Biomedical subjects

F Takei

Publications and source records attributed to F Takei.

At least 109 records · Page 6Linked to original sources

PubMed1985

Two monoclonal antibodies defining unique antigenic determinants on human B-lymphoma cells.

The non-Hodgkin's lymphomas are a clinically, morphologically, and immunologically heterogeneous group of diseases. Why lymphoma cells are unresponsive to normal regulatory growth controls and how they differ from normal lymphocytes are not well understood. In order to address these questions we have raised monoclonal antibodies to neoplastic B-cells. Two of these, LM-26 and LM-155, show a high degree of specificity for B-cell lymphomas. When tested by fluorescence activated cell sorter analysis, LM-26 reacted with 80% (18 of 23) of B-cell lymphomas freshly explanted from patients and LM-155 reacted with 20% (5 of 23). The antigenic determinant detected by LM-26 was also found to be present on four of seven neoplastic large cell B-lymphoma lines. LM-155 detected a determinant present on all seven of these lines. For neither monoclonal antibody was there any association between antibody reactivity and the morphological subtype of lymphoma examined or the type of cell surface immunoglobulin expressed. LM-155 reacted with one case of B-cell acute lymphoblastic leukemia. Neither antibody reacted with normal B-cell blasts, normal peripheral blood mononuclear or marrow cells, T-cell leukemias or lymphomas, or chronic lymphocytic leukemia cells. Lymphocytes from reactive lymphoid hyperplasias involving lymph nodes, spleen, peripheral blood, and lung were also negative for LM-26 and LM-155 binding or showed only a small percentage of cells positive (4-8%). Both monoclonals were unreactive with non-B-lymphoid neoplastic cell lines, nine of ten Epstein-Barr virus transformed B-cell lines, and cells freshly explanted from patients with cancers of diverse cellular origins. Fluorescence activated cell sorter analysis of the expression of the antigens defined by LM-26 and LM-155 on lymphoma cells and normal B-cell blasts suggests that they are not normal differentiation antigens associated with lymphocyte activation or proliferation. The highly restricted expression of detectable levels of antigens reactive with monoclonal antibodies LM-26 and LM-155 on non-Hodgkin's lymphoma cells suggests a possible relation to their neoplastic properties. From a practical viewpoint these monoclonals may prove useful in the diagnosis, classification, detection of residual disease, and treatment of the non-Hodgkin's lymphomas.

Antibodies, Monoclonal↗

PubMed1985

Inhibition of mixed lymphocyte response by a rat monoclonal antibody to a novel murine lymphocyte activation antigen (MALA-2).

A novel surface antigen expressed on activated and proliferating murine lymphocytes has been identified by a rat monoclonal antibody. The antigen, termed MALA-2, is also expressed on various lymphoid cell lines, but it is absent or present at very low densities on the majorities of unstimulated thymocytes and lymph node cells. Some cells in normal spleen and bone marrow seem to express the antigen at relatively high densities and they may represent proliferating cells in these tissues. MALA-2 has an apparent m.w. of 95,000 to 100,000 under both reducing and nonreducing conditions. The monoclonal antibody YN1/1.7 that reacts with this antigen partially inhibits Con A stimulation of spleen cells, but its inhibition of LPA stimulation is negligible. Furthermore, the antibody profoundly inhibits MLR. The inhibition of MLR by YN1/1.7 antibody is comparable to that caused by anti-transferrin receptor. The time course study suggests that the antibody may directly inhibit proliferating cell populations in MLR.

Animals↗

PubMed1984

Sequence polymorphisms in the 5'-upstream region of the fibroin H-chain gene in the silkworm, Bombyx mori.

DNA fragments containing the fibroin H-chain gene from two different strains of Bombyx mori, J-139 and Nd (2) were cloned into phage lambda Charon 4A. Comparison of the restriction sites in these cloned DNAs revealed that in addition to the known polymorphism in the region coding for the repetitive amino acid sequence of the fibroin H-chain [Manning and Gage, J. Biol. Chem. 255 (1980) 9451-9457], at least two other types of polymorphism were present, one around the 5' end of the structural gene, and the other in the far upstream region of the gene. Restriction sites around the 5' end of the gene were well conserved between these strains, but some heterogeneity, suggesting the presence of small insertions, deletions or base changes, was noted. In contrast, DNA sequences of the region 2-4 kb upstream from the 5' end of the gene were markedly different between these two strains, indicating that either a deletion or an insertion of a DNA sequence longer than 2 kb had occurred in this region. Comparison with several other strains suggested that the observed changes in the far-upstream region were unique to the Nd(2) strain.

Animals↗

PubMed1984

Reduced level of secretion and absence of subunit combination for the fibroin synthesized by a mutant silkworm, Nd(2).

Fibroin is normally composed of one H chain (350 kd) and one L chain (25 kd) which are connected by disulfide bond(s). However, the small amount of fibroin secreted into the lumen of the posterior silk gland of the Nd(2) (naked pupa) mutant does not contain L chain, although L chain mRNA is present and L chain is synthesized in the posterior silk gland cells of the mutant. In a hybrid silkworm, Nd(2)/Tamanashikasuri, where Tamanashikasuri is a normal producer of fibroin, L chain from the two alleles are distinguishable electrophoretically. It is demonstrated using this system that the L chain from the Nd(2) allele can combine normally with the H chain from Tamanashikasuri and the H-L complex is secreted normally. In another hybrid system, Nd(2)/J-131, where J-131 is a normal producer of fibroin, fibroin derived from the two alleles are distinguishable due to the different electrophoretic mobility of H chain. The fibroin derived from the J-131 allele is composed of H chain and L chain, while the fibroin derived from the Nd(2) allele is devoid of L chain, and its secretion is greatly reduced. We present evidence suggesting that the H chain derived from the Nd(2) allele is structurally abnormal and discuss how the H-L subunit structure is advantageous in the secretion of fibroin.

Alleles↗

PubMed1984

Unique surface phenotype of T cells in lymphoproliferative autoimmune MRL/Mp-lpr/lpr mice.

MRL/l mice, which carry the mutant gene lpr, develop massive T cell lymphoproliferation and an autoimmune syndrome. The surface antigen profile of MRL/l lymphocytes was analyzed with rat monoclonal antibodies. They included YE1/9.9, anti-transferrin receptor; YE1/7.1, which reacts with a population of proliferating immature T cells; and YE1/19.1, a newly identified antibody reactive with a surface antigen on EL-4 cells, which consists of two disulfide-bonded polypeptide chains, each of 115,000 m.w. Flow cytometric analysis of lymphocytes from the enlarged lymph nodes of MRL/1 mice showed the majority of them to be Lyt-1+, YE1/7.1+, YE1/19.1+, YE1/9.9-. In contrast, YE1/7.1 and YE1/19.1 antibodies did not significantly react with lymphocytes from the congenic MRL/n mice, which lack the lpr gene and do not develop lymphoproliferation. Lymphocytes from younger MRL/l mice, which have almost normal size lymph nodes, were also YE1/7.1-, YE1/19.1-. A small proportion of mitogen-stimulated MRL/n lymph node cells appeared to express these antigens at low densities, but it is not known whether they represent a unique cell population. Among the several lymphoid cell lines tested, only the T lymphoma line EL-4 had the Lyt-1+, YE1/7.1+, YE1/19.1+ phenotype. These results suggest that the lpr mutation induces the expansion of a unique T cell subset.

Aging↗

PubMed1984

A novel differentiation antigen on proliferating murine thymocytes identified by a rat monoclonal antibody.

A surface antigen on the mouse lymphoma cell line EL-4 has been identified by a rat monoclonal antibody. The antigen, YE1/7.1, is strongly expressed on at least two other T lymphoma cell lines, BW5147 and MBL-2, but not on several Thy-1-lymphoid cell lines. This antigen is not significantly expressed on normal adult thymocytes, spleen cells, bone marrow cells, or mitogen-activated T and B cells as tested by radioimmunoassay or fluorescence analysis using flow cytometry. Whether a small number (up to 5%) of very weakly positive cells in Con A-stimulated spleen cell populations represent a unique subpopulation is unknown. This antigen is, however, demonstrable on a subpopulation of fetal thymocytes as well as on mitogen-activated adult thymocytes. When adult thymocytes are separated by agglutination with peanut agglutinin (PNA) into PNA+ and PNA-, and stimulated with Con A in the presence of Con A culture supernatant, YE1/7.1 antigen is expressed on the majority of stimulated PNA+ cells but only weakly on a small proportion of PNA- cells. It therefore seems likely that the YE1/7.1 is a differentiation antigen expressed on a population of proliferating immature thymocytes. Immunoprecipitation of the antigen from the surface of iodinated EL-4 cells shows it to have an apparent m.w. of 60,000 under reducing and nonreducing conditions.

Aging↗

PubMed1984

MALA-1: a surface antigen expressed on activated murine T and B lymphocytes.

Detergent-solubilized plasma membranes of Con A-activated mouse spleen cells were absorbed with Sepharose-coupled rat antibodies against resting mouse lymphocytes. The unbound fraction was used to immunize a rat, and the immune spleen cells were fused with the rat myeloma Y3 . All seven rat monoclonal antibodies produced in this way strongly reacted with mitogen-activated spleen cells but only weakly or insignificantly with unstimulated spleen cells. One of the antibodies, YE3 /19.1, was studied in detail. The antibody strongly reacted with Con A- or LPS-stimulated spleen cells, but not significantly with normal adult thymocytes, spleen cells, or bone marrow cells. Unlike the transferrin receptor, which is expressed on virtually all dividing cells, the antigen defined by YE3 /19.1 was not detected on erythroblast-enriched populations or some non-T, non-B cell lines. Therefore, the antigen, termed MALA-1, seems to be specific for activated murine lymphocytes of the T and B cell lineages. Over 25% of normal adult lymph node cells were also found to express the antigen, although the antigen densities on lymph node cells were lower than those on mitogen-stimulated spleen cells. Kinetic studies of the expression of MALA-1 and the transferrin receptor on Con A-activated spleen T cells showed that both antigens are detectable within 24 hr of Con A stimulation. Although the density of the transferrin receptor on Con A blasts declined as the cell proliferation ceased, MALA-1 expression persisted. Immunoprecipitation of MALA-1 from surface-iodinated Con A blasts revealed its m.w. to be approximately 14,000 to 18,000.

Animals↗

PubMed1983

Localisation of metastatic carcinoma by a radiolabelled monoclonal antibody.

Rat monoclonal antibodies were prepared by immunising rats with human colorectal carcinoma cell membranes and fusing splenic lymphocytes with a rat myeloma. Hybridoma supernatants were screened by binding assays on membranes prepared from colorectal carcinoma tissue. One hybridoma supernatant, containing a monoclonal antibody with high binding activity on malignant compared to normal colon sections, was grown in large quantities in serum-free medium. After ammonium sulphate precipitation the antibody was purified by ion-exchange chromatography and labelled with 131I. Radiolabelled antibody was administered i.v. to 27 patients with colonic and other tumours. Scintigrams were obtained at 48 h. Computerised subtraction of the blood pool image revealed localised areas of uptake corresponding with areas of known disease in 13/16 patients with colorectal carcinoma and 3/4 patients with breast cancer.

Adult↗

PubMed1983

Two surface antigens expressed on proliferating mouse T lymphocytes defined by rat monoclonal antibodies.

A hybrid cell line resulting from the fusion of a Con A-activated normal mouse spleen cell and a transformed mouse T cell (EL-4BU) has been used to prepare and select rat monoclonal antibodies reactive with molecules expressed on the surface of proliferating, as opposed to resting, mouse T cells. In this report, the characterization of two such antigens identified in this way is described. One antigen is a membrane component common to mitogen-activated T and B cells, some bone marrow cells, and various transformed cell lines but is not detectable on either normal thymocytes or the majority of spleen cells by radioimmunoassay or FACS analysis. It has a m.w. of approximately 200,000 daltons under nonreducing conditions and 100,000 daltons under reducing conditions. Antibodies to this antigen precipitate cell-bound transferrin but do not react directly with transferrin itself. It would thus appear that the antigen is the transferrin receptor molecule. The second antigen is not detectable on normal thymocytes, spleen cells, bone marrow cells, or mitogen-stimulated spleen cells but is expressed at high levels on some transformed T cell lines. It, too, appears to be a dimer, with a m.w. of 95,000 daltons under nonreducing conditions, decreasing to 50,000 daltons under reducing conditions. Although the function of the 95,000-dalton antigen is not yet known, its lack of expression on adult T cell populations both before and after activation suggests either a short-lived role at a very early stage of T cell development and/or an association with T cell transformation.

Animals↗

PubMed1982

Biochemical characterization of H9/25, an allospecificity encoded by the Ly-6 region.

H9/25, an allospecificity encoded by the Ly-6 region, was biochemically characterized. It was sensitive to pepsin and heat treatment, but was resistant to periodate oxidation. Its apparent molecular weight was approximately 12000 daltons by gel filtration. The antigenic molecule was partially purified by gel filtration and antibody affinity chromatography. The partially purified antigen molecule was radioiodinated, immunoprecipitated with monoclonal antibody H9/25, and analyzed by SDS-polyacrylamide gel electrophoresis. The autoradiograph showed the molecular weight of H9/25 to be approximately 15000 daltons under reducing conditions. These results indicate that H9/25 is a protein with a single polypeptide chain of 12000-15000 daltons molecular weight, and the antigenic specificity is carried by a peptide but not a carbohydrate moiety.

Animals↗

PubMed1982

Immunohistochemical techniques in the early screening of monoclonal antibodies to human colonic epithelium.

Selected monoclonal antibodies (McAbs) isolated after immunization of rats with a human colonic carcinoma membrane preparation, have been screened on frozen and paraffin sections of colonic tissue, using immunohistochemical techniques, in order to provide additional information with regard to specificity and crossreactivity with normal tissues.Of 10 McAbs previously shown to bind to a colonic carcinoma membrane preparation in a radioimmunoassay, 7 show specific staining when tested by indirect immunofluorescence on crysotat sections of colonic tissue. Three of these 7 show activity on both normal and malignant colonic epithelium, and the remaining 4 stain normal epithelium, with little or no activity on malignant tissue. In the indirect immunofluorescent and immunoperoxidase techniques on paraffin sections of the same material, only 2 McAbs retain activity; one detects an antigen in colonic mucus, and the other recognises an antigen which is sparse on normal colonic epithelium and abundant on colonic tumours.We conclude that screening of McAbs on frozen tissue sections, using indirect immunofluorescence, is a useful adjunct to conventional screening methods, e.g. binding to membrane preparations and/or cell lines in a radioimmunoassay. These techniques distinguish McAbs with similar binding values in conventional assays, identify their activity on a wide range of normal and malignant tissues, demonstrate antigens that are lost or gained in malignant transformation and finally assist in the selection of McAbs for further extensive study before possible clinical use.

Animals↗

PubMed1982

Further analysis of the Ly-6 genetic region: isolation and characterization of cell lines with altered expression of Ly-6 antigens.

The identity, or close linkage, or a series of murine alloantigens encoded by the Ly-6 genetic region has been well documented. We have investigated the relationship between two component antigens, Ly-6.2 and H9/25, by generating and characterizing a number of variant cell lines which have altered antigen expression, isolated by chemical mutagenesis and immunoselection of BW5147 lymphoid cells. Cloned cell lines, selected by either antiserum, show loss of both antigens and also fail to express Thy-1, a further genetically linked, but unrelated determinant. The relevance of these findings to furthering understanding of the structure of the Ly-6 region and regulation of antigen expression is discussed.

Animals↗

PubMed1981

Ly-6 region regulates expression of multiple allospecificities.

The relationship between two alloantigens on mouse lymphocytes, that is Ly-6.2 and H9/25, which have previously been shown to have identical strain distribution patterns, was further investigated. Analysis of 39 (AKR x CBA) x CBA backcross progeny showed no segregation between these two antigens, indicating a close genetic linkage between them. Serological analysis showed that Ly-6.2 and H9/25 are differentially expressed on T-cell hybrid lines. Furthermore, cross-absorption of anti-Ly-6.2 serum with two cell lines revealed a heterogeneity among Ly-6 specificities. Semipurified H9/25 antigen failed to block anti-Ly-6.2 serum while anti-Ly-6.2 serum did not significantly block monoclonal antibody H9/25. These results suggest the presence of multiple allospecificities encoded for by the Ly-6 region.

Animals↗

PubMed1981

Use of a monoclonal antibody specifically non-reactive with T cells to delineate lymphocyte subpopulations.

Rat monoclonal antibody M1/69.16 reacts with a heat stable antigen of mouse commonly expressed in the majority of cell types in blood, spleen, bone marrow and thymus, including cells of erythroid, myeloid and lymphoid series. However, subpopulations of cells in lymphoid tissues can be identified which are non-reactive with this antibody using the fluorescence-activated cell sorter. All surface Ig positive cells seem to react with M1/69.16 while more than 96% of Ig negative cells in spleen and lymph nodes are M1/69.16 negative. Most cells (80%-90%) in the M1/69.16 negative populations in spleen lymph nodes and bone marrow express Thy-l. Thus, peripheral T cells are specifically non-reactive with this antibody. In contrast, approximately 95% of thymocytes react with M1/69.16, leaving a minor population which is negative. The negative population (5%) is enriched in cells expressing high amounts of H-2 antigen and those bearing H9/25 antigen which is specific for lymphocyte subsets, indicating that M1/69.16 negative thymocytes represent a specific subpopulation, possibly "mature' thymocytes.

Animals↗

PubMed1980

H 9/25 monoclonal antibody recognizes a new allospecificity of mouse lymphocyte subpopulations: strain and tissue distribution.

C3 H/He-mg mice were immunized with C57BL/10 (B10) spleen cells and the immune spleen cells were fused with BALB/c myeloma cells (NS1). One of the monoclonal antibodies (H9/25 antibody) produced by the hybrid cells was studied. It reacts with subpopulations of B10 lymphocytes as well as some lymphoid tumor lines including some of the Abelson virus-induced leukemias. The antigen recognized by H9/25 antibody is expressed on lymphocytes from all the B10 congeneic mice tested as well as some other strains of mice. No linkage between genes coding for the antigen and H-2 loci was found as judged by its presence on cells of the B10 strains regardless of H-2 type and the distribution of the antigen on Bailey recombinant inbred mice. The antigen is expressed on subpopulations of lymph node cells, spleen cells, thymocytes and bone marrow cells. The strain distribution of the H9/25 antigen seems to be identical to that of Ly-6, Ly-8 and Ala-1 antigens. However, the tissue distribution of the antigen recognized by H9/25 antibody, while similar to these alloantigens, is unique and the antigen may be distinct from the other alloantigens.

Animals↗

PubMed1980

Monoclonal antibody H9/25 reacts with functional subsets of T and B cells: killer, killer precursor and plaque-forming cells.

Monoclonal antibody (McAb) H9/25 has previously been shown to react with an alloantigen expressed on subpopulations of mouse lymphocytes. We here investigated the expression of the antigen (H9/25 Ag) on functional subsets of T and B cells. Lymphocytes were depleted of H9/25 Ag-bearing cells by complement-dependent cytolysis or by the affinity to immobilized McAb H9/25, and the residual immunological functions were tested. In these tests, killer T cells generated in mixed lymphocyte cultures and their precursors were found to express H9/25 Ag. In contrast, the activity and frequency of helper T cells specific to keyhole limpet hemocyanin carrier were not decreased by the depletion of H9/25 Ag-bearing cells. On the other hand, IgG and IgM anti-TNP plaque-forming cells were found to express H9/25 Ag, while it was not detected on unprimed B cells, as tested by using TNP-Ficoll and TNP-lipopolysaccharide. Only a small proportion of TNP memory B cells seemed to express the antigen. These results revealed significant differences between H9/25 Ag and other known alloantigens in the distribution among functional subsets of lymphocytes.

Animals↗

PubMed1980

Monoclonal anti-A from a hybrid-myeloma: evaluating as a blood grouping reagent.

A monoclonal anti-A antibody has been evaluated and found suitable for use as a potent routine ABO grouping reagent, without the use of additives. The IgM anti-A (MH2/6D4) is secreted into the tissue culture supernatant by a permanent line of cloned cells derived by fusion of anti-A producing spleen cells and a mouse myeloma cell line. This is a cost-effective reagent which should reduce production costs by over 50%. This reagent has the advantages inherent in monoclonal antibodies among them the availability of unlimited quantities of unvarying antibody of known properties.

ABO Blood-Group System↗

PubMed1978

Effect of adult thymectomy on tumour immunity in mice.

The effect of adult thymectomy in DBA/2J mice on the in vitro response to syngeneic tumour cells was investigated. Spleen cells from adult mice which had been thymectomized 8 weeks previously demonstrated a severely impaired primary cytotoxic response to P815 tumour cells, whereas their cytotoxic responses to allogeneic cells (C57BL/6) and to non-H-2 antigens (BALB/c), and their ability to form a primary antibody response to sheep red blood cells was unimpaired. Suppressor T cells, specific for P815 cells, appeared early in the thymuses of animals inoculated with P815 cells (between 4 and 8 days after tumour-cell injection). No differences in tumour growth between animals thymectomized as adults and sham-operated controls were observed, and thymectomized tumour-bearing animals had levels of specific suppressor cells in their lymph nodes equivalent to the levels found in untreated controls. Severely thymocyte-deprived animals which had been thymectomized, irradiated and reconstituted with either marrow or spleen cells 8 weeks before tumour implantation succumbed more rapidly to metastatic tumour than did control animals.

Animals↗