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)

We have generated mice that carry a germline mutation in which a large portion of the RAG-2 coding region is deleted. Homozygous mutants are viable but fail to produce mature B or T lymphocytes. Very immature lymphoid cells were present in primary lymphoid organs of mutant animals as defined by surface marker analyses and Abelson murine leukemia virus (A-MuLV) transformation assays. However, these cells did not rearrange their immunoglobulin or T cell receptor loci. Lack of V(D)J recombination activity in mutant pre-B cell lines could be restored by introduction of a functional RAG-2 expression vector. Therefore, loss of RAG-2 function in vivo results in total inability to initiate V(D)J rearrangement, leading to a novel severe combined immune deficient (SCID) phenotype. Because the SCID phenotype was the only obvious abnormality detected in RAG-2 mutant mice, RAG-2 function and V(D)J recombinase activity, per se, are not required for development of cells other than lymphocytes.
 ...
PMID:RAG-2-deficient mice lack mature lymphocytes owing to inability to initiate V(D)J rearrangement. 154 87

Members of the Ets family of proto-oncogenes encode sequence-specific transcription factors that bind to a purine-rich motif centered around a conserved GGA trinucleotide. Ets binding sites have been identified in the transcriptional regulatory regions of multiple T cell genes including the T cell receptor alpha and beta (TCR-alpha and -beta) enhancers and the IL-2 enhancer, as well as in the enhancers of several T cell-trophic viruses including Maloney sarcoma virus, human leukemia virus type 1, and human immunodeficiency virus-2. T cells express multiple members of the Ets gene family including Ets-1, Ets-2, GABP alpha, Elf-1, and Fli-1. The different patterns of expression and protein-protein interactions of these different Ets family members undoubtedly contribute to their ability to specifically regulate distinct sets of T cell genes. However, previous studies have suggested that different Ets family members might also display distinct DNA binding specificities. In this report, we have examined the DNA binding characteristics of two Ets family members, Ets-1 and Elf-1, that are highly expressed in T cells. The results demonstrate that the minimal DNA binding domain of these proteins consists of adjacent basic and putative alpha-helical regions that are conserved in all of the known Ets family members. Both regions are required for DNA binding activity. In vitro binding studies demonstrated that Ets-1 and Elf-1 display distinct DNA binding specificities, and, thereby interact preferentially with different naturally occurring Ets binding sites. A comparison of known Ets binding sites identified three nucleotides at the 3' end of these sequences that control the differential binding of the Ets-1 and Elf-1 proteins. These results are consistent with a model in which different Ets family members regulate the expression of different T cell genes by binding preferentially to purine-rich sequences that share a GGA core motif, but contain distinct flanking sequences.
 ...
PMID:Evolutionarily conserved Ets family members display distinct DNA binding specificities. 156 4

Rearrangements of the heavy chain immunoglobulin gene and T cell receptor beta gene were investigated in 25 patients suffering from precursor B cell acute leukaemia and six patients suffering from T cell acute leukaemia using biotinylated DNA probes. All precursor B acute leukaemia patients had IgH gene rearrangements and 63% of those studied also had TCR beta gene rearrangements. All T cell acute leukaemia patients had TCR beta gene rearrangements and germline IgH configuration. Dilution experiments indicated that DNA from leukaemic cells representing 1-2% of a tested sample could be detected using this technique which compares favourably to radioactive DNA probes.
 ...
PMID:Non-radioactive detection of immunoglobulin and T cell receptor gene rearrangement in acute lymphoblastic leukaemia. 166 Nov 25

Transplantation of immunocompetent cells present within allogeneic bone marrow has been associated with the elimination of residual host leukemia, both in animal tumor models and in patients receiving marrow transplants for leukemia. This observation has been called the "graft-versus-leukemia effect." We have attempted to study this phenomenon in vitro by characterizing the cytolytic response of T cells from normal donors after in vitro activation with allogeneic leukemic cells. As expected, most T cells that react against an allogeneic patient's leukemic cells recognize their foreign HLA antigens and lyse the patient's nonleukemic remission lymphoid cells. In addition, we have shown that a small fraction of the T cells recognize and lyse foreign leukemic targets without lysis of nonmalignant remission targets from the same leukemic patient. These T cells have been isolated and characterized as CD3+, CD4+ cells expressing the alpha/beta T cell receptor (TCR). Their lysis appears to reflect specific antigen recognition mediated via the CD3-TCR complex and interactions involving the CD4 receptor. Some of these "leukemic specific" T cell lines, which are restricted by HLA class II molecules, can also lyse occasional nonleukemic cells from certain unrelated donors. This recognition appears to involve crossreactive determinants shared by the leukemic cells and the unrelated allogeneic nonleukemic cells. These specific interactions may represent an in vitro model of the graft-versus-leukemia effect.
 ...
PMID:Specific recognition of human leukemic cells by allogeneic T cells: II. Evidence for HLA-D restricted determinants on leukemic cells that are crossreactive with determinants present on unrelated nonleukemic cells. 169 92

We report here a patient with acute monoblastic leukemia whose leukemia cells had CD4 (T4) and CD56 (NKH-1) antigens, in addition to CD36 (OKM5) antigen. The leukemia cells did not have NK or ADCC activities. They showed no rearrangements of immunoglobulin heavy (IgH) chain and T cell receptor (TCR)-beta chain genes, indicating that the leukemia cells were nonlymphoid. The presence of this case suggests that leukemia cells could be originated from monocytes with NK-associated antigen without IgH or TCR rearrangements.
 ...
PMID:CD4+ and CD56+ acute monoblastic leukemia. 169 29

Within normal hemopoiesis, the intranuclear DNA polymerase TdT seems to be exclusively expressed by T and B lymphoid precursor cells. Double staining experiments showed that TdT can also be expressed in blast cells of certain acute myeloid leukemias. Recent reports described a very strong association between TdT expression and rearrangements of IgH and TcR genes in such AML specimens, suggesting a predominant lymphoid commitment of these TdT positive AML blasts. When submitting 24 serologically and morphologically well-characterized TdT positive AML specimens for additional genotypic analysis to determine the IgH and TcR gene configuration, we observed that only four had clonally rearranged IgH and/or TcR genes, whereas 20 had germ line configuration. This frequency is clearly lower than previously reported and not necessarily different from rearrangement frequencies reported for TdT negative AML (4-40%). It would seem to us, therefore, that the expression of TdT in otherwise well-defined AML blasts is not necessarily associated with a higher frequency of immunoglobulin and/or T cell receptor gene rearrangement.
Leukemia 1990 Apr
PMID:Terminal deoxynucleotidyl transferase and CD7 expression in acute myeloid leukemias are not associated with a high frequency of immunoglobulin and/or T cell receptor gene rearrangement. 169 41

We have previously shown that large granular lymphocyte (LGL)-enriched cell populations have the capacity to spontaneously recognize and kill allogeneic small lymphocytes and bone marrow cells (BMC) in vitro in certain strain combinations of rats. Here, we have studied the alloreactivity of natural killer (NK) cells from PVG nude (RT1c) rats against a panel of major histocompatibility complex (MHC) incompatible hemic cells. Both lymphocytes and BMC from the AO (RT1u), DA (RT1a), BN (RT1n) as well as the MHC-congenic PVG-RT1u (RT1u) rat strains were efficiently killed in vitro, whereas cells from syngeneic PVG rats were spared. The structures recognized on lymphocytes and BMC were probably similar since the two cell populations inhibited each other in cross-competition experiments. A number of features aligned the alloreactive effector cells with NK cells and not T cells. (a) Only about 5% of the effector cells from nude spleens expressed the T cell antigens CD3, CD5 or T cell receptor (TcR) alpha/beta whereas greater than 50% of the cells expressed markers present on NK cells (CD2, CD8, OX52 and the rat NK cell-specific marker NKR-P1 recognized by the monoclonal antibody 3.2.3). (b) The alloreactive cells were granular since pretreatment of nude spleen cells with the lysosomotropic agent L-leucine methyl ester which eliminated LGL, simultaneously abolished the cytolysis of both allogeneic lymphocytes and YAC-1 tumor cells. (c) Nude spleen cells stimulated with human recombinant interleukin 2 for 1 week in vitro generated large granular proliferating cells which were CD3-, CD5-, TcR alpha/beta-, but greater than 95% 3.2.3+. These cells efficiently killed allogeneic hemic cells from the same rat strains as did freshly isolated effector cells. (d) The cytolysis of allogeneic hemic cells could effectively be inhibited with unlabelled NK-sensitive (YAC-1 and K-562), but not NK-resistant (Roser leukemia) tumor cells. Cross-competition studies showed that PVG nude NK cells discriminated between AO, BN and DA BMC, suggesting that different alloantigens were positively recognized by subsets of NK cells. The mode of inheritance of the allodeterminant specifically recognized on AO BMC was investigated in crosses and backcrosses between AO and BN or DA rats. A gene dosage effect was observed in that this determinant was expressed at a slightly reduced level in F1 hybrids.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Allospecific recognition of hemic cells in vitro by natural killer cells from athymic rats: evidence that allodeterminants coded for by single major histocompatibility complex haplotypes are recognized. 171 12

Diagnosis of leukemia and lymphoma has been made by morphological, cytochemical, and immunophenotypical methods. Recently molecular biological approaches have been introduced to clarify the cellular lineage of the tumor cells and to demonstrate the monoclonality. Southern blot analysis using immunoglobulin (Ig) and T cell receptor (TcR) genes revealed the presence of monoclonal components in some cases of angioimmunoblastic lymphadenopathy (AILD), in which demonstration of monoclonality was difficult by conventional methods. In preB-ALL, many cases had rearranged IgH and TcR genes simultaneously. These "dual genotype" cases were found to be of accidental involvement of TcR gene in the process of making effective IgH gene rearrangements by the precise analysis of rearranged IgH gene structures. The rearranged TcR gene which was detected in initial lymphoblastic lymphoma cells, was observed in relapsed blasts after lineage conversion to myeloid leukemia, which indicates the same clonal origin. Diagnosis and detection of minimal residual disease by the polymerase chain reaction (PCR) are now recognized as sensitive methods. PCR using oligonucleotides common to each VH and JH gene detects the rearranged IgH gene sensitively. PCR using primers located on the translocation boundary, such as bcr and abl in CML, is very useful in the diagnosis and pursuit of the disease course. PCR study also can be applied to the detection of alteration of some particular genes such as tumor suppressor genes.
 ...
PMID:[Molecular diagnosis of leukemia and lymphoma]. 176 82

In acute leukemia residual disease is usually monitored by morphology. The precision of this approach can be improved by several methods including the investigation of chromosomal abnormalities by conventional cytogenetics, flow karyotyping, in situ hybridization and polymerase chain reaction (PCR), and the analysis of immunoglobulin and T cell receptor genes by Southern blotting and PCR. Immunologic methods represent a reliable option for studying residual disease in approximately half of the patients with acute leukemia. This strategy is based on the observation that some marker combinations are expressed on leukemic blasts but are absent or rarely present in normal peripheral blood (PB), bone marrow (BM) or cerebrospinal fluid cells. In patients with T cell-acute lymphoblastic leukemia, even one cell simultaneously expressing terminal deoxynucleotidyl transferase and CD3, CD5 or CD1 amongst 10(5) PB or BM cells indicates residual disease. Some cases of B lineage and myeloid acute leukemias also exhibit phenotypes potentially useful for monitoring response to treatment. Such phenotypes are identified by double or triple color staining techniques using fluorescence microscopy or flow cytometry. Independent studies have demonstrated that detection of cells with leukemia-associated phenotypes in BM samples of patients in clinic and morphologic remission heralds the recurrence of leukemia. It is likely that a combination of techniques will be needed to monitor the majority of patients with acute leukemia. Advantages and disadvantages of individual methods should be determined in comparative preclinic investigations. These studies should yield sufficient information to initiate the testing of therapeutic strategies planned according to the data provided by use of modern sensitive techniques.
 ...
PMID:The definition of remission in acute leukemia with immunologic techniques. 179 Apr 23

Various samples from lymphoproliferative diseases in the skin were analyzed by Southern blotting technique with probes from the T cell receptor gene, immunoglobulin genes, and human T cell leukemia virus-I genome. Samples were taken from 10 mycosis fungoides (MF) patients, 1 parapsoriasis en plaque patient, 10 Adult T cell leukemia/lymphoma (ATL) patients, 1 cutaneous T cell lymphoma (CTCL) patient, 4 lymphomatoid papulosis (LP) patients, 4 B cell lymphoma patients, and 2 actinic reticuloid (AR) patients. In MF, the monoclonality of the T cells became detectable first in the skin when plaques develop to tumors then in lymph nodes, and finally in the blood lymphocytes, indicating this disease develops from local (skin) malignancy to systemic malignancy. In parapsoriasis en plaque, no monoclonality was detected in any sample. We could distinguish cutaneous ATL from the carrier state by detecting the T cell monoclonality and HTLV-I integration with these probes. One patient with CTCL showed detectable T cell monoclonality; 1 out of 4 patients with LP did the same. Four samples from patients with B cell lymphoma revealed detectable monoclonal rearrangement of immunoglobulin heavy and light chain genes. In AR, no monoclonality was detected in any sample. From these data, we conclude that DNA analysis is useful in determining the monoclonality, cell origin, and distribution of monoclonal cells from skin samples.
 ...
PMID:Characterization of the lymphoproliferative diseases in the skin by DNA analysis. 180 May 28


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>