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Mast cell typing: demonstration of a distinct hematopoietic cell type and evidence for immunophenotypic relationship to mononuclear phagocytes.

The immunologic surface marker profile of human mast cells (MCs) was established using a combined toluidine/immunofluorescence staining procedure [49 monoclonal antibodies (MoAbs) tested]. Ascites (n = 9) MCs as well as enzymatically dispersed MCs from all organs tested (lung n = 11, skin n = 7, intestinum n = 10) exhibited an identical marker profile. MCs were recognized by MoAbs clustered as CD9 (anti-gp24), CD33 (anti-gp67), and CD45 (anti-gp220) as well as by MoAbs directed against membrane-bound IgE. MoAB YB5B8 (anti-gp145) selectively recognized MCs. Most significantly, however, MCs were stained by MoAbs MAX1 (anti-gp65), MAX3 (anti-gp68), MAX11 (anti-gp65), and MAX24 (anti-gp65). These antibodies bind to surface membrane antigens associated with a late stage of monocyte/macrophage differentiation. Thus, our results provide definite evidence that MCs share surface membrane markers with mononuclear phagocytes. In contrast, MCs are stained neither by lymphatic markers (CD1-8, 10, 19-24) nor by myelomonocytic markers (CD11-17). MCs also lack the interleukin-2 (IL-2) receptor (CD25), the T10 antigen (CD38), and most of the myelocytic markers expressed on peripheral blood (PB) basophils. Thus, MCs displayed a unique phenotype within the hematopoietic system. This new approach enabled us to enrich human lung MCs to a purity greater than 95% by means of negative selection with complement-mediated cell lysis. Purified MCs were subsequently stained with MoAbs and analyzed by flow cytometry, which confirmed the results obtained from the double-staining experiments. We next examined cultured metachromatic cells derived from bone marrow (BM) and peripheral blood colony-forming units (CFU). These metachromatic cells previously could not be classified by morphologic criteria alone and have therefore been termed basophil-like/MC-like cells. In this study, toluidine blue-positive cells obtained from either pooled multipotential colonies (day 14-CFU-GEM) or pooled myelocytic colonies (day 16/17-CFU-GM/G/M) were recognized by MoAbs MY7 (CD13), VIM12 (CD11b), and VIM2, as well as by an anti-IgE MoAb, after preincubation with IgE. In contrast, CFU-derived metachromatic cells were not stained by MoAb YB5B8. This marker profile corresponds to the immunologic phenotype of blood basophils and excluded a detectable formation of mature MCs in colonies derived from cultured hematopoietic stem cells.

Antigens, Surface↗

Involvement of CCR5 in the passage of Th1-type cells across the blood-retina barrier in experimental autoimmune uveitis.

Although the recruitment of T helper cell type 1 (Th1)/Th2 cells into peripheral tissues is essential for inflammation and the host response to infection, the traffic signals that enable the distinct positioning of Th1/Th2 cells are unclear. We have determined the role of CC chemokine receptor 5 (CCR5) in this using experimental autoimmune uveitis (EAU) as a model system. In EAU, Th1-like cells are preferentially recruited into the retina across the blood-retina barrier, partly as a result of expression of the adhesion molecules P-selectin glycoprotein ligand 1 and lymphocyte function-associated antigen-1 on these cells. CD3+ T cells, infiltrating the retina, also expressed the chemokine receptor CCR5, and CCR5 ligands, macrophage-inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and regulated on activation, normal T expressed and secreted (RANTES), were strongly expressed in the retina at peak EAU. Th1-like cells, polarized in vitro, expressed high levels of CCR5. The trafficking of these CCR5+ cells was examined by tracking them after adoptive transfer in real time in vivo at an early disease stage using scanning laser ophthalmoscopy. Treatment of the cells with antibody against CCR5 prior to transfer resulted in a reduction in their infiltration into the retina. However, rolling velocity, rolling efficiency, and adherence of the cells to retinal endothelium were not reduced. CCR5 is clearly important for Th1 cell recruitment, and this study demonstrates for the first time in vivo that CCR5 may act at the level of transendothelial migration rather than at the earlier stage of rolling on the endothelium.

Adoptive Transfer↗

The yeast cell-type-specific repressor alpha 2 acts cooperatively with a non-cell-type-specific protein.

The yeast alpha 2 protein is a cell-type-specific transcriptional repressor. It acts by binding to an operator located upstream of each of its target genes. In this paper, we describe a protein (GRM) that is present in all cell types and binds cooperatively with alpha 2 resulting in an unusual arrangement of the two proteins at the operator. A dimer of alpha 2 occupies the two ends of the operator and straddles the GRM protein, which binds to the center of the operator. Using mutant operators, we show that the recognition sequences for both GRM and alpha 2 are required for repression of a test promoter in vivo. Finally, we deduce that the GRM/alpha 2 cooperativity is mediated through a protein-protein interaction between GRM and the N-terminal domain of alpha 2. This conclusion follows from the observation that the isolated C-terminal domain of alpha 2 can co-occupy the operator with GRM but does not bind cooperatively with GRM.

Base Sequence↗

Cell-type-specific regulation of nerve growth factor (NGF) synthesis in non-neuronal cells: comparison of Schwann cells with other cell types.

We have previously shown that after peripheral nerve lesion the synthesis of NGF is induced in cells of the nerve sheath (Heumann et al., 1987a). Further analysis led to the identification of growth factors and intracellular mechanisms responsible for this induction in sciatic fibroblasts (Lindholm et al., 1988; Hengerer et al., 1990). The present work aimed at the elucidation of the regulation of NGF synthesis in Schwann cells. A variety of cytokines and peptide growth factors, including interleukin-1 (IL-1) and platelet-derived growth factor (PDGF), which are known to increase NGF-mRNA in fibroblasts and astrocytes, failed to do so in Schwann cell cultures. Forskolin (FK), an activator of adenylate cyclase, increased the level of NGF-mRNA eightfold within 3 hr of incubation. The effect of FK on NGF-mRNA was mimicked by analogs of cAMP but not by dideoxyforskolin, an FK derivative not activating adenylate cyclase. Application of norepinephrine and isoproterenol also augmented the NGF-mRNA content. Pretreatment of Schwann cells with N-[2-(methylamino)ethyl]-5-isoquinoline sulfonamide dihydrochloride (H-8), an inhibitor of cyclic-nucleotide-dependent protein kinases, decreased both basal and elevated levels of NGF-mRNA. Ionomycin, a Ca2+ ionophore, and phorbol 12-myristate 13-acetate (TPA), an activator of protein kinase C, potentiated the effect of FK in an H-8-sensitive manner. We show that the action of FK is independent of changes in mRNA stability and of protein synthesis. Thus, in cultured Schwann cells upregulation of NGF-mRNA expression seems to be mainly achieved by a cAMP-triggered transcriptional activation of the NGF gene. Another striking difference between various glial cell types was revealed by application of transforming growth factor beta-1 (TGF-beta 1), which is the strongest inducer of NGF-mRNA in cultured astrocytes (Lindholm et al., 1990). Schwann cells responded to TGF-beta 1 by decreasing basal as well as FK-induced NGF-mRNA levels. Together with previously published work, our results show that cell-type-specific mechanisms not only account for the different control of NGF expression in neurons as compared to glial cells, but also reveal a surprising specificity of regulatory mechanisms in different non-neuronal cell types, even those derived from the same tissue such as fibroblasts and Schwann cells of peripheral nerves.

Animals↗

Repeated elicitation of contact hypersensitivity induces a shift in cutaneous cytokine milieu from a T helper cell type 1 to a T helper cell type 2 profile.

We previously demonstrated that repeated application of 2,4,6-trinitro-1-chlorobenzene resulted in a site-restricted shift in the time course of Ag-specific hypersensitivity responses from a typical delayed-type to an early-type response. Here we demonstrated that the cutaneous microenvironment at the time of Ag presentation to T cells in the elicitation, but not the induction, phase of contact hypersensitivity is responsible for the shift. To investigate the differences in the cutaneous cytokine milieu between the acute and chronic phases of contact hypersensitivity, sequential cytokine dynamics after 2,4,6-trinitro-1-chlorobenzene application were assessed in the acute vs chronic lesions. In the acute lesions, increased mRNA levels for IFN-gamma and IL-2 were rapidly detected at 1 h and remained elevated at 12 h, while mRNA expression for IL-4 and IL-10 was minimally up-regulated between approximately 12 and 24 h. In chronic lesions, high levels of constitutive expression of IL-4 mRNA were observed and IL-10 mRNA was dramatically up-regulated at 1 approximately 3 h in an Ag-specific fashion, whereas the expression of Th1-type cytokines was markedly reduced. Increased mRNA levels for Th2-type cytokines in the chronic lesions was also reflected at the protein level. These results indicate that repeated elicitation with Ag alters the balance of cytokines released locally, with a shift toward Th2-dominated responses, which would represent the natural evolution processes directed toward reducing a more deleterious Th1 response.

Administration, Cutaneous↗

Addition of chemotherapy to radiation therapy alters failure patterns by cell type within non-small cell carcinoma of lung (NSCCL): analysis of radiation therapy oncology group (RTOG) trials.

PURPOSE: To evaluate the influence of cell type within non-small cell carcinoma of lung (NSCCL) on failure patterns when chemotherapy (CT) is combined with radiation therapy (RT). METHODS AND MATERIALS: Data from 4 RTOG studies including 1415 patients treated with RT alone, and 5 RTOG studies including 350 patients also treated with chemotherapy (RT + CT) were analyzed. Patterns of progression were evaluated for squamous cell carcinoma (SQ) (n = 946), adenocarcinoma (AD) (n = 532) and large cell carcinoma (LC) (n = 287). RESULTS: When treated with RT alone, SQ was more likely to progress at the primary site than LC (26% vs. 20%, p = 0.05). AD and LC were more likely to progress in the brain than SQ (20% and 18% vs. 11%, p = 0.0001 and 0.011, respectively). No differences were found in intrathoracic and distant metastasis by cell type. When treated with RT + CT, AD was less likely to progress at the primary than either SQ or LC (23% vs. 34% and 40%, respectively; p = 0.057 and 0.035). AD was more likely than SQ to metastasize to the brain (16% vs. 8%, p = 0.03), and other distant sites (26% vs. 14%,p = 0.019). No differences were found in intrathoracic metastasis. LC progressed at the primary site more often with RT + CT than with RT alone (40% vs. 20%, p = 0.036). Death with no clinical progression was more likely with SQ than AD or LC for RT alone and RT + CT (p < 0.01). Brain metastasis was altered little by the addition of CT, but other distant metastases were significantly decreased (p < 0.001) in all cell types by the addition of CT. CONCLUSION: CT, although effective in reducing distant metastasis in all types of NSCCL, has different effects on the primary tumor by cell type, and has no effect on brain metastasis or death with no progression. Different treatment strategies should be considered for the different cell types to advance progress with RT + CT in NSCCL.

Adenocarcinoma↗

Cell type conversion in a mouse melanoma cell clone.

A melanoma cell clone was isolated from cultured B16 mouse melanoma cells. This clone, conv, which was characterized by rounded and spindle-shaped cell morphology, was not highly melanotic under the usual culture condition but had high tyrosinase (dopa oxidase) activity. When the cells were seeded to form colonies on a plastic culture dish in Eagle's minimum essential medium supplemented with 10% bovine calf serum, two kinds of cell types always appeared. One was cytochemically dopa-positive and spindle-shaped (S type cell) with the same phenotypes as those of the parental cells. The other was dopa-negative and fibroblastlike (F type cell) containing no melanosomes. It was observed that the conversion from S type to F type occurred with a high frequency. The conversion from F type to S type also occurred but with a low frequency.

Animals↗

Short-term sequential analysis of sex hormones and helper T cells type 1 (Th1) and helper T cells type 2 (Th2) cytokines during and after multiple sclerosis relapse.

Multiple sclerosis (MS) is an immune-mediated disease with a clear sex-bias that may be attributed to sex hormones, sex' linked genes or both. Here we sought to determine the evolution pattern of cortisol and sex hormones at MS relapse and 2-months later in 7 male patients with relapsing remitting MS, and whether there was a correlation with a specific Th1 and Th2 cytokine pattern. Our findings indicate the activation of the hypothalamic-pituitary-adrenal axis and the concomitant upregulation of pro- and anti-inflammatory cytokines during relapse. The further increase of sex hormones, in particular estradiol in our male MS patients suggest their possible implication in the physiopathology of the illness and a putative anti-inflammatory and neuroreparatory effect.

Adult↗

Cell-type-specific responses of RT4 neural cell lines to dibutyryl-cAMP: branch determination versus maturation.

This report describes the induction of cell-type-specific maturation, by dibutyryl-cAMP and testololactone, of neuronal and glial properties in a family of cell lines derived from a rat peripheral neurotumor, RT4. This maturation allows further understanding of the process of determination because of the close lineage relationship between the cell types of the RT4 family. The RT4 family is characterized by the spontaneous conversion of one of the cell types, RT4-AC (stem-cell type), to any of three derivative cell types, RT4-B, RT4-D, or RT4-E, with a frequency of about 10(-5). The RT4-AC cells express some properties characteristic of both neuronal and glial cells. Of these neural properties expressed by RT4-AC cells, only the neuronal properties are expressed by the RT4-B and RT4-E cells, and only the glial properties are expressed by the RT4-D cells. This in vitro cell-type conversion of RT4-AC to three derivative cell types is a branch point for the coordinate regulation of several properties and seems to resemble determination in vivo. In our standard culture conditions, several other neuronal and glial properties are not expressed by these cell types. However, addition of dibutyryl-cAMP induces expression of additional properties, in a cell-type-specific manner: formation of long cellular processes in the RT4-B8 and RT4-E5 cell lines and expression of high-affinity uptake of gamma-aminobutyric acid, by a glial-cell-specific mechanism, in the RT4-D6-2 cell line. These new properties are maximally expressed 2-3 days after addition of dibutyryl-cAMP. This indicates that conversion of RT4-AC to the derivative cell types is also a branch point for the regulation of cell-type-specific properties whose expression is responsive to cAMP. Thus, the potential for maturation in response to increased cAMP is a property that segregates in a cell-type-specific manner and is activated at the determinational level in this system.

Autoradiography↗

Cleavage-arrested cell triplets from ascidian embryo differentiate into three cell types depending on cell combination and contact timing.

During early ascidian development, which is a prototype of early vertebrate development, anterior neuroectoderm cells (a4.2) from the eight-cell embryo are destined to become anterior neural structures including the brain vesicle, while presumptive notochordal neural cells (A4.1) become larval posterior neural structures including motoneurons. Whereas, an anterior quadrant cell (A3) of the four-cell embryo, from which both anterior neuroectoderm (a4.2) and notochordal neural cells (A4.1) are derived, has both fates. Cleavage-arrested cell triplets were prepared from the anterior quadrant cell and a pair of anterior neuroectoderm cells (A3-aa triplet) or a pair of presumptive notochordal neural cells (A3-AA triplet), and cultured in contact. Differentiation of cells in the triplet was determined electrophysiologically by observing cell type-specific currents. In the A3-aa triplet, when two neuroectoderm cells and an anterior quadrant cell were prepared from the same batch of embryos, all three cells in the triplet developed into neuronal cells in 60 % of cases, but in 40 % of cases all of them differentiated into epidermal cells. However, when the batch of embryos from which neuroectoderm cells were prepared was fertilized 3 h later than that from which the anterior quadrant cell was prepared all three cells in the triplet consistently became neuronal cells. In contrast, when the batch of embryos from which neuroectoderm cells were prepared was fertilized 3 h earlier, all three cells became epidermal. In the A3-AA triplet no switching of differentiation occurred and all three cells in the triplet differentiated into neuronal cells, although the amplitude of inward current was often small. In neuralized A3-aa triplets the spikes in the anterior quadrant cell were characteristically small in amplitude and brief in duration, suggesting the presence of A-currents, which is a characteristic feature of posterior neuronal differentiation. In contrast, the spikes in the anterior neuroectoderm cells were large in amplitude and long in duration, chracteristic to the anterior neuronal type. The majority of single isolated anterior quadrant cells became non-excitable. However, the minority was apparently autonomously neuralized to become the posterior neuronal type. In neuralized A3-AA triplets, the majority of anterior quadrant cells was induced to become the anterior neuronal type. When isolated anterior quadrant cells were neuralized with subtilisin, a protease, they also predominantly became the anterior neuronal type. While, in medium containing a fibroblast growth factor posterior neuralization of isolated anterior quadrant cells was facilitated, but the anterior neuronal type, although minor, appeared anew. These observations indicate that the multiple fates of the anterior quadrant cell expressed in vivo were effectively reproduced in this experimental condition at the single cell level. Interactive differentiation in this triplet system recapitulates not only fundamental neural induction of ascidian neuroectoderm cells, but also functional and positional specificity within the neuronal group.

Animals↗

A role for distinct cell types in determining malignancy in human neuroblastoma cell lines and tumors.

Human neuroblastoma arises from the developing neural crest. Tumors are categorized clinically by their location, age at diagnosis, spread/metastasis, and degree of cellular maturation and heterogeneity. Our long-term studies have shown the presence in human neuroblastoma cell lines of three distinct cell types: I-type stem cells, N-type neuroblastic/neuroendocrine precursors, and S-type Schwannian/melanoblastic precursors. These distinct cell types can differentiate predictably along specific neural crest lineages in response to particular morphogens. As assessed by tumor formation in nude mice and anchorage-independent growth in soft agar, I-type stem cells are significantly more malignant than either N- or S-type cells. Recent research shows that three similar cell types are also present in human neuroblastoma tumors. Using immunocytochemical, laser-capture microdissection, or short-term culture methods to identify cell types in tumors of different stages and/or different outcomes, these studies have shown that (1) all tumors contain neuroblasts in various differentiation states; (2) presumptive I-type stem cells are present in tumors of all stages; and (3) stromal cells may be tumor-derived, i.e. S-type cells, as well as of normal origin. More importantly, there is a higher incidence of I-type cells in tumors that progress, consistent with the high malignant potential of this cell type in vitro. A better understanding of the cause and consequences of cellular heterogeneity of human neuroblastoma tumors is an important prerequisite to the development of more effective therapies for this often fatal disease.

Animals↗

Tumorigenicity of ten karyotypically distinct cell types present in the human melanoma cell line MeWo-A.

The earliest passage of the human melanoma cell line, MeWo-A, consists of ten cell types that can be distinguished on the basis of chromosome markers. Two of these cell types have chromosomes with long homogeneously staining regions (HSR) containing sequences derived from the short arm of a chromosome #15. In one cell type the HSR is found on a chromosome #15 and in the other it is on a der(15;10)-HSR chromosome. Four other cell types were identifiable by morphologic differences of the short arm of chromosome #13, whereas, the four remaining cell types were identifiable by the presence of prominent satellites on other chromosomes. This study was directed at assessing the relative tumorigenic properties of the different cell types by injecting different numbers of cells intraperitoneally, subcutaneously, or intravenously into Balb/c nude mice. The primary tumors and nodules that developed in the peritoneal cavity and lungs were explanted into tissue culture. One hundred metaphase chromosome spreads from each established cell line were analyzed cytogenetically to detect changes in proportions of the different cell types. The cell type containing the der(15;10)-HSR chromosome was present in only 20% of the cells injected, but increased in proportion to between 28% and 98% after growth in nude mice. Although the degree of selection of the der(15;10)-HSR-containing cell type was influenced by the number of cells injected, the consistent selection of these cells strongly suggests that this cell type has a growth advantage. Because the 15-HSR-containing cell type rarely increased in proportion, it is likely that the HSR by itself can not confer the enhanced tumorigenic phenotype but requires the expression of other sequences present on other MeWo chromosomes to provide the selective growth advantage to the cells in which it is found.

Animals↗

Discrimination of cell types in primary transitional cell carcinoma by monoclonal anti-cytokeratin antibodies.

The morphologic discrimination between low and high grade malignant tumor cells arising in the urinary bladder is a major diagnostic problem in cytopathology. Using immunochemical peroxidase staining of cytokeratins (CKs) of human bladder exfoliative cytology specimens, we have been able to discriminate between transitional cell carcinoma cells, atypical cells and normal bladder cells. Commercially available monoclonal antibodies used in this study were: anti-CK 13 (Sigma K8.12), anti-CK 5, 7 and 8 (Sigma K8.13), anti-CK 19 (Sigma K4.62), and anti-CK 18 (Transformation Res. 1091). When normal bladder cells are stained with these antibodies, CK 18 is specific for superficial cells; CK 13 is specific for the basal type cells and CKs 5, 7, 8 and 19 are expressed by all urothelial cell types. Four cases diagnosed by cytopathological criteria as 'atypical' and 7 diagnosed as 'positive' (various grades) were used in this study. Cytologic diagnosis was confirmed by histopathology in 7 cases. Tissue was not available for histopathology in 4 cases. Malignant cells with a 'basal' or 'immature' phenotype preferentially stained with CK 13 and were associated with increased metastatic or malignant potential. Patients with higher grade tumors had more cells positive for CK 13 than did patients with atypical or lower grade malignancies. Patients with well-differentiated, low grade tumors predominantly shed cells that expressed CK 18 and CK 19. High grade, invasive bladder lesions were characterized by many cells expressing CK 13, and fewer cells expressing CK 19. The combination of diagnosis by morphologic criteria on Papanicolaou-stained specimens with immunochemical characterization of the same cells for CKs facilitate an accurate diagnosis of bladder lesions.

Adult↗

scATAnno: Automated Cell Type Annotation for Single-cell ATAC-seq Data.

Recent advances in single-cell epigenomic techniques have increased the demand for single-cell assay for transposase-accessible chromatin using sequencing (scATAC-seq) analysis. One key analytical task is to determine cell type identity based on epigenetic data. Here, we introduce scATAnno, a Python package designed to automatically annotate scATAC-seq data using large-scale scATAC-seq reference atlases. This workflow generates reference atlases from publicly available datasets, enabling accurate cell type annotation by integrating query data with reference atlases without the use of single-cell RNA sequencing (scRNA-seq) data. To enhance annotation accuracy, we incorporated k-nearest neighbors (KNN)-based and weighted distance-based uncertainty scores to effectively detect cell populations within the query data that are distinct from all cell types in the reference data. We compared and benchmarked scATAnno against five other published cell annotation approaches, demonstrating its superior performance across multiple datasets and metrics. We further showcased the utility of scATAnno across multiple datasets, including peripheral blood mononuclear cells (PBMCs), triple-negative breast cancer (TNBC), and basal cell carcinoma (BCC), and demonstrated that scATAnno accurately annotates cell types across diverse biological conditions. Overall, scATAnno is a useful tool for scATAC-seq reference atlas construction and cell type annotation and can facilitate the interpretation of new scATAC-seq datasets in complex biological systems. scATAnno is publicly available at https://scatanno-main.readthedocs.io/.

Single-Cell Analysis↗

[Polyvalent hyperimmune immunoglobulins prevent the infection of monocytic type cells by human cytomegalovirus].

Monocyte/macrophage cell types can be infected with Human Cytomegalovirus (HCMV) could be a reservoir and a vehicle for virus spread in infected patients. We developed a model to study the effects of antiviral molecules on these cells. The monocytic-like cell line THP-1 and the human diploïd cells MRC-5 were used. THP-1 cells were cultivated with a phorbol 12-myristate 13-acetate (PMA) for 24h prior to the infection. We studied infection of these cells with reference strain (AD-169). A cell free virus suspension of HCMV was preincubated with hyperimmune polyvalent immunoglobulins. The infection of the cells was studied on the basis of immune detection of viral immediate early antigens (IEA) in nucleus 24h after culture. Our results showed that hyperimmune polyvalent immunoglobulins have been able to neutralize fibroblasts and THP-1 cells infection, whereas control antibodies did not inhibit the infection of the cells. This is the first report of the use of monocytic-like cells for testing the efficiency of anti-CMV molecules.

Antigens, Viral↗

Identification and estimation of cell types in mixed primary cell cultures of early and term human placenta.

Placental villi of early and term human placentae were dissociated with trypsin and mixed cell cultures were established. The different cell types were identified and estimated over a 14-day culture period using antibodies to keratin and vimentin filaments and their capacity to phagocytose yeast. The three main cell types were found to be epithelial-, macrophage- and fibroblast-like cells. The epithelial-like cells can be further divided into the multinucleated and the small- and medium-sized round cells, and these are most likely to be derived from the trophoblast. The cellular composition of cultures were different for early and term placentae and also varied characteristically over the 14-day cultures period.

Antibodies↗

Delineation of four cell types comprising the giant cell tumor of bone. Expression of Ia and monocyte-macrophage lineage antigens.

Giant cell tumors of bone dissociated by collagenase digestion were found to be composed of four different cell types defined by morphology, growth in culture, and pattern of staining with monoclonal antibodies. Giant cells comprised an average of 0.8% of the cells recovered, with the remainder consisting of small stromal cells. Of the giant cells, 20-57% expressed Ia antigens, while all lacked IgG Fc receptors and five differentiation antigens associated with mature members of the monocyte-macrophage lineage (M phi S-1, M phi P-9, M phi P-15, M phi S-39, and 63d3). One antigen, M phi U-50, found on early monocytoid forms was expressed on Ia+ giant cells. 6-36% of the remaining stromal tumor cells formed a second subpopulation that assumed either a rounded or elongated shape in culture. These cells bore Ia antigens, IgG Fc receptors, and five antigens of the monocyte-macrophage lineage usually found on blood monocytes. However, these cells differed from monocytes or macrophages in that the antigen M phi R-17 generally found on tissue macrophages was absent, and the M phi U-50 antigen present on more primitive cells was well expressed. A very limited endocytic capacity was demonstrable. A third population of up to 24% of the tumor cells was defined by the presence of intense staining for Ia antigens but the absence of antigens of mature monocytes. A proportion of these cells expressed M phi U-50 and a minority had IgG Fc receptors. The two Ia(+) populations of stromal cells were not identifiable after 2 wk of culture, nor did tumor cells selected for the presence of Ia antigens proliferate in culture. A fourth population of cells lacked Ia and monocyte lineage antigens, but showed pronounced intracellular staining for acid phosphatase. These cells had a distinctive plump epitheloid to fibroblastoid morphology and were readily established in long-term culture where they gave rise to large multinuclear Ia(-) cells containing acid phosphatase. The possibility is discussed that the cell types of these tumors relate to various stages in the development of osteoclasts from precursors in the mononuclear phagocyte lineage.

Acid Phosphatase↗

Expression of oestrogen receptor beta (ER beta) occurs in multiple cell types, including some germ cells, in the rat testis.

The identification of a second oestrogen receptor (beta) has prompted a re-evaluation of the potential sites of action of oestrogens. The aim of the present study was to characterize immunoexpression of ER beta expression in the testis to complement earlier data which had demonstrated that expression of ER alpha is confined to testicular interstitial Leydig cells. In all testes studied, including those from both fetal (day 20.5 p.c.) and adult rats, ER beta was found to be expressed in multiple cell types. Sertoli cell nuclei were immunopositive at all ages. In adult testes expression in Sertoli cells was not stage dependent and was unaffected by ablation of Leydig cells. In fetal testes ER beta was also expressed in peritubular cells, fetal Leydig cells and gonocytes. In the pubertal and adult testis ER beta was detected in the nuclei of spermatogonia and most pachytene spermatocytes. Weak immunopositive staining was present in the cytoplasm of spermatocytes undergoing the second meiotic division. In conclusion the widespread expression of ER beta in the testis is consistent with a role for oestrogens in modulating spermatogenesis, and hence fertility, in the male.

Animals↗