B Jahn

Johannes Gutenberg-Universität Mainz, Mayence, Rheinland-Pfalz, Germany

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Publications (15)61.14 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Treatment of patients in remission of acute myelocytic leukemia using immunotherapy with interleukin 2 is a new approach to prolonging remission duration in this disease. As an important mechanism for the pathophysiology of eradication of residual myelocytic blast populations, activation of cytotoxic effector lymphocytes has frequently been discussed. However, the associated immunological research has been complicated to some extent, because in conventional chromium 51-release assays, blast cells frequently fail to incorporate sufficient amounts of 51Cr and/or spontaneously release high amounts of 51Cr. Recently, we established a culture system which promotes the outgrowth of cytotoxic T lymphocytes in bone marrow-derived mononuclear cells cultured in IL-2. To study cytotoxicity and the responsible mechanisms of the obtained T-cell lines and clones, we modified a previously described cytotoxicity assay, based on the release of lactate dehydrogenase (LDH-release assay) for use in cryopreserved blasts obtained from the bone marrow of patients with acute myelocytic leukemia. Using this assay, we were able to detect cytotoxicity of IL-2-activated peripheral blood lymphocytes from three healthy controls against a number of blast samples obtained from the bone marrow of patients with AML (up to more than 40% lysis at an effector target cell ratio of 20:1). However, a minority of AML blasts seem to be resistant to lysis by IL-2-activated lymphocytes. In bone marrow-derived T-cell lines from patients with AML we detected lytic activity against autologous blasts in three of seven cases tested by LDH release, ranging from 29 to 63% at an effector target ratio of 10:1. Additionally, T-cell clones with different phenotypes were established which were able to mediate cytotoxicity against autologous blast cells. Thus, cytotoxicity against freshly isolated blasts from patients with acute myelocytic leukemia can be analyzed reliably, reproducibly, and without the use of isotopes by the LDH-release assay.
    Annals of Hematology 04/1995; 70(3):153-8. · 2.87 Impact Factor
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    ABSTRACT: The eradication of minimal residual blast populations by activation of autologous cytotoxic cells with interleukin 2 (IL-2) is a new promising tool in the treatment of acute myelocytic leukemia (AML). However, the immunological effector cells are not yet clearly defined. The present study was designed to investigate the presence of cytotoxic precursor cells in active AML and to identify phenotypical and functional characteristics of autologous anti-leukemic cytotoxic effector cells. For this purpose, mononuclear cells (MNC) containing at least 70% leukemic blasts were isolated from bone marrow of untreated AML and cultured in the presence of 3000 IU/ml recombinant IL-2 (rIL-2) for 6-8 weeks. Under these conditions, T-cells were selected in the bone marrow cultures and overgrew the leukemic blasts. The resulting T-cell populations were cloned by limiting dilution and the clones obtained were characterized for their phenotypical and functional patterns. Totally, cloning resulted in 68 clones and a few cell lines. The clonality was verified by RT PCR analysis of TCR V beta gene expression. All clones obtained stained positive for CD2, CD3, DR and CD56. The vast majority (68%) of T-cell clones/lines was CD4+, a few clones expressed CD8 (19%) or CD4 and CD8, and four clones were of TCR gamma delta origin. Seven of 15 clones tested, including three CD4+, two CD8+ and two TCR gamma delta(+)-clones were found to be cytotoxic against autologous leukemic blast cells. All except one clone expressed oncolytic activities against allogeneic blasts too. One of the TCR gamma delta(+)-clones demonstrated NK activity by lysis of K562 targets. The majority of the T-cell-clones released IL-2, IL-8, TNF-alpha, GM-CSF but only a few IFN gamma and expressed high levels of mRNA for IL-2, TGF-beta and IL-10. None of the clones was found to produce IL-3, IL-4, IL-7 and TNF-beta. The data provide evidence of the existence of T-cell precursors in untreated AML bone marrow differentiating to cytotoxic cells with activity against autologous and allogeneic AML blast cells.
    Leukemia Research 03/1995; 19(2):73-82. · 2.76 Impact Factor
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    ABSTRACT: Recombinant interleukin-2 (rIL-2) in combination with recombinant interferon alpha (rIFN alpha) has been shown to mediate significant antitumoral effects in some patients with advanced renal cell cancer or malignant melanoma. The therapeutic effects may be partially modulated by secondarily induced cytokines, especially with regard to in vivo lymphocyte activation. To investigate possible negative effects on lymphocyte activation during immunotherapy, we designed a study on transcription of transforming growth factor beta 1 (TGF beta 1), a known inhibitor of lymphocyte function, in patients undergoing treatment with daily alternating administration of rIFN alpha and rIL-2. Here we present data on gene expression of TGF beta 1. Kinetic mRNA studies revealed an increase of TGF beta 1 mRNA in peripheral mononuclear cells 12 h after subcutaneous injection of rIFN alpha. The following intravenous rIL-2 administration significantly decreased the amounts of TGF beta 1-specific mRNA. In contrast to the effect of the first dose, subsequent application of rIFN alpha did not enhance TGF beta gene expression during rIFN alpha/IL-2 therapy. The diminished TGF beta 1 gene expression returned to pretreatment levels 1-7 days after the last rIL-2 administration. When concomitant with a decrease in TGF beta 1 transcripts. Our results indicate a complex regulatory effect on secondarily induced cytokines such as TGF beta 1 by immunotherapeutic approaches. The rIL-2-mediated down-regulation of increased TGF beta 1 steady-state mRNA levels following rIFN alpha may represent a positive immune regulatory effect on cytotoxic cells. Furthermore this effect may modulate proliferation of neoplastic tissues.
    Cancer Immunology and Immunotherapy 06/1994; 38(5):304-10. · 3.64 Impact Factor
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    ABSTRACT: Recombinant interleukin-2 (rIL-2) in combination with recombinant interferon (rIFN) has been shown to mediate significant antitumoral effects in some patients with advanced renal cell cancer or malignant melanoma. The therapeutic effects may be partially modulated by secondarily induced cytokines, especially with regard to in vivo lymphocyte activation. To investigate possible negative effects on lymphocyte activation during immunotherapy, we designed a study on transcription of transforming growth factor 1 (TGF1), a known inhibitor of lymphocyte function, in patients undergoing treatment with daily alternating administration of rIFN and rIL-2. Here we present data on gene expression of TGF1. Kinetic mRNA studies revealed an increase of TGF1 mRNA in peripheral mononuclear cells 12 h after subcutaneous injection of rIFN. The following intravenous rIL-2 administration significantly decreased the amounts of TGF1-specific mRNA. In contrast to the effect of the first dose, subsequent application of rIFN did not enhance TGF gene expression during rIFN/IL-2 therapy. The diminished TGF1 gene expression returned to pretreatment levels 1–7 days after the last rIL-2 administration. When IL-2 expression was studied, increase in IL-2 mRNA was concomitant with a decrease in TGF1 transcripts. Our results indicate a complex regulatory effect on secondarily induced cytokines such as TGF1 by immunotherapeutic approaches. The rIL-2-mediated down-regulation of increased TGF1 steady-staty-state mRNA levels following rIFN may represent a positive immune regulatory effect on cytotoxic cells. Furthermore this effect may modulate proliferation of neoplastic tissues.
    Cancer Immunology and Immunotherapy 01/1994; 38(5):304-310. · 3.64 Impact Factor
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    ABSTRACT: Both interleukin-2 (IL-2) and alpha-interferon (alpha-IFN) have some efficacy in renal cell cancer (RCC) as single agents. Additionally, there is some evidence for additive or synergistic antitumoral activity of IL-2 and alpha-IFN in vitro and possibly in vivo. Based on these data, the authors initiated a Phase II trial with a combination of recombinant IL-2 (rIL-2) and recombinant alpha-IFN (alpha-rIFN) in advanced RCC. Thirty-six assessable patients with metastatic RCC were entered in this Phase II trial using a daily alternating schedule of alpha-rIFN and rIL-2. Over a period of 14 days, the patients received daily alternating treatment with 10 x 10(6) IU/m2 of recombinant alpha-2b-interferon subcutaneously and 18 x 10(6) IU/m2 of rIL-2 as a 1-hour intravenous infusion. This treatment schedule was repeated every sixth week up to a maximum of four cycles. After the second cycle, patients were examined for response. Patients with stable disease or better received two additional cycles of therapy. Patients with progressive disease were available for other strategies. Thirty-six patients entered the trial and were assessable for toxic effects. Thirty of 36 patients completed at least two cycles and were assessable for response. Nine patients achieved an objective response: 2 had complete responses (CR) and 7 had partial responses (PR). Three patients had a minor response. No effect was observed in patients with local relapse or bone metastases. A relapse-free survival length of 6 months or longer was seen in both patients with CR (12, 23 + months) and in four of seven patients with PR (6, 7, 12, 12 months). The toxicity was moderate and included fever and nausea in most patients, and hypotension, fatigue, skin rash, and arthralgia in a minority of the patients. No Grade 4 and only occasionally Grade 3 toxicity was observed. Fluid retention was negligible. The monitoring of immunologic parameters showed a significant rebound lymphocytosis including cytotoxic (CD56+) cells; in responders the peak of lymphocytosis occurred up to 1 week later than in nonresponders. Peripheral lymphocytes obtained after therapy showed only a slight increase of natural killer cell and lymphokine-activated killer cell activity. During therapy, there was a great release of secondary cytokines as tumor necrosis factor-alpha, gamma-interferon, and interleukin-6, with a peak level 2-4 hours after rIL-2 infusion. In conclusion, daily alternating administration of alpha-rIFN and rIL-2 is effective in RCC with less toxicity, and the response rate is comparable to those of other immunotherapeutic schedules, including adoptive immunotherapeutic schedules, including adoptive immunotherapy and combinations of high-dose IL-2 and alpha-IFN.
    Cancer 10/1993; 72(5):1733-42. · 5.20 Impact Factor
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    ABSTRACT: Fludarabine monophosphate is a new adenine nucleoside analogue with a promising efficacy in B-cell chronic lymphocytic leukemia (B-CLL) with response rates, including hematological complete remissions, of 50%-60% in previously treated and 75%-80% in previously untreated patients. Here, the clinical experience with and side effects of fludarabine are reported in 19 patients with refractory CLL (17 B-CLL, 2 T-CLL). All patients were pretreated with one to four different regimens and had progressive disease. Fludarabine was administered at a dosage of 25 mg/m2 daily for 5 days as a 30-minute intravenous infusion. This course was repeated every fifth week. Dosage and time course were adapted to toxicity. 12/18 (67%) evaluable patients achieved partial remissions (PR), 1/18 (6%) had stable disease (SD) and 5/18 (28%) were progressive. The median duration of partial remission until relapse or death was 6 months. Most responses to fludarabine occurred within two treatment courses. Major toxic effects included infections in 11 patients and nausea in 8 (mainly grade 1). Meanwhile, three patients died of progressive disease and 8 of pneumonias or other infections. Two patients had pneumocystis carinii pneumonias and one an aspergillus pneumonia. The high infection rate may be due not only to hypogammaglobulinaemia or fludarabine-induced granulocytopenia but also to a remarkable decrease of CD4(+)-cells during fludarabine therapy. In one case a tumor lysis syndrome was observed. No CNS toxicity was noted. It is concluded that fludarabine is effective even in patients with advanced chronic lymphocytic leukemia refractory to multiple chemotherapy regimens. However, fludarabine has a remarkable suppressive effect on T-lymphocytes, predominantly CD4(+)-lymphocytes. Long-term antibiotic prophylaxis is recommended.
    Annals of Oncology 06/1993; 4(5):371-5. · 7.38 Impact Factor
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    ABSTRACT: It is postulated that chondrocytes may be actively involved in the pathogenesis of inflammatory joint diseases, presumably by providing tissue specific antigens that may initiate or sustain autoimmune reactions. To investigate whether chondrocytes may also function as accessory cells in ongoing immune processes, mixed leukocyte-chondrocyte cultures and antigen presentation assays were studied. Freshly isolated and short term cultured HLA class II antigen (Ia) negative as well as gamma-interferon treated Ia positive chondrocytes were weakly or not stimulatory to allogeneic or autologous resting lymphocytes derived from either normal donors or patients with rheumatoid arthritis. In an antigen presenting system using tetanus toxoid, the majority of chondrocyte preparations tested induced an antigen driven response in HLA matched allogeneic or autologous resting T cells which, however, was much less when compared to blood monocytes. In contrast, using activated T cells derived from tetanus toxoid specific T cell lines, an efficient antigen presenting capacity could be demonstrated in both Ia positive and initially Ia negative chondrocytes. Interestingly, the latter population had acquired Ia antigens upon incubation with the T cell line.
    The Journal of Rheumatology 04/1991; 18(3):414-21. · 3.26 Impact Factor
  • Springer Seminars in Immunopathology 02/1989; 11(3):259-72. · 4.17 Impact Factor
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    ABSTRACT: The presence of activated T lymphocytes bearing interleukin 2 (IL-2) receptors and HLA class II (Ia) antigens accompanied by impaired T cell functions such as a decreased mitogenic responsiveness are characteristic findings, especially in intra-articular sites in chronic inflammatory joint diseases. The objective of the present study was to further characterize these in vivo activated T cells by the investigation of IL-2 production and a possible T cell receptor modulation. IL-2 receptors were found to be expressed primarily in the CD4+ subset. The Ia+ subset expressing both DR and DQ antigens showed a weaker mitogen-induced response as compared to the Ia- fraction. A decreased mitogen-induced IL-2 production and a lower response to anti-CD3 monoclonal antibodies was observed with synovial T lymphocytes as compared to peripheral blood T cells. The density of the CD3 molecule, known to be closely associated with the T cell receptor, was significantly lower in intra-articular sites, while other T cell-specific surface molecules were expressed to a similar extent in both compartments. The decreased synovial T cell mitogenesis was not restored by the addition of lymphokines (IL-1 and IL-2) or blood monocytes, nor by removing CD8+ T cells. These data present further evidence for a significant T cell activation in intra-articular sites in chronic inflammatory joint diseases. The decreased expression of the CD3 glycoprotein suggests a modulation by so far unidentified antigen(s), which could also be responsible for the weak T cell response elicited by polyclonal mitogens.
    Scandinavian Journal of Immunology 01/1988; 26(6):745-54. · 2.20 Impact Factor
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    ABSTRACT: The differential expression of Ia antigens was studied in freshly isolated rheumatoid nonlymphoid synovial lining cells (SLC) and rheumatoid synovial fibroblast cell lines cultured in the presence of Interferon-gamma, using a large panel of anti-Ia reagents with monomorphic or polymorphic specificities. All the HLA-DR or -DQ specificities detectable on the corresponding peripheral blood B cells were also expressed in freshly isolated SLC. However, in all instances, the number of DR-positive SLC exceeded the percentage of cells expressing DQ antigens. In addition, the epitope expression of Ia antigens varied within the DR or DQ populations of Ia molecules as revealed by polymorphic reagents. Double-label experiments or using the ingestion of Latex particles as a marker demonstrated that the synovial macrophages (type I SLC) primarily bear the DR+DQ+ phenotype, while there is an additional population of nonphagocytic SLC (previously termed type II SLC) that has a DR+ and monocyte marker negative phenotype but did not have detectable levels of DQ antigens as analyzed by both fluorescence microscopy and cell sorter analysis. This latter population frequently had a morphology showing dendritic processes and rapidly lost the expression of Ia antigens upon culture. Cells with a similar, primarily DR+ phenotype were readily obtained in synovial fibroblast cultures after treatment with Interferon-gamma. These data suggest that there are two populations of Ia+ synovial lining cells: the synovial macrophages (type I cells) with the DR+DQ+ phenotype, and cells probably related to fibroblasts with a DR+ phenotype without detectable DQ antigens (type II cells). The fact that the latter phenotype could be induced by Interferon-gamma treatment of cultured synovial fibroblasts suggests that this mediator may have a similar role in vivo in the activation of certain synovial cell populations.
    Journal of Clinical Investigation 10/1987; 80(3):595-604. · 12.81 Impact Factor
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    ABSTRACT: T lymphocyte subpopulations and the expression of T cell activation antigens were determined in peripheral blood, synovial fluid and/or synovial tissues of patients with recurring monoarticular arthritis and patients with HLA-B27 associated oligoarthritis in comparison to patients with rheumatoid arthritis (RA). In individuals with monoarthritis or oligoarthritis, there was a normal T cell subset distribution, both in peripheral blood and in intraarticular sites, with only a small number of T cells bearing Ia antigens. This was in marked contrast to the patient group with RA that demonstrated a significantly decreased ratio of T helper/inducer to T suppressor/cytotoxic cells in addition to large numbers of Ia+ T cells in intraarticular sites. The expression of the Tac antigen was similar in all disease groups.
    The Journal of Rheumatology 05/1986; 13(2):254-8. · 3.26 Impact Factor
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    ABSTRACT: Elevated numbers of non-blastoid T cells expressing either the Tac or Ia antigens were found on separate cell populations in inflammatory synovial tissues and fluids of individuals with arthritis. Those synovial T cell preparations containing Tac+ cells exhibited marked proliferation upon the addition of IL 2 without concomitant mitogen stimulation; T cell eluates containing Ia+ but not Tac+ T cells did not show significantly increased levels of blastogenesis. Paired T cell preparations from blood had only minor increases in the number of Tac+ T cells and moderate increases in the number of Ia+ cells. The blood cells did not exhibit significant proliferation to IL 2. In contrast mitogen or allogeneic activation of T cells induced blastoid cells that expressed abundant per cell amount of Ia or Tac antigens. These blastoid cells resembled the small T cells of inflammation in having only very limited overlap between the population that bore Ia antigens and those with the Tac antigen; however, there was a preponderance of Tac-bearing cells.
    The Journal of Immunology 10/1984; 133(3):1230-4. · 5.52 Impact Factor
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    ABSTRACT: Interactions of autologous or allogeneic T cells with non-lymphoid synovial cells were investigated to study the mechanisms of T-cell activation in rheumatoid arthritis. The synovial cell fraction obtained by Percoll gradients contained an average of 31% cells positive for monocyte antigens and 62% intensely Ia-positive cells. Tissue cultures demonstrated large numbers of cells with a dendritic morphology. Mixed leukocyte reaction (MLR) cultures between these synovial cell preparations and autologous or allogeneic peripheral blood T cells as responder cells revealed low T-cell responsiveness with an average of 3900 dpm or 17 800 dpm, respectively, in contrast to 16 900 dpm or 79 600 dpm, using rheumatoid peripheral blood non-T cells (P less than 0.01), despite equivalent amounts of Ia antigens on both stimulator populations, as determined by cell-sorter analysis. The addition of indomethacin to these synovial cell/T cell co-cultures resulted in an enhancement of T-cell responsiveness; however, this increase did not reach statistical significance due to large test variations. Co-cultures of non-lymphoid synovial cells and PHA-stimulated autologous T cells induced a marked inhibition of T-cell proliferation that could partially be reversed by the addition of indomethacin. The reduction of monocyte-antigen-positive cells by depletion of iron phagocytic cells did not result in a significant enhancement of T-cell responsiveness. These data demonstrate that the majority of non-lymphoid synovial cells, despite the presence of large amounts of Ia-antigens, are not potent inducers of T-cell proliferation and strong suppressing cells in polyclonal T-cell activation. These effects do not appear to reside in the macrophage fraction alone and can only partly be attributed to the action of prostaglandins.
    Rheumatology International 02/1984; 4 Suppl:31-7. · 2.21 Impact Factor
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    ABSTRACT: Interactions of autologous or allogeneic T cells with non-lymphoid synovial cells were investigated to study the mechanisms of T-cell activation in rheumatoid arthritis. The synovial cell fraction obtained by Percoll gradients contained an average of 31% cells positive for monocyte antigens and 62% intensely Ia-positive cells. Tissue cultures demonstrated large numbers of cells with a dendritic morphology. Mixed leukocyte reaction (MLR) cultures between these synovial cell preparations and autologous or allogeneic peripheral blood T cells as responder cells revealed low T-cell responsiveness with an average of 3900 dpm or 17 800 dpm, respectively, in contrast to 16 900 dpm or 79 600 dpm, using rheumatoid peripheral blood non-T cells (P
    Rheumatology International 12/1983; 4:31-37. · 2.21 Impact Factor
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    ABSTRACT: Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/46912/1/277_2005_Article_BF02044602.pdf

Publication Stats

324 Citations
61.14 Total Impact Points

Institutions

  • 1995
    • Johannes Gutenberg-Universität Mainz
      Mayence, Rheinland-Pfalz, Germany
  • 1994–1995
    • Goethe-Universität Frankfurt am Main
      • Zentrum der Inneren Medizin
      Frankfurt am Main, Hesse, Germany
  • 1988–1989
    • Friedrich-Alexander Universität Erlangen-Nürnberg
      • Rheumatology and Immunology Clinic
      Erlangen, Bavaria, Germany