PubMed Health⌕ Search

Biomedical subjects

M Fagioli

Publications and source records attributed to M Fagioli.

18 recordsLinked to original sources
PubMed1992

Identification of DNA rearrangements at the retinoic acid receptor-alpha (RAR-alpha) locus in all patients with acute promyelocytic leukemia (APL) and mapping of APL breakpoints within the RAR-alpha second intron. Italian Cooperative Study Group "GIMEMA".

Seventy patients with acute promyelocytic leukemia (APL) were characterized at the DNA level using genomic retinoic acid receptor-alpha (RAR-alpha) probes on Southern blot experiments. Sixty-two cases were defined as M3 according to the French-American-British (FAB) criteria, and eight had a diagnosis of microgranular or variant (M3v) APL. The use of two restriction enzymes and three probes exploring the second intron of the RAR-alpha gene allowed us to detect specific abnormal DNA fragments in every case, with clustering of rearrangements within the 20-kb intronic region between RAR-alpha exons II and III. A more detailed mapping of APL breakpoints was performed in 52 cases in which three EcoRI subregions of the RAR-alpha second intron were analyzed with corresponding probes. Comparison of clinical and hematological features in the three subgroups of patients with distinct RAR-alpha breakpoints did not show significant differences regarding age, peripheral blood (PB) counts, presence of coagulopathy, or FAB classification (M3 v M3v). Interestingly, a significant difference was observed in the M/F ratio of the three subgroups, with a higher incidence of rearrangements at the 5' end of the RAR-alpha second intron in female patients, and more frequent 3' breakpoints in males. The results of this study indicate that a unique genomic alteration consistently occurs on the 17q- derivative of the APL specific t(15;17) aberration. Moreover, the clinical relevance of RAR-alpha gene analysis both at diagnosis and in follow-up studies is further emphasized.

Adolescent↗
PubMed1992

Expression pattern of the RAR alpha-PML fusion gene in acute promyelocytic leukemia.

Two chimeric genes, PML-RAR alpha and RAR alpha-PML, are formed as a consequence of the acute promyelocytic leukemia (APL)-specific reciprocal translocation of chromosomes 15 and 17 [t(15;17)]. PML-RAR alpha is expressed as a fusion protein. We investigated the organization and expression pattern of the RAR alpha-PML gene in a series of APL patients representative of the molecular heterogeneity of the t(15;17) and found (i) two types of RAR alpha-PML mRNA junctions (RAR alpha exon 2/PML exon 4 or RAR alpha exon 2/PML exon 7) that maintain the RAR alpha and PML longest open reading frames aligned and are the result of chromosome 15 breaking at two different sites; and (ii) 10 different RAR alpha-PML fusion transcripts that differ for the assembly of their PML coding exons. A RAR alpha-PML transcript was present in most, but not all, APL patients.

Base Sequence↗
PubMed1992

Genomic variability and alternative splicing generate multiple PML/RAR alpha transcripts that encode aberrant PML proteins and PML/RAR alpha isoforms in acute promyelocytic leukaemia.

The acute promyelocytic leukaemia (APL) 15;17 translocation generates a PML/RAR alpha chimeric gene which is transcribed as a fusion PML/RAR alpha mRNA. Molecular studies on a large series of APLs revealed great heterogeneity of the PML/RAR alpha transcripts due to: (i) variable breaking of chromosome 15 within three PML breakpoint cluster regions (bcr1, bcr2 and bcr3), (ii) alternative splicings of the PML portion and (iii) alternative usage of two RAR alpha polyadenylation sites. Nucleotide sequence analysis predicted two types of proteins: multiple PML/RAR alpha and aberrant PML. The PML/RAR alpha proteins varied among bcr1, 2 and 3 APL cases and within single cases. The fusion proteins contained variable portions of the PML N terminus joined to the B-F RAR alpha domains; the only PML region retained was the putative DNA binding domain. The aberrant PML proteins lacked the C terminus, which had been replaced by from two to ten amino acid residues from the RAR alpha sequence. Multiple PML/RAR alpha isoforms and aberrant PML proteins were found to coexist in all APLs. These findings indicate that two potential oncogenic proteins are generated by the t(15;17) and suggest that the PML activation pathway is altered in APLs.

Amino Acid Sequence↗
PubMed1992

Alternative splicing of PML transcripts predicts coexpression of several carboxy-terminally different protein isoforms.

The acute promyelocytic leukaemia (APL)-specific chromosome 15;17 translocation leads to the fusion of a newly identified putative transcription factor, PML, and the retinoic acid receptor alpha. We have characterized the structure of the PML genomic locus and preliminarily characterized its expression pattern. The PML locus spans a minimum of 35 kb and is subdivided into nine exons. The putative PML DNA binding site is encoded by exons 2 and 3. We isolated a large number of alternatively spliced PML transcripts that encode numerous PML isoforms. Two groups of isoforms were identified that differed either in their C-terminal region or in the length of their central region, but retained the putative DNA-binding and dimerization domains. RNAase protection experiments revealed that the different PML isoforms are equally expressed in established cell lines of different histological origin.

Amino Acid Sequence↗
PubMed1991

Molecular heterogeneity of the 1.0-kb T beta transcript in natural killer and gamma/delta lymphocytes.

The T cell receptor (TcR) beta chain is encoded by a 1.3-kb mRNA which contains variable (V), diversity (D), joining (J) and constant (C) regions. A shorter 1.0-kb transcript with C but no V sequences is found in thymocytes, alpha/beta and gamma/delta T lymphocytes and natural killer cells. The origin, clonal variability and function of this transcript is unknown. We isolated cDNA clones representative of the 1.0-kb mRNA from cDNA libraries of either polyclonal or clonal natural killer and gamma/delta lymphocytes. Ten different types of cDNA clones belonging to three separate groups were identified: (a) "J-C clones" consisting of one of five J beta regions and the corresponding C beta 1 or C beta 2 regions; (b) "D-J-C clones" composed of D beta 1/or D beta 2/J beta rearranged sequences and C beta 1 or C beta 2 sequences; (c) "5'C clones" made up of C beta 1 or C beta 2 regions preceded by the corresponding genomic 5' flanking region. The presence of recombination signal sequences in J-C and D-J-C clones suggests that the first derive from mRNA transcribed from promoters located in the 5' J region and the second from mRNA transcribed from promoters situated in the 5' D region. Nucleotide sequence analysis demonstrated that only three of the ten types of clones isolated had the potential to code a short cytoplasmic T beta protein with a variable D-J beta N terminus. These findings have implications for the mechanisms of T beta germ-line transcription and the function of the T beta transcripts.

Amino Acid Sequence↗
PubMed1991

Expression of the intestinal T-lymphocyte associated molecule HML-1: analysis of 75 non-Hodgkin's lymphomas and description of the first HML-1 positive T-lymphoblastic tumour.

The expression of the gut intra-epithelial T-cell associated molecule HML-1, a trimeric protein of 150, 125, 105 kD, was studied in 75 T-cell lymphomas of different subtypes: 20 T-lymphoblastic lymphomas/leukaemias; 50 nodal peripheral T-cell lymphomas; and five intestinal T-cell lymphomas. Our results confirm: (i) the usefulness of the HML-1 monoclonal antibody as an immunohistochemical marker for intestinal T-cell lymphomas: and (ii) the lack of reactivity of HML-1 with nodal peripheral T-cell lymphomas. Moreover, expression of the HML-1 molecule was found for the first time in a case of T-lymphoblastic lymphoma/leukaemia. The patient presented with a mediastinal mass which consisted of HML-1 + neoplastic cells displaying a phenotypic profile consistent with early thymocytes. Genes coding for the alpha, beta, gamma and delta chains of the T-cell receptor were in a germline configuration. The neoplastic cells could have been derived from the small subset of HML-1 + thymocytes detectable in the cortex of normal human thymus.

Adolescent↗
PubMed1990

The C gamma 1-encoded disulphide-linked and the C gamma 2-encoded nondisulphide-linked forms of the gamma/delta heterodimer use different gamma and delta variable regions.

We identified two types of gamma/delta T-cell clones: (1) BB3+ clones, which express the disulphide-linked form of the gamma/delta heterodimer (type 1 receptor) and carry rearrangements of the C gamma 1 gene; and (2) delta TCS1+ clones, which express the nondisulphide-linked form of the gamma/delta heterodimer (type 2 receptor) and carry rearrangements of the C gamma 2 gene. To determine the joining (J) and variable (V) region usage of the two receptor types, T gamma and T delta gene rearrangements and expression were analyzed in each gamma/delta T-cell clone. The results showed that the J and V regions used by the two receptor types are distinct: clones that express the type 1 receptor carry potentially functional rearrangements in J gamma P-V gamma 9 for gamma and in J delta 1-V delta 2 for delta; and clones that express the type 2 receptor had potentially functional rearrangements in J gamma 2-V gamma 2/V gamma 4 for gamma and in J delta 1-V delta 1 for delta. Therefore, two clearly different gamma/delta receptors (V gamma 9-J gamma P-C gamma 1/V delta 2-J delta 1-C delta and V gamma 2/V gamma 4-J gamma 2-C gamma 2/V delta 1-J delta 1-C delta) predominate in peripheral blood.

Adult↗
PubMed1990

Peripheral T-cell lymphoma associated with hemophagocytic syndrome.

Nine patients with an acute disease characterized by high fever, loss of weight, prominent hepatosplenomegaly, slight or no lymphadenopathy, abnormal liver function tests, and profound pancytopenia are reported. In all cases, the disease presented in the absence of any pre-existing disease or immunosuppressive therapy. In seven of the nine patients, survival was very short (mean = 7 weeks). Two patients are still alive: one had a relapse 24 months after the initial diagnosis, while the other is in complete remission. The main pathological feature was the infiltration of the marrow, spleen and liver by neoplastic T cells, accompanied by an exuberant hyperplasia of benign-looking, hemophagocytizing histiocytes. The term "peripheral T-cell lymphoma with hemophagocytic syndrome" is proposed for this condition. Retrospective analysis of stored paraffin material (1949 to 1965) from the Radcliffe Infirmary files suggests that at least some of the cases designated as "histiocytic medullary reticulosis" by Scott and Robb-Smith were examples of the syndrome herein described.

Autopsy↗
PubMed1990

Natural killer cells carry the germ-line configuration of the T cell receptor delta chain gene and heterogeneously express six distinct delta transcripts.

Investigations on T cell receptor delta chain (TcR delta) gene expression in freshly isolated normal large granular lymphocytes, natural killer (NK) cell clones and NK bulk cultures revealed six T delta transcripts (3.5, 3.1, 2.2, 2.0, 1.5 and 1.3 kb) which varied in number and relative abundance in the different samples. None of the six known T delta variable regions was expressed and the T delta locus was retained in its germ-line configuration. The origin and significance of these NK-associated T delta transcripts are discussed.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1990

Interleukin-2-dependent long-term cultures of low-density lymphocytes allow the proliferation of lymphokine-activated killer cells with natural killer, Ti gamma/delta or TNK phenotype.

We have developed a culture system for "long-term" growth of human lymphokine-activated killer (LAK) cells exhibiting an elevated, wide-spectrum antitumor cytotoxicity. The system allows the exponential growth of monocyte-depleted low-density lymphocytes in the presence of human serum and recombinant human interleukin-2 (10(3) U/ml), alone or in combination with interleukin-1 alpha or beta (both at 10 U/ml). Eighteen cultures were established from 18 normal adult donors. The membrane phenotypes of the final LAK cell population, assessed by a panel of monoclonal antibodies (mAb), consist of three main types: (a) NKH-1+, Ti alpha/beta-, Ti gamma/delta-, and CD3- lymphocytes; (b) NKH-1+, Ti alpha/beta-, Ti gamma/delta+, and CD3+ lymphocytes and (c) NKH-1+, Ti alpha/beta+, Ti gamma/delta- and CD3+ lymphocytes. Northern blot analysis showed that all these cell populations express relatively high levels of perforin RNA, particularly cells exhibiting the first phenotype. This culture system may provide a tool for cellular and molecular studies on the mechanisms of antitumor cytotoxicity, as well as the basis for new adoptive immunotherapy protocols in advanced center.

Antigens, CD↗
PubMed1990

Molecular studies on LAK cells.

We have developed a culture system for long-term growth of human LAK cells exhibiting an elevated, wide-spectrum anti-tumor cytotoxicity. The phenotypic and molecular properties of the final LAK cell populations indicated that they consist of three main types: a) NK-like lymphocytes (type I): NKH-1+, Ti alpha/beta-, Ti gamma/delta-, CD3-lymphocytes carrying the germline configuration of all TCR genes and expressing variable amount of the 1.0 beta mRNA and variably sized T delta transcripts; b) gamma/delta-like T lymphocytes (type II) NKH-1+, Ti alpha/beta-, Ti gamma/delta+, CD3+ lymphocytes carrying polyclonal rearrangements of the gamma and delta genes and expressing high levels of mature gamma and delta transcripts; c) alpha/beta-like T lymphocytes (type III): NKH-1+, Ti alpha/beta+, Ti gamma/delta-, CD3+ lymphocytes carrying rearrangements of all TCR genes and expressing high levels of mature alpha and beta transcripts. We took advantage of the high number of available LAK cells to clarify: 1) the origin of the NK-LAK delta transcripts. delta gene expression in LGL, NK clones and type I LAK cultures revealed six delta transcripts (3.5, 3.1, 2.2, 2.0, 1.5 and 1.3 kb), which varied in number and relative abundance in the different samples. None of the six known V delta was expressed and the delta locus was retained in its germline configuration suggesting that the delta expression is due to a partially rearranged or germline transcripts; 2) the origin of the NK-LAK truncated T beta transcript. We isolated two different clone types from a type I LAK cell cDNA library: a) J-C clones consisting of one of three J beta regions and the corresponding C beta 1 or C beta 2 regions; b) X-J-C and C-X clones, containing as yet unidentified (X) sequences. The presence of RSSs in J-C clones suggests that they derive from mRNAs transcribed from a promoter in the 5'J. Nucleotide analysis demonstrated that only one of the isolated clones had the potential to code a short T beta protein.

Amino Acid Sequence↗
PubMed1989

T-lymphoblastic lymphomas expressing the non-disulfide-linked form of the T-cell receptor gamma/delta: characterization with monoclonal antibodies and genotypic analysis.

Three cases of T-lymphoblastic lymphomas (T-LL) expressing the T cell antigen receptor gamma delta (TCR gamma delta) are reported. All of them were CD3+/beta F1-/TCR delta 1+. Moreover, neoplastic cells reacted with the delta TCS1 monoclonal antibody (MoAb) which binds to the non-disulfide-linked form of the TCR gamma delta, but not with the BB3 MoAb which recognizes the disulfide-linked form of the TCR gamma delta. All cases showed a stage II cortical phenotype, eg, TdT+/CD1+/CD3+/CD5+/CD7+; two of them coexpressed CD4/CD8, while the other was CD4+/CD8-. Two cases were positive for CALLA and CD25. Immunogenotypic analysis showed evidence of T beta and C gamma 2 gene rearrangements in all three cases and immunoglobulin (Ig) gene rearrangements in two cases. Two patients presented with an anterior mediastinal mass and the third with a solitary inguinal lymphadenopathy. We suggest that these cases of TCR gamma delta+ T-LL may be derived from the small population (approximately 0.5%) of CD3+ cortical thymocytes which, in the normal human thymus, express the delta TCS1-reactive, non-disulfide-linked form of the TCR gamma delta.

Antibodies, Monoclonal↗
PubMed1989

Distribution of T cells bearing different forms of the T cell receptor gamma/delta in normal and pathological human tissues.

Frozen sections from normal and pathologic human tissues were immunostained by the APAAP technique with three mAb directed against different epitopes of the TCR gamma delta; TCR delta 1 which binds to all cells bearing the TCR gamma delta; BB3 and delta TCS1 which, by immunoprecipitation studies, appear to react respectively with the disulfide-linked and nondisulfide-linked form of the TCR gamma delta. In normal thymus, TCR delta 1+ cells accounted for approximately 2% of the CD3+ thymocytes and were about three times more numerous in the medulla than in the cortex. TCR delta 1+ cells were mostly constituted by the delta TCS1 reactive subset (average ratio delta TCS1/BB3: 3.7). In the tonsil, the TCR delta 1+ cells (about 3% of CD3+ elements) were mainly located in the interfollicular area, where they frequently tended to arrange around high endothelium venules. In most samples, TCR delta 1+ cells were distributed beneath to the tonsil epithelium. Unlike thymus, the majority of TCR delta 1+ cells were usually constituted by the BB3-reactive subset (average BB3/delta TCS1 ratio: 2.0). A similar predominance of BB3+ over delta TCS1+ cells was also observed in normal peripheral blood. The spleen was the organ with the highest concentration of TCR delta 1+ cells that, like in the thymus, were mostly represented by delta TCS1+ elements. Noteworthy, the TCR delta 1+ cells were preferentially located in the splenic sinusoids while TCR alpha beta-bearing lymphocytes mostly occupied the periarteriolar sheaths of penicilliary arteries. The majority of neoplastic T cell proliferations studied lacked to express the TCR gamma delta. Two cases of beta F1-(TCR alpha beta-) T lymphoblastic lymphoma, however, were TCR gamma delta+ (delta TCS1+/BB3-). Both of them showed a stage II cortical phenotype, e.g., CD1+/CD3+/CD4+/CD8+/TCR delta 1+. Among inflammatory conditions, an increase of BB3+ cells was observed in close association with necrotic areas in cases of Kikuchi's and tuberculous lymphadenitis. The significance of this finding is under study.

Antibodies, Monoclonal↗
PubMed1989

Evolutionary conservation in various mammalian species of the human proliferation-associated epitope recognized by the Ki-67 monoclonal antibody.

The human proliferation-associated epitope recognized by the Ki-67 monoclonal antibody (MAb) was detected in proliferating normal and neoplastic cells of many mammalian species (lamb, calf, dog, rabbit, rat) besides human. In contrast, Ki-67 stained proliferating cells from other species weakly (mouse) or not at all (swine, cat, chicken, pigeon). The immunostaining pattern of Ki-67 in animal tissues was identical to that previously described in human: Ki-67 reacted only with cells known to proliferate (e.g., germinal center cells, cortical thymocytes) but not with resting cells (e.g., hepatocytes, brain cells, renal cells); this MAb produced a characteristic nuclear staining pattern (e.g., stronger labeling of nucleoli than of the rest of the nuclei and staining of chromosomes in mitotic figures); and Ki-67 crossreacted with the squamous epithelium in both animal and human tissues. In vitro studies showed that when quiescent (Ki-67-negative) NIH 3T3 fibroblasts or bovine peripheral blood lymphocytes were induced to proliferate, the appearance of Ki-67-positive cells paralleled the induction of cell proliferation caused by addition of fetal calf serum or PHA, respectively, to the cultures, and in both human and rat proliferating cells the Ki-67 expression closely paralleled the incorporation of [3H]-thymidine. These findings indicate that the epitope recognized by the Ki-67 MAb in human and animal species is the same. The widespread evolutionary conservation of the human proliferation-associated epitope recognized by the Ki-67 MAb suggests that it and/or its carrier molecule may play an important role in regulation of cell proliferation.

Animals↗
PubMed1988

Immunocytochemical evaluation of the percentage of proliferating cells in pathological bone marrow and peripheral blood samples with the Ki-67 and anti-bromo-deoxyuridine monoclonal antibodies.

The monoclonal antibody Ki-67, directed against a nuclear antigen expressed by dividing cells in all the phases of cell cycle except G0 and early G1, was used in combination with an anti-BrdU monoclonal antibody, reacting selectively with cells in S-phase, for assessing the percentage of proliferating cells in bone marrow and peripheral blood samples from patients with lymphoma, leukaemia and multiple myeloma. Immunocytochemical labelling of proliferating cells was performed on marrow frozen sections and/or cytospins using an immunoalkaline phosphatase (APAAP) technique that made it possible to obtain proliferative index measurements in a few hours in contrast to the 3-7 d needed with tritiated thymidine. In the 54 marrow lymphoma cases studied a highly significant correlation was observed between the proportion of Ki-67 (+) cells and the separation into low- and high-grade malignant lymphomas according to the Kiel classification. In patients with multiple myeloma at the first diagnosis, the percentage of Ki-67 (+) cells was low (6-10%). In contrast, a high percentage of Ki-67 (+) cells (40-50%) was observed in a young adult with multiple myeloma, in a patient who first presented at the clinical observation with an extradural mass and in three patients who developed extramedullary masses several years after the initial diagnosis of myeloma. In acute lymphoblastic leukaemias of common type the mean value of Ki-67 labelling was 31.3%. Because of their simplicity and rapidity, immunocytochemical techniques may be expected to replace autoradiography and flow cytometry for the detection of proliferating cells in haematological samples.

Antibodies, Monoclonal↗
PubMed1988

Large cell lymphoma of bone. A report of three cases of B-cell origin.

Clinicopathological and immunohistological features of three cases of large cell lymphoma of bone are reported. On histological grounds, all the cases were diagnosed as histiocytic lymphomas (Rappaport) or primary centroblastic lymphomas, polymorphic subtype (Kiel). On immunophenotyping, malignant cells strongly reacted with the anti-leucocyte antibodies PD7/26 and ROS-220C, thereby indicating their lymphomatous nature, and expressed the B-cell antigens CD19 and CD22. Further studies are warranted to determine whether the B-cell phenotype observed in our cases is typical of the majority of primary large cell lymphomas of bone. Immunohistological analysis with monoclonal antibodies is expected to be of great value not only in defining the immunological phenotype of this rare pathological entity, but also in differentiating it from other neoplasms that involve the skeleton, either primarily or secondarily.

Adult↗
PubMed1987

Expression of lymphoid-associated antigens on Hodgkin's and Reed-Sternberg cells of Hodgkin's disease. An immunocytochemical study on lymph node cytospins using monoclonal antibodies.

The aim of this study was to elucidate the origin of Hodgkin's and Reed-Sternberg cells. Lymph node cytospins and frozen sections from 20 cases of Hodgkin's disease of different histological subtypes were immunostained by the immuno-alkaline phosphatase technique using a panel of monoclonal antibodies. As expected, the Hodgkin's and Reed-Sternberg cells of all cases were positive for the CD30 (Ki-1), CD15 (hapten X) and CD25 (Tac) antigens. In eight cases, a variable percentage of typical Hodgkin's and Reed-Sternberg cells showed a clear-cut cytoplasmic and/or surface positivity for the T-cell-associated antigens CD3, CD5, CD6 and CD4 (seven cases) or CD8 (one case), but consistently lacked B-cell and macrophage-associated markers. The best visualization of T-cell antigens was obtained in cytocentrifuge preparations and in areas of lymph node frozen sections that had been infiltrated by clusters of Hodgkin's and Reed-Sternberg cells. In two cases of Hodgkin's disease (nodular sclerosis, mixed cellularity) the neoplastic cells weakly expressed the B-cell antigens CD19 and CD22, but not T-cell or macrophage-associated markers. In 10 cases, Hodgkin's and Reed-Sternberg cells were negative for all the lymphoid- and macrophage-associated antigens. These results suggest a lymphoid (either T or B) rather than histiocytic origin for the Hodgkin's and Reed-Sternberg cells in a number of Hodgkin's disease cases.

Antibodies, Monoclonal↗