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Biomedical subjects

K Erb

Publications and source records attributed to K Erb.

At least 55 records · Page 3Linked to original sources

Review of studies on the clinical pharmacodynamics of cilazapril.

Several studies were performed to evaluate the degree of inhibition of angiotensin-converting enzyme (ACE) by an ACE inhibitor by assessing the blood pressure response to a continuous i.v. infusion of increasing doses of angiotensin I in healthy volunteers. We assessed pharmacokinetic and pharmacodynamic interactions of the ACE inhibitor cilazapril and the beta-blocker propranolol in healthy volunteers and patients with essential hypertension. We also evaluated the effect of cilazapril on aortic compliance in hypertension by pulse-wave velocity along the aorta. We showed that single oral doses of cilazapril 4 mg, captopril 25 mg, or enalapril 10 mg shifted the angiotensin I dose-effect curve to the right and determined a pharmacologic half-life of about 4 h for cilazapril. Increasing single oral doses (1.25, 3.75, 10, and 30 mg) of cilazapril reduced diastolic blood pressure dose-dependently and shifted the angiotensin I dose-response curves to the right. The dose representing 50% inhibition of ACE activity (apparent Ki dose) was about 0.6 mg 3 h after cilazapril administration. Cilazapril and propranolol did not exhibit significant pharmacokinetic interaction in healthy volunteers; each drug reduced diastolic and systolic blood pressure by about 7 mm Hg, and this was doubled by the combination. Monotherapy with each drug reduced blood pressure, and combined administration enhanced the antihypertensive effect. The reduction in cardiac output and the increase in total peripheral resistance induced by propranolol were attenuated by the cilazapril-propranolol combination.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

[Pharmacodynamic equivalence and clinical trial of a new fluorocarbon-free glycerol trinitrate pump spray with low ethanol content in comparison to a fluorocarbon-containing reference spray and a fluorocarbon-free pump spray with high ethanol content].

The pharmacodynamic equivalence of a fluorohydrocarbons-(FCH)-free glyceryl trinitrate (GTN, CAS 55-63-0)-containing pump spray with low ethanol content (Nitrolingual-Spray N; TL) versus a conventional FCH-containing GTN spray (Nitrolingual-Spray, R) as reference and a FCH-free GTN pump spray with high ethanol content (TH) was investigated by digital plethysmography (DPG) in a double-blinded, placebo-controlled (TL-matched placebo spray), randomized, period-balanced, 4-way cross-over design. Additionally the clinical tolerability (as perceived by the subjects and reported to the treatments-administrating investigator) was determined. The DPG-changes (cla; ratio of c-incisure and systolic a-wave) after the sublingual (s.l.) administration of 0.8 mg GTN of TL were biostatistically equivalent with R: the confidence intervals (CI) of the point estimates of the maximal decrease in cla (TL/R: 0.98, 90%-CI: 0.84 to 1.14) and the area-weighted average decrease in cla (TL/R: 0.97, 90%-CI: 0.80-1.16) were well in a 80-125% tolerance range. The time of occurrence of the maximal DPG-effect of TL was not different from R (distribution-free estimate of the difference TL-R: -2.25 min, 95%-CI: -9.5 min to 2 min). In contrast the maximal DPG-effect of TH after the s.l. administration of 0.8 mg GTN had a statistically significant earlier onset (TH-R: -6 min, 95%-CI: -9.5 min to -2 min) and a higher area-weighted average response (TH/R: 1.12, 90%-CI: 0.95 to 1.34). TH consistently caused an utterly unpleasant burning sensation in the mouth, thus this perceived local discomfort was distinctly different compared to all other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Sublingual↗

Tumor detection with 131I-labeled human monoclonal antibody COU-1 in patients with suspected colorectal carcinoma.

A major factor limiting the use of rodent monoclonal antibodies for diagnosis and therapy of cancer is the development of human anti-mouse immunoglobulin antibodies. Here we report a phase I/II immunodetection study of a human monoclonal antibody, COU-1, labeled with 131I. COU-1 is produced by a human-human hybridoma and recognizes a M(r) 43,000 cytokeratin-like protein strongly expressed by adenocarcinomas of the colon, breast, and ovary. Ten patients were given an i.v. infusion of 2 mg of antibody COU-1 labeled with 185 MBq of 131I. No adverse effects or toxicity were detected by conventional clinical tests nor by a complement activation assay for C3d. None of the patients developed antibodies against antibody COU-1 as determined by enzyme-linked immunosorbent assay and agglutination analysis. Tumor detection was successful in 7 of 9 cancer patients. The tenth patient proved to be a true negative. In several instances immunoscintigraphy gave additional or more correct information than conventional detection techniques. Tumors were most clearly outlined at days 5 and 7 after infusion. Primary colorectal carcinomas were detected by planar imaging in the cecum, ascending colon, and rectum with the smallest lesion measuring 3.0 cm in diameter. Immunoscintigraphy revealed multiple liver metastases in 1 of 3 patients. However, the livers of all 3 patients contained significantly more radioactivity (P < 0.005) than tumor-free livers of the other patients. Pharmacokinetics was evaluated in all patients. The clearance of 131I-labeled COU-1 from the circulation followed a triphasic pattern; an initial phase [t1/2 = 0.4 +/- 0.4 (SD) h] cleared 23% of the radioactivity followed by a rapid phase with a half-life of 13 +/- 3.8 h. The third phase (beta-phase) exhibited a half-life of 119 +/- 36 h, which is similar to the half-life reported for normal IgM. The human monoclonal antibody COU-1 directed against a predominantly intracellular cancer-associated antigen does not produce toxicity or induce antibody formation and seems to be a promising agent for detecting tumors with immunoscintigraphy.

Animals↗

Preparation of antigen-binding monomeric and half-monomeric fragments from human monoclonal IgM antibodies against colorectal cancer-associated antigens.

The large size of human IgM monoclonal antibodies (MAbs) may impede the tumor-localizing capacity. A procedure is described for the preparation of antigen-binding monomeric (IgMm) and half-monomeric (IgM1/2m) fragments from two human IgM MAbs, COU-1 and D4213. The fragments retained binding activity against colon carcinoma. Six different reducing reagents (dithiothreitol, 2-mercaptoethanol, 2-mercaptoethylamine, L-cysteine, metabisulphite, ascorbic acid) were investigated over a range of concentrations, pHs, and incubation periods. The reduced IgM preparations were alkylated with iodoacetamide and fractionated by high-performance gel permeation chromatography. The fractions were directly collected on ELISA plates coated with extracts of colon cancer cells. Antigen-binding IgMm and IgM1/2m fragments were obtained after treatment with mercaptoethanol, mercaptoethylamine, metabisulphite, and cysteine. IgMm and IgM1/2m fragments were also obtained after dithiothreitol treatment. These fragments were, however, nonreactive. The pH during the reduction was important for optimal yields of the fragments. The fragments obtained with 2-mercaptoethanol and mercaptoethylamine were most effective in binding to the cancer cell extract. The association constants per binding site for intact, monomeric, and half-monomeric COU-1 were by competitive inhibition assays estimated at 1.5 x 10(8) M-1, 3.1 x 10(8) M-1 and 4.0 x 10(6) M-1, respectively. The reduction of human IgM MAbs to IgMm and IgM1/2m fragments may facilitate the tumor localization when these are used in the diagnosis and therapy of cancer patients.

Alkylation↗

Tumour localization and pharmacokinetics of iodine-125 human monoclonal IgM antibody (COU-1) and its monomeric and half-monomeric fragments analysed in nude mice grafted with human tumour.

Human monoclonal IgM antibodies reactive with cancer-associated antigens may not have the optimal imaging capability due to their large size. Fragmentation of human IgM is less than straight-forward due to the loss of immunoreactivity. From the human monoclonal IgM antibody COU-1 we have prepared monomeric and half-monomeric fragments, which retain the ability to bind to colon cancer cells in vitro. The pharmacokinetics and tumour localization were evaluated in nude mice bearing human colon adenocarcinoma and human melanoma grafts. Faster clearance from the circulation was seen for the smaller half-monomeric fragment with a half-life (rapid phase/slow phase) of 2 h/16 h compared with the intact antibody, 4 h/25 h, and the monomeric fragment, 3 h/27 h. Intact COU-1 as well as the fragments accumulated in the colon tumour graft. Higher amounts of radioactivity were found in the colon tumour as compared to normal organs for intact COU-1 at days 4 and 6, for the monomeric fragment at day 4, and for the half-monomeric fragment at day 2 after injection. This investigation demonstrates the favourable biodistribution of the half monomeric COU-1 fragment. The fast clearance of this fragment resulted in a tumour-to-muscle ratio as high as 22 on day 2 after injection. Also, only this fragment gave a positive tumour-to-blood ratio. Normal IgM and its fragments were used as controls. Radioimmunoscintigraphy demonstrated the colon tumour discriminatory properties of each of the three iodine-labelled antibody preparations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

Characterization of a human-human hybridoma antibody, C-OU1, directed against a colon tumor-associated antigen.

The human hybridoma cell line, B9165, was obtained after fusion of lymphocytes from lymph nodes draining the tumor region in a patient with adenocarcinoma of the colon with the human B-lymphoblastoid cell line WI-L2-729-HF2 (729-HF2). B9165 secretes the human monoclonal antibody, C-OU1 (IgM, kappa). Immunocytochemical and immunohistochemical analysis showed that the antibody bound to a differentiation antigen. Electron microscopy of colonic adenocarcinoma cells, intact tumor and colonic epithelium by the immunogold technique demonstrated that the C-OU1 antibody reacted with a molecule associated with areas of disruption of the intermediate filaments in the cytoplasm of the tumor cells. No reaction was seen with intermediate filaments in normal colonic epithelium. The molecular weight of the antigen was shown to be 43 Kda by SDS-PAGE and Western blotting of tumor extracts, and isoelectric focusing of sonicated extracts demonstrated reaction with molecular species of pI 5.4-6.2. These findings suggest that the C-OU1 antigen is a modified cytokeratin 18. The B9165 cell line has proved to be quite stable, and the antibody is of potential clinical value. Its usefulness for localizing tumors in patients is being investigated.

Antibodies, Monoclonal↗

Evaluation of procedures for the fixation and processing of human tissue for immunohistochemical analysis of human monoclonal antibodies.

Preliminary investigations suggested the importance of an evaluation of different tissue preparation methods frequently used for immunohistochemical analysis of human or murine monoclonal antibodies on human tissue. Colon adenocarcinomas and adjacent morphologically normal colon epithelia were analyzed with an indirect immunoperoxidase technique. Duplicate tissue specimens were (1) snap frozen and fixed in acetone, (2) formalin fixed and paraffin embedded, with or (3) without ensuing treatment with pronase, or (4) alcohol fixed and paraffin embedded. Three different human monoclonal anti-colon cancer IgM antibodies, COU-1, D4213, and F10279, were used in the present study. Endogenous immunoglobulin and the secretory-component-mediated IgG binding were blocked on frozen sections with Fab' anti-IgM and anti-SC antibody. Bound monoclonal antibody was detected with horseradish peroxidase-anti-IgM. COU-1 was found to stain frozen sections of all 25 cancer and adjacent normal colon epithelia. In contrast, on formalin-fixed, paraffin-embedded tissue, only 80% (20/25) of the colon cancer and 44% (11/25) of the adjacent normal colon epithelia were positive. After treatment of the formalin-fixed sections with pronase, all cancers and normal adjacent epithelia were stained, but the cancer cells were more intensely stained than the normal colon epithelial cells. On alcohol-fixed tissues, intense staining was found in all the colon carcinomas analyzed, whereas no staining was found of the adjacent normal colon epithelia, except for a few cells in some of the sections investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

Antigens recognized by two human monoclonal IgM anticolon cancer antibodies, 16.88 and C-OU1 (B9165).

We have compared by SDS-PAGE Western blotting the molecules detected by two human monoclonal antibodies, C-OU1 and 16.88. The antibodies have previously been shown to detect a cytoplasmatic antigen with an Mr of 43 kD present in colon adenocarcinoma cell lines and in colon cancer tissues. We now demonstrate that these antibodies differ significantly in their fine specificity, resulting in a quite dissimilar tumor selectivity. The antibody 16.88, in addition to reactivity with the 43-kD molecule, also recognizes a 190-kD molecule present both in melanoma cells and in cells previously reported as 16.88 antigen positive. The 16.88 antibody does not detect a 43-kD molecule in extracts of melanoma cells. The 190-kD component was not detectable in hepatoma or mamma carcinoma cells, both of which showed presence of the 43-kD molecule. The C-OU1 antibody shows no reactivity with the 190-kD molecule in any of the cells tested or with other proteins in melanoma cells. Radiolabeled 16.88 antibody shows better localization to melanoma cancer than to colon cancer xenograft transplanted onto nude mice. These findings indicate the presence of a tumor-associated antigen not previously described and have obvious implications for potential clinical uses of the antibodies.

Animals↗

A method for blocking antigen-independent binding of human IgM to frozen tissue sections when screening human hybridoma antibodies.

Using an indirect immunoperoxidase technique antigen independent binding of both human monoclonal and polyclonal IgM was found to a wide range of frozen sections of normal and malignant human glandular epithelia. Identical binding was found using dimeric human IgA (dIgA), whereas no binding was found with monomeric human IgA or human IgG. Secretory component (SC) was found to be the component in these tissues mediating antigen-independent binding of human IgM and dIgA antibodies. A method for the blocking of this antigen-independent binding of human IgM and dIgA was evaluated. Frozen sections of tissues containing SC were blocked with antibody to endogenous immunoglobulin and preincubated with rabbit anti-secretory component antibody (anti-SC) before applying the human monoclonal antibody. This treatment blocked the binding of control polyclonal and monoclonal human IgM to sections of SC-containing tissues such as respiratory and colonic epithelia. The influence of anti-SC on the binding of dIgA could not be established due to interactions between the anti-SC antibody and the IgA preparation. Using this method human hybridoma supernatants containing IgM could be readily screened for reactivity with frozen tissue sections from patients with colo-rectal cancer. This approach is recommended for the screening of human IgM monoclonal antibodies on frozen human tissue sections.

Animals↗

Immunohistochemical analysis of the binding of human IgM to secretory component present in normal adult colon epithelia, but not in colon cancer and fetal colon epithelia.

We have analysed the binding of human IgM to fetal, normal adult and malignant colo-rectal tissues. Using an indirect immunoperoxidase technique on sections of frozen tissues human IgM binds to all normal adult colo-rectal epithelia (n = 15) tested. By contrast, 9 out of 25 colo-rectal adenocarcinomas were negative, and in the remaining 16 the staining reaction varied from staining of all the cancer areas to focal staining of a few areas. Human IgM did not bind to 14 samples of fetal intestinal epithelium (gestational age of 6-14 weeks). The binding of IgM was found to be mediated by secretory component (SC) as anti-SC antibody (anti-SC) showed a similar staining pattern as IgM and the IgM binding could be blocked by anti-SC. SC was also demonstrated in glandular epithelia of sections of all normal breast epithelia but only in 10 out of 15 breast adenocarcinomas. The loss of IgM binding and SC could not be correlated to the morphology of the adenocarcinomas. The observations on fetal, normal adult and malignant tissue suggest that IgM binding and SC may be gradually lost during dedifferentiation of normal cells, to malignant colo-rectal or breast epithelia.

Adenocarcinoma↗

Human-human hybridoma producing monoclonal antibodies against colorectal cancer-associated antigens.

Lymphocytes from lymph nodes draining the tumor region in patients with colorectal cancer were fused with two different human B-lymphoblastoid cell lines, LICR-LON-HMy-2 (HMy-2) and WI-L2-729-HF2 (729-HF2), to generate hybridomas synthesizing antibodies reacting with tumor-associated antigens. In this way 220 hybridomas were obtained which produce antibody reacting with colon cancer cells. All established clones produced IgM. Four human monoclonal antibodies have been further analyzed. The cell lines producing these antibodies are all hybrids based on DNA analysis. Three of the antibodies (G4146, B9165 and D4213) showed binding to differentiation antigens by immunocytochemical analysis on different cancer cell lines and normal human leucocytes and by immunohistochemical analysis on sections of frozen malignant and normal tissues, while the fourth (F11348) showed a reaction with all cells and tissues tested. Western blots of tumor extracts showed binding of G4146 to two components from colon cancer cells with Mr of 59 K and 61 K, while B9165 bound to a 43 K component and F11348 to several components with Mr from 30 to 200K. D4213 showed no binding in this analysis. The results obtained demonstrate the successful application of hybridoma technology to produce human monoclonals with reactivity to differentiation antigens.

Antibodies, Monoclonal↗

Influence of the angiotensin converting enzyme inhibitor cilazapril, the beta-blocker propranolol and their combination on haemodynamics in hypertension.

This study compared the antihypertensive effects and the haemodynamic mechanisms of action of an angiotensin converting enzyme (ACE) inhibitor, a beta-blocker and the combination of both in patients with mild to severe hypertension. After a placebo run-in period of 2 weeks, patients were treated for 3 weeks with each of the following: cilazapril (2.5 mg daily) and propranolol (120 mg daily), in a randomized sequence, and thereafter a combination of the two drugs. Blood pressure, cardiac output (measured by Doppler ultrasound) and total peripheral resistance (TPR) in a sitting position at rest were determined. One patient out of 18 was withdrawn in the cilazapril phase. Both monotherapies yielded significant and similar reductions of diastolic blood pressure (average -10 mmHg). Cardiac output and TPR showed opposite effects. Cardiac output was lower with the beta-blocker than with the ACE inhibitor (3.4 versus 4.5 l.min-1), while TPR behaved conversely (2646 versus 2005 dyne.s.cm-5). The combination of both drugs lowered diastolic blood pressure significantly more than the monotherapies (average -20 mmHg); the haemodynamic effects of the monotherapies were attenuated by the combination (cardiac output = 3.7 l.min-1; TPR = 2170 dyne.s.cm-5). A sitting diastolic blood pressure of less than or equal to 90 mmHg could be achieved in six out of 17 patients with propranolol alone, in eight out of 18 with cilazapril alone, and in 14 out of 17 with the coadministration of both drugs. The combination was better tolerated subjectively than the beta-blocker alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Haemodynamic and hormonal effects of cilazapril in comparison with propranolol in healthy subjects and in hypertensive patients.

1. The purpose of the present studies was to compare the pharmacodynamic profile of the new ACE inhibitor cilazapril with the beta-adrenoceptor antagonist propranolol in healthy subjects and in hypertensive patients. 2. Hormonal and haemodynamic responses at rest and after pharmacological interventions with angiotensin I and isoprenaline were investigated in six healthy volunteers following a 1 week treatment with placebo, propranolol (120 mg day-1) and cilazapril (2.5 mg day-1) in a double-blind cross over design with a wash-out period of 1 week between the different treatments. 3. Cilazapril induced a pronounced increase of plasma renin activity and angiotensin I concentrations, whereas after propranolol both parameters decreased. After both compounds slight decreases in angiotensin II concentrations were found. After the pharmacological challenges with angiotensin I and isoprenaline specific effects of the ACE inhibitor and beta-adrenoceptor blocker were found respectively. 4. Seventeen hypertensive patients received after a 2 week placebo period in random order cilazapril (2.5 mg day-1) or propranolol (120 mg day-1) for 3 weeks. A cross over design switched the patients to the other treatment. On the last day of each treatment period blood pressure, heart rate, cardiac output and total peripheral resistance were determined at rest and during handgrip test. In addition, bicycle exercise test was done and blood lactate concentrations were determined. 5. At rest blood pressure was lowered by both drugs, but total peripheral resistance increased after propranolol and decreased after cilazapril. After hand grip test, blood pressure was lowered after both drugs, but peripheral resistance decreased only after cilazapril.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Pharmacokinetic and pharmacodynamic interactions between the ACE inhibitor cilazapril and beta-adrenoceptor antagonist propranolol in healthy subjects and in hypertensive patients.

1. Six healthy subjects received cilazapril (2.5 mg once daily), propranolol (120 mg once daily), the combination of both and placebo for a period of 1 week each (wash-out phase 1 week). 2. Propranolol and cilazapril reduced systolic and diastolic blood pressure (BP) by 7 mm Hg at peak when compared with placebo. However after the combination, this reduction was more than doubled (18 mm Hg) and lasted longer. 3. There was a trend to lower and later peak concentrations for both drugs after administration of the combination. No clinically relevant pharmacokinetic interactions between cilazapril and propranolol were found. 4. The effects on blood pressure were confirmed in hypertensive patients (BP diastolic greater than 95 mm Hg). Thirteen patients were randomly allocated cilazapril (2.5 mg day-1) or propranolol (120 mg day-1] as part of a cross-over design. This was then followed by the combination. All treatment periods were of 3 weeks duration and all measurements were done 2 h after drug administration. 5. Cilazapril lowered the median sitting diastolic BP by 8 mm Hg, and propranolol by 9 mm Hg, whereas the combination reduced the diastolic BP by 19 mm Hg. 6. The results of these studies, attempting to elucidate drug-drug interactions, showed that combined use of propranolol and cilazapril resulted in a more pronounced and longer lasting blood pressure reduction, in healthy subjects and in patients with hypertension.

Adult↗

Curing human hybridomas infected with Mycoplasma hyorhinis.

Tiamuline and minocycline were evaluated for the treatment of an IgM producing human-human hybridoma cell line infected with Mycoplasma hyorhinis. Tiamuline was used at a concentration of 10 micrograms/ml culture medium and minocycline at a concentration of 5 micrograms/ml culture medium. Both antibiotics were found to eliminate mycoplasma infection over a treatment period of 3 weeks, and the hybridoma cell line remained mycoplasma-free for 6 months after treatment. Tiamuline had no effect on either cell growth or IgM secretion. Whereas treatment with minocycline alternated the cell proliferation and completely inhibited IgM secretion. This effect on cell function was found to be reversible since both cell growth and IgM secretion returned to normal 1 week after the minocycline had been removed. Tiamuline as well as minocycline may be recommended for the treatment of human hybridomas infected with mycoplasma.

Cell Division↗

Alkaline phosphatase which lacks its own signal sequence becomes enzymatically active when fused to N-terminal sequences of Escherichia coli haemolysin (HlyA).

Fusion of the alkaline phosphatase gene (phoA) which lacks its own signal peptide sequence to the N-terminal region of hlyA, the structural gene for Escherichia coli haemolysin, leads to active alkaline phosphatase (AP). AP activity depends on the length of the N-terminal region of hlyA. An optimum is reached when 100-200 amino acids of HlyA are fused to PhoA but fusion of as little as 13 amino acids of HlyA to PhoA is sufficient to yield appreciable AP activity. When cells are treated with lysozyme most of the AP activity is found associated with the membrane fraction but a substantial amount is also found in the soluble fraction, most of which may represent a periplasmic pool of AP. The soluble portion of AP activity is significantly increased when the cells are disrupted by ultrasonication, which indicates that the fusion proteins are only loosely associated with the membrane and that large parts are already located on the outside of the cytoplasmic membrane. The expected fusion proteins were identified in the soluble and the membrane fractions and their amounts in these fractions correlated well with AP activity.

Alkaline Phosphatase↗

A method for the blocking of endogenous immunoglobulin on frozen tissue sections in the screening of human hybridoma antibody in culture supernatants.

Endogenous immunoglobulin in tissue sections pose a problem in immuno-histochemical techniques employing homologous antibody as primary reagents and enzyme-labelled anti-immunoglobulin for the development. A method for the blocking of endogenous immunoglobulin in human tissue sections by incubation with monomeric pepsin fragments (Fab') of rabbit anti-human immunoglobulin before applying monoclonal antibody was evaluated for the screening of human monoclonal antibody. It was initially demonstrated that Fab' rabbit anti-human IgM and anti-IgG could block endogenous immunoglobulin in human IgM and IgG producing tumors thereby abolishing the binding of subsequently applied peroxidase-labelled anti-IgM or anti-IgG. Frozen sections of human colo-rectal adenocarcinomas show a variable background staining caused by the endogenous immunoglobulin. The background completely disappeared in the IgM system by preincubation with Fab' anti-IgM while the background was clearly reduced but not abolished in the IgG system. A human hybridoma supernatant containing IgM reactive with colo-rectal adenocarcinoma could easily be screened on frozen sections using this method. This approach should be generally useful for the screening of human antibody on human tissue sections.

Antibodies, Monoclonal↗

Human-human hybridomas generated with lymphocytes from patients with colorectal cancer.

Human-human hybridoma technology was used to produce human monoclonal antibodies with reactivity to colorectal cancer antigens. Two different B-lymphoma cell lines were fused with lymphocytes obtained from mesenteric lymph nodes from colorectal cancer patients. The fusion frequency was 11% with LICR-LON-HMy-2. Out of 294 growing hybridomas 26 secreted antibodies reacting with epitopes on cultured colon adenocarcinoma cells. Only one (D4213) was established and has now been in culture for 1.5 years. D4213 antibody shows a strong reaction with colon cancer tissue compared with normal colon epithelium. Using W1-L2-729-HF2 the fusion frequency was about 50%. Of 2,487 hybridomas 499 produced immunoglobulin and 44 of these reacted with colon cancer tissues or cultured cancer cells. One of the established hybridomas produces antibody reacting with cancer cell membrane antigens, and on immunoblotting a number of components were stained. The antibody from the other hybridomas reacts with cytoplasmatic antigens, and only one of these showed reactivity in immunoblotting where it bound to a component with Mr of about 60K.

Antibodies, Monoclonal↗