bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disparate effects of phorbol esters, CD3 and the costimulatory receptors CD2 and CD28 on RANTES secretion by human T lymphocytes
Authors: Sotsios Y. , Blair P. J. , Westwick J. , Ward S. G. 
Published: March 2003

SummaryThis study has examined the stimuli required for secretion of regulated upon activation, normal T‐cell expressed, presumed secreted (RANTES) from T lymphocytes and found that stimuli such as phorbol 12‐myristate 13‐acetate (PMA), which are unable to support T‐cell proliferation and interleukin‐2 (IL‐2) production, are nevertheless able to elicit strong secretion of RANTES. Conversely, stimuli such as CD2 and CD28 ligation, which are able to support T‐cell proliferation, are unable to elicit RANTES secretion. Coligation of CD3 and CD28 drives T‐cell proliferation to a similar degree as CD2 and CD28 coligation, yet also supports modest RANTES secretion. Furthermore, CD28 ligation enhances the secretion of RANTES stumulated by PMA and this costimulatory effect is abrogated by the phosphoinositide 3‐kinase inhibitor wortmannin. Our data also indicate that the observed effects of PMA on RANTES secretion are probably due to activation of protein kinase C (PKC) isoenzymes, since RANTES secretion was unaffected by the non‐PKC activating 4α‐phorbol ester, whilst the general PKC inhibitor Ro‐32‐0432 inhibits PMA‐stimulated RANTES secretion. Moreover, the effect of PMA appears to be chemokine‐specific because PMA was unable to increase secretion of the related CC chemokine MIP‐1α. Under stimulation conditions where increases in [Ca2+]i occur (e.g. PMA plus ionomycin or CD3 plus CD28 ligation) RANTES secretion can be severely reduced compared with the levels observed in response to the phorbol ester PMA. Hence, whilst PKC‐dependent pathways are sufficient for strong RANTES secretion, a calcium‐dependent factor is activated which negatively regulates RANTES secretion. This correlates well with the observation that ligation of cytolytic T lymphocyte‐associated antigen‐4 (CTLA‐4) (expression of which has been reported to be dependent on a sustained calcium signal), inhibits RANTES secretion induced by CD3/CD28, but has no effect on PMA‐stimulated RANTES secretion.
Alteration in the responsiveness to tumour necrosis factor‐α is crucial for maximal expression of monocyte chemoattractant protein‐1 in human neutrophils
Authors: Yamashiro S. , Kamohara H. , Yoshimura T. 
Published: March 2003

SummaryWe previously reported delayed expression of monocyte chemoattractant protein‐1 (MCP‐1) in human neutrophils cultured with a cytokine‐rich crude supernatant of phytohaemagglutinin‐stimulated peripheral blood mononuclear cells (PHA‐sup). Tumour necrosis factor‐α (TNF‐α) contained in the PHA‐sup played a key role in this event, but there appeared to be another factor(s) in the same supernatant that co‐operated with TNF‐α for maximal MCP‐1 expression. In the present study, we reduced TNF‐α concentrations in the PHA‐sup to minimal levels using anti‐TNF‐α affinity columns (TNF‐depleted‐sup) and investigated the co‐operation between TNF‐α and TNF‐depleted‐sup. Nine hours of preincubation with TNF‐depleted‐sup altered the responsiveness of neutrophils to TNF‐α and enabled TNF‐α to increase the level of MCP‐1 expression to a maximal level within 4 hr. The priming effect was not due to the increased expression of cell‐surface TNF receptors. However, the activation of primed cells by TNF‐α was clearly through TNF receptor–p55. Finally, the activity in the TNF‐depleted‐sup that co‐operated with TNF‐α was eluted at 60 000 MW on high‐performance liquid chromatography–gel filtration. Thus, delayed neutrophil expression of MCP‐1 is regulated by a cytokine‐dependent mechanism that induces neutrophils to enter a ‘mature’ stage.
Analysis of the mechanism for extracellular processing in the presentation of human immunodeficiency virus‐1 envelope protein‐derived peptide to epitope‐specific cytotoxic T lymphocytes
Authors: Nakagawa Y. , Takeshita T. , Berzofsky J. A. , Takahashi H. 
Published: March 2003

SummaryAn immunodominant epitope of human immunodeficiency virus‐1 (HIV‐1) gp160 recognized by Dd class I major histocompatibility complex (MHC) molecule‐restricted, CD8+ cytotoxic T lymphocytes (CTL) was originally identified as a peptide composed of 15 amino acids (P18IIIB: RIQRGPGRAFVTIGK). However, further study has indicated that a 10‐mer peptide, I‐10 (RGPGRAFVTI), within P18IIIB is the minimal‐sized epitope and the trimming step(s) of two carboxyl terminal amino acids (GK) is essential to produce I‐10 from P18IIIB. In the processing, angiotensin‐1‐converting enzyme (ACE), found in sera, plays a central role in generating I‐10. Target cells could be sensitized with I‐10 under conditions where ACE activity in the sera was abrogated. In contrast, in the case of P18IIIB, requiring further processing to delete the C‐terminus of two amino acids in order to act, sensitization of target cells was completely abrogated under the conditions. Pretreatment of target cells with brefeldin A (BFA), preventing the presentation of endogenous antigens from the class I MHC molecule pathway, did not inhibit the presentation of P18IIIB. Moreover, glutaraldehyde‐fixed cells, which can not process native protein, though they could present the exogenously added peptides, were also sensitized by P18IIIB. These results clearly demonstrate that the fine processing to produce I‐10 occurred in the extracellular milieu. Furthermore, our result suggests that the longer P18IIIB can bind to the class I molecules on the cell surface, and then be trimmed by ACE while it is bound. The mechanisms behind the extracellular processing outlined in this paper will offer important information for designing peptide‐based vaccines to elicit MHC molecule‐restricted effectors.
Human endothelial cells are activated by interferon‐γ plus tumour necrosis factor‐α to kill intracellular Pseudomonas aeruginosa
Authors: De Assis M. C. , Da Costa A. O. , Barja‐Fidalgo T. C. , Plotkowski M. C. 
Published: March 2003

SummaryProinflammatory cytokines have been shown to activate endothelial cells. To investigate the effect of cytokines on the interaction of human umbilical vein endothelial cells (HUVEC) with Pseudomonas aeruginosa, cells were treated with interferon‐γ (IFN‐γ) plus tumour necrosis factor‐α (TNF‐α) for 24 hr and exposed to P. aeruginosa suspension for 1 hr. Light microscopy showed that activated cells internalized significantly more bacteria than control cells. To ascertain the effect of cytokines on the microbicidal activity of HUVEC, the concentrations of viable intracellular (IC) bacteria in control and activated cells were determined, at 1 and 5 hr postinfection, by the gentamicin exclusion assay. In control cells, no significant decrease in the concentration of bacteria was detected 5 hr postinfection. In contrast, in activated cells the concentration of viable bacteria at 5 hr was significantly lower. Concentrations of superoxide and hydrogen peroxide detected in supernatants of activated cells were significantly higher than in control cell supernatants. HUVEC anti‐P. aeruginosa activity was insensitive to the antioxidants superoxide dismutase, dimethylthiourea and allopurinol as well as to the
l‐arginine analogues aminoguanidine and NG‐monomethyl‐
l‐arginine (
l‐NMMA), but was significantly inhibited by catalase. Our results indicate that HUVEC can be activated by IFN‐γ plus TNF‐α to kill IC P. aeruginosa and suggest a role for reactive oxygen radicals, notably hydrogen peroxide, in HUVEC antibacterial activity.
Induction of specific transplantation immunity by oral immunization with allogeneic cells
Authors: Holáň V. , Zajícová A. , Krulová M. , Plšková J. , Frič J. , Filipec M. 
Published: March 2003

SummaryOral administration of antigen has been shown to be effective for both positive and negative modulation of immune responses. In the present study we characterized changes in the reactivity of the immune system after oral immunization with allogeneic spleen cells. Mice were orally immunized for 10 consecutive days with fresh allogeneic spleen cells, and the phenotype, proliferative response, cytotoxic activity and cytokine production profile of recipient spleen cells were assessed 1 or 7 days after the last immunization dose. Although no significant changes in the proportion of CD4+, CD8+ or CD25+ cells were observed in the spleen of orally immunized mice, significant activation of alloreactivity in spleen cells was found. Cells from orally immunized mice exhibited enhanced proliferation and cytotoxic activity after stimulation with specific allogeneic cells in vitro, and produced considerably higher concentrations of interferon‐γ (IFN‐γ) and significantly less interleukin (IL)‐4 than did cells from control mice. The production of IL‐2 was essentially unchanged and that of IL‐10 was only slightly increased. The systemic allosensitization induced by oral immunization was demonstrated in vivo by increased resistance to the growth of allogeneic tumours induced by subcutaneous inoculation of high doses of tumour cells. In addition, orthotopic corneal allografts in orally immunized recipients were rejected more rapidly (in a second‐set manner) than in control, untreated recipients. These data show that oral immunization with allogeneic cells modulates individual components of the immune response and that specific transplantation immunity, rather than tolerance, is induced in the treated recipients.
Antigen‐specific proliferation of porcine CD8αα cells to an extracellular bacterial pathogen
Authors: Waters W. R. , Hontecillas R. , Sacco R. E. , Zuckermann F. A. , Harkins K. R. , Bassaganya‐Riera J. , Wannemuehler M. J. 
Published: March 2003

SummaryA vaccine inducing protective immunity to a spirochaete‐induced colitis of pigs predominantly stimulates expansion of CD8+cellsin vivoand in antigen‐stimulated lymphocyte cultures. CD8+cells, however, are rarely considered necessary for protection against extracellular bacterial pathogens. In the present study, pigs recovering from colitis resulting from experimental infection withBrachyspira (Serpulina) hyodysenteriaehad increased percentages of peripheral blood CD4– CD8+(αα‐expressing) cells compared with non‐infected pigs. CD8αα+cells proliferated in antigen‐stimulated cultures of peripheral blood mononuclear cells fromB. hyodysenteriae‐vaccinated pigs. Proliferating CD8αα+cells consisted of CD4–, CD4+and γδ T‐cell receptor‐positive cells. CD4– CD8αβ+cells from vaccinated or infected pigs did not proliferate uponin vitroantigen stimulation. Of the CD8αα cells that had proliferated, flow cytometric analysis indicated that the majority of the CD4+ CD8+cells were large (i.e. lymphoblasts) whereas the CD4– CD8+cells were predominantly small. Addition of monoclonal antibodies (mAb) specific for either porcine major histocompatibility complex (MHC) class I or class II antigens diminishedB. hyodysenteriae‐specific proliferative responses whereas addition of mAb to porcine MHC II, but not porcine MHC I, reduced the CD8αα response.In vitrodepletion of CD4+cells by flow cytometric cell sorting diminished, but did not completely abrogate, the proliferative response of cells from vaccinated pigs toB. hyodysenteriaeantigen stimulation. These results suggest that CD8αα cells are involved in recovery and possibly protection from a spirochaete‐induced colitis of pigs; yet, this response appears to be partially dependent upon CD4+cells.
Convergence between CD98 and integrin‐mediated T‐lymphocyte co‐stimulation
Authors: Warren A. P. , Patel K. , Miyamoto Y. , Wygant J. N. , Woodside D. G. , Mcintyre B. W. 
Published: March 2003

SummaryCD98 is a widely expressed cell surface heterodimeric glycoprotein, which is rapidly up‐regulated upon activation of T lymphocytes. Monoclonal antibody (mAb) 80A10 recognizes an epitope on CD98 and in combination with CD3 antibody causes proliferation of peripheral blood T lymphocytes. CD98 co‐stimulatory activity, mediated by either mAb 80A10 or 4F2, a well‐characterized CD98‐specific mAb, is blocked in the presence of the soluble β1 integrin antibody 18D3. Previously we have reported that co‐stimulatory activity of antibodies to integrins α4β1, α5β1, αLβ2 and α4β7 is inhibited by 18D3, whereas co‐stimulation mediated by non‐integrins was unaffected. Thus the non‐integrin CD98 is uniquely sensitive to the inhibitory effects of β1 integrin‐blocking antibodies, which may reflect convergent signalling mechanisms between integrins and CD98. This is consistent with recent reports suggesting that CD98 may regulate integrin‐mediated adhesive events.
CpG‐oligodeoxynucleotides enhance T‐cell receptor‐triggered interferon‐γ production and up‐regulation of CD69 via induction of antigen‐presenting cell‐derived interferon type I and interleukin‐12
Authors: Kranzer K. , Bauer M. , Lipford G. B. , Heeg K. , Wagner H. , Lang R. 
Published: March 2003

SummaryBacterial cytidine–phosphate–guanosine (CpG‐DNA) activates antigen‐presenting cells (APC) and drives T helper 1 (Th1)‐polarized immune responses in the mouse. Claims have been made that CpG‐DNA costimulates murine T cells. We examined the direct and indirect effects of CpG‐oligodeoxynucleotides (CpG‐ODN) on human T‐cell activation. CpG‐ODN failed to costimulate purified human T cells activated with α‐CD3 or α‐T‐cell receptor (TCR)αβ antibodies. In contrast, CpG‐ODN sequence‐specifically caused increased expression of CD69 on CD4 and CD8 T cells when peripheral blood mononuclear cells (PBMC) were stimulated via α‐CD3. CpG‐ODN and α‐CD3 stimulation synergized to induce interferon‐γ (IFN‐γ) in T cells and natural killer (NK) cells, as shown by intracellular fluorescence‐activated cell sorter (FACS) staining. These effects of CpG‐ODN on human T cells were caused by the release of IFN type I (IFN‐I) and interleukin‐12 (IL‐12) from PBMC. Enhancement of CD69 expression on α‐CD3‐triggered T cells could be reproduced in a coculture transwell system of purified T cells and PBMC, was inhibited by neutralizing antibodies to IFN‐I and could be mimicked by adding exogenous IFN‐I. Furthermore, neutralization of either IFN‐I or IL‐12 diminished, and in combination abolished, IFN‐γ production. These findings show that CpG‐ODN potentiate TCR‐triggered activation of human T cells in an APC‐dependent manner.
Native IgG2ab is barely antigenic to major histocompatibility complexclass II‐restricted T cells owing to inefficient internalization by professionalantigen‐presenting cells
Authors: Bartnes K. , Hannestad K. 
Published: March 2003

SummaryPeptide epitopes derived from immunoglobulin variable regions represent tumour‐specific antigens on B‐cell neoplasms and can be recognized by syngeneic, major histocompatibility complex (MHC) class II‐restricted T cells. Immunoglobulin peptide/MHC class II complexes may also be involved in autoimmunity and CD4+ T‐cell‐mediated B‐cell regulation. Thus, the IgG2ab H‐chain allopeptide γ2ab 435–451 presented on I‐Ad mimics the epitope implicated in herpes simplex virus‐induced autoimmune stromal keratitis and is the target of T helper 1 (Th1) clones that suppress IgG2ab production in vivo. We here report that spleen and thymus cells constitutively present the autologous γ2ab epitope to a γ2ab 435–451/I‐Ad reactive T‐cell hybridoma as a function of the animal housing conditions (specific pathogen‐free or not) and the serum levels of IgG2ab. Constitutive presentation in the spleen was predominantly performed by dendritic cells. Whereas spleen cells poorly presented native IgG2ab to a γ2ab 435–451/I‐Ad reactive T‐cell hybridoma, IgG2ab in the form of immune complexes were presented > 200‐fold more efficiently owing to internalization via low‐affinity FcγR on macrophages. The antigenicity could also be improved by homotypic aggregation and by targeting IgG2ab to complement receptors on the A20 B‐cell lymphoma. Mice without detectable IgG2ab‐containing immune complexes typically exhibited minimal constitutive presentation. Nevertheless, native IgG2ab can sensitize antigen‐presenting cells in vivo, as mice that were devoid of immune complexes and carried an IgG2ab‐producing tumour did present constitutively, even at physiological IgG2ab serum levels. Whereas the amounts of IgG released from most B‐cell lymphomas may be too low to allow spontaneous priming of tumour‐specific MHC class II‐restricted T cells, administration of tumour immunoglobulin in aggregated form might improve the efficacy of idiotype vaccination.
Chronic restraint stress induces severe disruption of the T‐cell specific response to tetanus toxin vaccine
Authors: Tournier J.‐ N. , Mathieu J. , Mailfert Y. , Multon E. , Drouet C. , Jouan A. , Drouet E. 
Published: March 2003

SummaryChronic stress is known to induce immunological disorders. In the present study we examined the consequences of chronic restraint stress on the immune response to tetanus toxin in mice. We investigated the repartition of subsets of lymphoid cells in blood and spleen, the functional ability of lymphocytes to proliferate and to produce cytokines, and antibody titres against tetanus toxin following stress. We report discordance of the stimulation index of lymphocytes in the restraint group: the proliferating rate severely decreased following stimulation with a relevant antigen, whereas it increased with mitogen. Thus, we report a decrease in cytokine production with relevant antigen (interferon‐γ and interleukin‐10), without a T helper type 1 and 2 secretion imbalance. Moreover, we observed an alteration in the humoral response, including a delay in isotype maturation and an immunoglobulin G1/G2a imbalance.
Analysis of recombinant mycobacteria as T helper type 1 vaccines in an allergy challenge model
Authors: Janssen R. , Kruisselbrink A. , Hoogteijling L. , Lamb J. R. , Young D. B. , Thole J. E. R. 
Published: March 2003

SummaryThe potential for development of mycobacteria as T helper type 1 (Th1) vaccines capable of induction of Th1 responses to recombinant antigens was explored in a model system based on an immunodominant peptide from house dust mite. Different recombinant mycobacterial preparations were compared for their ability to induce a Th1 response to the peptidea. It was found that mycobacterial viability was not a prerequisite for Th1 immunogenicity. A dominant interferon‐γ (IFN‐γ) response to peptide was observed in splenocytes from C57BL/6J mice immunized with live or heat‐killed preparations of recombinant Mycobacterium vaccae or with live attenuated bacillus Calmette–Guèrin (BCG) vaccine expressing the antigen. Interleukin‐5 (IL‐5), a marker of a Th2 response, was detected only in mice receiving live M. vaccae. A similar pattern was observed in BALB/b mice, although the magnitude of the IFN‐γ response was much lower. Control and immunized mice were subsequently exposed to allergen using a Th2‐inducing challenge protocol. A significant shift from a Th2 to a Th1 response was observed in immunized mice, as judged by cytokine expression by splenocytes and by subclass of circulating antibody. The effect was seen in three inbred mouse strains differing in their innate bias towards Th1 or Th2 responses. It was dependent on the presence of specific antigen in the mycobacterial preparation and, under the immunization conditions tested, was more pronounced with dead M. vaccae than with live BCG as carrier vaccine. The results demonstrate the potency of killed mycobacteria as Th1 adjuvants and suggest a potential application for recombinant mycobacteria in antigen‐specific immune modulation.
Characterization of self‐T‐cell response and antigenic determinants of U1A protein with bone marrow‐derived dendritic cells in NZB × NZW F1 mice
Authors: Suen Jau‐Ling , Wu Chung‐Hsiun , Chen Ying‐Yu , Wu Wen‐Mein , Chiang Bor‐Luen 
Published: March 2003

SummarySystemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies directed against nuclear intact structures, such as nucleosomes and small nuclear ribonucleoproteins (snRNPs). Autoantibodies against snRNPs are of special interest because they are detectable in the majority of SLE patients. Although the B‐cell antigenic determinants have been well characterized, very limited data have been reported in regard to the T‐cell epitopes of snRNPs. Furthermore, several studies have demonstrated that determination of the auto‐T‐cell epitopes recognized by freshly isolated T cells is difficult from unprimed lupus mice when self‐antigen‐pulsed B cells or macrophages are used as antigen‐presenting cells (APCs) in vitro. In the present study, we showed a novel approach for determining the auto‐T‐cell epitopes, using bone marrow‐derived dendritic cells (BMDCs) pulsed with the murine U1A protein – an immunodominant antigen of the U1 snRNPs – which is capable of activating freshly isolated T cells from unprimed (NZB × NZW) F1 (BWF1) mice in vitro. The T‐cell epitope area was found to be located at the C‐terminus of U1A, overlapping the T‐cell epitope of human U1A that has been reported in human SLE. Identification of the autoreactive T‐cell epitope(s) in snRNPs will help to elucidate how reciprocal T–B determinant spreading of snRNPs emerges in lupus. The results presented here also indicate that it is feasible to use this approach to further explore strategies to design immunotherapy for patients with lupus.
Grass pollen immunotherapy for hayfever is associated with increases in local nasal but not peripheral Th1 : Th2 cytokine ratios
Authors: Wachholz Petra A. , Nouri‐Aria Kayhan T. , Wilson Duncan R. , Walker Samantha M. , Verhoef Adrienne , Till Stephen J. , Durham Stephen R. 
Published: March 2003

SummaryGrass pollen immunotherapy is the only treatment for hayfever that is both effective and confers long‐term benefit. Immunotherapy may act by altering the local nasal mucosal T helper type 2 (Th2) to type 1 (Th1) cytokine balance either by down‐regulation and/or immune deviation of T‐lymphocyte responses. There is controversy as to whether these changes are detectable in peripheral blood. We therefore examined both local nasal and peripheral T‐cell responses to allergen exposure in the same subjects before and after immunotherapy. In a double‐blind trial of grass pollen immunotherapy, nasal biopsies were obtained at baseline and during the peak pollen season following 2 years of immunotherapy. Placebo‐treated patients showed a seasonal increase in CD3+ T cells (P = 0·02) and in interleukin‐5 (IL‐5) mRNA+ cells (P = 0·03) and no change in interferon‐γ (IFN‐γ ) mRNA+ cells (P = 0·2) in the nasal mucosa. In contrast, in the immunotherapy‐treated group, there were no changes in the number of CD3+ T cells (P = 0·3) and IL‐5 mRNA+ cells (P = 0·2) but a significant increase in the number of IFN‐γ mRNA+ cells (P = 0·03). Furthermore, clinical improvement in the immunotherapy‐treated group was accompanied by a seasonal increase in the ratio of IFN‐γ to IL‐5 mRNA+ cells in the nasal mucosa (P = 0·03). In contrast, there were no significant changes in peripheral T‐cell proliferative responses or cytokine production for IFN‐γ or IL‐5 in response to grass pollen either within or between the two treatment groups. We conclude that successful grass pollen immunotherapy was associated with an increase in the ratio of IFN‐γ to IL‐5 mRNA+ cells in the nasal mucosa, whereas these changes were not reflected by alterations in peripheral blood T‐cell proliferative responses or cytokine production before/after treatment.