Hybridization of a myeloid leukemia-derived human cell line (K562) with a human Burkitt's lymphoma line (P3HR-1)

The myeloid leukemia-derived Epstein-Barr virus (EBV)-negative human lymphoid cell line K562 was successfully hybridized with the EBV-carrying Burkitt's lymphoma line P3HR-1. Authenticity of the hybrid PUTKO-1 was established by chromosome and isoenzyme studies. A virtually complete hybrid PUTKO-1 carried the EBV genome derived from the lymphoma parent. It averaged 26 EBV DNA copies per cell and was 100% positive for Epstein-Barr virus-associated nuclear antigen (EBNA). In most respects, the hybrid resembled the K562 parent: It had a high Fc receptor concentration, high sensitivity to natural killer cells, absence of EBV C3 receptors, and deficiency of membrane-associated beta 2-microglobulin (beta 2M) and HLA, in parallel with intracellular synthesis and secretion of beta 2M to the medium. Unlike the P3HR-1 parent, the hybrid was completely nonpermissive for antigens of the EBV cycle, early antigen, and viral capsid antigen. None of the 3 inducing agents, 5-lodo-2'-deoxyuridine, 12-O-tetradecanoyl-phorbol 13-acetate, or sodium butyrate, caused any viral antigen synthesis in PUTKO-1 in contrast to the good inducibility of the parental P3HR-1 subline. Thus the myeloid parent restricted expression of EBV antigens except EBNA. This exception further supports the concept that EBNA is an autonomous function of the viral genome, independent of host cell control that regulates expression of antigens related to the viral cycle. On the contrary, extinction of viral antigens in this hybrid between 2 cell lineages supports our previous concept that the ability to produce viral antigens is similar to a differentiated B-cell property.

Characterization of a human ovarian teratocarcinoma-derived cell line

A cell line (PA I), derived from human ovarian teratocarcinoma cells, was obtained by culturing ascitic fluid cells from a patient with recurrence of malignant ovarian teratoma. During early passages the cultured cells showed a variable morphology, a long doubling time, and a low plating efficiency (2%). After about 50 passages in vitro, a cell population which was more homogeneous and resembled embryonal carcinoma cells were obtained. These cells had a shorter doubling time (26 h), and increased plating efficiency (77%). The early-passage cells were aneuploid (P 24) whereas the late-passage cells had a normal diploid karyotype with one balanced translocation between chromosomes No. 15 and No. 20 (P 224). Details of the karyotype suggest that the cells are heterozygous, i.e. derived from a stage before the first meiotic division. One of the two X chromosomes were inactive, and the cells expressed HLA antigens (A28 and B12), and beta 2-microglobulin. Expression of F9 antigen, characteristic of two-cell and later preimplantation embryos, was absent, while expression of PCC4 antigen, expressed also by blastocysts, was present. This finding suggests that the line might express some embryonic characteristics. The PA I cell line maintained in monolayer cultures showed several characteristics of malignant cells. The proportion of malignant cells increased with successive passages in vitro. The late-passage cells represented a fairly homogenous population of malignant cells similar to embryonal carcinoma cells. Late-passage PA I cells, when seeded under conditions that prevented attachment of cells to the substratum, formed embryoid bodies consisting of an inner core of cells similar to embryonal carcinoma cells, surrounded by a rind of endoderm-like cells. These two cell layers were separated by a basement membrane-like structure containing fibronectin. The core embryonal carcinoma cells expressed high alkaline phosphatase activity whereas the endoderm-like cells had low alkaline phosphatase activity. Embryoid bodies seeded on an adhesive substratum formed polycystic structures divided by layers of epithelial-like cells and containing extracellular fibrils similar to collagen type I or III. In these cultures, further limited differentiation into endoderm-like, epithelial-like cells and pigmented cells was observed. Morphological differenciation of undifferentiated PA I cells into endoderm-like cells in monolayer cultures could be obtained by treatment with BrdUrd or by plating in low serum concentration and at low density. Cells with characteristic fibrillar distribution of fibronectin and actin microfilament bundles were then observed, indicating formation of cells lacking properties of malignant cells. As indicated by these results, the PA I cell line, in spite of a limited capacity to differentiate in vitro, shares some of the properties of mouse teratocarcinoma cell lines and might therefore serve as a useful model for studies on some developmental mechanisms in human cells.

Detection of virus and cellular-determined antigens in situ using [125I]protein A and autoradiography

The present paper describes the use of [125I]Protein A, isolated from Staphylococcus aureus, in detecting antigen-antibody complexes by autoradiography on single cells. the method is relatively quick, reproducible, potentially more sensitive than immunofluorescence, and should be useful in combination with conventional radioimmuno-assays. We have used it to detect the cellular expression of IgM, kappa, lambda, and beta 2-microglobulin, as well as the expression of Epstein-Barr Virus (EBV)-associated antigens expressed in human lymphoblastoid cell lines.

Absorption of boron after mouthwash treatment with Bocosept

Healthy volunteers and patients with gingivitis were treated locally with the boron-containing bacteriostatic agent, Bocosept. Blood levels and urinary excretion of boron were examined by a spectrophotometric method. Blood concentrations after a single mouthwash with Bocosept slightly exceeded those after intake of 200 g raisins or a bottle of red wine. The blood levels during a one-week course of treatment showed a low rate of boron accumulation. The highest concentration was about 0.3 microgram B/ml, a level which does not seem to involve any risk of boron poisoning. The small amount taken up after mouthwash treatment with Bocosept does not appear to represent absorption by the oral mucosa. It seems more likely that the uptake of boron takes place in the intestine after ingestion of residual amounts from the mouth.

Agarose isoelectric focusing of native human immunoglobulin M and alpha 2-macroglobulin

The resolution of native 19S IgM and alpha 2-macroglobulin by agarose isoelectric focusing is described. The agarose used was practically charge free, thus avoiding disadvantages of electroendoosmosis, and gives a very large network gel, with minimal molecular sieving effects. The resolving power is comparable to that obtained in thin-layer isoelectric focusing in polyacrylamide gel. Clones of human IgM showed a microclonal heterogeneity, similar to IgG antibody heterogeneity, alpha 2-macroglobulin gave a pattern of seven bands in the pI range of 4.1 to 4.9. The flexibility of the agarose isoelectric focusing (IEF) system with regard to immunodetection techniques is illustrated by the use of immunofixation and two-dimensional crossed immunoelectrofocusing. The agarose IEF method has several advantages, viz., non-toxicity, simple handling, uniform and rapid gel formation, and considerably shortened fixing and staining times. The value of the new method is discussed, in particular its usefulness in detecting and isolating IgM antibodies of known specificity produced by cells in culture.

Target-effector interaction in the natural killer cell system: isolation of target structures

A sensitive target binding assay has recently been shown to detect natural killer (NK) cells in the mouse. Preincubation of NK cells with detergent-solubilized cell-surface proteins of YAC lymphoma cells prevented subsequent binding to intact YAC targets. The NK target structures (NK-TS) consisted of three molecular species tentatively assigned molecular weights of 130,000, 160,000, and 240,000 based on electrophoretic mobility in sodium dodecyl sulfate/polyacrylamide gels. Moloney cell surface antigen (MCSA), gp71, p30, H-2, and NK-TS were localized in distinct fractions of gels. The NK-TS bound to concanavalin A-Sepharose columns and could be eluted with the specific sugar, suggesting that the target structures may be glycosylated. NK-TS molecules could not be detected in gels of NK-insensitive target cells such as P815, A9HT, YWA, or EL-4. The quantity obtained from the gels varied directly with the NK sensitivity of YAC which is more sensitive when grown in vitro than when grown in vivo. The NK-TS molecules specifically inhibited the binding of NK cells but not alloimmune T cells to their appropriate targets. Additional NK-sensitive tumor cells also expressed some or all of the target molecules exhibited by YAC. Some of these structures shared specificities in the case of MPC-11 or were unique in the case of Molt-4 and K562, as shown by cross-inhibition studies. These results suggest that NK-sensitive cell lines express distinct target structures with possible relevance to natural tumor resistance.

Double immunoglobulin production in cloned somatic cell hybrids between two human lymphoid cell lines

Several clones of independently established somatic cell hybrids between two human lymphoid cell lines, Raji and Namalwa, were examined for surface immunoglobulin expression. Double-antibody radioimmunoassays were established for kappa and lambda light chains. Immunoglobulins were detergent-extrated by Triton X-100 and quantified by radioimmunoassay. The Raji parent expressed small amounts of kappa chains on its surface, and the Namalwa parent a 10 fold greater amount of lambda chains. We show that the majority of the hybrid clones co-express both parental phenotypes.

Somatic cell hybrids between human lymphoma lines. III. Surface markers

Hybrids between two human lymphoma lines, Raji and Daudi (8A) and Raji BJAB (83) were examined for genetically determined and/or differentiation-related surface markers. HL-A B ce-l alloantigens, Fc and complement receptors, EBV receptors and beta2 microglobulin showed an autonomous ("co-dominant") expression in the hybrid. This is in contrast to most previous studies on other differentiation markers, involving as a rule crosses between cells of different lineages, where the differentiated pattern usually became "eclipsed" in the hybrid. Staining of activated complement and complement consumption tests showed intermediate or partially suppressed expression in the hybrids. This may be viewed in relation to the fact that these reactions do not merely depend on complement binding to the receptor, but also on subsequent activation and binding of the activated complement. A more complex interaction is also suggested for immunoglobulin production. Surface immunoglobulin showed a suppressive or intermediate pattern in both hybrids, whereas intracellular kappa chain production showed an amplification in the 83 hybrid. The beta2 microglobulin deficiency of the Daudi parent was corrected in the Raji/Daudi hybrid. Two new HL-A specificities,A10 and BW17, appeared on this hybrid which were not present on the parental lines. This suggests that the HL-A deficiency of the Daudi cell is due to its lack of beta2 microglobulin.

Absorption, metabolism, and excretion of hydrochlorothiazide

14C-hydrochlorothiazide (hct) was administered orally (n=4) and iv (n = 2 to healthy subjects. The gastrointestinal absorption ranged between 60% and 80%, most of it took place in the duodenum and the upper jejunum. The radioactivity was eliminated mainly in the urine, while no sigificant biliary excretion was observed. Chromatographic analysis of the urinary radioactivity demonstrated that greater than 95% of the absorbed or injected 14C-hct was excreted unchanged. The radioactivity in plasma during the first 10 hr after oral administration declined with a fast phase but the levels of label thereafter suggested a slow phase. The existence of such a phase was verified in 1 subject given 75 mg hct orally. His plasma levels of hct (determined with gas-liquid chromatography) declined according to a 2-compartment model, the half-lives of the alpha-and beta-phases being 1.7 and 13.1 hr, respectively. Hct accumulated in the blood cells and the ratio between the radioactivity in cells and that in plasma averaged 3.5. The fate of a single dose of 14C-hct in 2 hypertensive patients treated with the drug chronically was similar to that in the healthy subjects. A third patient, who had slightly elevated serum creatinine, eliminated hct more slowly than the others. Like the healthy subjects, the patients eliminated hct to greater than 95% in unchanged form.

Comparison between two antibody populations in the EBV system: anti-MA versus neutralizing antibody activity

EBV-neutralizing antibody titers were determined in 11 sera derived from African Burkitt lymphoma or nasopharyngeal carcinoma patients and in the corresponding serum fractions retained above XM 100 Diaflo membranes after low pH treatment, and after recombination of the retained and passed fractions by neutralization of the acidified samples. They were compared with the corresponding antimembrane antigen (MA) titers in seven of the same sera. While all sera tested showed substantial increase of the anti-MA activity in the retained fraction, resulting in a significantly increased mean titer, EBV neutralizing activity did not change at all after identical treatment or changed only in a random fashion, resulting in stable mean titers. It is suggested that anti-MA and neutralizing antibodies are directed against at least partly different antigens on the virus.

On the fate of furosemide in man

35S-furosemide was administered orally (n=7) or i.v. (n=2) to healthy subjects. The average gastrointestinal uptake estimated by comparison of the urinary recovery of label and the areas under the plasma curves after the two routes of administration was 65%. The half life of radioactivity in the plasma after oral 35S-furosemide was 90 +/- 17 min (estimated on the slope between 2 and 6 h); the corresponding figure after 35S-furosemide i.v. was 47-53 min (slope 0.5-4 h). There was probably a slower phase after 4-6 h. Fractionation of labelled material in urine from two subjects demonstrated that approximately two thirds of the label recovered at 24 h had the same chromatographic properties as furosemide. A major part of the metabolite(s) was probably furosemide glucuronide. There was no evidence that 4-chloro-5-sulfamoylanthranilic acid was formed in man. The total urinary recovery of label (5-7 d) after oral and intravenous administration was 55.1 +/- 3.2 (mean +/- SD) and 82-84%, respectively. After 35S-furosemide i.v., 6-9% of the label was recovered in faeces, and it could not be accounted for solely by biliary excretion of furosemide.

Binding-site interaction of chlorthalidone and acetazolamide, two drugs transported by red blood cells

When 14C-chlorthalidone was administered orally to 2 healthy volunteers, the total recovery of radioactivity in urine (about 75 percent) and feces was close to 100 percent. Most of the label recovered in the blood was bound to the blood cells. When the procedure was repeated while the 2 subjects were receiving acetazolamide, the excretion of labeled material in urine and feces was essentially unchanged, but the blood cells contained less and the plasma more of the blood radioactivity. The half-life of the radioactivity in plasma and blood cells had decreased by about 65 percent. Intravenous administration of acetazolamide (single dose) to 2 other subjects who had received 14C-chlorthalidone orally resulted in a marked drop in the blood cell radioactivity, whereas that in plasma increased. The affinity of chlorthalidone for red blood cells was further evidenced on incubation of 14C-chlorthalidone with human blood. Of the incubated radioactivity, 94 percent to 99 percent was recovered in the erythrocytes. Preincubation of the blood samples with acetazolamide prior to the addition of 14C-chlorthalidone, as well as incubation of acetozolamide in blood samples previously incubated with 14C-chlorthalidone, demonstrated that acetazolamide is able to inhibit and to displace chlorthalidone from blood cells. There are several lines of evidence indicating that chlorthalidone is transported attached to the erythrocyte carbonic anhydrase.