bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human cytomegalovirus‐specific cytotoxic T lymphocytes: requirements for in vitro generation and specificity
Authors: Borysiewicz Leszek K. , Morris Susanna , Page Jamie D. , Patrick Sissons J. G. 
Published: February 2007

AbstractThe nature of any virus‐specific T cells involved in controlling human cytomegalovirus (HCMV) infection in normal subjects harboring latent virus is unknown. As an approach to this problem, peripheral blood mononuclear cells (PBM) from normal seropositive subjects were cocultured with HCMV and responding T cells expanded in interleukin 2 (IL2)‐dependent culture, determining in particular whether HCMV‐specific cytotoxic T cells (Tc) were generated. Coculture of PBM with free HCMV resulted in the generation of short‐term T cell lines of predominantly helper phenotype (Leu 3a+), expressing no cytotoxicity. However, when PBM were cocultured on HCMV‐infected fibroblasts (autologous to the donor in these experiments) predominantly Leu 2a+ lines were generated, which lysed HCMV‐infected cells. The cytotoxicity of these short‐term IL2‐dependent lines was HCMV‐specific and human HLA‐restricted; HCMV‐infected target cells expressing only early viral antigens were lysed. It is concluded that HCMV‐specific Tc precursors are present in peripheral blood of latently infected individuals without preceding overt infection and that effector Tc may be capable of lysing infected cells prior to viral replication.
Standard sera in solid‐phase immunoassays
Authors: Mäkelä Olli , Péterfy Ferenc 
Published: February 2007

AbstractSolid‐phase immunoassay‐derived antibody titers are often converted to weight unit concentrations with the aid of standard sera containing known antibody concentrations. Systematic studies justifying this procedure have not yet been published. We therefore investigated the magnitude of errors associated with this conversion. Antibody concentrations of thirteen sera or ascites fluids were determined by quantitative precipitation or equlibrium dialysis, and one was then used as a “standard antibody” for the others in solid‐phase radioimmunoassay (SP‐RIA) or enzyme‐linked immunosorbent (ELISA) assays.Antibody concentrations determined by the conventional solid‐phase assay (the “standard serum” has the same specificity as the “sample”) had up to fourfold errors. These errors could be reduced by basing the conversion on the combination of two standard sera instead of one.The possibility was studied of whether the conversion to weight units could be done with the aid of a standard serum directed to a different antigen than the sample antibody. Errors associated with the use of such a heterologous standard were not significantly greater than those found using the conventional conversion. A combination of two reference sera again reduced the errors. The use of such heterologous standard(s), however, requires checking the binding capacity of the antigen coats.
One out of five peripheral blood B lymphocytes is activated to high‐rate Ig production by human alloreactive T cell clones
Authors: Lanzavecchia Antonio 
Published: February 2007

AbstractHuman alloreactive helper T cell clones were isolated from a secondary mixed lymphocyte reaction by limiting dilution in the presence of irradiated stimulator cells and T cell growth factor (interleukin 2). When cultured with B cells and macrophages possessing the relevant alloantigens, the T cell clones proliferated and induced a strong B cell activation with production of high immunoglobulin levels. Limiting dilution of the B cells from the peripheral blood showed that about one in 5–10 can be activated to produce IgG, one in 10 IgM, one in 20–40 IgA and one in 2000–5000 IgE. Following stimulation by the relevant alloantigen, the clones were able to help also B cells that lacked the alloantigen, indicating that a direct T‐B cell interaction is not required.This method is particularly interesting because it is suitable for the clonal analysis of a B cell subset that is triggered in the absence of antigen by an unrestricted T cell help.
Molecular nature of the W3/25 and MRC OX‐8 marker antigens for rat T lymphocytes: comparisons with mouse and human antigens
Authors: Thomas Matthew L. , Green Jon R. 
Published: February 2007

AbstractThe mouse monoclonal antibodies W3/25 and MRC OX‐8 have been used to distinguish rat T lymphocyte subpopulations. In the peripheral T lymphocyte population, W3/25 antibody recognizes an antigen on the Thelper (Th) subset, while MRC OX‐8 antibody recognizes an antigen on the Tsuppressor/cytotoxic (Ts/c) subset. To determine the nature of these antigens, rat thymocytes were either metabolically labeled with [35S]L‐methionine or surface‐labeled at sialic acid residues by periodate oxidation followed by [3H]NaBH4 reduction. Thymocytes were solubilized with nonionic detergent, the antigens immunoprecipitated and the molecular weights determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis. Using metabolically labeled cells, W3/25 antibody immunoprecipitated an antigen that electrophoresed under reducing conditions as a broad band between 48000–53000 Mr. Unreduced samples migrated between 46000–50000 Mr. Surface‐labeled W3/25 antigen, electrophoresed under reducing conditions, separated into two bands of 44000 and 52000 Mr. Metabolically labeled MRC OX‐8 antigen was identified as a protein of at least two chains of 39000 and 34000 Mr. There was also a fainter band at approximately 67000 Mr. Unreduced samples indicated a more complex structure with bands at 70000, 110000 and 165000 Mr. Surface‐labeled MRC OX‐8 antigen was of similar nature. These data, when considered with functional and tissue distribution data, suggest that W3/25 antigen is equivalent to T4 in man and MRC OX‐8 antigen is equivalent to T8 in man, and Lyt‐2 in mouse.
The specificity of H‐2‐restricted cytotoxic T lymphocytes directed to AKR/Gross leukemia virus‐induced tumors II. Altered gp70 display and production of noninfectious virus particles by an insusceptible variant tumor
Authors: Green William R. , Brown Melissa A. 
Published: February 2007

AbstractDerived from the susceptible AKR.H‐2bSL1 tumor cell line, a variant tumor subclone, cl.18‐5, was selectively insusceptible to H‐2‐restricted anti‐AKR/Gross virus cytotoxic T lymphocytes (CTL) due to its failure to be recognized. In this study, the expression of virus‐related products by variant cl.18‐5 cells was compared to that of AKR.H‐2bSL1 cells and a susceptible clone, as an approach towards defining the virus‐associated antigens recognized by anti‐AKR/Gross virus CTL.Despite the type specificity of the CTL, cl.18‐5 displayed normal levels of the group‐specific antigen (gag) encoded proteins p30, p15, p12 and p10, and the gag‐associated Gross cell surface antigen. These results were confirmed by fluorescence‐activated cell sorter analysis employing monoclonal antibodies specific for either AKR p12 or the cell surface glycosylated form of AKR ecotropic gag product. In contrast, cl.18‐5 was variably less sensitive than AKR.H‐2bSL1 to the action of complement and xenogeneic antisera directed against the envelope (env) product gp70. In addition, a panel of five monoclonal antibodies to gp70, which detect distinct endogenous ecotropic viral determinants, lysed AKR.H‐2bSL1, but not cl.18‐5 cells. However, absorption experiments indicated that cl.18‐5 did express near normal levels of these specificities, suggesting an alteration in the orientation or topographical distribution of these determinants.Consistent with an inappropriate display of env products, cl.18‐5 was found to be deficient in the production of infectious ecotropic leukemia virus. The particulate fraction of the cell‐free supernatant of cl.18‐5 contained normal levels of reverse transcriptase activity, indicating that noninfectious viral particles were being produced. Collectively, these results point to an association between recognition by anti‐AKR/Gross virus CTL and the expression of ecotropic gp70 required for infectivity of virus.
Allocytotoxic T cell clones: both Leu 2+3− and Leu 2−3+ T cells recognize class I histocompatibility antigens
Authors: Flomenberg Neal , Naito Kazuyuki , Duffy Ellen , Knowles Robert W. , Evans Robert L. , Dupont Bo 
Published: February 2007

AbstractT cell clones were selected which were cytotoxic for human class I major histocompatibility target antigens. Specificity was based on target cell panel studies and inhibition by monoclonal antibodies to class I determinants. Eight clones were Leu 2+3−. The cytotoxicity of these clones was inhibited by antibody to the Leu 2 antigen. Two clones expressed the Leu 2−3+ phenotype and were not inhibited by anti‐Leu 2a or anti‐Leu 3a antibodies. These studies indicate that class I‐specific cytotoxic T cells are distributed in both T cell subsets, though predominantly in the Leu 2+3− group. In addition, these studies suggest that the Leu 3 molecule may not function in identical fashion in Leu 3+ cytotoxic T cells, which recognize class I target antigens, as in those which recognize class II targets.
Selection and continuous growth of antigen‐specific human T cells by antigen‐treated monocytes
Authors: Barak Vivian , Fuks Zvi , Galilli Naomi , Treves Abraham J. 
Published: February 2007

AbstractAntigen‐specific human T lymphocytes were selected by adsorption of peripheral blood mononuclear cells on monolayers of antigen‐treated autologous monocytes. The enriched cell populations were propagated in interleukin 2‐containing medium for 60–80 days. Their activity was tested by a proliferative response against the sensitizing antigen in the presence of irradiated autologous lymphocytes. Continuous cultures of enriched T cells responded specifically to three different protein antigens. The specific reactivity induced in vitro against at least one of the antigens was probably a primary response. In addition, the selected cultures were found to be enriched for OKT4‐positive cells, in contrast to cultures of nonselected T cells which were enriched for OKT8‐positive cells. These properties of the selected T lymphocyte populations were obtained following only one exposure to the sensitizing antigen, which was concomitant with adsorbance on monocytes and without cloning of the reactive cells. We suggest that specific adsorbance of lymphocytes on antigen‐treated monocytes may result in a T cell population which combines both properties of antigen specificity and enrichment for the helper proliferative subset of T cells.
Activation of human T lymphocytes I. Requirements for mitogen‐induced proliferation of antigen‐specific T lymphocyte clones
Authors: Fleischer Bernhard 
Published: February 2007

AbstractIn a model system for accessory cell (AC)‐dependent mitogen‐induced T cell proliferation the response of several human antigen‐specific, HLA‐restricted helper T lymphocyte clones (HTLC) to mitogens was studied. It was found that the HTLC themselves did not or only weakly respond to various mitogens or to oxidation by galactose oxidase, but that the response could be strongly increased if certain tumor cell lines were added to the assay as AC. Pretreatment with lectins or oxidation of either HTLC or AC was effective in stimulating the proliferation of the T cells in this system. Reduction of the aldehydes formed during oxidation completely abolished the stimulatory activity of oxidized B lymphoblastoid cell line. This shows that crosslinking of T cell and AC is required to induce proliferation.When several established cell lines were tested for their capacity to function as AC in this system, profound differences in AC activity were detected. The inability of cells with poor AC activity to stimulate the HTLC was not due to trivial reasons, such as requirements for different mitogen concentrations, a decreased binding of mitogens or suppressive effects. Furthermore, AC activity was not dependent on the presence of Ia antigens on the AC. These findings are discussed with regard to the mechanism of mitogen‐induced T cell activation.
Chromosome assignment of monoclonal antibody‐defined determinants on human leukemic cells
Authors: Katz Fay , Povey Susan , Parkar Mohamed , Schneider Claudio , Sutherland Robert , Stanley Karina , Solomon Ellen , Greaves Melvyn 
Published: February 2007

AbstractHybrids formed between human acute lymphoblastic leukemia (ALL) cells and mouse myeloma have been used to determine the chromosomal location of genes required for the expression of several monoclonal antibody (mAb)‐defined cell surface antigens on ALL cells. Cloned hybrids were tested for antibody binding, immunoprecipitation of the relevant protein, chromosome isoenzyme markers and karyotype. Two antigens of those studied could be definitively mapped, OKT10/p45 to chromosome 4 and BA‐2/p24 to chromosome 12. mAb BA‐2 reacts with the same protein as another mAb designated 609‐29 (anti‐teratocarcinoma). Reactivity with the latter mAb has been previously shown to segregate with chromosome 12.
Fine specificity of the immune response to oxazolones III. Antibodies but not contact sensitivity specific for 2‐furyloxazolone are controlled by an Igh‐V gene in the mouse
Authors: Mäkelä Olli , Matoso‐Ferreira Antonio , Kaartinen Matti 
Published: February 2007

AbstractEarly IgM and IgG antibodies of CBA and C3H mice (Igh allotype j) against furyloxazolone (furyl Ox) were found to be heteroclitic, they had a 4–6 times higher affinity for styryloxazolone (styryl Ox) than for furyloxazolone. Anti‐furyl Ox antibodies of six other strains (Igh allotypes a, b, c, e, f or g) had approximately 100 times higher affinity for furyl Ox than for styryl Ox. The heteroclitic fine‐specificity was inherited as an Igh allotype‐linked trait.Furyl Ox‐specific contact sensitivity was induced by painting, and its specificity was studied with a recently developed method (Ferreira et al., J. Immunol. 1981. 127: 2366). Small strain differences in specificity were detected. They were not inherited as an Igh allotype‐linked trait.
Marginal zone B cells express CR1 and CR2 receptors
Authors: Gray David , McConnell Ian , Kumararatne Dinakantha S. , Maclennan Ian C. M. , Humphrey John H. , Bazin Hervé 
Published: February 2007

AbstractOpsonized yeast is known to bind strongly to the marginal zones in frozen sections of rat spleen (Kumararatne, D. S. et al., Eur. J. Immunol. 1981. 11: 858). This study reports an analysis of the cells involved in this binding. Sheep red cells coated respectively with C3b, C3bi or C3d were used as indicator cells. These showed homogeneous binding of both C3b and C3bi to marginal zones and germinal centers. C3d‐coated red cells bound in a uniform speckled pattern to marginal zones. They also bound to germinal centers and the small lymphocyte zones of the follicles. Selective depletion experiments were undertaken to show that binding to marginal zones was a property of the IgM+ and IgD− B cells characteristic of this area. Binding to germinal centers was attributable to follicular dendritic cells. The C3d receptors in follicles were shown to be on IgM+ and IgD+ small B lymphocytes.
Monoclonal autoantibodies to histones from autoimmune NZB/NZW F1 mice
Authors: Laskov Reuven , Muller Sylviane , Hochberg Malka , Giloh Haim , van Regenmortel Marc H. V. , Eilat Dan 
Published: February 2007

AbstractFusion of spleen cells from autoimmune NZB/NZW female mice with drug‐resistant myeloma cells (clones NSI/1, X63‐Ag8.653 and NSO/1) produced hybrid clones which secreted antibodies to various nuclear components. Roughly 50% of the anti‐nuclear hybridomas produced antibodies reacting with DNA, 20% with RNA and 30% reacted with other nuclear antigens. Two hybridomas of the latter group were cloned and studied in detail. They secreted antibodies which produced bright fluorescence staining of nuclei and metaphase chromosomes. The specificity of the antibodies was determined by testing them in an enzyme‐linked immunosorbent assay and a radioimmunoassay against individual acid‐ and salt‐extracted histones, against histones mixed two and three at a time and against histone complexes isolated as such from chromatin. One of the monoclonal antibodies was specific for histone H2B and reacted with the histone free in solution or when present as a H2A‐H2B complex. The second monoclonal antibody recognized a specific conformation in the H3‐H4 complex that was present only when the complex was obtained from chromatin by salt extraction. The same conformation, however, could be induced by adding histone H2B to a mixture of acid‐extracted H3 and H4.Our findings show that the autoimmune syndrome in NZB/NZW mice resembles human systemic lupus erythematosus not only in the incidence of antibodies to DNA and RNA, but also in the production of autoantibodies to histones.
The expressed lysozyme‐specific B cell repertoire I. Heterogeneity in the monoclonal anti‐hen egg white lysozyme specificity repertoire, and its difference from the in situ repertoire
Authors: Metzger Dennis W. , Ch'ng Lean‐Kuan , Miller Alexander , Sercarz Eli E. 
Published: February 2007

AbstractA panel of closely and distantly related lysozymes and lysozyme‐peptide fragments were utilized in assessing the specificity repertoire of murine anti‐hen egg white lysozyme hybridomas. The 44 monoclonal antibodies could be divided into a minimum of 18 fine specificity groups in tests using the lysozyme panel. Two hybridoma products were specific for epitopes containing amino acids 68 and 121, respectively; and another was specific for an epitope including amino acids 113–114. Several hybridomas demonstrated unique heteroclitic binding, for example, to bob‐white lysozyme (BEL), but not other closely related lysozymes, suggesting lysine at position 68 in BEL as an important residue of recognition. Radioimmunoassays using lysozyme peptides bound to plastic plates specified the regional specificity of 6 additional antibodies of the 44. A comparison of the specificities of monoclonal antibodies with antibody produced in vivo showed some major differences suggesting that those cells proceeding on to antibody formation in the regulatory milieu of the whole animal are a selected subpopulation.
Activation and proliferation signals in mouse B cells I. A comparison of the capacity of anti‐Ig antibodies or phorbol myristic acetate to activate B cells from CBA/N or normal mice into G1
Authors: Hawrylowicz Catherine M. , Keeler Keith D. , Klaus Gerry G. B. 
Published: February 2007

AbstractB lymphocytes from the CBA/N mouse do not synthesize DNA when cultured with anti‐Ig antibodies. However, these cells like normal B cells, do manifest increased Ia antigen expression and RNA synthesis (i.e. enter G1) when stimulated by anti‐Ig, even at doses which are nonmitogenic for normal B cells. Pretreatment of both normal and CBA/N B cells with anti‐Ig also primes them to give an enhanced proliferative reponse to lipopolysaccharide (LPS). The tumor promoter phorbol myristic acetate (PMA) also enhances RNA synthesis and Ia antigen expression in B cells from both normal and CBA/N mice. However, PMA only primes CBA/N B cells to respond to LPS: pretreatment of normal B cells with PMA causes a modest suppression of LPS‐induced, and a marked suppression of anti‐Ig induced, DNA synthesis.These results therefore confirm and extend earlier data showing that there are distinct activating (G0 to G1) vs. proliferative (G1 to S) signals discernible in B cells. They also suggest that the activation mechanism of CBA/N B cells is subtly different from that of any known subpopulation of normal B cells.
Mechanism of activation of the classical pathway of complement by monoclonal IgE (DES). Restricted regulation of C4b by C4b‐binding protein
Authors: Saint‐Remy Jean‐Marie R. 
Published: February 2007

AbstractA human monoclonal IgE from patient DES, IgE (DES), has been shown to activate the classical pathway of complement. The mechanism of this activation has been investigated and can be summarized as follows: (a) IgE (DES) is able to bind and activate C1 in a dose‐dependent fashion. This activation increases with the size of the aggregates used, but the affinity of C1 for IgE (DES) is weaker than for IgG. (b) A classical pathway C3 convertase can be assembled on IgE (DES) using purified C1, C4 and C2. The formation decay of this convertase is similar to that formed on IgG with an half‐life of 9 min at 37 °C. (c) The extrinsic regulation of the C3 convertase by C4bp is restricted on IgE (DES) as compared to IgG. This restriction is shown on both the formation and the decay of the convertase. The mechanism of activation of the classical pathway of complement by IgE (DES) thus present some similarities with the assembly of the C3 convertase by the alternative pathway.
Isolation of follicular dendritic cells from human tonsils and adenoids. II. Immunocytochemical characterization
Authors: Heinen Ernst , Lilet‐Leclercq Chantal , Mason David Y. , Stein Harald , Boniver Jacques , Radoux Daniel , Kinet‐Denoël Cécile , Simar Léon J. 
Published: February 2007

AbstractFollicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the generation of B cell memory. In the present report the isolation of FDC from human tonsils and adenoids is described. These isolated cells have an unusual spherical arrangement and enclose lymphocytes within extensions of their membranes. Their ultrastructural features are similar to those observed in situ. The reactivity of isolated FDC with a number of monoclonal antibodies was analyzed by immunofluorescence and by immunostaining (at the electron microscopic level) with colloidal gold. In keeping with the results of previous investigations on tissue sections IgM, IgG and IgA (but not IgD) can be detected on the surface of isolated FDC, as can C3b receptors and the FDC‐associated antigen detected by monoclonal antibody R4/23. The immunoglobulins associated with FDC are mostly embedded in an electron‐dense material. The majority of the lymphoid cells enclosed within the membrane extensions of FDC are of B cell type. These results suggest that isolated FDC may be suitable for further in vitro investigation of their role in the humoral immune response.
Cyclosporin A inhibits the delayed‐type hypersensitivity reaction: impaired production of early pro‐inflammatory mediator(s)
Authors: Shidani Babak , Milon Genevieve , Marchal Gilles , Truffa‐Bachi Paolo 
Published: February 2007

AbstractThe effect of cyclosporin A (CsA) on the delayed‐type hypersensitivity (DTH) elicited in mice by sheep red blood cells was investigated. Evidence is presented that a single injection of CsA adversely affects the inflammatory reaction. Sensitized T lymphocytes initiate the DTH reaction by their recruiting activity on phagocytic cells which infiltrate the cutaneous site of antigen deposition. CsA administration has no adverse effect on the recruitment of phagocytic cells at the site of the inflammatory reaction. The present studies show that CsA acts on specific T cells: (a) in adoptive transfer, T‐DTH‐mediating cells cannot elicit a response in mice treated with CsA 8 h before; (b) when collected 8 h after a single injection of CsA, T‐DTH‐mediating lymphocytes are no longer able to adoptively transfer the reaction. This conclusion is strengthened by in vitro studies: (a) the frequency of T‐DTH‐mediating lymphocytes is 50‐fold decreased after a short in vitro incubation with CsA; (b) in vitro production by concanavalin A‐activated lymphocytes of chemotactic pro‐inflammatory mediator(s) is abolished in presence of CsA.