bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel mechanism for regulating clonal propagation of mouse ES cells
Authors: Ogawa Kazuya , Matsui Hisanori , Ohtsuka Satoshi , Niwa Hitoshi
Published: May 2004

Self‐renewal and differentiation of embryonic stem (ES) cells are controlled by the combinatorial action of extracellular signals and regulation of gene expression. For characterizing the entire molecular mechanism governing these events, we first established a feeder‐ and serum‐free culture system in which mouse ES cells could propagate in clonal density in keeping with proper pluripotency. Supplementation of peptide hormones such as adrenocorticotropic hormone (ACTH) is required to remove serum, and the key event in this phenomenon may be the inhibition of the adenylyl cyclase (AC) activity, as it replaces the effect of these peptides. Because ES cells themselves produce the same activity, the finding suggests a novel mechanism in which activation of AC restricts clonal propagation of pluripotent stem cells.
The roles of interleukin-18 in collagen-induced arthritis in the BB rat
Authors: YE X J , TANG B , MA Z , KANG A H , MYERS L K , CREMER M A
Published: May 2004

Interleukin (IL)-18 is a member of the IL-1 cytokine family. Its expression is increased in rheumatoid arthritis synovium, and its proinflammatory effects have been demonstrated in experimental models of murine arthritis. Here, we investigate the actions of varying doses of recombinant rat IL-18 (rIL-18) on the course of type II collagen-induced arthritis (CIA) in BB rats, including clinical and immune events, plus splenic cytokine production. Small doses of rIL-18 (10 and 50 µg/rat) administered intraperitoneally (i.p.) increased arthritis incidence and severity (P < 0·01) when a low-potency CII preparation was used for immunization. IgG1 and IgG2a anti-CII antibody levels were significantly greater in rats given 10 and 50 µg rIL-18 doses than controls. rIL-18 significantly increased levels of proinflammatory cytokines [interferon (IFN)-γ, IL-2, tumour necrosis factor (TNF)-α and IL-6] produced by splenocyte cultures. Larger doses of rIL-18 (300 µg/rat) suppressed arthritis and immunity. To ascertain whether the pro-arthritic effects of IL-18 could be attenuated, rats were treated with neutralizing rabbit anti-rIL-18 IgG before immunization with a high-potency CII preparation. When given serially for 3 weeks, the incidence and severity of CIA, in addition to anti-CII IgG2a and splenic IL-6 and IFN-γ production, were all significantly reduced. Similar results were noted when antibody was given twice, just before arthritis onset. These results demonstrate that IL-18 plays an important proinflammatory role in the pathogenesis of CIA which is achieved, in part, by an immunostimulatory action. Neutralizing endogenous IL-18 with antibodies attenuated CIA, CII immunity and cytokine responses. These studies support the use of IL-18 antagonists as treatments for inflammatory arthritis.
Fucoidan derived fromCladosiphon okamuranus Tokidaameliorates murine chronic colitis through the down-regulation of interleukin-6 production on colonic epithelial cells
Authors: MATSUMOTO S , NAGAOKA M , HARA T , KIMURA-TAKAGI I , MISTUYAMA K , UEYAMA S
Published: May 2004

Our previous study indicated that the interleukin (IL)-6/STAT-3 signal was up-regulated in inflammatory bowel disease (IBD) in both humans and animal models. We also discovered phosphorylated STAT-3 in the nucleus of the colonic epithelial cells in IBD mice. Intestinal epithelial cells (IEC) have been shown to secrete IL-6. Therefore, the secretion of IL-6 from IEC may be one of the mechanisms of STAT-3 phosphorylation in IEC during the pathogenesis of IBD, and inhibition of IL-6 production by IEC may be beneficial in preventing IBD. We examined the preventative effect of various types of fucoidans on IL-6 production in a lipopolysaccahride (LPS)-stimulated murine colonic epithelial cells line, CMT-93, in vitro. We also determined in vivo the effect of fucoidans on murine chronic colitis induced with dextran sodium sulphate. Among fucoidans, those from Cladosiphon okamuranus Tokida and Kjellmaniella crassifolia inhibited IL-6 production in CMT-93 cells with the down-regulation of NF-κB nuclear translocation. Analysis of the effect of fucoidan on murine colitis in vivo showed that the disease activity index and myeloperoxidase activity decreased in mice fed Cladosiphon fucoidan, but not Fucus fucoidan. Cytokine profiles in colonic lamina propria indicated that the synthesis of interferon (IFN)-γ and IL-6 decreased and that of IL-10 and transforming growth factor (TGF)-β increased in mice fed Cladosiphon fucoidan, compared with mice fed a standard diet or Fucus fucoidan. The levels of IL-6 mRNA in colonic epithelial cells was lower in colitis-induced Balb/c mice fed Cladosiphon fucoidan than those fed a standard diet. Fucoidan improves murine chronic colitis by down-regulating the synthesis of IL-6 in the colonic epithelial cells. Fucoidan derived from C. o. Tokida may be useful as a dietary substance for the patients with inflammatory bowel disease.
Increase in granzyme B+ lymphocytes and soluble granzyme B in bronchoalveolar lavage of allergen challenged patients with atopic asthma
Authors: BRATKE K , BÖTTCHER B , LEEDER K , SCHMIDT S , KÜPPER M , VIRCHOW J C , LUTTMANN W
Published: May 2004

Asthma has been linked to a chronic, T-cell-mediated bronchial inflammation. Because other T-lymphocyte-mediated, chronic inflammatory disorders have been associated with elevated granzyme B (grB) expression we tested the hypothesis that atopic asthma might be associated with elevated grB levels in the bronchoalveolar compartment. Therefore we performed intracellular grB staining in lymphocytes from bronchoalveolar lavage (BAL) collected 42 h after segmental allergen provocation (SAP) in allergic patients with bronchial asthma. There was a significant increase in CD3+, CD8+, and CD16/56+ lymphocytes expressing grB in BAL 42 h after SAP as compared to saline challenged controls. However, compared to peripheral blood the percentages of these lymphocyte subsets detected as grB+ in BAL remained significantly lower. Measurement of extracellular grB in BAL fluids by a particle immunoassay revealed significantly elevated grB levels in the allergen challenged bronchoalveolar compartment 42 h following SAP in six of the eight patients (range, <1·0–348·1 pg/ml) as compared to saline challenged controls (range, <1·0–70·5 pg/ml). We conclude that total cell numbers of grB+ lymphocyte subsets increase 42 h after SAP in the lower respiratory tract. In addition there is evidence to suggest that grB is released into the airways of asthmatic patients. This suggests a role for grB in the pathophysiological processes following SAP but its definitive role in allergic bronchial asthma needs to be established.
Immunoregulatory defects of Vα24+Vβ11+ NKT cells in development of Wegener's granulomatosis and relapsing polychondritis
Authors: TAKAGI D , IWABUCHI K , IWABUCHI C , NAKAMARU Y , MAGUCHI S , OHWATARI R , FURUTA Y , FUKUDA S , JOYCE S , ONOÉ K
Published: May 2004

The frequency of either CD4–8– (double negative; DN) or CD4+ Vα24+Vβ11+ NKT cells, the expression of CD1d and the binding of CD1d-tetramer loaded with α-galactosylceramide (α-GalCer) to NKT cells were analysed in peripheral blood mononuclear cells (PBMCs) of patients with Wegener's granulomatosis (WG), relapsing polychondritis (RP) and healthy subjects (HS). DN and CD4+ Vα24+Vβ11+ NKT cells as well as CD1d-α-GalCer tetramer-positive NKT cells, were significantly decreased in number in both WG and RP patients compared to those from HS. When cytokine profiles were analysed in these PBMCs upon stimulation with phorbol ester and calcium ionophore, CD4+ T cells from patients with WG and RP exhibited a Th1 bias, whereas CD4+ NKT cells from WG patients in remission showed a Th2 bias. These findings suggest that NKT cells (especially CD4+ NKT cells) play a regulatory role in Th1 autoimmunity in patients with WG and RP. The reduction in NKT cell counts appears to be associated with the low responsiveness to α-GalCer. The dysfunction of NKT cells to recognize ligands such as α-GalCer may also contribute to the defects observed in NKT cells from WG and RP patients.
Recognition of nonpeptide antigens by human Vγ9Vδ2 T cells requires contact with cells of human origin
Authors: GREEN A E , LISSINA A , HUTCHINSON S L , HEWITT R E , TEMPLE B , JAMES D , BOULTER J M , PRICE D A , SEWELL A K
Published: May 2004

It is becoming apparent that γδ T cells form an important part of the adaptive immune response. However, the ligands recognized by γδ T cell receptors (TCRs) and the exact biological function of the cells that express this receptor remain unclear. Numerous studies have shown that the dominant human peripheral blood subset of γδ T cells, which express a Vγ9Vδ2 TCR, can activate in response to low molecular weight nonpeptidic molecules. Some of these components have been purified from bacteria or parasites. We examined the activation of polyclonal γδ T cell lines, clones with Vγ9Vδ2 and Vγ9Vδ1 TCRs, and γδ T cells directly ex vivo in response to multiple phosphate, alkylamine and aminobisphosphonate (nBP) antigens and purified protein derivative from Mycobacterium tuberculosis (PPD). Vγ9Vδ2 T cells were able to respond to multiple small organic molecules of highly variable structure whereas cells expressing a similar Vγ9 chain paired with a Vδ1 chain failed to recognize these antigens. Thus, the TCR δ chain appears to make an important contribution to the recognition of these antigens. The kinetics of responses to alkylphosphate and alkylamine antigens differ from those of responses to the nBP pamidronate. These different classes of antigen are believed to have differed mechanisms of action. Such differences explain why nBPs can be pulsed onto antigen presenting cells (APCs) and still retain their ability to activate γδ T cells while alkylphosphate and alkylamine antigens cannot. We also demonstrate that a substantial proportion of the cells that produce IFNγ directly ex vivo in response to PPD are γδ T cells and that γδ T cell activation requires contact with cells of human origin.
Differential expression of CTLA-4 among T cell subsets
Authors: JAGO C B , YATES J , OLSEN SARAIVA CÂMARA N , LECHLER R I , LOMBARDI G
Published: May 2004

CTLA-4 (CD152), the CD28 homologue, is a costimulatory molecule with negative effects on T cell activation. In addition to its role in the termination of activation, CTLA-4 has been implicated in anergy induction and the function of regulatory cells. As an intracellular molecule, it must first relocate to the cell surface and be ligated, in order to inhibit activation. Although some studies have investigated CTLA-4 expression on CD4+ T cells, evidence is lacking regarding the kinetics of expression, and expression on T cell subpopulations. We have investigated CTLA-4 kinetics on human purified peripheral CD4+, naïve, memory, CD4+CD25–, CD4+CD25+ regulatory T cells, and T cell clones. Intracellular stores of CTLA-4 were shown to be very low in naïve T cells, whilst significant amounts were present in memory T cells and T cell clones. Cell surface CTLA-4 expression was then investigated on CD4+CD45RA+ (naïve), CD4+CD45RO+ (memory), CD4+CD25–, and CD4+CD25+ T cells. CD25 and CD45RO are both expressed by regulatory T cells. On naïve and CD4+CD25– T cells, CTLA-4 expression declined after four hours. In contrast, on memory and CD4+CD25+ T cells, high levels of expression were maintained until at least 48 hours. In addition, significant CTLA-4 expression was observed on T cell clones following anergy induction, indicating the potential involvement of CTLA-4 also in this form of tolerance.
Influence of human T lymphotrophic virus type I on diffuse pan-bronchiolitis
Authors: YAMAMOTO M , MATSUYAMA W , OONAKAHARA K , WATANABE M , HIGASHIMOTO I , KAWABATA M , OSAME M , ARIMURA K
Published: May 2004

Human T lymphotrophic virus type-I (HTLV-I), a human retrovirus, infects CD4+ lymphocytes and is thought to modify their function and a possible association with pulmonary diseases has also been suggested. However, little is known about the influence of HTLV-I on diffuse pan-bronchiolitis (DPB), a chronic inflammatory lung disease with infiltration of lymphocytes and hyperplasia of the bronchus-associated lymphoid tissue. In this study, 35 DPB patients with and without HTLV-I infection were examined. HTLV-I positive DPB patients were likely to have a larger affected area with lower FEV1. The CD3+/CD25+ lymphocyte percentage was significantly higher in the BALF of HTLV-I positive patients than in negative patients. MIP-1α, IP-10 and levels in BALF were also significantly higher in HTLV-I positive patients than in negative patients. The levels of MCP-1 and IL-8 were not significantly different. In HTLV-I positive patients, the MIP-1α and IP-10 levels showed a significant positive correlation with the percentage of CD3+/CD25 lymphocytes. BALF cells of all HTLV-I positive DPB patients showed expression of p40tax mRNA. We suggest that HTLV-I infection may modify DPB pathogenesis via activation of T cells. We also found that the frequency of ATL development in HTLV-I positive DPB patients was significantly higher than in all HTLV-I positive patients (OR = 8·22, 95% CI = 2·61–25·9, P < 0·01). The levels of TGF-β in patients who developed ATL were significantly lower than in patients who did not develop ATL. Sensitivity and specificity were 80% and 85·7%, respectively (cut-off = 20 pg/ml). We also propose that these features should be taken into consideration in the treatment of DPB in HTLV-I infected individuals.
Effects of commonly used immunosuppressants on graft-derived fibroblasts
Authors: JOHNSSON C , GERDIN B , TUFVESON G
Published: May 2004

In acute rejection of transplanted organs intragraft fibroblasts increase their production of hyaluronan. Hyaluronan has strong water binding capacity and an increased tissue content of hyaluronan thus contributes to the development of interstitial oedema. The present study examined the effects of commonly used immunosuppressants (prednisolone, cyclosporin, tacrolimus, mycophenolic acid and sirolimus) on fibroblast proliferation, hyaluronan production and cell surface receptor expression. Fibroblasts isolated from rejecting tissue and from normal, non-transplanted tissue were studied in parallel. All substances investigated, except tacrolimus, were found to affect fibroblasts in one way or another. The most striking effect was the almost total inhibition of fibroblast proliferation in the presence of mycophenolic acid. Cyclosporin reduced the proliferation by about 50% and prednisolone had an inhibiting effect on hyaluronan production (50% reduction). These effects were observed on fibroblasts isolated from rat cardiac allografts undergoing rejection as well as on fibroblasts obtained from normal heart tissue. In contrast, sirolimus was found to stimulate the proliferation of fibroblasts from rejecting tissue (100% increase), but not that of normal fibroblasts. The majority of the fibroblasts expressed the hyaluronan receptor CD44, with a more intense expression in cultures of fibroblasts derived at rejection. None of the immunosuppressants affected the staining pattern (number of positive cells or intensity). The inhibitory effects of prednisolone, cyclosporin and mycophenolic acid on fibroblasts may contribute to the overall beneficial effects of these drugs when used for prevention or treatment of rejection.
Differential gene expression in mononuclear phagocytes infected with pathogenic and non-pathogenic mycobacteria
Authors: MCGARVEY J A , WAGNER D , BERMUDEZ L E
Published: May 2004

The pathogenic mycobacteria are an insidious group of bacterial pathogens that cause the deaths of millions of people every year. One of the reasons these pathogens are so successful is that they are able to invade and replicate within host macrophages, one of the first lines of defence against intruding pathogens. In contrast, non-pathogenic mycobacteria, such as Mycobacterium smegmatis are killed rapidly by macrophages. In order to understand better the series of events that allow pathogenic mycobacteria to survive and replicate within macrophages, while the non-pathogenic mycobacteria are killed rapidly, we inoculated the human monocytic cell line U937 with pathogenic (M. tuberculosis and M. avium) and non-pathogenic (M. smegmatis) mycobacteria and monitored the expression of over 3500 genes at 4, 12 and 24 h post-inoculation using a commercially available gene array system. We observed multiple differences in the gene expression patterns of monocytes infected with pathogenic and non-pathogenic mycobacteria including genes involved in cytokine, lymphokine and chemokine production, adhesion, apoptosis, signal transduction, transcription, protein cleavage, actin polymerization and growth. We also observed differences in gene expression profiles in monocytes infected with M. tuberculosis or M. avium, indicating that there are differences in the host pathogen interactions of mononuclear phagocytes infected with different pathogenic mycobacterial species. These results increase the understanding of the mechanisms used by pathogenic mycobacteria to cause disease, the host response to these organisms, and provide new insights for antimycobacterial intervention strategies.
Ectopic expression of CCL19 impairs alloimmune response in mice
Authors: Krautwald Stefan , Ziegler Ekkehard , Förster Reinhold , Ohl Lars , Amann Kerstin , Kunzendorf Ulrich
Published: May 2004

Initiation of an antitumour immune response is characterized by a complex process of chemokine‐mediated cell migration and cell–cell interactions. Overexpression of chemokine CCL19 in tumour cells has been shown to result in accelerated tumour rejection under certain experimental conditions, suggesting a novel approach in the therapy of neoplastic malignancies. To investigate CCL19‐mediated modulations of cellular immune responses in vivo, we generated a chimeric CCL19‐immunoglobulin G2b (IgG2b) Fc fusion protein, which binds to the chemokine receptor CCR7 comparable to native CCL19. CCL19‐IgG2b possesses a long‐lasting potent chemotactic activity as a result of the extended half‐life of Fc fusion proteins. Stable overexpression of CCL19‐IgG2b in BALB/c‐derived J558L tumour cells fails to support tumour cell rejection following transplantation in syngeneic mice. Moreover, overexpression of CCL19‐IgG2b hinders tumour rejection in allogeneic C57BL/6 mice. This phenomenon was accompanied by a six‐fold increase of dendritic cells (DCs) isolated from CCL19‐IgG2b‐secreting tumours when compared to the number of DCs isolated from control parental J558L tumours. While mice bearing the allogeneic parental tumour showed an intense hypercellularity in the draining lymph nodes, no such response could be observed in the draining lymph nodes of mice carrying the CCL19‐IgG2b‐secreting tumour. We could demonstrate that overexpression of CCL19‐IgG2b in tumour cells retains antigen‐presenting cells in the tumour mass and prevents DCs from migrating into draining lymph nodes to present antigens and to activate T cells, resulting in an impaired immune response against the tumour.
Aberration of CCR7+ CD8+ memory T cells from patients with systemic lupus erythematosus: an inducer of T helper type 2 bias of CD4+ T cells
Authors: Sen Yang , Chunsong Hu , Baojun Huang , Linjie Zhang , Qun Li , San Jiang , Qiuping Zhang , Junyan Liu , Zhang Xuejun , Jinquan Tan
Published: May 2004

Chemokine receptors are important in the entry of leucocytes into the inflammatory sites of systemic lupus erythematosus (SLE). CCR7+ and CCR7– memory T cells exert different functions in homing, cytokine production and cytotoxicity. To determine whether differential expression and functions of the CCR7 occur in SLE patients, we examined CCR3, CCR4, CCR5, CCR7 and CCR9 on CD4+ and CD8+ T cells from normal and SLE subjects. Flow cytometry, real‐time quantitative reverse transcription polymerase chain reactions and Northern blotting were used to detect the expression of chemokine receptors and cytokines; a chemotaxis assay was used to detect their functions. CD4+ T‐cell stimulation with syngeneic CCR7+ CD8+ CD45RO+ T cells and dendritic cells (including transwell chambers) was used to induce cytokine expression. We demonstrated that CCR7 was selectively, frequently and functionally expressed on CD8+ (94·8%) but not on CD4+ (16·1%) T cells from patients with active SLE, whereas this phenomenon was not seen in normal subjects and in those whose SLE was inactive. CCR7+ CD8+ CD45RO+ memory T cells from patients with active SLE, themselves T helper type 2 (Th2) biased, were inducers of Th2 bias in CD4+ T cells in a cell–cell contact manner in vitro, meanwhile, the cells from both normal subjects and those whose SLE was inactive drove CD4+ T cells into a regulatory T‐cell‐derived cytokine pattern. Our findings might provide new clues to understanding the functions of CCR7+ CD8+ CD45RO+‘central’ memory T cells in autoimmue diseases (such as SLE). We suggest that in the case of active SLE, CCR7+ central memory T cells were able to enter peripheral blood and inflammatory sites from secondary lymphoid organs, were continuously expressing CCR7, and interacted with dendritic cells and functioned as CCR7–‘effector’ memory T cells, which were described in normal humans.
Irradiation up‐regulates CD80 expression through two different mechanisms in spleen B cells, B lymphoma cells, and dendritic cells
Authors: Torihata Hideko , Ishikawa Fumio , Okada Yayoi , Tanaka Yuriko , Uchida Tetsuya , Suguro Toru , Kakiuchi Terutaka
Published: May 2004

We have previously demonstrated irradiation‐induced up‐regulation of CD80 expression in A20‐HL B lymphoma cells by inducing expression of tumour necrosis factor‐α (TNF‐α) and CD154. In the present study, we investigated whether irradiation also up‐regulates CD80 expression in mouse spleen B cells. Because freshly prepared spleen B cells are highly sensitive to irradiation, we employed spleen B cells stimulated with lipopolysaccharide (LPS‐B cells). X‐irradiation (8 Gy) followed by incubation (9–12 hr) highly and selectively up‐regulated CD80 expression in LPS‐B cells, whereas the same treatment slightly increased expression of CD54 and did not affect expression of CD86, major histocompatibility complex class II, CD11a or surface immunoglobulin M. The irradiation‐induced up‐regulation of CD80 expression resulted in enhanced APC function of LPS‐B cells. Up‐regulation of CD80 expression on LPS‐B cells was accompanied by an increase in CD80 mRNA accumulation and nuclear factor (NF)‐κB activation. Activation of NF‐κB was shown to be critical for up‐regulation of CD80 expression as pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF‐κB, severely decreased the observed up‐regulation. X‐irradiation of LPS‐B cells induced expression of TNF‐α but not CD154. However, anti‐TNF‐α monoclonal antibody (mAb) with anti‐CD154 mAb did not inhibit X‐irradiation‐induced up‐regulation of CD80 expression in LPS‐B cells, whereas these mAbs almost completely inhibited this up‐regulation in A20‐HL cells and bone marrow‐derived dendritic cells (DCs). In contrast, a thiol antioxidant, N‐acetyl‐l‐cysteine, completely blocked X‐irradiation‐induced up‐regulation of CD80 expression in LPS‐B cells, but not in A20‐HL cells or in DCs. Based on these findings, we concluded that X‐irradiation up‐regulates CD80 expression not only in A20‐HL cells and DCs but also in LPS‐B cells, and that this up‐regulation in LPS‐B cells via NF‐κB activation is dependent on the generation of reactive oxygen species, while that in A20‐HL cells and DCs is not.
Selective killing of B‐cell hybridomas targeting proteinase 3, Wegener's autoantigen
Authors: Reiners Katrin S. , Hansen Hinrich P. , Krüssmann Anne , Schön Gisela , Csernok Elena , Gross Wolfgang L. , Engert Andreas , Von Strandmann Elke Pogge
Published: May 2004

Wegener's granulomatosis (WG) is a rare disease characterized by granulomatous lesions, small vessel vasculitis and the presence of anti‐neutrophil cytoplasmic autoantibodies (C‐ANCAs) in the sera of affected patients. Their main target antigen is proteinase 3 (PR3), a neutrophil and monocyte‐derived neutral serine protease. Since the standard treatment of this severe autoimmune disease, with cyclophosphamide and corticosteroids, is associated with potential side‐effects, the development of a more specific immunotherapeutic agent is warranted. The key role of ANCA in the pathogenesis of vasculitis and the effectiveness of anti‐CD20 antibodies in patients with refractory WG points towards the importance of B cells in WG. We thus evaluated a new approach to selectively eliminate PR3‐specific autoreactive B cells by targeting the B‐cell receptor. For this purpose we used a bifunctional recombinant fusion protein consisting of the antigen PR3 and a toxin. The cytotoxic component of this novel fusion protein was the ribonuclease angiogenin, a human toxin with low immunogenicity. The toxin was stabilized by exchanging the catalytically relevant histidine in position 44 with glutamine to eliminate the autoproteolytic activity. PR3H44Q was fused either to the N terminus or to the C terminus of angiogenin. The recombinant proteins were expressed in 293T cells. Binding assays demonstrated the appropriate size and recognition by anti‐PR3 antibodies. Using TUNEL technology, we demonstrated that these autoantigen toxins kill proteinase 3‐specific B‐cell hybridomas selectively by inducing apoptosis. The data indicate that autoantigen‐toxins are promising tools in the treatment or co‐treatment of autoimmune diseases in which the antigen is known.
Semen activates the female immune response during early pregnancy in mice
Authors: Johansson Martina , Bromfield John J. , Jasper Melinda J. , Robertson Sarah A.
Published: May 2004

Insemination elicits inflammatory changes in female reproductive tissues, but whether this results in immunological priming to paternal antigens or influences pregnancy outcome is not clear. We have evaluated indices of lymphocyte activation in lymph nodes draining the uterus following allogeneic mating in mice and have investigated the significance of sperm and plasma constituents of semen in the response. At 4 days after mating, there was a 1ḃ7‐fold increase in the cellularity of the para‐aortic lymph node (PALN) compared with virgin controls. PALN lymphocytes were principally T and B lymphocytes, with smaller populations of CD3+ B220lo, NK1.1+ CD3– (NK) and NK1.1+ CD3+ (NKT) cells. CD69 expression indicative of activation was increased after mating and was most evident in CD3+ and NK1.1+ cells. Synthesis of cytokines including interleukin‐2, interleukin‐4 and interferon‐γ was elevated in CD3+ PALN cells after exposure to semen, as assessed by intracellular cytokine fluorescence‐activated cell sorting, immunohistochemistry and quantitative reverse transcriptase polymerase chain reaction. Matings with vasectomized males indicated that the lymphocyte activation occurs independently of sperm. However, in contrast, males from which seminal vesicle glands were surgically removed failed to stimulate PALN cell proliferation or cytokine synthesis. Adoptive transfer experiments using radiolabelled lymphocytes from mated mice showed that lymphocytes activated at insemination home to embryo implantation sites in the uterus as well as other mucosal tissues and lymph nodes. These findings indicate that activation and expansion of female lymphocyte populations occurs after mating, and is triggered by constituents of seminal plasma derived from the seminal vesicle glands. Moreover, lymphocytes activated at insemination may help mediate maternal tolerance of the conceptus in the implantation site.
Contribution of αβ and γδ T cells to the generation of primary immunoglobulin G‐driven autoimmune response in immunoglobulin‐µ‐deficient/lpr mice
Authors: Seagal Jane , Melamed Doron
Published: May 2004

Class switch recombination (CSR) is a T‐cell‐dependent mechanism regulating isotype switching in activated mature B cells. Recently we showed that T‐cell‐independent CSRs occur spontaneously during B lymphopoiesis, but such cells are negatively selected by Fas signalling. In immunoglobulin µ‐deficient mice, lack of Fas rescues isotype‐switched B cells, resulting in generation of an autoimmune primary immunoglobulin G (IgG) repertoire in µMT/lpr mice. In the present study, we studied the role of αβ and γδ T cells in regulating this primary γH‐driven repertoire. We found that a lack of αβ T cells significantly inhibited IgG production and autoimmunity in µMT/lpr mice, whereas a lack of γδ T cells resulted in augmented IgG production and autoimmunity. Also, a lack of T cells in µMT mice rescued isotype‐switched B cells and serum IgG, probably owing to the lack of available FasL. We suggest that although CSRs in B‐cell lymphopoiesis are T‐cell independent, αβ T cells are important in the expansion of isotype‐switched B‐cell precursors and in promoting γH‐driven autoimmunity, whereas γδ T cells regulate these cells.
Interleukin‐21 is a T‐helper cytokine that regulates humoral immunity and cell‐mediated anti‐tumour responses
Authors: Sivakumar Pallavur V. , Foster Donald C. , Clegg Christopher H.
Published: May 2004

Cytokines and their receptors represent key targets for therapeutic intervention. Ligands are being used to supplement cell numbers that become depleted as a result of disease (organ failure, infection) or subsequent disease treatments (i.e. chemotherapy). Conversely, the inhibition of target cell binding by cytokines is an established strategy for abrogating pathologic cellular activities common to many immunological diseases. Considerable effort in biomedical research is being focused on the cytokine families that play a dominant role in regulating immunity and then prioritizing each member for its therapeutic potential. Currently, the interleukin‐2 (IL‐2) family of cytokines is widely recognized for its central involvement in controlling lymphocyte function and is the most explored for medical utility. Collectively, these proteins (or their antagonists) are either marketed drugs or have received advanced testing for an impressive array of indications including cancer, infectious disease, transplantation, inflammation and allergic asthma. Here we review the current understanding of IL‐21, the most recent member of this cytokine family to be discovered. As will be discussed, IL‐21 shares many of the same attributes as its relatives in that it has broad immunoregulatory activity and can modulate both humoral and cell‐mediated responses. Its ability to stimulate durable anti‐tumour responses in mice defines one therapeutic indication that merits clinical development.
Prevention of postmenopausal osteoporosis with pharmacological therapy: practice and possibilities
Authors: Reginster J.‐Y.
Published: May 2004

Postmenopausal osteoporosis (PMO) is a common disease that will become more prevalent in the future, with costly implications for public health. Prevention of the disease and its consequences, namely fractures, is therefore, important for both the individual and society. This review discusses: the goals of PMO prevention; the identification of women at risk, including the use of bone mineral density and bone turnover markers; the relevance in the prevention setting of various current guidelines for PMO management; recent data on therapeutic options for the treatment and prevention of PMO, in particular bisphosphonates, hormone replacement therapy and several other new pharmacological agents. It concludes that it is crucial for PMO prevention to start before disease onset and that, in the light of recent evidence, the existing guidelines need updating if they are to continue to be relevant.
Coffee consumption, type 2 diabetes and impaired glucose tolerance in Swedish men and women
Authors: Agardh E. E. , Carlsson S. , Ahlbom A. , Efendic S. , Grill V. , Hammar N. , Hilding A. , Östenson C.‐G.
Published: May 2004

Objectives.  The association between coffee consumption, type 2 diabetes and impaired glucose tolerance was examined. In addition, indicators of insulin sensitivity and β‐cell function according to homeostasis model assessment were studied in relation to coffee consumption.

Design.  Population‐based cross‐sectional study.

Setting and subjects.  The study comprised 7949 healthy Swedish subjects aged 35–56 years residing within five municipalities of Stockholm. An oral glucose tolerance test identified 55 men and 52 women with previously undiagnosed type 2 diabetes and 172 men and 167 women with impaired glucose tolerance. Information about coffee consumption and other factors was obtained by questionnaire.

Results.  The relative risks (adjusted for potential confounders) of type 2 diabetes and impaired glucose tolerance when drinking ≥5 cups of coffee per day compared with ≤2 cups per day in men were 0.45 [95% confidence intervals (CI) 0.22–0.92] and 0.63 (CI: 0.41–0.97), respectively, and in women 0.27 (CI: 0.11–0.66) and 0.47 (CI: 0.29–0.76) respectively. In subjects with type 2 diabetes and impaired glucose tolerance, high coffee consumption (≥5 cups day−1) was inversely associated with insulin resistance. In addition, in those with type 2 diabetes and in women (not in men) with impaired glucose tolerance high coffee consumption was inversely associated with low β‐cell function. In women, but not obviously in men, with normal glucose tolerance, coffee consumption was associated with a reduced risk of insulin resistance.

Conclusions.  The results of this study indicated that high consumers of coffee have a reduced risk of type 2 diabetes and impaired glucose tolerance. The beneficial effects may involve both improved insulin sensitivity and enhanced insulin response.
IgE antibodies of fish allergic patients cross‐react with frog parvalbumin
Authors: Hilger C. , Thill L. , Grigioni F. , Lehners C. , Falagiani P. , Ferrara A. , Romano C. , Stevens W. , Hentges F.
Published: May 2004

Background:  The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross‐recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin α has been found to be responsible for a case of IgE‐mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross‐react with frog parvalbumin and to appreciate its clinical relevance.

Methods:  The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE‐immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin α and β from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca2+ depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross‐reactive pattern.

Results:  Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with α parvalbumin and 11 of 12 reacted with β parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin.

Conclusion:  Cod parvalbumin, a major cross‐reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross‐reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross‐reactive allergens.
Concentrations of domestic mite and pet allergens and endotoxin in Palestine
Authors: El Sharif N. , Douwes J. , Hoet P. H. M. , Doekes G. , Nemery B.
Published: May 2004

Background:  A few studies have compared indoor allergens and endotoxin levels between urban and rural settings as important determinants for asthma and atopy in children. However, no study was done in the Middle East or investigated refugee camps.

Methods:  As part of a nested case–control study in Ramallah in 2001, we measured house dust mite and pet allergens, as well as endotoxin in dust collected from 110 children's mattresses and living room floors.

Results:  Geometric mean (GM) concentrations of Dermatophagoides pteronyssinus (Der p1) antigen were 4.48 μg/g in mattress dust and 1.23 μg/g floor dust. The highest Der p1 levels were seen in refugee camps. Concentrations of Dermatophagoides farinae antigen (Der f1) were much lower (<0.08 μg/g dust). Concentrations of cat allergen (Fel d1) were highest in villages, and those of dog allergen (Can f1) were highest in mattresses from cities and in floor dust from refugee camps. GM of endotoxin levels were 25.7 EU/mg in mattress dust and 49 EU/mg dust in floor dust.

Conclusions:  Concentrations of Der p1 were high compared to Western European countries, but were lower compared to UK and Australia. Levels of pet allergens were lower than in Western Europe. Endotoxin levels were higher compared to developed countries. Indoor environmental factors such as dampness seemed to be important determinants for allergen and endotoxin, but living habits such as lack of mattress cover appeared unimportant.
Cytotoxic mechanisms in different forms of T‐cell‐mediated drug allergies
Authors: Kuechler P. C. , Britschgi M. , Schmid S. , Hari Y. , Grabscheid B. , Pichler W. J.
Published: May 2004

Background:  Cytotoxic mechanisms are involved in different forms of drug induced exanthems.

Methods:  Here we compare the killing pathways of CD4+, CD8+ and CD4/CD8+ T‐cell lines (TCL) and clones derived from patients suffering from maculopapular, bullous and pustular drug eruptions. In vitro, perforin and Fas‐mediated killing was analysed in cytotoxicity assays against autologous Epstein–Barr virus (EBV)‐transformed B‐cell lines, Fas‐transfected mouse lymphoblasts and natural killer (NK)‐target cells. In addition, affected skin lesions and the TCL and clones were stained for perforin and FasL‐expression.

Results:  We detected perforin and some FasL‐mediated killing in all three types of exanthems. Some of the drug‐specific T‐cell clones analysed exerted mainly perforin‐, other more FasL‐mediated killing showing no strict relationship between their perforin‐ and Fas‐mediated cytotoxic capacity. Using a cell culture method focusing on the generation of cytotoxic T cells, we detected drug‐specific CD8+, TCRαβ+ T cells, which failed to proliferate to drug presentation by antigen presenting cells but killed in a drug dependent way. Interestingly, these cells had substantial natural killer‐like T cell(s) like features as they were CD56+ and CD94+ and had the ability to kill the NK‐sensitive cell line K562.

Conclusion:  Our data underline the important role of cytotoxic mechanisms in different forms of drug induced exanthems and suggest that even some T cells with NK‐like characteristics may be involved in drug hypersensitivity.
The influence of air conditioning, humidity, temperature and other household characteristics on mite allergen concentrations in the northeastern United States
Authors: Van Strien R. T. , Gehring U. , Belanger K. , Triche E. , Gent J. , Bracken M. B. , Leaderer B. P.
Published: May 2004

Background:  Information about the influence of housing and occupant characteristics on mite allergen concentrations is crucial to determine which methods could be used to decrease exposure of susceptible subjects.

Objectives:  To identify housing and occupant characteristics that are associated with mite allergen concentrations in house dust collected from living rooms and mattresses.

Methods:  We collected dust samples from 750 homes in the northeastern US. The influence of various characteristics on concentrations of mite allergens (Der p 1 and Der f 1) was studied using multiple linear regression analysis.

Results:  Some characteristics, like absence of air conditioners, the presence of mold or mildew, and a lower temperature were consistently associated with higher concentrations of both mite allergens in dust from all sampling locations. However, none of these factors changed Der p 1 or Der f 1 concentrations by more than a factor of 2. People of white ethnic background had roughly two times higher mite allergen concentrations, while family income, family size, and education level only marginally influenced mite allergen concentrations.

Conclusions:  Various housing characteristics have some influence on mite allergen concentrations, and could possibly be used to decrease exposure of susceptible subjects. However, only a limited percentage of the variation in mite allergen concentrations was explained by these characteristics.
Eosinophils and atopic dermatitis
Authors: Simon D. , Braathen L. R. , Simon H.‐U.
Published: May 2004

In spite of the progress regarding the description of immunological phenomena associated with atopic dermatitis (AD), the pathogenesis of this disease still remains unclear. The presence of eosinophils in the inflammatory infiltrate of AD has long been established. Eosinophil numbers as well as eosinophil granule protein levels in peripheral blood are elevated in most AD patients and appear to correlate with disease activity. Moreover, eosinophil granule proteins, which possess cytotoxic activity, are deposited in the skin lesions. These observations indicate a role of eosinophils in the pathogenesis of AD. Furthermore, AD is associated with increased production of T helper 2 cytokines including interleukin (IL)‐5, which specifically acts on eosinophils, resulting in accelerated eosinophilopoiesis, chemotaxis, cell activation, and delayed apoptosis. Therefore, IL‐5 is an interesting target for experimental therapy in this inflammatory disorder of the skin. Such studies might result in new insights into the pathogenetic role of eosinophils in AD.
Specific immunotherapy in honeybee venom allergy: a comparative study using aqueous and aluminium hydroxide adsorbed preparations
Authors: Ruëff F. , Wolf H. , Schnitker J. , Ring J. , Przybilla B.
Published: May 2004

Background:  For the immunotherapy of Hymenoptera venom allergy various preparations and treatment protocols are in use. However, controlled studies making direct comparisons of the efficacy and safety of different regimens are rare.

Objective:  To assess prospectively different venom immunotherapy (VIT) protocols using an aqueous or an aluminium hydroxide adsorbed allergen preparation for the treatment of honeybee venom (HBV) allergy.

Methods:  Sixty‐five HBV allergic patients (42 males, 23 females; aged 17–75 years) with a history of systemic anaphylactic reactions (SARs) to honeybee stings were treated according to three different regimens. During the incremental phase, patients in group A (n = 21) or B (n = 21) received an aqueous preparation according to a rush protocol. Patients in group C (n = 23) were treated with conventional (‘slow’) VIT using an aluminium hydroxide adsorbed depot preparation. The maintenance dose was 100 μg venom in all groups. Maintenance treatment in group A was performed with the aqueous preparation administered every 4 weeks, whereas in groups B and C the depot preparation was administered every 8 weeks (group B) or every 4 weeks (group C). A sting challenge test with a living honeybee was performed in 49 patients, 6–12 months after reaching the maintenance dose. Another seven patients were stung accidentally by a honeybee (‘field sting’).

Results:  Treatment with the aqueous preparation evoked large local reactions more frequently than the depot preparation in the dose increase phase [53/693 (7.6%) vs 8/206 (3.9%); P = 0.059] and also in the course of maintenance therapy [85/172 (49.4%) vs 58/478 (12.1%); P < 0.001]. During the dose increase phase, systemic side‐effects seemed to occur more frequently in patients on rush VIT with the aqueous preparation compared to patients initially treated with the conventional schedule using the depot preparation [13/42 (31.0%) vs 3/23 (13.0%); not significant). When re‐stung by the culprit insect, SARs were observed in 3/20 patients (15.0%) in group A, 2/18 (11.1%) in group B and 3/18 (16.7%) in group C (not significant).

Conclusions:  The aluminium hydroxide adsorbed HBV preparation caused fewer large local reactions than the aqueous preparation. The therapeutic efficacy of the three treatment protocols did not differ.
Effects of NaCl on water relations and cell wall elasticity and composition of red‐osier dogwood (Cornus stolonifera) seedlings
Authors: Mustard Jennifer , Renault Sylvie
Published: May 2004

Red‐osier dogwood (Cornus stolonifera Michx, Syn. Cornus sericea), a species relatively well adapted to moderately saline conditions compared with other boreal species, was used to test the effects of NaCl on plant water relations, cell wall elasticity, and cell wall composition of seedlings. Three month‐old seedlings were treated hydroponically with 0, 25, and 50 mm NaCl for 21 days. The osmotic potential at full turgor, osmotic potential at turgor loss, pressure potential at full turgor, and relative water content at turgor loss of red‐osier dogwood shoot tissue were not significantly affected by the NaCl treatments. Cell wall elasticity of the shoot tissues did not change following NaCl treatments, suggesting that elastic adjustment did not play a role in the adaptation mechanism. Hemicellulose content of the cell wall increased in salt treated seedlings. The primary sugar found in the cell wall hemicellulose fraction was xylose. In the pectin fraction arabinose and galacturonic acid were the main sugars. Sodium chloride stress did not alter the sugar composition of the hemicellulose fraction; however, NaCl did increase the amount of rhamnose in the pectin fraction. The results of this study suggest that at moderate salinity red‐osier dogwood does not make any osmotic or elastic adjustments in the shoot tissue, but some changes in the cell wall composition do occur. These changes could contribute to the decrease in growth recorded in red‐osier dogwood during NaCl stress.
Role of basipetal auxin transport and lateral auxin movement in rooting and growth of etiolated lupin hypocotyls
Authors: López Nicolás Juana Inés , Acosta Manuel , Sánchez‐Bravo José
Published: May 2004

The involvement of polar auxin transport (PAT) on the growth of light‐grown seedlings and rooting is generally accepted, while the role of auxin and PAT on the growth of dark‐grown seedlings is subject to controversy. To further investigate this question, we have firstly studied the influence of NPA, a known inhibitor of PAT, on the rooting and growth of etiolated Lupinus albus hypocotyls. Rooting was inhibited when the basal ends of de‐rooted seedlings were immersed in 100 µm NPA but was partially restored after immersion in NPA + auxin. However, NPA applied to de‐rooted seedlings or the roots of intact seedlings did not inhibit hypocotyl growth. It was taken up and distributed along the organ, and actually inhibited the basipetal transport of (3H)‐IAA applied to isolated hypocotyl sections. Since the apex is the presumed auxin source for hypocotyl growth and rooting, and the epidermis is considered the limiting factor in auxin‐induced growth, the basipetal and lateral auxin movement (LAM) after application of (3H)‐IAA to decapitated seedlings were studied, in an attempt to evaluate the role of PAT and LAM in the provision of auxin to competent cells for growth and rooting. Local application of (3H)‐IAA to the stele led to the basipetal transport of auxin in this tissue, but the process was drastically reduced when roots were immersed in NPA since no radioactivity was detected below the apical elongation region of the hypocotyl. LAM from the stele to the cortex and the epidermis occurred during basipetal transport, since radioactivity in these tissues increased as transport time progressed. Radioactivity on a per FW basis in the epidermis was 2–4 times higher than in the cortex, which suggests that epidermal cells acted as a sink for LAM. NPA did not inhibit LAM along the elongation region. These results suggest that while PAT was essential for rooting, LAM from the PAT pathway to the auxin‐sensitive epidermal cells could play a key role in supplying auxin for hypocotyl elongation in etiolated lupin seedlings.