bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human antigen‐presenting cell/tumour cell hybrids stimulate strong allogeneic responses and present tumour‐associated antigens to cytotoxic T cells in vitro
Authors: Dunnion D. J. , Cywinski A. L. , Tucker V. C. , Murray A. K. , Rickinson A. B. , Coulie P. , Browning M. J. 
Published: March 2003

SummaryMost tumours do not stimulate effective antitumour immune responses in vivo. In order to enhance the immunogenicity of human tumour cells, we fused a variety of tumour cell lines with an Epstein–Barr virus transformed B‐lymphoblastoid cell line (EBV B‐LCL) in vitro, to produce stable hybrid cells. Hybrid cell lines showed a marked increase in their ability to stimulate primary allogeneic T‐cell responses in vitro, as compared with the parent tumour cells. The hybrid cells induced proliferation of naive (CD45RA+) as well as memory (CD45RO+) T lymphocytes, and both CD4+ and CD8+ subpopulations of T cells were directly stimulated. The stimulatory hybrids expressed human leucocyte antigen (HLA) class I and II, and a wide range of surface accessory molecules, including the T‐cell co‐stimulatory ligand molecules CD40, CD80 (B7.1) and CD86 (B7.2), the expression of which was required for optimal stimulation of T‐cell responses. Fusion of the EBVB‐LCL with a melanoma cell line (518.A2) yielded hybrid cells that expressed the melanoma‐associated antigens MAGE‐1 and MAGE‐3, and presented these antigens to antigen‐specific, HLA class I‐restricted cytotoxic T‐lymphocyte clones with greater efficiency than the parent melanoma cell line. These findings suggest that the generation of human antigen‐presenting cell/tumour cell hybrids offers promise as an approach to cancer immunotherapy.
Systematic characterization of porcine ileal Peyer's patch, I. Apoptosis‐sensitive immature B cells are the predominant cell type
Authors: Andersen J. K. , Takamatsu H. , Oura C. A. L. , Brookes S. M. , Pullen L. , Parkhouse R. E. M. 
Published: March 2003

SummaryIt is now apparent that the Peyer's patches of some species exhibit structural, functional and developmental heterogeneity. In sheep, for example, the ileal Peyer's patch (IPP) is the primary, antigen‐independent site for the generation of the primary immunoglobulin repertoire and consequent production of the systemic B‐cell pool. The pig has three distinct Peyer's patches, including an IPP, but the functional status of this organ, as primary or secondary lymphoid tissue, is not clear. Here, we have systematically characterized pig IPP follicular lymphocytes and show that about 90% B cells that are positive for surface immunoglobulin G (sIgM+) and express an immature phenotype characterized by expression of myeloid marker sWC3 (74‐22‐15) and two molecules recognized by IPP B‐cell‐specific monoclonal antibodies (F10/4, F12/35). Extensive apoptosisin vivoandin vitrowas demonstrated by electron microscopy, immunohistology with TdT‐mediated dUTP nick end labelling, DNA analysis and fluorescence‐activated cell sorter analysis. Thus, when isolated IPP follicular cells were incubated at 37°in vitro, the majority of them became apoptotic. The few that survived, however, had lost their expression of sWC3, F10/4, F12/35, but showed an increased expression of sIgM and major histocompatibility complex class II indicating that such surviving cells were of a more mature phenotype. Although more T cells were observed in porcine IPP follicles than in sheep IPP, CD3+cells comprised less than 5% of the IPP follicular lymphocytes. Thus, the results clearly indicate that pig IPP is equivalent to sheep IPP.
Systematic characterization of porcine ileal Peyer’s patch, II. A role for CD154 on T cells in the positive selection of immature porcine ileal Peyer’s patch B cells
Authors: Andersen J. K. , Takamatsu H. , Pullen L. , Parkhouse R. M. E. 
Published: March 2003

SummaryWe previously demonstrated that the majority (≥ 90%) of porcine ileal Peyer’s patch (IPP) follicular cells are immature B cells destined to die by apoptosis, when incubated at 37°. In this paper we approached the mechanisms responsible for positive selection of porcine IPP follicular immature B‐cell selection, by screening for various cell types, cytokines and polyclonal and monoclonal antibodies for promoting the survival of IPP B cells. Of these reagents, only CD3 cross‐linked purified T cells from mesenteric lymph nodes were able to rescue IPP follicular B cells from apoptosis, although polyclonal anti‐IPP lymphocyte antibodies delayed apoptosis. This survival effect could be reproduced simply by incubating IPP follicular B cells with soluble and cell membrane‐expressed CD154, an observation consistent with the demonstrated presence of CD40 and CD154 on porcine IPP follicular B cells and activated T cells, respectively. The IPP follicular B cells rescued in this manner expressed a more mature surface marker phenotype. Immunohistology and fluorescence‐activated cell sorter analysis demonstrated that subpopulations of IPP follicular T cells (less than 0·5%) express CD154. Thus, perhaps unexpectedly, CD154 on T cells may play a role in the positive selection of immature B cells in the porcine IPP. The origin and control of the activated T cells identified within the porcine IPP remains to be investigated.
CD1d structure and regulation on human thymocytes, peripheral blood T cells,B cells and monocytes
Authors: Exley M. , Garcia J. , Wilson S. B. , Spada F. , Gerdes D. , Tahir S. M. A. , Patton K. T. , Blumberg¶ R. S. , Porcelli S. , Chott** A. , Balk S. P. 
Published: March 2003

SummaryHuman T cells expressing CD161 and an invariant T‐cell receptor (TCR) α‐chain (Vα24invt T cells) specifically recognize CD1d and appear to have immunoregulatory functions. However, the physiological target cells for this T‐cell population, and whether alterations in CD1d expression contribute to the regulation of Vα24invt T‐cell responses, remain to be determined. A series of antibodies were generated to assess CD1d expression, structure and regulation on human lymphoid and myeloid cells. CD1d was expressed at high levels by human cortical thymocytes and immunoprecipitation analyses showed it to be a 48 000‐MW glycosylated protein. However, after solubilization, the majority of the thymocyte CD1d protein, but not CD1d expressed by transfected cells, lost reactivity with monoclonal antibodies (mAbs) against native CD1d, indicating that it was alternatively processed. Moreover, thymocytes were not recognized by CD1d‐reactive Vα24invt T‐cell clones. Medullary thymocytes and resting peripheral blood T cells were CD1d–, but low‐level CD1d expression was induced on activated T cells. CD1d was expressed by B cells in peripheral blood and lymph node mantle zones, but germinal centres were CD1d–. Resting monocytes were CD1d+ but, in contrast to CD1a, b and c, their surface expression of CD1d was not up‐regulated by granulocyte–macrophage colony‐stimulating factor (GM‐CSF) and interleukin‐4 (IL‐4) activation. These results demonstrate constitutive CD1d expression by human professional antigen‐presenting cells and that post‐translational processing of CD1d may contribute to regulation of the activity of CD1d‐specific T cells.
The role of complement in the acquired immune response
Authors: Nielsen C. H. , Fischer E. M. , Leslie R. G. Q. 
Published: March 2003

SummaryStudies over the past three decades have clearly established a central role for complement in the promotion of a humoral immune response. The primary function of complement, in this regard, is to opsonize antigen or immune complexes for uptake by complement receptor type 2 (CR2, CD21) expressed on B cells, follicular dendritic cells (FDC) and some T cells. A variety of mechanisms appear to be involved in complement‐mediated promotion of the humoral response. These include: enhancement of antigen (Ag) uptake and processing by both Ag‐specific and non‐specific B cells for presentation to specific T cells; the activation of a CD21/CD19 complex‐mediated signalling pathway in B cells, which provides a stimulus synergistic to that induced by antigen interaction with the B‐cell receptor (BCR); and promotion of the interaction between B cells and FDC, where C3d‐bearing immune complexes participate in intercellular bridging. Finally, current studies suggest that CR2 may also play a role in the determination of B‐cell tolerance towards self‐antigens and thereby hold the key to the previously observed correlation between deficiencies of the early complement components and autoimmune disease.
Evidence for a unique expression of CD4 on murine vaginal CD4+ cells
Authors: Wormley Jr F. L. , Scott M. , Luo W. , Baker M. , Chaiban J. , Fidel Jr P. L. 
Published: March 2003

SummaryMucosal cell‐mediated immunity (CMI) by CD4+ T cells is postulated to be important for host defence against several vaginal pathogens. In addition to the recognized phenotypic distinctions of resident vaginal T lymphocytes, we recently provided evidence by fluorescence‐activated cell sorter (FACS) that murine vaginal CD4+ T lymphocytes, are differentially recognized by two epitope‐distinct anti‐CD4 antibodies, suggesting that the CD4 protein on vaginal CD4+ cells is atypically expressed. In the present study, we confirm this by FACS and immunohistochemistry under non‐denaturing conditions using two additional anti‐CD4 antibodies. However, positive immunohistochemical staining of vaginal CD4+ cells under denaturing conditions revealed that the CD4 epitope in question is indeed present within the CD4 protein. Using reverse transcription polymerase chain reaction, amplification of CD3, T‐cell receptor‐β (TCR‐β), and TCR‐δ mRNA from lymph node and vaginal tissue, and CD4 mRNA from lymph node tissue was demonstrable. In contrast, amplification of CD4 mRNA from vaginal tissue, vaginal enriched lymphoid cells, or a purified (FACS‐sorted) population of vaginal‐specific CD4+ cells using two distinct primer sets was not demonstrable. Altogether, our results provide evidence that the CD4 protein on vaginal CD4+ T cells is conformationally distinct compared with its systemic counterpart, either as a result of a unique CD4 mRNA sequence or from a stable interaction of soluble CD4 with the surface of vaginal T cells.
Adrenaline inhibits macrophage nitric oxide production through β1 and β2 adrenergic receptors
Authors: Sigola L. B. , Zinyama & R. B. 
Published: March 2003

SummaryThis study was conducted to investigate the role of the acute stress hormone adrenaline on macrophage nitric oxide (NO) production. Murine peritoneal macrophages were stimulated in vitro with lipopolysaccharide (LPS) in the absence or presence of adrenaline. Adrenaline inhibited the LPS‐induced nitrite response in a dose‐dependent manner. The suppressive effect of adrenaline on NO production was mediated via β1 and β2 adrenergic receptors since isoprenaline (a non‐selective β1 and β2 agonist), dobutamine and salbutamol (selective β1 and β2 agonists, respectively) had similar effects on the NO response. In addition, the inhibitory effect of adrenaline on NO was abrogated by both propranolol (a non‐specific β blocker) and atenolol (a specific β1 inhibitor). In contrast to β receptor activation, the α adrenergic agonist phenylephrine had no effect on the LPS NO response, and furthermore, phentolamine (an α receptor antagonist) did not ameliorate adrenaline’s inhibitory action.
Mouse xenoantigens contribute to rat T‐cell Vβ repertoire generation in mixed xenogeneic bone marrow chimeras
Authors: Huang Y. , Ildstad S. T. , Neipp M. , Shirwan H. 
Published: March 2003

SummaryWe previously demonstrated that rat bone‐marrow‐derived cells in mixed xenogeneic chimeras (rat + mouse → mouse) contribute to peripheral selection of mouse T‐cell receptor (TCR) variable βs (Vβs) repertoire. In this study, we analysed rat T cells that developed in the chimeras to assess the contribution of mouse xenoantigens to the development of rat TCR repertoire. The expression of rat Vβs was analysed using flow cytometry and a reverse transcription–polymerase chain reaction (RT–PCR) method that allows for both semiquantitative analysis of rat Vβ gene expression and size heterogeneity of the complementarity determining region 3 (CDR3) domain. Three distinct patterns of Vβ expression were detected. Partial deletion was observed for Vβ5, 7, 12, 14, 16, 17 and 20 that exhibited reduced levels of peripheral expression by 3·4‐, 1·8‐, 8·7‐, 2·0‐, 7·8‐, 9·5‐ and 1·8‐fold, respectively, compared with the levels of Vβs in naïve rats. Higher levels of peripheral expression were detected for three rat Vβ genes; Vβ6 (2·2‐fold), Vβ8·2 (3·2‐fold), and Vβ9 (1·7‐fold). The relative expression of the other 10 known rat Vβ families in chimeras was unchanged as compared with that of normal rats. We did not observe detectable changes in the pattern of CDR3 expression in chimeras, suggesting that the mouse xenogeneic environment exerted its influence on the development of rat T cells via the Vβ‐encoded CDR1/2 domains. Our data demonstrate that the rat T‐cell repertoire in chimeras is shaped by both contractions as well as expansions of selected Vβs and suggest that mouse xenoantigens and/or superantigens of endogenous mouse retroviruses may contribute as ligands for these selection processes
Characterization of CD4– CD8– CD3+ T‐cell receptor‐αβ+ T cells in murine cytomegalovirus infection
Authors: Hossain M. S. , Takimoto H. , Ninomiya T. , Yoshida H. , Kishihara K. , Matsuzaki G. , Kimura G. , Nomoto K. 
Published: March 2003

SummaryIn this study, we have investigated that after the intraperitoneal infection with murine cytomegalovirus (MCMV), the CD3+ CD4– CD8–(double negative; DN) T‐cell receptor (TCR)αβ+ T cells increased in peritoneal cavity, liver and spleen in both resistant C57BL/6 and susceptible BALB/c mice. The total cellular population of these cells showed peak levels around day 5 after infection in all the three investigated organs and the following phenotypical and functional characteristics emerged. The peritoneal DN TCRαβ+ T cells expressed highly skewed TCRVβ8 on day 5 after infection compared with the uninfected mice, but those in spleen and liver showed moderate and low skewed TCRVβ8, respectively. The percentages of NK1.1+ DN TCRαβ+ T cells gradually decreased as did modulation of some of their activation markers consistent with an activated cell phenotype. The peritoneal DN TCRαβ+ T cells on day 5 after infection expressed the genes of interferon‐γ (IFN‐γ), tumour necrosis factor‐α, Eta‐1 (early T‐cell activation‐1) and MCP‐1 (monocyte chemoattractant protein 1) but lacked expression of interleukin‐4 (IL‐4). After in vitro stimulation with phorbol 12‐myristate 13‐acetate and calcium ionophore in the presence of Brefeldin A, higher frequencies of intracellular IFN‐γ+ DN TCRαβ+ T cells were detected in all three investigated organs of infected mice compared with those of uninfected mice. Stimulation of peritoneal DN TCRαβ+ T cells with plate‐bound anti‐TCRβ monoclonal antibodies showed proliferation and also produced IFN‐γ but not IL‐4. These results suggest that DN TCRαβ+ T cells were activated and may have an antiviral effect through producing IFN‐γ and some macrophage‐activating factors during an early phase of MCMV infection.
Immunity to vaginal herpes simplex virus‐2 infection in B‐cell knockout mice
Authors: Parr M. B. , Parr E. L. 
Published: March 2003

SUMMARYWe investigated the involvement of antibody in protection against vaginal herpes simplex virus type‐2 (HSV‐2) infection by comparing intact and B‐cell knockout (KO) mice. Vaginal immunization of intact mice with attenuated HSV‐2 markedly reduced an HSV‐2 challenge infection in the vagina. In contrast, immunization of B‐cell KO mice produced less immunity against the challenge infection and that immunity occurred in a different pattern. At 20 hr after challenge, immunostaining of virus proteins in the vaginal epithelium and shed virus protein titres in the vaginal secretions were not significantly different between immunized and non‐immunized B‐cell KO mice and were much greater than in immunized intact mice. At 48 hr after challenge, the vaginal infection in immunized B‐cell KO mice was markedly less than at 20 hr but remained ≈ sevenfold higher than in intact mice. This pattern of challenge infection in the vagina indicates that B cells, and probably the antibody derived from them, provided significant protection against reinfection in intact mice, especially during the first 20 hr after challenge, while other effector mechanisms became important between 20 and 48 hr after challenge. To determine whether T‐cell immunity in immunized B‐cell KO mice was equal to that in intact mice, we assessed interferon‐γ (IFN‐γ) secretion by memory T cells in vivo in the vagina at 20 hr after challenge. We found no significant differences in the up‐regulation of major histocompatibility complex (MHC) class II antigens in the epithelium, up‐regulation of vascular cell adhesion molecule‐1 (VCAM‐1) in vascular endothelium, or recruitment of T cells to the mucosa, indicating that the memory T‐cell response to virus challenge was the same in intact and B‐cell KO mice.
Calcitonin gene‐related peptide inhibits lipopolysaccharide‐induced interleukin‐12 release from mouse peritoneal macrophages, mediated by the cAMP pathway
Authors: Liu J. , Chen M. , Wang X. 
Published: March 2003

SummaryPreviously we showed that calcitonin gene‐related peptide (CGRP), a neuropeptide, inhibited lipopolysaccharide (LPS)‐induced tumour necrosis factor‐α (TNF‐α) production and increased interleukin (IL)‐6 release at low concentrations via activation of the cAMP pathway in mouse peritoneal macrophages (Mφ). In this study we examined whether CGRP could modulate IL‐12 release from mouse peritoneal Mφ, and if so, what signal transduction pathway was involved. Mφ were obtained from the peritoneal exudate of male BALB/c mice. The cells were plated on culture dishes at a density of 5 × 105 cells per well and allowed to adhere for 2 hr. After incubation for 24 hr, the Mφ were cultured with 0·1 µg/ml of LPS, alone or together with CGRP (1–1000 n
m) for 24 hr. The amount of IL‐12 in the cell medium was measured by enzyme‐linked immunosorbent assay (ELISA). The results showed that CGRP attenuated LPS‐induced IL‐12 release in a concentration‐dependent manner. Production of IL‐12 was decreased from 95·9 ± 4·6 to 73·4 ± 5·7 pg/ml by 100 n
m CGRP. The two cAMP phosphodiesterase (PDE) inhibitors, 3‐isobutyl‐1‐methyl‐xanthine (IBMX) and rolipram, significantly potentiated the CGRP response, and the level of IL‐12 was further decreased by 28% and 47%, respectively. However, CGRP had no effect on IL‐12 production from unstimulated Mφ. The LPS‐induced IL‐12 release from Mφ could also be reduced by forskolin, an activator of adenylate cyclase, and 8‐Br‐cAMP, an analogue of cAMP. Using the reverse transcription–polymerase chain reaction (RT–PCR), we found that CGRP also decreased the LPS‐induced IL‐12 p40 mRNA levels. Furthermore, pretreatment with H89 (0·1 µm or 1 µm), an inhibitor of cAMP‐dependent protein kinase, diminished CGRP effects, IL‐12 production and gene expression. These data suggest that LPS‐induced IL‐12 release and gene expression were attenuated by CGRP via an activated cAMP‐protein kinase A (PKA) pathway in mouse peritoneal Mφ.
Genetically detoxified mutants of heat‐labile enterotoxin from Escherichia coli are effective adjuvants for induction of cytotoxic T‐cell responses against HIV‐1 gag‐p55
Authors: Neidleman J. A. , Vajdy M. , Ugozzoli M. , Ott G. , O'hagan D. 
Published: March 2003

SummaryThere is an urgent need for prophylactic and therapeutic vaccines against human immunodeficiency virus (HIV). Mucosal immunization strategies have great potential to elicit both mucosal and systemic cellular immunity required to protect against HIV‐induced aquired immune deficiency syndrome (AIDS). However, mucosal immunizations with soluble protein antigens generally require adjuvants. In this study, we tested two mutants of the heat‐labile enterotoxin (LT) from Escherichia coli, LTK63: with no measurable ADP‐ribosyltransferase activity, and LTR72: with residual ADP‐ribosyltransferase activity, as mucosal adjuvants for induction of cytotoxic T lymphocyte (CTL) responses to coadministered HIV gag p55 protein. We found that intranasal (i.n.) immunizations with HIV gag p55 protein coadministered with LTK63 or LTR72 induced systemic CTL responses comparable to that obtained following intramuscular (i.m.) immunizations with the same adjuvants. Moreover, oral coadministration of LTR72, but not LTK63, resulted in local as well as systemic p55‐specific CTL responses in mesenteric lymph nodes (MLN) and spleens (SP) of the immunized mice. These data have important implications for current efforts to develop a safe vaccine against HIV.
Natural killer cell‐dependent immunoglobulin G2a anti‐bovine serum albumin (BSA) response elicited by high molecular weight dextran–BSA conjugates associated with dextran‐mediated macrophage–natural killer cell interaction
Authors: Ediriwickrema C. P. , Tonkonogy S. L. , Hammerberg B. 
Published: March 2003

SummaryThe roles of the interferon‐γ (IFN‐γ) and interleukin‐12 (IL‐12) produced during natural killer (NK) cell interaction with macrophages (Mφ) were investigated as the basis for the induction of immunoglobulin G2a (IgG2a) anti‐bovine serum albumin (BSA) responses by high molecular weight dextran conjugated to BSA (HMW‐DEX–BSA). BALB/c mice immunized with HMW‐DEX–BSA produced significantly higher levels of both IgG1 and IgG2a anti‐BSA than did mice immunized with BSA alone. Both IgG1 and IgG2a anti‐BSA levels were higher in mice immunized with BSA conjugated to dextran of molecular weight (MW) 5 000 000–40 000 000 compared with dextran of MW 10 000–60 000. The enhancement of anti‐BSA IgG2a levels but not of anti‐BSA IgG1 levels was inhibited when free BSA was added to the HMW‐DEX–BSA conjugate. NK cell depletion during HMW‐DEX–BSA immunization of mice resulted in significantly lower anti‐BSA IgG2a levels without affecting anti‐BSA IgG1 levels. Naive splenocytes or Mφ + NK cell co‐cultures incubated with HMW‐DEX or HMW‐DEX–BSA produced higher IFN‐γ levels than splenocytes or co‐cultures incubated with BSA alone. HMW‐DEX stimulated both IFN‐γ and IL‐12 production by Mφ + NK cell co‐cultures in a dose‐dependent manner. DEX‐induced IFN‐γ production by NK cells was dependent upon the presence of IL‐12, and IL‐12 production by Mφ was dependent upon the presence of IFN‐γ in these co‐cultures. Both Mφ and NK cells bound DEX to their surfaces. These data demonstrate that BSA linked to HMW‐DEX enhanced both T‐helper‐1‐ and T‐helper‐2‐associated antibody responses to BSA. The results also indicate an IL‐12‐dependent positive feedback interaction between NK cells and Mφ that supports a NK cell/IFN‐γ‐dependent mechanism for enhancement of anti‐BSA IgG2a antibody responses in mice immunized with HMW‐DEX–BSA protein conjugates.