bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mouse alloantibodies capable of blocking cytotoxic T cell function. II. Further study on the relationship between the blocking antibodies and the products of the Lyt‐2 locus
Authors: Shinohara Nobukata , Hämmerling Ulrich , Sachs David H. 
Published: February 2007

AbstractThe specificity of mouse alloantibodies which blocked allogeneic killer cells has been confirmed as Ly‐2.2 using B 6 × C 3 H recombinant inbred (RI) strains. All of the RI strains tested were sensitive to the cell‐mediated lymphocytotoxicity (CML)‐blocking effect of our C3 H anti‐B 10.BR antisera and also carried the Lyt‐2b allele. This result and studies using Lyt‐2‐congenic strains firmly localized the genes encoding the target antigen of CML‐blocking antibodies in or near the Lyt‐2 locus. In addition, a monoclonal anti‐Lyt‐2.2 antibody was found to block the CML reaction of B 6 killer cells, but not that of B 6 Ly‐2.1 killers. Blocking antibodies to one allele blocked killing by Lyt‐2‐heterozygous F1 killer cells, but the inhibition curve reached a plateau at a significantly lower level than that seen on the killer cells of the sensitive parent. Our results thus suggest that Lyt‐2 antigens are of functional significance on killer T cells, but do not reveal whether or not that significance involves the T cell receptor.
Mechanisms of antigen‐induced blockade of immune response and cyclophosphamide‐promoted tolerance to Salmonella typhi Vi antigen
Authors: Prigozhina Tatyana B. , Fontalin Lev N. 
Published: February 2007

AbstractBlockade of the immune response, caused by a high dose of Salmonella typhi Vi antigen (200 μg i.v.) and cyclophosphamide (CY)‐induced tolerance to Vi antigen, were analyzed.The results of the study show that blockade of the immune response cannot be attributed to masking of the response resulting from neutralization of antibodies by the excess of non‐cell‐bound antigen. A high dose of Vi‐antigen induced triggering and proliferation of specific B precursors but reversibly suppressed synthesis or secretion of antibody by plaque‐forming cells.A single injection of CY (200 mg/kg i.p.) 2 days after a high dose of Vi antigen markedly prolonged the antigen‐induced state of unresponsiveness. CY‐induced tolerance to Vi antigen is due to elimination or long‐term inactivation of specific B precursors. Dissimilarities in the characteristics of immune response blockade and CY‐induced tolerance are discussed as well as their possible implications for the mode of action of CY.
Effect of exogenous lipids and lipoproteins on the primary immune response in vitro
Authors: Shine Thomas E. , Little J. Russell , Shore Virgie , Medoff Gerald , Abegg Ann 
Published: February 2007

AbstractCholesterol and certain lipoproteins have regulatory effects on the primary immune responses of murine spleen cells in vitro. The plaque‐forming cell (PFC) responses to sheep red blood cells or trinitrophenylated Brucella abortus were studied in complete, lipid‐depleted or lipoprotein‐reconstituted media. The requirement for exogenous low density lipoprotein (LDL) and its cholesterol moiety was established by comparison of the yield of PFC in cell cultures deprived of lipoproteins with that in cultures to which specific classes of lipoproteins were added. The spleen cells in complete medium yielded about 10‐fold greater PFC responses than cells in lipoprotein‐deficient medium. In lipoprotein‐deficient media, human LDL completely reversed the decreased immune response, LDL lipids and free cholesterol partially reversed the deficit, the human high density lipoproteins and an apo B phospholipid complex were ineffective. In complete media, cholesterol at higher concentrations (100–200 μg/ml) and LDL lipids partially inhibited the primary immune response. Exogenous cholesterol was required for the in vitro response to both thymus‐dependent and thymusindependent antigens.
T cell factor (interleukin 2) allows in vivo induction of T helper cells against heterologous erythrocytes in athymic (nu/nu) mice
Authors: Stötter Hans , Rüde Erwin , Wagner Hermann 
Published: February 2007

AbstractMice carrying the nude mutation (nu/nu) lack a functioning thymus and do not contain detectable levels of immunocompetent T cells. We now report that nu/nu mice do have lymphocytes which can be activated in vivo by heterologous erythrocytes and a Lyt‐1 T cell‐derived factor (interleukin 2) to generate T helper cells. Thus, a lymphokine is described which is able to restore in vivo T helper cell immunocompetence of nu/nu mice. The data may suggest that nu/nu mice contain a low number of T lymphocytes influenced by the cystic remnant of the nu/nu thymus anlage. Alternatively, the data imply that interleukin 2 circumvents the requirement of a thymus during ontogeny of T lymphocytes.
Stimulation of murine B cells with anti‐Ig antibodies: dominance of a negative signal mediated by the Fc receptor
Authors: Tony Hans‐Peter , Schimpl Anneliese 
Published: February 2007

AbstractWhile soluble intact rabbit anti‐mouse x chain antibodies (RaMK) fail to stimulate [3H] thymidine incorporation in B cells of young mice, the F(ab')2 fragments thereof are stimulatory. This stimulation can be abrogated by the addition of soluble intact RaMK, pointing at the dominance of a negative signal mediated by intact antibodies, probably via their Fc portion. Blocking the interaction between intact antibody, and the Fc receptor of B cells by staphylococcal protein A renders the intact antibodies also stimulatory. Protein A itself is not mitogenic in this system nor does its addition influence B cell activation induced by rabbit F (ab')2 anti‐mouse x chain antibodies. The data indicate that the Ig receptor of murine B cells can serve as a triggering receptor provided the negative signal mediated by cross‐linkage involving the B cells' Fc receptor is avoided.
Kinetics of intracellular killing of Staphylococcus aureus and Escherichia coli by human granulocytes
Authors: Leijh Peter C. J. , van den Barselaar Maria T. , Dubbeldeman‐Rempt Ivonne , van Furth Ralph 
Published: February 2007

AbstractThe intracellular killing of Staphylococcus aureus and Escherichia coli by human granulocytes was investigated independently of the ingestion of these bacteria. Granulocytes were allowed to phagocytose preopsonized bacteria for only 3 min, after which the noningested bacteria were removed by differential centrifugation and 2 washes. With this technique, the number of viable cell‐associated bacteria at the start of the assay, determined after lysis of the granulocytes, includes about 80% intracellular bacteria.Intracellular killing depends on (a) the temperature (no killing occurring at 4°C, maximal killing at 33–39 °C, and a decrease in the capacity of the granulocytes to kill ingested bacteria at temperatures above 42 °C), and (b) the number of bacteria ingested (after phagocytosis at bacteria‐to‐cell ratios of 100 : 1 and 1000 : 1, not all of the ingested bacteria are killed, whereas after phagocytosis at lower bacteria‐to‐cell ratios, almost all ingested bacteria are killed). To determine the maximum number of bacteria that can be killed by granulocytes, intracellular killing was measured after phagocytosis of bacteria at various bacteria‐to‐granulocyte ratios in the presence of phenylbutazone, a drug which inhibits killing during the ingestion period. Phenyl‐butazone proved to be a useful tool in the study of intracellular killing, since this drug provides a reversible inhibition of the killing when granulocytes are incubated in its presence for up to 3 min, whereas after longer incubation, the inhibitory effect is irreversible. Calculation based on the data obtained in this study gave maximum rates of intracellular killing amounting to 3.7 × 105 bacteria/5 × 106 granulocytes/min for Staph. aureus and 8.5 × 105 bacteria/5 × 106 granulocytes/min for E. coli. Using the rate of intracellular killing after phagocytosis at a bacteria‐to‐granulocyte ratio of 1 : 1 and the rate of ingestion obtained in an earlier study, we were able to compute the theoretical numbers of viable extracellular not (yet) ingested, viable intracellular, killed intracellular and total intracellular bacteria. The theoretical curves fit well with the experimental data.
Effect of virus‐induced interferon on the antibody response of suckling and adult mice
Authors: Vignaux Françoise , Gresser Ion , Fridman Wolf H. 
Published: February 2007

AbstractContinued administration of potent virally induced mouse interferon (IFN type I) preparations to suckling mice resulted in an inhibition of the primary antibody response to sheep erythrocytes (14‐day‐old mice). When slightly older suckling mice were immunized (17 days old), a delay (about 2 days) in the kinetics of the response was observed, but the amplitude of the response was similar in both control and IFN‐treated animals.In adult mice, potent IFN preparations did not inhibit the antibody response under a variety of experimental conditions (different doses of IFN, schedules of treatment, routes of injection, times of assay). Although IFN does inhibit the in vitro antibody response, we conclude that under most experimental conditions, injection of IFN type I is not immunosuppressive in adult mice. When administered after immunization, IFN clearly enhanced the primary antibody response. It is of interest that IFN, a product of viral infection, enhances in vivo those components of the immune system that have been implicated in the host response to viral infections (i.e. delayed‐type hypersensitivity, natural killer cell and macrophage activity, expression of lymphocyte membrane molecules), and, as is shown here, the primary antibody response.
Characterization of mouse thoracic duct B lymphocytes I. Evidence of functional heterogeneity
Authors: Freitas António A. , Coutinho António A. 
Published: February 2007

AbstractThoracic duct lymphocytes (TDL) from C 3 H/Tif and BALB/c mice were studied for their in vitro reactivity to the B cell mitogens lipopolysaccharide (LPS) and lipoprotein (LP). Roughly 4% and 10% of the surface immunoglobulin (Ig)‐positive cells in these populations could be stimulated by LPS and LP, respectively, to generate clones of IgM‐secreting cells. Among LPS‐reactive B cells, roughly 30% developed into clones which also produced IgG3 or IgG2, while only a very small fraction (1–2%) of all precursors could give rise to clones secreting IgG1 and IgA. Freshly collected TDL from some batches of C 3 H/HeJ mice displayed a high proportion of Ig‐containing B cell blasts (5–10%), which did not secrete enough Ig to be detected as plaque‐forming cells (PFC). These cells, however, under appropriate culture conditions and stimulated by LP (but not by Nocardia mitogen), differentiated to PFC of the various Ig classes without dividing.
Macrophage handling of soluble immune complexes Use of specific inhibitors to study the biochemical events involved in complex catabolism
Authors: Leslie Robert G. Q. 
Published: February 2007

AbstractEvents involved in the macrophage catabolism of soluble immune complexes have been investigated using quantitative assays of complex ingestion and digestion, and specific disruptors of microtubule and microfilament organization (colchicine and cytochalasin B) a local anesthetic (Lidocaine), and two serine esterase inhibitors (TLCK and TPCK) of which one (TPCK) is a reported inhibitor of phagocytosis (Nagai, K. et al., FEBS Lett. 1978. 92: 299). Marked selective inhibition of ingestion, pinosome‐lysosome fusion and complex degradation was observed in the presence of cytochalasin B. Lidocaine and TLCK, respectively. The biochemical basis of the selective action of these inhibitors is discussed.
Selective suppression of the cytotoxic T cell response to influenza virus in mice
Authors: Leung Kwok‐Nam , Ashman Robert B. , Ertl Hildegund C. J. , Ada Gordon L. 
Published: February 2007

AbstractMice injected with inactivated (UV light‐irradiated) influenza virus produce specific antibody, become sensitized for a delayed‐type hypersensitivity reaction, but do not generate specific cytotoxic T (Tc) cells. If injected 4–5 days later with infectious virus, the formation of Tc cells is suppressed by > 90%. If A strain viruses are used, the suppression observed is cross‐reactive within A strain viruses but does not extend to B/LEE or to Sendai virus. Serum from mice injected with UV‐irradiated virus contains antibodies which on adoptive transfer can inhibit Tc cell formation when infectious homologous virus is used to challenge the recipients. Spleen cells from the same mice, upon adoptive transfer, also inhibit (50–70%) Tc cell formation if transferred within 24 h of injection of infectious virus, and the specificity pattern observed is cross‐reactive within A strains. The activitiy of the cells mediating suppression is destroyed by monospecific anti‐Thy‐1.2 antibody and complement. The immune cells require I region sharing between donor and recipient mice for their suppressor activity to be effective. (There is also a partial requirement for K. D region sharing, but the possible rejection of transferred cells is not excluded.) Dilution assays in which clonal expansion of Tc precursors is used to estimate their frequency and the presence of T helper (Th) cells indicate that suppressed mice possess Tc precursors and primed cells which, upon restimulation, act as Th cells. Furthermore, injection of irradiated Th cells with inactivated virus does not significantly reduce the ensuing suppression.
Production of auto‐anti‐idiotypic antibody during the normal immune response. IV. Studies of the primary and secondary responses to thymus‐dependent and‐independent antigens
Authors: Goidl Edmond A. , Schrater A. Faye , Thorbecke G. Jeanette , Siskind Gregory W. 
Published: February 2007

AbstractWe have previously shown that hapten‐augmentable plaque‐forming cells are cells whose secretion of antibody is inhibited by the binding of auto‐anti‐idiotype antibody to cell surface antigen receptors. Using hapten augmentation of plaque formation, it was shown in the present report that auto‐anti‐idiotype antibodies are produced during the primary and secondary responses to both thymus‐dependent und thymus‐independent antigens. In the secondary response to the T‐independent antigen trinitrophenylated Ficoll, the rate of appearance of auto‐anti‐idiotype antibody was faster, and the number of hapten‐augmentable plaques was greater than in the primary response suggesting an anamnestic auto‐anti‐idiotype response. With the T‐dependent antigen, trinitrophenylated bovine gamma‐globulin, the kinetics and magnitude of the auto‐anti‐idiotypic antibody response were relatively similar in the primary and secondary responses. However, a lower concentration of hapten was required to reveal the hapten‐augmentable plaques in the secondary response. This is in keeping with the usual finding that secondary antibody to T‐dependent antigens is of very high affinity. Both direct and indirect hapten‐augmentable plaque‐forming cells were detected suggesting that the secretion of both IgM and IgG antibodies is regulated by auto‐anti‐idiotype antibodies. The data are consistent with a role for auto‐anti‐idiotype antibody in the normal down‐regulation of the immune response as suggested by Jerne's network hypothesis.
Cytotoxic T cell responses to haptenated cells III. Isolation and specificity analysis of continuously growing clones
Authors: Haas Werner , Mathur‐Rochat Jacqueline , Pohlit Helmut , Nabholz Markus , Von Boehmer Harald 
Published: February 2007

AbstractVarious procedures were used to derive continuously growing cytotoxic T lymphocyte (CTL) clones from a primary culture containing responder cells from immunized mice and 3‐(p‐sulfophenyldiazo)‐4‐hydroxylphenyl acetic acid (SP)‐or fluorescein isothiocyanate (FL)‐coupled stimulator cells. It seems likely that CTL have to undergo some change, possibly genetic, to be able to grow continuously in T cell growth factor conditioned medium in the absence of any stimulator or filler cells. The most convenient and reliable procedure to generate CTL clones with different specificities was to establish from several aliquots of a primary culture cell populations continuously growing in medium conditioned with T cell growth factor(s). Clones with different specificities segregated in the different populations. SP‐and FL‐specific CTL clones restricted to H‐2Kk, and H‐2Dd and two FL‐specific CTL clones with no apparent H‐2 restriction are described.
Sequential expression of functions during macrophage differentiation in murine bone marrow liquid cultures
Authors: Neumann Christine , Sorg Clemens 
Published: February 2007

AbstractIn the presence of a colony‐stimulating factor, murine bone marrow cells proliferate and differentiate into macrophages. This culture system was taken as a model to study the expression of various functions by macrophages in the course of maturation. Several tests were performed daily and in parallel from the same batch of cells. It was found that certain functions were expressed early and were also characteristic for mature macrophages such as Fc receptors, phagocytosis of latex beads and unspecific' esterase activity. Other functions appeared and disappeared in an ordered sequence, such as the response to macrophage migration inhibitory factor and chemotactic factor as well as the production of interferon and of plasminogen activator. The time course of functional expression was strongly dependent on proliferation of precursor cells as well as proliferation of differentiated macrophages. It is suggested that the phenotypic expression of functions during differentiation is the basis for the functional heterogeneity of macrophages.
In vitro evidence for T‐B lymphocyte collaboration in the clawed toad, Xenopus
Authors: Blomberg Bonnie , Bernard Claude C. A. , Pasquier Louis Du 
Published: February 2007

AbstractRequirements for an in vitro secondary antibody response to the soluble antigens dinitrophenylated keyhole limpet hemocyanin and dinitrophenylated fowl gamma‐globulin are described for the clawed toad, Xenopus. Priming of both hapten and carrier‐specific cells is required in order to obtain good responses to the hapten. The carrier‐reactive (“helper”) cells do not adhere to nylon wool, are X ray‐resistant and surface Ig‐negative. The cell adherence and X ray sensitivity characteristics of these Xenopus “T” cells and their ability to generate a mixed lymphocyte response, allogeneic cytotoxic and helper activities, are identical to those of thymus‐derived (T) cells in higher vertebrates. The hapten‐reactive, antibody‐secreting cell precursors are nylon‐adherent, X ray‐sensitive and surface Ig‐positive. In the absence of other distinguishing serological markers for T cells in frogs, and considering the thymus dependency of the helper activity described here, the evidence presented is interpreted as demonstrating the requirement for antigen‐specific T‐B cell cooperation in response to soluble protein antigens in vitro for Xenopus.
Suppression of mitogen‐induced peripheral B cell differentiation by soluble Fcγ receptors released from lymphocytes
Authors: Lethibichthuy  , Samarut Christiane , Brochier Jean , Fridman Wolf Herman , Revillard Jean‐Pierre 
Published: February 2007

AbstractSoluble receptors for FcIgG released from unstimulated human peripheral blood lymphocytes were isolated by affinity chromatography on Sepharose 4B‐IgG. This material was shown to interfere with the differentiation of peripheral blood B cells into Ig‐secreting cells in cultures stimulated with pokeweed or Nocardia opaca extracts. Neither cell viability nor [3H]thymidine incorporation were altered, but the number of Ig‐eontaining cells and that of Ig‐secreting cells were decreased. These effects were dose‐related. They were found to be associated with Fc IgG‐binding soluble material, since absorption on Sepharose 4B‐IgG but not on pepsin‐digested F(ab')2 fragments removed the inhibitory activity. This suppressor factor, released by unstimulated lymphocytes, may represent a human analogue of murine immuno‐globulin‐binding factor (IBF) produced by alloactivated T cells.
Ontogeny of B lymphocyte function VIII. Failure of thymus cells from aged donors to induce the functional maturation of B lymphocytes from immature donors
Authors: Szewczuk Myron R. , Dekruyff Rosemarie H. , Goidl Edmond A. , Weksler Marc E. , Siskind Gregory W. 
Published: February 2007

AbstractThe role of thymus cells in mediating a step in the ontogeny of the capacity of the B cell population to produce a heterogeneous, high‐affinity, primary, plaque‐forming cell (PFC) response was further investigated. It was shown that the thymus acquires the capacity to facilitate this step in B cell differentiation between 3 and 4 weeks of age in C 57 BL/6 mice. This corresponds to the age at which the splenic B cell population of these mice naturally acquires the capacity to produce high‐affinity PFC. The findings are thus consistent with the view that the thymus regulates this step in the differentiation of the B cell population. It was further shown that the ability of thymus cells to facilitate the maturation of the B cell population decreases with age and is already markedly reduced in 30‐week‐old, long‐lived, C57 BL/6 mice. A qualitative or quantitative decrease in thymic function may thus be responsible for age‐related changes in the function of the B cell population.
Regulation of delayed‐type hypersensitivity V. Suppressor cell memory in antigen‐specific suppression of delayed‐type hypersensitivity to sheep erythroeytes
Authors: Liew Foo Y. , Howard James G. 
Published: February 2007

AbstractMice primed i. v. with 109 sheep red blood cells (SRBC) produce antigen‐specific T suppressor (Ts) cells which inhibit both the induction and the expression of delayed‐type hypersensitivity (DTH). These Ts cells are detectable in the spleen and lymph nodes 3–5 days after priming but are largely absent by 6 days. The transient detect‐ability of the Ts cells contrasts sharply with the profound antigen‐specific suppression which persists in primed donor mice for at least a year.Evidence is presented that this long‐term impairment of DTH is maintained, at least in part, by memory Ts cells which are Thy‐1+, cyclophosphamide‐resistant and antigen‐specific. Although they appear to be co‐induced with the short‐lived primary Ts cells and localize initially in the lymphoid organs, they are present in the long‐lived circulating pool of T cells and can be adoptively transferred by celomic parabiosis. Memory Ts cells are readily reactivated by lower doses of SRBC which would induce T effector cells rather than Ts cells in naive animals. Reactivated memory Ts cells seem to generate a population of antigen‐specific secondary Ts cells which again localizes in the lymphoid organs and can adoptively suppress the induction and expression of DTH to SRBC.
IgG Fc‐binding receptors on spermatozoa
Authors: Sethi Krishan K. , Brandis Henning 
Published: February 2007

AbstractThe ability of human and mouse spermatozoa to bind immunoglobulin to their surfaces was investigated by a binding assay using radioiodinated Ig. The results suggest that spermatozoa of both human and mouse origin possess Fc receptors, i.e. they have the ability to bind Fcγ region. This association of Fc‐binding receptor activity on spermatozoa surfaces is likely to raise some technical problems in certain conventional assays used to monitor the presence of membrane antigen(s) on spermatozoa.