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Immunogenotypes and clonal culture analysis in B-precursor acute lymphoblastic leukemia.

Immunogenotypic changes in 32 patients with B-precursor acute lymphoblastic leukemia (ALL), including three patients with t(4;11) and 13 with t(9;22), were determined using immunoglobulin heavy (IgH) chain gene probe and T-cell receptor beta, gamma and delta chain gene probes. Clonogenic assay was performed in 12 of the 32 patients. In this study, four patients had a germline configuration of the IgH chain gene, showing a dissociation between phenotypic and genotypic expression; three patients had Philadelphia-positive (Ph+) ALL. The immunogenotypic manifestation in Ph+ ALL does not depend on whether the leukemia cells had rearrangement within the major breakpoint cluster region (major-BCR) DNA sequence or the leukemia cells had myeloid-associated antigens. Colony assay using various recombinant cytokines demonstrated that the leukemia cells from four of 12 patients formed colonies in response to myelopoietic stimulants; three of the four patients were major-BCR-rearranged Ph+ ALL. Notably, cells from one patient with Ph+ ALL formed colonies on the addition of granulocytic colony-stimulating factor. This indicates not only the biological heterogeneity of ALL cells but also that some of the characteristics of the cells are related to specific chromosome changes.

Adult↗

Enhanced expression of class I major histocompatibility complex gene (Dk) products on immunogenic variants of a spontaneous murine carcinoma.

Both immunogenic and nonimmunogenic variant clones were isolated from a recently obtained spontaneous murine adenocarcinoma after treatment (xenogenization) with either the mutagen ethyl methanesulfonate or the DNA hypomethylating agent, and "gene activator," 5-azacytidine. Clonal analysis of the untreated tumor population confirmed that immunogenic variants arose as a consequence of the xenogenization protocol. At a dose of 10(6) cells per mouse, nonimmunogenic variants, like the parental tumor line, grew progressively in normal syngeneic recipients. In contrast, immunogenic variants were rejected in normal syngeneic mice and grew progressively only in T-cell-deficient nude mice. Serologic analysis of the respective clonal variants revealed that immunogenic variants expressed substantially elevated (fourfold to tenfold) levels of class I H-2Dk antigen relative to parental or nonimmunogenic cell lines. Two variants exhibiting marginal immunogenicity expressed high and low levels of major histocompatibility complex (MHC) antigen, respectively suggesting that elevated MHC expression, although possibly a contributing factor, did not account for the immunogenic phenotype in all cases. Finally, the immunogenic phenotype of two variants decayed with time in culture. Clones in the process of reversion lost their elevated Dk gene expression and became progressively more tumorigenic in normal syngeneic mice. Together, these data are consistent with a hypothesis that elevated MHC expression can contribute to the immunogenic phenotype of originally low MHC-expressing tumors and that the reduced level of MHC observed in certain clinical cancers may have significant implications with regard to immunologic aspects of the tumor-host relationship.

Animals↗

Molecular analysis of clonal stability and longevity in B cell memory.

We used the antiphosphocholine response induced by Proteus morganii and an adoptive transfer protocol to study the contribution of individual clones to B cell memory. Spleen cells from donor mice immunized with P. morganii were injected into irradiated hosts. These recipients were then immunized and their spleen cells fused 12 to 14 wk thereafter. The sequences of hybridoma VH and VL were obtained and DNA rearrangements at both V region loci were studied to ascertain clonal relationships. In all three adoptive transfer experiments, each mouse of a pair receiving cells from the same donor contained hybridomas which were clonally related to each other. In two of these experiments paired recipients possessed cells that had identically mutated V genes. These results lead us to conclude that once a B cell clone(s) dominates a response, progeny of that clone form the memory cell population for many months. Moreover, stability appears to be generated in some memory B cells through inactivation of the hypermutation mechanism.

Amino Acid Sequence↗

Molecular genetic approach to the analysis of clonal proliferation in hematologic disorders.

The clonal composition of each cell population was determined from the characteristic methylation pattern of DNA and the restriction fragment length polymorphism (RFLP) of the hypoxanthine phosphoribosyltransferase (HPRT) and phosphoglycerate kinase (PGK) genes, both located on the X chromosome. About 71% of Japanese females are heterozygous in terms of the RFLP of either HPRT or PGK genes, which was demonstrated by using 5' genomic DNA or cDNA probes for these genes. All 3 cases of chronic myeloproliferative disorders showed monoclonal patterns. AML or ALL cases demonstrated either monoclonal or polyclonal patterns depending upon the percentage of blastic cells. Monoclonal patterns were seen in 3 of 4 cases of myelodysplastic syndromes and both PNH cases.

Cell Division↗

Molecular analysis of clonality in Castleman's disease.

Castleman's disease (CD) is a rare atypical lymphoproliferative disorder that is morphologically and clinically heterogenous and is associated with a risk of developing malignant lymphoma. We report the clonality status of CD tissues in 34 patients, including 14 patients infected by the human immunodeficiency virus (HIV). Four patients presented a localized form and 30 presented a multicentric form. Two cases were associated with B-cell lymphoma, 3 cases with Hodgkin's disease, and 9 cases (8 HIV+) with Kaposi's sarcoma. Histologically, 8 cases were of the hyaline-vascular type and 26 were of the plasma cell or mixed types. The Ig and T-cell receptor (TCR) V(D)J rearrangements were analyzed using polymerase chain reaction and Southern blot. Clonal IgH rearrangements were detected in only 4 cases, ie, 2 associated with B-cell lymphoma, 1 with Hodgkin's disease, and 1 case without malignancy. A TCR gamma rearrangement of restricted junctional size was amplified in 1 HIV+ case. Finally, polyclonal VH-JH and V gamma-J gamma rearrangements were detected in the large majority of the cases, irrespective of pathologic subtypes, clinical forms, and HIV status. The lymphoid component in CD is therefore commonly reactive, and the rare occurrence of detectable monoclonal lymphoid contingents may be caused by secondary molecular events.

Adult↗

Analysis of clonal CD8+ T cell expansions in normal individuals and patients with rheumatoid arthritis.

In the course of studying the circulating TCR repertoire in humans, we noted several individuals with an increase in the percentage of CD8+ T cells expressing a particular V region. In some cases, these CD8 expansions were dramatic, occupying over 40% of the total CD8 repertoire. Using a panel of mAbs to different TCR V regions, we found that over 30% of healthy adults (> 35 years of age) harbor an expansion that alters the peripheral blood CD8 TCR repertoire. A wide range of V regions were expressed by these expansions. Considering that the mAbs used cover only a portion of the V beta repertoire, the data suggest that over 70% of adults are likely to harbor such expansions. Junctional region sequencing showed that the CD8 subset expansions were clonal, and serial studies as long as 4 years showed that they persisted indefinitely. Expansions were not identified in the CD4 population. Discordant expression of one large V beta 6.7+ clone was found in one identical twin set, suggesting the possibility that an environmental exposure is involved in their generation and/or expansion. In one large family, we found five family members with a large CD8 subset expansion. Remarkably similar usage of J beta regions was noted, and two individuals demonstrated V beta 3-expressing clones with homologous CDR3 regions, differing by only one major substitution. The repertoire data from this family suggest that the T cell clones have arisen in response to a common Ag. Studies of patients with rheumatoid arthritis found a significantly increased frequency of circulating CD8 subset expansions that expressed a different V region repertoire compared with the healthy individuals studied. Overall, our results emphasize a frequent alteration in the human CD8 TCR repertoire, most likely related to an environmental exposure, in both healthy individuals and patients with rheumatoid arthritis. The presence of these expansions will be important to consider in any study of human TCR repertoire, and their implication for health and disease will be important to understand.

Adolescent↗

Neurons, astrocytes, and oligodendrocytes of the rat cerebral cortex originate from separate progenitor cells: an ultrastructural analysis of clonally related cells.

The diverse array of neurons and glia in the mammalian cerebral cortex arises from proliferating cells of the ventricular zone that surrounds the lateral ventricles of the developing brain. A fundamental but unresolved question is whether the individual cells of the ventricular zone are committed to producing progeny of only one particular phenotype or whether they generate progeny of more than one phenotype. We have begun to address this question by asking if individual cells of the ventricular zone generate exclusively neurons or glia at the onset of cortical neurogenesis in the rat. To assess the phenotypes of cells derived from a common progenitor cell, retroviral-mediated gene transfer was used to introduce the reporter gene, Escherichia coli beta-galactosidase, into ventricular zone cells at embryonic day 15 or 16. We used histochemistry to reveal beta-galactosidase-expressing cells in the mature rat cerebral cortex. Isolated clusters of beta-galactosidase-expressing cells, presumably clones, were identified in serial sections. Since the histochemical reaction product is electron dense, each cell could be examined at the ultrastructural level and assigned definitively to one of the major classes of cells in the cerebral cortex on the basis of well-established morphological criteria. This approach overcomes the problems of cell type identification encountered with light microscopy, where it is not always possible to distinguish between different cell phenotypes. We found that virtually all clones contained cells of exclusively one type: either all astrocytes, all oligodendrocytes, or all neurons. Furthermore, each particular cell type exhibited a different pattern and intensity of staining. The neuronal clones, with one exception, were composed of either all pyramidal cells (projection neurons), or all nonpyramidal cells (interneurons). The size and composition of neuronal clones did not seem related to their position in the cerebral cortex. Collectively, our observations indicate that separate progenitor cells exist for pyramidal neurons, nonpyramidal neurons, astrocytes, and oligodendrocytes. The striking phenotypic homogeneity in the clones arising from individual progenitor cells suggests that by the onset of cortical neurogenesis, at least some lineage restrictions have already occurred among the precursor cell population. Thus, our results suggest that lineage may play a pivotal role in determining some of the functionally important phenotypic attributes of cells in the cerebral cortex.

Animals↗

Analysis of clonal antigen receptor gene rearrangements in T-cells involved with Kaposi's sarcoma.

Kaposi's sarcoma (KS) is a multifocal neoplasm of unknown origin. All forms of KS are composed of spindle-shaped cells with elongated nuclei and sheets of endothelial-like cells. The proliferation of spindle cells is accompanied by the presence of an inflammatory infiltrate composed predominantly of T-cells. It has been suggested that this infiltrate might consist of a virally stimulated clonal population of T-lymphocytes which can produce growth factors initiating and substaining the proliferation of spindle-shaped cells. In this study we analyzed for clonal T-cell receptor gama gene rearrangements the T-cell populations present in the cutaneous infiltrate of seven cases of classical Kaposi's sarcoma using a polymerase chain reaction-based approach. Our data demonstrate the lack of a significant clonal population of T-cells in the cutaneous infiltrates of KS. This finding is indicative of a reactive polyclonal response of T-cells to the spindle-shaped cells and supports the contention that spindle-shaped cells are pathogenetically the central cell type in the disease. Our data also indicate that the anti-KS T-cell response, being polyclonal in nature, does not result from clonal expansion of T-cells targeting tumor-associated antigenic peptides.

Gene Rearrangement, gamma-Chain T-Cell Antigen Rec↗

[Analysis of clonal origin of concomitant chronic lymphocytic leukemia and multiple myeloma in a patient with advanced age].

Concomitant chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) is a rare disease. Studies on the clonal origin of both lymphocyte and plasma cell in this disease has been few. So far it has not been reported in China. The paper reports a case of 92-year old patient with concomitant CLL and MM and the research results on the origin of lymphocyte and plasma cell by analyzing the morphologic characteristics, monoclonal antibodies, immunoglobulin Ig or TCR gene rearrangement (GR), Ig single-strand conformation polymorphsm (SSCP) fingerprint mapping and heteroduplex formation. The Ig H GR segments same in size, single strand conformation and sequence characteristics have been obtained from both peripheral blood and bone marrow DNA, even though the cells of CLL and MM had different characteristics in morphology and different secretion of IgM lambda and IgA lambda. The results suggested that the malignant cells of both CLL and MM in this patient had common origin from the B-cell.

Aged↗

Clonal expansion of gammadelta-T lymphocytes in an HTLV-I carrier, associated with chronic neutropenia and rheumatoid arthritis.

We report on an HTLV-I carrier showing clonal proliferation of gammadelta-T lymphocytes associated with chronic neutropenia and rheumatoid arthritis (RA). A 75-year-old Japanese woman had a 20-year history of RA and was found to have neutropenia and lymphocytosis by routine examinations. Her white cell count was 5,800/microl with 89% lymphocytes. The proliferating gammadelta-lymphocytes did not show the typical morphology of large granular lymphocytes (LGL) and were positive for CD3, TCRdelta1, and HLA-DR but negative for CD4, CD8, and deltaTCS1. Clonally rearranged TCRgamma-chain (Jgamma) and TCRbeta-chain (Cbeta1) genes were detected by Southern blot analysis. Clonality of these proliferating gammadelta-T cells was confirmed by CDR3 size analysis for the TCRdelta-chain. Anti-HTLV-I antibody was positive and the pX region of HTLV-I proviral DNA was detected by PCR analysis, but clonal integration of HTLV-I proviral DNA was not detected by Southern blotting analysis. The patient's clinical course has been stable, except for infrequent infectious episodes. The association of HTLV-I/II infection with T-LGL leukemia has been reported by several groups, although most cases exhibit TCRalphabeta+ type T cells. Analysis of the junctional sequence of TCR on T-LGL leukemia cells may clarify the role of HTLV-I/II infection in clonal T-cell proliferation.

Aged↗

Replacement of posterior by anterior structures in the Drosophila wing caused by the mutation apterous-blot.

The recessive mutation apterous-blot in Drosophila melanogaster causes replacement of posterior wing structures by anterior ones, with variable penetrance and expressivity. Extreme transformations resemble mirror-image duplicate anterior wings as in the mutant engrailed. Anterior structures in the posterior wing only appear on the dorsal surface. Duplications solely of posterior structures are also seen. Clonal analysis shows that extra cell proliferation occurs in the posterior area but is complete by 108 h after egg deposition. Lineage analysis is consistent with a clonal perpetuation of the transformation. Genetic mosaics to test the cell-autonomy of apterous-blot show that it is not autonomously expressed in clones. The results of lineage analysis, the phenotypes of combinations of apterous-blot with other apterous alleles including a deletion for the locus and with various other homoeotic mutations, are together used to distinguish three alternative modes of action of this mutation. It is concluded that apterous-blot is unlikely to be a selector gene mutation but instead may cause the transformation by an event like transdetermination following a local failure in cell function in the wing disc.

Animals↗

Clones of human satellite cells can express in vitro both fast and slow myosin heavy chains.

In order to test the diversification among satellite cells in man, satellite cells were isolated from human quadriceps and masseter muscles. The growth kinetics and morphological features of these cells were determined in vitro and the expression of the different myosin heavy (embryonic, fetal, fast, and slow) and light chain isoforms was analyzed. In all satellite cell cultures, only the four fast-type light chains (MLC1emb, MLC1F, MLC2F, and MLC3F) were synthesized and no slow myosin light chains were ever detected. However, we found that fused cultures of human satellite cells express both adult fast and slow myosin heavy chains (MHCs), in addition to embryonic and fetal isoforms. In order to determine if distinct fast and slow cell lineages could be detected among the satellite cells, a clonal analysis was carried out on both cell populations. This analysis was first carried out on clonal populations and was confirmed by the analysis of isolated clones. Double-labeling experiments confirmed that all myogenic clones which expressed fast MHC also coexpressed slow MHC. Therefore, we found no evidence for the existence of different fast and slow satellite cell lineages in human postnatal skeletal muscle.

Adolescent↗

The effect of T-lymphocyte 'clonality' on the calculated hprt mutation frequency occurring in vivo in humans.

The frequency of 6-thioguanine resistant (TGr) mutant T-lymphocytes arising in vivo in humans can be quantified with a cell cloning assay. However, the in vivo proliferation of T-lymphocytes that may include TGr mutant cells can distort the relationship between mutation events and the resulting frequency of mutant cells. The T-cell receptor (TCR) gene rearrangement pattern of T-cell colonies can be used as an independent measure of clonality. Analysis of T-cell 'clonality' in 413 wild type and 1736 TGr mutant isolates from 58 individuals shows that mutant clonality is a frequent occurrence (35/58 individuals = 60.3%). However, a major effect on the mutant frequency corrected for clonality (the calculated 'mutation frequency') was found only in nine samples all of which had mutant frequencies greater than 40 x 10(-6).

Autoimmune Diseases↗

A clonal study of hematopoiesis using the M27 beta probe: aberrant band patterns caused by incomplete digestion of a methyl-sensitive enzyme in the the inactive X-chromosome.

The M27 beta probe has been used to determine the clonality of human tumors, based upon X-chromosome inactivation. However, it occasionally gives rise to aberrant results. In this study, the M27 beta probe was used for clonal analysis in Japanese women with clonal stem cell disorders and in those with normal hematopoiesis. Restriction digestion with PstI indicated heterozygosity for the DXS255 locus in 41 out of 50 individuals (82%). Further digestion with HpaII in heterozygous women led to four distinct band patterns: I, both fragments were partially digested; II, either one of the two fragments was completely digested; III, a three-band pattern; and IV, neither fragment was digested. Of 21 hematologically normal females, 17 (81%) and four (19%) had patterns I and III, respectively. In some subjects with pattern I, imbalanced HpaII digestion in the two alleles was seen. Fifteen (65%) of the 23 patients with clonal stem cell disorders had pattern II, while the remainder (35%) had pattern IV. The normal tissues of three acute myeloid leukemia patients with pattern IV all revealed pattern I. It is possible that the aberrant band patterns could be caused by incomplete HpaII digestion in inactive X-chromosomes. In this study, we propose a hypothesis whereby, in normal tissues, aberrant cells, the DXS255 locus of which is not digested with HpaII despite their inactive status, would be mixed with cells demonstrating the usual methylation pattern. In normal tissues, complex of proportion of aberrant cells and skewed Lyonization could produce a variety of band patterns. If a cell with the usual methylation pattern proliferated monoclonally, pattern II would be seen: whereas if an aberrant cell proliferated, pattern IV would be demonstrated.

Blotting, Southern↗

The immune response of CBA/N mice and their F1 hybrids to 2,4,6-trinitrophenylated (TNP) antigens. I. Analysis of the response to TNP-coupled lipopolysaccharide in vivo and at the clonal level.

Plaque-forming cell (PFC) responses to 2,4,6-trinitrophenylated lipopolysaccharide (TNP-LPS) were studied in normal and immunodeficient mice. In vivo immunizations with TNP-LPS showed a 25--50% reduction in PFC responses in CBA/N mice and their (CBA/N X BALB/c)F1(NBF1) male hybrids with an X-linked immune defect of B lymphocyte differentiation. A detailed clonal analysis of the reduced responses to TNP-LPS revealed that CBA/N and NBF1 male mice with the X-linked genetic defect have fewer precursor B cells engaged in the response to TNP-LPS than the control mice. The reduction in precursor cell numbers affects selectively B cells secreting high avidity anti-TNP antibodies as determined by PFC inhibition studies.

Animals↗