bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC)
Authors: Arosa F A , Irwin C , Mayer L , DE Sousa M , Posnett D N 
Published: March 2003

SUMMARYIntestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28− phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8+ CD28− T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8+ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8+ CD28+ and CD8+ CD28− T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8+ CD28− cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8+ CD28− phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vβ subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8+ CD28− T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8+ CD28− T cells in the iIEL compartment.
Augmented levels of macrophage and Th1 cell-related cytokine mRNA in submandibular glands of MRL/lpr mice with autoimmune sialoadenitis
Authors: Mustafa W , Zhu J , Deng G , Diab A , Link H , Frithiof L , Klinge B 
Published: March 2003

SUMMARYMRL/Mp-lpr/lpr (MRL/lpr) mice spontaneously develop destructive inflammation of the salivary and lachrymal glands resembling Sjögren's syndrome (SS), representing an animal model to study this disease. We used in situ hybridization with synthetic radiolabelled oligonucleotide probes to examine expression of mRNA encoding pro- and anti-inflammatory cytokines in submandibular glands of 2, 3, 4 and 5-month-old MRL/lpr mice. Phenotypic composition of submandibular gland infiltrates was evaluated by immunohistochemistry. Cells expressing tumour necrosis factor-alpha (TNF-α), IL-1β, IL-6 and IL-12 mRNA were strongly up-regulated at about the time of onset of sialoadenitis, suggesting a role of these cytokines in development of the disease. Interferon-gamma (IFN-γ) and cytolysin mRNA-expressing cells were gradually up-regulated over the disease course up to 5 months of age, the time when sialoadenitis is at its height, favouring a role of these cytokines in progression of the disease as well. Low levels of IL-10 and transforming growth factor-beta (TGF-β) mRNA-expressing cells were observed at 2, 3 and 4 months of age, and were almost undetectable at 5 months. Maximum levels of CD4+, CD8+ and interdigitating/dendritic cells, as well as of MHC class II and MHC class I expression were seen at 3 months, with CD4+ outnumbering CD8+ cells. Maximum levels of macrophages were seen at 4 months of age. These data argue for a major role of the proinflammatory cytokines TNF-α, IL-1β, IL-6, IL-12, IFN-γ and cytolysin in initiation and perpetuation of autoimmune sialoadenitis in MRL/lpr mice, probably in conjunction with an insufficiency of the anti-inflammatory cytokines TGF-β and IL-10.
Hyposensitization to allergic reaction in rDer f 2-sensitized mice by the intranasal administration of a mutant of rDer f 2, C8/119S
Authors: Yasue M , Yokota T , Fukada M , Takai T , Suko M , Okudaira H , Okumura Y 
Published: March 2003

AbstractC8/119S is a mutant of recombinant Der f 2 (rDer f 2), and lacks a disulphide bond possessed by wild-type rDer f 2. In humans and mice, C8/119S has a very weak IgE-binding capacity compared with the wild-type, but possesses a T cell reactivity comparable to that of the wild-type. C8/119S may thus be a safe immunotherapeutic agent for house dust mite allergy. The aim of the present study was to evaluate whether the intranasal administration of C8/119S could suppress an immediate allergic reaction in mice sensitized with wild-type rDer f 2, possessing an allergic activity comparable to native counterparts purified from mite extract. Seven-week-old male A/J mice were immunized with wild-type rDer f 2 four times, and then intranasally administered 0.2–2 μg of wild-type, 0.2–20 μg of C8/119S, or PBS alone, three times a week for 4 weeks. Seven days after the last administration, the mice were examined for an immediate allergic reaction. The animals administered 2 μg of C8/119S (C2.0 group) showed significantly reduced immediate bronchoconstriction provoked by the i.v. injection of 1 and 10 μg of wild-type rDer f 2, compared with the PBS-treated mice. Similar results were obtained when we examined mice 10 weeks after the last administration. The reactions in the other groups given wild-type or C8/119S also tended to decrease in severity in comparison with the animals of the PBS group. The allergic phenotypes of the T cells, B cells, and basophils in the C2.0 group were shifted to that of naive mice without immunization. We conclude that C8/119S has hyposensitizing activities in mice sensitized with wild-type rDer f 2. C8/119S may be useful for immunotherapy of house dust mite allergy.
Surface activation markers of T lymphocytes: role in the detection of infection in neonates
Authors: Hodge S , Hodge G , Flower R , Han P 
Published: March 2003

AbstractDiagnosis of perinatal infection in the newborn is difficult; there may be few clinical signs and current tests are slow or non-specific. Detection of organisms, antigen or specific antibody to common pathogens often requires repeat samples and does not give immediate results. Haematological parameters, although relied upon frequently to diagnose infection in the neonate prior to a positive bacterial isolation, are unreliable and insensitive. Indicators such as an increase in neutrophil band cell counts are highly variable between morphologists. Infection induces the expression of a number of T lymphocyte surface markers, including CD45RA/CD45RO and CD45RO. The use of changed expression of surface markers as a laboratory test for detection of infection in neonates was evaluated. We used multiparameter flow cytometry to detect expression of early (CD45RA/CD45RO) and late (CD45RO) activation markers. In the respective groups of 50 full term (including 25 normal vaginal deliveries and 25 caesarean deliveries) and 30 premature, i.e. &lt; 36 weeks gestation (born by either normal vaginal delivery or caesarean delivery) the CD45RA isoform was brightly expressed on newborn ‘naive’ CD4+ T cells, whereas the CD45RO isoform (including both ‘bright’ and ‘dim’ populations) was present on &lt; 19% of CD4+ T cells from these newborn infants. In a group of 37 infants, tested to evaluate possible effects of non-infective parameters such as respiratory distress and iso-immunization, no significant changes in surface marker expression were found and specificity of the test was confirmed. In 14 neonates with documented sepsis, up-regulation of dual staining CD45RA/CD45RO isoforms on CD4+ T cells was detected early in the infection. In addition, we found that CD45RO expression persisted for several weeks after bacterial infection, and up to several months in viral infection. In conclusion, detection of T cell activation by flow cytometry for the early diagnosis of neonatal infection is an easy test to carry out on small volumes of blood, is inexpensive, and may be a specific indicator of infection.
Effect of a platelet-activating factor (PAF) receptor antagonist on hyperacute xenograft rejection; evaluation in a pig kidney–human blood xenoperfusion model
Authors: Cruzado J M , Torras J , Riera M , Lloberas N , Herrero I , Condom E , Martorell J , Alsina J , Grinyó J M 
Published: March 2003

AbstractIn pig to human discordant xenotransplantation, PAF may contribute to the pathogenesis of hyperacute xenograft rejection (HXR). We examined the release of PAF and the effect of a PAF receptor antagonist (BN 52021) on HXR in a pig kidney–human blood xenoperfusion model. Pig kidneys were perfused with porcine blood (AUTO group, n = 5), human blood (HETER group, n = 6) or human blood plus BN 52021 (BN group, n = 4), respectively. In contrast to HETER kidneys that never produced urine and were rejected in 15–30 min, the administration of BN 52021 induced a partial recovery of glomerular filtration rate and allowed kidneys to function until the end of the study. The release of PAF and soluble P-selectin, as well as endothelial P-selectin expression and tissue myeloperoxidase (MPO), were much higher in the HETER than in the AUTO group. HETER and BN kidneys displayed similar natural xenoantibody titres, CH50, PAF, soluble P-selectin as well as renal immunoglobulin (IgM, IgG, IgA) and complement (C3, C1q) deposition. However, HETER kidneys displayed a full histologic picture of HXR (mainly interstitial haemorrhage and vascular microthrombi) and BN kidneys had only endothelial cell swelling. Also, BN 52021 administration attenuated glomerular and vascular P-selectin expression and renal tissue MPO activity. We conclude that in the pig kidney–human blood xenoperfusion model, PAF is produced in higher amounts than in the pig kidney–pig blood autologous combination. The administration of BN 52021 exerts a protective effect by means of attenuating the acute inflammatory response and blocking vascular microthrombi formation.
Surface expression and release of soluble forms of CD8 and CD23 in CD40- and IL-4-activated mononuclear cells from patients with Graves' disease (GD)
Authors: Itoh M , Uchimura K , Hayakawa N , Makino M , Hayashi R , Nagata M , Kakizawa H , Nagasaka A , Sakamoto H , Kuzuya H 
Published: March 2003

SUMMARYWe investigated the effect of T cell-dependent B cell activation on the surface expression and release of the soluble forms of CD8 and CD23 by peripheral blood mononuclear cells (PBMC) obtained from patients with GD, versus patients with Hashimoto's thyroiditis, and normal controls. Incubating the PBMC with anti-CD40 MoAbs and IL-4 increased the soluble CD23 levels in cells from all three groups. An increase in the number of CD23+ cells was observed in the PBMC from the patients with GD, but not in PBMC from Hashimoto's thyroiditis or controls. Less soluble CD8 was released from anti-CD40 antibody and IL-4-stimulated PBMC obtained from patients with GD relative to those from the controls. In addition, the number of CD8+ cells was significantly reduced in stimulated PBMC from the GD patients relative to those from controls. Incubation of PBMC with anti-CD40 antibody plus IL-4 did not affect the proportions of CD4+, CD20+, Fas+CD4+, and Fas+CD8+ cells. The addition of T3 to cultured PBMC from controls did not reproduce the changes in CD23+ and CD8+ cells noted in the samples from GD patients. Thus, T cell-dependent B cell activation, mediated by a CD40 pathway, may reduce the number of CD8+ cells, causing exacerbation of GD.
Somatic mutation of immunoglobulin VH6 genes in human infants
Authors: Ridings J , Dinan L , Williams R , Roberton D , Zola H 
Published: March 2003

SUMMARYInfants respond to antigen by making antibody that is generally of low affinity for antigen. Somatic hypermutation of immunoglobulin genes, and selection of cells expressing mutations with improved affinity for antigen, are the molecular and cellular processes underlying the maturation of antibody affinity. We have reported previously that neonates and infants up to 2 months of age, including individuals undergoing strong immunological challenge, show very few mutated VH6 sequences, with low mutation frequencies in mutated sequences, and little evidence of selection. We have now examined immunoglobulin genes from healthy infants between 2 and 10 months old for mutation and evidence of selection. In this age group, the proportion of VH6 sequences which are mutated and the mutation frequency in mutated sequences increase with age. There is evidence of selection from 6 months old. These results indicate that the process of affinity maturation, which depends on cognate T–B cell interaction and functional germinal centres, is approaching maturity from 6 months old.
Leprosy patients with lepromatous disease recognize cross-reactive T cell epitopes in theMycobacterium leprae10-kD antigen
Authors: Hussain R , Dockrell H M , Shahid F , Zafar S , Chiang T J 
Published: March 2003

SUMMARYT cell responses play a critical role in determining protective responses to leprosy. Patients with self-limiting tuberculoid leprosy show high T cell reactivity, while patients with disseminated lepromatous form of the disease show absent to low levels of T cell reactivity. Since the T cell reactivity of lepromatous patients to purified protein derivative (PPD), a highly cross-reactive antigen, is similar to that of tuberculoid patients, we queried if lepromatous patients could recognize cross-reactive epitopes in Mycobacterium leprae antigens as well. T cell responses were analysed to a recombinant antigen 10-kD (a heat shock cognate protein) which is available from both M. tuberculosis (MT) and M. leprae (ML) and displays 90% identity in its amino acid sequence. Lymphoproliferative responses were assessed to ML and MT 10 kD in newly diagnosed leprosy patients (lepromatous, n = 23; tuberculoid, n = 65). Lepromatous patients showed similar, but low, lymphoproliferative responses to ML and MT 10 kD, while tuberculoid patients showed much higher responses to ML 10 kD. This suggests that the tuberculoid patients may be recognizing both species-specific and cross-reactive epitopes in ML 10 kD, while lepromatous patients may be recognizing only cross-reactive epitopes. This was further supported by linear regression analysis. Lepromatous patients showed a high concordance in T cell responses between ML and MT 10 kD (r = 0.658; P &lt; 0.0006) not observed in tuberculoid patients (r = 0.203; P &gt; 0.1). Identification of cross-reactive T cell epitopes in M. leprae which could induce protective responses should prove valuable in designing second generation peptide-based vaccines.
Processing of the DRB1*1103-restricted measles virus nucleoprotein determinant 185–199 in the endosomal compartment
Authors: Demotz S , Ammerlaan W , Fournier P , Muller C P , Barbey C 
Published: March 2003

SUMMARYMHC class II molecules present to CD4+ T cells protein fragments which mostly derive from the extracellular and from the endosomal compartments. Determinants of cytosolic proteins are, however, also displayed by MHC class II molecules following pathways which are still not yet fully characterized. Here we describe the isolation of DRB1*1103-restricted T cell clones specific for the measles virus (MV) nucleoprotein peptide 185–199 (N185). Experiments were then conducted to delineate how this determinant is assembled with DR molecules. In vitro binding analyses indicated that complexes between the N185 peptide and DRB1*1103 protein are optimally constituted at pH 4–4.5. In cellular experiments it was observed that chloroquine, leupeptin and emetine, which are classical inhibitors of presentation of MHC class II-restricted antigens, when added during infection of B cells with MV, prevent presentation of the N185 determinant. In addition, it was found that the N185 determinant is efficiently presented when the nucleoprotein is exogenously provided to B cells, either by blocking MV fusion with the peptide FFG or by the use of purified nucleoprotein. In contrast, it was observed that nucleoprotein recombinant vaccinia virus (vv-N)-infected B cells weakly stimulated N185-specific T cells, indicating that the restricted localization of the nucleoprotein in the cytosol resulted in a poor presentation of the N185 determinant. Taken together, these findings suggest that it is prior to delivery of the nucleoprotein into the cytosol that the N185 determinant is efficiently assembled with newly synthesized DR molecules in the acidic environment of the endosomal compartment.
Protection of human breast cancer cells from complement-mediated lysis by expression of heterologous CD59
Authors: YU J , CARAGINE T , CHEN S , MORGAN B P , FREY A B , TOMLINSON S 
Published: March 2003

SUMMARYCD59, decay accelerating factor (DAF) and membrane cofactor protein (MCP) are widely expressed cell surface glycoproteins that protect host cells from the effects of homologous complement attack. Complement inhibitory activity of these proteins is species-selective. We show that the human breast cancer cell line MCF7 is relatively resistant to lysis by human complement, but is effectively lysed by rat or mouse complement. CD59, DAF and MCP were all shown to be expressed by MCF7. The species-selective nature of CD59 activity was used to demonstrate directly the effectiveness of CD59 at protecting cancer cells from complement-mediated lysis. cDNAs encoding rat and mouse CD59 were separately transfected into MCF7 cells, and cell populations expressing high levels of the rodent CD59 were isolated by cell sorting. Data show that rat and mouse CD59 were highly effective at protecting transfected MCF7 cells from lysis by rat and mouse complement, respectively. Data further reveal that rat CD59 is not effective against mouse complement, whereas mouse CD59 is effective against both mouse and rat complement. These studies establish a model system for relevant in vivo studies aimed at determining the effect of complement regulation on tumourigenesis, and show that for effective immunotherapy using complement-activating anti-tumour antibodies, the neutralization of CD59 and/or other complement inhibitory molecules will probably be required.
Effect of protease therapy on cytokine secretion by peripheral blood mononuclear cells (PBMC) from HIV-infected subjects
Authors: KELLEHER A D , SEWELL W A , COOPER D A 
Published: March 2003

SUMMARYThe viral load reduction seen in patients with late stage HIV infection treated with the protease inhibitor, ritonavir, is accompanied by increases in the in vitro proliferative responses generated by PBMC. The present study was undertaken to investigate which lymphocyte subsets generated these responses and the effects of therapy on cytokine production. Lymphoproliferation following phytohaemagglutinin (PHA) stimulation was studied by thymidine incorporation, and production of IL-2, interferon-gamma (IFN-γ) and IL-4 was assessed by ELISA in 12 patients receiving ritonavir and seven receiving placebo in the context of randomized, blinded clinical trials. CD4+ cell-depleted and CD8+ cell-depleted subsets were obtained from PBMC by immunomagnetic bead depletion. At week 4 of therapy a two-fold or greater increase in proliferative responses was observed in 9/12 subjects receiving therapy, compared with 0/7 receiving placebo. Similarly there was a significant increase in IL-2 and IFN-γ production of 2.7-fold (P = 0.02) and 1.7-fold (P = 0.03), respectively, in the treatment group compared with those receiving placebo. No change in IL-4 production was observed. Despite these increases, cytokine responses post-therapy were still reduced compared with both healthy controls and asymptomatic HIV-infected subjects. Increases in proliferative response and IL-2 production were greater in the CD8+ cell-depleted population than in the CD4+ cell-depleted population, whereas increases in IFN-γ production were derived from the CD4+ cell-depleted population.
Swine dust induces cytokine secretion from human epithelial cells and alveolar macrophages
Authors: WANG Z , MALMBERG P , EK A , LARSSON K , PALMBERG L 
Published: March 2003

SUMMARYExposure to swine dust causes airway inflammation with increased levels of proinflammatory cytokines, and inflammatory cells in nasal and bronchoalveolar lavage fluid (BALF) in healthy subjects. Earlier studies have suggested that lipopolysaccharides (LPS) might be an important proinflammatory factor in swine dust. Since respiratory epithelial cells and alveolar macrophages are target cells for the inhaled dust, we therefore compared the release of proinflammatory cytokines from normal human bronchial epithelial cells (NHBE), an epithelial cell line (A549) and from human alveolar macrophages obtained from BALF from healthy subjects in vitro after incubation with dust collected in swine houses or LPS. Swine dust or LPS was added to the wells with A549 cells or macrophages and incubated for 8 h at concentrations of 12.5, 25, 50 and 100 μg/ml. NHBE cells were incubated with swine dust at a concentration of 25, 50 or 100 μg/ml or with LPS at a concentration of 50 or 100 μg/ml and incubated for 24 h. The supernatants were collected, centrifuged, and IL-6, IL-1β and tumour necrosis factor-alpha (TNF-α) production was measured using an ELISA method and expressed per 106 cells. Swine dust and LPS caused a dose-dependant increase of IL-6 production in NHBE cells, swine dust being more potent than LPS. In A549 cells, only swine dust, but not LPS caused an increase of IL-6 production. Neither swine dust nor LPS induced IL-1β or TNF-α release from A549 cells. Both swine dust and LPS caused a dose-dependent increase of IL-1β, IL-6 and TNF-α in alveolar macrophages. Swine dust which contained 2.2 (0.2) ng endotoxin/100 μg swine dust (0.02‰) was almost as potent as LPS in inducing cytokine release from alveolar macrophages in vitro. We conclude that both epithelial cells and alveolar macrophages have the capability to contribute to the release of proinflammatory cytokines following exposure to swine dust. Some agent(s) other than LPS in the dust contribute to the marked airway inflammatory reaction.
Interactions of allogeneic human mononuclear cells in the two-way mixed leucocyte culture (MLC): influence of cell numbers, subpopulations and cyclosporin
Authors: SATO T , DEIWICK A , RADDATZ G , KOYAMA K , SCHLITT H J 
Published: March 2003

SUMMARYWith organ allografts considerable numbers of donor-type mononuclear cells are transferred to the recipient, leading to bilateral immunological interactions between donor and recipient lymphocytes. To study such bilateral immune reactions in detail, human two-way MLC were performed. In this model proliferation kinetics, patterns of activation, and survival of the two populations were analysed, and the relevance of initial cell subset composition, relative cell numbers, and the effect of immunosuppression on this co-culture were evaluated. It could be demonstrated that with an initial 50:50 ratio of two populations of allogeneic cells one population dominated after 21 days of co-culture in 78 out of 80 combinations (97%) tested; the other population decreased markedly after an initially stable phase of 6–7 days. With unequal starting conditions the larger population dominated when resting cells were used, but small populations of preactivated cells or separated CD8+ cells could also dominate. Depletion of CD16+ natural killer (NK) cells and of CD2− cells (B cell and monocytes) had no effect on domination. Addition of cyclosporin delayed or blocked the domination process while addition of IL-2 accelerated it. Disappearance of one population was associated with detection of apoptotic cells. The findings indicate that co-cultures of allogeneic mononuclear cells are generally not stable for more than 1 week, but lead to active elimination of one population. CD8+ cells and particularly preactivated cells seem to play the most important role in that process, while NK cells are of less importance. Cyclosporin can prolong survival of allogeneic cells in co-culture. These observations suggest that under the conditions of clinical organ transplantation even small amounts of immunocompetent donor cells transferred by the graft may persist for some time and may, thereby, have the chance to exert immunomodulatory functions.