bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wheat germ agglutinin activates macrophages for collaboration with B cells
Authors: Bernabe Rosa R. , Martinez‐Alonso Carlos , Larsson Eva‐Lotta , Coutinho Antonio 
Published: February 2007

AbstractWheat germ agglutinin (WGA), added to Mishell‐Dutton‐type cultures of nude spleen cells challenged with erythrocyte antigens, allows a primary specific plaque‐ forming cell (PFC) response. WGA, however, does not display direct mitogenicity to either T or B lymphocytes. The activity of WGA in the specific PFC response is macrophage‐dependent and parallels a nonspecific PFC response in the same cultures.
Cytotoxic T cell responses to haptenated cells I. Primary, secondary and long‐term cultures
Authors: Pohlit Helmut , Haas Werner , von Boehmer Harald 
Published: February 2007

AbstractCytotoxic T lymphocyte (CTL) responses were obtained in vitro to cells coupled with several different haptens. The degree of lysis of target cells was dependent on the amount of hapten coupled to stimulator and target cells. Spleen cells from normal mice responded to high‐hapten density cells but not to low‐hapten density cells. However, spleen cells from immunized CBA mice could be stimulated in vitro by low‐ hapten density cells to generate effector cells able to lyse low‐hapten density cells. In vitro primed responder cells could be restimulated in the presence of the original hapten‐coupled stimulator cells or in the presence of supernatant from concanavalin A‐stimulated mouse or rat spleen cells. Large numbers of hapten‐specific and H‐2‐ restricted CTL could be generated by repeated exposure to fresh supernatant.
The in vitro cellular response of human lymphocytes totrinitrophenylated autologous cells: HLA‐D restrictionof proliferation but apparent absence of HLArestriction of cytolysis
Authors: Charmot Dominique , Mawas Claude 
Published: February 2007

AbstractPrimary as well as secondary proliferative and cytotoxic responses to 2,4,6‐trinitrophenyl (TNP)‐modified autologous human cells have been studied. Proliferativeresponses have been obtained both by primary (peak on day 6) and secondary (peakon day 2–3) stimulation. Both responders and nonresponders were found among thepanel of unrelated individuals tested. All responders in a secondary reaction also gavesignificant primary responses. Intrafamilial studies showed that the ability to restimulate a proliferative response followed the major histocompatibility complex haplotypeof the responder; in some cases, the two haplotypes differed in their ability to restimulate.Using unrelated individuals typed for HLA‐A, B and C, as well as HLA‐D and DR, proliferation was shown to occur only when the unrelated stimulator shared HLA‐Dregion products with the responder.In contrast, no HLA restriction was found in cell‐mediated lympholysis (CML)(neither in primary nor in secondary responses) in most cases. The data suggest thatthe observed killing is independent of sensitization. Both responders and nonresponders in proliferation yielded high levels of lysis; no increase of lysis was found in kineticstudies; most allogeneic CML combinations were highly lytic for the TNP‐modifiedresponder cells at a time when the lysis of the specific allogeneic target is negligible. These preliminary data suggest that the killing observed might be different fromclassical T cell‐mediated lympholysis.
Education of mouse lymphocytes against human lymphoblastoid cell lines: Specific recognition of determinants independent of serologically defined HLA allotypes and Epstein‐Barr virus‐coded antigens
Authors: Carnaud Claude , Errasti Pedro , van der Gaag Ruth 
Published: February 2007

AbstractIn this report, a model of xenogeneic education is described, whereby cytotoxic mouse spleen cells are generated against human target cell antigens. To generate a significant response, a primary in vivo immunization followed by an in vitro boosting 4 to 8 weeks later is required.Lysis is totally abrogated after treatment of the effector cells by anti‐Thy‐1.2 antiserum plus complement confirming the T origin of these effectors. Such cytotoxic T lymphocytes (CTL) do not discriminate between two lymphoblastoid cell lines carrying different HLA‐A and HLA‐B specificities, either by direct assay or by competition assay with unlabeled target cells. Moreover, Daudi cells which lack the serologically defined (SD) HLA antigens, are susceptible to CTL specifically raised against Daudi. However, CTL raised against another B line do not lyse Daudi, and, reciprocally, anti‐Daudi CTL do not lyse other B lines thus suggesting a polymorphic distribution of xenogeneic determinants on human lymphoid lines. A third specificity is revealed when mouse spleen cells are educated against human T lines. The CTL generated under these conditions lyse not only the line used for sensitization but the three other human T lines of the panel. On the other hand, they affect none of the B cell lines (including Daudi) nor phytohemagglutinin or concanavalin A‐induced T blasts. In conclusion, the mouse T cell repertoire is capable of recognizing a polymorphic system of antigens expressed on human lymphoblastoid cell lines that is not related to the expression of HLA‐SD antigens nor to that of the Epstein‐Barr virus genome.
IgG‐binding sites on macrophage cell membrane. I. Identification of two distinct Fc receptors on mouse peritoneal macrophages
Authors: Sulica Andrei , Gherman Maria , Medesan Cornel , Sjöquist John , Gheţie Victor 
Published: February 2007

AbstractEvidence is presented concerning the existence on mouse peritoneal macrophages of two separate and distinct Fc receptors, one for cytophilic monomeric IgG (mIgG) and the other for polymeric IgG. The latter Fc receptor recognizes both heat‐aggregated IgG and antigen‐complexed IgG. The major findings of our studies are: (a) the different susceptibility of the two Fc receptor types by pronase, trypsin or phospholi‐ pase C; (b) the independent modulation of these two binding sites on the cell membrane; (c) the inability of mIgG to inhibit the binding of particulate antigen‐complexed IgG ligand; (d) the ability of mIgG molecules which are devoid of the cytophilic property to attach to the macrophage surface upon their polymerization induced by heating or antigen.The results are discussed in terms of “cytophilic” and “opsonic” Fc receptor types which may provide different functional abilities for normal macrophages.
Generation of effector cells from T cell subsets. II. Lyt 123 T cells contain the precursors for all primary cytotoxic effector cells and for cells involved in the regulation of cytotoxic responses
Authors: Simon Markus M. , Abenhardt Birgit 
Published: February 2007

AbstractMixed responder populations, consisting of selected Lyt‐2,3+ cells and unselected T cells from two congenic mouse strains differing in their Lyt‐2,3 alleles, were used to study the role of Lyt‐1,2,3+ cells in the generation of cytotoxic effector cells in vitro. The fact that, under these conditions, all primary alloreactive and H‐2‐restricted killer cells are generated from the unselected T cell population and not from the selected Lyt‐2,3+ subset is demonstrated. Isolated, unsensitized Lyt‐2,3+ cells are able to produce primary alloreactive cytotoxic T lymphocytes (CTL) when incubated with alloantigen alone, but appear to be suppressed in the presence of Lyt‐1,2,3+ cells. In contrast, mixtures of Lyt‐2,3+ cells selected from C 57 BLI6 T cells previously primed to alloantigen in vitro, and unselected T cells from the Lyt‐2,3‐congenic partner after exposure to the same antigen give rise to cytotoxic effector cells which derive mainly from the primed Lyt‐2,3+ cell pool and not from the unselected T cell population. Both populations were able to generate CTL when sensitized separately with the alloantigen. The data suggest that Lyt‐1,2,3+ cells contain all primary precursors for both H‐2‐restricted and alloreactive killer cells, as well as lymphocytes suppressing the formation of cytotoxic effector cells from unsensitized Lyt‐2,3+ cells. The Lyt‐ 2,3+ cell pool most likely contains the secondary CTL precursors. In addition, the same antigen‐primed Lyt‐2,3+ pool contains suppressor cells which inhibit the formation of primary CTL from Lyt‐1,2,3+ cells. The data are discussed with respect to the regulation of cytotoxic responses.
Expression of blood group I and i active carbohydrate sequences on cultured human and animal cell lines assessed by radioimmunoassays with monoclonal cold agglutinins
Authors: Childs Robert A. , Kapadia Anupsheela , Feizi Ten 
Published: February 2007

AbstractHuman monoclonal anti‐I and anti‐i antibodies, reactive with known carbohydrate sequences, have been used as reagents to quantitate (by radioimmunoassay) and visualize (by immunofluorescence) the expression of the various blood group I and i antigenic determinants in a variety of cultured cell lines commonly used in laboratory investigations. It has been shown that the antigens they recognize are widely distributed on the surface of human and animal cell lines, expressed in varying amounts in different cell lines and on individual cells within a given cell line. In two cell lines, a transformation‐associated increase in the expression of I antigen was observed. Because of their precise specificity for defined carbohydrate chain domains, these autoantibodies have become valuable reagents in biological chemistry.
Epitope specificity of the T cell proliferative response to lysozyme: proliferative T cells react predominantly to different determinants from those recognized by B cells
Authors: Maizels Richard M. , Clarke Jessica A. , Harvey Michael A. , Miller Alexander , Sercarz Eli E. 
Published: February 2007

AbstractThe fine specificity of murine B 10.A/SgSn (B 10.A) T cells reactive with hen egg‐white lysozyme (HEL) has been studied through the use of reduced, carboxymethylated HEL, a set of peptides encompassing the entire molecule, and a set of variant lysozymes from other species. Cells were taken from the lymph nodes draining the site of immunization at the base of the tail, and were restimulated in vitro with immunogen or analogue to measure T cell reactivity.Unlike B cell reactivity, which we have shown to be mainly associated with an epitope preserved in the N‐C peptide (residues 1–17, Cys 6‐Cys 127, 120–129) most T cell reactivity appears to be directed towards a limited number of determinants on cyanogen bromide cleavage fragment II of HEL (LII) (13–105). This was confirmed by a cell‐dilution assay in which antigen‐reactive units are measured; reactivity was highest to LII, intermediate to N‐C, and low but significant to cyanogen bromide cleavage fragment III (LIII) (106–129). Furthermore, priming with LII is as effective as immunization with HEL and results in the same extensive cross‐reactivities to variant lysozymes.Although LII reactivity predominates in the response to HEL, injection of LIII and N‐C reveals sizeable reactivity to the homologous peptides and to HEL. By crossstimulation studies, specific epitopes could be defined in certain regions of HEL. B 10. A is clearly responsive to the overlap between N‐C and LII (residues 13–17), and to an epitope in the region 106–121, but is poorly responsive to the C‐terminal portion (120–129). The response to 106–121 is characterized by an exquisite specificity in which as little as a single amino acid substitution (Asn for Gln) is recognized.
Antigen‐independent binding of IgG dimers to C1 q as studied by sedimentation equilibrium, complement fixation and electron microscopy
Authors: Tschopp Jürg , Villiger Werner , Lustig Ariel , Jaton Jean‐Claude , Engel Jürgen 
Published: February 2007

AbstractRabbit anti‐SII pneumococcal polysaccharide IgG antibody was cross‐linked by dithiobis (succinimidyl propionate). The IgG dimers were visualized by electronmicroscopy and resembled two Y‐shaped structures connected in random orientations. The three arms of the Y's were of equal length. The six globular domains of the IgG protomers could be seen, but the Fab arms and Fc stems could not be distinguished from each other. Electron microscopy revealed that the dimers were bound to the globular heads of C1 q. From the dependence of the weight average molecular weight on dimer concentration, an equilibrium constant of about 106 M−1 was derived for the binding of dimers to C1 q. The number of IgG dimers which could be accommodated at a single C1q molecule was derived to be three. The data do not allow a clear distinction between noncooperative and cooperative binding.The binding equilibrium was independent of whether the IgG dimers were liganded with an SII nonasaccharide hapten or not. The results are at variance with an allosteric mechanism of the action of antigen in C1 activation. They lend support to the association hypothesis of complement activation. The data suggest that clusters of about six IgG molecules, connected by a multivalent antigen or arranged at the cell surface, are recognized by C1 q with a binding constant of about 1010 M−1.
Major histocompatibility complex‐restricted and unrestricted T helper cells recognizing minor histocompatibility antigens of B cell surfaces
Authors: Coutinho António , Augustin Andrei A. 
Published: February 2007

AbstractThe present experiments analyze the functional properties of helper T cells specific for “minor” histocompatibility antigens. T cells from C3H/HeJ mice, primed in vivo and highly enriched in vitro for reactivity to membrane antigens of C3 H/Tif B cells, specifically proliferate, and provide polyclonal help to splenic B cells from strains carrying a variety of different H‐2 haplotypes on C3H or BALE backgrounds, while failing to respond to cells carrying the same H‐2 haplotypes on C 57 BL or A backgrounds. Since it has been previously demonstrated (A. A. Augustin and A. Coutinho, J. Exp. Med. 1980. 151: 587) that B cell activation in this system strictly requires direct, specific recognition of B cell surface antigens by helper cells and does not result from the production of soluble “mitogenic” or “nonspecific helper factors”, it is concluded that this phenomenon represents specific, major histocompatibility complex (MHC)‐unrestricted T cell help. In addition, it has now been found that expression of helper activity requires viability of the helper cells and is partially radiation‐sensitive. Lack of MHC restriction is not a general property of specific helper cells which directly recognize B cell “minor” antigens, since BALB.C3 H anti‐C3 H/Tif T cells appear to be restricted by H‐2 in their polyclonal helper activity. The helper activity mediated by specific anti‐“minor”, H‐2‐restricted helper cells could not be inhibited by anti‐VH antibodies, and the inhibition obtained with anti‐Ia antibodies appeared to operate at the level of B cell induction, rather than at the level of helper cell activation.
Species‐restricted effects of human and mouse lymphokines on macrophages
Authors: Tagliabue Aldo , Mantovani Alberto , Boraschi Diana , Herberman Ronald B. 
Published: February 2007

AbstractLymphokines produced by antigenic or mitogenic stimulation of human, guinea pig and mouse lymphocytes were tested for their effects on monocytes or macrophages of the same and heterologous species, to determine whether there is any species restriction in their reactivity. Supernatants from lymphocyte cultures were tested for migration inhibitory activity in an indirect agarose microdroplet assay and for their ability to augment cytolytic activity of macrophages or monocytes in a [3H] thymidine‐release assay. Supernatants of human peripheral blood mononuclear cells, stimulated with phytohemagglutinin or purified protein derivative of tuberculin (PPD) were able to strongly inhibit the migration of human monocytes and guinea pig peritoneal exudate cells (PEC), but had no detectable effect on mouse PEC. The human Supernatants could also significantly augment the cytolytic activity of human monocytes, but had no effect on cytotoxicity by mouse peritoneal macrophages. Conversely, Supernatants of PPD‐stimulated spleen cells from mice immune to bacillus Calmette‐Guérin (BCG) strongly inhibited the migration of, and significantly augmented cytolysis by, mouse PEC, but had no detectable effects on human monocytes. Moreover, Supernatants of concanavalin A‐stimulated lymph node cells from guinea pigs inhibited the migration of guinea pig PEC and human monocytes, but had no effects on mouse PEC. The migration inhibitory effects of the human and mouse Supernatants did not appear to be mediated by interferon (IF), since partially purified type‐1 IF had no detectable effect. In addition, Supernatants of human lymphocytes stimulated by Corynebacterium parvum strain 5888, that induced little or no IF, were able to inhibit the migration of, and augmented cytolysis by, human monocytes. These C. parvum super‐natants also showed migration inhibitory activity on mouse PEC but did not induce cytolytic activity in these cells'.
Gene complementation in the T lymphocyte proliferative response to poly(Glu56Lys35Phe9)nFunctional evidence for a restriction element coded for by both the I‐A and I‐E subregions
Authors: Schwartz Ronald H. , Chen Chuan , Paul William E. 
Published: February 2007

AbstractThe T lymphocyte proliferative response to poly(Glu56Lys35Phe9)n (GLΦ) is under the control of two immune response genes, Ir‐GLΦ‐β and Ir‐GLΦ‐α, mapping in the I‐A and I‐E/C subregions of the major histocompatibility complex, respectively. Previous studies have demonstrated that in order to generate a response to GLΦ, both gene products must be expressed in the antigen‐presenting cell (APC) but that neither responder allele has to be present in the responding T lymphocyte, provided that the T cell has matured in a responder environment. These results suggested that both gene products function as restricting elements in GLΦ presentation by APC. In this report, we provide further evidence for this model from experiments designed to test histocompatibility restrictions in antigen presentation at the I‐E/C subregion. Genetic identity at the I‐A subregion between T cells and APC was required for GLΦ presentation. To assess the requirements at I‐E/C, B10. A(5R) T cells (I‐Ab, I‐Ek) primed to GLΦ were stimulated in vitro with GLΦ‐pulsed spleen cells from F1 hybrids between C57BL/10 (B10: I‐Ab, I‐Eb) which made the cells compatible at I‐A, and a variety of B10 congenics bearing other H‐2 haplotypes. Although none of the parental spleen cells could present GLΦ to B10.A(5R) T cells, spleen cells from F1 hybrids between B10 and strains possessing H‐2I of k, d, p and r presented GLΦ, whereas hybrids with strains possessing H‐2I of f, q and s failed to present. This pattern of complementation for GLΦ presentation could not be explained on the basis of the responder status of the I‐E/C donating parental haplotypes nor by invoking inhibitory stimuli from mixed lymphocyte reactions induced by the Fl APC. Rather, the pattern correlated with the presence of the serologic marker Ia.7 coded for by the I‐E subregion of the complementing parental haplotype and the possession of an I‐E‐encoded a chain which has been shown by peptide mapping to be very similar in strains bearing the k, d, p and r haplotypes. These results suggest that the restriction element involved in the presentation of GLΦ to B10.A(5R) T cells is composed of a β chain encoded in I‐Ab and an a chain encoded in I‐E for which the allelic products of the k, d, p and r haplotypes are functionally equivalent. This correlation between structure and function represents the strongest evidence so far that Ia antigen‐bearing molecules are the Ir gene products.
Monoclonal antibody to a human leukocyte‐specific membrane glycoprotein probably homologous to the leukocyte‐common (L‐C) antigen of the rat
Authors: Dalchau Rosemarie , Kirkley Jean , Fabre John W. 
Published: February 2007

AbstractThe monoclonal antibody (F10–89–4) described in this study recognizes an antigen which by quantitative absorption analysis is absent from human brain, kidney, liver, heart, erythrocytes, platelets and normal serum, but is present on spleen, lymph node, chronic lymphatic leukemia cells, bone marrow, thymus and granulocytes at a ratio of 1 : 1 : 0.8 : 0.3 : 0.3 : 0.1, respectively. Analysis with the fluorescence‐activated cell sorter showed that 100% of thymocytes, lymph node lymphocytes, blood mononuclear cells and granulocytes carry the antigen, while 83% of bone marrow cells are positive. There was marked heterogeneity in the amount of labeling of thymocytes, with 3 major peaks. There was also heterogeneity of labeling of blood mononuclear cells and lymph node lymphocytes, with a weakly staining hump containing approximately 20% of the cells in the case of lymph node lymphocytes. Double labeling experiments demonstrated that the weakly staining cells of blood and lymph node were B lymphocytes, while frozen sections of thymus showed that the antigen was expressed most weakly in subcapsular cortical thymocytes, and most strongly on medullary thymocytes. Biochemical studies established that the antigen bound to lentil lectin columns, and sodium dodecyl sulfate polyacrylamide gel electrophoresis studies using NaB3 H4‐labeled blood mononuclear cells established that the antigen was a major glycoprotein of lymphocytes, and that its molecular weight was in the region of 190 000 to 215 000.
Presence of T145 on cytolytic T cell lines and their lectin‐resistant mutants
Authors: Conzelmann Andreas , Pink Richard , Acuto Oreste , Mach Jean‐Pierre , Dolivo Souzan , Nabholz Markus 
Published: February 2007

AbstractMurine cytolytic T cell lines have been analyzed for the expression of two surface glycoproteins called T 145 and T 130. T 145, known to be expressed by activated cytolytic T cells, is also expressed by such lines, but T 130, which has been described as a universal T cell marker, is not. Our results suggest a structural relationship between T 145 and T 130. Vicia villosa lectin, which binds selectively to T 145 of activated T cells and which is cytotoxic for cytolytic T cell lines, has been used to select lectin‐resistant mutants from these lines. Five independent lectin‐resistant mutants have been obtained. All of them are cytolytically active, bind up to 100‐fold less lectin than the parental lines, but still express T 145 or a closely related glycoprotein.
Cellular mechanisms of restricted immunoglobulin formation in the human neonate
Authors: Andersson Ulf , Bird Graham , Britton Sven 
Published: February 2007

AbstractThe functional capacity of human neonatal B lymphocytes has been investigated by in vitro methods using T lymphocyte‐dependent (pokeweed mitogen, PWM) and‐independent (Epstein‐Barr virus, EBV) polyclonal B cell activators. B cell activation of single cells was detected by class‐specific immunoglobulin (Ig) secretion using a reversed hemolytic plaque assay.It was found that neonatal B cells were triggered to secretion of IgM by EBV, with a magnitude comparable to adult levels, but that, in contrast to B cells from adults, they did not secrete any IgG. Cord lymphocytes did not secrete Ig although they displayed a sizable DNA synthetic response to PWM. Using cell separation and coculture experiments, it was shown that (allogeneic) adult T lymphocytes could restore cord B cell responsiveness to PWM and that cord T lymphocytes could not cooperate with adult B cells.In addition to this immaturity of cord T helper function for antibody synthesis, we found cells in the cord T cell‐enriched fraction which inhibited the polyclonal response of adult lymphocytes to both PWM and EBV. These lymphocytes suppressed adult B lymphocytes directly but appeared ineffective against neonatal B lymphocytes themselves. The nature of these suppressing cells and their possible role in the fetal/maternal relationship are a matter of speculation.