Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A human leukemia-associated differentiation antigen has been identified by a monoclonal antibody (A12) raised to the lymphoblastoid cell line NALM-1. The A12 antigen was expressed on the surface of leukemic cells from patients with common acute lymphoblastic leukemia (c-ALL) as well as on cells of the hematopoietic cell lines NALM-1, Reh-6, Raji, Daudi, CEM, and 8402 as determined by an antibody-binding radioimmunoassay, as well as by indirect immunofluorescence and FACS analysis. This antigen was not detected on normal blood lymphocytes, normal bone-marrow cells or leukemic cells from patients with acute myeloid leukemia (AML). The A12 antigen had an apparent molecular weight of 100 kD as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and appeared to be related to if not identical with the acute lymphoblastic leukemia antigen CALLA described by others. Cross-blocking experiments indicated that preincubation of NALM-1 cells with antibody A12 or J5 (anti-CALLA) could block subsequent binding of 125I-labeled A12 and J5 antibody. These results suggest that the two monoclonal antibodies recognize identical or closely located antigenic sites. The surface membrane expression of A12 antigen in NALM-1 cells was modulated when the cells were cultured in the presence of A12 antibody. Under these conditions, the expression of Ia antigens was unaffected. Re-expression of A12 antigen occurred within 24 h after transfer of the modulated cells into medium devoid of monoclonal antibody.
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PMID:Characterization of a monoclonal antibody (A12) that defines a human acute lymphoblastic leukemia-associated differentiation antigen. 620 73

beta t, the 12,000 molecular weight polypeptide originally found in HTA 1, a thymus specific differentiation antigen, is a major labelled component of surface iodinated HLA-A,B,C purified by monoclonal antibody W6/32 from the T leukaemia cell line Molt 4. A correlation between the amount of beta t in HLA-A,B,C and the level of HTA 1 expression in Molt 4 and variants derived from it was established. The presence of beta t in the HLA-A,B,C complexes is not due to cross contamination with HTA 1. However, analysis of a large scale HLA-A,B,C preparation using Coomassie blue staining shows that, under conditions of surface iodination, beta t is over-represented by a factor of about 100 times relative to beta 2 microglobulin. The significance of beta t as a minor component of HLA-A,B,C in thymus derived cells remains uncertain.
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PMID:Is beta t a component of HLA-A,B,C in thymus derived cells? 620 26

A new cell surface antigen of the mouse related to xenotropic murine leukemia virus (MuLV) is described. The antigen, designated G(erld), is defined by cytotoxic tests with the B6-x-ray-induced ERLD and naturally occurring antibody. G(erld) is distinct from all previously defined cell surface antigens. Monoclonal antibody with the same specificity has been developed. Inbred mouse strains are classified as G(erld)+ or G(erld)- according to the presence of absence of the antigen on lymphoid cells. G(erld)+ strains differ with regard to quantitative expression of G(erld) on normal thymocytes. The emergence of G(erld)+ tumors in G(erld)- strains indicates the presence of genes coding for the antigen even in strains not normally expressing the antigen. G(erld) has the characteristic of a differentiation antigen in normal mice. In G(erld)+ strains, high levels of the antigen are found on thymocytes with lower levels being detected on cells of spleen, lymph nodes and bone marrow. No G(erld) was detected in brain or kidney or on erythrocytes. The segregation ratios for G(erld) expression on thymocytes in backcross and F2 mice of crosses between G(erld)+ (B6, 129, and B6-Gix+) and G(erld)- (BALB/c) strains suggest that G(erld) expression is controlled by a single locus in B6, by two unlinked loci in 129, and by three unlinked loci in B6-Gix+ mice. Induction of the antigen by MuLV infection of permissive cells in vitro indicates that G(erld) is closely related to xenotropic and dualtropic MuLV; all xenotropic and dualtropic MuLV tested induced the antigen, whereas the majority of ecotropic and the two amphotropic MuLV failed to do so. As dualtropic MuLV are thought to be recombinants between ecotropic and xenotropic MuLV sequences, G(erld) coding by dualtropic MuLV may signify the contribution of the xenotropic part in the recombinational event. Serological and biochemical characterization indicates that G(erld) is related to the gp 70 component of the MuLV envelope. The relation of G(erld) to the previously defined gp 70-related cell surface antigens (Gix, G(rada), and G(aksl2) is discussed, particularly with regard to their characteristics as differentiation antigens, the genetic origin of dualtropic MuLV, and the leukemogenicity of MuLV.
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PMID:A cell surface antigen of the mouse related to xenotropic MuLv defined by naturally occurring antibody and monoclonal antibody. Relation to Gix G(rada1), G(aksl2) systems of MuLV-related antigens. 626 31

The human T-cell leukaemia and differentiation antigen HTA 1 is defined by the monoclonal antibody NA1/34 (ref. 1) and also recognized by the monoclonal antibody OKT6. Like class I products of the human major histocompatibility complex, it has a glycosylated heavy (alpha) chain of approximately 45-50,000 molecular weight (MW) in non-covalent association with beta 2-microglobulin (beta 2m) (MW 11,900). A particular feature of HTA 1 is the presence in significant amounts of an additional beta 2m-like subunit, called beta t (refs 3, 4). Top facilitate biochemical studies we have prepared a high HTA 1 expressor variant (NH17) of the human thymoma line MOLT-4. The N-terminal amino acid sequence of the beta t purified from this cell line was shown to be indistinguishable from that of bovine beta 2m. Further, beta t was present when the cells were grown in medium containing fetal calf serum (FCS), but absent from cells grown with human serum (HuS). We show here that addition of human and bovine beta 2m to MOLT-4 and NH17 cells grown in serum-free medium produces a significant elevation of HTA 1 antigen expression, providing evidence for a regulatory or stabilizing function for the exchange of extracellular beta 2m with a cell-surface antigen.
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PMID:Serum beta 2-microglobulin binds to a T-cell differentiation antigen and increases its expression. 642 30

The protein defined by the anti-p19 monoclonal antibody (raised against a 19-kilodalton protein from human T leukemia virus) and normally acquired during the ontogenesis of the human thymic epithelium was studied by indirect immunofluorescence in thymomas and thymic hyperplasias. Hyperplastic (and involuted) thymuses from patients with myasthenia gravis exhibited a clear-cut expression of this differentiation antigen exclusively in epithelial cells, thus qualitatively similar to what was observed in the normal thymus. In thymoma epithelial cells, however, this expression was strongly altered: in the 12 malignant thymomas studied, no anti-p19 reactivity was found. In the four benign cases, a variable number of epithelial cells expressed this antigen. These results suggest that the differentiation antigen of the human thymic epithelium defined by the anti-p19 monoclonal antibody is lost during the malignant transformation occurring in thymomas. Furthermore, this monoclonal antibody provides an additional tool for the study of the degree of dedifferentiation of thymomas.
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PMID:Thymic epithelial antigen, acquired during ontogeny and defined by the anti-p19 monoclonal antibody, is lost in thymomas. 643 6

Conventional antisera to L-1210 leukemia were being prepared in our laboratory for nearly a decade and consistently the only specificity detectable was anti Mammary Leukemia antigen (ML). Serological analysis of five monoclonal antibodies obtained following the same immunization schedule showed more diverse pattern of reactivity. Two antigens detected belong to oncofetal category. The third one is differentiation antigen Ly-6 and the nature of two others, expressed on leukemic cells only, remains at present unclear. Thus none of the clones analysed produces antibodies to ML antigen. Our previous analysis of cell surface antigens of L-1210 leukemia with the use of conventional antisera has already been described. This paper presents the results of applying monoclonal antibodies in a comparable studies.
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PMID:Cell surface antigens of L-1210 leukemia recognized by monoclonal antibodies. 653 38

Long-term cloned mouse leukemic T cell lines were established in vitro using interleukin-2 (IL-2) conditioned media. The cell lines were tested for retention of both antigenic expression and tumorigenicity, as well as for growth characteristics. Several important findings resulted from these studies. A reliable method was developed for consistent success in the culturing and cloning of leukemic T cell lines. Cultured cells from IL-2-dependent lines were found to retain their original histocompatibility and differentiation antigen characteristics for up to 2 yr. Mortality patterns, comparing long-term cloned leukemic T cell lines with fresh AKR leukemia cells, showed that the cloned cells had greater tumorigenicity. An especially interesting finding was that cell lines established both from different mice and from a single organ of an individual mouse were heterogeneous with respect to antigenic makeup, cell growth kinetics, and tumorigenicity. Finally, because of their dependence on IL-2, the cloned tumor cell lines provided excellent index cells to quantify IL-2 activity.
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PMID:Growth of AKR T cell leukemia lymphoblasts in medium containing interleukin 2 (IL-2). 660 96

A murine monoclonal antibody directed against a normal T-cell differentiation antigen was given to a patient with adult T-cell leukemia. Immunofluorescence staining showed increased amounts of this antigen on the patient's leukemia cells. Using a competition radioimmunoassay, free antigen was not detectable in the serum prior to therapy. Two courses of in vivo therapy were given using a 1-mg dose. Each produced a prompt and dramatic fall in WBC with return to pretreatment levels over the ensuing 24 hr, a pattern similar to that seen with leukopheresis. After the first dose of antibody, circulating free antigen became detectable in the serum and a transient decline in creatinine clearance was noted. A 5-mg dose of antibody given at that time was ineffective, presumably because it was blocked by free antigen. Antigenic modulation by leukemia cells was found transiently following each course of antibody. A weak and clinically insignificant host antimouse antibody response was found 5 days after the first treatment. The patient tolerated antibody therapy without difficulty. Monoclonal antibodies offer promise as an immunotherapeutic approach to cancer but problems encountered here must be addressed.
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PMID:In vivo effects of murine hybridoma monoclonal antibody in a patient with T-cell leukemia. 678 95

A new lymphocyte differentiation antigen shared by all normal T cells and some malignant B cells was defined by a monoclonal antibody designated 12.1. This antibody reacted with all peripheral blood T cells but not with normal B cells and B cell lines. Analysis with a fluorescence activated cell sorter showed that the expression of 12.1 antigen changes during T cell maturation. Most thymocytes, blasts of acute T cell leukemia, and cells from established leukemic T cell lines bear a small amount of 12.1 antigen. In contrast the majority of peripheral blood T cells, activated T cells, and leukemic T cells of the Sezary syndrome bear a large amount of 12.1 antigen. Unexpectedly, antibody 12.1 reacted with leukemic cells from most patients with B-type chronic lymphocytic leukemia (CLL) and some patients with lymphosarcoma cell leukemia (LSCL). Among these leukemias, expression of the 12.1 antigen was not correlated with the stage of B cell maturation, with the amount of surface immunoglobulin on the cells, or with the presence or absence of monoclonal gammapathy. In a comparative serologic analysis the antigen defined by antibody 12.1 was distinct from the p67 T cell antigen (defined by monoclonal antibody 10.2) that is also known to be expressed by B-type CLL cells.
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PMID:A novel human T cell antigen preferentially expressed on mature T cells and shared by both well and poorly differentiated B cell leukemias and lymphomas. 679 Jun 25

The detection of surface-linked antigenic determinants by heteroantisera has greatly contributed to a better understanding of the heterogeneity of benign and malignant hematopoietic cells. The difficulties encountered in rendering these heteroantisera specific for a unique cell surface component have been a major drawback to a more rapid development of immunologic cell typing. With the introduction of hybridoma technology, it became possible to obtain monoclonal antibodies and markedly improve immunologic cell typing. We have, therefore, used this new technology for the production of monoclonal antibodies against human leukocyte surface antigens. This paper describes four cell type-specific monoclonal antibodies, which turned out to be very useful reagents in leukemia diagnosis. One of these antibodies, VIM-D5, is directed against a myeloid cell surface antigen. VIL-A1 is specific for the common acute leukemia associated antigen. VIB-C5 recognizes B-cell differentiation antigen and VIE-G4 is specific for glycophorin A, and thus detects erythroid precursor cells.
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PMID:Surface antigens defined by monoclonal antibodies as tumor markers in human leukemia. 688 86


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