bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation, characterization and amino acid sequence studies of the cyanogen bromide fragments of the H‐2 Dd glycoprotein
Authors: Nairn Roderick , Nathenson Stanley G. , Coligan John E.
Published: February 2007

The papain‐solubilized fragment of the H‐2Dd antigen, representing the NH2‐terminal 80% of the native glycoprotein, can be fragmented into five polypeptides using CNBr cleavage. These fragments have been isolated, characterized and subjected to amino acid sequence analysis using radiochemical microtechniques. It was possible to align these CNBr fragments by comparison of their NH2‐terminal amino acid sequence with the known amino acid sequence of the H‐2 Kb molecule. Thus, the NH2‐terminal fragment, D, contains 23 residues and is followed by a glycopeptide, fragment C, of 75 residues. Following fragment C are three fragments held together by disulfide bonds: fragment b 4, which has 40 amino acid residues, a second glycopeptide, fragment b 2, of 90 residues, and fragment b 3, a peptide of approximately 55 residues which terminates at the site of papain cleavage. The complete amino acid sequence of the NH2‐terminal CNBr fragment, D, has been determined, and this is presented here along with sequence data for the NH2‐terminal 30 residues of each of the other four CNBr fragments of the papain fragment of H‐2Dd. A total of 146 positions have been examined in the approximately 280‐residue H‐2D molecule, and a total of 127 residues have been positively determined. Most of the unassigned positions may be tentatively assigned as Asp or Asn, the only amino acids so far not incorporated in radiolabeled form by our metabolic labeling procedures into the H‐2 Dd molecule. Comparison of the sequence data obtained for the H‐2 Dd molecule to data available for other histocompatibility antigens revealed homologies of approximately 90% with H‐2 Kb and H‐2 Ld, and approximately 75% with HLA‐B 7 and HLA‐A2.
T cell‐mediated cytotoxic immune responsiveness of chimeric mice bearing a thymus graft fully allogeneic to the graft of lymphoid stem cells
Authors: Wagner Hermann , Röllinghoff Martin , Rodt Hans , Thierfelder Stephan
Published: February 2007

Fully allogeneic, chimeric mice were established by adult thymectomy of (A × B) F1animals, grafting parental A‐type thymus under the kidney capsula, followed by lethal (900 rd) irradiation and reconstitution with B parental‐type bone marrow cells treated with xenogeneic anti‐T cell antiserum plus complement. Following in vivo sensitization with inactivated Sendai virus (SV) suspensions, no virus‐specific T cells could be detected within the spleen cells of the mice. Upon stimulation with third‐party allogeneic cells in a primary mixed lymphocyte culture, spleen cells of all animals generated alloreactive cytotoxic T lymphocytes (CTL). More interestingly, upon secondary in vitro stimulation with inactivated SV‐conjugated B‐type stimulator cells, B‐type‐restricted, virus‐specific CTL were inducible in each case. Upon restimulation with SV‐conjugated A‐type stimulator cells, A being the H‐2 type of the grafted thymus, T cells of some but not all mice generated A‐type‐restricted, virus‐specific CTL. The data suggest that in allogeneic, chimeric mice virus‐specific CTL can be induced. Moreover, virus‐specific CTL, restricted to the H‐2 type of the lymphoid stem cell inoculum, are more readily inducible than those restricted to the H‐2 type of the allogeneic thymus.
Idiotypic specificities which arise naturally in rabbits following allotype suppression of the major VH subgroup
Authors: Roux Kenneth H. , Gilman‐Sachs Alice , Dray Sheldon
Published: February 2007

In contrast to normal IgG, some of the IgG molecules, which appear in compensation as a result of allotype suppression of IgG molecules of the major VH subgroup (a locus), were found to have an easily identifiable idiotypic specificity. For each of three donors' IgG, a different idiotypic specificity was present, and each idiotypic specificity was found on the Fab, as expected, but not on the Fc fragment. Further analysis of the IgG of one donor revealed that the idiotypic specificity was present on 15% of the Fab γ fragments. The idiotypic specificity was expressed on IgG which also bore an allotypic specificity of the y locus VH subgroup of IgG which comprised most (72%) of the total compensatory IgG. This suggests that suppression of clones synthesizing the a locus major VH subgroup results in compensation by minor VH subgroup clones more limited in variability. These clones may then proliferate to synthesize larger amounts of IgG bearing the same idiotypic specificity which thereby becomes more easily detectable by immunization of rabbits.
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

The 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

Blockade 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

Cholesterol 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

Mice 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

While 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

The 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

Continued 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

Thoracic 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

Events 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

Mice 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

We 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

Various 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

In 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

Requirements 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

Soluble 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

The 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

Mice 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

The 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.
The immune response to human type III and type V (AB2) collagen: antigenic determinants and genetic control in mice
Authors: Kemp John D. , Madri Joseph A.
Published: February 2007

The genetic influences on the specific IgG antibody response to helical antigenic determinants of native soluble type III and V (AB2) human collagen have been studied in mice. H‐2‐linked Ir genes have been detected for each of these collagens, as have background effects. The alleles controlling high antibody responses can be distinguished from those previously described for bovine collagen type I and type I propeptide. Apparent two‐gene complementation in the response to type V (AB2) may indicate that this antigen will be a useful probe in further studies of the complex nature of antigen presentation for T cell recognition. The present studies may facilitate the production of specific, high‐affinity monoclonal antibodies for the human collagens which, in turn, will facilitate the study of connective tissue biology and pathology.
Demonstration of T lymphocytotoxic human fetal antibody against maternal T and concanavalin A‐inducible adult T cells in cord IgM
Authors: Miyagawa Yukiaki , Komiyama Atsushi , Akabane Taro
Published: February 2007

To clarify reasons of the constant presence of IgM in human cord blood, some functions of this immunoglobulin class were analyzed. Cord IgM was collected from cord blood, and the cord IgM F(ab')2 fragment was obtained by trypsin cleavage. Maternal T and adult T cells were stained with fluorescein isothiocyanate (FITC)‐conjugated cord IgM and FITC‐cord F(ab')2μ. Cord IgM, unlike cord IgG, bound to about one‐third of maternal and one‐fourth of adult T cells and killed them, but it killed only a small proportion of the B cells. However, adult F(ab')2μ did not kill these cells. Cord T cells were not killed by cord IgM. Thus, it is apparent that cord IgM contains cytotoxic antibodies against maternal and adult T cells. T lymphocy‐totoxic fetal antibody (TLFA) may be largely responsible for the absence of maternal T cells in cord blood. The percentage of [3H]thymidine incorporation into concanavalin A‐induced adult mononuclear cells treated with cord IgM containing TLFA was 56.0 ± 17.9% (p<0.01) and that into pokeweed mitogen‐induced cells treated with the cord IgM preparation was 100.3 ± 17.8% (p>0.05) indicating the possibility that TLFA might kill a certain subset(s) of T cells.
Genetic control of T helper cell function in the clawed toad Xenopus laevis
Authors: Bernard Claude C. A. , Bordmann Gérard , Blomberg Bonnie , Pasquier Louis Du
Published: February 2007

The genetic control of the collaboration between Xenopus T and B cells has been analyzed in vitro using cells from five strains of major histocompatibility complex‐defined Xenopus.

When carrier (fowl gamma‐globulin)‐primed T cells and hapten (dinitrophenylated keyhole limpet hemocyanin)‐primed B cells differed by minor histocompatiblity antigens or by only one haplotype of the major histocompatibility complex, the collaboration was efficient in the sense that large numbers of plaques, low‐molecular weight antibodies and high‐affinity IgM antibodies could be recorded in the cultures challenged with dinitrophenylated fowl gamma‐globulin. However, when T and B cells differed at both alleles of the major histocompatibility complex, lower numbers of plaques were obtained, no low‐molecular weight anti‐hapten antibodies could be detected, and the IgM antibodies that were sometimes synthesized were of low affinity. This suggests that the major histocompatibility complex, or a gene linked with it, affects the collaboration between Xenopus T and B cells in a way perhaps similar to that described in mammals.
Inhibition of secondary IgG responses by N‐acetyl‐D‐galactosamine
Authors: Tomaska Luba D. , Parish Christopher R.
Published: February 2007

A range of monosaccharides were tested for their ability to inhibit a variety of in vitro immune responses. The most striking specific inhibition was produced by N‐acetyl‐D‐galactosamine (GalNAc). This sugar strongly inhibited the secondary IgG antibody response to two different hapten‐carrier systems, but had no effect on primary and secondary IgM responses, generation of cytotoxic T cells to alloantigens and mixed lymphocyte reactions. By exposing secondary antibody cultures to GalNAc for varying periods of time, it was observed that GalNAc only exerted its inhibitory effect on day 4 of the culture, the day when IgG plaque‐forming cells first appeared. Furthermore, GalNAc could override the action of T helper factor in T cell‐depleted cultures. Collectively, these data indicate that GalNAc inhibits the initiation of IgG synthesis probably by blocking the interaction of a helper factor for IgG synthesis with its target cell.
Histocompatibility requirements for T cell help in specific in vitro antibody responses to influenza virus by human blood lymphocytes
Authors: Callard Robin E. , Smith Caroline M.
Published: February 2007

Specific antibody responses to influenza virus were obtained in vitro from human blood mononuclear cells (PBM). The response was T cell‐dependent, as shown by separation of PBM into E rosette‐positive (E+) and ‐negative (E−) populations. The histocompatibility requirements for T‐B cell interactions in this response were analyzed by recombining E− and E+ fractions from donors with varying degrees of HLA compatibility. No antibody formation was obtained from any allogeneic combination except for the special case of HLA identical siblings. As these experiments included combinations with shared or identical HLA‐DR specificities, it was unlikely that genetic restriction alone could account for the failure of T‐B cell collaboration. Evidence that suppression was responsible for the lack of antibody formation was obtained from experiments in which allogeneic E+ cells profoundly depressed specific antibody responses of intact PBM. In contrast, no such suppression was seen in pokeweed mitogen‐driven polyclonal Ig synthesis for which there are no major histocompatibility complex requirements for T cell help. The suppressor activity of allogeneic E+ cells was found to be radiation‐sensitive. By irradiating E+ cells, it was, therefore, possible to test for T cell help across an HLA barrier without unwanted suppressor effects. Under these conditions, (irradiated) E+ cells were able to collaborate with allogeneic E− cells even with no HLA alleles in common. This was true even when autologous monocytes were depleted from the helper E+ population. Supernatants collected from antigen‐driven cultures of allogeneic E− and E+ cells were able to replace helper T cells in the specific antibody response to influenza virus. The apparent lack of genetic restriction in these responses might, therefore, be explained by the production of a nonrestricted helper factor.
Tolerogenic or immunogenic activity of hapten‐conjugated polysaccharides correlated with cellular localization
Authors: Humphrey John H.
Published: February 2007

Dinitrophenylated (DNP) conjugates of Ficoll, hydroxyethyl starch, levan, dextran, type 3 pneumococcal capsular polysaccharide SIII, pectin, alginic and hyaluronic acid at various epitope densities were tested for their capacity to inhibit secondary IgG anti‐DNP antibody responses using an in vivo transfer system. Some aminobenzylarsonate conjugates were examined similarly. Conjugates of the acidic polysaccharides were markedly more effective than those of uncharged polysaccharides. Conjugates with high epitope densities were particularly tolerogenic. DNP conjugates of Ficoll and hydroxyethyl starch elicited prolonged IgM responses over a wide dose range, and there are indications in the literature that conjugates of dextran do likewise. All the polysaccharide conjugates, labeled with radioiodine, persisted in the body for long periods (half‐lives 8.5–63 days), and all were cleared rapidly from, but remained detectable in the blood for many days. Gross tissue distributions varied markedly from one conjugate to another, and autoradiography revealed unexpected differences in cellular localization. Despite substantial retention in the liver, some uncharged polysaccharides were localized only in parenchymal and not in Kupffer cells. In the spleen, only the acidic polysaccharides were predominantly localized in red pulp macrophages, and the neutral polysaccharides were detectable exclusively, and in the case of Ficoll, hydroxyethyl starch and some dextrans very intensely in macrophages of the marginal zone of the white pulp. It is suggested that retention of thymus‐independent antigens in marginal‐zone macrophages favors, whereas trapping in red‐pulp macrophages diminishes immunogenicity, and that tolerogenic effectiveness depends upon a balance between tolerization of B cells by free antigen and stimulation by antigen presented by marginal‐zone macrophages. The distinction between functionally different macrophages in the spleen is elaborated in the following report.
Alteration of clonal profile II. Studies on the capacity of BALB/c splenic B cells to perpetuate responsiveness to phosphorylcholine and T15 idiotypic dominance
Authors: Quintáns José , Loken Michael R. , Quan Zoe S. , Dick Robert F. , Regueiro Benito
Published: February 2007

(CBA/N × BALB/c)F1 hybrid male mice are unable to mount anti‐phosphorylcholine (PC) plaque‐forming cell (PFC) responses because they carry the CBA/N X‐linked immune defect of B lymphocyte differentiation. Transplantation of splenic B cells from BALB/c mice restores responsiveness to thymus‐dependent and thymus‐independent PC antigens up to 8 months after cell transfer. Cytotoxicity studies demonstrate the donor origin of PFC generated in reconstituted (CBA/N × BALB/c)F1 mice. Although responsiveness to PC is restored permanently, a shift in idiotype expression that leads to the loss of T 15 idiotypic dominance 3 months after cell transfer can be detected. This shift originates from Ig− cells because Ig+ splenic cells purified in a fluorescence‐activated cell sorter maintain T15 dominance. Therefore, the Ig+ cells have a remarkable capacity to maintain responsiveness to antigens and can perpetuate idiotypic dominance if the stem cell pool is removed.
Effect of anti‐Lyb3 antiserum on poly (L‐glutamic acid, L‐lysine)‐induced B cell tolerance
Authors: Sherr David H. , Huber Brigitte T. , Gershon Richard K. , Benacerraf Baruj , Dorf Martin E.
Published: February 2007

The effect of anti‐Lyb3 antiserum on antigen‐specific B cell tolerance was investigated. The intraperitoneal injection of the nonimmunogenic copolymer L‐glutamic acid60, L‐lysine40 (GL) specifically reduces the ability of murine B cells to form GL‐specific plaque‐forming cell responses following challenge with the immunogenic conjugate of GL coupled to fowl gamma‐globulin. It was found that this tolerance could be reversed or blocked by the intravenous injection of microliter quantities of anti‐Lyb3 antiserum. However, this dose of antiserum neither reversed T cell tolerance induced with protein‐coupled syngeneic erythrocytes nor induced tolerized B cells to secrete antibody. The results suggest that B lymphocytes can be rescued from GL‐induced tolerance soon after induction and that Lyb3 determinants may play a functional role in the activation of antigen‐specific B lymphocytes.
Allotype suppression in the chicken II. Suppression in homozygous chickens with antiallotype antibody and allotype‐disparate B cells
Authors: Ratcliffe Michael J. H. , Ivanyi Juraj
Published: February 2007

Injection of heterozygous (M‐13/M‐1b, G‐1g/G‐1i) B 14‐line chickens with antisera directed against either IgM‐1a or IgM‐1b induced suppression of the relevant IgM‐1 and genetically linked IgG‐1 allotypes, whereas a mixture of anti‐M‐1a and anti‐M‐1b antibodies failed to produce allotype suppression. Injection of anti‐M‐1 antiserum into M‐1 homozygous chickens induced only a transient delay of a few days in the appearance and rise of serum IgM‐1 levels. However, suppression of host allotypes was induced by injecting M‐1, G‐1 homozygous neonatal or embryonal recipients with anti‐M‐1 antisera together with B locus‐histocompatible allotype‐disparate spleen, bone marrow or bursal cells. The active cell type were donor B cells, which established chimerism in the injected hosts, whereas peripheral blood T lymphocytes from agammaglobulinemic donors were ineffective. Allotype suppression was attributed to a homeostatic control mechanism which is exerted by normal B cells (but not T cells) over B cell recruitment in anti‐M‐1 antibody‐treated, immature hosts.
IgE‐induced histamine release from rat basophilic leukemia cell lines: isolation of releasing and nonreleasing clones
Authors: Barsumian Edward L. , Isersky Chaviva , Petrino Marianne G. , Siraganian Reuben P.
Published: February 2007

The rat basophilic leukemia (RBL) cell lines were cloned and the various sublines compared for their chromosome number, IgE‐mediated histamine release and for IgE surface receptors. It was found that cell lines started from tumors at different times vary in both their chromosome number and their ability to release histamine by an IgE‐mediated reaction. RBL‐I and III have ∼ 44 chromosomes and did not respond to an IgE‐mediated reaction, whereas RBL‐II and RBL‐IV have 68–73 chromosomes and showed moderate levels of histamine release (percent release x̄ = 5 ± 2 and 10 ± 4, respectively). The cloning of the RBL‐IV line resulted in some sublines which were excellent histamine releasers (range 39–100%) and some which were relatively refractory (< 10%) to IgE‐mediated histamine release. These clones did not differ significantly in chromosome number. Recloning the releasing lines gave rise to poor releasers, whereas the recloning of poor releasers did not produce good releasers indicating that the mutational drift in culture is toward loss of histamine‐releasing capacity. The number of IgE receptors and the rate of IgE association and dissociation were similar for the different cell lines. The study failed to disclose significant molecular weight differences in the IgE receptor from the various clones and sublines indicating that the failure to release probably does not reside in the receptor. The various cloned sublines are phenotypically stable, and the isolation of excellent histamine‐releasing sublines are useful for studies of the complex phenomenon of histamine release.
Inhibition of experimental allergic encephalomyelitis by carrier administered prior to challenge with encephalitogenic peptide‐carrier conjugate
Authors: Rauch Helene C. , Montgomery Ilene Nowicki , Swanborg Robert H.
Published: February 2007

Guinea pigs can be rendered unresponsive to experimental allergic encephalomyelitis (EAE) challenge by prior injections of myelin basic protein (BP) or peptides derived from BP. The synthesized tryptophan‐containing peptide (TrpP, corresponding to residues 114–122) which is the primary encephalitogenic sequence in BP (for guinea pigs) has been conjugated to the non‐central nervous system protein bovine serum albumin (BSA) and used for EAE challenge. It has been shown in this study that prechallenge treatment with the BSA carrier alone can significantly inhibit the induction of EAE by TrpP‐BSA conjugate. That carrier treatment is immunologically specific was determined when prior treatment with cytochrome c did not protect animals from EAE challenge with TrpP conjugated to BSA. In addition, in disease control animals, prechallenge treatment with BP protected guinea pigs against EAE induced with BP or TrpP, and while TrpP did protect guinea pigs challenged with TrpP, it did not protect those challenged with BP. This last finding raises the possibility of a second encephalitogenic sequence in BP or an important role for the carrier in the TrpP conjugate.
Nature of macrophage‐T cell interaction in secondary helper cell generation in vitro Genetic restriction of macrophage‐T cell interaction, which determines T‐B genetic restriction
Authors: Vogt Peter , Erb Peter , Keller Beatrice , Feldmann Marc
Published: February 2007

To investigate the histocompatibility requirements for the macrophage‐T cell interaction in the secondary antibody response, splenic T cells from antigen (carrier)‐primed F1 hybrid mice were restimulated in vitro with carrier‐pulsed F1, parental or allogeneic macrophages. Surviving T cells were cocultured with hapten‐primed F1 or parental “B cells” and restimulated with the appropriate hapten‐carrier conjugate. The IgG antibody‐forming cell response was then measured using a plaque assay.

Mapping of the genetic restriction was performed by use of different strain combinations. T helper cells could be restimulated in the presence of macrophages only provided they shared the I‐A subregion of the major histocompatibility complex with the F1 T cells. T cells from F1 hybrids restimulated with parental or I‐A‐identical macrophages were shown to only cooperate with parental B cells of the same I‐A haplotype as the macrophages used for restimulation. The defect was at the level of the macrophage, as addition of macrophages of the I‐A haplotype used for the restimulation culture reconstituted the ability of F1 helper cells to cooperate with the I‐A‐nonidentical B cells.
Specificity of antigen binding by T cells; competition between soluble and Ia‐associated antigen
Authors: Lonai Peter , Steinman Lawrence , Friedman Varda , Drizlikh George , Puri Joseph
Published: February 2007

Competitive antigen binding experiments were performed with purified T and B cells of C3H.SW (H‐2b) mice. As antigen, (T, G)‐A–L [poly‐L(Tyr, Glu)‐poly‐DL‐Ala–poly‐L Lys] was used, both in an Ia‐containing form, released by adherent cells (IAC, Puri and Lonai, Eur. J. Immunol. 1980.10: 273), and in regular solution. It was found that regular (T, G)‐A–L did not compete with the binding of 125I‐labeled‐IAC‐(T, G)‐A–L even at a 104‐fold excess, whereas IAC‐(T, G)‐A–L inhibited binding at 10‐fold excess. The specificity of (T, G)‐A–L binding to high‐responder T and B cells was compared by using related branched synthetic copolymers as competitors. B cells cross‐reacted with (T, G)‐A–L, (H, G)‐A–L, (Phe, G)‐A–L, (G)‐A–L and (T, G)‐Pro–L. In contrast, antigen‐binding C3H.SW T cells cross‐reacted only with (T, G)‐A–L and (Phe, G)‐A–L, to both of which they are Ir gene‐controlled high responders. Evidence for the Ir gene control of IAC‐binding T cells was obtained by showing that high × low‐responder F1 hybrid T cells preferentially bind IAC‐(T, G)‐A–L processed by processor cells deriving from the high‐responder parental strain. These data are interpreted to suggest that T cells have high affinity for antigen plus self Ia complexes, whereas they have a much lower, if any, affinity for free antigen. It also follows from the results that the structure of the complex ligand may have a role in defining the specificity, H‐2 restriction and Ir gene control of T cells.
Control of idiotope expression by monoclonal anti‐idiotope and idiotope‐bearing antibody
Authors: Kelsoe Garnett , Reth Michael , Rajewsky Klaus
Published: February 2007

Preinjection of C57BL/6 mice with nano‐to microgram amounts of a monoclonal IgG1 antibody directed against a binding site‐related idiotope of the anti‐NP [(4‐hydroxy‐3‐nitro‐phenyl)acetyl] antibody B1‐8 results in enhancement or suppression of the corresponding and of another B1‐8 idiotope in a subsequent anti‐NP response, depending on the dose of the injected anti‐idiotope antibody. The enhancing and suppressive effects appear two weeks after anti‐idiotope administration and are maximal after 6–8 weeks. They are predominantly expressed at the level of IgG, not IgM, antibodies. Enhancement of idiotype expression, i.e. idiotypic memory, can also be induced by the injection of idiotypic antibody of the IgM class, namely antibody B1‐8. This effect might represent one of the general mechanisms by which immunological memory is established.