigens. Large Percoll-separated cells (83% Class II antigen positive and 52% macrophage-specific antigen positive) and FACS-separated cells are able to act as antigen-presenting cells for T-cell proliferation to PPD. In previous studies, macrophage antigen-positive cells consistently failed to act as accessory cells. This indicates that there is a population of accessory cells which are macrophage antigen negative and MHC Class II antigen positive present in these M. leprae-induced granulomas.     

Species-dependent regulation of monocyte/macrophage Ia antigen expression and antigen presentation by prostaglandin E

The expression of Ia antigen by various murine and human macrophage populations and the ability of prostaglandins of the E series to regulate Ia antigen expression were explored. Monocytes and macrophages from human and murine populations demonstrated a dichotomy in the expression of Ia antigen. Both human monocytes and macrophages expressed elevated levels of Ia antigen compared to their murine counterpart. Murine macrophages appear to express elevated levels of Ia antigen only when actively interacting with T lymphocytes in vivo or with lymphokines in vitro. Prostaglandins of the E series can suppress murine macrophage Ia antigen expression, but have little effect on the expression of Ia antigen by human monocytes and macrophages. Also, prostaglandins of the E series do not modulate the ability of human monocytes to present antigen to autologous lymphocytes when studied over a broad concentration range. These data suggest that prostaglandin E compounds do not profoundly affect human monocyte/macrophage Ia antigen expression or human monocyte antigen presenting activity.     

Identification of MS4A3 as a reliable marker for early myeloid differentiation in human hematopoiesis

Information of myeloid lineage-related antigen on hematopoietic stem/progenitor cells (HSPCs) is important to clarify the mechanisms regulating hematopoiesis, as well as for the diagnosis and treatment of myeloid malignancies. We previously reported that special AT-rich sequence binding protein 1 (SATB1), a global chromatin organizer, promotes lymphoid differentiation from HSPCs. To search a novel cell surface molecule discriminating early myeloid and lymphoid differentiation, we performed microarray analyses comparing SATB1-overexpressed HSPCs with mock-transduced HSPCs. The results drew our attention to membrane-spanning 4-domains, subfamily A, member 3 (Ms4a3) as the most downregulated molecule in HSPCs with forced overexpression of SATB1. Ms4a3 expression was undetectable in hematopoietic stem cells, but showed a concomitant increase with progressive myeloid differentiation, whereas not only lymphoid but also megakaryocytic-erythrocytic progenitors were entirely devoid of Ms4a3 expression. Further analysis revealed that a subset of CD34⁺CD38⁺CD33⁺ progenitor population in human adult bone marrow expressed MS4A3, and those MS4A3⁺ progenitors only produced granulocyte/macrophage colonies, losing erythroid colony- and mixed colony-forming capacity. These results suggest that cell surface expression of MS4A3 is useful to distinguish granulocyte/macrophage lineage-committed progenitors from other lineage-related ones in early human hematopoiesis. In conclusion, MS4A3 is useful to monitor early stage of myeloid differentiation in human hematopoiesis.     

Cell growth and differentiation in vitro in mouse macrophages transformed by a tsA mutant of simian virus 40. I. Cellular response in proliferative and phagocytic activities to the shift of temperature differs depending on the culture state in mouse bone marrow cells transformed by the tsA640 mutant of simian virus 40

It was shown previously that mouse bone marrow cells transformed by simian virus 40 (SV40) show a reversible cell density-dependent phenotypic transition between the nonmacrophage (rapidly growing) and the macrophage (stationary) states; cells in low-density cultures are in the growing phase, express SV40 T antigen strongly as revealed by immunofluorescence, and lose typical macrophage properties such as immune phagocytosis; whereas cells in high-density cultures are in the stationary (nongrowing) phase, express SV40 T antigen weakly, and recover their macrophage properties (Takayama, 1980). In the hope of clarifying the relationship between T antigen, cell growth, and macrophage-specific cellular function, we examined the behavior at 33 and 39 degrees C of mouse bone marrow cells transformed by an SV40 gene A mutant (tsA640) whose mutation renders the molecular weight of 90K (large) T antigen temperature sensitive. The results presented in this paper suggest that functional large T antigen is required for cells in the stationary phase to initiate multiplication when transferred at lower density and is not necessary for a majority of them to maintain the nongrowing state (viability) at both high and lower cell densities, whereas it is required for cells in the growing phase to keep multiplying without losing their viability. The results also suggest that the functional large T antigen does not play a direct role in maintaining the cells as either phagocytic or nonphagocytic. It is also suggested that the physiological or tsA mutation-mediated arrest of growth may or may not be accompanied by induction and/or maintenance of cellular phagocytic activity depending on the culture state.     

Monocyte-macrophage differentiation in three dimensional collagen lattice

Human peripheral blood mononuclear cells (PBMC) upon transendothelial migration interact with subendothelial matrix components and differentiate into macrophages. In order to study whether the shape of the cells as dictated by the extracellular matrix can influence monocyte-macrophage (mo-m(phi)) differentiation, human PBMC were maintained in vitro on a three dimensional collagen I (COL I) lattice and studied for various macrophage specific functions, viz. endocytosis of [(125)I]acetyl bovine serum albumin (BSA), expression of specific cell surface antigens and expression of matrix metalloproteinases (MMPs). The cells maintained in three dimensional COL gel exhibited a higher rate of endocytosis of [(125)I]acetyl BSA than those on COL-coated plastic. FACS analysis showed that the mean fluorescence intensity (MFI) corresponding to monocyte specific LPS receptor CD14 was significantly decreased while MFI corresponding to macrophage specific transferrin receptor CD71 was significantly increased in cells maintained in vitro on three dimensional COL gel compared to two dimensional COL substrata. Expression of macrophage specific MMPs (gelatinase A and gelatinase B) was significantly high in cells maintained on COL gel than on COL I-coated plastic. Appearance of 67 kDa gelatinase in the COL gel suggested that induction as well as activation of MMPs occur when cells are maintained in a three dimensional environment. These results indicate that monocytes undergo a rapid rate of differentiation when maintained in vitro on three dimensional COL I lattice suggesting that apart from the chemical nature of the matrix, the shape of the cells as provided by the matrix also influences mo-m(phi) differentiation.     

Aleutian mink disease parvovirus infection of mink peritoneal macrophages and human macrophage cell lines.

Aleutian mink disease parvovirus (ADV) mRNAs are found in macrophages in lymph nodes and peritoneal exudate cells from ADV-infected mink. Therefore, we developed an in vitro infection system for ADV by using primary cultures of mink macrophages or macrophage cell lines. In peritoneal macrophage cultures from adult mink, virulent ADV-Utah I strain showed nuclear expression of viral antigens with fluorescein isothiocyanate-labeled ADV-infected mink serum, but delineation of specific viral proteins could not be confirmed by immunoblot analysis. Amplification of ADV DNA and production of replicative-form DNA were observed in mink macrophages by Southern blot analysis; however, virus could not be serially propagated. The human macrophage cell line U937 exhibited clear nuclear expression of viral antigens after infection with ADV-Utah I but not with tissue culture-adapted ADV-G. In U937 cells, ADV-Utah I produced mRNA, replicative-form DNA, virion DNA, and structural and nonstructural proteins; however, virus could not be serially passaged nor could [3H]thymidine-labeled virions be observed by density gradient analysis. These findings indicated that ADV-Utah I infection in U937 cells was not fully permissive and that there is another restricted step between gene amplification and/or viral protein expression and production of infectious virions. Treatment with the macrophage activator phorbol 12-myristate 13-acetate after adsorption of virus reduced the frequency of ADV-positive U937 cells but clearly increased that of human macrophage line THP-1 cells. These results suggested that ADV replication may depend on conditions influenced by the differentiation state of macrophages. U937 cells may be useful as an in vitro model system for the analysis of the immune disorder caused by ADV infection of macrophages.     

Effects of transforming growth factor beta, tumor necrosis factor alpha, interferon gamma and LIF-HILDA on the proliferation of acute myeloid leukemia cells

A group of polypeptide factors that regulate cell growth and differentiation has been tested for their biological activities on the growth and differentiation of leukemic cells isolated from patients with Acute Myeloid Leukemias (AML). The effects of Transforming Growth Factor beta 1 (TGF beta), Tumor Necrosis Factor alpha (TNF alpha), Interferon gamma (IFN gamma) and LIF-HILDA were compared on leukemic cells cultured in vitro for seven days. Spontaneously growing leukemic cells were selected in order to study either inhibition or enhancement of proliferation induced by these factors. Only TGF beta 1 was found to induce a clear inhibition of leukemic proliferation in all cases tested. Recombinant TNF alpha and IFN gamma were found to induce either inhibition or enhancement of the proliferation on separate specimens. Under the conditions of culture, it was not possible to document any effect of LIF-HILDA. Cell differentiation and cell maturation were documented studying the modulation of cell surface antigens. TGF beta did not modify antigen expression on the cells surviving after 3 days in culture. Both TNF alpha and IFN gamma were found to enhance the expression of adhesion molecules and to a lesser extent, the expression of some lineage associated antigens. No effect of LIF-HILDA on antigen modulation was documented in the cases tested. These data confirm that TGF beta is by itself a potent inhibitor of the myeloid leukemia cells proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Size-dependent B lymphocyte subpopulations: relationship of cell volume to surface phenotype, cell cycle, proliferative response, and requirements for antibody production to TNP-Ficoll and TNP-BA

Murine splenic B lymphocytes were separated into size-dependent subpopulations by using counterflow centrifugation. Spleen cells were rigorously depleted of T lymphocytes to yield a population of cells that were greater than 90% surface immunoglobulin (Ig)-positive and that had a mean cell volume of 136.6 +/- 3.3 microns. From this population, five fractions of cells were obtained with mean cell volumes that ranged from 115.8 +/- 3.7 microns in fraction 1 to 168.0 +/- 6 microns in fraction 5. The cells in these five subpopulations were characterized by analysis on a fluorescence-activated cell sorter after staining with acridine orange to evaluate RNA and DNA content, and with fluorescein-conjugated anti-mu, anti-delta, and anti-Ia antibodies to evaluate their surface membrane phenotypes. DNA analysis revealed that virtually all of the cells in fractions 1 to 4 had 2 N DNA. Between 7 and 21% of fraction 5 cells were either in S-phase or contained 4 N DNA. In contrast, RNA content increased through the fractions, suggesting a transition from G0 to G1 in the subpopulations with increasing B cell size. As another measure of cell activation seen with increasing cell size, we observed a progressive increase in the expression of surface Ia and a decrease in the expression of surface IgD. In the absence of in vitro stimulation, the larger cells showed significantly higher levels of thymidine incorporation. When polyclonal B cell activators such as LPS or anti-Ig antibody were added, peak proliferative responses were similar in all of the fractions, but the time necessary to achieve a maximal response was shorter for the larger-sized cell subpopulations than it was for the smaller-sized cell subpopulations. Unprimed, size-dependent B lymphocyte subpopulations exhibited spontaneous or "background" antibody formation that occurred primarily in the subpopulations containing the largest cells. T cell factors present in EL4 supernatant enhanced the efficiency of in vitro differentiation of these same subpopulations. When cultured in the absence of T cell help, the thymus-independent type 1 (TI-1) antigen TNP-Brucella abortus (TNP-BA) or the thymus-independent type 2 (TI-2) antigen TNP-Ficoll induced the largest anti-TNP plaque-forming cell (PFC) responses in the fractions containing intermediate-sized cells, suggesting that in vitro, antigen-specific responses came primarily from B cells that have been influenced in vivo to leave their small resting state. The subpopulations containing the smallest size B cells required the presence of both a TI antigen and EL4 supernatant for efficient differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)