bluuebunny/crossref_metadata_2025 huggingface dataset:
Granulocyte–macrophage colony‐stimulating factor modulates lipopolysaccharide (LPS)‐binding and LPS‐response of human macrophages: inverse regulation of tumour necrosis factor‐α and interleukin‐10
Authors: Kreutz M. , Hennemann B. , Ackermann U. , Grage‐griebenow E. , Krause S. W. , Andreesen R.
Published: March 2003

Granulocyte–macrophage colony‐stimulating factor (GM‐CSF) is a well‐known stimulus for the activation, differentiation and survival of monocytes (MO). Up to now most investigations focused on the short‐term effects of GM‐CSF. In this study we investigated the effects of GM‐CSF on the long‐term differentiation of human MO in the presence of serum. We found that MO‐derived macrophages (Mφ) cultured with serum plus GM‐CSF (GM‐Mφ) were different from control Mφ (SER‐Mφ) in terms of lipopolysaccharide (LPS)‐stimulated cytokine release: GM‐Mφ showed an increased tumour necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6) production, especially at lower LPS concentrations, but the secretion of IL‐10 was diminished. In addition, GM‐Mφ secreted TNF‐α but not IL‐6 and IL‐10, spontaneously. The spontaneous TNF‐α production was not due to LPS contamination as it could not be blocked by anti‐CD14 antibody. Flow cytometry revealed, however, that the receptor for LPS, CD14, was up‐regulated on GM‐Mφ and those Mφ released twice as much soluble CD14 into the supernatant as compared with SER‐Mφ. The higher CD14 expression also resulted in an enhanced LPS‐binding capacity of GM‐Mφ. Furthermore, the LPS‐response of GM‐Mφ could only be blocked by about fourfold higher concentration of anti‐CD14 antibody compared with SER‐Mφ. In summary, GM‐CSF promotes the generation of a pro‐inflammatory type of Mφ in two different ways: first, the down‐regulation of autocrine IL‐10 production increases the release of cytokines such as IL‐6 and TNF‐α and second, the up‐regulation of membrane and soluble CD14 expression leads to a higher sensitivity towards LPS‐stimulation.
Transcriptional and post‐transcriptional regulation of monocyte chemoattractant protein‐3 gene expression in human endothelial cells by phorbol ester andcAMP signalling
Authors: Kondo A. , Isaji S. , Nishimura Y. , Tanaka T.
Published: March 2003

Monocyte chemoattractant protein‐3 (MCP‐3) is one of the most broadly active chemokines, potentially inducing chemotaxis of all leucocytic cells. In the present study, we examined the regulation of MCP‐3 mRNA and protein production in endothelial cells by protein kinase C (PKC) activator, phorbol 12‐myristate 13‐acetate (PMA) and cAMP signalling. On stimulation of endothelial cells with 10 n m PMA, MCP‐3 mRNA increased to 300‐fold the basal level at 3 hr and rapidly declined to 0·2‐fold the basal level at 24 hr. PMA‐induced MCP‐3 mRNA and protein production of human endothelial cells were partially inhibited by pretreatment with the adenylate cyclase activator, forskolin, or membrane‐permeable cAMP derivative. The PMA‐induced MCP‐3 mRNA increase was almost abrogated when cells were pretreated with cycloheximide (CHX). Forskolin inhibited the transcription of PMA‐induced MCP‐3 gene expression. Following PMA stimulation for 3 hr, subsequent addition of actinomycin D suppressed the rapid decay of PMA‐induced MCP‐3 mRNA. These results suggest that PMA induces the transcriptional activation of the MCP‐3 gene through de novo protein synthesis and the rapid decay of PMA‐induced MCP‐3 mRNA through de novo synthesis of adenosine/uridine (AU)‐rich element binding proteins and cAMP signalling inhibits the PMA‐induced transcriptional activation of the MCP‐3 gene expression.
Characterization of the porcine γδ T‐cell receptor structure and cellular distribution by monoclonal antibody PPT27
Authors: Yang H. , Parkhouse R. M. E.
Published: March 2003

The T‐cell receptor (TCR) is the critical structure involved in antigen recognition of T lymphocytes. Although the pig has a large proportion of circulating T lymphocytes bearing the γδ TCR, their study has been impeded due to the lack of specific antibodies. Here a monoclonal antibody (mAb) PPT27 directed to γδ TCR is described. Flow cytometry analyses showed that the mAb recognized a subset of T lymphocytes of which the majority expressed no CD2, CD4 and CD8 whilst the minority bore CD2 and CD8. The mAb precipitated a protein of 86 000 MW under non‐reducing conditions and a doublet of 43 000 MW under reducing conditions from peripheral blood T lymphocytes lysed in nonidet P‐40 buffer, whilst it precipitated the CD3–TCR complex from the cells lysed in digitonin. Further analysis revealed that the antibody recognized the majority, but not all, of the γδ T cells, suggesting that there may be more isotypes of γδ TCR than currently believed. The antibody was unable to stimulate γδ T cells to proliferate in vitro, suggesting that these cells are activated by a different activation mechanism from that of αβ T cells.
Common antigenicity between Japanese cedar (Cryptomeria japonica) pollen and Japanese cypress (Chamaecyparis obtusa) pollen, II. Determination of the cross‐reacting T‐cell epitope of Cry j 1 and Cha o 1 in mice
Authors: Ohno N. , Ide T. , Sakaguchi M. , Inouye S. , Saito S.
Published: March 2003

We have previously detected common antigenicity between Cry j 1 and Cha o 1 in B10.S mice. B10.S mice immunized with Cry j 1‐ or Cha o 1‐generated T cells and antibodies reactive to both allergens. In the present study, we investigated the cross‐reacting and Cry j 1‐specific T‐cell epitopes in B10.S mice. Lymph node cells from B10.S mice immunized with Cry j 1 recognized Cry j 1 p111–130, p211–230, and p310–330 as well as Cha o 1 p209–228. The existence of the cross‐reacting T‐cell epitope in Cry j 1 and Cha o 1 was confirmed by the response of newly established p211–230‐specific and Cha o 1 p209–228‐specific T‐cell lines. The minimum peptide sequence (p213–224) of the cross‐reacting T‐cell epitope was identical in Cry j 1 and Cha o 1. These findings clearly demonstrate that common antigenicity at the T‐cell level between Japanese cedar and cypress pollen allergens was caused by the existence of an identitical‐cell epitope in Cry j 1 and Cha o 1.
Dendritic cell–B‐cell interaction: dendritic cells provide B cells with CD40‐independent proliferation signals and CD40‐dependent survival signals
Authors: Wykes M. , Macpherson G.
Published: March 2003

Dendritic cells (DC) have recently been shown to play an important role in B‐cell function. We have previously shown that DC can capture and retain unprocessed antigen in vitro and in vivo, and can transfer this antigen to naive B cells to initiate antigen‐specific antibody responses. We also demonstrated that DC were providing B cells with isotype‐switch signals independent of T cells but that T‐cell help was essential for antibody production. In this study, using B cells and DC from wild type (WT) and CD40 knockout (CD40KO) mice we show that DC initiate proliferation of B cells independently of CD40, because WT or CD40KO DC could induce proliferation of WT or CD40KO B cells, but proliferation was greater in the absence of CD40. DC also provide B cells with survival signals as WT DC improved viability of B cells after a 5‐day culture but survival was reduced in the absence of CD40 expression.
Genes predisposing to autoimmunity augment constitutive major histocompatibility complex class II‐associated presentation of the self‐antigen IgG2abin vivo
Authors: Bartnes K. , Li X. , Iwamoto M. , Izui S. , Hannestad K.
Published: March 2003

The self‐antigen IgG2ab is poorly presented to a γ2ab 435–451‐reactive I‐Ad‐restricted T‐cell hybridoma unless available in high concentrations or targeted to Fcγ‐ or complement receptors. Environmental factors, probably the extent of microbial challenge, profoundly influence the constitutive γ2ab/I‐Ad presentation in IgCHb, H‐2d mice. Here we report also a strong genetic impact. Constitutive presentation was highly efficient in spleen and thymus of (NZB × BXSB)F1 mice, which inherit a predisposition to develop lupus. Presentation correlated with disease progression and the serum levels of IgG2ab and IgG2ab complement factor 3 complexes. The finding that constitutive presentation was by far most efficient in males indicated that it was augmented by the Y chromosome‐linked autoimmune acceleration Yaa gene. In line with previous data for healthy mice, constitutive γ2ab/I‐Ad presentation was most pronounced in the adherent spleen cell fraction and improved by further enrichment for dendritic cells. Notably, however, whereas in normal mice the γ2ab determinant was undetectable on B cells lacking surface IgG2ab, such B cells contributed considerably to constitutive presentation in (NZB × BXSB)F1 hybrids. Presumably this resulted from complement receptor‐mediated internalization of IgG2ab‐containing immune complexes formed in lupus. These data add to the evidence that B cells with self‐reactive receptors, known to exist in the mature repertoire, may present non‐cognate foreign antigen to anti‐foreign helper T lymphocytes and thus differentiate into autoantibody‐secreting cells, and might likewise account for the polyclonal B‐cell activation characteristic of several autoimmune syndromes.
Natural killer 1.1+αβ T cells in the periimplantation uterus
Authors: Dang Y. , Beckers J. , Wang C.‐R. , Heyborne K. D.
Published: March 2003

When the developing embryo implants into the uterine wall, resident maternal immune cells may encounter antigens present on the fetal tissues. The nature and constituents of the ensuing maternal immune response, and its regulation, are of considerable interest in understanding normal and abnormal pregnancy. Here, we report the presence of natural killer (NK)1.1+αβ T cells in the murine periimplantation uterus. These cells account for a large portion of both the T‐cell and natural killer cell populations in early pregnancy, while their numbers in the non‐pregnant uterus and later in pregnancy are greatly reduced. Phenotypically, these NK1.1+αβ T cells belong to a previously described subset of cells that bear a Vα14‐Jα281‐encoded T‐cell receptor. Unlike other organs, where both CD4+ and CD4−/CD8− NK1.1+αβ T cells are found, the placental/decidual population appears to be entirely CD4−/CD8−. The Vβ repertoire of the placental/decidual population is also altered from that of other organs, with a majority of cells expressing Vβ3. Together, these features suggest the possibility of local development. NK1.1+αβ T cells are known to recognize the class I‐like CD1 molecule. Consistent with this association, we demonstrate CD1 expression by tissues within the pregnant uterus. Our findings define an additional organ‐specific immune environment where NK1.1+αβ T cells may play a role, and continue to demonstrate the specialized nature of the maternal intrauterine immune system during pregnancy.
Expression of kininogens in the connective tissue‐type mast cells of the rat
Authors: Hosoi K. , Matsuura S. , Tsumura K. , Wei W. , Parvin M. N. , Tada J. , Akamatsu T. , Kanamori N. , Suzuki K.
Published: March 2003

The connective tissue‐type mast cells present in the submandibular gland (SMG) and peritoneal cavity of rats were found to express kininogens (KGs), the expression of which was demonstrated by Western blotting, reverse transcription–polymerase chain reaction (RT–PCR), RT–PCR Southern blotting, and light‐ and electron‐microscopic immunocytochemistry. In the SMG, the analysis of cDNA amplified by RT–PCR revealed that the molecular species of mRNAs expressed were high‐molecular‐weight (HMW)‐K KG and T‐I KG. Light microscopic immunocytochemistry exclusively localized the KG protein(s) in the mast cells present in the SMG. The signals in the mast cells were very strong, but no positive reaction was observed in the granular convoluted tubular cells, acinar cells or striated duct cells. As determined by using electron microscopy, extremely strong labelling with immunogold was observed in the secretory granules of the mast cells, but no labelling in their nucleus or cytoplasm. Analysis by Western blotting and RT–PCR Southern blotting indicated that both protein and mRNA of KGs were present in the mast cells separated from the peritoneal cavity, indicating de novo synthesis of KG in these cells. Preliminary experiments implied that the connective tissue‐type mast cells in other rat tissues also expressed KG.
The gills are an important site of iNOS expression in rainbow trout Oncorhynchus mykiss after challenge with the Gram‐positive pathogen Renibacterium salmoninarum
Authors: Campos‐perez J. J. , Ward M. , Grabowski P. S. , Ellis A. E. , Secombes C. J.
Published: March 2003

Following injection challenge of rainbow trout with the Gram‐positive pathogen Renibacterium salmoninarum, serum nitrate levels increased indicative of NO production. The timing and amount of nitrate produced varied with the virulence of the bacterial strain used, with the highest levels seen in fish challenged with the most virulent (autoaggregating) strain. Immunization with a killed R. salmoninarum preparation in Freund’s incomplete adjuvant significantly increased nitrate levels after challenge. Inducible nitric oxide synthase (iNOS) transcript expression was detectable in rainbow trout tissues after injection challenge with R. salmoninarum, and its induction in the gills was both quick (between 3 and 6 hr) and relatively prolonged (lasting several days). iNOS expression in the kidney was also seen at a later stage (24 hr) but appeared to switch off relatively rapidly. Bath challenge with R. salmoninarum also induced iNOS expression in gill, and a variable expression in the gut and kidney also occurred. These results highlight the importance of the gills, not only as a point of entry of pathogens but also as a tissue capable of mounting an immune response.
Minor role played by type I tumour necrosis factor receptor in the control of Mycobacterium avium proliferation in infected mice
Authors: Silva R. A. , Gomes M. S. , Appelberg R.
Published: March 2003

Control of mycobacterial growth depends on the concerted activity of different cytokines acting in different stages of the development of innate and adaptive immune responses. Tumour necrosis factor‐α (TNF‐α) has been shown to play a protective role in Mycobacterium avium infections. Here we assessed the growth of this mycobacterial species in wild‐type mice and in mice with a genetically engineered disruption of the type I receptor for TNF‐α (p55‐KO mice). p55‐KO mice infected with a low‐virulence strain of M. avium exhibited a slightly delayed capacity to eliminate the micro‐organisms from the liver as compared with wild‐type animals. However, either the growth of this strain in the other organs studied (spleen and lung) or the growth of two other strains of M. avium with intermediate or high virulence, failed to be affected by mutation of the TNF‐α receptor. p55‐KO mice were also as protected by the administration of recombinant interleukin‐12 as the heterozygous p55 +/– mice. We conclude that signalling through the type I TNF receptor plays a small role in vivo in the induction of mycobacteriostasis during M. avium infection but may improve survival during infection with virulent mycobacteria, independently of the extent of their proliferation.
Soluble L‐selectin levels in type I diabetes mellitus: a surrogate marker fordisease activity?
Authors: Krętowski A. , Gillespie K. M. , Bingley P. J. , Kinalska & I.
Published: March 2003

L‐selectin (CD62L) is a cell adhesion molecule which plays a key role in the initiation of leucocyte migration from blood vessels to sites of local inflammation. The aim of this study was to investigate T‐lymphocyte expression of CD62L antigen and serum levels of soluble L‐selectin (sL‐selectin) in subjects with clinical and preclinical type I diabetes to determine whether they could provide surrogate markers for disease activity. CD62L selectin expression on memory T lymphocytes was studied by cytometric analysis in 22 patients with newly diagnosed type I diabetes, 20 first‐degree relatives of patients with type I diabetes, 14 patients with Graves’ disease, and 22 healthy controls. sL‐selectin levels were measured by enzyme‐linked immunosorbent assay (ELISA) in enlarged groups of subjects in these categories, as well as in patients with long‐standing type I diabetes, treated Graves’ disease and type II (non‐insulin dependent) diabetes. L‐selectin levels were also related to islet autoantibodies, human leucocyte antigen (HLA) genotype and L‐selectin T668C gene polymorphisms. L‐selectin expression on memory T lymphocytes was reduced in newly diagnosed diabetes and islet autoantibody positive siblings compared with controls. sL‐selectin levels were significantly raised in newly diagnosed type I diabetes compared with controls, with intermediate levels in family members, both with and without islet autoantibodies, and in long‐standing type I diabetes. Levels were also raised in patients with untreated Graves’ disease. Patients with type II diabetes had sL‐selectin levels which did not differ from controls. sL‐selectin levels correlated with the presence of diabetes‐associated HLA alleles in both family members and controls; levels also fell with increasing age in family members. Multiple regression analysis showed that HLA genotype and age were independent determinants of sL‐selectin levels. sL‐selectin levels are raised at the time of diagnosis of type I diabetes and Graves’ disease and appear to be modulated by disease activity, but levels are determined predominantly by HLA‐associated genetic susceptibility and age. sL‐selectin may provide a late marker of autoimmune destruction of islets and sequential measurement may be useful in monitoring disease activity and the effect of interventions preceding type I diabetes.
Differential effects of CD4 and CD8 engagement on the development of cytokine profiles of murine CD4+ and CD8+ T lymphocytes
Authors: Campbell S. B. , Komata T. , Kelso A.
Published: March 2003

A simple culture system devoid of antigen‐presenting cells was used to examine the ability of immobilized antibodies to lymphocyte function‐associated antigen‐1 (LFA‐1) (CD11a), CD28 and CD4 or CD8 to modulate the responses of normal murine CD4+ and CD8+ lymph node T cells to immobilized anti‐CD3 antibody and interleukin‐2 (IL‐2). All the antibodies enhanced proliferative responses to limiting anti‐CD3 antibody. Both CD4+ and CD8+ cells produced substantial titres of IL‐3 and interferon‐γ (IFN‐γ) in primary and secondary cultures regardless of the coactivating antibodies used for priming. By contrast, the combination of anti‐CD4 with anti‐CD3 antibody stimulated significantly higher titres of IL‐4 than any other antibody combination in cultures of CD4+ cells. This CD4‐dependent IL‐4 response was induced in CD4+ T cells of naive (CD44low) phenotype and was similar in magnitude to the response induced by exogenous IL‐4 but, unlike the latter, was not associated with elevated IL‐3 synthesis. A comparable effect of anti‐CD8 antibodies on CD8+ cells was not observed: although IL‐4 production by CD8+ cells was induced by exogenous IL‐4, it was not detected following coactivation with anti‐CD8 or any other antibodies. We conclude that anti‐CD4 antibody is a potent inducer of IL‐4‐secreting CD4+ T cells whose effects can be distinguished from those of anti‐CD8 antibody on CD8+ T cells and from those of IL‐4 on either subset.
Functional activity of CD40 antibodies correlates to the position of binding relative to CD154
Authors: Barr T. A. , Heath A. W.
Published: March 2003

In this study we describe the characterization of a panel of 12 anti‐mouse CD40 monoclonal antibodies (mAb). Characterization was performed in terms of antibody‐binding site relative to the CD154 ligand, and the relationship between position and functional outcome of binding. The antibodies divided into three groups. The first were strong inhibitors of CD154 binding, and induced strong proliferative and activation signals to B cells. Two antibodies gave intermediary inhibition and comparable levels of activation. The remaining antibodies were found to bind outside the CD154 binding site and were poor inducers of B‐cell activation. Data presented show a strong correlation between location of mAb binding and the resultant activation signal delivered. This correlation is shown to be independent of the isotype of the antibody involved and of its affinity. Implications of these findings are discussed.
Persistent infection with Listeria monocytogenes in the kidney induces anti‐inflammatory invariant fetal‐type γδ T cells
Authors: Ikebe H. , Yamada H. , Nomoto M. , Takimoto H. , Nakamura T. , Sonoda K.‐H. , Nomoto K.
Published: March 2003

After intraperitoneal inoculation with Listeria monocytogenes, γδ T cells appear in the peritoneal cavity preceding the appearance of αβ T cells. Such γδ T cells predominantly express T‐cell receptor (TCR)Vγ1/Vδ6, develop through an extrathymic pathway, and contribute to host defence against the bacteria. We have observed a gradual increase in γδ T cells in kidneys of mice after intrarenal inoculation with L. monocytogenes, which resulted in an unusually long‐lasting local infection. In this study, we examined the characteristics and the roles of the γδ T cells induced in this model. It was found that these γδ T cells predominantly expressed TCRVγ6/Vδ1 with canonical junctional sequences identical to those expressed on fetal thymocytes. Although depletion of such γδ T cells in vivo did not affect the number of bacteria, it resulted in histologically exacerbated inflammation in the kidneys. These results indicate that a persistent infection with L. monocytogenes in kidneys induces a different kind of γδ T cell from that induced after intraperitoneal infection. The former expresses invariant fetal‐type Vγ6/Vδ1+TCR and plays a regulatory role in resolution of inflammation.
Induction of in vivo resistance to Mycobacterium avium infection by intramuscular injection with DNA encoding interleukin‐18
Authors: Kim S. H. , Cho D. , Kim T. S.
Published: March 2003

Interferon‐gamma (IFN‐γ) is closely associated with the generation of cell‐mediated immunity and resistance to intracellular parasites. Interleukin‐18 (IL‐18) was known to strongly induce IFN‐γ production by T cells and natural killer (NK) cells. In order to determine whether injection with DNA encoding IL‐18 can stimulate the resistance to Mycobacterium avium complex (MAC) infection, the mature IL‐18 cDNA with κ leader sequence was cloned under control of the cytomegalovirus (CMV) promoter (TcCMVIL‐18) and its effect on MAC infection was investigated in genetically susceptible BALB/c mice. Injection with the TcCMVIL‐18 DNA during intranasal infection with MAC resulted in a significant decrease in bacterial load of lung during the entire 8‐week observation period, while injection with the TcCMV control DNA did not. Lung cells in mice injected with the TcCMVIL‐18 DNA showed persistent production of IFN‐γ throughout the 8‐week period. Furthermore, immunization with the TcCMVIL‐18 DNA induced and maintained significantly higher levels of cytotoxic activity and nitric oxide production by lung cells than immunization with the TcCMV control vector. This work suggests that IL‐18 DNA vaccination may be useful in the immunotherapeutic or immunoprotection approaches of infections by intracellular parasites such as mycobacteria.
Systematic characterization of human CD8+ T cells with natural killer cell markers in comparison with natural killer cells and normal CD8+ T cells
Authors: Ohkawa Takashi , Seki Shuhji , Dobashi Hiroshi , Koike Yuji , Habu Yoshiko , Ami Katsunori , Hiraide Hoshio , Sekine Isao
Published: March 2003

We investigated the function of CD56+ CD8+ T cells (CD56+ T cells) and CD56− CD57+ CD8+ T cells (CD57+ T cells; natural killer (NK)‐type T cells) and compared them with those of normal CD56− CD57− CD8+ T cells (CD8+ T cells) and CD56+ NK cells from healthy volunteers. After the stimulation with immobilized anti‐CD3 antibodies, both NK‐type T cells produced much larger amounts of interferon‐γ (IFN‐γ) than CD8+ T cells. Both NK‐type T cells also acquired a more potent cytotoxicity against NK‐sensitive K562 cells than CD8+ T cells while only CD56+ T cells showed a potent cytotoxicity against NK‐resistant Raji cells. After the stimulation with a combination of interleukin (IL)‐2, IL‐12 and IL‐15, the IFN‐γ amounts produced were NK cells ≥ CD56+ T cells ≥ CD57+ T cells > CD8+ T cells. The cytotoxicities against K562 cells were NK cells > CD56+ T cells ≥ CD57+ T cells > CD8+ T cells while cytotoxicities against Raji cells were CD56+ T cells > CD57+ T cells ≥ CD8+ T cells ≥ NK cells. However, the CD3‐stimulated proliferation of both NK‐type T cells was smaller than that of CD8+ T cells partly because NK‐type T cells were susceptible to apoptosis. In addition to NK cells, NK‐type T cells but not CD8+ T cells stimulated with cytokines, expressed cytoplasmic perforin and granzyme B. Furthermore, CD3‐stimulated IFN‐γ production from peripheral blood mononuclear cells (PBMC) correlated with the proportions of CD57+ T cells in PBMC from donors. Our findings suggest that NK‐type T cells play an important role in the T helper 1 responses and the immunological changes associated with ageing.
Influence of CD4 or CD8 deficiency on collagen‐induced arthritis
Authors: Ehinger Magnus , Vestberg Mikael , Johansson Åsa C. M. , Johannesson Martina , Svensson Anders , Holmdahl Rikard
Published: March 2003

The role of T cells in the mouse collagen‐induced arthritis (CIA) model for rheumatoid arthritis is not clarified, and different results have been reported concerning the role of CD4 and CD8 T cells. To address this issue, we have investigated B10.Q mice deficient for CD4 or CD8. The mice lacking CD4 were found to be less susceptible to disease, but not completely resistant, whereas the CD8 deficiency had no significant impact on the disease. No difference in the development of late occurring relapses was noted. Interestingly, the CD4‐deficient mice had a severely reduced response to the glycosylated form of the immunodominant type II collagen (CII) 256–270 peptide whereas the response to the non‐glycosylated peptide was not significantly different. Furthermore, CD4‐deficient mice had lower antibody responses to CII, explaining the lower disease susceptibility. In comparison with previously reported results, it is apparent that the lack of CD4 molecules has a different impact on CIA if present on different genetic backgrounds, findings that could possibly be related to the occurrence of different disease pathways of CIA in different mouse strains.
Bactericidal/permeability‐increasing protein promotes complement activation for neutrophil‐mediated phagocytosis on bacterial surface
Authors: Nishimura H. , Gogami A. , Miyagawa Y. , Nanbo A. , Murakami Y. , Baba T. , Nagasawa S.
Published: March 2003

The neutrophil bactericidal/permeability‐increasing protein (BPI) has both bactericidal and lipopolysaccharide‐neutralizing activities. The present study suggests that BPI also plays an important role in phagocytosis of Escherichia coli by neutrophils through promotion of complement activation on the bacterial surface. Flow cytometric analysis indicated that fluorescein‐labelled E. coli treated with BPI were phagocytosed in the presence of serum at two‐ to five‐fold higher levels than phagocytosis of the bacteria without the treatment. In contrast, phagocytosis of the fluoresceined bacteria with or without treatment by BPI did not occur at all in the absence of serum. The phagocytosis stimulated by BPI and serum was dose‐dependent. The effect of BPI on phagocytosis in the presence of serum was not observed on Gram‐positive bacteria (Staphylococcus aureus). Interestingly, the complement C3b/iC3b fragments were deposited onto the bacterial surface also as a function of the BPI concentration under conditions similar to those for phagocytosis. Furthermore, the BPI‐promoted phagocytosis was blocked completely by anti‐C3 F(ab′)2 and partially by anti‐complement receptor (CR) type 1 and/or anti‐CR type 3. These findings suggest that BPI accelerates complement activation to opsonize bacteria with complement‐derived fragments, leading to stimulation of phagocytosis by neutrophils via CR(s).
Generation of cellular immunity to lymphocytic choriomeningitis virus is independent of CD1d1 expression
Authors: Spence Philip M. , Sriram Venkataraman , Van Kaer Luc , Hobbs Jacqueline A. , Brutkiewicz Randy R.
Published: March 2003

CD1 molecules are cell surface glycoproteins, structurally similar to major histocompatibility complex (MHC) class I molecules. The murine CD1d1 molecule has been shown to be essential for the positive selection of a unique subpopulation of T cells [the natural killer (NK) T cells], as CD1d1‐deficient mice lack NK T cells. These cells have recently been suggested to play an important role in the induction of innate immunity (i.e. NK cells) and the regulation of immune homeostasis. As such, it was asked whether NK T cells were necessary for the generation of cellular immunity to an acute virus infection. In these studies, the Armstrong strain of lymphocytic choriomeningitis virus (LCMV), a classic inducer of NK cells, and its pathogenic variant clone 13 were used. When NK‐cell activity was assessed on day 3 post‐LCMV infection, surprisingly, it was found that CD1d1‐deficient mice could generate NK‐cell activity at wild‐type levels. Likewise, LCMV‐specific cytotoxic T‐lymphocyte (CTL) activity in CD1d1‐deficient mice was indistinguishable from that generated in wild‐type mice. Additionally, viral titres in the spleen (LCMV Armstrong) and blood (LCMV clone 13) of infected CD1d1‐deficient mice were at comparable levels to those found in wild‐type mice, as were virus infection‐induced increases in cell surface H‐2Kb in the spleen. Therefore, these results suggest that the LCMV‐induced generation of NK‐cell and virus‐specific CTL activity, as well as viral clearance, are independent of CD1d1 expression.
Glycolipid targets of CD1‐mediated T‐cell responses
Authors: Moody D. Branch , Besra Gurdyal S.
Published: March 2003

Members of the CD1 family of antigen‐presenting molecules bind and present a variety of mammalian and microbial glycolipids for specific recognition by T cells. CD1 proteins accomplish their antigen‐presenting function by binding the alkyl chains of the antigens within a deep, hydrophobic groove on the membrane distal surface of CD1, making the hydrophilic elements of the antigen available for contact with the variable regions of antigen‐specific T‐cell receptors. Most models of CD1‐restricted T cells function in infectious, neoplastic, or autoimmune diseases and are based on the premise that CD1‐restricted T‐cell responses are initiated by alterations in cellular glycolipid content. Although a growing number of self, altered self and foreign glycolipid antigens have been identified, the cellular mechanisms that could lead to the generation of antigenic glycolipids within cells, or control the presentation of particular classes of altered self or microbial glycolipids in disease states have only recently come under investigation. Here we review the structures of known glycolipid antigens for T cells and discuss how the chemical nature of these antigens, which is quite different from that of peptides, influences their recognition by T cells.
Genetic fusion of human insulin B‐chain to the B‐subunit of cholera toxin enhances in vitro antigen presentation and induction of bystander suppression in vivo
Authors: Sadeghi Hamid , Bregenholt SØren , Wegmann Dale , Petersen Jacob S. , Holmgren Jan , Lebens Michael
Published: March 2003

The pentameric B‐subunit of cholera toxin (CTB) can be used as an efficient mucosal carrier of either immunogenic or tolerogenic T‐cell epitopes. In this study a series of fusions was constructed between the genes encoding CTB and the B‐chain of human insulin (InsB). The resulting fusion proteins were expressed in Escherichia coli and isolated as cytoplasmic inclusion bodies that were then dissolved and assembled in vitro. GM1 enzyme‐linked immunosorbent assay (ELISA), sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) and Western blot analyses showed that the protein construct in which InsB was fused to the C‐terminus of a CTB monomer (CI) assembled into structures that both bound to the receptor GM1 ganglioside and reacted with monoclonal antibodies to CTB and insulin. Fusion of InsB to the N‐terminus of CTB resulted in protein that could not assemble into pentameric CTB. In vitro assays showed that the CI fusion protein was 300‐fold more potent than native insulin at inducing interleukin‐2 (IL‐2) production by an insulin‐specific T‐cell hybridoma. When administered orally, the CI fusion protein induced efficient immunological suppression of ovalbumin‐specific T‐cell responses in mice co‐immunized parenterally with insulin and ovalbumin. These results demonstrate the stability, GM1 receptor‐binding activity and antigenic authenticity of the CI fusion protein as well as its ability to elicit insulin‐specific T‐cell responses in vitro. In addition, we demonstrate that the CI fusion protein induces efficient immunosuppression after oral administration, raising the possibility of using such constructs in the treatment of type‐1 diabetes.
MD41, a novel T helper 0 clone, mediates mast‐cell dependent delayed‐type hypersensitivity in mice
Authors: Torii Ikuko , Morikawa Shigeru , Harada Takayuki
Published: March 2003

In a previous study on mouse, we have shown that delayed‐type hypersensitivity (DTH) could be classified into two types according to MC requirement. The first type of DTH could be elicited by sensitization with methylated human serum albumin (MHSA) in complete Freund's adjuvant (CFA) in both wild type and mast‐cell deficient (W/Wv) mice. The second type could be elicited by MHSA in incomplete Freund's adjuvant (IFA) sensitization in wild type but not W/Wv mice. While the former was related to classic tuberculin (tbc)‐type DTH, the latter appeared to be a novel mast‐cell dependent DTH (MD‐DTH). In order to investigate the mechanism of MD‐DTH, in this study, we generated an effector T‐cell clone (MD41) from lymph node cells of MHSA in IFA‐sensitized mice and analysed its pattern of cytokine production. Our results from cytokine assays show that following antigen stimulation, MD41 cells produce significant amounts of the T helper 1 (Th1) cytokine interferon‐γ (IFN‐γ) as well as the Th2 cytokines interleukin (IL)‐4 and IL‐10. In addition, double staining for IL‐4 and IFN‐γ revealed that MD41 cells produce both Th1‐ and Th2‐type cytokines simultaneously, which suggest that MD41 represents a Th0 clone rather than a mixture of Th1 and Th2 clones. Adoptive transfer of MD41 cells into wild‐type mice resulted in the development of DTH skin reactions similar to those produced by active sensitization, with very similar histological findings. However, DTH skin reactions could not be induced in W/Wv mice unless first reconstituted with normal bone marrow MC (BM‐MC). Therefore, our study suggests that in conjunction with tissue MC, MD41, a less‐polarized MD‐DTH‐derived Th0 clone, is capable of developing murine DTH to the same extent as strongly polarized Th1 cells and mediates MD‐DTH rather than tbc‐type DTH.
Necessity of the stalk region for immunoglobulin E interaction with CD23
Authors: Chen Bing‐Hung , Ma Check , Caven Timothy H. , Chan‐Li Yee , Beavil Andrew , Beavil Rebecca , Gould Hannah , Conrad Daniel H.
Published: March 2003

Previously, a soluble mouse CD23 chimera, composed of an N‐terminal trimeric isoleucine zipper motif (lz) followed by the entire extracellular region (amino acids 48–331) of CD23 (lz‐CD2348−331), was prepared and exhibited strong binding to rodent immunoglobulin E (IgE). In the current study, we report the construction of a similar human chimeric protein (lz‐huCD2345−321), as well as a series of murine chimeric lz‐CD23 mutants with incremental portions of stalk deleted, to further investigate the role of the stalk region in mediating the CD23–IgE interaction. All chimeric proteins were designed such that the predicted heptad structure of the stalk was retained. IgE binding, as determined by the capacity to inhibit 125I‐IgE from binding to FcεRI‐bearing RBL‐2H3 cells, and by surface plasmon‐resonance analysis using an IgE‐coated sensor chip, was unchanged from the original lz chimera and the binding parameters were similar to those of cell‐surface CD23. The minimal murine chimera that retained IgE‐binding activity was lz‐CD23139−331, which still contains 35 amino acids of the stalk region. When the lz motif was linked to CD23 amino acid 157 (or higher), significant IgE‐binding capacity was lost. With human lz‐CD23, as with mouse, deletion of the stalk greatly reduced IgE‐binding ability. In summary, the data support the concept that at least a portion of the stalk region of CD23 plays a crucial role in maintaining high‐affinity/avidity interaction with IgE. The lz‐CD23 constructs represent a possible alternative for both blocking the IgE/FcεRI interaction and inhibiting IgE production by B lymphocytes.
Skewed autoantibody reactivity to the extracellular domain of myelin oligodendrocyte glycoprotein in multiple sclerosis
Authors: Tejada‐Simon Maria V. , Hong Jian , Rivera Victor M. , Zhang Jingwu Z.
Published: March 2003

Myelin oligodendrocyte glycoprotein (MOG) is found to induce both autoreactive T‐cell and antibody responses associated with demyelinating pathology and is implicated in the pathogenesis of multiple sclerosis (MS). In this study, we addressed the potential association of anti‐MOG immune responses with MS by examining, comparatively, both the T‐cell and antibody responses to recombinant MOG fragments in MS patients and healthy subjects. T cells recognizing MOG were detected in MS patients as well as in healthy subjects, and their precursor frequency in the blood was not increased in patients with MS. MOG‐reactive T cells isolated from both MS patients and healthy subjects exhibited a similar cytokine profile, producing interleukin (IL)‐4, IL‐10 and tumour necrosis factor (TNF), but not interferon‐γ (IFN‐γ), and recognized predominantly the extracellular (residues 1–60) and the transmembrane/cytoplasmic (residues 154–218) domains of MOG. In contrast, anti‐MOG antibodies derived from MS patients displayed a skewed reactivity pattern, even though the occurrence and titres of serum anti‐MOG antibodies were only slightly elevated in MS patients. MS‐derived autoantibodies were predominantly directed at the 1–60 region of MOG, while naturally occurring anti‐MOG antibodies derived from healthy individuals reacted selectively to the 154–218 domain. These differences were statistically significant. The findings of this study are consistent with the presence of anti‐MOG antibodies within demyelinating lesions of MS and their role in the induction of demyelinating pathology in animal models. The study has important implications in the understanding of the autoimmune processes in MS.
Functional and Vβ repertoire characterization of human CD8+ T‐cell subsets with natural killer cell markers, CD56+ CD57− T cells, CD56+ CD57+ T cells and CD56− CD57+ T cells
Authors: Takayama Eiji , Koike Yuji , Ohkawa Takashi , Majima Takashi , Fukasawa Masashi , Shinomiya Nariyoshi , Yamaguchi Takanori , Konishi Mieno , Hiraide Hoshio , Tadakuma Takushi , Seki Shuhji
Published: March 2003

We investigated the individual CD8+ populations with natural killer (NK) cell markers (NK‐type T cell); CD56 single positive (CD56)‐T cells, CD56/CD57 double positive (DP)‐T cells and CD57 single positive (CD57)‐T cells in the peripheral blood. All NK‐type T‐cell populations expressed CD122 and intermediate levels of T‐cell receptor (TCR; regular CD8+ T cells are CD122− and express high levels of TCR). The number of both DP‐T cells and CD57‐T cells, but not CD56‐T cells, gradually increased with age. All NK‐type T‐cell populations produced larger amounts of interferon‐γ than did regular CD8+ T cells after stimulation with interleukin (IL)‐2, IL‐12 and IL‐15. However, CD56‐T cells and CD57‐T cells but not DP‐T cells showed a potent antitumour cytotoxity to NK‐sensitive K562 cells, whereas only CD56‐T cells showed a potent cytotoxity to NK‐resistant Raji cells. Furthermore, although NK‐type T cells produced large amounts of soluble Fas‐ligands, their cytotoxic activities appeared to be mediated by the perforin/granzyme pathway. The oligoclonal or pauciclonal expansions of certain VβT cells were found in each NK‐type T‐cell population. The non‐variant CDR3 region(s) for the TCRβ chain(s) showed CD57‐T cells and CD56‐T cells to be derived from distinct origins, while the DP‐T cell population consisted of a mixture of the clones seen in both CD56‐T cells and CD57‐T cells. Our results suggest that CD57‐T cells and CD56‐T cells are functionally and ontogenically different populations while DP‐T cells appear to originate from both CD56‐T cells and CD57‐T cells.
Memory T‐cell competition for bone marrow seeding
Authors: Di Rosa Francesca , Santoni Angela
Published: March 2003

The presence in the bone marrow of memory CD8 T cells is well recognized. However, it is still largely unclear how T‐cell migration from the lymphoid periphery to the bone marrow is regulated. In the present report, we show that antigen‐specific CD4 T cells, as well as antigen‐specific CD8 T cells, localize to the bone marrow of immunized mice, and are sustained there over long periods of time. To investigate the rules governing T‐cell migration to the bone marrow, we generated chimeric mice in which the lymphoid periphery contained two genetically or phenotypically distinct groups of T cells, one of which was identical to the host. We then examined whether a distinct type of T cell had an advantage over the others in the colonization of bone marrow. Our results show that whereas ICAM1 and CD18 molecules are both involved in homing to lymph nodes, neither is crucial for T‐cell bone marrow colonization. We also observed that memory‐phenotype CD44high T cells, but not virgin‐type CD44−/low T cells, preferentially home to the bone marrow upon adoptive transfer to normal young mice, but not to thymectomized old recipients where an existing memory T‐cell pool precludes their free access. Thus, T‐cell colonization of the bone marrow uses distinct molecules from those implicated in lymph node homing, and is regulated both by the properties of the T cell and by the competitive efficacy of other T cells inhabiting the same, saturable niche. This implies that the homing potential of an individual lymphocyte is not merely an intrinsic property of the cell, but rather a property of the lymphoid system taken as a whole.
Process and reality in information systems benefit analysis
Authors: Changchit Chuleeporn , Joshi Kshiti D. , Lederer Albert L.
Published: March 2003

The identification of the potential benefits of a proposed information system project is a very challenging and important task. However, little research describes how this is actually carried out. The objective of this research was to answer the core question: how do organizations identify the expected benefits of proposed IS projects? To accomplish this objective, the authors studied 24 projects by interviewing 20 subjects from 13 organizations. Based on these interviews, a model of the benefit identification process was formulated showing it to be a set of loosely defined, overlapping, iterative activities. The study suggests that, despite great uncertainty about the potential benefits, proposers were compelled to use the benefit identification process to persuade the organization to be committed to the project. This effort to build commitment under great uncertainty may contribute to the overstatement or understatement of expected benefits. The study offers managers an understanding of the process and guidance for carrying it out. It also suggests that future researchers validate the model, use it to help identify best practices and test related hypotheses.
An exploratory study of the value of pretraining end‐user participation
Authors: Shayo Conrad , Olfman Lorne , Teitelroit Ricardo
Published: March 2003

Although software training is widely seen as an essential contributor to the productive use of computers in organizations, research has not focused on identifying the processes through which software trainers assess end users' training requirements. This research draws from self‐regulation theories to examine the impacts of pretraining end‐user participation on the outcomes of software training. Self‐regulation theories aim to explain why individuals behave in a certain manner in an organizational context. Pretraining end‐user participation consists of a pretraining interview designed to learn the needs of the trainee, and to gain insights into a training design that can make learning the target software more relevant to the trainee. The context of the study was a training programme for a database retrieval software package in a medium‐sized manufacturing company. Approximately half the trainees were involved in the pretraining interview process. Trainees also received one of two training approaches, either applications‐based (relevant problem focused) or construct‐based (generic training approach) training. Data were gathered from questionnaires, quizzes and interviews. Although no clear differences were found, the data indicate that pretraining end‐user participation should be considered a potentially effective tool in enhancing training effectiveness. Pretraining end‐user participation is more likely to suggest who will or will not use a software application after formal training, provide a more realistic view of the content and usefulness of the training, and facilitate motivation planning and management. The paper discusses some potential critical success factors for making pretraining end‐user participation more effective.
Ambiguity in IT adaptation: making sense of First Class in a social work setting
Authors: Henfridsson Ola
Published: March 2003

This paper explores how people make sense of the ambiguity caused by newly introduced information technology (IT) in organizations. A better understanding of these sense‐making processes might provide some basis for improving the way in which information technology is adapted in organizations. On the basis of an interpretive case study, the paper identifies how certain attention structures facilitated and restricted the meaningful construction of IT in a particular organizational context – social work. In this context, the previous coincidence of IT introductions with increasing administrative workload had considerable implications for the way in which a communications technology (First Class) was adapted. On a general level, it is concluded that making sense of ambiguity is an important ingredient in successful IT adaptation.
Putting it all in the trunk: incremental software development in the FreeBSD open source project
Authors: Jørgensen Niels
Published: March 2003

Abstract. Software development in the FreeBSD project is incremental in the sense that a stream of contributions, including bugfixes and minor and major new features, go into a single branch in the repository, the development branch (or ‘trunk’), and are required to preserve the software in a working state. This creates a succession of development releases, akin to the practice of frequent releasing argued by Eric S. Raymond in his essay ‘The Cathedral and the Bazaar’ to be the key to the success of Linux and other open source projects. The positive and negative impact of this approach is discussed based on a survey involving 72 project participants. On the positive side, the data indicate that it creates a highly motivating ‘see bug, fix bug, see bug fixed in new release’ life cycle, and helps integrate bugfixing with new development. On the negative side, the data indicates that the highly incremental model does not support the development of complex new features.