bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particulate antigens may be reprocessed after initial phagocytosis for presentation to T cells in vivo
Authors: Wright MD , Wood PR , Coia G , Cheers C 
Published: July 2007

SummaryMacrophages were pulsed with Listeria monocytogenes antigens by intraperitoneal injection prior to harvesting and thoroughly washing the cells. The pulsed macrophages were injected into the feet of Listeria‐immune or naive mice to elicit a delayed hypersensitivity reaction. Where soluble Listeria antigen was used, presentation by donor macrophages to host T cells required identity within the I region of the H‐2 complex. However, presentation of alcohol‐killed Listeria organisms or of a living, temperature‐sensitive mutant of Listeria was apparently not H‐2 restricted. When T cells enriched in vitro for Listeria reactivity were injected into the feet of naive mice, they reacted in an H‐2 restricted manner to antigen presented to them either by the pulsed macrophages or host cells apparently acquiring antigen from the original pulsed macrophages.
Festschrift Somatic mutations in B lymphocytes: New perspectives in tolerance research?
Authors: Nossal GJV 
Published: July 2007

SummaryThis paper extends the concept of clonal anergy developed in the author's laboratory. It has been shown that the primary population of B lymphocytes induced into clonal expansion and IgM antibody formation by mitogens contains many cells capable of autoantibody synthesis, but the affinity of binding to the self constituents, or indeed to foreign antigens, is low. The creation of high affinity antibody, which will still register strongly in an ELISA as an IgG molecule, demands not only the addition of lymphokines to cause isotype switching, but also intentional immunization of the donor mice to permit mutations in V region genes and selection of higher affinity B memory cells. This process appears to begin about 6 days after in vivo immunization.It is postulated that these mutational events occur primarily in germinal centres, and that there must be mechanisms to prevent escape of cells which, by chance, mutate not to higher affinity against an immunogen, but to higher affinity against a self constituent. If such mutants were allowed to enter the long‐lived, recirculating pool of B lymphocytes, they might pose a graver threat of autoimmune disease than the low‐affinity anti‐self cells of the primary repertoire. Therefore, it is suggested that recently mutated germinal centre B cells represent a pool of ‘pre‐memory’ cells, which are immature in the sense of displaying the same kind of sensitivity to negative signalling by antigen that immature B cells from newborn spleen or adult bone marrow display. If so, then the earliest phases of memory generation represent a second window of opportunity for tolerance induction within the B lymphocyte compartment.
Isolation and characterization of glomerular macrophages in experimental glomerulonephritis
Authors: Tipping PG , Holdsworth SR 
Published: July 2007

SummaryAdherent cells emigrating from glomeruli of rabbits developing anti‐glomerular basement membrane antibody induced glomerulonephritis were isolated and characterized as macrophages. Glomeruli were isolated using a sterile graded sieving technique and cultured in plastic tissue culture flasks. After varying culture times, emigrating adherent cells were harvested by ‘cold shock’ or trypsin‐versene. These cells had the morphological and functional characteristics of macrophages. They were largely mononuclear, esterase‐positive, phagocytic cells, which exhibited surface Fc receptors. A mean of 4·8±2·1 × 104 macrophages could be isolated from 2 × 104 glomeruli after 1 h in tissue culture. Greater numbers of macrophages could be isolated with further time in culture. After 72 h however, intrinsic glomerular cell contamination occurred. The majority of the cells were viable by fluorescein diacetate hydrolysis, and Trypan Blue exclusion. Further functional studies of these cells may provide some new insights into the cellular basis of macrophage‐induced glomerular injury in experimental glomerulonephritis
Role of the CD21 antigen in lymphocyte transformation by Epstein‐Barr virus
Authors: Boyd Andrew W , Fecondo John 
Published: July 2007

SummaryThe human CD21 membrane antigen has been shown to bind Epstein‐Barr Virus (EBV) and some binding and functional data imply a role for this interaction in the B cell tropism of EBV. In this report the technique of limit dilution analysis was used to provide evidence that B cell transformation by EBV only occurred when CD21 antigen was present and that all cells expressing CD21 were transformation‐competent. The rate of transformation varied, being increased if B cells were activated by an additional B cell mitogen, and being dependent on, although not strictly proportional to, the intensity of CD21 expression. The possibility that EBV might enter by other means was examined by selectively deleting CD21 antigen from the cell surface. This was accompanied by a profound decrease in the transformation frequency. It is concluded that CD21 antigen is necessary for EBV transformation and that CD21 expression is the major limiting factor in these events.
Auto‐anti‐idiotypic antibodies in mice hyperimmunized with a chemically induced bladder carcinoma
Authors: Greer Judith M , Halliday WJ 
Published: July 2007

SummaryPurified immunoglobulin from the serum of mice hyperimmunized with syngeneic tumour cells was compared with a monoclonal anti‐idiotope antibody, obtained by immunizing mice with antibody to the same tumour. Both the immunoglobulin and the monoclonal antibody were specifically immunogenic in syngeneic (BALB/c) mice as tested by in vitro and in vivo assays of cell‐mediated immunity. In both cases the reactivity was absent in immunoglobulin heavy chain gene complex‐1 ‐(Igh) allotype congenic (CB.20) mice, indicating Igh‐restriction of immunogenicity. The active material in hyperimmune serum thus has the properties of auto‐anti‐idiotypic antibody, complementary to T cell idiotopes.
B lymphocyte/carcinoma antigen (BLCa): Functional study in B cells
Authors: Zola H , Barclay S , Furness V , Macardle PJ , Neoh SH , Bradley J 
Published: July 2007

SummaryBLCa is an antigen expressed on the surface of B lymphocytes and certain carcinomas. In this study we have demonstrated that BLCa is distinct from known B cell antigens classified by ‘clusters of differentiation’ (CD). In particular, the monoclonal antibody MA6, which identifies BLCa, can be distinguished from antibodies of the CDw40 group, which detect an antigen of similar molecular weight expressed also on B cells and certain carcinomas. The expression of BLCa on B cells was measured as tonsil B cells were activated (by anti‐Ig and interleukin‐4 (IL‐4)), induced to proliferate (by low molecular weight B Cell Growth Factor (LMW‐BCGF). and induced to differentiate (by B Cell Differentiation Factor, BCDF). Expression of BLCa increased in response to LMW‐BCGF, The effect of inclusion of MA6 antibody in cultures with the B cell stimuli was also investigated. MA6 showed an anti‐proliferative effect which was antibody‐dose dependent, but did not otherwise inhibit or co‐operate with anti‐Ig, IL‐4, LMW‐BCGF or BCDF.
Evidence that Thy‐1 and Ly‐5 (T‐200) antigens interact with sulphated carbohydrates
Authors: Parish Christopher R , Hogarth P Mark , McKenzie Ian FC 
Published: July 2007

SummaryRecent studies have demonstrated that lymphocytes express an array of ceil surface receptors for sulphated polysaccharides (SP). Experiments were undertaken to determine the binding characteristics of these receptors and establish whether any known lymphocyte cell surface antigens interact with sulphated carbohydrates. It was found that murine thymocytes lack receptors for chondroitin‐4‐sulphate but express saturable, high affinity binding sites for heparin, fucoidan and dextran sulphate, with an apparent affinity constant range of 0·03–2·6 ×10−9 mol/l. Binding inhibition experiments revealed one class of binding sites on murine thymocytes that is shared by heparin, fucoidan and dextran sulphate and another class of sites that is dextran sulphate‐specific.The cell surface receptors for the SP were affinity‐purified by applying detergent lysates of 125I‐labelled thymocyte membranes to SP‐coupled solid supports. It was found that the Thy‐1 and Ly‐5 (T‐200 or leucocyte common antigen) molecules of murine thymocytes bind to sulphated carbohydrates, although the two molecules differed substantially in their reactivity with the four different SP tested. Furthermore, only subpopulations of the Thy‐1 and Ly‐5 molecules interacted with sulphated sugars. Four additional sulphated carbohydrate‐binding molecules were also detected. It is suggested that the SP‐binding molecules are involved in the interaction of lymphocytes with glycosaminoglycans on other cells and in the interstitial space.
Augmentation of mitogen‐induced thymocyte proliferation by bacterial products is mediated by an Mr 36 000 monokine
Authors: Hedberg Nancy , Hunter Neil 
Published: July 2007

SummaryThe addition of picogram quantities of bacterial products to rat thymic cells in culture produced a doubling of the proliferative response to suboptimal levels of Concanavalin‐A (Con‐A). This effect was prevented by the depletion of adherent cells which comprised < 0·1% of the total population. The response was restored by the addition of supernatants from peritoneal macrophages which had been stimulated 2 h previously with lipopolysaccharide. Treatment of these supernatants with phenylglyoxal, an inhibitor of interleukin‐1 (IL‐1), did not prevent the stimulatory effect. Augmentation of the thymocyte proliferative response could also be achieved by the addition of a partially purified monokine of relative molecular weight (Mr) 36 000 which is biochemically and functionally distinct from IL‐1 and by a monoclonal antibody which binds to a common determinant on the Ia molecule. Fractionation of the thymic cells on a density gradient yielded a buoyant population which accounted for the majority of the proliferative activity and a dense fraction which was poorly responsive to the mitogen. The addition of the monokine to this latter fraction produced a significant increase in proliferation in response to Con‐A. It is proposed that in the thymus, bacterial products stimulate thymic macrophages to release the Mr 36 000 monokine which in turn stimulates the thymic epithelial cells to release products which promote the survival and maturation of immature thymocytes. This work has implications for the regulation of thymocyte maturation.
Type‐specific monoclonal antibodies produced to proteins of Murray Valley encephalitis virus
Authors: Hall Roy A , Burgess Graham W , Kay Brian H 
Published: July 2007

SummaryTwo monoclonal antibodies have been produced to the flavivirus, Murray Valley encephalitis (MVE). Immunofluorescent antibody and ELISA tests revealed that one antibody was specific for MVE while the other cross‐reacted weakly with Alfuy and Kunjin viruses. These antibodies have neither haemagglutination inhibition nor neutralising activity. One of the monoclonal antibodies reacted with the envelope glycoprotein (E) and a 45,000 MW protein, while the other reacted with a protein of 23,000 daltons. Competitive binding assays confirmed that these antibodies reacted with unrelated epitopes.
Tolerance to aggregated human IgG but not ovalbumin can be induced by concurrent administration of depleting or non‐depleting anti‐L3T4 monoclonal antibodies
Authors: Charlton Brett , Mandel Thomas E 
Published: July 2007

SummaryTolerance to soluble antigens has previously been shown to occur in mice if anti‐L3T4 monoclonal antibody (MoAb) is administered al the time of antigen exposure. The process of tolerance induction may require the depletion of L3T4+ cells or it may be due to down‐regulation or negative signaling of L3T4+ cells. We compared the effects of L3T4+ cell depletion and L3T4 antigen blockade at the time of primary antigen challenge on long‐term humoral responses. Anti‐L3T4 MoAb GK1·5 (IgG2b) and H129·19 (IgG2a) were used to deplete or block, respectively. L3T4+ cells.Following a short course of MoAb and antigen challenge with both aggregated human IgG (ag‐HGG) and ovalbumin (OVA) in each mouse, primary response titres to each antigen in both MoAb treated groups were ∼1:102 compared with ∼1:105 in control mice. Repeated antigen challenge significantly increased the anti‐OVA titre in both MoAb treated groups and by 150 days they were similar to controls. However, anti‐HGG titres did not increase significantly in either of the MoAb treated groups.Thus either depletion of peripheral L3T4+ cells, or blockade of the L3T4 antigen without depletion of peripheral L3T4+ cells, can invoke a state of long‐term antigen‐specific tolerance to some antigens. Why the effect is restricted to particular antigens, and the exact mechanisms of tolerance induction remain to be determined.
Excretory‐secretory antigens from adult Nematospiroides dubius
Authors: Monroy FG , Adams JH , East IJ , Dobson C 
Published: July 2007

SummaryAdult Nematospiroides dubius excretory‐secretory (ES) products were collected from worms cultured in vitro, radiolabelled and separated by sodium dodecyl polyacrylamide gel electrophoresis (SDS‐PAGE). The components were characterized and assessed for molecular weight (MW) after autoradiography and gel staining, for antigenicity in immunoblots, for sensitivity to protease enzymes, and for carbohydrate content. ES contained at least 18 denatured components from MW <20 000 to >200 000. At least one of the surface proteins of adults was found with the ES antigens recovered when adults were cultured in vitro. Molecules with MW 200 000, 78 000 and 60 000 were glycoproteins and reacted with immune mouse serum in Western blots. The dominant ES, MW 60 000 component stained with periodic acid‐Schiff (PAS), bound lectins with affinity for D‐mannose, and was resistant to peptic and tryptic but not V8 protease digestion.
Eicosanoids produced during interactions between Pseudomonas aeruginosa and alveolar macrophages are species‐dependent
Authors: Sorrell TC , Rochester CP , Breen FN , Müller M 
Published: July 2007

SummaryEicosanoid production during phagocytosis of pyogenic bacteria by rabbit alveolar macrophages was studied as a model of early events in the pathogenesis of pneumonia. Adherent alveolar macrophages. prelabelled with [3HJ]‐arachidonic acid (AA), were incubated with live, opsonized Staphylococcus aureus or Pseudomonas aeruginosa (bacteria: macrophage ratio of 50:1) at 37°C for 90 min. Supernatant eicosanoids were extracted and separated by reverse phase high performance liquid chromatography (RP‐HPLC). While the amounts of labelled PGF2, TXB2, and PGD2 produced in response to the two organisms were equal, the amount of PGF2α elicited by S. aureus amounted to three times that released during macrophage challenge with P. aeruginosa. Overall, preferential release of cyclooxygenase products occurred during phagocytosis of S. aureus. In contrast, eicosanoids identified presumptively as oxygenated metabolites of AA predominated in cultures challenged with opsonized P. aeruginosa. Live, non‐opsonized P. aeruginosa elicited the same profile of eicosanoids, but in reduced amounts.Inhibitor studies indicated that these AA derivatives were not synthesized via the macrophage lipoxygenase pathway. Their production was dependent on the viability of P. aeruginosa. Macrophages challenged with opsonized, heat‐killed P. aeruginosa resulted in production of an eicosanoid profile similar to that elicited by S. aureus.Secondary metabolism by P. aeruginosa of eicosanoids released from the macrophage did not contribute to the unique profile produced during the interaction of this organism with labeled macrophages.Our data indicate that during binding to macrophages, the primary human pathogen, P. aeruginosa, specifically modulates the profile of eicosanoids produced. This effect on inflammatory mediators may be of biological significance in the pathogenesis of pneumonia.
Circulating human T and B lymphocytes express the p55 interleukin‐2 receptor molecule (TAC, CD25)
Authors: Zola H , Mantzioris BX , Webster J , Kette FE 
Published: July 2007

SummaryUsing a highly sensitive immunofluorescence procedure 15‐45% of blood lymphocytes from normal human donors can be shown lo react with anti‐TAC (CD25) monoclonal antibodies. The standard procedure for indirect immunofluorescencc docs not allow the detection of these CD25‐positive cells. Ten healthy adults were tested, and all showed a population of positive cells. Three donors have been tested more than once, and have given consistent results. Three different CD25 antibodies were used, again with consistent results. Double‐marker studies showed that the positive cells included B cells, as well as CD4‐bearing and CD8‐bearing T cells.
The murine cellular immune response to adenovirus type 5
Authors: Müllbacher A , Bellelt AJD , Hla RT 
Published: July 2007

SummaryWe have characterized the cellular immune response to human adenovirus 5 (Ad‐5) in mice, as a basis for future study of responses to foreign antigens in recombinant adenoviruses. Primary in vivo lytic effector cells contained both virus immune cytolytic T (Tc) cells and natural killer cells. The Tc effectors could be boosted in vitro to give a secondary Tc cell response. The Tc cell response to Ad‐5 was major histocompatibility complex (MHC) restricted, and in CBA/H (H‐2k) mice mapped to the K end of MHC. Kinetic experiments suggested the Tc cell response was directed against early rather than late viral proteins. Experiments with viral mutants showed that the main responses were to the E1A and E1B proteins, with some involvement of E2. Expression of E3 and E4 in infected targets was not required, in fact lysis of target cells infected by viruses with a deletion in E3 was augmented.
Effect of donor specific transfusion (DST) is restricted to the rat combination used and closely related with alloantibody in heart transplantation
Authors: Hamano K , Ohmi M , Esato K , Fukumoto T 
Published: July 2007

SummaryThe effect of donor specific transfusion (DST) in several donor‐recipient combinations was examined using the rat heart transplantation model. In some donor‐recipient combinations such as LEW to DA, LEW to ACI, LEW to PVG and PVG to DA, DST pretreatment could induce permanent graft survival (>100 days). But in DA to LEW, ACI to LEW, LEW to BN, BN to LEW, PVG to LEW and BN to DA combinations DST pretreatment had no effect on graft survival. The effect of pre‐immunization with several DA antigens (heart, liver, lymph node cells and red blood cells) was examined using the DA to LEW combination in which DST pretreatment was not effective. In no case was permanent graft survival obtained. Alloantibody levels (anti‐class I and anti‐class I + II, respectively) were analysed at the time of heart transplantation and in the post‐transplantation period. The anti‐class I antibody levels were low or not detected in rats with surviving grafts, but in the rats which failed to have the prolonged graft survival, anti‐class I antibody levels were high. This study showed that the effect of DST was restricted to particular donor‐recipient rat combination in the heart transplantation model.
Enhancement of u.v.‐induced skin carcinogenesis in the hairless mouse by inoculation with cell‐free extracts of skin tumours
Authors: Reeve VE , Greenoak GE , Canfield PJ , Boehm‐Wilcox C , Tilbrook PA , Kulski JK , Gallagher CH 
Published: July 2007

SummaryThe presence of papillomaviral‐like DNA has been described in ultraviolet light‐induced tumours in the skin of the hairless mouse (14). Here we describe the effects of the inoculation of cell‐free extracts of ultraviolet light‐induced tumours into the scarified skin of normal hairless mice, prior to exposure of the mice to a cumulative carcinogenic dose of ultraviolet light. Extracts from papillomas or squamous cell carcinomas enhanced the susceptibility of the inoculated mice to ultraviolet light‐induced tumorigenesis, if the extracts contained papillomaviral DNA sequences detected by cross‐hybridization with Mastomys natalensis papillomaviral DNA. The recipient mice developed a greater tumour incidence, tumour yield, tumour diameter and degree of malignancy.
T lymphocytes in infectious mononucleosis; Effect of IL‐2 on the outgrowth of Epstein‐Barr virus‐infected cells
Authors: Misko IS , Burrows SR , Schmidt C , Bishop CJ , Ryan JM , Staples JA , Moss DJ 
Published: July 2007

SummaryThe addition of interleukin‐2 (IL‐2) to lymphocyte cultures from acute infectious mononucleosis (IM) donors dramatically increased the incidence of regression in such cultures and resulted in the emergence of an IL‐2 dependent, CD3 Epstein‐Barr virus nuclear antigen (EBNA)‐negative cell population. Corresponding cultures seeded in the absence of IL‐2 rarely regressed and were quickly dominated by IL‐2 independent, CD3‐negative, EBNA‐positive cells. Lymphocyte cultures from Epstein‐Barr virus (EBV) seropositive donors showed enhanced regression in the presence of IL‐2 but failed to regress after the removal of the E‐rosetting population. Cultures from EBV‐seronegative donors showed no evidence of regression in the presence or absence of IL‐2. E‐rosetting cells isolated from cultures from acute IM donors that had been cultured in the presence of IL‐2 lysed autologous and allogeneic lymphoblastoid cell lines.
The p24 leucocyte membrane antigen: Modulation associated with lymphocyte activation and differentiation
Authors: Zola H , Furness V , Barclay S , Zowtyj H , Smith M , Melo JV , Neoh SH , Bradley J 
Published: July 2007

SummaryMonoclonal antibodies of the CD9 cluster recognize a 24 kD protein (p24) found on platelets and endothelium, and expressed by lymphocytes at restricted stages of maturation and activation. In this study, we explore the possibility that p24 is involved in the response of lymphocytes to signals delivered by lymphokines. p24 is expressed only very weakly by resting B lymphocytes. We found no increase in expression when cells were activated with anti‐immunoglobulin together with interleukin‐4, or induced to proliferate by low‐molecular weight B cell growth factor (LMW‐BCGF). Culture of activated B cells with B cell differentiation factor was associated with an increased mean expression of p24. In cells from a patient with chronic lymphocytie leukaemia (CLL), culture with LMW‐BCGF up‐regulated p24 expression. Resting T cells (p24‐negative) were induced to express p24 strongly when activated with antibody against CD3. CD9 antibody did not modulate B or T cell responses to activation stimuli. The results suggest that the p24 molecule is not involved in the primary interaction of cells with lymphokine, but rather may be involved in a secondary reaction, such as ion flux, which follows as a consequence of the action of lymphokines on cells.