bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological function of CD40 on human endothelial cells: costimulation with CD40 ligand and interleukin‐4 selectively induces expression of vascular cell adhesion molecule‐1 and P‐selectin resulting in preferential adhesion of lymphocytes
Authors: Kotowicz K. , Dixon G. L. J. , Klein N. J. , Peters M. J. , Callard R. E. 
Published: March 2003

SummaryThe expression of adhesion molecules on vascular endothelial cells determines the pattern of migration and extravasation of leucocytes in inflammation and immunity. Here we show that costimulation with CD40 ligand (CD40L) and interleukin (IL)‐4 (or IL‐13) gives rise to a unique pattern of adhesion molecule expression by human umbilical vein endothelial cells (HUVEC). CD40 ligation alone enhanced expression of vascular cell adhesion molecule‐1 (VCAM‐1), intracellular adhesion molecule‐1 (ICAM‐1) and E‐selectin whereas IL‐4 and IL‐13 increased expression of VCAM‐1 and P‐selectin but not ICAM‐1 or E‐selectin. When IL‐4 and CD40L were combined there was an additional increase of both VCAM‐1 and P‐selectin, but ICAM‐1 and E‐selectin were both inhibited. The combined effects of IL‐4 and CD40L signalling were not the result of altered response kinetics, enhanced sensitivity of the endothelium, or increased expression of CD40 or the IL‐4 receptor. The rise in VCAM‐1 expression induced by combined IL‐4 and CD40L stimulation was slower and more sustained than with tumour necrosis factor‐α (TNF‐α) and occurred only on a subset (75–80%) of the endothelial cell population compared to 100% with TNF‐α. Costimulation with IL‐4 and CD40L increased adhesion of T cells and B cells above levels obtained with either signal alone, but decreased adhesion of neutrophils. Furthermore, CD40 and IL‐4 synergistically increased IL‐6 but decreased IL‐8 production by HUVEC. These results show that interactions between IL‐4 and CD40 on endothelial cells give rise to specific patterns of adhesion molecule expression and cytokine production that may have important implications for lymphocyte and neutrophil migration and function at sites of inflammation.
Xenogeneic islet re‐transplantation in mice triggers an accelerated, species‐specific rejection
Authors: Triponez F. , Oberholzer J. , Morel P. , Toso C. , Yu D. , Cretin N. , Buhler L. , Majno P. , Mentha G. , Lou J. 
Published: March 2003

SummaryXenogeneic islets could provide an unlimited source of tissue for the treatment of diabetes, and could in theory be transplanted repeatedly in a recipient. However, little is known on the consequences of islet re‐transplantation in a recipient who has rejected a first graft. In this study, we investigated the functional consequence of xeno islet re‐transplantation in mice sensitized with islets from different species. Sprague–Dawley (SD)‐rat islets transplanted in sensitized C57/Bl6 mice that rejected either SD‐ or Lewis‐rat islets underwent accelerated rejection. However, accelerated rejection was not found in mice sensitized with pig or human islets, suggesting that accelerated rejection was species specific. Immunohistochemistry showed increased binding of antibodies and accelerated leucocyte infiltration on re‐grafted islets in sensitized mice. In situ apoptosis detection indicated that islet cell apoptosis was correlated with the time of leucocyte infiltration, but not with the time of antibody binding. In vitro experiments with cultured islet cells showed that although antibody binding was increased after incubation with sensitized mouse serum, islet cell cytotoxicity was not increased, suggesting that humoral immunity did not play a direct role in islet destruction. These results indicate that there is a cell‐mediated, species‐specific accelerated rejection after re‐transplantation of xenogeneic islets.
In vivo rapid reduction of alloantigen‐activated CD8+ mature cytotoxic T cells by inhibitors of acidification of intracellular organelles, prodigiosin 25‐C and concanamycin B
Authors: Lee M.‐H. , Kataoka T. , Honjo N. , Magae J. , Nagai K. 
Published: March 2003

SummaryProdigiosin (PrG) 25‐C and concanamycin B (CMB) are immunosuppressants that specifically inhibit the induction of cytotoxic T cells (CTL) without affecting the function of B cells and helper T cells in vivo. Both compounds inhibit acidification of intracellular organelles and induce destruction of cytotoxic granules and degradation of perforin in vitro. Here we show that a single intraperitoneal (i.p.) injection of PrG 25‐C, and of CMB, into mice eliminates cytotoxic activity 7 days after alloantigen stimulation (when mature CTL activity has been detected in control mice), with minimal effect on the alloantigen‐specific antibody titre in serum. FK506 did not suppress the cytotoxic activity with this administration schedule. Suppression was accompanied by a decrease in the CD8+ population and in perforin expression of spleen cells induced by alloantigen stimulation. The suppression of CTL activity and decrease in CD8+ cell number was detected as early as 7 hr after the injection of compounds. These results suggest that inhibitors of acidification of intracellular organelles suppress CTL activity in vivo by reducing the number of mature CD8+ CTL.
Rewiring of CD40 is necessary for delivery of rescue signals to B cells in germinal centres and subsequent entry into the memory pool
Authors: Siepmann K. , Skok J. , Van Essen D. , Harnett M. , Gray D. 
Published: March 2003

SummaryMemory B‐cell development is impaired by in vivo blockade of the CD40–CD40 ligand (CD40L) interaction using human Fc immunoglobulin G1 (IgG1)‐mouse CD40 fusion protein (CD40‐Ig); however, germinal centre (GC) formation is not. We show here that the block in B‐cell differentiation in these mice is at the stage of rescue from apoptosis and exit from the GC. Thus, GC from CD40‐Ig‐treated mice contain a three‐ to fourfold higher level of apoptotic cells than found in control mice injected with human IgG1 alone. This increase in apoptosis is not caused by a blockade of the CD40L‐mediated rescue signal but is the result of an intrinsic defect of GC B cells in CD40‐Ig‐treated mice to receive rescue signals via CD40. While anti‐CD40 stimulation maintained the viability in culture of GC B cells from control mice, it did not rescue GC B cells from CD40‐Ig‐treated mice. This data is consistent with the notion that a ‘rewiring’ of the CD40 molecule is induced by CD40 ligation early in the response and is necessary to allow B‐cell rescue from apoptosis when they subsequently enter the GC.
Short‐term immunoglobulin A B‐cell memory resides in intestinal lymphoid tissues but not in bone marrow of gnotobiotic pigs inoculated with Wa human rotavirus
Authors: Yuan Lijuan , Geyer Annelize , Saif Linda J. 
Published: March 2003

SummaryImmunological memory is important for protecting the host from reinfection. To investigate the development and sites of residence of intestinal memory B cells, and their role in protective immunity to reinfection with an enteric virus, we assessed the association between memory B cell and antibody‐secreting cell (ASC) responses and protection using a gnotobiotic pig model for human rotavirus (HRV) infection and diarrhoea. The isotypes, quantities and tissue distribution of rotavirus‐specific memory B cells and ASC were evaluated prechallenge (28 and 83 postinoculation days [PID]) and postchallenge (7 postchallenge days [PCD]), using enzyme‐linked immunospot (ELISPOT) assay, in gnotobiotic pigs inoculated once with virulent or three times with attenuated HRV and challenged at PID 28 with the corresponding virulent HRV. Complete protection against HRV shedding and diarrhoea was associated with significantly higher numbers of immunoglobulin A (IgA) and immunoglobulin G (IgG) memory B cells and ASC in the ileum of virulent HRV‐inoculated pigs at challenge. In contrast, pigs inoculated with attenuated HRV had lower numbers of IgA and IgG memory B cells and ASC in intestinal lymphoid tissues, but higher numbers in the spleen. The bone marrow had the lowest mean numbers of IgA and IgG memory B cells and ASC prechallenge in both groups of HRV‐inoculated pigs. Therefore, bone marrow was not a site for IgA and IgG rotavirus‐specific antibody production or for memory B cells after inoculation with live rotavirus, from 28 PID up to at least 83 PID. The effect of in vitro antigen dose was examined and it was determined to play an important role in the development of ASC from memory B cells for the different tissues examined.
Rat mast cell protease‐I enhances immunoglobulin E production by mouse B cells stimulated with interleukin‐4
Authors: Yoshikawa Tsutomu , Imada Teruaki , Nakakubo Hiroshi , Nakamura Norifumi , Naito Koji 
Published: March 2003

SummaryMast cell chymase plays important roles in inflammation and tissue remodeling. Here we show that mast cell chymase also functions as an enhancer of immunoglobulin production. In the culture of murine spleen cells stimulated with lipopolysaccharide and interleukin‐4, purified rat chymase (rat mast cell protease‐I; RMCP‐I), at physiological concentrations, enhanced immunoglobulin E (IgE) and IgG1 syntheses but not IgG3 synthesis. The enhancement was also evident when spleen cells depleted of T cells and macrophages were employed as responding cells. Enzymatic activity of RMCP‐I was required to enhance IgE and IgG1, because two inhibitors for chymotryptic enzymes, chymostatin and Y‐40613, a novel chymase inhibitor, suppressed the enhanced immunoglobulin production, and phenylmethylsulphonyl fluoride, an irreversible inhibitor for serine proteases, totally abolished the enhancing effect. Furthermore, a specific inhibitor for Zn2+‐dependent metalloproteases, GI 129471, could also completely inhibit the production of IgE and IgG1 that was enhanced by RMCP‐I, suggesting that a metalloprotease also played an essential role in the immunoglobulin production. Our results together with others show that proteases from mast cell granules have important function not only in the efferent phase but also in the afferent phase of immune responses.
Adrenaline suppression of the macrophage nitric oxide response to lipopolysaccharide is associated with differential regulation of tumour necrosis factor‐α and interleukin‐10
Authors: Zinyama Rutendo B. , Bancroft Gregory J. , Sigola Lynette B. 
Published: March 2003

SummaryAdrenaline is a catecholamine hormone secreted by the adrenal medulla in response to acute stress. Previous studies have shown that adrenaline suppresses the nitric oxide (NO) response of murine macrophages (Mφs) stimulated in vitro with lipopolysaccharide (LPS). We have now extended these studies to examine the effects of adrenaline on the production of tumour necrosis factor alpha (TNF‐α) and interleukin‐10 (IL‐10). Our results showed that NO, TNF‐α and IL‐10 were concurrently produced following in vitro LPS (10 µg/ml) stimulation of murine peritoneal Mφs. Adrenaline suppressed both NO and TNF‐α with concomitant up‐regulation of the IL‐10 response above that seen with LPS alone. In this in vitro model of LPS stimulation we demonstrated that TNF‐α was required for NO production, as the TNF‐α neutralizing monoclonal antibody, TN3.19.12, abolished the response; in contrast, IL‐10 suppressed NO. In order to determine any functional consequence of adrenaline‐mediated IL‐10 augmentation on NO production, Mφs were stimulated with LPS and specific neutralizing anti‐IL‐10 antibodies were added to the cultures. The LPS NO response was suppressed to 43% of the control value by adrenaline (10−8 m) and an irrelevant control antibody had no effect on the adrenaline‐mediated inhibition of NO, but anti‐IL‐10 treatment restored the NO response to levels similar to those observed with LPS alone. Furthermore, we demonstrated that exogenous TNF‐α, at a dose range of 1·9–50 ng per ml, also restored the nitrite response to LPS in the presence of adrenaline. Together, the observations that neutralization of IL‐10 and addition of TNF‐α abrogate adrenaline's inhibition of NO, suggest that this hormone suppresses NO partly through up‐regulation of IL‐10 which, in turn, may suppress TNF‐α that is required for NO production. Finally, we also observed that the Mφ‐activating cytokine, interferon‐γ (IFN‐γ), attenuated the inhibitory effect of adrenaline on the LPS NO response.
Studies on the association between immunoglobulin E autoreactivity and immunoglobulin E‐dependent histamine‐releasing factors
Authors: Budde Ilona Kleine , De Heer Pleuni G. , Natter Susanne , Mahler Vera , Van Der Zee Jaring S. , Valenta Rudolf , Aalberse Rob C. 
Published: March 2003

SummaryIt has been reported that serum immunoglobulin E (IgE) from certain atopic patients can sensitize basophils to release histamine in response to IgE‐dependent histamine‐releasing factors (HRFs). It has also been shown that patients suffering from severe forms of atopy may contain IgE autoantibodies. It was investigated whether HRF‐responsive sera contained IgE autoantibodies and if there was an association between IgE autoreactivity and IgE‐dependent responsiveness to HRF. The presence of HRF‐responsive IgE (IgE+) in serum of patients with respiratory atopy was determined by stimulating stripped human basophils sensitized by serum with peripheral blood mononuclear cell (PBMC)‐derived HRF, and measuring the release of histamine. In parallel, these sera were screened for the presence of IgE autoantibodies to nitrocellulose‐blotted human cellular extracts. The capacity of IgE autoantigen‐containing preparations to induce histamine release was tested in the stripped basophil assay. Eleven out of 52 sera contained IgE autoantibodies to blotted cellular extracts of human PBMCs or of the human epithelial cell line A431. No significant association was found between IgE autoreactivity and IgE‐dependent responsiveness to HRF: 7/26 IgE+ sera contained IgE to human cellular extracts, and 4/26 of the sera without IgE+ did also. IgE autoantigen‐containing extracts did not induce histamine release of appropriately sensitized basophils. By size‐exclusion chromatography it was shown that a 32 000 MW autoantigen eluted in the >55 000 MW fraction, which indicates that this protein forms polymers or complexes with other macromolecules. This might explain the discrepancy between binding and histamine‐releasing activity. A 20 000 MW IgE‐defined autoantigen cross‐reacted with a shrimp allergen. Our results indicate that IgE‐reactivity to immunoblotted human protein and IgE‐dependent HRF activity are distinct entities that may co‐occur in atopic patients.
Mechanism of antigen presentation after hypertonic loading of soluble antigens
Authors: Enders Georg A. 
Published: March 2003

SummaryHypertonic loading of proteins into cells has been used to introduce soluble proteins into the major histocompatibility complex class I pathway of antigen presentation followed by cytotoxic T‐lymphocyte (CTL) induction. The precise mechanism for this pathway is not completely understood. The antigen is either processed and presented by/on the same cell or by professional antigen‐presenting cells (APC) after taking up the antigen from damaged or apoptotic cells. After loading labelled ovalbumin (OVA), it could be co‐precipitated with the proteasome complex, supporting the role of this pathway for antigen processing. The processing speed however, appeared to be slow since intact OVA could be detected inside the cells even after 18 hr. This corresponded well with the processing of OVA by isolated proteasomes. On the other hand, enough peptides for recognition of target cells by CTLs were generated in this reaction. One reason for the low level of processing might be that hypertonic loading may damage the cells and inhibit direct processing. In fact, at least 50% of the cells became positive for Annexin V binding after hypertonic loading which indicates severe membrane alterations usually associated with the progress of apoptosis. Annexin V binds to phosphatidylserine residues which also serve as ligand for CD36 expressed on monocytes and some immature dendritic cells. This may direct the phagocytic pathway to hypertonically loaded cells and thus enable professional APCs to present OVA‐peptides. Therefore, in addition to the direct processing of OVA, CTLs can be primed by professional APC after uptake of apoptotic, OVA‐loaded cells.
Induction of immunoglobulin G1, interleukin‐6 and interleukin‐10 by Taenia crassiceps metacestode carbohydrates
Authors: Dissanayake Senarath , Khan Nasir , Shahin Allen , Wijesinghe Shanaka , Lukic Miodrag 
Published: March 2003

SummaryT helper type 2 (Th2) ‐polarized immune responses are characteristically dominant in helminth infections. Two murine models that show a Th1 to Th2 polarization with infection progression are those of Schistosoma mansoni and Taenia crassiceps. In both, an early Th1 response is replaced by a late Th2 response. We report that the nucleic acid‐, protein‐ and lipid‐free carbohydrate fraction of T. crassiceps metacestodes (denoted T‐CHO) possesses Th2‐like immunomodulatory activity. Immunization of two strains of rats (Dark Agouti and Albino Oxford) and BALB/c mice with chicken albumin in the presence of T‐CHO resulted in selective enhancement of immunoglobulin G1 (IgG1) antibodies, considered to be associated with Th2 responses in both rats and mice. Interleukin‐6 (IL‐6) followed by IL‐10 were the dominant cytokines detected in in vitro cultures of mouse spleen cells stimulated with T‐CHO. IL‐4 and IL‐5 were not detected in these culture supernates. Furthermore, Taenia carbohydrates were mitogenic to spleen cells, activated serine phosphorylation of proteins and up‐regulated the expression of the anti‐apoptotic protein, Bcl‐2. When mouse spleen cells were cultured in the presence of Taenia carbohydrates, a concentration‐dependent down‐regulation of IL‐2 and an overlapping up‐regulation of IL‐6 secretion were seen.
Distribution of Toll‐like receptor 1 and Toll‐like receptor 2 in human lymphoid tissue
Authors: Ochoa Maria‐Teresa , Legaspi Annaliza J. , Hatziris Zena , Godowski Paul J. , Modlin Robert L. , Sieling Peter A. 
Published: March 2003

SummaryTo determine how distinct receptors of the immune system can contribute to innate immunity, we investigated the pattern of Toll‐like receptor 1 (TLR1) and TLR2 expression in human lymphoid tissue. We found that TLR1 and TLR2 were co‐expressed on cells of the innate immune system, including macrophages and dendritic cells. In addition, TLR1 and TLR2 were expressed in mucosa‐associated lymphoid tissue on tonsillar crypt epithelium. Of the lymphoid tissue examined, spleen expressed the highest levels of TLR2. Although TLR1‐ and TLR2‐positive cells were in close proximity to T lymphocytes in vivo, lymphocytes themselves were devoid of TLR1 and TLR2 expression. The co‐expression of TLR1 and TLR2 on myeloid cells in lymphoid tissue provides the host with the ability to respond to a variety of microbial ligands at sites conducive to the generation of an immune response.
Breast milk macrophages spontaneously produce granulocyte–macrophage colony‐stimulating factor and differentiate into dendritic cells in the presence of exogenous interleukin‐4 alone
Authors: Ichikawa Masao , Sugita Masahiko , Takahashi Megumi , Satomi Misao , Takeshita Toshiyuki , Araki Tsutomu , Takahashi Hidemi 
Published: March 2003

SummaryPeripheral blood monocytes extravasate and differentiate into tissue macrophages to mediate effective local defence, but how tissue‐specific stimuli and environments may influence their functions remains unknown. Here, we found that peripheral blood monocytes gained the ability to produce granulocyte–macrophage colony‐stimulating factor (GM‐CSF) upon exposure to breast milk and differentiated into CD1+ dendritic cells (DCs) in the presence of exogenous interleukin‐4 (IL‐4) alone. This in vitro observation appeared physiologically relevant since macrophages that were freshly isolated from breast milk were also found to produce GM‐CSF spontaneously. Furthermore, in contrast to peripheral blood monocytes that differentiated into DCs only in the presence of both exogenous GM‐CSF and IL‐4, differentiation of breast milk macrophages into DCs was induced by incubation with exogenous IL‐4 alone. These IL‐4‐stimulated breast milk macrophages were efficient in stimulating T cells, suggesting their potential role in mediating T‐cell‐dependent immune responses in situ. On the other hand, unexpected expression of DC‐SIGN, a DC‐specific receptor for human immunodeficiency virus (HIV), even in unstimulated breast milk macrophages, may favour HIV infection, resulting in an increased risk of mother‐to‐infant vertical transmission of the virus via breast milk. Thus, tissue‐specific development of macrophages is often linked to effective local immunity, but may potentially provide an opportunity for a pathogen to spread and transmit.
Relative abundance, isolation and structure of phlebotomine microsatellites
Authors: Day J. C. , Ready P. D. 
Published: March 2003

AbstractPopular classes of microsatellites are not always abundant in insects or easily isolated from them. Dot‐blot hybridizations demonstrated much variation in the relative abundance of four repeat classes in four phlebotomine sandfly species. Only AAT‐class repeats were specifically isolated from a phagemid library of Lutzomyia whitmani, even though other microsatellites had similar abundances. An enrichment step would have targeted classes but was omitted because relatively long flanking sequences were sought. All fourteen sandfly loci had a non‐coding structure, and a minority of dipteran AAT‐class repeats found in DNA databases and the literature were from exons. Therefore, this class should often provide neutral alleles for population studies. Perfect, not imperfect, AAT‐class repeats were polymorphic in wild L. whitmani.
Diversity of odourant binding proteins revealed by an expressed sequence tag project on male Manduca sexta moth antennae
Authors: Robertson H. M. , Martos R. , Sears C. R. , Todres E. Z. , Walden K. K. O. , Nardi J. B. 
Published: March 2003

AbstractA small expressed sequence tag (EST) project generating 506 ESTs from 375 cDNAs was undertaken on the antennae of male Manduca sexta moths in an effort to discover olfactory receptor proteins. We encountered several clones that encode apparent transmembrane proteins; however, none is a clear candidate for an olfactory receptor. Instead we found a greater diversity of odourant binding proteins (OBPs) than previously known in moth antennae, raising the number known for M. sexta from three to seven. Together with evidence of seventeen members of the family from the Drosophila melanogaster genome project, our results suggest that insects may have many tens of OBPs expressed in subsets of the chemosensory sensilla on their antennae. These results support a model for insect olfaction in which OBPs selectively transport and present odourants to transmembrane olfactory receptors. We also found five members of a family of shorter proteins, named sensory appendage proteins (SAPs), that might also be involved in odourant transport. This small EST project also revealed several candidate odourant degrading enzymes including three P450 cytochromes, a glutathione S‐transferase and a uridine diphosphate (UDP) glucosyltransferase. Several first insect homologues of proteins known from vertebrates, the nematode Caenorhabditis elegans, yeast and bacteria were encountered, and most have now also been detected by the large D. melanogaster EST project. Only thirteen entirely novel proteins were encountered, some of which are likely to be cuticle proteins.