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Garvey G, Towney P, McPhee JR, Little M, Kerridge IH. Is there an Aboriginal bioethic? JOURNAL OF MEDICAL ETHICS 2004; 30:570-575. [PMID: 15574447 PMCID: PMC1733993 DOI: 10.1136/jme.2002.001529] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
It is well recognised that medicine manifests social and cultural values and that the institution of healthcare cannot be structurally disengaged from the sociopolitical processes that create such values. As with many other indigenous peoples, Aboriginal Australians have a lower heath status than the rest of the community and frequently experience the effects of prejudice and racism in many aspects of their lives. In this paper the authors highlight values and ethical convictions that may be held by Aboriginal peoples in order to explore how health practitioners can engage Aboriginal patients in a manner that is more appropriate. In doing so the authors consider how the ethics, values, and beliefs of the dominant white Australian culture have framed the treatment and delivery of services that Aboriginal people receive, and whether sufficient effort has been made to understand or acknowledge the different ethical predispositions that form the traditions and identity of Aboriginal Australia(ns).
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Vajjhala PR, Macmillan E, Gonda T, Little M. The Wilms' tumour suppressor protein, WT1, undergoes CRM1-independent nucleocytoplasmic shuttling. FEBS Lett 2003; 554:143-8. [PMID: 14596929 DOI: 10.1016/s0014-5793(03)01144-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Wilms' tumour suppressor gene (WT1) encodes a zinc finger-containing nuclear protein essential for kidney and urogenital development. Initially considered a transcription factor, there is mounting evidence that WT1 has a role in post-transcriptional processing. Using the interspecies heterokaryon assay, we have demonstrated that WT1 can undergo nucleocytoplasmic shuttling. We have also mapped the region responsible for nuclear export to residues 182-324. Our data add further complexity to the role of WT1 in transcriptional and post-transcriptional regulation.
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Jacobin MJ, Robert R, Pouns O, Laroche-Traineau J, Nurden A, Peter K, Little M, Clofent-Sanchez G. Improving selection of αIIbβ3-binding phage antibodies with increased reactivity derived from immunized donors. Clin Immunol 2003; 108:199-210. [PMID: 14499243 DOI: 10.1016/s1521-6616(03)00143-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Although many studies of the immune response in polytransfused Glanzmann thrombasthenia (GT) patients and in autoimmune thrombocytopenic purpura (AITP) have demonstrated the frequent development of Abs directed against the alphaIIbbeta3 integrin, little is known about the induced anti-alphaIIbbeta3 autoantibodies at the molecular level. Phage display is a powerful technology for selecting and engineering mAbs expressed on the surface of filamentous bacteriophage. Combinatorial libraries of single-chain IgG were constructed from splenocytes from two patients with AITP and one patient with GT. In a previous study, activated platelets or alphaIIbbeta3-expressing CHO cells selection was performed to isolate human IgG anti-alphaIIbbeta3 binding fragments using combinatorial libraries created from the B cells of a GT and an AITP patient. However, we have experienced practical problems such as enrichment of truncated antibodies during selection. We decided to test prolonged treatments with elution agents after screening on the purified form of the alphaIIbbeta3 integrin activated with the RGD peptide. We obtained a higher percentage of clones with full-size antibody fragments as well as an enrichment of more specific alphaIIbbeta3-binding phage-Abs. Some of them, recognizing the activated form of the integrin, would be interesting to further study as potential diagnostic or therapeutic agents in acute coronary syndromes. Sequencing of selected phage-Abs revealed that they used different VH and VL genes with, for the majority of them, a high level of extensive hypermutations in the complementarity determining regions, indicating the diversity of the antigen-driven immune response that occurred in GT and AITP patients.
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Schwarz M, Roettgen P, Little M, Ylaenne J, Bode C, Peter KH. Human, conformation-specific, anti-GPIIb/IIIa (alphaIIbbeta 3) single-chain antibodies generated by differential phage-display: a new generation of platelet inhibitors specific for the activated GPIIb/IIIa receptor? J Thromb Haemost 2003. [DOI: 10.1111/j.1538-7836.2003.tb04329.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Little M, Murray L, Armstrong J, Dawson AH, Whyte IM, Isbister GK, Dowsett R, Graudins A, Daly F, Braitberg G. Clinical toxicology: 'bones' of contention. CRIT CARE RESUSC 2003; 5:71-3; author reply 73-6. [PMID: 16573460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
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Little M. The Ethics of Medical Research on Humans. J R Soc Med 2002. [DOI: 10.1258/jrsm.95.5.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Kobak R, Little M, Race E, Acosta MC. Attachment disruptions in seriously emotionally disturbed children: implications for treatment. Attach Hum Dev 2001; 3:243-58. [PMID: 11885812 DOI: 10.1080/14616730110096861] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this paper, we consider the effect of attachment disruptions on severe adjustment problems in school-age boys. Three groups of 9-11-year-old boys were sampled based on their degree of risk for adjustment difficulties: (1) boys in regular classrooms, (2) boys in regular classrooms who are at risk due to poverty, and (3) boys who have been placed in special education classrooms as a result of serious emotional disturbance (SED). Attachment disruptions were categorized according to the severity of major separations from the biological mother. SED children experienced significantly more severe disruptions of their relationships with their biological mothers and fathers than either the high-risk or comparison boys. Teachers' ratings indicated that both the high-risk and SED boys experienced more externalizing symptoms than comparison boys in regular classrooms. However, SED children were most clearly discriminated from their high-risk and comparison counterparts by higher levels of dissociative symptoms. Regression analyses indicated that children who had experienced maternal attachment disruptions were more likely to show dissociative symptomatology in the classroom setting and were more likely to develop dependent relationships with their teachers after risk group status, child age and family structure were controlled. Implications of these findings for the treatment of SED children are discussed.
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Isbister GK, Little M, Seymour J. Jellyfish stings. VETERINARY AND HUMAN TOXICOLOGY 2001; 43:373-4. [PMID: 11758000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Jordens CF, Little M, Paul K, Sayers EJ. Life disruption and generic complexity: a social linguistic analysis of narratives of cancer illness. Soc Sci Med 2001; 53:1227-36. [PMID: 11556612 DOI: 10.1016/s0277-9536(00)00422-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This paper draws on social linguistics to inquire into the meaning and function of complexity in illness narratives. According to social linguists, five different story-type genres occur in spoken English. These are illustrated and differentiated using examples drawn from 10 interviews with people who have undergone colectomy for colorectal cancer. In order to test a hypothesis that complexity in illness narratives is related to life disruption, the 10 accounts were ranked in terms of their generic complexity. Measures of life disruption were based on rankings furnished independently by two readers from different disciplines who were blind to the hypothesis being tested. These two rankings showed a high level of agreement (r(s) = 0.85, p<0.01). When the two life disruption rankings and the generic complexity ranking were compared, a high degree of concordance between the three rankings was observed (W = 0.91, p<0.01). No evidence was found of associations between generic complexity and gender, interviewer, surgical outcome in terms of stoma (p>0.05), age (p>0.7) nor time since diagnosis (p>0.1). We conclude that in this study, generic complexity was strongly and significantly related to life disruption. To explain the function of complexity in interaction, we characterise the illness narrative as a genre in its own right, and argue that illness narratives need to be considered both in terms of the work they do both on the listener and for the narrator. In the former case, complexity opens up a discursive space for the dynamic positioning of the interlocutor. In the latter case, we propose that complexity reflects the degree to which the process of re-ordering life by assigning meaning is occurring as the interaction unfolds. In both cases, complex narratives can thus be understood as "hard working" narratives.
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Bridges J, Hanson R, Little M, Flannigan AC, Fairley M, Haywood L. Ethical relationships in paediatric emergency medicine: moving beyond the dyad. EMERGENCY MEDICINE (FREMANTLE, W.A.) 2001; 13:344-50. [PMID: 11554867 DOI: 10.1046/j.1035-6851.2001.00238.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most areas of health-services research concentrate on a dyadic relationship between doctor and patient. In paediatric emergency medicine it may be necessary to focus on a more complicated relationship because the parents of the child play an important role in the delivery of medical services. This paper discusses the ethical principles in paediatric emergency medicine from the perspective of five disciplines: health economics, paediatrics, medical ethics, law and mental health. The general consensus is that the traditional dyadic model is inadequate and that a more complicated relationship is needed for the paediatric emergency setting, such as triadic, multiple-dyadic or polyadic. Such models allow the inclusion of the parents and possibly other family members, medical providers and community members. If the paediatric setting is considered in such a framework, it may be possible to deliver a more socially beneficial medical service.
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Schmitt WE, Stassar MJ, Schmitt W, Little M, Cochlovius B. In vitro induction of a bladder cancer-specific T-cell response by mRNA-transfected dendritic cells. J Cancer Res Clin Oncol 2001; 127:203-6. [PMID: 11260867 DOI: 10.1007/s004320000201] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To design a tumor-specific immunotherapeutic strategy for treating tumors for which no specific antigens are described (such as bladder urothelial carcinoma), we attempted to activate tumor-specific T-cells by dendritic cells transfected with tumor-derived mRNA. METHODS Dendritic cells were generated from a patient's peripheral blood and loaded with mRNA derived from the urothelial carcinoma tissue of the same patient. Autologous T-cells were incubated twice on these dendritic cells and tested for their ability to lyse tumor cells. RESULTS Dendritic cells transfected with tumor-derived mRNA were able to activate T-cells that recognized autologous tumor cells. Cytotoxicity was around 26% for an effector:target ratio of 50:1. Tumor-infiltrating lymphocytes did not kill the autologous tumor cells in vitro, but after a single stimulation with the transfected dendritic cells, they induced tumor cell lysis of 35.7% at an effector:target ratio of 50:1. CONCLUSIONS These results indicate that dendritic cells transfected with tumor mRNA containing messages for one or more tumor antigens could serve for the ex vivo activation of effector T-cells or directly as vaccines for a wide range of human neoplasias.
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Little M, Mulcahy RF, Wenck DJ. Life-threatening cardiac failure in a healthy young female with Irukandji syndrome. Anaesth Intensive Care 2001; 29:178-80. [PMID: 11314837 DOI: 10.1177/0310057x0102900212] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a case of a previously well 24-year-old female patient who developed severe and life-threatening Irukandji syndrome that required ventilation and inotropic support. This case provides further evidence that there are jellyfish other than the Irukandji jellyfish that can cause cardiac decompensation, and there is a suggestion that application of a pressure immobilization bandage may worsen the envenomation. We include our recommended treatment for the Irukandji syndrome.
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Choi I, De Ines C, Kürschner T, Cochlovius B, Sörensen V, Olafsen T, Sandlie I, Little M. Recombinant chimeric OKT3 scFv IgM antibodies mediate immune suppression while reducing T cell activation in vitro. Eur J Immunol 2001; 31:94-106. [PMID: 11169443 DOI: 10.1002/1521-4141(200101)31:1<94::aid-immu94>3.0.co;2-j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OKT3, a mouse anti-human CD3 monoclonal antibody (mAb), is a potent immunosuppressive agent used in clinical transplantation to treat allograft rejection. Two major drawbacks of this therapy are the systemic release of several cytokines due to cross-linking mediated by the mAb between T cells and FcgammaR-bearing cells and the human anti-mouse antibody (HAMA) response. To overcome these side effects, three chimeric OKT3 single chain variable fragment (scFv) IgM antibodies, scOKT3-gamma DeltaIgM wt, scOKT3-gamma DeltaIgM C575S and scOKT3-gamma DeltaIgM VAEVD, were generated. They consist of the light and heavy variable binding domains of OKT3 mAb as well as the CH3 and CH4 domains of different human IgM variants linked with a human IgG3 hinge region to provide more flexibility and stability. Like the native IgM, scOKT3-gamma DeltaIgM antibodies are able to form polymeric structures, which lead to an increase in binding affinity and immunosuppressive potential compared with the parental OKT3 mAb. However, independently of their polymerization, all scOKT3-gamma DeltaIgM constructs do not induce any significant T cell proliferation or cytokine release (IL-2, TNF-alpha and IFN-gamma) in in vitro assays, while their CD3-modulating properties are retained. These results suggest that the use of scOKT3-gamma DeltaIgM antibodies may offer significant advantages over the OKT3 mAb in improving clinical immunosuppressive treatment.
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Pereira PL, Carrette T, Cullen P, Mulcahy RF, Little M, Seymour J. Pressure immobilisation bandages in first-aid treatment of jellyfish envenomation: current recommendations reconsidered. Med J Aust 2000; 173:650-2. [PMID: 11379519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To evaluate whether applying pressure equivalent to that of pressure immobilisation bandages (PIB) causes release of additional venom from discharged jellyfish nematocysts. DESIGN In-vitro experiment--the venom beads released from electrically activated Chiropsalmus sp. nematocysts were viewed under direct microscopy before and after applying 40 mmHg pressure (replicating the pressure of PIB); and saline washings of discharged nematocysts before and after applying pressure were tested for toxicity (time to ventricular standstill after injecting into live prawns). RESULTS Applying 40 mmHg pressure caused the venom beads to visibly increase in size, consistent with pressure expressing further venom from the discharged nematocysts. First washings of the nematocyst shafts before compression produced ventricular standstill in prawns within 60 seconds (n=3); second washings did not produce standstill during 540 seconds of observation (n=3); and washings after applying 40 mmHg pressure showed a return of toxicity, with ventricular standstill in all prawns within 180 seconds (n=3). CONCLUSION Discharged nematocysts are by no means empty and harmless. Applying pressure results in further release of nematocyst venom. The currently recommended practice of applying PIB in the initial treatment of patients stung by a jellyfish may exacerbate the envenomation, and thus should not be recommended.
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Lai Q, Shea CH, Little M. Effects of modeled auditory information on a sequential timing task. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2000; 71:349-356. [PMID: 11125533 DOI: 10.1080/02701367.2000.10608918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The purposes of the present experiment were to determine (a) whether an auditory model enhanced relative or absolute timing, (b) the extent to which the reduced frequency presentation of the auditory model resulted in enhanced retention, and (c) the degree to which executing the timing sequence was independent of the role of the effectors in carrying out the movement sequence. Participants (N = 45) were asked to alternately press two keys on a computer keyboard in an attempt to match the goal intervals presented on the computer monitor. Groups differed in terms of the frequency with which an auditory model (100, 50, or 0%) was presented. The results indicated that the auditory model (100% or 50% groups) enhanced relative timing performance and learning but not the learning of absolute timing. In addition, the 50% group did not appear to become dependent on the auditory model. However, significant decrements in performance were seen for the 100% group when the model was withdrawn. Last, participants were able to execute the timing sequences equally well when they reversed the hand used to execute the timing sequence. This was interpreted as strong evidence for the effector independence (Schmidt, 1975, 1988) and modularity of the timing sequence (Keele, Davidson, & Hayes, 1998).
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Abstract
This paper examines conflict of interest as it may arise in the activities of research advisory committees and ethical review committees. It distinguishes between vested interests and true conflict of interest. It also examines the ways in which stakeholdings differ from vested interests and conflicting interests differ from conflicts of interest. It explores the overlapping terrain of corruption and conflict of interest. The paper further examines the ways in which scientists, communities and the subjects of medical research all have legitimate stakeholdings in medical research. Each group thus has differently vested interests in the outcomes of the research. The vested interests of medical scientists are particularly complex because scientists have moral commitments to the welfare of patients that may compete with professional and personal interests in the outcome of research performed on those patients as research subjects. The more these interests diverge, the more opportunity will arise for conflict of interest. These observations have implications for the constitution of research advisory and ethical review committees, and the ways in which their discussions are conducted. Some practical help with protocols of discussion can be gained from philosophical and management writings.
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de Inés C, Cochlovius B, Schmidt S, Little M. A cell surface-displayed anti-c-myc single-chain antibody: new perspectives for the genetic improvement of cellular tumor vaccines. Cancer Gene Ther 2000; 7:1257-62. [PMID: 11023198 DOI: 10.1038/sj.cgt.7700230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have shown recently that cell surface-bound, single-chain Fv antibodies (scFv) are a powerful tool for the improvement of cellular tumor vaccines. To simplify this approach and to develop a general tool for the generation and improvement of cellular tumor vaccines, we chose an scFv against a peptide from the human proto-oncogene c-myc that could anchor any c-myc-tagged protein to the cell surface. The retroviral vector p50-Mx-neo (pMESV) was used to express scFv on the surface of the human melanoma line SkMel63. The cell-bound anti-c-myc scFv bound specifically to a soluble purified anti-CD28 scFv carrying a c-myc peptide-tag at its C terminus. Proof of principle was determined by incubating human peripheral blood lymphocytes with a mixture of (a) anti-c-myc-transfected SkMel63 cells binding the anti-CD28 scFv and (b) SkMel63 cells transfected with an anti-CD3 scFv. A clear synergistic effect on T-cell activation was observed that was comparable with that obtained in previous studies using SkMel63 cells transfected with the gene for the anti-CD28 scFv. As the cell surface-displayed anti-c-myc scFv can bind any c-myc-tagged protein of interest, this technique facilitates the genetic engineering of cellular vaccines for the therapy of virtually all human neoplasias.
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Cochlovius B, Kipriyanov SM, Stassar MJ, Schuhmacher J, Benner A, Moldenhauer G, Little M. Cure of Burkitt's lymphoma in severe combined immunodeficiency mice by T cells, tetravalent CD3 x CD19 tandem diabody, and CD28 costimulation. Cancer Res 2000; 60:4336-41. [PMID: 10969772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
To increase the valency, stability, and therapeutic potential of bispecific antibodies, we have constructed a tetravalent tandem diabody (Tandab) that is specific to both human CD3 (T-cell antigen) and CD19 (B-cell marker; S. M. Kipriyanov et al., J. Mol. Biol., 293: 41-56, 1999). It was generated by the functional dimerization of a single chain molecule that contained four antibody variable domains (V(H) and V(L)) in an orientation that prevented intramolecular pairing. Compared with a previously constructed heterodimeric CD3 x CD19 diabody, the Tandab exhibited a higher apparent affinity to both CD3+ and CD19+ cells and longer blood retention when injected into mice. Biodistribution studies in mice bearing Burkitt's lymphoma xenografts demonstrated specific accumulation of the radioiodinated Tandab in a tumor site with tumor-to-blood ratios of 1.5, 8.1, and 13.3 at 3, 18, and 24 h, respectively. Treatment of severe combined immunodeficiency mice bearing established Burkitt's lymphoma (5 mm in diameter) with human peripheral blood lymphocytes, Tandab, and anti-CD28 MAbs resulted in the complete elimination of tumors in all of the animals within 10 days. In contrast, mice receiving human peripheral blood lymphocytes in combination with either the diabody alone or the diabody plus anti-CD28 MAbs showed only partial tumor regression. These data demonstrate that the CD3 x CD19 Tandab may be a promising tool for the immunotherapy of human B-cell leukemias and lymphomas.
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Little M, Kipriyanov SM, Le Gall F, Moldenhauer G. Of mice and men: hybridoma and recombinant antibodies. IMMUNOLOGY TODAY 2000; 21:364-70. [PMID: 10916138 DOI: 10.1016/s0167-5699(00)01668-6] [Citation(s) in RCA: 290] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Thousands of mouse monoclonal antibodies have been produced from hybridomas over the past 25 years. The same technique can now be used to clone human antibodies from transgenic mice. Full-length antibodies and recombinant fragments engineered for various diagnostic and therapeutic applications can be obtained in reasonably large amounts after expression in mammalian cells, milk and plants.
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Cochlovius B, Kipriyanov SM, Stassar MJ, Christ O, Schuhmacher J, Strauss G, Moldenhauer G, Little M. Treatment of human B cell lymphoma xenografts with a CD3 x CD19 diabody and T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:888-95. [PMID: 10878363 DOI: 10.4049/jimmunol.165.2.888] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The use of anti-CD3 x antitumor bispecific Abs is an attractive and highly specific approach in cancer therapy. Recombinant Ab technology now provides powerful tools to enhance the potency of such immunotherapeutic constructs. We designed a heterodimeric diabody specific for human CD19 on B cells and CD3epsilon chain of the TCR complex. After production in Escherichia coli and purification, we analyzed its affinity, stability, and pharmacokinetics, and tested its capacity to stimulate T cell proliferation and mediate in vitro lysis of CD19+ tumor cells. The effect of the diabody on tumor growth was investigated in an in vivo model using immunodeficient mice bearing a human B cell lymphoma. The CD3 x CD19 diabody specifically interacted with both CD3- and CD19-positive cells, was able to stimulate T cell proliferation in the presence of tumor cells, and induced the lysis of CD19+ cells in the presence of activated human PBL. The lytic potential of the diabody was enhanced in the presence of an anti-CD28 mAb. In vivo experiments indicated a higher stability and longer blood retention of diabodies compared with single chain Fv fragments. Treatment of immunodeficient mice bearing B lymphoma xenografts with the diabody and preactivated human PBL efficiently inhibited tumor growth. The survival time was further prolonged by including the anti-CD28 mAb. The CD3 x CD19 diabody is a powerful tool that should facilitate the immunotherapy of minimal residual disease in patients with B cell leukemias and malignant lymphomas.
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MESH Headings
- Animals
- Antibodies, Bispecific/genetics
- Antibodies, Bispecific/isolation & purification
- Antibodies, Bispecific/pharmacokinetics
- Antibodies, Bispecific/pharmacology
- Antigens, CD19/genetics
- Antigens, CD19/immunology
- Antineoplastic Agents/isolation & purification
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/pharmacology
- Binding Sites, Antibody
- Gene Expression/immunology
- Humans
- Jurkat Cells
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/therapy
- Male
- Mice
- Mice, Knockout
- Neoplasm Transplantation
- Receptor-CD3 Complex, Antigen, T-Cell/genetics
- Receptor-CD3 Complex, Antigen, T-Cell/immunology
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/isolation & purification
- Recombinant Proteins/pharmacokinetics
- Recombinant Proteins/pharmacology
- T-Lymphocytes/transplantation
- Transplantation, Heterologous/immunology
- Tumor Cells, Cultured
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