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

In a follow-up of blood recipients, antibodies against adult T-cell leukemia antigen (anti-ATLA) were found in those who had received blood preparations containing cells. Detection of lymphocytes carrying viral antigen of ATLV (human T-cell leukemia virus type I (HTLV-I) ) in seroconverted recipients and the appearance of the viral antigen in cord blood lymphocytes co-cultured with a T-cell clone of a seroconverted recipient strongly suggested that the virus was transmitted through blood transfusion. Screening of blood donors by testing their antibodies against the virus is necessary to prevent future transmission through transfusion, and should be done even if such transmission does not result in the development of adult T-cell leukemia.
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PMID:Transmission of ATLV (HTLV-I) through blood transfusion. 615 57

We have generated and characterized a hybridoma monoclonal antibody, termed SN1, that defines a unique human T-cell leukemia antigen. This antibody was generated by using a human leukemia antigen preparation isolated from cell membranes of MOLT-4, a leukemia T-cell line derived from a patient with T-cell-type acute lymphoblastic leukemia (T-ALL). SN1 was characterized by a sensitive microscale radioimmunoassay using a variety of cultured and uncultured human cells. In selected cases, the cell specimens were further tested by immunoperoxidase staining and an immunofluorescence staining test. The results of the radioimmunoassay were in agreement with those of the two other tests. Among the various cultured malignant and nonmalignant cell lines, SN1 reacted only with leukemia T-cell lines derived from patients with T-ALL; it reacted with all six T-ALL cell lines tested-i.e., JM, CCRF-CEM, CCRF-H-SB2, RPMI 8402, PEER, and MOLT-4. In the case of uncultured cell specimens derived from cancer patients, SN1 reacted with four of four cases of T-ALL but did not react with specimens derived from 41 patients with other types of cancer. SN1 did not react with any normal human cell specimens tested, both cultured and uncultured. These specimens include normal lymphoblastoid cell lines, thymocytes, bone marrow cells, spleen cells, lymph node cells, peripheral blood mononuclear cells, lymphocytes containing B and T cells, purified T cells, monocytes, granulocytes, erythrocytes, and platelets. Furthermore, SN1 did not react with phytohemagglutinin-activated T cells nor with concanavalin A-activated T cells. The results show that monoclonal antibody SN1 defines a type of human leukemia antigen that is expressed on the cell surface of T-cell-type ALL cells. The results further show the usefulness of SN1 in the diagnosis of cancer patients and suggest its therapeutic potential. We designate this antigen TALLA, a T-cell ALL antigen.
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PMID:Monoclonal antibody that defines a unique human T-cell leukemia antigen. 660 Aug 41

We have investigated the anti-leukemia effect that is exerted by the murine anti-CD7 antibody HB2 in a severe combined immunodeficient (SCID) mouse model of human T-cell acute lymphoblastic leukemia (T-ALL) and determined the contribution that this antibody effect makes to the therapeutic potency of a saporin immunotoxin (IT) constructed with the same antibody. The anti-leukemia effect is not exerted through complement-mediated lysis or through direct growth-inhibitory signaling after binding of antibody to the CD7 molecule on the T-ALL cell surface but rather through antibody-dependent cellular cytotoxicity (ADCC). Thus, the in vivo depletion of SCID mice of their natural killer cells almost completely abolishes the therapeutic effect of native HB2 anti-CD7 antibody and moreover significantly reduces the in vivo therapeutic performance of the anti-CD7 HB2-SAPORIN IT. Furthermore, an IT constructed with the F(ab')2 fragment of the same anti-CD7 antibody (HB2-F(ab')2-SAPORIN), which is incapable of recruiting natural killer cells, performed significantly less well therapeutically than HB2-SAPORIN IT. There was also a significant improvement in the therapeutic performance of the HB2-F(ab')2-SAPORIN IT in SCID-HSB-2 mice when used in combination with intact HB2 antibody, presumably through restoration of an ADCC attack on the target HSB-2 cell. These combined data indicate that ADCC in the SCID mouse does contribute additively together with toxin to the in vivo therapeutic potency of the HB2-SAPORIN IT directed against this human T-ALL cell line and that this has potentially important implications for the utility of this and other related classes of immunotherapeutic in human therapy.
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PMID:Host-mediated antibody-dependent cellular cytotoxicity contributes to the in vivo therapeutic efficacy of an anti-CD7-saporin immunotoxin in a severe combined immunodeficient mouse model of human T-cell acute lymphoblastic leukemia. 986 37

CD7 is a single-domain Ig superfamily molecule expressed on human T and NK cells, as well as on cells in the early stages of T, B, and myeloid cell differentiation. CD7 is highly expressed on malignant immature T cells and is generally absent on malignant mature T cells, such as CD4+ Sezary leukemia and HTLV-1+ adult T-cell leukemia cells. Because of lack of identification of a natural ligand and lack of a monoclonal antibody against murine CD7, the in vivo functions of CD7 have until recently remained obscure. Recent studies in CD7-deficient mice have provided new insights into CD7 function, and demonstrated key roles for CD7 in regulating peripheral T and NK cell cytokine production and sensitivity to LPS-induced shock syndromes. This article reviews recent work on the expression, structure, and function of CD7, and discusses roles the CD7 molecule might play in T and NK cell development and function.
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PMID:Structure and function of the CD7 molecule. 1053 Apr 32

Early T-cell precursor (ETP) leukemia represents a new subtype of T-lymphoblastic leukemia/lymphoma with unique immunophenotypes expressing T-cell and one or more of the myeloid/stem cell markers. Here, we report a young patient who had primary mediastinal mass and pleural effusion without bone marrow involvement. A CT-guided mediastinal biopsy and flow cytometry analysis of the pleural effusion revealed the blast cells to have complicated immunophenotypes: strongly expressed T-cell antigen CD7, myeloid-lineage antigens CD33 and CD13 and stem cell markers cTdT, CD34, and HLA-DR; dimly expressed myeloid-lineage specific antigen cMPO and B-cell antigen cCD79a; but did not express T-cell specific antigen cytoplasmic CD3 and B-cell specific antigen CD19. Clonal T-cell receptor rearrangement eventually determined the cell of origin from ETPs, not myeloblasts. The patient showed primary resistance to lymphoid and myeloid-directed induction therapy. Finally, low-dose decitabine combined with modified-CAG regimen induced a complete remission and allogeneic stem cell transplantation was performed as consolidation. The case indicates a primary mediastinal neoplasm from ETP with distinctive immunophenotype from leukemia type. Low-dose decitabine and modified-CAG regimen in combination with allogeneic stem cell transplantation may improve the outcome of patient.
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PMID:Decitabine-containing G-CSF priming regimen overcomes resistance of primary mediastinal neoplasm from early T-cell precursors to conventional chemotherapy: a case report. 3150 24


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