Dendritic cells with antigen-presenting capability reside in airway epithelium, lung parenchyma, and visceral pleura.

In this study, we identified a population of dendritic cells (DC) that exists throughout human and mouse pulmonary tissues, including the trachea, bronchi, alveoli, and visceral pleura. In human tissue, these DC were shown to be positive for HLA-DR and T200 antigens. In the mouse, the DC expressed not only Ia and the T200 antigen, but also Fc-IgG and C3bi receptors. Unlike alveolar macrophages, the DC were negative for nonspecific esterase staining and shared ultrastructural similarities with the DC described by Steinman (1), and with Langerhans' cells, even though they did not contain Birbeck granules. We were able to demonstrate that mouse pulmonary DC function in antigen presentation, as observed with the other DC. Thus, the respiratory tract contains DC that are capable of functioning in antigen presentation and that may be important in pulmonary immune responses.

Sialic acids on the plasma membrane of cultured human lymphoid cells. Chemical aspects and biosynthesis.

From 61 to 92% of the total sialic acid of a variety of human lymphoid cell lines maintained in tissue culture is present on the cell surface as measured by its susceptibility to cleavage by Clostridium perfringens neuraminidase. These cells contain from 1.22 x 10(8) to 6.99 x 10(8) molecules of surface sialic acid per cell. In synchronized cultures synthesis of surface sialic acid occurs only during a limited time in the late G(2) phase of the cell cycle. The amount and density of surface sialic acid vary considerably throughout the cell cycle.

A neuroendocrine marker in tissues of the immune system.

Antibodies to chromogranin, a secretory protein marker for the diffuse neuroendocrine system, were used to analyze rat lymphoreticular tissues by means of immunochemistry and immunohistochemistry. Chromogranin-positive cells were present in spleen, lymph node, thymus, and fetal liver. When these organs were gently dispersed and separated on a Ficoll gradient, the chromogranin-immunoreactive cells became enriched in the dense red-cell pellets. The unexpected distribution of these neuroendocrine cells in all immunologically relevant structures suggests that they may link the nervous and immunological systems.

Lymphocyte DNA synthesis inhibition.

A specific endogenous inhibitor for lymphocyte DNA synthesis that can be isolated from the lymphoid system and which is probably cell specific is described. The inhibitor is thermolabile, is destroyed by trypsin, and has a mass of about 30,000 to 50,000 daltons.

Immunoreactive apolipoprotein E is a widely distributed cellular protein. Immunohistochemical localization of apolipoprotein E in baboon tissues.

Apolipoprotein (apo)E is an important protein determinant in cholesterol homeostasis in man. The protein is synthesized by the liver as well as by a number of extrahepatic tissues. In the present study, immunohistochemical techniques were used to identify apoE in specific cells in various baboon organs. In the 11 tissues studied, the following cell types have been found to harbor apoE immunoreactivity: cerebral astrocytes; thyroid follicular cells; alveolar type II pneumocytes; hepatocytes, and Kupffer cells; adrenocortical cells in zona fasciculata and zona reticularis; adrenal medullary cells; some renal tubular epithelia; some pancreatic islet cells; histiocytic macrophages in lymph nodes and the spleen; some gastric mucosal epithelia; and ovarian oocytes. These observations indicate the wide distribution of apoE in many organs and suggest that the protein might perform other important functions such as regulation of local hormonal homeostasis in addition to its role in cholesterol metabolism.

Glucocorticoid receptors and steroid sensitivity in normal and neoplastic human lymphoid tissues: a review.

The determination of estrogen and progesterone receptors in breast cancer has been shown to be useful in predicting the response to endocrine therapy. Given their well-known inhibitory effects on lymphoid tissue, glucocorticoids have been used widely in the treatment of leukemia. Given these facts, over the last 10 years, several investigators have measured the number of glucocorticoid receptors in normal and neoplastic lymphoid tissue to see whether their number correlated with glucocorticoid responsiveness in vitro or in vivo. No clear correlation could be established between the level of glucocorticoid receptor and the in vitro action of steroids in normal and neoplastic lymphoid tissue. In contrast, attempts to correlate glucocorticoid receptor levels in acute lymphocytic leukemia to in vivo steroid responsiveness and immunological type using the whole-cell-binding assay for receptor determination and selecting the patients according to age and immunological criteria have been more successful.

Major proteins induced and down-regulated by interferons in human cultured cells: identification of a unique set of proteins induced by interferon-alpha in epithelial, fibroblast, and lymphoid cells.

In all, 40 major polypeptides ranging in molecular weights from 14.5 to 83 kDa were shown to be induced by IFNs alpha (also by IFN-alpha 2b and beta in a few cases) and gamma in human cultured cells of epithelial (transformed amnion cells (AMA)), fibroblast (proliferating and quiescent MRC-5 fibroblasts), and lymphoid origin (Molt-4). With the exception of a heat shock protein (IEF14 or hs x 70) and two tropomyosins (IEFs 52x and 55), none of these proteins corresponded to polypeptides (proliferation-sensitive or others) previously identified and catalogued by us. IFN-alpha induced the highest number of polypeptides in lymphoid cells, while the response to IFN-gamma was more pronounced in cultured epithelial and fibroblast cells. Several of the polypeptides induced by IFNs alpha and gamma were synthesized (albeit at different rates) by the control untreated cells, and in some cell types such as normal human peripheral blood mononuclear cells many were expressed at high levels. Only IFN-alpha-induced a unique set of proteins (alpha 1, 51 kDa; alpha 2, 15 kDa; alpha 19, 78 kDa; and gamma 10, 83 kDa) in all cultured cell types studied, implying that response to this IFN involves a shared biochemical pathway(s). Both IFN-alpha (also IFN-alpha 2b) and beta induced an identical group of proteins in AMA cells in agreement with the fact that type I IFNs share common receptors. IFNs alpha and gamma induced a few common polypeptides, but only gamma 10 (83 kDa) showed increased synthesis in all cell types exposed to either of these IFNs. A total of 28 major cellular polypeptides were down-regulated by IFNs in the various cell type studied. Different sets of proteins were affected, however, in each system, emphasizing the complexity of the mechanisms underlying the action of these factors. Treatment of synchronized G1 AMA cells with IFNs alpha, beta, or gamma (500 IU/ml, final concentration) did not inhibit their progression from G1 to S-phase as determined by indirect immunofluorescence using PCNA autoantibodies specific for cyclin. These observations were in line with the fact that IFNs did not affect dividin or cyclin(PCNA) synthesis (S-phase specific proteins) at least within the first 17 hr after their addition.

The effects of fixative type and fixation time on the quantity and quality of extractable DNA for hybridization studies on lymphoid tissue.

Encouraged by recent reports of extraction of diagnostically useful DNA from formalin-fixed tissues, we devised a study to determine which fixatives are suitable for DNA hybridization studies. Seven lymph node specimens (6 lymphomas and one reactive hyperplasia) were studied. Specimens were divided into portions, each of which was processed separately. Processing protocols followed were: 1) snap freezing; 2) immersion in formalin, ethanol, glutaraldehyde, B5 and methanol acetic acid (MAA) Michel's transport medium or phosphate buffered saline for 2, 24, 48 and 120 hrs.; 3) paraffin embedding following fixation. DNA was obtained by proteinase K digestion followed by phenolchloroform extraction. DNA was cleaved with restriction endonucleases (Eco RI and Bam HI), separated by agarose gel electrophoresis, after which Southern blot hybridization with radio-labelled probes for J-heavy and T-beta genes was performed. Fixation with formalin, glutaraldehyde and B5 resulted in poor yields of DNA. MAA produced degradation of DNA and Michel's medium and PBS gave low quantities and purity of extracted DNA. Ethanol fixation consistently permitted extraction of large amounts of high molecular weight DNA suitable for hybridization studies and compared favourably with the fresh-frozen 'gold standard'. We conclude that ethanol may be the fixative of choice when transport or storage conditions limit the availability of fresh frozen tissue for DNA hybridization studies.

Improved detection of aneuploidy in malignant melanoma using multiparameter flow cytometry for S100 protein and DNA content.

DNA aneuploidy has been demonstrated to be an independent parameter of prognostic significance in malignant melanomas. In order to improve the detection of DNA aneuploidy in malignant melanomas, and to minimize diploid non-tumor cells in the sample, we developed a two-color staining strategy for S100 protein and DNA content in paraffin embedded samples. The ability to detect aneuploidy, defined as DNA ploidy index less than or equal to 0.90 or greater than or equal to 1.10, in 37 stage I malignant melanoma samples by flow cytometry analysis was significantly improved from 10.8% of cases using traditional one-color analysis for DNA content only (propidium iodide) to 32.4% of cases using two-color analysis for simultaneous measurement of both DNA (propidium iodide) and S100 protein (fluorescein conjugated antibody) (Chi-square with Yates' correction; p less than 0.05). The largest increase in sensitivity was found in level I and II melanomas less than or equal to 0.76 mm in thickness. In addition, we report the new observation that multiple S100 protein-positive subpopulations were found significantly more frequently in malignant melanomas (23/37 cases) than in compound melanocytic nevi (5/22 cases) (Chi-square with Yates' correction; p less than 0.01). These findings suggest that there is a previously unsuspected degree of tumor heterogeneity even in thin, presumably early, malignant melanomas.

Application of image analysis for quantitative immunoperoxidase detection of IgE containing cells in lymphoid tissues.

Methods for the quantitation of antigen or antibody specific cells within lymphoid structures rely on the laborious and often inaccurate counting of stained cells visually under the microscope. To circumvent these problems we used a combination of computer-linked image analysis, with the Quantimet 720 and specific staining for IgE by immunoperoxidase, to produce a relatively easy, accurate method for the quantitation of specifically stained cells within tonsils and lymph nodes. Frozen sections of bovine lymph nodes and tonsils were stained in an indirect immunoperoxidase technique with either rabbit anti-bovine IgE or normal rabbit serum as the primary reagent. Examination of the stained slides on the Quantimet 720 image analyzing computer revealed cells that were sufficiently dark to be considered above the 'threshold level' of background staining. These were counted as positive picture points. A quantitative evaluation of the relative number of IgE containing cells within the particular lymphoid tissue was arrived at by determining the difference between the percent positive picture in the control tissue incubated with normal rabbit serum (background) and in the sample treated with rabbit anti-IgE. Using this method, it was readily possible to quantitate the presence of IgE containing cells in the tonsils of calves; the highest percentage of positive tissue was present in the tonsils of calves exposed to ovalbumin. Image analysis is a useful technique for quantitative evaluation of any immunoperoxidase stained tissues.

Recognition of two epitopes of an antigen present on canine T cells but not on hemopoietic progenitors by four monoclonal antibodies.

Pairs of murine monoclonal antibodies, which recognize 2 different epitopes on a single antigen are described. These antibodies (MdT-P1, -P2, -Q1, -Q2) defining a canine pan-T cell antigen, were raised against dog thymocytes. In immunoblotting of solubilized and polyacrylamide gradient gel electrophoresis in sodium dodecyl sulphate (SDS-PAGE) fractionated dog thymocytes, they revealed a strong heterogeneous antigen. Competitive inhibition of binding of directly labeled mouse-antidog T lymphocytes monoclonal antibodies (MdT-mAbs) to solubilized dog thymocytes indicates that 2 different antigenic epitopes (P, Q) are recognized. In indirect peroxidase immunocytochemistry, MdT monoclonal antibodies recognized up to 95% thymocytes, 69% blood lymphocytes, 76% lymph node lymphocytes, and approximately 2% bone marrow lymphocytes; they were nonreactive with surface immunoglobulin positive blood cells, monocytes, platelets, cells of myelo- and erythropoietic lineage in the bone marrow. Immunohistochemistry on thymus, lymph nodes, and spleen sections revealed that MdT-mAbs had labeled cortical and medullary thymocytes, paracortical T cell areas in lymph nodes and the periarteriolar zone of spleen white pulp, whereas B cell areas remained unstained. The antibodies lysed dog thymocytes in the presence of complement. Lethally irradiated dog receiving bone marrow autograft depleted of MdT-P1 positive cells ex vivo showed engraftment and complete recovery of marrow function. Studies of antibody activity on canine hemopoietic progenitor cells in granulocyte-macrophage progenitors (CFUGM) also showed no reduction of CFUGM in MdT-P1-depleted bone marrow.

Occurrence and distribution of glycoconjugates in human tissues as detected by the Erythrina cristagalli lectin.

We applied a horseradish peroxidase-Erythrina cristagalli agglutinin (HRP-ECA) conjugate for histochemical staining of tissue sections from various formalin-fixed, paraffin-embedded human tissue specimens. The HRP-ECA conjugate showed broad reactivity, but there was a distinct distribution of native (not masked by sialic acid) and sialic acid-masked ECA binding sites in the various organs. Free ECA binding sites could be detected on red blood cells, lymphocytes of thymus, tonsil, lymph node, and in mucous substances of different organs. Independent of blood group type, the vascular endothelium exhibited strong ECA reactivity. Free ECA binding sites occurred in the cytoplasm of Kupffer's cells in liver, in histiocytic cells of thymus, lymph node, tonsil, and in bone marrow. Podocytes of kidney glomerulus, syncytiotrophoblasts of placenta, megakaryocytes in bone marrow, myelin sheath of nerve, medullary thymocytes, and hepatocytes, as well as islet cells of pancreas, contained only sialic acid-capped ECA binding sites. Inhibiting studies with galactose, lactose, and N-acetyl-lactosamine, as well as other sugars, revealed that this lectin is specific for galactosyl residues. In comparison to galactose and lactose, N-acetyl-lactosamine exhibited the highest inhibitory activity on lectin binding, supporting the concept that this lectin is most reactive with N-acetyl-lactosamine-type (type 2 chain) glycoconjugates.

Extracellular matrix of lymphoid tissues in the chick.

We describe the immunohistochemical distribution of components of the extracellular matrix of the chick lymphoid system. In the thymus, basement membranes of epithelial cells bordering the lobules were intensely stained by laminin antibodies; fibronectin antibodies labeled the capsule and the septal matrix, and similar reactivity was seen with tropoelastin and gp 115 antibodies. No positivity was detected with any of the antibodies within the cortical parenchymal cells. Laminin was not detected in the medullary parenchyma, whereas fibronectin was present as coarse fibers. Tropoelastin and gp 115 appeared as a finer and more diffuse meshwork. In the bursa, laminin antibodies outlined the epithelial cells separating the cortex from the medulla. Fibronectin, tropoelastin, and gp 115 antibody stained the interfollicular septa and the cortical matrix, although to a different extent. Laminin was also detected in association with the interfollicular epithelium (IFE) basement membrane, whereas no staining was found underneath the follicle-associated epithelium (FAE). FAE cells not only lack a proper basement membrane but are also not separated from medullary lymphocytes by any of the other extracellular matrix components were investigated. Consequently, medullary lymphocytes are not sequestered, and can come easily into contact with antigens present in the intestinal lumen. All four antibodies stained the spleen capsule and spleen blood vessels, tropoelastin and gp 115 antibodies giving the strongest reactivity. A fine trabecular staining pattern was detected with gp 115 antibodies in the white pulp.

Immunohistochemical analysis of nerve growth factor receptor expression in normal and malignant human tissues.

Nerve growth factor (NGF) is a polypeptide important for normal development of the nervous system and promotion of survival and differentiation of sensory and sympathetic neurons in culture. The cellular effects of NGF are mediated by a specific cell surface molecule, nerve growth factor receptor (NGF-R). In the present study we have used a monoclonal antibody against human NGF-R to examine, by the avidin-biotin-immunoperoxidase method, the receptor distribution in a wide range of normal tissues and in more than 200 malignant tumors. Our results show that (a) human NGF-R is expressed in the peripheral nervous system but not in any of the central nervous system areas tested; (b) NGF-R expression is not restricted to neural tissues but is also found in a number of normal epithelial, mesenchymal, and lymphoid tissues; (c) NGF-R expression changes during normal development; and (d) NGF-R expression in malignant tumors generally parallels its normal tissue distribution. Thus, NGF-R is detected in a proportion of neuroectoderm-derived tumors, carcinomas, and lymphomas, and also in a characteristic group of small round-cell tumors (Ewing's sarcomas and embryonal rhabdomyosarcomas). These findings suggest a normal regulatory role for NGF in both neuronal and non-neuronal cells and identify a range of human tumors in which the NGF/NGF-R system may contribute to the malignant phenotype.

Double immunocytochemical labeling of cell and tissue samples with monoclonal anti-bromodeoxyuridine.

We describe a new monoclonal antibody (designated Bu20a) against bromodeoxyuridine (BrdU). This antibody was selected by screening against human tissues using the APAAP technique, and shows no crossreactivity with normal nuclei. It stains BrdU incorporated into the nuclei of a wide range of cell types, including human tonsil lymphoid cells, normal mouse tissues, and human tumors growing in nude mice. A double-labeling technique is described using this antibody in which cell smears or tissue sections are first labeled by an immunoperoxidase procedure for a cellular antigen (e.g., mouse or human histocompatibility class II antigen, T-lymphocyte antigen, keratin) and BrdU is then detected by indirect immunofluorescence. This procedure, which was applied to a variety of human and animal cells and tissues, is of wide potential value in analyzing the phenotype of S-phase cells and in co-localizing antigen expression and BrdU incorporation in tissue sections.

Fc and complement receptor lymphocytes in the ocular tissues of rabbits immunized intravitreally with ovalbumin.

The numbers of antibody producing cells (PFC) and the percentages of Fc receptor cells (FcR) and complement receptor cells (CRL) in the ocular and lymphoid tissues of rabbits immunized intravitreally with ovalbumin were determined. Antibody-producing cells were detected first in the lymph nodes and then in the uveas and corneas. The uveal tracts contained more than 50% FcR early in the antibody response, but the percentages returned to normal levels during the second postinjection week. An apparent inverse relationship between the numbers of ocular PFC and the percentages of ocular FcR was noted. The percentages of CRL in the spleens and lymph nodes were similar to those reported by other investigators. No obvious correlation between CRL percentages in the ocular tissues and the numbers of PFC was seen. The "T-" or "B-" cell nature of the ocular FcR and their possible functions in regulating ocular immune responses are yet to be determined.

Immunocytochemical localization of vitamin D-dependent calcium-binding protein in the growing chick lymphoid organs.

Monospecific antiserum against chick duodenal vitamin D-dependent calcium-binding protein (D-CaBP) was used to localize this protein by the peroxidase-antiperoxidase method (PAP) in the thymus, spleen and bursa of Fabricius of normal growing chicks in 20 day old embryos; in normal growing chicks at 1, 2, 3, 4 and 6 weeks of age in chicks fed a rachitogenic diet for 4 weeks. In the normal chick thymus, D-CaBP was localized throughout the cytoplasm and in the nucleus of cortical epithelial reticular cells (ERC) and in Hassal's corpuscles of the medulla. In the normal spleen reticular cells of the marginal zones showed dense deposition of reaction product in the nucleus and throughout the cytoplasm. In the bursa of Fabricius, only a few scattered cells in the medulla showed some staining. Wide variation was encountered in D-CaBP staining in the thymus and spleen of 4 week old chicks from different broods. In 4 week old rachitic chicks, staining in the thymus and in the spleen was generally reduced in intensity and occasionally was entirely absent. The presence of D-CaBP in some reticular cells of the thymus, spleen and bursa of Fabricius, identifies these lymphoid organs as vitamin D3 targets. Thus, 1,25(OH)2D3 may have an important role in some aspects of the immune defence mechanism.

Studies on the chemical nature of dialysable transfer factor. Comparison of human leukocyte dialysate and dialysates derived from human serum and from mammalian lymphoid and non-lymphoid organs.

The chemical nature of human dialysable transfer factor (TFd), capable of augmenting delayed hypersensitivity (DH) in human recipients, and some mammalian organ dialysates, known to augment DH in antigen-primed guinea pigs, were compared using chromatography on Sephadex G-10 and G-25 columns and on thin-layer plates. The fractions of human leukocyte dialysate which eluted at or after the Vt of the Sephadex columns have previously been shown to contain the in vivo TFd-activity and therefore special attention was paid to corresponding dialysate fractions. All together 52 identified or unidentified components were found at or close to this elution region with thin-layer chromatography (TLC). The 14 identified substances were nucleobases, nucleosides, sugars and aromatic or heterocyclic amino acids. Unidentified components had similar staining characteristics as the identified ones on TLC. No evidence was found for the presence of peptides or nucleotides. There were no components specific for human leukocyte dialysate. Several of the identified and unidentified substances in fractions of humal dialysable leukocyte extract were common to all or nearly all dialysates. The possibility that some of the unidentified components might be responsible for the in vivo effect of human leukocyte dialysate in man or guinea pig is discussed.

Use of imprints for monoclonal antibody studies: suitability of air-dried preparations from lymphoid tissues with an immunohistochemical method.

Air-dried imprint preparations are conveniently produced from human lymphoid samples without the special methods required for snap-freezing tissues or rendering them into suspensions. T-cells, T-cell subsets (helper and suppressor), and HLA-DR-positive cells (B-lymphocytes, monocytic-histiocytic cells) can be identified in such imprints by the use of commercially obtained mouse hybridoma antibodies with a simple two-step immunoperoxidase method. Direct nuclear morphologic correlation with surface determinants is achieved by this method. Immunoreactivity is retained only eight to 10 days in such air-dried preparations, and attempts to prolong reactivity have been unsuccessful so far.

Significance of S-100 protein immunostaining in the immunohistological analysis of normal and neoplastic lymphoid tissues--an appraisal.

S-100 protein is a heterogeneous fraction of dimeric polypeptides (alpha and beta subunits) that can exist in different combination forms within the various tissues. Concerning the S-100 protein immunodetection within lymphoid tissue, the heterogeneity of the S-100 antigen, the tissue quality (frozen or paraffin-embedded after treatment with different fixatives) and the treatment of the tissue with different immunostaining methods and antibodies of different nature, all make for inconsistent results obtained in the immunohistological studies reported in the literature. Most of the S-100-positive cells of the lymphoreticular system are dendritic cells involved in the immune response (interdigitating reticulum cells, Langerhans cells, and follicular dendritic reticulum cells), other S-100-positive cells belonging to the mononuclear/phagocytic system. S-100 protein immunostaining may be used as a helpful immunohistological diagnostic clue to certain malignancies of the immune system (follicular center cell lymphomas) on the basis of their specifically related dendritic cell microenvironment. In addition to monoclonal antibodies for the immunophenotypic characterization of dendritic cells and macrophages and to enzyme reactions, the combined use of anti-S-100 antibodies specific for each of the S-100 protein subunits, tested with sensitive procedures, would be a very useful tool in the attempt to classify the proliferative disorders of dendritic cells and macrophages.