Mobility of Concanavalin A receptors on the surface membrane of lymphocytes from normal persons and patients with chronic lymphocytic leukemia

Energy transfer efficiency on lymphocytes of leukemia patients measured by fluorescence polarization

Measurements of fluorescence resonance energy transfer efficiency (E), via fluorescence polarization, have been applied to distinguish between chronic lymphocytic leukemia (CLL) patients and healthy persons. Capping of Concanavalin-A receptors is more pronounced in normal lymphocytes than in those of CLL patients. Membrane capping decreases the distance between donor and acceptor molecules embedded in the membrane (r), and thus increases the monitored energy transfer efficiency (E approximately 1/r6). Blood samples of 10 healthy subjects and 16 CLL patients were examined. In the healthy subjects, the mean E value for capped lymphocytes was 19 +/- 3, whereas in the CLL patients it was significantly lower (8 +/- 5) (P < 0.01).

A rapid method for quantitating lymphocyte receptor capping: capping defect in AIDS patients

Capping of concanavalin A (Con A) and anti-Leu-8 (L8) receptors on human peripheral blood mononuclear (PBM) membranes was studied utilizing fluorochrome-conjugated ligands and flow cytometric analysis. Histogram profiles of fluorescent intensities consistently revealed a time-dependent decrease in numbers of brightly fluorescing events concurrent with an increase in numbers of dimly fluorescing events when capping occurs. Differences in fluorescence profiles were detectable by flow cytometric analysis as early as 5 min after capping conditions were initiated. A pronounced defect in receptor capping of PBM cells from AIDS patients was observed. This technique represents a rapid and reproducible means for detecting early changes in cell membrane receptor mobility.

Sublines of the Burkitt line Daudi, selected on the basis of reactivity with soybean agglutinin, differ in tumorigenicity in athymic mice

Two subpopulations were isolated on the basis of soybean agglutinin (SBA) binding, from the human Burkitt lymphoma line Daudi. The low- and high-binder sublines maintained this characteristic in continuous passages. Their surface marker profiles, antibodies, scanning electron microscope (SEM), cytochemical reactions and binding of other lectins (concanavalin A and wheatgerm agglutinin) were not different. They differed, however, in growth potential in athymic mice. The low-binder subline had lower frequency of takes, tumor weight and volume, and did not metastasize as compared to the high-binder subline. However, the reaction with F-SBA of all the tumor cells examined was strong (greater than 70%), indicating in vivo selection and tumor development of high binder cells.

Malignant transformation in inverted papilloma

The detection of markers associated with malignancy will help in the early identification of tumors and assessment of the success of treatment in patients suffering from carcinoma. Three characteristics investigated in this study were found to differentiate a premalignant inverted papilloma from a benign simple nasal polyp.

Concanavalin A receptors on the surface membrane of lymphocytes from patients with acute leukemia

Peripheral blood mononuclear cells (PBM) isolated from 23 patients with acute lymphoblastic leukemia (ALL) and 24 with acute non-lymphoblastic leukemia (ANLL) were studied for binding and mobility of Concanavalin A (Con A) receptors, using fluorescent Con A (F-Con-A). The cap forming ability of PBM from all patients was 18.7 (+/- 9.3%) and 18.9 (+/- 9.9%) for ANLL patients at the time of diagnosis or during relapse. During clinical complete remission the cap forming ability of the PBM did not change significantly. No correlation was observed between the percentage of blasts present in the peripheral blood at the time of examination and the extent of cap formation, for both types of leukemia. The pattern of F-Con-A binding to PBM in ANLL patients was different compared to that seen in ALL. In ANLL, the fluorescent stain was concentrated in a round body on the cell ("button form") after binding to the membrane, while the rest of the cell showed almost no fluorescence. The present results indicate that PBM cells from patients with acute leukemia are characterized by a high degree of Con-A receptor mobility.

Membrane modification differentially affects the binding of the lactogenic hormones human growth hormone and ovine prolactin

Human growth hormone (hGH) and ovine prolactin (oPRL) are both lactogenic as defined by their ability to induce milk-protein synthesis in vitro in the presence of insulin and hydrocortisone. At physiological concentrations, both hGH and oPRL have similar dose-response curves in a mouse mammary gland organ culture system. Binding of 125I-labeled hGH (125I-hGH) to lactogenic receptors is competed by both hGH and oPRL, and the competition curves are nearly superimposable. Moreover, solubilized membrane proteins bound with either 125I-hGH or 125I-labeled oPRL (125I-oPRL) show the same sedimentation pattern on sucrose gradients. However, methylation of membrane phospholipids in the presence of the methyl donor S-adenosyl-L-methionine only increases the binding of 125I-hGH. Binding of either 125I-oPRL or 125I-labeled bovine growth hormone (125I-bGH) was unaffected. Addition of concanavalin A (Con A) to the membranes decreased binding of 125I-oPRL to the lactogenic site by 80%, whereas 125I-hGH binding was decreased by only 40%, with the binding of 125I-bGH unaffected. However, both hGH-and oPRL-bound proteins bind to Con A-Sepharose columns to the same extent. These results suggest that although hGH and oPRL bind to the same lactogenic site with similar affinities and elicit similar biological responses, modification of membranes either by phospholipid methylation or by Con A differentially affects the binding of these two hormones.

Cellular and molecular aspects of immune system aging

We begin with a brief discussion of the importance and advantages of immune studies to the problem of aging. This is followed by a short over-view of immune system aging at the systemic level. The major portion of the article is a review of observation, both at the cellular and molecular level, of changes in aging immune cells, with sections on intercellular communication, membrane phenomena, cyclic nucleotides, and molecular genetic changes.

Effects of linoleic acid on capping, lectin mediated mitogenesis, surface antigen expression, and fluorescent polarization in lymphocytes and BHK cells

The incubation of linoleic acid with cells causes profound effects on membrane asociated phenomenon. Using the fluorescent probe diphenyl hexatriene (DPH) to monitor lipid changes in the microenvironment of the cell surface, we find that linoleic acid reduces the polarization values (P) in mouse lymphocytes and BHK cells. Measurements on lipids extracted from the cells grown in linoleic acid produce similar results. We also find in the mouse lymphocyte that capping of Ig is inhibited and con A stimulated mitogenesis is unaffected. In contrast to the latter effect, LPS and PHA stimulated mitogenesis is inhibited and in the rat lymph node, con A stimulated mitogenesis, greatly enhanced. We also show that linoleic acid alters the binding of antibodies to the cell surface of EL-4 lymphoma cells. These observations suggest that linoleic acid alters cellular function by interfering with protein/lipid interactions within the surface membrane.

Huntington's disease: abnormality of lymphocyte capping

Concanavalin A-induced lymphocyte capping was studied in 30 patients with Huntington's disease (HD) and 39 controls. A significant decrease in lymphocyte capping was seen in the 24 patients with HD less than 60 years of age compared to 25 age-matched controls (p less than 0.01); above age 60, differences between patients with HD and controls were not significant. These findings lend support to previous observations that generalized membrane abnormalities are present in patients with HD. Studies of HD lymphocyte capping may permit a detailed analysis of membrane function in cells that are readily obtained from living patients.

Binding of fluoresceinated lectins to normal and dinitrofluorobenzene treated human leucocytes

Using fluoresceinated lectins we have shown the receptor distribution on normal human granulocytes and lymphocytes following tagging with 1-fluoro- 2, 4-dinitrobenzene (DNFB). DNP-tagged cells exhibited strong, smooth membrane staining and produced smaller patches dispersed uniformly over the entire cell surface.

Merocyanine 540 as a fluorescent probe of membranes: selective staining of leukemic and immature hemopoietic cells

We have reported (Easton, Valinsky and Reich, 1978) that merocyanine 540 (MC 540) specifically stains a variety of living excitable cells, but not nonexcitable cells. This paper describes the exceptional permeability to MC 540 of leukemic leukocytes and immature hemopoietic precursor cells. We have used fluorescence microscopy and uptake of radioactive dye to study MC 540 staining of peripheral blood leukocytes from 80 leukemic and 34 normal individuals; leukemic leukocytes stain, whereas normal leukcytes do not. The leukocyte staining reaction differs from that previously described for excitable cells since it is independent of the ionic composition of the staining medium, kinetically complex, enhanced by light, enhanced by oxygen and essentially irreversible. Virtually all circulating nucleated cells from leukemic individuals are stained to approximately the same extent, and there is no qualitative or quantitative distinction between the various forms of leukemia. We have also found that MC 540 interacts with granulopoietic colony-forming cells (CFU-C) and with spleen colony-forming cells derived from mouse bone marrow (CFU-S). We cannot as yet identify a specific property of leukocyte plasma membranes that determines MC 540 permeability; since changes in MC 540 uptake appear to be correlated with cellular maturation during normal hemopoiesis, the retention of staining by leukemic cells, some of which appear morphologically normal, may indicate of failure in membrane maturation during leukemic blood cell development.

Scanning electron microscopic investigations of acute leukemia

Twenty cases of acute lymphoblastic leukemia (ALL) in children and adults were investigated at different tissue localizations by scanning electron microscopy. ALL was divided into cases with or without strong paranuclear acid phosphatase activity. ALL showed very similar surface morphology irrespective of the type of ALL or the tissue localization. ALL is, however, strikingly different in some from other childhood leukemias and lymphomas, as well as from activated T-lymphocytes in infectious mononucleosis. The results indicate that the surface morphology of leukemic cells is a stable cytologic parameter, if certain technical prerequisits are fulfilled. Further criteria may thus be added to the panel of known cytologic, cytochemical and functional parameters.

Surface membrane changes in lymphocytes from patients with infectious mononucleosis

Peripheral blood lymphocytes from 20 patients with acute infectious mononucleeosis (IM) were studied for cell aggregation and for cap formation by concanavalin A (Con A). The lymphocytes from these patients showed 5.2+/-1.5% cells with a Con-A-induced cap and a high degree of cell aggregation without Con A, compared to 27.7+/-3.2% caps and a low degree of cell aggregation with normal lymphocytes. The lymphocytes from IM patients were fractionated to enrich for T and B cells. There was a low frequency of cap formation in both T and B cells, but the high degree of celll aggregation without Con A only occurred with B cells. Studies with four patients in clinical remission from acute IM have shown that the frequency of Con-A-induced cap formation only returned to normal more than 3 months after the beginning of clinical remission and that even at 6 months the cells still showed a high degree of cell aggregation. The results indicate that a high degree of B-cell aggregation and a low percentage of B and T cells with a Con-A-induced cap were associated with acute IM and that the changes associated with a high degree of B-cell aggregation were by themselves not sufficient to cause the disease.

Establishment in continuous culture of a new type of lymphocyte from a "Burkitt like" malignant lymphoma (line D.G.-75)

The isolation and establishment in vitro of a hitherto undescribed type of lymphocyte designated D.G.-75 is reported. The original inoculum was derived from the pleural effusion of a child with a primary abdominal lymphoma, which clinically and histologically resembled Burkitt's lymphoma. In addition to the absence of the EBV genome and EBV receptors, this line possesses a number of other properties which distinguish it from previously described lymphoblastoid cell lines. It has different growth characteristics and morphology; does not form EAC or E rosettes (representative of B and T) cell surface markers, respectively); possesses IgM-kappa immunoglobulins on the cell surface (B lymphocyte), has an unusually high cap-forming ability and low agglutinability with fluorescent concanavalin A. One homologue of the No.14 chromosome pair possesses extra chromatin material as revealed on chromosome banding. This abnormal chromosome marker is similar to that described in biopsies and cultured tumor cells from patients with African Burkitt's lymphoma.

Concanavalin A receptors on the surface membrane of lymphocytes from patients with African Burkitt's lymphoma and lymphoma cell lines

Lymphocytes isolated from the peripheral blood and from tumor tissues of patients with African Burkitt's lymphoma have been studied for cap formation and agglutinability by Concanavalin A (Con A). Peripheral blood from healthy adult persons served as a normal control and blood from patients with carcinoma served as a non-lymphoma control. These studies included 29 patients with Burkitt's lymphoma, 93 with carcinoma, and 105 healthy adult persons, as well as tumor tissues from 13 patients with Burkitt's lymphoma. The great majority of the carcinomas were from the face and neck regions. Lymphocytes from the blood of the majority of patients with Burkitt's lymphoma, as well as those from tumor tissues, exhibited a reduced cap-forming ability (2-6%) and increased Con-A-induced agglutinability compared to lymphocytes from healthy normal donors and from patients with carcinoma, although some of the lymphocytes from patients with carcinoma had a somewhat lower range of cap formation than the lymphocytes from healthy donors. No difference was observed in the interaction with Con A of lymphocytes from the different types of carcinoma studied. Eight lymphoid cell lines were established in our laboratory from the tumor tissues of patients with Burkitt's lymphoma. The cap-forming ability and agglutinability by Con A of these lines was examined and compared to those of the "classical" lymphoma lines: Raji, Daudi and P3HR1. All cell lines exhibited an increased Con-A-induced agglutinability and a reduced cap-forming ability compared to normal lymphocytes, except for P3HR1 cells which exhibited a cap-forming ability of 15-20%. These findings are discussed in relation to the association of the lymphocytes with malignancy and as a possible aid in the differential diagnosis between malignant lymphomas and other diseases.

Lectin agglutinability of non-neoplastic and neoplastic human lymphoid cells in vitro

Agglutination by two lectins, Concanavalin A (Con A) and Ricinus communis agglutinin (RCA), has been investigated in a human lymphoid cell system. The main conclusions of this study are: (1) no systematic correlation exists between the neoplastic state and sensitivity to Con A or RCA; (2) cells of neoplastic lines vary unsystematically in their surface properties as evaluated by Con A agglutination, with the possible exception that presence of Epstein-Barr virus (EBV) is associated with a high degree of agglutination and (3) cells of diploid lymphoblastoid lines and phytohemagglutinin (PHA)-stimulated lymphoctes agglutinate similarly and significantly better than unstimulated T- or B-lymphocytes. The relatively simple Con A agglutination assay can be used as an adjunct in classification of human lymphoid cell lines.

Membrane difference in peripheral blood lymphocytes from patients with chronic lymphocytic leukemia and Hodgkin's disease

Lymphocytes were isolated from the peripheral blood of 21 normal persons and 66 patients with chronic lymphocytic leukemia (CLL), CLL in remission, Hodgkin's disease, Hodgkin's disease in remission, various other tumors, or cardiovascular diseases; The lymphocytes were studied for cap formation and agglutinability by concanavalin A, and for cell attachment to the surface of a petri dish. The frequency of cap formation was lowest in lymphocytes from patients with untreated Hodgkin's disease (2.1 plus or minus 0.8%), next lowest in lymphocytes from patients with CLL who were or were not under treatment (7,0 plus or minus 1;3%), and also low in Hodgkin's disease in remission (10.6 plus or minus 1.2%). The frequencies of cap formation by lymphocytes from patients with various other tumors (19.1 plus or minus 2.5%), with CLL in remission (24.0 plus or minus 0.9%), and with nonmalignant diseases (26.0 plus or minus 2.2%) were more similar to the frequency found in lymphocytes from normal persons (29.4 plus or minus 2.8%). Lymphocytes from all the patients, including those in remission, showed a higher degree of agglutinability by concanavalin A than lymphocytes from normal persons. Cell attachment to a petri dish was highest with CLL, next highest with CLL in remission, and low for normal persons and all the other patients. Lymphocytes from normal persons that consisted predominantly of thymus-derived cells gave similar results to isolated normal bone marrow-derived cells. The results indicate that there were different changes in the surface membrane of lymphocytes from patients with CLL, CLL in remission, Hodgkin's disease, and Hodgkin's disease in remission, and that the patients in clinical remission still showed abnormalities in their lymphocytes.

Concanavalin A receptors on the surface membrane of lymphocytes from patient's with Hodgkin's disease and other malignant lymphomas

Concanavalin A (Con A) induces movement of its receptors on the cell surface membrane. This induction results in a concentration of Con A site complexes on one pole of the cell to form a cap. A marked difference was found in the mobility of Con A receptor between lymphocytes from normal persons and lymphocytes from patients with Hodgkin's disease and other malignant lymphomas. Lymphocytes isolated from tonsils of patients undergoing tonsillectomy and from axillary lymph nodes of breast cancer patients exhibited approximately 30% of cells with caps, which is identical with the cap formation ability of normal lymphocytes. In biopsy material from patients with Hodgkin's disease and other malignant lymphomas, a significant decrease in the ability of the lymphocytes to form caps was observed. This difference in the mobility of Con A sites was even more pronounced in lymphocytes isolated from the peripheral blood. In 123 patients with Hodgkin's disease and other malignant lymphomas, cap formation ranged between 3 and 12%. The ability of cells, from a normal donor or a lymphoma patient, to form caps was independent of the source from which the lymphocytes were isolated, e.g., lymph node, spleen, or blood. Lymphocytes from patients with lymphoma were also agglutinated by Con A to a higher degree than normal lymphocytes. These findings are discussed in relation to the association of the lymphocytes with these malignancies and as a possible aid in their differential diagnosis.