bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation and testing of a highly specific anti‐serum directed against porcine endogenous retrovirus nucleocapsid
Authors: Krach Ulrich , Fischer Nicole , Czauderna Frank , Kurth Reinhard , Tönjes Ralf R.
Published: March 2003

Abstract: Advances in xenotransplantation offer chances to alleviate the shortage of human donor organs. The discovery that pig endogenous retroviruses (PERV) can infect human cells in vitro has stimulated the discussion on infectious risk in xenotransplantation. A molecular and immunologic monitoring of xenograft recipients and of donor animals for putative infection with PERV and other microorganisms is inevitable. In this report, we describe the generation and testing of a highly specific anti‐serum directed against the PERV nucleocapsid protein. The Gag amino acid (aa) sequence of PERV class B was used to define immunogenic domains by computer analysis. A peptide corresponding to the C‐terminal 19 aa of the 10 kDa (p10) nucleocapsid (NC) portion of the Gag polyprotein was used to immunize rabbits. The generated serum was tested using recombinant PERV Gag protein expressed in insect cells, purified PERV virus particles and human 293 cells transfected or infected with PERV, respectively. Test methods included Western blotting, indirect immunofluorescence, immunoperoxidase assay and ELISA. The PERV anti‐serum provides a tool that is instrumental for detection of a potential agent of zoonosis. It can be used for screening of donor animals and xenograft recipients in the course of xenotransplantation procedures.
Pre‐transplant blood transfusion induces tolerance to hamster cardiac xenografts in athymic nude rats
Authors: Vriens Patrick W. , Stoot Jan H. , Hoyt Grant , Scheringa Marcel , Bouwman Eelco , Robbins Robert C.
Published: March 2003

Abstract: The effects of pre‐transplant blood transfusion vary from induction of antibodies and accelerated graft rejection, to prolonged survival and even tolerance. The beneficial ‘transfusion effect’ in allotransplantation is believed to be merely T‐cell mediated. In xenotransplantation, T‐cell independent mechanisms form a major hurdle. In this study we investigated the effects of pre‐transplant hamster blood transfusion on the survival of hamster cardiac xenografts in T‐cell deficient athymic nude rats. Nude rats rejected xenografts after 3.8 ± 0.5 d (n = 8), and immunocompetent Lewis rats after 4.0 ± 0.5 d (n = 8), following a similar IgM response (P = NS). Hamster blood transfusion 3 d before transplantation in nude rats led to an IgM response and long‐term xenograft survival in 17/20. Timing was of importance: blood transfusion 7 d before transplantation resulted in 45% long‐term xenograft survival (n = 20). Injection of purified hamster erythrocytes, leukocytes or minced heart also led to survival of xenografts for > 100 d in nude rats, but not in all cases. Second xenografts transplanted to long‐term survivors did not provoke an IigM response, and were accepted for > 100 d (n = 4). Transfer of serum from long‐term survivors to untreated nude rats resulted in survival of xenografts for > 100 d (n = 4). In Lewis rats pre‐transplant blood transfusion induced hyperacute rejection of xenografts after 158 ± 128 min (n = 8, P < 0.01). We conclude that pre‐transplant hamster blood transfusion can induce long‐term survival of hamster cardiac xenografts in T‐cell deficient athymic nude rats. This blood transfusion effect is mediated by humoral factors and can be transferred by serum. Elucidation of underlying mechanisms might provide some insight into xenotransplantation nonresponsiveness of T‐cell independent immunefactors.
Human thrombin and FXa mediate porcine endothelial cell activation; modulation by expression of TFPI‐CD4 and hirudin‐CD4 fusion proteins
Authors: Chen Daxin , Riesbeck Kristian , McVey John H. , Kemball‐Cook Geoff , Tuddenham Edward G. D. , Lechler Robert I. , Dorling Anthony
Published: March 2003

Abstract: Aside from their critical role in thrombosis, activated coagulation factors also have inflammatory properties and these may be important during delayed xenograft rejection (DXR). This study assessed whether porcine EC could be activated by factor Xa (FXa) and thrombin (FIIa) and whether expression of tissue factor pathway inhibitor (TFPI)‐CD4 and hirudin‐CD4 fusion proteins could prevent such activation. Incubation of porcine EC with human FXa and FIIa induced cell surface expression of E‐selectin, VCAM and tissue factor (TF) in a time‐dependent and concentration‐dependent manner. In contrast, porcine EC transfected with a human TFPI‐CD4 fusion protein were selectively resistant to these pro‐inflammatory effects of FXa but not FIIa. Likewise, the transfectants expressing the hirudin‐CD4 fusion protein were selectively resistant to the pro‐inflammatory effects of FIIa but not those of FXa. When combined, the FXa and FIIa had an additive effect on the activation of control EC. In contrast, coexpression of both hirudin‐CD4 and TFPI‐CD4 fusion proteins completely inhibited the upregulation of VCAM with the FXa/FIIa mix. These results indicate that expression of novel anticoagulant fusion proteins on the surface of porcine EC can protect against EC activation induced by human coagulation factors FXa and FIIa. In vivo, we anticipate that expression of these fusion proteins on the endothelium of transplanted xenografts, besides preventing intravascular thrombosis, will also protect against EC activation induced by trace amounts of FIIa and FXa, thereby further protecting the grafts from DXR.
Isolation of mouse‐to‐rat cardiac xenograft‐infiltrating cells by ex vivo propagation
Authors: Lorant Tomas , Engstrand Mats , Tufveson Gunnar , Johnsson Cecilia
Published: March 2003

Ex vivo propagation of graft infiltrating lymphocytes has become a useful method for the examination of the cellular response after allogeneic transplantation. The aim of the present study was to investigate if this method can be used also for isolation of xenograft infiltrating cells, and, if so, to further characterize these cells.

The concordant mouse‐to‐rat heart transplantation model was used for the experiments. Recipient rats were treated either with 15‐deoxyspergualin (DSG) or with a combination of DSG and cyclosporine A (CyA) or left untreated. Transplants were removed beating on day 2 (untreated) or day 8 (DSG and CyA + DSG) and biopsies were incubated in culture medium for 48 h, resulting in propagation of cells from the biopsies into culture medium. The propagated cells were counted and phenotyped using flow cytometry. In parallel, the transplants were examined morphologically and immunohistochemically.

Infiltrating cells could be isolated from all grafts in all groups. The number of propagated T lymphocytes during cellular rejection (DSG‐treatment) was about 3.5 times higher than during `non‐rejection' (CyA + DSG) and six times higher than during acute vascular rejection (untreated). These findings were supported both by the morphological and the immunohistochemical findings.

In conclusion, we have shown that graft infiltrating lymphocytes can be isolated from xenogeneic heart transplants by incubation of biopsies for 48 h, resulting in spontaneous propagation of immune cells into culture medium. Propagated cells could be further characterized by flow cytometry. Thus, the technique presented here can be used as a tool for studies of xenogeneic cellular rejection.
Extracorporeal liver perfusion as hepatic assist in acute liver failure: a review of world experience
Authors: Pascher Andreas , Sauer Igor M. , Hammer Claus , Gerlach Joerg C. , Neuhaus Peter
Published: March 2003

Background: There are almost no prospective, controlled and randomized clinical trials comparing different approaches towards hepatic assist. In order to create a basis for comparing the value of the existing different hepatic assist methods this article offers a systematic review of the world experience with allogeneic or xenogeneic extracorporeal liver perfusion (ECLP).

Methods: An Internet‐assisted search was conducted in the international literature published from 1964 to 2000. Only articles with a clear description of methodology and outcome of patients were included. For multivariate analysis of variance the general linear method (GLM) procedure was used. Differences within the groups were analyzed by chi‐square test. Data of 198 patients were included into the statistical analysis for systematic review.

Results: The long‐term survival rate (SVR) of these patients was 26%, thus not exceeding published data concerning SVR under standard intensive care. Age below 40 years (P<0.029), coma stage lower than III–IV (P<0.003), total perfusion time over 10 hours (P<0.024), hepatitis B as cause for acute liver failure (ALF) (P<0.05) as well as use of baboon and human livers (P<0.02) were identified as independent positive prognostic markers for improved survival. ECLP as bridging therapy to liver transplantation was successful in 12 of 14 patients.

Conclusion: ECLP using pig livers did not surpass the success of conventional intensive care treatment. An additional effect of transgenic expression of human regulators of complement regulation in porcine livers has not yet been proven. ECLP with human livers not suitable for liver transplantation might prove effective and practicable for temporary hepatic support. Bridging to liver transplantation by long‐term ECLP using porcine and human livers appears to have comparable efficacy as bioartificial support methods.
Exploiting virus stealth technology for xenotransplantation: reduced human T cell responses to porcine cells expressing herpes simplex virus ICP47
Authors: Crew Mark D. , Phanavanh Bounleut
Published: March 2003

Crew MD, Phanavanh B. Exploiting virus stealth technology for xenotransplantation: reduced human T cell responses to porcine cells expressing herpes simplex virus ICP47. Xenotransplantation 2003; 10: 50–59. © Blackwell Munksgaard, 2003

Direct recognition of porcine major histocompatibility complex (MHC) proteins by human T cells is well documented. Eliminating donor (porcine) MHC proteins may therefore be beneficial in pig‐to‐human xenotransplants. To this end, we have attempted to exploit viral stealth mechanisms to eliminate pig MHC class I cell‐surface expression. PK(15) (pig kidney) cells stably transfected with the herpes simplex virus (HSV) ICP47 gene [PK(15)‐ICP47 cells] exhibited a dramatic reduction of MHC class I cell‐surface expression when compared with untransfected PK(15) cells. To test the effect of down‐regulation of porcine MHC class I on human cellular immune responses, a human CD8+ enriched T cell line (anti‐PK15 T cells) with reactivity towards PK(15) cells was derived by repeated stimulation of human T cells with PK(15) cells stably transfected with the costimulatory molecule B7.1 [PK(15)‐B7.1 cells]. Anti‐PK15 T cells efficiently lyzed PK(15) cells but not PK(15)‐ICP47 (class I negative) cells. Consistent with effector function, anti‐PK15 T cells showed a robust proliferative response to PK(15)‐B7.1 cells but did not proliferate at all to PK(15)‐B7.1 cells which also expressed HSV ICP47. These results suggest that virus stealth technology can be exploited for xenotransplantation.
Why are scanning patterns so variable? An overlooked question in the study of anti‐predator vigilance
Authors: Bednekoff Peter A. , Lima Steven L.
Published: March 2003

Anti‐predator vigilance describes how animals scan their environments for predators. For mathematical simplicity, theories of anti‐predator vigilance have generally assumed that animals initiate scans with a constant probability for each unit of time spent feeding. Initiating scans in such a fashion would produce a wide distribution of intervals between scans. Because so much variation was assumed by theory, observations of variation have received little consideration. We show that the original theories of vigilance contain a conceptual discrepancy between the assumed predator and anti‐predator tactics. Modified versions of the theory allow variation only under restrictive circumstances that seem unlikely to apply in nature. Plausible reasons for the observed variation in interscan interval are that theories of vigilance assume the wrong predator tactics or the wrong details of predator detection. These possibilities lead to testable predictions about how distributions of interscan intervals should change under different threat and detection conditions.
Diverge or merge? The effect of sympatric occurrence on the territorial vocalizations of the vinaceous dove Streptopelia vinacea and the ring‐necked dove S. capicola
Authors: De Kort Selvino R. , Den Hartog Paula M. , Ten Cate Carel
Published: March 2003

Sympatric occurrence of two closely related species is expected to lead to diverging or converging shifts in signal characteristics of one or both species. We examined signal characteristics in the vinaceous dove Streptopelia vinacea and the ring‐necked dove S. capicola, two sister species that are mainly allopatric but occur in sympatry in northwestern Uganda. Vocal characteristics of the birds in sympatry were compared with those of an adjacent and a distant allopatric population of each species. The sympatric population showed intermediate values between the allopatric populations from Uganda. However, within each species there is little geographic variation between distant allopatric populations. Since vocal differences between dove species have a genetic base, the convergence in vocal characteristics is most likely explained by hybridization. Probably, the two species came into secondary contact relatively recently. Climatic changes during the last several thousand years and recent habitat changes caused by the growing human population, may have allowed Streptopelia capicola to extend its range in the northern direction.
Daily patterns of body mass gain in four species of small wintering birds
Authors: Lilliendahl Kristjan
Published: March 2003

Theoretically, the trajectories describing the daily accumulation of body reserves are expected to differ between bird species in relation to whether or not they hoard food. To carry reserves on the body may be costly and hoarding species can be expected to hoard food early in the day when light and retrieve it in the afternoon, with a concomitant rapid increase in body mass. Also, the increased food predictability resulting from being able to consume hoarded food late in the day should lead to a relatively faster gain in body reserves in the afternoon in hoarding species compared to non‐hoarders. Non‐hoarders may have to hedge against possible afternoon losses of foraging opportunities by accumulating more reserves early in the day.  In this study the daily patterns of body mass gain in four small bird species resident during winter in Scandinavia are described. Individually known birds were trained to come to a permanent feeder and their body masses were recorded every hour throughout the day with a remote‐controlled balance. The hoarding willow tit Parus montanus, marsh tit P. palustris and European nuthatch Sitta europaea all displayed the most rapid gain in body mass in the early hours of the day. After the initial burst in the morning, reserves were accumulated at a roughly constant rate for the remainder of the day. In contrast, the non‐hoarding great tit P. major apparently gained body reserves at a more even rate. The daily pattern of body mass gain found in the hoarding species differs from prevailing theoretical predictions, whereas the pattern in the non‐hoarding great tit is in a better agreement with theory, from which this pattern has been predicted repeatedly.
Primary biliary cirrhosis: an orchestrated immune response against epithelial cells
Authors: Gershwin M. Eric , Ansari Aftab A. , Mackay Ian R. , Nakanuma Yasuni , Nishio Akiyoshi , Rowley Merrill J. , Coppel Ross L.
Published: March 2003

Summary: Primary biliary cirrhosis (PBC) is an organ‐specific autoimmune disease that predominantly affects women and is characterized by chronic progressive destruction of small intrahepatic bile ducts with portal inflammation and ultimately fibrosis. The serologic hallmark of PBC is the presence of antibodies to mitochondria, especially to the E2 component of the pyruvate dehydrogenase complex. The mechanisms by which (and if) such antibodies produce liver tissue injury are unknown. However, the presence of these antibodies has allowed detailed immunological definition of the antigenic epitopes, the nature of reactive autoantibodies and the characterization of T‐cell responses. Several mechanisms may now be proposed regarding the immune‐mediated bile duct damage in PBC, including the possible role of T‐cell‐mediated cytotoxicity and intracellular interaction between the IgA class of antimitochondrial antibodies and mitochondrial autoantigens. There are major questions which remain unanswered, including, of course, etiology, but also the reasons for female predominance, the absence of PBC in children, the relative ineffectiveness of immunosuppressive drugs, and the specific role of mitochondrial antigens. The data so far provide suggestive evidence that PBC is a mucosal disease; this thesis provides a basis for discussion of etiology via the enterohepatic circulation of toxins and/or infection.
The peculiar autoimmunity of primary biliary cirrhosis
Authors: Mackay Ian R. , Whittingham Senga , Fida Shahnaz , Myers Mark , Ikuno Nobuhiro , Gershwin M. Eric
Published: March 2003

Summary: Autoantibodies to mitochondria (AMA, anti‐M2) are a serologic hallmark of primary biliary cirrhosis (PBC). These react with three structurally and functionally related multienzymic complexes, the 2‐oxoacid dehydrogenase complexes, but chiefly with the E2 subunit of pyruvate dehydrogenase complex (PDC‐E2). Their very close (95%) and specific association with PBC underpins the autoimmune concept of pathogenesis of that disease, notwithstanding several non‐congruent features. Detailed studies, including structural analysis of epitopes, do not disclose how these autoantibodies originate. Their ubiquity in PBC has overshadowed the existence of a second set of relatively PBC‐specific autoantibodies to nuclear antigens for which reactants have been cloned and characterized. These include centromeric proteins; proteins of the nuclear pore complex; nuclear dot proteins, which include Sp‐100 and the promyelocytic leukemia antigen; and a recently identified autoantigen, SOX13. Certain of these reactants are DNA‐binding proteins with trans­criptional regulatory activity. Thus serum from individuals with the same clinical syndrome can have autoimmune reactivity to disparate mitochondrial and nuclear constituents in different cellular compartments. Antibody probing of phage displayed random peptide libraries, together with epitope scanning using overlapping sequential octameric peptides from the PDC‐E2 sequence, showed that the discontinuous motifs MH, FV(E) and SYP contributed to a predicted conformational antibody epitope in the inner lipoyl domain of PDC‐E2.
Orthodontic appliances made of organic polymer used in the metal allergic patient can withstand orthognathic surgery
Authors: Sakata M , Sa'do B , Nakata S , Morishita T , Nakasima A
Published: March 2003

We developed an orthodontic appliance completely made of organic polymer. The appliance was used for many years and proved very effective. It was used for the treatment of patients with metal allergy, and as a result, it is believed to be the best choice for treating metal allergics. In this report, we are presenting a surgical case with Class III malocclusion for a patient with metal allergy, and the concept of the appliance is briefly discussed.
Cranial base changes following coronal suturectomy in craniosynostotic rabbits
Authors: Putz DA , Smith TD , Burrows AM , Cooper GM , Dechant J , Losken HW , Siegel MI , Mooney MP
Published: March 2003

It has been suggested that surgical release of synostosed sutures may ameliorate various cranial base abnormalities in craniosynostotic patients. The present study was designed to test this hypothesis in a rabbit model with familial coronal suture synostosis (CSS). Data were collected from 56 New Zealand White rabbits: 32 unaffected controls, 11 with unoperated CSS, and 13 with CSS released by suturectomy performed at 25 days of age. Serial radiographs were taken at 25, 42 and 84 days. Linear, angular and triangular shape cranial base measurements were compared using ANOVA and tensor biometric analysis. Results revealed that at 84 days, both groups of CSS rabbits had significantly (p < 0.05) different anterior and total cranial base lengths, flatter cranial base angles, and dysmorphic anterior cranial base shapes when compared with normals. Significant (p < 0.05) differences were noted only for palatal and cranial base angles and posterior cranial base shape between CSS rabbits with and without suturectomy. However, significant (p < 0.05) changes were noted between pre‐ and post‐operative measurements in posterior and total cranial base lengths and anterior and posterior cranial base shapes in CSS rabbits with suturectomy. Results revealed that surgical release of synostosed coronal sutures through suturectomy did not normalize cranial base growth patterns in CSS rabbits. These findings may be explained by the relatively late age of surgical release or suturectomy site resynostosis with continued dysmorphic cranial base growth. Alternatively, cranial base abnormalities seen in CSS rabbits may be early primary malformations, not secondary deformations amenable to surgical modification.
Structural biology of C1: dissection of a complex molecular machinery
Authors: Arlaud Gérard J. , Gaboriaud Christine , Thielens Nicole M. , Rossi Véronique , Bersch Beate , Hernandez Jean‐François , Fontecilla‐Camps Juan C.
Published: March 2003

The classical pathway of complement is initiated by the C1 complex, a multimolecular protease comprising a recognition subunit (C1q) and two modular serine proteases (C1r and C1s) associated as a Ca2+‐dependent tetramer (C1s‐C1r‐C1r‐C1s). Early studies have allowed identification of specialized functional domains in these proteins and have led to low‐resolution models of the C1 complex. The objective of current studies is to gain deeper insights into the structure of C1, and the strategy used for this purpose mainly consists of dissecting the C1 components into modular fragments, in order to solve their three‐dimensional structure and establish the structural correlates of their function. The aim of this article is to provide an overview of the structural and functional information generated by this approach, with particular emphasis on the domains involved in the assembly, the recognition function, and the highly specific proteolytic properties of C1.

The original work cited in this review was supported in part by the Commissariat à l’Energie Atomique (CEA), the Centre National de la Recherche Scientifique, and the European Union Biotechnology programme.
The role of CD4+ T‐cell subsets in determining transplantation rejection or tolerance
Authors: Zelenika Diana , Adams Elizabeth , Humm Susan , Lin Chun‐Yen , Waldmann Herman , Cobbold Stephen P.
Published: March 2003

Summary: Peripheral tolerance to allogeneic organ grafts can be induced in rodents by treating with non‐depleting CD4 and CD8 monoclonal antibodies. This tolerance is maintained by CD4+ T cells with a potent capacity to induce tolerance in further cohorts of T cells (i.e. infectious tolerance). We have cloned CD4+ T‐cell subsets against the male transplantation antigen in vitro and find, in contrast to Th1 or Th2 clones that elicit rejection, that there is a distinct population of CD4+ T cells that suppress rejection by adoptive transfer (here called Treg). In order to identify molecular markers associated with tolerance and gain insights into the mechanisms of action of Treg cells, we carried out serial analysis of gene expression. We identified genes overexpressed in Treg compared to Th1 and Th2 cultures and found that some of these correlated in vivo with CD4‐induced transplantation tolerance rather than rejection. The genes overexpressed in Treg cultures and within tolerated skin grafts were primarily expressed by mast cells (e.g. tryptophan hydroxylase and FcεR1α), suggesting that regulatory cell activity and this form of tolerance may be associated with a localised but non‐destructive form of Th2‐like activation and a recruitment of mast cells.
Species‐specific evolution of MHC class I genes in the higher primates
Authors: Adams Erin J. , Parham Peter
Published: March 2003

Summary: Humans express three highly polymorphic ‘classical’ (HLA‐A,B and C) and three conserved ‘non‐classical’ (HLA‐E, F and G) MHC class I genes. Their comparison with the MHC class I genes of apes and monkeys reveals the differential extent to which MHC class I genes have been preserved during primate evolution. African apes have orthologues of all six human genes, and although allelic lineages of the A and C loci are shared, these species share none of the human alleles. In Asian apes, several MHC class I genes show significant differences from the human genes, a trend which continues with the Old World monkeys, and even more so in the New World monkeys, where E and F are the only human gene orthologues. The C locus is confined to humans and apes. Multiple A‐related and B‐related loci have been identified in apes and Old World monkeys showing that duplication of these loci has been a common event during primate evolution. Certain of the daughter loci exhibit low polymorphism, suggesting they have adopted a non‐classical function. The differing rates at which MHC class I genes have evolved during primate evolution likely reflects their differing functions in the immune response.
Preclinical evaluation of tolerance induction protocols and islet transplantation in non‐human primates
Authors: Montgomery Sean P. , Hale Douglas A. , Hirshberg Boaz , Harlan David M. , Kirk Allan D.
Published: March 2003

Summary: Non‐human primate studies of tolerance induction strategies in solid organ transplantation represent a critical bridge between studies in rodents and humans. Our work demonstrates that strategies involving the blockade of co‐stimulatory molecules, especially the CD40–CD154 pathway, have great potential for clinical adaptation. While the combination of anti‐CD154 antibody with blockade of the CD28 pathway reduced donor antibody production, graft survival was not significantly improved over that achieved with anti‐CD154 antibody alone. Moreover, although long courses of steroids seem to interfere with this approach, it may be possible to combine blockade of the CD40–CD154 pathway with other conventional immunosuppressants without sacrificing efficacy. This is a key issue for reducing the risk associated with eventual clinical trials. Work in the non‐human primate islet transplant model demonstrates that viable islets can be recovered, isolated and infused in a reliable fashion. It also confirms the efficacy of a steroid sparing approach to immunosuppression for islet transplantation. These data have been expanded to the kidney allograft model, setting the stage for kidney islet transplantation studies. Overall, tolerance induction and islet transplant studies in non‐human primates permit the preclinical screening of promising immunomodulatory approaches developed in rodents and reduce the inherent uncertainties associated with adapting new regimens to the clinic.
Migration of naive, effector and memory T cells: implications for the regulation of immune responses
Authors: Westermann Jürgen , Ehlers Eva‐Maria , Exton Michael S. , Kaiser Marcus , Bode Ulrike
Published: March 2003

Summary: T cells play an important role in protective immune responses and in the pathogenesis of many diseases. Understanding the mechanisms regulating their distribution in vivo may therefore be of therapeutic value. Reviewing studies that have followed the migration of labelled naive, effector and memory T cells in healthy animals reveals that all T‐cell subsets enter all organs investigated. Within the tissue, two principally different migration patterns can be identified. First, naive and memory T cells accumulate in lymphoid organs for about 48 h after injection, as the time needed for migration through lymphoid organs is longer than through non‐lymphoid organs. During this time, surface molecule expression is temporarily modified. These changes are reversed before leaving the lymphoid organs and entering the blood to start a new cycle of migration. Second, effector T cells are evenly distributed throughout the body, and most die in the tissues within 24 h. However, depending on the presence of cytokines, some are able to survive and to proliferate, and thereby accumulate in defined microenvironments of the body. Analysing the principles regulating T‐cell migration and survival within the tissue may lead to the development of new options for the treatment of disease.
Genetic analysis of collagen‐induced arthritis in rats: a polygenic model for rheumatoid arthritis predicts a common framework of cross‐species inflammatory/autoimmune disease loci
Authors: Griffiths Marie M. , Remmers Elaine F.
Published: March 2003

Summary: Collagen‐induced arthritis (CIA) is a useful model for dissecting the genetic patterns underlying susceptibility to rheumatoid arthritis (RA) and related chronic/inflammatory autoimmune diseases. CIA exhibits three phenotypes characteristic of autoimmune disease pathogenesis: abnormal levels of immune reactivity to self antigens; chronic inflammation of target organs expressing that specific autoantigen; activation and direct participation of invading mononuclear cells and resident tissue fibroblasts in organ damage. Over 25 different quantitative trait loci (QTL) regulating arthritis severity and autoantibody in rats with CIA are mapped. QTL‐congenic strains show that certain CIA–QTLs can modulate arthritis independently. These monogenic models are proving to be highly informative for fine mapping and function studies, revealing gender effects and evidence of gene clusters. Recent genome scans of RA populations identified RA‐susceptibility loci in chromosome regions homologous to rat chromosomal segments housing CIA–QTLs. Also, CIA–QTLs frequently co‐localize with susceptibility QTLs mapped in other rat arthritis models induced with non‐immunogenic adjuvant oils and/or in rat autoimmune models of multiple sclerosis and diabetes. Common autoimmunity genes and inflammation genes important to several human diseases are likely being detected in the various rat disease models. Continued dissection of the genetic underpinnings of rat arthritis models should provide candidate genes for investigation in human patients and lead to a clearer understanding of the complex genetics of RA.
Conditioning in the rat: an in vivo model to investigate the molecular mechanisms and clinical implications of brain–immune communication
Authors: Exton Michael S. , Herklotz Juliane , Westermann Jürgen , Schedlowski Manfred
Published: March 2003

Summary: A wealth of in vitro and ex vivo evidence has described both close anatomical interaction and functional bi‐directional communication between the immune and central nervous systems (CNS). These data have provided a framework for understanding the physiological mechanisms whereby behavioural factors may impact immune‐related disease. An understanding of this interaction, however, as well as verification of the biological relevance of communication among these systems, requires in vivo animal modelling. The development of psychoneuroimmunological models in the laboratory rat has played a key role in advancing the understanding of the influence of behaviour on immune status. One such paradigm is the behavioural conditioning of immune function in the rat. This elegant model is characterised by the ability to examine simultaneously both afferent and efferent brain–immune communication. Specifically, the role of peripheral cytokines in signalling the brain, as well as their anatomical and cellular targets in the CNS, can be identified. On the other hand, the neural and humoral pathways whereby the CNS influences the function and distribution of peripheral immunocytes can be demonstrated, together with the target hormone receptors on immunocompetent cells. Finally, the in vivo biological relevance of brain–immune communication is revealed by behavioural conditioning, demonstrating that clinically relevant conditions such as heart allograft survival can be modified by behavioural processes. Behavioural conditioning thereby provides an excellent example of the utility of in vivo laboratory rat models in psychoneuroimmunology research. Such paradigms not only provide a more complete knowledge of CNS–immune system interaction, but are the platform for determining potential clinical application of this information.
Gastrointestinal eosinophils
Authors: Rothenberg Marc E. , Mishra Anil , Brandt Eric B. , Hogan Simon P.
Published: March 2003

Summary: The gut‐associated lymphoid tissue (GALT) is composed of lymphocytes residing in Peyer's patches, lamina propria, and intraepithelial compartments. In addition to these features which distinguish GALT from other peripheral sites of the immune system, the gastrointestinal immune system is also composed of resident eosinophils. Eosinophils are generally considered to be peripheral blood leukocytes that have an important pro‐inflammatory role in various immune disorders. Although most research concerning this cell has focused on understanding its trafficking and function in the blood and lung, recent studies have also started to elucidate its regulation and function in the gastrointestinal tract. Interestingly, eosinophil numbers in the gastrointestinal tract are substantially higher than in other tissues. At baseline (healthy conditions), most eosinophils reside in the lamina propria in the stomach and intestine. Eosinophil homing to these sites occurs during embryonic development and their levels in perinatal mice are comparable to those in adults, indicating that their homing is not dependent upon the presence of intestinal flora. Furthermore, eosinophil localization to the lamina propria at baseline is critically regulated by eotaxin, a chemokine constitutively expressed throughout the gastrointestinal tract. Although eotaxin is required for eosinophil homing, its expression in the esophagus is not sufficient for eosinophil accumulation, since this organ is devoid of eosinophils at baseline. During Th2‐associated inflammatory conditions (e.g. interleukin (IL)‐5 overexpression or oral allergen challenge), marked increases of eosinophils occur not only in the lamina propria but also in Peyer's patches. The accumulation of Peyer's patch eosinophils, which mainly occurs in the outer cortex and interfollicular regions, is critically regulated by IL‐5 and less significantly by eotaxin, suggesting the involvement of other eosinophil chemokines in this lymphoid compartment. Preliminary investigations have shown that gastrointestinal eosinophils express the α4β7 integrin and that this molecule is responsible, in part, for eosinophil homing. In summary, eosinophils are resident cells of the gastrointestinal immune system whose levels can be induced by antigen exposure under Th2 conditions, in a manner that is critically regulated by eotaxin and IL‐5. We propose that eosinophils are integral members of the gastrointestinal immune system and are likely to be important in innate, regulatory and inflammatory immune responses.

This work was supported in part by the National Health Medical Research Council (Australia) C.J. Martin Post‐doctoral Fellowship (S.P.H.), the Jaffe Family Fund of the American Academy of Allergy, Asthma, and Immunology (S.P.H.), NIH grant R01 AI45898 (M.E.R.) and the Human Frontier Science Program (M.E.R.). The authors wish to thank Drs. K. Frank Austen, Mitchell Cohen, Paul Foster, Glenn Furuta, and Nives Zimmermann for helpful discussions, as well as numerous other colleagues.
Transdifferentiation and nuclear reprogramming in hematopoietic development and neoplasia
Authors: French Samuel W. , Hoyer Katrina K. , Shen Rhine R. , Teitell Michael A.
Published: March 2003

Summary:  Cell transplantation and tissue regeneration studies indicate a surprisingly broad developmental potential for lineage‐committed hematopoietic stem cells (HSCs). Under these conditions HSCs transition into myocytes, neurons, hepatocytes or other types of nonhematopoietic effector cells. Equally impressive is the progression of committed neuronal stem cells (NSCs) to functional blood elements. Although critical cell‐of‐origin issues remain unresolved, the possibility of lineage switching is strengthened by a few well‐controlled examples of cell‐type conversion. At the molecular level, switching probably initiates from environmental signals that induce epigenetic modifications, resulting in changes in chromatin configuration. In turn, these changes affect patterns of gene expression that mediate divergent developmental programs. This review examines recent findings in nuclear reprogramming and cell fusion as potential causative mechanisms for transdifferentiation during normal and malignant hematopoiesis.
The role of Notch signaling during hematopoietic lineage commitment
Authors: Radtke Freddy , Wilson Anne , Ernst Bettina , MacDonald H. Robson
Published: March 2003

Summary: Over the last few years a vast amount of progress has been made in identifying mechanisms controlling lineage commitment and plasticity of hematopoietic precursors to different lymphoid or myeloid lineages. This has been due largely to the ability to identify and isolate rare cell populations in order to investigate their developmental potential, together with the development of inducible and/or tissue specific targeting technology. One family of proteins that has been postulated to be involved in hematopoietic stem cell maintenance as well as in multiple commitment processes during T cell development is the Notch receptors and their ligands. In this review we will summarize recent findings and controversies regarding the role of Notch signaling in the myeloid and lymphoid systems.
Lineage plasticity and commitment in T‐cell development
Authors: Rothenberg Ellen V. , Dionne Christopher J.
Published: March 2003

Summary: The earliest stages of intrathymic T‐cell development include not only the acquisition of T‐cell characteristics but also programmed loss of potentials for B, natural killer, and dendritic cell development. Evidence from genetics and cell‐transfer studies suggests an order and some components of the mechanisms involved in loss of these options, but some of the interpretations conflict. The conflicts can be resolved by a view that postulates overlapping windows of developmental opportunity and individual mechanisms regulating progression along each pathway. This view is consistent with molecular evidence for the expression patterns of positive regulators of non‐T developmental pathways, SCL, PU.1 and Id2, in early thymocytes. To some extent, overexpression of such regulators redirects thymocyte development in vitro. Specific commitment functions may normally terminate this developmental plasticity. Both PU.1 overexpression and stimulation of ectopically expressed growth factor receptors can perturb T‐ and myeloid/dendritic‐cell divergence, but only in permissive stages. A cell‐line system that approximates DN3‐stage thymocytes reveals that PU.1 can alter specification even in a homogeneous population. However, the response of the population to PU.1 is sharply discontinuous. These studies show a critical role for regulatory context in restricting plasticity, which is probably maintained by interacting transcription factor networks.
Changes in actin dynamics at the T‐cell/APC interface: implications for T‐cell anergy?
Authors: Sechi Antonio S. , Buer Jan , Wehland Jürgen , Probst‐Kepper Michael
Published: March 2003

Summary: Over the past 20 years the role of the actin cytoskeleton in the formation of the immunological synapse and in T‐cell activation has been the subject of intense scrutiny. T‐cell receptor (TCR) signaling leads to tyrosine phosphorylation of numerous adapter proteins whose function is to relay signals to downstream components of the TCR signaling pathway and, in particular, to molecules implicated in remodeling the actin cytoskeleton. Here, we discuss how signals from the TCR converge on two key regulators of the actin cytoskeleton, Ena/vasodilator‐stimulated phosphoproteins (VASPs) and the actin‐related protein (ARP2/3) complex. We also discuss the implications of TCR signaling in the process of T‐cell anergy with particular emphasis on the actin remodeling and molecules involved in the control of T‐cell proliferation.
An architectural perspective on signaling by the pre‐, αβ and γδ T cell receptors
Authors: Hayes Sandra M. , Shores Elizabeth W. , Love Paul E.
Published: March 2003

The T cell antigen receptor (TCR) is a multimeric complex composed of an antigen‐binding clonotypic heterodimer and a signal transducing complex consisting of the CD3 dimers (CD3γε and CD3δε) and a TCR‐ζ homodimer. In all jawed vertebrates there are two T cell lineages, αβ and γδ, distinguished by the clonotypic subunits contained within their TCRs (TCR‐α and ‐β or TCR‐γ and ‐δ, respectively). A third receptor complex, the preTCR, is only expressed on immature T cells. The preTCR, which contains the invariant pre‐Tα (pTα) chain in lieu of TCR‐α, plays a critical role in the early development of αβ lineage cells. The subunit composition of the signal transducing complexes of the pre‐, αβ‐ and γδTCRs was previously thought to be identical. However, recent data demonstrate that there are significant differences in the signal transducing complexes of these three TCRs. For example, αβTCRs contain both CD3γε and CD3δε dimers, whereas γδTCRs contain only CD3γε dimers. Moreover, preTCR function appears to be unaffected in the absence of CD3δ, suggesting that CD3δε dimers are dispensable for pre‐TCR assembly. In this review, we summarize current data relating to the subunit composition of the pre‐, αβ‐ and γδTCRs and discuss how these structural differences may impact receptor signaling and αβ/γδ lineage determination.
Ursodeoxycholic acid reduces expression of heat shock proteins in primary biliary cirrhosis
Authors: Sakisaka Shotaro , Koga Hironori , Sasatomi Kurumi , Ohishi Masahito , Kawaguchi Takumi , Harada Masaru , Taniguchi Eitaro , Uchimura Yasuyo , Ueno Takato , Sata Michio , Tanikawa Kyuichi
Published: March 2003

Abstract: Background/Aims: To identify injured cells in the liver of patients with primary biliary cirrhosis (PBC) and to determine the effects of ursodeoxycholic acid (UDCA) on these cells, we examined the cellular expression of heat shock proteins (HSPs) in PBC both before and after treatment with UDCA. Methods: Expression of HSP70 and ubiquitin in PBC livers (n=34) was evaluated immunohistochemically as well as by immunoblot analysis, and compared with chronic viral hepatitis type C (n=9), primary sclerosing cholangitis (n=8), and controls (n=7). Results: Immunoblot analysis demonstrated a marked expression of HSP70 and ubiquitin in PBC. Immunohistochemical staining for both HSP70 and ubiquitin was observed to be strong in biliary epithelial cells (BECs) and moderate in both hepatocytes and arteries in PBC. Cellular labelling rates for HSP70 and ubiquitin of bile ducts in PBC were significantly higher (p<0.01) than those in chronic viral hepatitis type C, primary sclerosing cholangitis, or controls. The labelling rates for HSP70 and ubiquitin in bile ducts and in hepatocytes were significantly decreased (p<0.01) after treatment with UDCA in PBC. Conclusions: The present data suggest that BECs and hepatocytes significantly express HSPs even in the early stages of PBC, and that UDCA treatment significantly improves their condition. The immunohistochemical evaluation of HSPs is a valid and sensitive means to identify injured cells in PBC.
Expression of gap junction protein connexin 32 in chronic liver diseases
Authors: Yamaoka Kazuaki , Nouchi Toshihiko , Kohashi Takahiro , Marumo Fumiaki , Sato Chifumi
Published: March 2003

Abstract: Background: Gap junctions contain intercellular channels through which contacting cells communicate directly. The expression of connexin 32, a major gap junction protein in the liver, during the progression of chronic liver diseases has not yet been clarified. Methods: Immunohistochemical staining was performed using anti‐connexin 32 antibody on 6 specimens of normal human liver, 7 of chronic viral hepatitis, and 7 of liver cirrhosis. Results: The number of gap junction plaques in chronic viral hepatitis and liver cirrhosis was significantly smaller than that in normal liver (10350±2180 and 7550±3040 vs 22560±3700 spots/mm2, p<0.01). The number of gap junction plaques tended to be lower in liver cirrhosis than in chronic viral hepatitis. Conclusion: These results suggest that in chronic liver diseases impaired intercellular communication between hepatocytes occurs.
The liver in collagen diseases: pathologic study of 160 cases with particular reference to hepatic arteritis, primary biliary cirrhosis, autoimmune hepatitis and nodular regenerative hyperplasia of the liver
Authors: Matsumoto Toshiharu , Kobayashi Shigeto , Shimizu Hidetaka , Nakajima Mikako , Watanabe Sumio , Kitami Noriyuki , Sato Nobuhiro , Abe Hiroshi , Aoki Yuuji , Hoshi Tanji , Hashimoto Hiroshi
Published: March 2003

Abstract: Aims/Background: Among patients with collagen diseases, liver enzyme abnormalities are a relatively common phenomenon. To establish the liver pathology in collagen diseases, detailed pathologic studies were performed on the hepatic diseases in many patients, including various kinds of collagen diseases. Methods: The livers from 160 patients (120 autopsy and 40 liver biopsy patients) were examined pathologically: 73 with systemic lupus erythematosus (SLE), 32 with rheumatoid arthritis (RA), 18 with polymyositis and dermatomyositis (PM and DM), 15 with systemic sclerosis (SSc), 11 with mixed connective tissue disease (MCTD) and 11 with polyarteritis nodosa (PAN). Results: Liver diseases were divided into three groups: hepatic arteritis, liver diseases associated with collagen diseases (primary biliary cirrhosis, PBC; autoimmune hepatitis, AIH; nodular regenerative hyperplasia of the liver, NRH) and other liver diseases. Hepatic arteritis presenting the features of the PAN type of necrotizing arteritis was found in 27 autopsy patients. The incidence of arteritis in autopsy patients was 100% in PAN and 8.3–25% in other collagen diseases. Primary biliary cirrhosis was observed in 9 patients, 7 of whom (3 with SSc, 2 with RA, 1 with PM and DM, and 1 with MCTD) had antimitochondrial antibodies (AMA)‐positive PBC, and 2 SLE patients had AMA‐negative PBC. Three patients (2 with SLE and 1 with MCTD) were diagnosed clinicopathologically as having AIH. However, 3 patients (1 with SLE, 1 with MCTD and 1 with PM and DM) with clinical, biochemical and serologic data indicating probable AIH were excluded from the group with AIH association because of the liver histology (no characteristic features of AIH) and clinical course. These results indicated that data without histologic assessments of the liver are not adequate for diagnosing AIH in collagen diseases. Nodular regenerative hyperplasia of the liver was observed in 7 patients (5 with SLE, 1 with SSc and 1 with PAN). Conclusion: The present study offers data that are useful for the diagnosis and treatment of patients with collagen diseases and liver abnormalities.