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Biomedical subjects

I Royston

Publications and source records attributed to I Royston.

At least 55 records · Page 3Linked to original sources
PubMed1985

Adult acute lymphoblastic leukemia phenotypes defined by monoclonal antibodies.

Pretreatment peripheral blood and/or bone marrow blasts from 90 adults with acute lymphoblastic leukemia (ALL) were analyzed as part of a prospective treatment protocol study. Specimens were tested by immunofluorescence cytofluorometry for reactivity with the following monoclonal antibodies (MoAbs): BA-1 (B cell antigen); T101, OKT11 (pan-T cell antigens [T]); 3A1 (T cell antigen); MCS-2 (myeloid antigen); J5 common ALL antigen (CALLA); BA4 (Ia antigen [Ia]); BA-2 (lymphohematopoietic antigen). Four major phenotypic groups were identified: B lineage ALL (BA-1+T-) (64%), T lineage ALL (T+BA-1-MCS-2-) (13%), unclassified ALL (BA-1-MCS-2-CALLA-T-) (9%) and myeloid antigen ALL (MCS-2+CALLA-T-) (7%). An additional group of patients, miscellaneous ALL (7%), was comprised of cases with unusual marker profiles. In B lineage ALL, all cases tested were Ia+MCS-2-, and the vast majority were CALLA+ (84%). In T lineage ALL, 42% expressed CALLA or Ia positivity. In unclassified ALL, the predominant phenotype was Ia+BA-2+. In myeloid antigen ALL, two of four tested were 3A1+ and all cases evaluated were BA-1-. Patients with myeloid antigen ALL were older (median age, 66 years) than patients in the other groups. The T lineage ALL group had higher leukocyte counts (median WBCs, 183,000/microL) and an increased incidence of anterior mediastinal mass at presentation. All patients received identical induction therapy. In CALLA+B lineage ALL, 30 of 46 (65%) achieved a complete remission. While the number of patients evaluated was small, 9 of 9 CALLA-B-lineage ALL and only two of six myeloid antigen ALL cases responded with a complete remission. The data suggest that these MoAbs are useful in the characterization of adult ALL.

Adult↗
PubMed1985

Kinetics of protein synthesis inactivation in human T-lymphocytes by selective monoclonal antibody-ricin conjugates.

Immunotoxins synthesized with the pan-T-cell monoclonal antibody T101 and ricin, acetylricin, or ricin A-chain have been compared. Native ricin was acetylated with N-acetylimidazole to block the galactose-binding site of the toxin B (binding)-chain. In the presence of lactose, both whole-ricin-containing immunotoxins were selectively cytotoxic but the ricin A-chain conjugate was less effective in blocking cellular protein synthesis. Immunotoxin-treated cells cultured in fresh growth medium exhibited no growth, declining viabilities, and no protein synthesis activity. Lymphocytes treated with T101:ricin or ricin did not form clusters or colonies when plated in 0.3% Bacto-agar. Ammonium chloride markedly enhanced the efficacy of T101:ricin and T101:ricin A-chain. Our results suggest that: (a) all immunotoxins were selectively cytotoxic; (b) in the presence of ammonium chloride the effectiveness of the T101:ricin A-chain conjugate approached that of T101:ricin; and (c) the toxin B-chain may facilitate conjugate internalization and/or processing.

Acetylation↗
PubMed1984

Immunoincompetence in cancer patients. Assessment by in vitro stimulation tests and quantification of lymphocyte subpopulations.

The authors performed a variety of lymphocyte-stimulation tests and quantified several lymphocyte subpopulations in 73 healthy controls and 72 patients with advanced cancer who were no longer receiving anticancer therapy. As a group, cancer patients had fewer lymphocytes and helper cells, but a greater proportion of suppressor cells and Ia+ cells than controls. The ratio of helper to suppressor cells was lower in the cancer group. Uptake of 125I-uridine was markedly depressed in cancer patients in the face of stimulation with various plant lectins, foreign lymphocytes, and varicella-zoster antigen. There was little correlation between any of the stimulation tests and any of the lymphocyte subpopulation proportions or numbers. The two tests that were most frequently abnormally low among the cancer patients were percent lymphocytes and number of helper cells (81% each). The most frequently abnormal functional assay in patients was pokeweed mitogen stimulation (59%). Three separate statistical methods selected the combination of percent lymphocytes, percent Ia+ cells, percent suppressor cells, number of helper cells, and pokeweed mitogen stimulation as being the best predictors of cancer/immunoincompetent status. This study confirms the breadth of immunoincompetence in advanced cancer patients as defined by in vitro techniques. A smaller battery of tests can be useful in monitoring the immune status of such patients, especially during therapy with proposed immune modulators.

Cell Membrane↗
PubMed1984

A human monoclonal antibody reactive with human prostate.

A human immunoglobulin M monoclonal antibody secreting hybridoma, termed MHG7, has been isolated and characterized for its reactivity against human prostate cells. Lymphocytes isolated from a regional draining lymph node of a patient with prostate carcinoma were fused with murine P3-NS1-Ag4-1 myeloma cells. Supernatants from the generated mouse-human somatic cell hybrids were first screened for human immunoglobulin production by an enzyme immunoassay. The identified human immunoglobulin-secreting hybridomas were expanded for further analysis and their supernatants screened by enzyme immunoassay against a panel of prostate cell lines. The human immunoglobulin M monoclonal antibody MHG7, in addition to reacting with prostate cell lines, also reacted with prostate carcinoma cells and benign prostatic hypertrophy cells on both frozen and paraffin embedded tissue sections. These data suggest that regional draining lymph nodes of prostate carcinoma patients can be used as a source of human lymphocytes for generating human immunoglobulin-secreting hybridomas reactive with human prostate cells.

Animals↗
PubMed1984

Therapy of chronic lymphocytic leukemia and cutaneous T-cell lymphoma with T101 monoclonal antibody.

The findings accompanying the administration of 50 intravenous courses of monoclonal antibody to human T-cell (T101) in eight patients, four with chronic lymphocytic leukemia and four with cutaneous T-cell lymphoma are reported. Infusion rates of 0.7 to 1 mg/min were associated with unacceptable toxicity in the presence of circulating target cells, but slower rates were well-tolerated. Immunofluorescence techniques confirmed that circulating cells did bind the antibody in vivo and were subsequently removed from the circulation. Modulation of the antigen on target cells in the bone marrow and skin has important implications for the schedule of administration of such antibodies, and points out the possible limitation of effector cell-mediated cytotoxicity at the tissue level. Production of anti-mouse antibodies resulted in neutralization of therapy in two patients with cutaneous T-cell lymphoma, and suggests that whether such an anti-mouse response is produced may be secondary to the underlying immune status of the patient or the amount of mouse protein to which immunocompetent cells are exposed. The relative specificity and efficacy of monoclonal antibody therapy is encouraging, but the limited clinical benefit and problems of modulation and anti-mouse antibody production underscore the need for continued research into passive therapy and suggest that cytotoxic conjugates may be of more clinical value.

Adult↗
PubMed1984

Induction of in vitro and in vivo antigenic modulation by the anti-human T-cell monoclonal antibody T101.

Because of its implications for the therapeutic application of monoclonal antibodies, we have studied antigenic modulation in vitro and in vivo in patients receiving T101 monoclonal antibody. Incubation of normal peripheral blood T-cells, chronic lymphocytic leukemia cells, and cutaneous T-cell lymphoma cells with an excess of T101 at 37 degrees induced modulation of the T65 antigen. When assayed by indirect immunofluorescence, a change in cellular reactivity with T101 was seen after 1 hr. After 24 hr, normal T-cells showed a 94 +/- 4% (S.D.) decrease in fluorescence, compared to an 82 +/- 6% decrease for chronic lymphocytic leukemia cells and a 56 +/- 4% decrease for cutaneous T-cell lymphoma cells. When T101 was removed from the culture, the cells reexpressed T65. Modulation was inhibited by cold temperatures, suggesting that it is energy dependent. Patients with chronic lymphocytic leukemia, cutaneous T-cell lymphoma, or T-cell lymphoma have received 24-hr infusions of 3 to 500 mg T101 in therapeutic trials. After infusion, in vivo binding of T101 was observed in 39 of 43 treatments not associated with endogenous host anti-T101 antibodies. T65-target cells were seen in all 39 treatments associated with in vivo bound T101, suggesting that modulation had occurred. When cultured in vitro for 24 hr, these cells reexpressed T65. In vivo, reexpression of T65 occurred following disappearance of the serum T101 titer. The extent and duration of in vivo modulation were related to both the T101 dose and the tumor burden. These data suggest that the rapid rate of antigenic modulation may prevent potential target cell destruction by antibody-mediated cytotoxicity. However, if the process of modulation involves internalization of the antibody:antigen complex, it would be an advantage for the use of cytotoxic immunoconjugates.

Antibodies, Monoclonal↗
PubMed1984

Alterations in cell surface phenotype of T- and B-cell chronic lymphocytic leukemia cells following in vitro differentiation by phorbol ester.

The phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) was used for the induction of in vitro differentiation in primary cultures of chronic lymphocytic leukemia cells to study its effects on B-cell antigens [surface IgG, HLA-DR, and the mouse erythrocyte receptor (MR)] and on T-cell antigens [T65 and Lyt-3 (sheep erythrocyte receptor)] found on these cells. Three distinct phenotypes were studied: 1) the common phenotype (slg+, HLA-DR+, MR+, T65+, Lyt-3-); 2) the T-cell phenotype (slg-, HLA-DR-, MR-, T65+, Lyt-3+); and 3) a unique phenotype (slg-, HLA-DR+, MR+, T65+, Lyt-3-). In both the common and unique phenotypes, TPA increased the expression of T65 and HLA-DR, decreased the formation of MR, and induced cytoplasmic immunoglobulin, but it did not induce Lyt-3. In the unique phenotype, TPA also induced surface immunoglobulin. These data suggest that both the common and unique phenotypes are derived from the same lineage, probably B-cell. In the T-cell phenotype, TPA increased the expression of T65 and Lyt-3, but it did not induce any B-cell antigens. These data suggest that the T-cell phenotype is derived from a T-cell lineage distinct from the two B-cell phenotypes.

Antigens, Surface↗
PubMed1984

Characterization of a monoclonal antibody that reacts with activated/proliferating cells and subsets of leukemia cells.

This report describes a murine IgG2A monoclonal antibody, called L22, derived by immunizations with an Epstein-Barr virus-negative large cell lymphoma B cell line. The antigen detected by L22 is not present on normal peripheral blood cells, but is present on cells stimulated by various mitogens. The proportion of L22+ cells correlates closely with blastogenesis and 125I-uridine uptake. L22 precipitates a 89,500-dalton antigen under reducing conditions, and a 180,000-dalton antigen under nonreducing conditions. The immunoreactivity, molecular weight of the antigen, sequential immunodepletion, and blocking experiments suggest that L22 reacts with the transferrin receptor, although it did not specifically block transferrin. L22 reacts with a variable proportion of cells from virtually all human myeloid, lymphoid, and solid tumor cell lines tested. Expression of the antigen is relatively constant within a given cell line and varies to only a limited extent with DNA content or cell cycle. The antigen has been identified on rare lymph node cells in certain reactive and malignant conditions. The antibody reacts with a variable number of peripheral blood cells in certain cases of myeloid and lymphoid leukemias, but does not react with peripheral lymphocytes from patients with inflammatory conditions. Its reactivity suggests possible utility in subclassification of leukemias, and perhaps in immunotherapy, in view of the limited reactivity with nonproliferating cells.

Antibodies, Monoclonal↗
PubMed1984

Lack of radioimmunodetection and complications associated with monoclonal anticarcinoembryonic antigen antibody cross-reactivity with an antigen on circulating cells.

Characterization of several high-affinity murine monoclonal anticarcinoembryonic antigen (CEA) antibodies suggested good specificity except for cross-reactivity with an antigen on granulocytes and erythrocytes which was different from the previously described normal cross-reacting antigen of granulocytes. In vivo studies in athymic mice using an indium conjugate of an anti-CEA monoclonal antibody (MoAb) revealed excellent specific uptake in colorectal carcinoma xenografts. Studies were conducted in humans to determine the limitations produced by the cross-reactivity with granulocytes and erythrocytes. Patients with metastatic colorectal cancer received 3 to 6 mg of anti-CEA MoAb over 10 min or 2 hr. In five of six trials, the MoAb infusion was associated with a 40 to 90% decrease in circulating granulocytes and systemic toxicity including fever, rigors, and emesis. One patient had no change in cell count and had no toxicity. Radionuclide scans with 111In-anti-CEA MoAb showed marked uptake in the spleen when cells were eliminated, and in the liver, especially when pretreatment CEA levels were high. Metastatic tumor sites failed to concentrate the isotope. This study emphasizes the potential limitations for radioimmunodetection and/or radioimmunotherapy imposed by reactivity with circulating cells, and suggests that certain toxic reactions associated with MoAb infusions are related to destruction of circulating cells rather than allergic reactions to mouse protein. It also emphasizes how variables such as dose and binding affinity of antibody, radioisotope used, and assessment at different observation points can obscure lack of antibody specificity.

Animals↗
PubMed1983

Membranous nephropathy associated with an unusual phenotype of chronic lymphocytic leukemia.

The nephrotic syndrome is uncommon in patients with chronic lymphocytic leukemia. When present, the most frequently documented cause is membranous nephropathy, although several other glomerular lesions have also been described. This report describes a patient with chronic lymphocytic leukemia of an unusual surface marker phenotype recently suggested to be associated with an increased incidence of proteinuria. Renal biopsy specimens demonstrated membranous glomerulonephritis. Immunofluorescence staining demonstrated glomerular deposition of IgG and C3, but not the human T-lymphocyte antigen, T65, which had been found on circulating leukemia cells.

Complement C3↗
PubMed1983

An enzyme immunofiltration assay useful for detecting human monoclonal antibody.

A microenzyme-linked immunoassay (EIA) utilizing an immunofiltration manifold has been developed which provides a rapid, simple, and sensitive method of detecting human monoclonal antibody class, concentration, and specificity. In this assay either whole cells or soluble antigens were immobilized on glass fiber filters followed by incubating with the test human hybridoma supernatant with subsequent analysis by EIA. A specially designed 96-chamber immunofiltration plate is employed which serves as both an incubation chamber and as a filtration manifold. The assay described is unique in that small volumes of human hybridoma supernatant are required, crude preparation of only a few target cells are needed, labile cell surface antigens are preserved and it can be completed in 3 h. This assay is well suited for the rapid screening of large numbers of human hybridoma supernatants.

Antibodies, Monoclonal↗
PubMed1983

UC 729-6, a human lymphoblastoid B-cell line useful for generating antibody-secreting human-human hybridomas.

UC 729-6, a 6-thioguanine-resistant human lymphoblastoid B-cell line, was fused with normal and malignant human lymphocytes. Parent UC 729-6 cells were diploid with a 21p+ marker chromosome, expressed surface and cytoplasmic IgM kappa, and doubled every 17 hr. The resulting human-human hybridomas were pseudotetraploid containing the 21p+ marker, doubled every 20-30 hr, and secreted 3-9 micrograms of human Ig per ml per 10(6) hybrid cells for greater than 9 months in continuous culture. Human Ig-secreting hybridomas were generated in 88% (14/16) of the fusions carried out and were cloned by limiting dilution (one cell per three wells) without the use of feeder layers. The mean fusion frequencies (number of wells, plated at 10(5) cells per well, showing hybrid growth per 10(6) lymphocytes fused) of UC 729-6 with normal lymphocytes ranged from 0.45 to 2.9 and with malignant B lymphocytes, from 3 to 10. Analysis of the human-human hybridomas derived from lymphocytes isolated from regional draining lymph nodes of cancer patients revealed several that secreted human monoclonal antibody that reacted by an enzyme immunoassay with some carcinoma cell lines but not with normal fibroblast cell lines. These data suggest that (i) UC 729-6 can be fused with human lymphocytes to generate stable human-human hybridomas, some of which secrete antibody reactive to human cell surface antigens, and (ii) UC 729-6 can be used to rescue Ig from nonsecretory malignant B cells and thereby allow for the production of anti-idiotype antibodies.

Antibodies, Monoclonal↗
PubMed1983

Chronic lymphocytic leukemia and other chronic lymphoid proliferations: surface marker phenotypes and clinical correlations.

A diagnosis of chronic lymphocytic leukemia (CLL) was made in 81 patients referred for peripheral blood lymphocyte typing (PBL). A retrospective review was undertaken to see if correlations existed between surface marker phenotype-determined subclasses and clinical features. Surface markers utilized were surface immunoglobulin (sIg), sheep erythrocyte receptor (E), 65,000-dalton human T lymphocyte antigen (T65), Ia antigen, and for sIg+ cells, heavy and light chains. All patients were Ia+. Cells of 70% of patients were sIg+ E- T65+ Ia+, and the clinical heterogeneity was that of classical CLL. Eight of the nine patients with sIg+ E- T65- Ia+ cells had a paraprotein. The sIg- E+ T65+ Ia+ phenotype represented classical T cell CLL. Three of the five patients in the sEg- E- T65+ Ia+ group had significant albuminuria, and two had nephrotic-range proteinuria. Use of additional monoclonal antibodies to B cell surface antigens should further subclassify CLL and other lymphoproliferative disorders. Interesting clinical correlations with certain phenotypic subclasses do exist, and further subclassification and long-term follow-up may yield correlations between phenotypes and prognosis.

Antigen-Antibody Complex↗
PubMed1983

In vivo immune restoration in advanced cancer patients after administration of thymosin fraction 5 or thymosin alpha 1.

Since patients with advanced cancer are usually immunodeficient, they might benefit from therapy with thymic hormones, which have an immunorestorative effect in immunosuppressed laboratory animals. We treated 14 patients with thymosin fraction 5 (TF5), and 14 patients with thymosin alpha 1 (TA1) over the dose ranges of 60-960 mg/m2 and 0.6-9.6 mg/m2, respectively. In addition to monitoring toxicity, we studied patients extensively using a variety of lymphocyte cell surface markers and in vitro functional assays, both before and following treatment. Approximately one-half of the in vitro tests were abnormal in the cancer patients prior to treatment. Overall, 28.4 and 18.3% of abnormal tests were improved following TA1 and TF5, respectively. On the other hand, 16% of normal tests became abnormal after therapy. Most of these responses occurred within 24-48 h and seldom persisted beyond 72 h. An optimum dose of TF5 was not readily identified, but 1.2 mg/m2 of TA1 was associated with substantial improvement in 46% of abnormal tests. Twelve of 14 cancer patients who received TF5 and 13 of 14 who received TA1 showed significant improvement in at least one in vitro test. Tumor responses were not seen, but the study suggested thymosin treatments would need to be repeated every 2-3 days to sustain an immune response. TF5 and TA1 are well tolerated as single i.m. injections, and have immunorestorative potential in cancer patients. Additional studies with repeated thymosin doses in more homogeneous cancer populations appear to be justified.

Female↗
PubMed1983

Characterization of a monoclonal antibody that reacts with an activation antigen on human B cells: reactions on mitogen-stimulated blood lymphocytes and cells of normal lymph nodes.

We describe a monoclonal antibody that reacts with human B-lymphoid cells. We have characterized the reactions of this antibody on normal blood lymphocytes, with and without pokeweed mitogen stimulation, bone marrow lymphocytes, and on frozen sections of normal lymph nodes. The antibody, B532, appears to recognize an activation antigen on human B cells. This activation antigen can apparently be induced both by infection with Epstein-Barr virus and by stimulation with antigens and mitogens, but it is lost on plasma cells. In normal lymph nodes, the antigen is confined to germinal center cells and some of the cells of the "mantle" that surrounds germinal centers. The antigen is not present on T cells.

Animals↗
PubMed1983

Chronic lymphocytic leukemia progenitor cells carry the antigens T65, BA-1, and Ia.

CLL B cells may be induced to form B-cell colonies in vitro. Colonies formed are monoclonal and appear to reflect the circulating malignant B-cell clone in vitro. Using hybridoma-produced monoclonal antibodies (MAB) and an in vitro B-cell colony assay, we have provided a characterization of the antigenic phenotype of the clonogenic CLL B cell. B-cell colony growth in both patients and normals was not altered by prior incubation with either MAB or complement (C') alone. CLL B-cell colony formation was markedly reduced after treatment with T101 and C', while normal colonies were unaffected (8 +/- 2 versus 107 +/- 10). None of the residual CLL B-cell colonies after T-101 and C' treatment reacted with T-101. However, BA-1 and la reactivity were still seen in residual CLL B-cell colonies following T-101 treatment. In contrast, a similar percentage reduction of B-cell colony growth was seen for both normals and CLL patients following treatment with BA-1 (76% versus 81%) and Q5/13 (89% versus 92%). These studies suggest that the CLL progenitor cell is characterized by the phenotype la+, BA-1+, T-101+. Better definition of the CLL progenitor cell has potential implications with regards to clinical utilization of MAB in the treatment of CLL.

Antibodies, Monoclonal↗