Different surface glycoprotein patterns on human T-, B- and leukemic-lymphocytes

CPHEN-011: Comprehensive phenotyping of murine lung resident lymphocytes after recovery from pneumococcal pneumonia

Recovery from pneumococcal (Spn) pneumonia induces development of tissue resident memory CD4+ TRM cells, BRM cells, and antibody secreting plasma cells in experienced lungs. These tissue resident lymphocytes confer protection against subsequent lethal challenge by serotype mismatched Spn (termed as heterotypic immunity). While traditional flow cytometry and gating strategies support premeditated identification of cells using a limited set of markers, discovery of novel tissue resident lymphocytes necessitates stable platforms that can handle larger sets of phenotypic markers and lends itself to unbiased clustering approaches. In this report, we leverage the power of full spectrum flow cytometry (FSFC) to develop a comprehensive panel of phenotypic markers that allows identification of multiple subsets of tissue resident lymphocytes in Spn-experienced murine lungs. Using Phenograph algorithm on this multidimensional data, we identify unforeseen heterogeneity in lung resident adaptive immune landscape which includes unexpected subsets of TRM and BRM cells. Further, using conventional gating strategy informed by our unsupervised clustering data, we confirm their presence exquisitely in Spn-experienced lungs as potentially relevant to heterotypic immunity and define CD73 as a highly expressed marker on TRM cells. Thus, our study emphasizes the utility of FSFC for confirmatory and discovery studies relating to tissue resident adaptive immunity.

Inhibition of Leukocyte Migration by a Human Colon Cancer Extract

The direct leucocyte migration inhibition test in capillary tubes was used to test 10 patients with colonic adenocarcinoma against KCl soluble extracts of an allogenic colon cancer and an allogenic normal colon fragment. Inhibition was consistently found with the cancer extract but not with the normal tissue extract. None of the control group of patients affected by other tumors, intestinal and liver disorders showed a migration inhibition in response to the colonic tumor extract. Our findings strongly suggest the presence of a tumor-associated antigen in the cancer extract.

From genome to proteome: Looking beyond DNA and RNA in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) remains the most common leukemia in the Western world. Whilst its disease course is extremely heterogeneous (ranging from indolent to aggressive), current methods are unable to accurately predict the clinical journey of each patient. There is clearly a pressing need for both improved prognostication and treatment options for patients with this disease. Whilst molecular studies have analyzed both genetic mutations and gene expression profiles of these malignant B-cells, and as a result have shed light on the pathogenesis of CLL, proteomic studies have been largely overlooked to date. This review summarizes our current knowledge of the proteomics of CLL, and discusses some of the issues in CLL proteomic research, such as reproducibility and data interpretation. In addition, we look ahead to how proteomics may significantly help in the development of a successful treatment for this currently incurable disease.

A unique proteomic profile on surface IgM ligation in unmutated chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by a highly variable clinical course with 2 extreme subsets: indolent, ZAP70(-) and mutated immunoglobulin heavy chain gene (M-CLL); and aggressive, ZAP70(+) and unmutated immunoglobulin heavy chain (UM-CLL). Given the long-term suspicion of antigenic stimulation as a primum movens in the disease, the role of the B-cell receptor has been extensively studied in various experimental settings; albeit scarcely in a comparative dynamic proteomic approach. Here we use a quantitative 2-dimensional fluorescence difference gel electrophoresis technology to compare 48 proteomic profiles of the 2 CLL subsets before and after anti-IgM ligation. Differentially expressed proteins were subsequently identified by mass spectrometry. We show that unstimulated M- and UM-CLL cells display distinct proteomic profiles. Furthermore, anti-IgM stimulation induces a specific proteomic response, more pronounced in the more aggressive CLL. Statistical analyses demonstrate several significant protein variations according to stimulation conditions. Finally, we identify an intermediate form of M-CLL cells, with an indolent profile (ZAP70(-)) but sharing aggressive proteomic profiles alike UM-CLL cells. Collectively, this first quantitative and dynamic proteome analysis of CLL further dissects the complex molecular pathway after B-cell receptor stimulation and depicts distinct proteomic profiles, which could lead to novel molecular stratification of the disease.

ICAM-5--a novel two-facetted adhesion molecule in the mammalian brain

Cell adhesion is of utmost importance for normal development and cellular functions. ICAM-5 (intercellular adhesion molecule-5, telencephalin) is a member of the ICAM-family of adhesion proteins. These proteins bind to leukocyte beta(2)-integrins (CD11/CD18), but ICAM-5 is exceptional in several ways. It is solely expressed in the mammalian forebrain, appears at the time of birth, and is located in the soma and dendrites of neurons. It is structurally more complex than the others, and also shows homophilic adhesion. Recent studies show that it is important for the regulation of immunological activity in the brain and for the development of neuronal synapses and signal transmission.

Protein expression profiling of CLL B cells using replicate off-line strong cation exchange chromatography and LC–MS/MS

In this study we use replicate 2D-LC-MS/MS analyses of crude membranes from B cells derived from a patient with chronic lymphocytic leukemia (CLL) to examine the protein expression profile of CLL B cells. Protein identifications made by replicate 2D-LC-MS/MS analysis of tryptic peptides from detergent solubilized B cell membrane proteins, as well as replicate LC-MS/MS analysis of single off-line strong cation exchange chromatography (SCX) fractions, were analyzed. We show that despite the variance in SCX, capillary LC, and the data-dependent selection of precursor ions, an overlap of 64% between proteins identified in replicate runs was achieved for this system.

Leucocyte common antigen is present on osteoclasts

Using a large panel of monoclonal antibodies which recognize the leucocyte common antigen (LCA), the presence of LCA on osteoclasts in both fetal and adult human bone specimens has been determined by immunohistochemistry. LCA is evident on the surface of fetal human osteoclasts in bone imprints and cryostat sections. LCA was also found on osteoclasts in specimens of fixed, decalcified osteoarthritic bone. The intensity and pattern of osteoclast reactivity were similar to those of foreign-body type macrophage polykaryons in inflammatory lesions. These results favour derivation of osteoclasts and their precursors from the multipotential haemopoietic stem cell which produces peripheral blood leucocytes and argues against their origin from a separate stem cell.

Leukocyte common antigen--a diagnostic discriminant between hematopoietic and nonhematopoietic neoplasms in paraffin sections using monoclonal antibodies: correlation with immunologic studies and ultrastructural localization

Immunohistochemical localization of human leukocyte common antigen (LCA), a major membrane glycoprotein restricted to leukocytes, was evaluated in paraffin sections of a wide variety of hematopoietic and nonhematopoietic tissues (294 specimens) with monoclonal antibodies (PD7/26 and 2B11). In nonneoplastic tissues, LCA was identified on B and T lymphocytes, with variable immunoreactivities for plasma cells and histiocytes. By light microscopy and ultrastructurally, LCA was localized predominantly to the cell membrane and was also present focally in the cytoplasm. Myeloid cells at all stages of maturation were non-reactive, as were erythroid cells, megakaryocytes, and all non-hematopoietic tissues. Monocytes and mast cells, however, revealed membrane staining for LCA. In nearly all non-Hodgkin's lymphomas of the B- and T-cell types (74 of 80; 93 per cent), the lymphoid infiltrate was immunoreactive for LCA. In specimens from patients with Hodgkin's disease (nodular sclerosis and mixed cellularity type), rare Reed-Sternberg cells stained for LCA. Neoplastic cells were consistently immunoreactive for LCA in specimens from patients with chronic lymphocytic leukemia of the B- or T-cell type, prolymphocyte leukemia, and hairy cell leukemia. However, tissues from only three of eight cases of acute lymphoblastic leukemia were LCA-positive, with most non-reactive specimens exhibiting CALLA (J5) positivity. In cases of multiple myeloma, only minor populations of plasmacytic cells exhibited membrane staining for LCA. Nonhematopoietic neoplasms (102 evaluated), including small cell anaplastic carcinomas, amelanotic melanomas, alveolar rhabdomyosarcomas, Ewing's sarcoma, and germ cell tumors, were uniformly non-reactive. Human LCA represents an excellent cell marker for paraffin sections, to distinguish hematopoietic neoplasms, particularly of the lymphoid type, from poorly differentiated tumors of epithelial, mesenchymal, or neural derivation.

Significance of glycosidase patterns in lymphoid cells

Characteristic patterns of cell bound lysosomal glycosidases were found in different lymphoblastoid cell lines derived from Epstein-Barr virus-transformed lymphocytes. The enzyme pattern resembled that found in normal lymphocytes from healthy individuals except for a marked increase in alpha-L-fucosidase. beta-D-Glucuronidase on the contrary markedly decreased in the lymphoblastoid cells. Burkitt's lymphoma cells on the other hand showed glycosidase patterns that were quite distinct from those in lymphoblastoid cells. Each lymphoma cell line showed a characteristic pattern. This is one indication of a heterogeneous origin of these tumors. Glycosidase patterns may be used to roughly distinguish different lymphoid cell lines.

Flow cytometric analysis of the binding of eleven lectins to human T- and B-cells and to human T- and B-cell lines

The relative surface binding of 11 lectins to human peripheral blood T- and B-lymphocytes, to Molt-4 and JM T-cell lines, and to 6410 and NC37 B-cell lines was determined by flow cytometry. The lectins from Lens culinaris (LCA), Ricinus communis (RCA), Arachis hypogaea (PNA), Abrus precatorius (APA), Ulex europaeus (UEA-F), Sarothamnus scoparius (SAS-F), Helix pomatia (HPA), Phaseolus coccineus (L-PHA), Glycine max (SBA), and Triticum vulgare (WGA) were fluoresceinated and incubated with living, formaldehyde-fixed, or neuraminidase-treated cells. Except LCA, which preferentially bound to the two B-cell lines tested in this study, none of the other lectins exhibited selective binding to the undifferentiated cells of the cell lines. The T-cell lines and, in part, the peripheral blood T-cells bound less WGA, APA, LCA, and L-PHA than the B-cell lines and the peripheral blood B-cells. Binding of PNA was found only after neuraminidase treatment of the cells; the binding of PNA, HPA, and UEA-F after neuraminidase treatment was higher for the T-cells than the B-cells from peripheral blood. No significant differences were detected between both cell types for RCA, ConA, SBA, and SAS-F.

The lectin binding affinity of Reed-Sternberg cells

Reed-Sternberg cells from ten cases of Hodgkin's disease were examined by the direct immunofluorescence technique, for their affinity for nine lectins. The surrounding lymphocytes and monocytes of HD tissue were also assessed for their ability to bind lectins. RS cells showed considerable heterogeneity of reaction. Overall, there was a marked decrease in the binding of most of the lectins studied in HD cases as compared to normal peripheral blood mononuclear cells. This was particularly evident for RCA, PHA and PNA binding. It is suggested that there is a defect in carbohydrate metabolism, with fewer lectin-binding sites on both RS cells and on the mononuclear cell populations in Hodgkin's disease. Further quantitative work is required to verify this.

Surface glycoprotein patterns of B type chronic lymphocytic leukaemia cells correlate with the clinical activity of the disease

The surface glycoprotein patterns of leukaemic B lymphocytes from 20 patients with clinically progressive or non-progressive chronic lymphocytic leukaemia (CLL) were investigated. Cells were labelled by the neuraminidase-galactose oxidase-tritiated sodium borohydride technique and the radioactive proteins were separated by polyacrylamide slab gel electrophoresis and visualized by fluorography. A total of 13 to 16 bands were detected. A common surface glycoprotein pattern for CLL cells was seen in all patients consisting of 7 proteins with the apparent molecular weights of 210, 200, 185, 150, 135, 110 and 90 kilodaltons, respectively. Interesting differences were, however, observed as cells from patients with progressive CLL in general lacked the glycoproteins 120, 72 and 67 K, which were found on cells from inactive CLL. The possible biological and clinical significance of these findings is discussed.

Cell surface glycoprotein patterns of cell lines derived from human small cell carcinoma of the lung

The expression of major cell surface glycoproteins (sgp) of seven established human pulmonary small cell carcinoma (SCC) cell lines and two autologous non-neoplastic lymphoblastoid and fibroblastic cell lines were studied by the galactose oxidase tritiated sodiumborohydride labelling technique. The general sgp pattern of SCC cell lines was different from that of the autologous non-malignant cell lines and the various other normal and malignant hematopoietic cells, gliomas and melanomas previously studied by the same technique, thus confirming that the sgp pattern seems to represent a molecular "fingerprint" of various human cell types. The SCC cell lines could be subdivided into two major subgroups with respect to expression of characteristic sgps. One group of lines was characterized by having prominent sgp 52000 (52 K) Dalton (D), 50 KD, 40 KD, 34 KD and 10 KD. In the other group the major sgps had apparent molecular weights of 110 KD, 75 KD and 10 KD, respectively. In addition to these common basic "group specific" sgps each SCC line expressed individually distinct sgps.

Production and characterization of monoclonal antibodies against the Epstein-Barr virus membrane antigen

Five murine hybridoma lines that produce monoclonal antibodies against Epstein-Barr virus membrane antigen (MA) were established. Immunoprecipitation experiments demonstrated that three of the antibodies precipitated both the 236,000 (236K) MA and the 212K MA. The other two antibodies precipitated the 86K MA. Antibodies against the 236K-212K MA and the 86K MA mediated complement-dependent cytolysis of Epstein-Barr-virus-infected cells. The antibodies against the 86K MA neutralized both the B95-8 and P3HR-1 viruses.

Glycoproteins containing peanut-agglutinin receptors from human-peripheral-blood T-lymphocyte plasma membranes

A glycoprotein fraction possessing peanut agglutinin receptors has been isolated from detergent extracts of neuraminidase-treated human peripheral blood T-lymphocyte plasma membranes with affinity matrices comprising the peanut agglutinin co-valently immobilised on Sepharose 4B. This fraction could be specifically eluted from affinity columns using buffer solutions supplemented with 0.2 M D-galactose and was shown, by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (0.1%), to contain four major glycoprotein components with apparent molecular weights of 200000, 190000, 110000 and 95000. It is suggested, from the observed reactivity of these glycoproteins with various lectins in double-diffusion experiments, that they possess both O-glycosidically and N-glycosidically linked carbohydrates.

Carbohydrate-labelled glycoproteins as markers of human lymphocyte subsets stimulated with mitogen and alloantigen

Human lymphocytes from thymus, spleen, and blood were stimulated by concanavalin A, phytohemagglutinin or pokeweed mitogen to incorporate radioactive thymidine and various carbohydrates. Peripheral-blood lymphocytes were also activated by alloantigen in a mixed lymphocyte reaction. Incorporation of thymidine and carbohydrates was parallel in stimulated cells. Carbohydrate-labelled cells were extracted with Triton X-100 buffer and the extracts subjected to sodium dodecylsulfate/polyacrylamide gel electrophoresis and subsequent autoradiography. From a comparison of the resulting glycoprotein patterns the following conclusions could be drawn. (a) The same population of thymocytes responds to all three mitogens. (b) Pokeweed-mitogen-stimulated blood lymphocytes are similar to this mitogen-responsive thymocyte population. (c) The glycoprotein pattern of pokeweed-mitogen-responsive spleen cells shows two characteristic glycoproteins, GP 50 and GP 78, and resembles that of murine B cells. (d) Whereas concanavalin A and phytohemagglutinin activate identical subpopulations of T cells in the spleen, this is not the case in the blood. (e) Concanavalin-A-activated and alloantigen-activated blood lymphocytes express a glycoprotein GP 185 which is not found on phytohemagglutinin-responsive cells. (f) The kinetic relationship during alloantigen stimulation in a mixed lymphocyte reaction between the appearance of glycoprotein GP 185 and subsequent maximal killing activity in an assay using release of 51Cr makes it likely that glycoprotein GP 185 is a marker for cytotoxic T lymphocytes.

Human T cell proteins recognized by rabbit heteroantisera and monoclonal antibodies

Many structural and functional features of the cell surface antigens of human T cells remain to be characterized. In these investigations, heteroantisera have been used to identify potentially interesting antigens not yet recognized by individual monoclonal antibody preparations. These antigens include patterns of bands (Mr 140-240K) on various T cells and T cell lines, at least six other bands on T cell lines and novel antigens on CTL lines. The majority of these antigens are different from the compiled list of antigens recognized by monoclonal antibodies against T cell proteins. The monoclonal OKT9 recognizes an antigen most prevalent on dividing cells, and this antigen is the same as that recognized by another monoclonal antibody, 5E9, and by previously described heteroantisera. The monoclonal antibody 4F2 has a distribution similar to OKT9, but it is structurally distinct, and is also present on monocytes. Three T cell surface proteins, two defined by the monoclonal antibodies OKT6 and OKT10, recognize proteins which resemble HLA antigens physiochemically. OKT6 and NAI/34 both recognize a 49,000 glycoprotein which is associated with a 12,000 subunit which reacts with anti-beta 2-microglobulin antibodies. OKT10 recognizes a 46,000 protein, also found with a 12,000 peptide, while the third protein, a beta 2-microglobulin-associated glycoprotein of 43,000 is not yet defined by a monoclonal Ab. Other monoclonals described here include 3A1 and PVR-11, which are on subsets of peripheral T cell, and B1-192 and B1-499 which are on some activated T cells.

Membrane asymmetry. A survey and critical appraisal of the methodology. I. Methods for assessing the asymmetric orientation and distribution of proteins

This and the companion article are aimed at surveying the methods used for the study of membrane asymmetry. The techniques employed for the assessment of the asymmetric distribution and orientation of membrane proteins are reviewed in this article, whereas those pertaining to the unequal distribution of lipids are detailed in the companion paper. The use of immunological techniques and lectins, functions of proteins and their perturbations, chemical reagents, enzymatic isotopic labeling and enzymatic cleavage of membrane proteins and physical techniques are discussed and illustrated using recent examples of their application. Whenever appropriate, problems involving crypticity and non-availability or non-reactivity of functional sites, relevant chemical functions or protein fragments to appropriate ligands, reagents or modifying enzymes are envisaged and possible modification of the exposure of proteins during preparation of ghosts and other drawbacks are discussed, the use of different techniques and control experiments in conjunction is recommended for a more realistic assessment of the distribution and orientation of proteins.

Comparison of isolated peanut agglutinin receptor glycoproteins from human, bovine and porcine erythrocyte membranes

Affinity chromtography has been used to isolate and compare the peanut agglutinin receptors from neuraminidase-treated human, bovine and porcine erythrocyte membranes. Passage of Triton X-100-solubilised membrane material through either Sepharose- or acrylamide-based affinity columns resulted in the reversible binding of receptor molecules to the immobilised lectin. Elution with 0.2 M galactose released specifically bound glycoprotein fractions, the composition and molecular weights of which were determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Carbohydrate analysis by gas chromatography identified these bound glycoprotein fractions as the major sources of the O-glycosidic-linked disaccharide galactosyl-beta-(1 leads to 3)-N-acetylgalactosamine in these membranes. It is suggested that these isolated fractions represent a discrete population of glycoproteins within the membranes studied, which possess both O-glycosidic- and N-glycosidic-linked carbohydrates.

Lectin staining of carbohydrates of haemic cells. II. The cells of normal lymphoid origin, of lymphatic leukaemias and related diseases

Normal and leukaemic lymphoid cells, both human and murine, were stained for specific carbohydrates with three fluorescein-labelled lectins: Aprotinin for sialyl (or uronyl) groups: Ricinus agglutinin for galactosyl groups; and Concanavalin A for mannosyl (or glucosyl) groups. The method gives permanent preparations of sections from methanol fixed, paraffin embedded tissues, from blood and bone marrow films or touch preparations of lymph nodes that were methanol fixed. Whereas normal lymphocytes and lymphoblasts reacted strongly for sialyl groups, lymphoblasts of acute lymphoblastic leukaemia and lymphocytes of chronic lymphocytic leukaemia gave a much weaker reaction. The same was the case of the lymphocytes of the Sézary variant and the lymphocytes of macroglobulinaemia. The fine processes of the cells of hairy cell leukaemia stained well for sialyl groups. No obvious differences were detected between normal monocytes and the cells of monocytic leukaemia, nor between normal plasma cells and those of myeloma.

Characterization of the monoclonal blood and bone marrow B lymphocytes in Waldenström's macroglobulinaemia

Blood lymphocytes were studied in sixteen patients with Waldenström's macroglobulinaemia. In four of them bone marrow lymphocytes were studied simultaneously. In all four a monoclonal lymphocyte plasma cell fraction carrying the light chain isotype of the serum M-component was identified by direct immunofluorescence. The cell-bound immunoglobulins had idiotypic structures in common with the serum M-component. The monoclonal cell component was pleomorphic, varying from small lymphocytes carrying surface IgM/IgD or IgM only to plasmacytoid cells with both surface and cytoplasmic IgM to mature plasma cells with only cytoplasmic IgM. A differentiating B-cell clone was further suggested by the sequential loss of complement and Fc receptors during maturation to plasma cells. In nine patients monoclonal lymphocytes were increased also in blood. However, the monoclonal fraction was small in all except two patients with advanced disease. The results support the assumption that a clone of B lymphocytes differentiates into immunoglobulin-secreting cells in Waldenström's macroglobulinaemia. The pattern of cell differentiation in bone marrow was the same in patients with and without a monoclonal blood cell fraction. Progression of the disease is probably the main factor determining the appearance of large numbers of tumour cells in blood.

The major sialoglycoprotein of human T-lymphocytes

Human, peripheral-blood T-lymphocytes and human, T-lymphoblastoid cells of a MOLT 4B cell-line were surface-labeled by lactoperoxidase-catalyzed iodination, periodate and sodium borotritide, and galactose oxidase and sodium borotritide, and analyzed by dodecyl sodium sulfate-polyacrylamide gel-electrophoresis. Both types of cells were found to show a major, cell-surface sialoglycoprotein with an apparent mol. wt. of 95,000. After neuraminidase treatment, this glycoprotein showed a higher mol. wt. of 120,000. The major sialoglycoprotein of both types of cells bound to wheat-germ agglutinin and concanavalin A and, after neuraminidase treatment, to Arachis hypogaea agglutinin. The glycopeptides obtained from these glycoproteins by Pronase digestion gave similar elution-profiles on Sephadex G-50 gel filtration. These results suggest that the major sialoglycoprotein of normal T cells and that of MOLT 4B cells are very similar, if not identical.

Metabolic carbohydrate-labelling of glycolipids from mouse splenocytes. Mitogen-stimulated B and T cells show different labelling patterns

Splenic lymphocytes from CBA/J, AKR/A/J, BALB/c/A, C57/BL/6J, C3H/HeJ and C3H/Tif nu/nu mice and B lymphocyte or T lymphocyte preparations derived from CBA/J mouse spleen were cultivated in the presence of either concanavalin A, phytohemagglutinin, Salmonella minnesota R595 lipopolysaccharide or Proteus mirabilis soluble lipoprotein. The mitogens stimulated the incorporation of [14C]galactose into acid-insoluble cell material with the same specificity for B or T cells as that known for thymidine incorporation. The glycolipids extracted from mitogen-activated, carbohydrate-labelled B or T cells were compared by thin-layer chromatography and characteristic differences between B and T cells were noted in the ganglioside as well as in the neutral glycolipid fractions. In addition, subsets of B or T cells, namely lipopolysaccharide-responsive or lipoprotein-responsive B-cell populations or nylon-purified T cells may be recognized by characteristic neutral glycolipid bands.

Biochemical identification of primate lymphoid cell-surface glycoproteins

We have employed the galactose oxidase-tritiated sodium borohydride labelling method to examine the surface glycoproteins of cotton-topped marmoset and other primate cell lines either established from tumors or transformed in vitro by different lymphotropic herpesviruses. The labelled surface glycoproteins were separated on acrylamide gels in the presence of sodium dodecyl sulfate (SDS) and analyzed by fluorography. Our results indicate that (1) lymphocytes of the same class from different primate species are similar but can be distinguished; (2) T and B lymphocytes of the same species can be differentiated; (3) cotton-topped marmoset lymphocytes of the same class show marked similarities regardless of tumor or in vitro origin or virus used for transformation; (4) three cell lines established from different EBV-induced tumors of the same marmoset show essentially the same labelling pattern, supporting the hypothesis that they originated from a single clone.

Comparison of polypeptides from cultured human fibroblasts and sarcoma cells

The proteins in cell layers of cultured normal diploid human skin (ES, ER) and lung (WI-38) fibroblasts were compared to those of SV40-transformed human fibroblasts (WI-38/VA-13), human rhabdomyosarcoma (RD) and fibrosarcoma (HT-1080) cells using metabolic amino acid and sugar labeling and surface labeling with tritiated sodium borohydride after oxidation with galactose oxidase. The labeled proteins were analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography (fluorography). A transformation-associated decrease in the pericellular glycoprotein fibronectin (subunit molecular weight, 220 000) and in the synthesis of a set of polypeptides in the 130 000--180 000 dalton region was seen. Synthesis of a glycosylated 160 000 dalton polypeptide was markedly reduced. In transformed cells distinct increases of several specific polypeptides was detected in both [35S]methionine and [3H] mannose incorporation experiments but not using the surface labeling method.

Identification and characterization of normal and malignant human blood leukocytes by surface glycoprotein patterns

We have labeled surface glycoproteins of normal and malignant human blood leukocytes by the galactose oxidase-NaB3H4 and periodate-NaB3H4 labeling techniques. The labeled glycoproteins were separated by slab gel electrophoresis in the presence of sodium dodecyl sulfate and visualized by fluorography. The different types of normal blood cells could be distinguished by their surface glycoprotein patterns. The surface glycoproteins of cells from patients with acute lymphoblastic, myeloid, or monoblastic leukemia were different from those of normal cells. The leukemic cells could be classified by their surface glycoprotein patterns with respect to their relationships to normal blood cells, and an estimation of their degree of differentiation was obtained.

Lymphocyte plasma membranes. VI. Plasma membrane glycoproteins of thymic and splenic lymphocytes from inbred rats

Plasma membranes of splenic and thymic lymphocytes from ACI rats were analyzed for their protein and glycoprotein components by surface radioiodination with 125I and SDS-polyacrylamide gel electrophoresis. The glycoproteins were extracted with lithium diiodosalicylate, characterized and assayed with antisera to thymic antigen. Plasma membranes of both cell types showed more than 25 proteins of which 10--15 were glycoproteins. Both cells showed five major glycoproteins but their apparent molecular weights or intensities differed. Surface radioiodination showed a 120 000 daltons component, common to both cell types, and a 27 000 daltons thymus-specific component as the most exposed surface glycoproteins. Lithium diiodosalicylate extracts of the plasma membranes contained almost all of the glycoprotein components and comprised 5-6 percent of the total membrane protein and 40-50 percent of the total membrane carbohydrate, with sialic acid content in thymus twice that of the spleen cells. About 1 percent of the total plasma membrane protein and 7 percent of the total isolated glycoproteins from thymocytes were reactive with rabbit anti-rat thymocyte antiserum and the immune precipitates showed two components with apparent molecular weights of 72 000 and 27 000.

Surface glycoprotein patterns of normal and malignant human lymphoid cells. I. T cells T blasts and leukemic T cell lines

Exposed surface glycoproteins of resting and in vitro activated human T lymphocytes and leukemic T-cell lines were labelled by the galactose oxidase-tritiated sodium borohydride method. The labelled glycoproteins were separated by polyacrylamide slab gel electrophoresis and visualized by autoradiography. The basic glycoprotein patterns of the T lymphocytes and T blasts were found also in the leukemic T cells. The glycoprotein pattern of the T-cell lines was easily distinguishable from that of other hematopoietic cell lines. The findings suggest that: (1) surface glycoprotein analysis might be useful for the identification of cell lines and for the differential diagnosis of hematopoietic malignancies; and (2) cells of cultured T lines may be used for the identification and preparation of T lymphoid differentiation antigens and perhaps also tumor-associated surface molecules.