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T Egeland

Publications and source records attributed to T Egeland.

At least 73 records · Page 4Linked to original sources
PubMed1995

Differential expression of receptors for interleukin-3 on subsets of CD34-expressing hematopoietic cells of rhesus monkeys.

The target cell specificity of interleukin-3 (IL-3) was examined by flow cytometric analysis of IL-3 receptor (IL-3R) expression on rhesus monkey bone marrow (BM) cells using biotinylated IL-3. Only 2% to 5% of unfractionated cells stained specifically with the biotinylated IL-3 and most of these cells were present within the CD34+ subset. IL-3Rs were detected on small CD34dull/RhLA-DRbright/CD10+/CD27+/CD2-/++ +CD20- cells, which probably represent B-cell precursors. IL-3R+ CD34- BM cells, which were detected at low frequencies, consisted of small CD20dull/surface-IgM+/RhLA-DR+ cells. These cells represented immature B lymphocytes, whereas CD20bright mature B cells were IL-3R-. The highest IL-3R levels were detected on CD34dull/RhLA-DRbright blast-like cells. These cells differentiated into monocytes, neutrophils, and basophils after IL-3 and/or granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation in vitro. The CD34bright/IL-3R- subset contained all clonogenic erythroid and myeloid progenitors (burst-forming unit-erythroid and colony-forming unit-culture), whereas CD34bright/IL-3Rdull cells differentiated into monocytes, neutrophils, and erythroid cells after shorter culture periods. This finding showed that IL-3R expression increases during monocyte and granulocyte differentiation. Results of three-color experiments indicated that IL-3Rs are expressed on CD34bright/RhLA-DRbright cells as well as on CD34bright/RhLA-DRdull cells, with the latter population expression approximately twofold to threefold lower IL-3R levels. A large fraction (> 30%) of single-cell/well-sorted CD34bright/RhLA-DRdull cells formed multilineage colonies after 2 to 4 weeks of stimulation with IL-3, GM-CSF, Kit ligand, and IL-6. Individual colonies contained cells that still expressed CD34 as well as differentiated monocytes, granulocytes, and erythroid cells. These results confirmed that the CD34bright/RhLA-DRdull subset was enriched for immature, multipotent progenitor cells, whereas the CD34bright/RhLA-DRbright population mainly contained lineage-committed precursors. The results are consistent with the concept that IL-3Rs are induced at very early stages of hematopoiesis, as identified by high expression of CD34 and low expression of RhLA-DR. IL-3R expression continues to be low during differentiation into lineage-committed progenitors; gradually increases on differentiating progenitor cells for B cells, granulocytes, monocytes, and, possibly also, erythrocytes; but finally declines to undetectable levels during terminal differentiation into mature cells of all lineages in peripheral blood, with the exception of basophils.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Binding diversity of antibodies against external and internal epitopes of the multidrug resistance gene product P-glycoprotein.

P-glycoprotein (Pgp) is a trans-membraneous protein that is associated with multidrug resistance (MDR) in human cancer, including hepatocellular carcinomas and leukemias. There is no consensus regarding methods of choice for analysis of Pgp expression, and development of reliable analytical methods is now essential. We have studied the the Pgp expression in human hepatoma and leukemia cell lines using flow cytometry. The aim of the study was to compare binding properties of anti-Pgp antibodies reacting with surface (MRK16, UIC2) and cytoplasmic (C219, JSB-1) epitopes to assess which antibody performed best with respect to fluorescence discrimination. By histogram subtraction the fractions of resistant human hepatoma cells positive for Pgp were 99% (MRK16), 97% (UIC2), 77% (JSB-1), and 51% (C219), demonstrating variations in antibody reactivity. The resolution in detecting decreasing levels of Pgp in hepatoma cells was superior for the externally binding antibodies, showing that there is a correlation between antibody reactivity and fluorescence discrimination. Similar results were obtained for parental and resistant KG1a human leukemia cell lines. The Pgp epitopes remained reactive to the anti-Pgp MAbs after methanol fixation and cryopreservation. By dual parameter flow cytometry it was shown that Pgp expression in viable cells may be assessed together with uptake of epirubicin, which was low in cells expressing high levels of Pgp and vice versa. In conclusion, all tested antibodies proved useful for flow cytometric detection of high levels of Pgp, but the externally binding ones were superior in detection of low and variable levels of Pgp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Haemopoietic progenitor cell differentiation: flow cytometric assessment in bone marrow and thymus.

We have recently shown that expression of any of the lineage-associated molecules CD2, CD7, CD10, CD19 or CD33 does not ensure lineage-commitment of CD34+ progenitor cells. Further, normal progenitor cells and leukaemic blast cells have been shown to coexpress molecules associated with more than one haemopoietic lineage. Five-dimensional flow cytometric analysis of normal bone marrow cells was exploited to investigate the hypothesis of a developmental stage in haemopoiesis comprising CD34+ cells coexpressing CD2, CD5, CD7, CD10, CD19 and CD33 or any combination of these molecules. We report on a subpopulation of CD34+ bone marrow cells constituting < 5% of the CD34+ cells and characterized by extensive coexpression of several molecules associated with the B lymphoid, T lymphoid and myeloid lineages. There is every probability that some cells display the CD34+ CD2+ CD5+ CD7+ CD10+ CD19+ CD33+ phenotype. Studies on postnatal thymocytes suggest that this may be the phenotype or one of a few phenotypes of a candidate thymus-seeding progenitor cell population. Finally, our findings that CD34+ as well as CD34+ CD5+ thymocytes can be driven into non-T-lymphoid differentiation by cytokines, support the notion that the thymus is seeded by uncommitted progenitors.

Adult↗
PubMed1995

Thymic stromal cells support differentiation of natural killer cells from CD34+ bone marrow cells in vitro.

Natural killer (NK) cells are CD3-CD56+ lymphocytes characterized by exhibiting non-MHC restricted cytotoxicity. A developmental relationship between NK cells and T lymphocytes has been proposed, and, moreover, the thymus has been shown to contain NK cell precursors. In this study we utilized an in vitro assay, devised to study T-lymphocyte development from bone marrow progenitors, to investigate the ability of thymic stromal cells to support generation of NK cells from CD34+ bone marrow cells. CD34+ cells purified from healthy adults were seeded on adherent thymic stromal cells. The cells emerging after culture were phenotypically characterized by flow cytometry. We show that lymphocytes expressing the phenotypical characteristics of NK cells were generated from CD34+ bone marrow cells, and that these cells represented 1% of the cells recovered from the cultures. Furthermore, this was accomplished without supplement of exogenous interleukin 2 which is required for NK cell differentiation in bone marrow cultures.

Adult↗
PubMed1995

[Stem cell transplantation--more than bone marrow transplantation].

Allogeneic transplantation of peripheral blood haematopoietic stem cells is gradually becoming an alternative to bone marrow transplantation (BMT), probably because of its convenience for the donor; i.e. the donor does not need to be hospitalised and there is less post-harvesting discomfort. Preliminary findings suggest that the two treatment modes do not differ in time to engraftment or the incidences of rejection and graft-versus-host disease. However, the effects of peripheral blood stem cell transplantation on long-term survival, duration of haematopoiesis, and clinical outcome in cases of unrelated donors with or without certain degrees of HLA mismatch remain to be established. Moreover, transplantation with umbilical cord blood, being rich in haematopoietic stem cells, is another alternative to BMT, particularly in small children.

Bone Marrow Transplantation↗
PubMed1994

Evidence for engraftment of donor-type multipotent CD34+ cells in a patient with selective T-lymphocyte reconstitution after bone marrow transplantation for B-SCID.

Severe combined immunodeficiencies (SCID), a heterogeneous group of disorders of infancy, are fatal without treatment directed at immunologic reconstitution. Allogeneic bone marrow transplantation (BMT), which is such a treatment presents some unique features in SCID, especially when T-lymphocyte-depleted HLA haploidentical allografts are used. Donor-type T lymphopoiesis, less often B lymphopoiesis, develops, whereas myelopoiesis remains the recipient-type. Little is known about the engrafting cells in this peculiar lymphohematopoietic chimerism and the pathophysiology of the frequent failure of B-lymphocyte reconstitution. To address these issues, we purified CD34+ BM cells from a patient with selective T-lymphocyte reconstitution after HLA haploidentical BMT for B-SCID. Phenotypic analysis of CD34+ cells was performed by flow cytometry, and functional studies of donor- and recipient-type CD34+ cells were performed in vitro. Donor-type CD34+ cells, constituting approximately 2% of the CD34+ cells, were detected; both CD34+ HLA-DR- cells and CD34+ cells coexpressing B-(CD10 and CD19) and T-(CD2 and CD7) lymphocyte-associated cell surface molecules. Donor-type CD34+ cells coexpressing myeloid-associated molecules (CD13, CD14, CD15, and CD33) were undetectable. However, donor-type CD34+ myeloid progenitors could be shown in functional assays. Recipient-type CD34+ cells coexpressing B- and T-lymphocyte- as well as myeloid-associated molecules were detected, but recipient-type CD34+ cells could not be driven into T-lymphocyte differentiation in vitro. These findings provide evidence for engraftment of multipotent stem cells in our patient with B-SCID. Furthermore, the failure of B-lymphocyte reconstitution cannot be explained by lack of donor-type B-lymphocyte progenitors. Donor-type B lymphopoiesis and myelopoiesis are prevented by an unidentified mechanism.

Antibodies, Monoclonal↗
PubMed1994

Characterization of CD34+ peripheral blood cells from healthy adults mobilized by recombinant human granulocyte colony-stimulating factor.

Primed peripheral blood hematopoietic stem cells (PBSC) generate and sustain lymphohematopoiesis in myeloablated animals, and recent reports indicate that allogeneic transplantation using PBSC grafts may be feasible in humans. A major concern with the use of PBSC transplants is that permanent engraftment may be limited because of lack of sufficient numbers of primitive progenitor cells in the graft. In the present study, in vitro colony formation and immunophenotype of CD34+ cells in PB of healthy adults during short-term granulocyte colony-stimulating factor (G-CSF) administration were compared with that of CD34+ cells in normal bone marrow (BM). The number of CD34+ cells mobilized to PB peaked at day 4 or 5 of G-CSF administration. The phenotypic profile of CD34+ PB cells showed a substantial increase in the percentage of CD34+CD13+ and CD34+CD33+ cells (myeloid progenitors) and a corresponding decrease in the percentage of CD34+CD10+ and CD34+CD19+ cells (B lymphoid progenitors) compared with CD34+ BM cells. The other subsets studied, including CD34+CD38- and CD34+HLA-DR- cells, were present in both compartments in similar proportions. Furthermore, primed CD34+ PB cells were enriched for colony-forming cells (CFC) and displayed an increased clonogenicity when compared with their counterparts in BM. A comparison between a postulated PBSC graft and an average BM graft is presented, showing that such PBSC grafts will be enriched for CD34+ cells as a whole, CD34+CD33+ cells, and colony-forming cells (CFC), factors which have been shown to correlate to acceleration of hematologic reconstitution and reduction in requirements for supportive care in autografting. Hence, we predict that allogeneic transplantation using G-CSF-primed PBSC grafts will result in a more rapid hematologic reconstitution after myeloablative conditioning than BM grafting. The question of whether PBSC allografting will result in permanent engraftment and clinical benefits as observed in autografting has to be determined in prospective clinical studies.

ADP-ribosyl Cyclase↗
PubMed1994

[Infusion of hematopoietic stem cells from the blood. Simpler and better than bone marrow transplantation?].

Infusion of haematopoietic stem cells, either autologous or allogeneic, allows treatment of malignant diseases with marrow ablative doses of cytostatics or whole body irradiation. Hospitalization and general anaesthesia is necessary for bone marrow harvesting, while the harvest of peripheral stem cells may be performed without hospitalization. Mobilization of haematopoietic stem cells from the bone marrow to peripheral blood, followed by cytapheresis and harvesting of the stem-cell containing fraction is a promising alternative to the harvest of marrow. We have tried this in one patient with advanced acute myeloid leukaemia and discuss our experience and that of others.

Blood Transfusion, Autologous↗
PubMed1994

[Transplantation immunology in allogeneic bone marrow transplantation. The significance of HLA-tissue crossmatching between donors and recipients].

We describe our current programme for donor-patient HLA matching. First, the patient and family members are serologically typed to define HLA haplotypes and to search for HLA genotypically identical siblings. If no HLA identical siblings can be found, we search for a haploidentical family donor with zero or at most one HLA molecule mismatch on the non-shared haplotype. Secondly, we search for an HLA identical unrelated donor in the Norwegian and foreign bone marrow donor registers. For final matching of patient and unrelated or haploidentical donors, we include genomic typing of DRB1, DQB1, and DPB1 alleles by sequence-specific oligonucleotide probing or direct sequencing.

Bone Marrow Transplantation↗
PubMed1994

c-kit ligand combined with GM-CSF and/or IL-3 can expand CD34+ hematopoietic progenitor subsets for several weeks in vitro.

It might be possible to facilitate engraftment after transplantation of purified hematopoietic progenitor cells if the cells are stimulated ex vivo prior to transplantation. The aim of this study was to analyze the potential of c-kit ligand (CKL) combined with granulocyte-macrophage colony-stimulating factor (GM-CSF) and/or interleukin-3 (IL-3) to induce proliferation and differentiation of human bone marrow CD34+ cells in vitro. Particular attention was paid to the ability to expand populations that could maintain progenitor characteristics, i.e. CD34 expression and generation of colony forming cells (CFC), for a considerable period of time. Purified CD34+ cells were cultured in liquid medium for 42 days interrupted by immunophenotyping and CFC assays. In the presence of CKL combined with GM-CSF and/or IL-3, the total number of cells expressing CD34 increased significantly for several weeks after an initial decline. Further, CFC were continually recovered in these cultures. Based on the kinetics and the flow cytometry analysis, the expanding populations that continued to express CD34 probably originated from noncommitted, immature CD34+ cell subsets. CKL combined with GM-CSF and/or IL-3 also induced strong cell proliferation. The majority of the proliferating cells lost CD34 expression and acquired a series of mature myeloid cell surface markers associated with the monocytic, granulocytic and megakaryocytic lineages. These cells probably originated from committed CD34+ cell subsets. We conclude that CKL combined with GM-CSF and/or IL-3 can stimulate noncommitted, immature as well as committed CD34+ cell populations to expand and to differentiate. This property might be useful in a short-term ex vivo pretransplant stimulation of CD34+ cells in an attempt to facilitate rapid and stable engraftment after stem cell transplantation.

Adult↗
PubMed1994

Comparison of the phenotype and clonogenicity of normal CD34+ cells from umbilical cord blood, granulocyte colony-stimulating factor-mobilized peripheral blood, and adult human bone marrow.

Bone marrow (BM) is most frequently used to transplant hematopoietic progenitor cells, but umbilical cord blood (UCB) and mobilized peripheral blood (PB) provide alternative sources of progenitor cells for transplantation. To study whether the clonogenicity and phenotype of progenitor cells vary between the compartments, CD34+ cells from UCB, mobilized PB, and BM were analyzed for in vitro colony formation and characterized by immunophenotyping for several lineage-associated and maturation-related cell surface molecules. We found that circulating CD34+ cells, either from PB after granulocyte colony-stimulating factor (G-CSF) mobilization or from UCB, contained a large proportion of cells (86-96%) with myeloid cell-associated molecules (CD33 and CD13) and clonogenic cells (colony-forming unit-granulocyte-macrophage and burst-forming unit-erythrocyte) in excess of BM CD34+ cells. Further, UCB and PB CD34+ cells contained > or = 3% cells with a phenotype associated with immature (HLA-DR- and CD38-) progenitor cells, which was comparable to what is found among BM CD34+ cells. The proportion of CD34+ cells in UCB expressing the B cell-associated molecules (CD10 and CD19) was comparable to that found in mobilized PB (< or = 5%) but significantly lower than for BM CD34+ cells (19-24%). Further, we observed a higher proportion of CD34+ cells expressing the T cell-associated molecule CD7+ in UCB (7%) compared with both PB and BM (3-4%). In general, circulating CD34+ cells, either from UCB or G-CSF-mobilized PB, display largely the same phenotypic profile and clonogenicity, being different from resident CD34+ cells in BM.

ADP-ribosyl Cyclase↗
PubMed1994

Expression of costimulatory molecule CD28 on T cells in human immunodeficiency virus type 1 infection: functional and clinical correlations.

To study the functional integrity of T cells from human immunodeficiency virus type 1 (HIV-1)-infected persons, CD4+ and CD8+ cells were examined for proliferation and secretion of interleukin-2 (IL-2) in response to staphylococcal superantigens and antibodies to CD3 and the alpha beta T cell receptor. A functional defect within CD8+ but not within CD4+ cells from HIV-1-infected persons was observed. Within CD8+ cells, proliferation and secretion of IL-2 was restricted to cells expressing the costimulatory molecule CD28. Such cells were proportionally reduced in HIV-1-infected persons. In patients with advanced immunodeficiency, however, evidence of functional derangement was found also within the CD28+ CD8+ cells. In a cross-sectional study of 73 HIV-infected persons and 15 controls, a significant correlation was observed between the number of CD28+ CD8+ cells and the presence of HIV-related disease. Our results suggest that regulation of expression of CD28 may play an important role in the immunopathogenesis of AIDS.

CD28 Antigens↗
PubMed1993

T lymphocyte differentiation in vitro from adult human prethymic CD34+ bone marrow cells.

Pluripotent lymphohematopoietic stem cells are probably confined to bone marrow cells expressing CD34 surface molecules. To investigate the capacity of adult human CD34+ bone marrow cells to differentiate along the T lymphoid lineage, we plated purified CD34+ cells from healthy adults in liquid culture on adherent thymic stromal cells prepared from HLA- or blood group-mismatched postnatal thymic tissue. We show that purified CD34+CD3-CD4-CD8- bone marrow cells contained progenitors with the ability to differentiate into CD4+ and CD8+ T lymphocytes expressing surface (s)CD3 and T cell receptor alpha/beta in vitro. These progenitors were found in the CD34+CD2+sCD3-CD4-CD8-, CD34+CD7+sCD3-CD4-CD8-, and CD34+CD2+CD7+sCD3-CD4-CD8-, as well as in the CD34+CD2-sCD3-CD4-CD8-, CD34+CD7-sCD3-CD4-CD8-, and CD34+CD2-CD7-sCD3-CD4-CD8- subsets, indicating that T lymphocyte progenitors sensitive to signals mediated by thymic stroma in vitro are not restricted to CD34+ cells already coexpressing early T lymphocyte-associated markers. Finally, we show that T lymphopoiesis was enhanced by c-kit ligand.

Adult↗
PubMed1993

HLA-DR1 and rheumatoid arthritis in Israeli Jews: sequencing reveals that DRB1*0102 is the predominant HLA-DR1 subtype.

Rheumatoid arthritis (RA) is associated with the HLA-DR4 cellular subtypes Dw4 and Dw14 in Caucasians, with Dw15 in Japanese, and possibly with HLA-DR1 in Israeli Jews. Sequencing studies in Caucasians have shown that these molecules share a common amino acid sequence in the third hypervariable region of the DR molecule (AA 67-74: LLEQRRAA or LLEQKRAA), suggesting that this sequence is primarily associated with RA. An important argument in favor of this shared-epitope hypothesis has been the reported association between DR1 and RA in Israeli Jews. However, a later report did not confirm this association, and cellular typing showed that Israeli DR1 consists of three or more subtypes, suggesting that new subtypes might be present. Since no sequencing data on Israeli HLA-DR1 genes have been reported, we sequenced the first domain (AA 10-91) of the DRB1 gene in 12 DR1-positive Israeli RA patients, 5 healthy controls and a homozygous typing cell (HTC), defining the major Jewish cellular HLA-DR1 subtype. DRB1*0102 (DR1 Dw20) was found in 8 RA patients, 3 controls and the HTC "LVA". DRB1*0101 (DR1 Dw1) was found in 4 RA patients and 2 controls. No other DR1 subtypes were encountered. In all 20 DR1 haplotypes, the DRB1*0101 or 0102 allele was associated with DQA1*0101 and DQB1*0501, being identical to the Caucasian DR1 haplotypes. Thus, at the sequence level, we found no basis for the reported extensive cellular heterogeneity of DR1 in the Israeli population.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1993

HLA matching of unrelated bone marrow transplant pairs: direct sequencing of in vitro amplified HLA-DRB1 and -DQB1 genes using magnetic beads as solid support.

Sequencing of HLA genes can offer complete information on the HLA class II genes relevant for the outcome of bone marrow transplantation (BMT). Genomic HLA matching of unrelated BMT patient/donor pairs is often based on PCR-SSO typing of HLA class II alleles. Typing a small number of samples by this approach is both expensive and time-consuming, due to the large number of SSO probes required to perform a complete class II typing. Moreover, only polymorphisms explicitly tested for will be found. We now provide the first report of the use of direct sequencing of HLA-DRB1 and -DQB1 genes, using PCR-amplified genomic DNA attached to magnetic beads, for clinical routine HLA matching. Sequencing ladders obtained by this procedure are easily readable, the patterns can be interpreted in HLA homozygous as well as heterozygous individuals, and sequence differences or similarities between the BMT donor and recipient can be directly identified. This genomic typing method is informative, relatively fast and therefore well-suited for the small number of samples usually analyzed in matching of BMT pairs. Furthermore, this technique has the potential for automation.

Base Sequence↗
PubMed1992

Isolation and characterization of human hematopoietic progenitor cells: an effective method for positive selection of CD34+ cells.

Immunomagnetic beads are well suited for positive selection of CD34+ cells. However, both unspecific binding of beads to cells as well as the effectiveness of detachment of beads from cells may represent significant problems. We used an anti-Fab antiserum (DETACHaBEAD, Dynal) for rapid and effective detachment of immunomagnetic beads from the positively selected cells. By this detachment technique, the cells remained phenotypically unaltered. To reduce unspecific binding, we have coated various anti-CD34 monoclonal antibodies directly to paramagnetic beads M450 (Dynal). Use of beads coated with BI-3C5 was found to be optimal with regard to yield and purity of the isolated cells. The yield was on average 1.5% (range 0.5-2.5%) of bone marrow mononuclear cells and the purity was usually greater than 95% CD34+ cells of the isolated cells. Subpopulations of the cells expressed myeloid markers (CD13, CD33, and to a lesser extent CD15 and CD14) or early B-lineage markers (CD19 and CD10). Most of the cells expressed CD38, and a majority of the cells also expressed CD41. In general, most of the CD34+ cells with low forward scatter expressed B-lineage markers, as was also the case for the few contaminating CD34- cells which were found to be predominantly CD37+ mature B cells. Reactivity with antibodies against T-lineage markers (CD2, CD3, CD4, CD7, and CD8) was generally detected only on 1-2% of the cells or less. Isolated cells responded to interleukin 3, granulocyte-macrophage colony-stimulating factor, mast cell growth factor, and/or granulocyte colony-stimulating factor alone or in combinations in short-term liquid cultures. The cells were also markedly enriched for granulocyte-macrophage colony-forming units as well as for early progenitor cells capable of forming blast colonies on preformed stromal feeder layers. Moreover, the CD34- population was depleted of 70-80% of CFU-GM and cells capable of blast colony formation. Thus, we conclude that the isolated cells are phenotypically unaltered after isolation, and show a normal response in various in vitro assays.

Antigens, CD↗