bluuebunny/crossref_metadata_2025 huggingface dataset:
CD147 monoclonal antibodies induce homotypic cell aggregation of monocytic cell line U937 via LFA‐1/ICAM‐1 pathway
Authors: KASINRERK  , TOKRASINWIT  , PHUNPAE
Published: March 2003

CD147 is a 50 000–60 000 MW glycoprotein of the immunoglobulin superfamily broadly expressed on haemopoietic cell lines and peripheral blood cells. In the present study, six monoclonal antibodies (mAbs) directed against the CD147 protein were generated. The antigen defined by the generated CD147 mAbs is widely expressed on haemopoietic cell lines, peripheral blood cells and is a lymphocyte activation‐associated cell surface molecule. The generated CD147 mAbs precipitated a broad protein band from U937 cells of 45 000–65 000 MW under reducing conditions. Functional analysis indicated that the CD147 mAbs markedly induced homotypic cell aggregation of U937 cells, but not K562 cells. The CD147 mAb‐induced cell aggregation was inhibited by leucocyte function‐antigen‐1 (LFA‐1) and intercellular adhesion molecule‐1 (ICAM‐1) mAbs. However, the expression of LFA‐1 and ICAM‐1 molecules on U937 was not altered by CD147 mAb treatment. The U937 cell aggregation induced by CD147 mAb was also inhibited by ethylenediamine tetra‐acetic acid (EDTA), sodium azide and when incubated at 4°. We therefore propose that the binding of CD147 mAb to CD147 molecule, which mimics the natural ligand binding, may generate intracellular signals that activate LFA‐1/ICAM‐1 intercellular adhesion pathway.
Synovial fluid T cells from patients with rheumatoid arthritis are refractory to the T helper type 2 differentiation‐inducing effects of interleukin‐4
Authors: ISOMÄKI  , LUUKKAINEN  , LASSILA  , TOIVANEN  , PUNNONEN
Published: March 2003

The balance between T helper type 1 (Th1) and Th2 cytokines is thought to be important in the initiation and outcome of autoimmune diseases. The goal of the present study was to compare the production of interferon‐γ (IFN‐γ) and interleukin‐4 (IL‐4) by synovial fluid (SF) and peripheral blood (PB) CD4+ and CD8+ cells from patients with rheumatoid arthritis (RA) using three‐colour immunofluorescence staining and flow cytometry, and to investigate the capacity of IL‐4, IL‐10 and IL‐12 to modify the cytokine production profile of SF T cells. The frequency of IFN‐γ‐producing CD4+ and CD8+ cells was significantly increased in SF when compared with PB. In contrast to IFN‐γ, the expression of IL‐4 in SF and PB T cells was comparable. The majority of IL‐4‐producing cells in SF belonged to Th0/T cytotoxic (Tc) type 0 phenotype, whereas there were significantly more Th2/Tc2 cells in PB than in SF. Interestingly, IL‐4 was unable to induce differentiation of non‐adherent SF mononuclear cells (SFMC) into Th2 cells, whereas PB mononuclear cells (PBMC) under similar culture conditions differentiated into cells producing high levels of IL‐4, IL‐10 and IL‐13. In contrast, there were no major differences in the effects of IL‐10 and IL‐12 on the cytokine production profile of SFMC when compared with PBMC. Taken together, the present results suggest that SF T cells from patients with RA are terminally differentiated into Th1/Tc1‐like phenotype, and Th2/Tc2 differentiation‐inducing agents, such as IL‐4, may not be able to reverse the inflammatory process occurring in the joints.
Involvement of p38 mitogen‐activated protein kinase in lipopolysaccharide‐induced iNOS and COX‐2 expression in J774 macrophages
Authors: CHEN  , CHEN  , LIN
Published: March 2003

Both the nitrite and prostaglandin E2 (PGE2) release caused by lipopolysaccharide (LPS) in J774 macrophages are inhibited by SB 203580, a specific p38 mitogen‐activated protein kinase (MAPK) inhibitor, in a concentration‐dependent manner. The 50% inhibitory concentration (IC50) for nitrite and PGE2 responses was 1 μm and 0·5 μm, respectively. Inhibition was marked following simultaneous treatment with SB 203580 and LPS, and was much reduced when SB 203580 was added 6 hr after LPS treatment. In parallel, LPS induction of inducible NO synthase (iNOS) and cyclo‐oxygenase‐2 (COX‐2) proteins and their steady‐state levels of mRNA were reduced by SB 203580. LPS activation of nuclear factor‐kappa B (NF‐κB), activator protein‐1 (AP‐1) and p38 MAPK was also inhibited by SB 203580. These results suggest a crucial role of p38 MAPK in regulation of the transcriptional level of endotoxin LPS‐induced iNOS and COX‐2 protein expression.
Characterization ofBartonella henselae‐specific immunity in BALB/c mice
Authors: Karem  , Dubois  , Mcgill  , Regnery
Published: March 2003

BALB/c mice were inoculated withBartonella henselaeby both systemic and mucosal routes. Culture analysis of tissues from mice infected intraperitoneally with a high dose ofB. henselaeyielded positive results 24 hr after infection. However, culture analysis of blood taken between 6 hr and 7 days after infection from groups receiving liveB. henselaewere negative. Following intraperitoneal infection,B. henselaewas detected by polymerase chain reaction in liver and mesenteric lymph nodes by 6 hr and up to 7 days after infection in liver, kidney and spleen tissue. Enzyme‐linked immunosorbent assay (ELISA) of serum samples collected as early as 13 days after infection indicated humoral immune responses toB. henselae. Specific humoral responses remained through week 6. Analysis of faecal samples revealed induction ofB. henselae‐specific immunoglobulin A by day 28 after infection. In addition, B. henselae‐specific cellular responses were indicated by a positive delayed‐type hypersensitivity and a T helper 1 (Th1) (CD4+T cell)‐type cytokine response followingin vitrostimulation of splenocytes. The significance and implications of these data in relation toB. henselaeinfections are discussed.
Age‐related alterations of somatic hypermutation and CDR3 lengths in human Vκ4‐expressing B lymphocytes
Authors: Troutaud  , Drouet  , Decourt  , Le Morvan  , Cogné
Published: March 2003

The lower avidity and/or affinity of antibodies generated by an aged immune system could be attributed to two major changes in the antibody repertoire: a shift in germline gene usage and a decrease in the rate of immunoglobulin hypermutation. In an attempt to identify the mechanisms involved in the observed humoral immune deficiency in the elderly, we studied whether differences in the somatic diversity of a particular Vκ region occurred with ageing. By using the polymerase chain reaction and sequencing, we analysed and compared Vκ4–Jκ rearrangements isolated from young (mean age 21 years) and aged (mean age 83 years) healthy adults. Mutations in the Vκ4 gene compared with the germline sequence were determined as well as the length and structure of the CDR3 sequence. We analysed in detail various mechanisms contributing to CDR3 and Vκ variability in rearrangements involving the Vκ4 gene. Our data revealed that, despite strong individual variations, significantly lower levels of somatic mutation were found in the aged group, both for complementarity‐determining regions (CDRs) and framework regions (FRs) encoding Vκ4 sequences. This decrease mostly affected mutations responsible for replacements and thus resulted in a lowered somatic diversification of the encoded Vκ4 proteins in aged individuals. Moreover, comparison of the CDR3 regions of the Vκ4–Cκ cDNA revealed changes in light‐chain junctional diversity that correlated with age. Altogether these data suggest an impaired light‐chain somatic diversity in connection with human senescence.
Altered distribution of intraglomerular immune complexes in C3‐deficient mice
Authors: Sheerin  , Springall  , Carroll  , Sacks
Published: March 2003

We have studied the role of complement in a model of glomerular inflammation induced by the in situ formation of immune complexes along the glomerular basement membrane. In C3‐deficient mice, produced by homologous recombination, immune complex formation occurs initially in the subendothelial site and progresses slowly to the subepithelial position, whereas wild‐type mice do not develop subendothelial deposits. In addition, the accumulation of electron‐dense deposits is greater in the complement‐deficient mice. Complement therefore influences glomerular handling of immune complexes, possibly because of changes in the physiochemical characteristics of the immune complexes. However, despite evidence of complement activation in the wild‐type mice, as demonstrated by immunohistochemical detection of C3, C4 and C9, the degree of proteinuria was similar in C3‐deficient mice. We conclude that, although complement is required for the normal glomerular metabolism of immune complexes, other, complement‐independent, factors are involved in the generation of glomerular injury in this model.
Inhibitory effects of endogenous and exogenous interferon‐γ on bronchial hyperresponsiveness, allergic inflammation and T‐helper 2 cytokines in Brown–Norway rats
Authors: Huang  , Macary  , Wilke  , Kemeny  , Chung
Published: March 2003

Interferon‐γ (IFN‐γ) is an important cytokine involved in the regulation of allergen‐induced immune responses. We examined the role of IFN‐γ in a Brown–Norway rat model of bronchial hyperresponsiveness (BHR) and airway eosinophilia, and its effects on the mRNA expression of T helper type 1 (Th1)/Th2 cytokine. Ovalbumin (OA)‐sensitized animals were given either exogenous IFN‐γ (105 U/rat over 3 days, intraperitoneally) or anti‐IFN‐γ blocking antibody (DB‐1 0·3 mg/rat, intravenously) prior to exposure to OA aerosol and were studied 18–24 hr later. In sensitized animals, OA induced significant BHR, accumulation of eosinophils, T lymphocytes and neutrophils in bronchoalveolar lavage (BAL) fluid, and also increased eosinophils and CD8+ T cells in the airways. Exogenous IFN‐γ attenuated allergen‐induced BHR (P<0·02, compared with sham‐treated animals) together with a significant reduction in eosinophil and neutrophil numbers in BAL fluid (P<0·005), and eosinophils and CD8+ T cells in airways (P<0·05). By contrast, anti‐IFN‐γ antibody increased airway CD4+ T cells and BHR. Using reverse transcriptase–polymerase chain reaction, significant increases in Th2 [interleukin‐4 (IL‐4), IL‐5 and IL‐10], and IFN‐γ cytokine mRNA were found in the lungs of sensitized and OA‐exposed animals, while exogenous IFN‐γ significantly suppressed IL‐4, IL‐5 and IL‐10 mRNA expression, and anti‐IFN‐γ antibody increased IL‐4 and IL‐5 mRNA expression. These results indicate that Th1 effects, such as those mediated by IFN‐γ, play a down‐regulatory role to suppress the Th2 responses associated with allergen‐induced BHR and eosinophilic inflammation.
Anterior chamber‐associated immune deviation‐inducing cells activate T cells, and rescue them from antigen‐induced apoptosis
Authors: Takeuchi M. , Alard P. , Verbik D. , Ksander B. , Streilein J. W.
Published: March 2003

Immune responses to antigens injected into the anterior chamber of the eye are devoid of T helper 1 (Th1)‐type responses of the delayed hypersensitivity type, which has been termed anterior chamber‐associated immune deviation (ACAID). Recently, it has been found that peritoneal exudate cells (PEC) from normal mice can be made to acquire the capacity to induce ACAID in vivo when the cells are pulsed with antigen in vitro in the presence of transforming growth factor‐β2 (TGF‐β2), a major cytokine in the ocular microenvironment. We now report that when ovalbumin (OVA)‐specific T cells from DO11.10 transgenic mice, or from OVA‐primed normal mice, were activated in vitro by normal (untreated) PEC pulsed with OVA, the responding T cells were induced to undergo apoptosis. However, when PEC were first treated with TGF‐β2 and then used to stimulate DO11.10 T cells in the presence of OVA, T‐cell proliferation occurred without evidence of increased apoptosis. The ability of TGF‐β2 to rescue responding T cells from apoptosis rested with the capacity of this cytokine to inhibit interleukin‐12 (IL‐12) production by PEC. Untreated PEC produced large amounts of IL‐12 upon interaction with responding T cells. Under these conditions, tumour necrosis factor‐α (TNF‐α) production was up‐regulated, and this cytokine, in turn, triggered apoptosis among T cells stimulated with OVA‐pulsed PEC. From these results, we conclude that TGF‐β2‐treated APC promote ACAID by rescuing antigen‐activated T cells from apoptosis, and by conferring upon these cells the capacity to down‐regulate delayed hypersensitivity.
Phenotypic analysis of peripheral CD4+ CD8+ T cells in the rat
Authors: Kenny E. , Mason D. , Pombo A. , Ramírez F.
Published: March 2003

Among peripheral T cells, the expression of CD4 and CD8 is almost mutually exclusive. However, here we show, using flow cytometric analysis, that ex vivo approximately 6% of rat T cells stained for both CD4 and CD8. These double positive cells were also detected by confocal microscopy. Only around 50% of double positive cells expressed the CD8β chain, the remaining cells expressed the CD8α chain alone. Double positive cells were blast‐like with a phenotype, distinct from that of either CD4 or CD8 single positive cells, suggestive of an activated state. Previous reports of double positive T cells have also suggested that coexpression of CD4 and CD8 is linked to the activation state of the cell. There was an indication that priming animals with a hapten‐carrier complex increased the ratio of CD8αα : αβ expressing double positive T cells, although we did not detect an increase in the frequency of double positive T cells following priming. We also show that the frequency of double positive cells was reduced following thymectomy and with age. In conclusion, these studies show that peripheral T cells expressing both CD4 and CD8 can be detected in the rat and that they are phenotypically distinct from CD4 and CD8 single positive T cells.
Mapping of the chicken immunoglobulin heavy‐chain constant region gene locus reveals an inverted α gene upstream of a condensed υ gene
Authors: Zhao Y. , Rabbani H. , Shimizu A. , Hammarström L.
Published: March 2003

Chicken antibodies are increasingly being used as diagnostic and therapeutic tools. As only the genomic organization of the µ encoding gene was previously known, we analysed the chicken immunoglobulin Y (IgY) and IgA (υ and α chain) immunoglobulin heavy‐chain constant region (IGHC) genes and the organization of the chicken IGHC locus. The α gene is encoded by four separate exons, whereas, surprisingly, there is no intervening DNA sequence between the CH1 and CH2 domains of the IgY heavy chain, which is thus encoded by three exons separated by two introns. DNA sequence analysis shows that the exon boundaries of the chicken IGHC genes are not consistent with published domain borders. Furthermore, differences in DNA sequence confirm the existence of IgY, IgA and IgM allotypes in chickens. Finally, our results show that the IGHC genes of chicken (IgY, IgA and IgM) are all colocated on chromosome E18C15W15, where the α gene is located upstream of the υ gene in an inverted transcriptional orientation. The distances between the µ and α genes and the α and υ genes are about 18 and 15 kilobases, respectively, and thus, the size of the whole chicken IGHC locus is approximately 67 kilobases.
Recombinant adenovirus vectors expressing interleukin‐5 and ‐6 specifically enhance mucosal immunoglobulin A responses in the lung
Authors: Braciak T. A. , Gallichan W. S. , Graham F. L. , Richards C. D. , Ramsay A. J. , Rosenthal K. L. , Gauldie J.
Published: March 2003

In this study, we have examined the in vivo effects of interleukin‐5 (IL‐5) and IL‐6 over‐expression on systemic and mucosal immune responses using recombinant human type 5 adenoviruses capable of expressing these cytokines upon infection. A recombinant adenovirus containing the murine IL‐5 gene within the E3 region was constructed and found to express high levels of IL‐5 protein both in vitro and in vivo. Intranasal inoculation of mice with this vector or a vector expressing murine IL‐6 increased adenovirus‐specific immunoglobulin A (IgA) titres in lung lavage fluid threefold compared with those elicited by control virus. The simultaneous expression of both cytokines by co‐inoculation altered the kinetics of the mucosal anti‐adenovirus IgA response and resulted in a more than additive increase in antibody titres. The co‐expression effect on IgA synthesis was not due to an increase in numbers of antigen‐specific resident lung tissue lymphocytes. When mucosal IgG responses were examined, IL‐6 expression had the largest impact on anti‐adenovirus levels, whereas co‐expression produced an intermediate response. Systemic immune responses were also affected by IL‐6 expression as a twofold increase in serum IgG anti‐adenovirus titres was observed after a secondary challenge with wild‐type adenovirus. These results demonstrate a relevant role for IL‐5 and IL‐6 in the development of mucosal immune responses in vivo and suggest that the incorporation of either IL‐5 and/or IL‐6 into recombinant adenovirus vectors may be a useful tool in the development of mucosal vaccines.
Inhibition of immunoglobulin E response to Japanese cedar pollen allergen (Cry j 1) in mice by DNA immunization: different outcomes dependent on the plasmid DNA inoculation method
Authors: Toda M. , Sato H. , Takebe Y. , Taniguchi Y. , Saito S. , Inouye S. , Takemori T. , Sakaguchi M.
Published: March 2003

To develop a new immunotherapy for Japanese cedar (Cryptomeria japonica; CJ) pollinosis, we evaluated the use of DNA immunization by inoculating mice with plasmid DNA encoding Cry j 1 as a CJ pollen major allergen (pCACJ1). Repeated intramuscular (i.m.) inoculation of BALB/c mice with pCACJ1 produced anti‐Cry j 1 antibody responses, which were predominately of the immunoglobulin G2a (IgG2a) type. Furthermore, this inoculation suppressed immunoglobulin E (IgE) and IgG1 antibody responses to subsequent alum‐precipitated Cry j 1 injections. Splenic T cells isolated from mice inoculated with pCACJ1 i.m. secreted interferon‐γ (IFN‐γ), but not interleukin (IL)‐4, in vitro upon stimulation with Cry j 1 as well as with p277–288, a peptide corresponding to the T‐cell epitope of Cry j 1. In contrast, inoculation of BALB/c mice with pCACJ1 by gene gun injection caused response predominantly of the IgG1 type, and enhanced production of anti‐Cry j 1 IgE antibodies to subsequent alum‐precipitated Cry j 1 injections. Splenic T cells isolated from pCACJ1‐innoculated mice by gene gun injection secreted both IFN‐γ and IL‐4 in vitro, upon stimulation with Cry j 1 as well as with p277–288. These findings suggest that i.m. inoculation with pCACJ1 effectively elicits Cry j 1‐specific T helper 1 (Th1)‐type immune responses, resulting in inhibition of the IgE response to Cry j 1.
Constitutive activation of Lck and Fyn tyrosine kinases in large granular lymphocytes infected with the γ‐herpesvirus agents of malignant catarrhal fever
Authors: Swa S. , Wright H. , Thomson J. , Reid H. , Haig D.
Published: March 2003

Large granular lymphocytes (LGL) with a T or natural killer (NK) lymphoblast morphology and indiscriminate (non‐major histocompatibility complex‐linked) cytotoxicity for a variety of target cells can be derived in culture from the tissues of animals infected with either alcelaphine herpesvirus‐1 (AlHV‐1) or ovine herpesvirus‐2 (OvHV‐2). In this study, LGL survival in the absence of exogenous interleukin‐2 was inhibited by the protein kinase inhibitor genestein, but not the p70 s6 kinase inhibitor rapamycin. Constitutive activation of the src kinases Lck and Fyn was demonstrated in a bovine LGL line infected with OvHV‐2 and in two rabbit LGL lines infected with AlHV‐1. The p44 erk1 and p42 erk2 mitogen‐activated protein kinases (MAPK) were also constitutively activated in the LGLs but not control T cells. Lck and Fyn kinase activity in the LGLs did not increase after mitogen (concanavalin A or concanavalin A plus phorbol ester) stimulation of the cells, in contrast to control T cells. Control T cells, but not the LGLs, proliferated after mitogen stimulation. An analysis of tyrosine phosphorylated proteins in the cells indicated that the LGLs exhibited some similarities and differences to activated control T cells. The results demonstrate that the activated phenotype of the LGLs, associated with malignant catarrhal fever virus infection and in the absence of exogenous interleukin‐2, involves constitutively activated Lck and Fyn kinases. These are normally crucial for the initial activation of T cells via several cell‐surface receptors (e.g. the T‐cell receptor and CD2). The inability of the LGLs to proliferate in response to mitogen may be due to an inability of Lck and Fyn to become further activated after mitogen stimulation.
Molecular structure of eight human autoreactive monoclonal antibodies
Authors: Aguilera I. , Melero J. , Nuñez‐Roldan A. , Sanchez B.
Published: March 2003

The heavy (H) and light (L) chain V‐region sequences of eight human autoreactive immunoglobulin M (IgM) monoclonal antibodies (mAbs: BY‐4, BY‐7, BY‐12, IRM‐3, IRM‐7, IRM‐8, IRM‐10 and CDC‐1) were determined at the cDNA level. All VH and VL families were identified. Four different VH families were represented, VH3 being the most common as five of the mAbs (BY‐7, BY‐12, IRM‐3, IRM‐8 and CDC‐1) used genetic elements of this family, whereas VH1, VH2 and VH4 were only present in IRM‐7, BY‐4 and IRM‐10, respectively. BY‐4, BY‐7, BY‐12, IRM‐7 and IRM‐10 reacted with a variety of self as well as non‐self antigens, thus exhibiting polyreactive behaviour. Comparison of the gene segments utilized by these mAbs with their germline counterparts revealed that the gene segments were close to germline configuration. The length of H‐CDR3 was found to be relatively long (27–60 nucleotides) among the polyreactive mAbs and the presence of Tyr and Trp residues in this region seems to be of vital importance for polyreactivity. We have analysed the utilization of gene elements and the presence of amino acid residues in regions particularly important for antigen binding, such as CDR. Common molecular features relating to the function of the mAbs are discussed.
Efficacy of cytokine gene transfection may differ for autologous and allogeneic tumour cell vaccines
Authors: Todryk S. M. , Birchall L. J. , Erlich R. , Halanek N. , Orleans‐Lindsay J. K. , Dalgleish A. G.
Published: March 2003

Whole tumour cells are a logical basis for generating immunity against the cancers they comprise or represent. A number of human trials have been initiated using cytokine‐transfected whole tumour cells of autologous (patient‐derived) or allogeneic [major histocompatibility complex (MHC)‐disparate] origin as vaccines. Although precedent exists for the efficacy of autologous‐transfected cell vaccines in animal models, little preclinical evidence confirms that these findings will extrapolate to allogeneic‐transfected cell vaccines. In order to address this issue a murine melanoma cell line (K1735) was transfected to secrete interleukin (IL)‐2, IL‐4, IL‐7 or granulocyte–macrophage colony‐stimulating factor (GM‐CSF); cytokines currently in use in trials. The efficacy of these cells as irradiated vaccines was tested head‐to‐head in syngeneic (C3H) mice and in MHC‐disparate (C57BL/6) mice, the former being subsequently challenged with K1735 cells and the latter with naturally cross‐reactive B16‐F10 melanoma cells. Whilst the GM‐CSF‐secreting vaccine was the most effective at generating protection in C3H mice, little enhancement in protection above the wild‐type vaccine was seen with any of the transfections for the allogeneic vaccines, even though the wild‐type vaccine was more effective than the autologous B16‐F10 vaccine. Anti‐tumour cytotoxic T‐lymphocyte (CTL) activity was detected in both models but did not correlate well with protection, whilst in vitro anti‐tumour interferon‐γ (IFN‐γ) secretion tended to be higher following the GM‐CSF‐secreting vaccine. Cytokine transfection of vaccines generally increased anti‐tumour CTL activity and IFN‐γ secretion (T helper type 1 response). Further studies in other model systems are required to confirm this apparent lack of benefit of cytokine transduction over wild‐type allogeneic vaccines, and to determine which in vitro assays will correlate best with protection in vivo.
The developing human immune system: T‐cell receptor repertoire of children and young adults shows a wide discrepancy in the frequency of persistent oligoclonal T‐cell expansions
Authors: Wedderburn L. R. , Patel A. , Varsani H. , Woo P.
Published: March 2003

While the T‐cell receptor (TCR) repertoire of the newborn is highly diverse, a gradual alteration in diversity of the expressed TCR repertoire, in particular the oligoclonality of CD8+ T cells, occurs with increasing age. The timing of the initiation of this process is unknown. These changes are associated with an accumulation of T‐cell expansions, thought to be in response to chronic antigen stimulation, frequently by persistent viruses such as Epstein–Barr virus (EBV) and cytomegalovirus (CMV). Using reverse transcription–polymerase chain reaction heteroduplex analysis we have characterized the TCR expression of CD4 and CD8 cells from healthy young children and adults in order to delineate the age range at which these oligoclonal populations appear. We demonstrate that considerable oligoclonality can occur, even in healthy young children, and also that these expanded clonotypes persist. These are shown by heteroduplex to be exclusively within the CD28− subpopulation. The presence of such oligoclonal expansions correlates closely with the percentage of CD8+ cells that have the CD28− phenotype. However, we also show that control of chronic infection with EBV or CMV may coexist with a highly diverse, polyclonal TCR repertoire well into adulthood. These studies suggest that many factors affect the overall regulation of clone size in response to chronic antigens during the development of the immune system.
Major histocompatibility complex class II invariant chain expression in non‐antigen‐presenting cells
Authors: Veenstra Hanne , Ferris William F. , Bouic Patrick J. D.
Published: March 2003

In contrast to the generally accepted belief, the major histocompatibility complex (MHC) class II invariant chain (Ii) is commonly expressed intracellularly in cells that do not present exogenous antigens. Such cells include resting peripheral blood T cells and natural killer (NK) cells. In T cells, the Ii is associated with a 77 000 molecular‐weight molecule (p77) that has yet to be identified. This molecule is co‐precipitated with the anti‐Ii monoclonal antibody (mAb) VCD‐1, but not with mAb BU‐45. This suggests that in the p77–Ii complex, the extracellular epitope of Ii recognized by BU‐45 is hidden, whereas the Ii epitope for VCD‐1 remains exposed. In antigen‐presenting cells (APCs), p77 association with the Ii was minimal, if detectable. The p77–Ii association in non‐professional APCs suggests that the Ii may have another, more general, function other than the one accepted in antigen presentation.
Role of chemokines and chemokine receptors in the gastrointestinal tract
Authors: Ajuebor Maureen N. , Swain Mark G.
Published: March 2003

The pathological association between leucocytes and gastrointestinal diseases has long been recognized. Chemokines are a large family of chemotactic cytokines whose fundamental role is the recruitment of leucocytes to tissues. Although chemokines and their receptors are considered to be mediators of inflammation and tissue injury in several inflammatory diseases, their precise role in the pathophysiology of gastrointestinal diseases remains incompletely understood. Nonetheless, by virtue of their expression and localization at sites of gastrointestinal tissue injury and inflammation, a number of investigators have suggested a vital role for chemokines and their receptors in the pathophysiology of gastrointestinal diseases. This short review examines the role of chemokines and their receptors in the gastrointestinal tract with an emphasis on their involvement in the regulation of intestinal and hepatic inflammation.
Interleukin‐7 inhibits pre‐T‐cell differentiation induced by the pre‐T‐cell receptor signal and the effect is mimicked by hGM‐CSF in hGM‐CSF receptor transgenic mice
Authors: Yasuda Yuko , Kaneko Azusa , Nishijima Ichiko , Miyatake Shoichiro , Arai Ken‐ichi
Published: March 2003

We have previously reported that human granulocyte–macrophage colony‐stimulating factor (hGM‐CSF) causes a stage‐specific inhibition of T‐cell receptor (TCR) αβ cell development in the thymus of transgenic mice constitutively expressing the hGM‐CSF receptor. Since it has been reported that the addition of interleukin‐7 (IL‐7) to fetal thymic organ culture (FTOC) has similar effects, we compared the effects of IL‐7 and hGM‐CSF on TCRαβ cell development in hGM‐CSF receptor transgenic mice. We reconstituted fetal lobes with sorted pre‐T, or post pre‐T CD4−CD8− precursor cells. The addition of either IL‐7 or hGM‐CSF to these cultures suppressed further differentiation of pre‐T cells but not post pre‐T cells. At the same time, the cell number was increased, suggesting that pre‐T‐cell proliferation is stimulated by these cytokines. Furthermore, the differentiation of recombination‐activating gene‐1 (RAG‐1)‐deficient pre‐T cells in response to anti‐CD3 antibody stimulation was suppressed by either IL‐7 or hGM‐CSF, suggesting that these cytokines inhibit the pre‐T‐cell receptor (pre‐TCR) signal. This inhibition is unexpected because the pre‐TCR signal and the IL‐7 signal have previously been considered to be co‐operative. Recent analysis of the downstream events of IL‐7 receptor and GM‐CSF receptor revealed that they share common signal transduction molecules. Our results show that IL‐7 is able to promote pre‐T cell proliferation and to suppress differentiation induced by the pre‐TCR signal. GM‐CSF can mimic these biological activities of IL‐7 when the pre‐T cells express GM‐CSF receptors. Our data suggest that both timing and level of activation of the IL‐7 signalling pathway must be precisely regulated to facilitate the differentiation of thymocytes.
Genomics and proteomics of allergic disease
Authors: Toda Masako , Ono Santa Jeremy
Published: March 2003

The world‐wide effort to identify susceptibility genes for allergic diseases is motivated by the conviction that the identification of disease genes may permit the design of new classes of anti‐inflammatory compounds. Molecules concerned with the allergic reaction, such as cytokines, chemokines, their receptors, major histocompatibility complex molecules, and transcription factors, could provide the candidate genes of the allergic diseases. On the basis of genetic studies, multiple research groups have attempted to identify a susceptibility gene for allergy using the candidate gene approach and/or genome‐wide screening. Both of these approaches suggest genetic heterogeneity of allergic diseases. Many variants of candidate genes are or are not associated with particular diseases in different ethnic groups and the function of variants is now being investigated. Based on the information accumulated thus far and the information on the human genome sequence, future advances in research on genetic factors for allergic diseases will be likely lead to the establishment of more effective prophylaxis and therapy for these diseases.
Type I interferon gene therapy protects against cytomegalovirus‐induced myocarditis
Authors: Cull Vanessa S. , Bartlett Emmalene J. , James Cassandra M.
Published: March 2003

Type I interferons (IFNs) are produced early in response to viral infection and modulate adaptive immunity. Previously we demonstrated localized protection against murine cytomegalovirus (MCMV) infection in IFN DNA‐inoculated mice. Here we examine the effect of seven IFN subtypes (IFNA1, A2, A4, A5, A6, A9 and B), administered by DNA inoculation, on systemic MCMV infection and myocarditis. IFN transgene expression altered the pathogenesis of MCMV infection with regard to virus titre and myocarditis. IFNA6 treatment reduced MCMV replication whilst IFNA5 and A2 enhanced virus replication. IFNA6, A9, and B treatment inhibited acute myocarditis. A T helper type 1‐like, antibody and cytokine, response correlated with decreased virus titre and myocarditis. In addition, IFNA6 was able to reduce chronic cardiac inflammation. This research into the effectiveness of seven type I IFNs, using DNA gene therapy, highlights the need for correct subtype usage in the treatment of disease. We demonstrate effective subtypes for treatment in both the acute and chronic phases of MCMV infection and the resultant development of myocarditis.
Effect of cell density on in vitro mouse immunoglobulin E production
Authors: Rabah Dania , Conrad Daniel H.
Published: March 2003

In vitro immunoglobulin E (IgE) production was found to be sensitive to increasing cell concentration in culture wells. While class switching to IgE is intact as suggested by surface IgE staining, ELISPOT analysis provided evidence that the differentiation of IgE committed B cells to the plasma cell stage was arrested at high cell doses. In fact, splitting the cells at higher concentrations after culture initiation increased IgE production. Cells plated at higher doses were found to be more prone to apoptosis as assessed by Annexin staining. Interestingly, inhibiting apoptosis by the use of the caspase inhibitor DEVD significantly increased IgE levels implicating apoptosis in the preferential deletion of IgE expressing cells. These data not only highlight the caveat against using a single B‐cell dose for IgE production in vitro but also suggest for the first time a possible IgE regulatory mechanism mediated by cell density.
Heritability estimates for the constitutional levels of the collectins mannan‐binding lectin and lung surfactant protein D. A study of unselected like‐sexed mono‐ and dizygotic twins at the age of 6–9 years
Authors: Husby Steffen , Herskind Anne Maria , Jensenius Jens Christian , Holmskov Uffe
Published: March 2003

The collectins mannan‐binding lectin (MBL) and lung surfactant protein D (SP‐D) play a significant role in innate immunity. Structural as wells as promoter variants are known for MBL and different alleles correlate with low MBL concentrations in serum and predispose to infectious diseases. Structural variants are also known for SP‐D but these have not been linked to disease states. The aim of the present study was to provide heritability estimates for the constitutional levels of MBL and SP‐D in children. A population of 26 monozygotic (MZ) and 36 dizygotic (DZ) like‐sexed twin pairs aged 6–9 years was studied. Intraclass correlations were significantly higher in MZ than in DZ twins, indicating substantial genetic influence on both MBL and SP‐D levels. Biometric model fitting showed that the estimated heritability was 0·96 (95% CI 0·92–0·97) for MBL with the presence of non‐additive genetic factors and non‐shared environmental factors and 0·91 (95% CI 0·83–0·95) for SP‐D with additive genetic and non‐shared environmental factors. The data indicate quantitatively very strong genetic dependence for the serum levels of both MBL and SP‐D.
Insight into the potential for DNA idiotypic fusion vaccines designed for patients by analysing xenogeneic anti‐idiotypic antibody responses
Authors: Forconi Francesco , King Catherine A. , Sahota Surinder S. , Kennaway Christopher K. , Russell Nigel H. , Stevenson Freda K.
Published: March 2003

DNA vaccines induce immune responses against encoded proteins, and have clear potential for cancer vaccines. For B‐cell tumours, idiotypic (Id) immunoglobulin encoded by the variable region genes provides a target antigen. When assembled as single chain Fv (scFv), and fused to an immunoenhancing sequence from tetanus toxin (TT), DNA fusion vaccines induce anti‐Id antibodies. In lymphoma models, these antibodies have a critical role in mediating protection. For application to patients with lymphoma, two questions arise: first, whether pre‐existing antibody against TT affects induction of anti‐scFv antibodies; second, whether individual human scFv fusion sequences are able to fold consistently to generate antibodies able to recognize private conformational Id determinants expressed by tumour cells. Using xenogeneic vaccination with scFv sequences from four patients, we have shown that pre‐existing anti‐TT immunity slows, but does not prevent, anti‐Id antibody responses. To determine folding, we have monitored the ability of nine DNAscFv–FrC patients' vaccines to induce xenogeneic anti‐Id antibodies. Antibodies were induced in all cases, and were strikingly specific for each patient's immunoglobulin with little cross‐reactivity between patients, even when similar VH or VL genes were involved. Blocking experiments with human serum confirmed reactivity against private determinants in 26–97% of total antibody. Both immunoglobulin G1 (IgG1) and IgG2a subclasses were present at 1·3 : 1–15 : 1 consistent with a T helper 2‐dominated response. Xenogeneic vaccination provides a simple route for testing individual patients' DNAscFv–FrC fusion vaccines, and offers a strategy for production of anti‐Id antibodies. The findings underpin the approach of DNA idiotypic fusion vaccination for patients with B‐cell tumours.
krox‐20/egr‐2 is up‐regulated following non‐specific and homophilic adhesion in rat macrophages
Authors: Hirano Seishiro , Anuradha Cunigaipur D. , Kanno Sanae
Published: March 2003

Macrophages are known to adhere to a plastic dish via β2 integrin (CR3) and scavenger receptors. Although their functions such as phagocytosis, endocytosis, and nitric oxide production have been investigated on adherent macrophages in vitro, very little is known about intracellular signals triggered by adhesion to a plastic dish. Recently we reported that the mRNA level of krox‐20/egr‐2 was significantly increased in rat alveolar macrophages following exposure to fibrous titanium dioxide particles. In the present study we report that up‐regulation of krox‐20/egr‐2 gene expression following adhesion to a plastic dish and homophilic adhesion in rat alveolar macrophages and rat macrophage cell line, NR8383. The mRNA level of krox‐20/egr‐2 increased with a peak 1 hr after adhesion to a plastic dish in both cell types. Piceatannol inhibited tyrosine‐phosphorylation of Syk and decreased both adhesion and krox‐20/egr‐2 mRNA level. In contrast staurosporine, a serine/threonine kinase inhibitor, increased adherence of macrophages and yet prohibited the adhesion‐dependent increase in krox‐20/egr‐2 gene expression. When NR8383 cells are cultured in suspension, the cells aggregated naturally and produced cell clumps. The mRNA level of krox‐20/egr‐2 also increased in response to the homophilic intercellular adhesion. The increased mRNA level of krox‐20/egr‐2 was not caused by inflammatory stimuli, because lipopolysaccharide did not affect the aggregation‐dependent up‐regulation of krox‐20/egr‐2 gene. The up‐regulation of krox‐20/egr‐2 gene due to the homophilic cell aggregation was also inhibited either by piceatannol or staurosporine. Those results suggest that krox‐20/egr‐2 gene expression is triggered by sensing non‐specific and homophilic cellular adhesion and the following phosphorylation of signal transducing proteins including Syk and staurosporine‐inhibitable kinases.
Both exogenous and endogenous interleukin‐10 affects the maturation of bone‐marrow‐derived dendritic cells in vitro and strongly influences T‐cell priming in vivo
Authors: Haase Claus , Jørgensen Trine N. , Michelsen Birgitte K.
Published: March 2003

In order to avoid autoimmunity and excessive tissue destruction, the action of certain immunoinhibitory substances are very important for negative regulation of the immune system. Interleukin‐10 (IL‐10) is an important immunoregulatory cytokine which is thought to negatively affect both T cells and antigen‐presenting cells in vivo. Adoptive transfer of IL‐10‐treated bone‐marrow‐derived dendritic cells (BMDCs) may be one therapeutic avenue to inhibit autoimmunity. In this study we present a comprehensive analysis of the effects of IL‐10 on murine BMDC. We demonstrate that IL‐10 can prevent BMDC maturation, as measured by both cytokine production and T‐cell priming capacity in vitro. Furthermore, we show that IL‐10 can inhibit DC maturation induced by strong stimulatory signals such as lipopolysaccharide or a mixture of cytokines (interferon‐γ, tumour necrosis factor‐α, IL‐4). Interestingly, maturation of both T helper 1‐ and T helper 2‐inducing DCs, characterized by the induction of high levels of interferon‐γ and IL‐4‐production by responding T cells, respectively, was inhibited by IL‐10 in vitro. Finally, our data suggest that both endogenous and exogenous IL‐10 affect the T‐cell stimulatory capacity of BMDCs after injection of in vitro‐treated BMDCs into naïve mice. These data both support existing data as well as point towards a new understanding of the many aspects of IL‐10‐mediated immunosuppression.
Three T‐cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, retain their immunogenicity and tolerogenicity in a linked peptide
Authors: Yoshitomi Tomomi , Hirahara Kazuki , Kawaguchi Junko , Serizawa Nobufusa , Taniguchi Yoshifumi , Saito Saburo , Sakaguchi Masahiro , Inouye Sakae , Shiraishi Akio
Published: March 2003

It has been demonstrated in detail that administration of a dominant T‐cell determinant to animals induces activation or immunological tolerance of T cells. However, it has not been determined whether multiple T‐cell determinants, when integrated into a single peptide, retain their potential to induce T‐cell activation and tolerance. We prepared a synthetic peptide comprising three T‐cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, and investigated the immunogenicity and tolerogenicity of each T‐cell determinant in the linked peptide by means of lymph node cell proliferation assays using mice. Lymph node cells from mice immunized with each of the three T‐cell determinants proliferated against the linked peptide in a dose‐dependent manner, similar to that of the immunized peptide. Lymph node cells from mice immunized with the linked peptide proliferated against all of the three T‐cell determinants. In addition, the degree of proliferation against the three T‐cell determinants occurred according to their original immunogenicity, as observed in the native protein antigens. Oral administration of the linked peptide to mice before they were immunized with Cry j 1 and Cry j 2 inhibited lymph node cell proliferation against the three T‐cell determinants, depending on the dose of the linked peptide administered. In conclusion, it was demonstrated that three T‐cell determinants retain their original immunogenicity and tolerogenicity in a linked peptide comprising them.
Induction of 4‐1BB (CD137) expression by DNA damaging agents in human T lymphocytes
Authors: Kim Kwang‐Mi , Kim Ho Won , Kim Jae‐Ouk , Baek Kyoung‐Min , Kim Joong Gon , Kang Chang‐Yuil
Published: March 2003

4‐1BB(CD137) is a member of the tumour necrosis factor receptor superfamily and is expressed on activated T cells, monocytes and natural killer (NK) cells. The interaction of 4‐1BB and 4‐1BB ligand provides a costimulatory signal leading to T‐cell activation. The expression of 4‐1BB has been known to be activation dependent. Interestingly, we found that expression of 4‐1BB increased in human peripheral blood mononuclear cells after exposure to mitomycin C. Thus, we tested whether the treatment with other DNA‐damaging agents, such as doxorubicin, bleomycin, and γ‐irradiation, could induce 4‐1BB expression. The data indicated that 4‐1BB expression increased dose‐dependently by these agents reaching maximum at 2–3 days after the exposure. We found that the major 4‐1BB‐expressing population was CD3+T cells, although a moderate number of CD14+cells and a few NKB1+cells also expressed 4‐1BB. The levels of 4‐1BB expression induced by anticancer drugs, were relatively lower than that induced by CD3 ligation. Interestingly, at subcytotoxic concentrations, doxorubicin and bleomycin considerably enhanced 4‐1BB expression induced by CD3 ligation in CEM cells. The ligation of the damage‐induced 4‐1BB by monoclonal antibody enhanced the viability and proliferating capacity of the cells. In conclusion, the expression of 4‐1BB might be one of the cellular responses of the immune cells against various genotoxic stresses.
Human CD8 T cells of the peripheral blood contain a low CD8 expressing cytotoxic/effector subpopulation
Authors: Trautmann Axel , Rückert Beate , Schmid‐Grendelmeier Peter , Niederer Eva , Bröcker Eva‐B. , Blaser Kurt , Akdis Cezmi A.
Published: March 2003

Heterogeneity of lymphocyte populations demonstrates the diversity of cellular immune responses and provide a better understanding of the immune system. CD3+ CD8+ T cells exhibit a low CD8 expressing (CD8low) population in flow cytometric analysis of peripheral blood T cells. In healthy donors, this population consists of 0·2–7·0% of all CD8 T cells. The majority of the CD8low T cell population showed an elevated expression of CD25, CD45RA, and CD95L, and low levels of CD28, CD62L and CD45RO. Circulating CD8low T cells resemble cytotoxic effector cells because they express cytolytic mediators and are able to execute cytotoxicity. A restricted T cell receptor profile with increased Vβ9, Vβ14 and Vβ23 expression was observed and the CD8low T cell population contain Epstein–Barr virus‐specific T cells. Therefore, the CD8low population represent a subset of activated CD8 effector T cells, resulting most probably from a continous and/or balanced immune response to intracellular pathogens.
A framework for creating hybrid‐open source software communities
Authors: Sharma Srinarayan , Sugumaran Vijayan , Rajagopalan Balaji
Published: March 2003

Abstract The open source software (OSS) model is a fundamentally new and revolutionary way to develop software. The success of the OSS model is also setting the stage for a structural change in the software industry; it is beginning to transform software industry from manufacturing to a service industry. Despite the success of the OSS model, for‐profit organizations are having difficulty building a business model around the open source paradigm. Whereas there are some isolated empirical studies, little rigorous research has been done on how traditional organizations can implement and benefit from OSS practices. This research explores how organizations can foster an environment similar to OSS to manage their software development efforts to reap its numerous advantages. Drawing on organizational theory, we develop a framework that guides the creation and management of a hybrid‐OSS community within an organization. We discuss the implications of this framework and suggest areas for future research.
Ikirara, a novel transposon family from the malaria vector mosquito, Anopheles gambiae
Authors: Romans P. , Bhattacharyya R. K. , Colavita A.
Published: March 2003

Members of a novel transposon family, Ikirara, were found in the genome of the malaria vector Anopheles gambiae. They are most abundant in A. gambiae sensu stricto, but related sequences were found in all four other tested members of this species complex. No relatives were found in A. funestus or A. stephensi. Ikirara1, the first isolated family member, was found between two of the tandem Vitellogenin (Vg) genes. Because it was found at this location in G3 and only one of nine other A. gambiae s.s. strains examined, and because its 216 bp inverted terminal repeats are 100% identical, transposition to this locus may have been recent. Ikirara1 inverted repeat terminal sequences are similar to those of DNA to DNA transposons of the mariner/Tc1 and hAT superfamilies. Also similar to mariner/Tc1 elements, insertion of Ikirara1 apparently created a duplication of the dinucleotide TA at the target site.