bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guinea pig immunoglobulin light chain isotypes I. Separation of kappa and lambda chains and the identification of three isotypes of the lambda chain constant homology region
Authors: Brunhouse R. F. , Cebra J. J. 
Published: February 2007

AbstractThe separation of intact kappa chain and two fragments comprising lambda (λ) chain from immunoglobulin light chain pools isolated from strain 13 guinea pigs is achieved by cyanogen bromide digestion and gel filtration before and after reductive cleavage of disulfide bonds. The smaller λ chain fragment derives from the original carboxyl‐terminus of λ chain. The partial sequence of component tryptic and thermolytic peptides of this thirty‐nine residue fragment allowed its complete sequence to be deduced. Three isotypic forms of this λ chain constant region fragment, distinguished by four residue positions showing alternative amino acids, are found expressed by guinea pigs. Each of these three isotypes is more homologous to the other two than to λ chains of any other species. The distribution of amino acid substitutions differentiating these isotypes further supports the view that λ chain isotypes arose in guinea pigs, and in several other species, independently by gene duplication.
Anti‐peroxidase antibody‐secreting hybrid lines. I. Identification, cloning and cell characterization
Authors: Zagury Daniel , Phalente Laurent , Hollande Etienne , Buttin Gérard , Bernard Jacky 
Published: February 2007

AbstractAnti‐peroxidase antibody (Ab)‐secreting hybrids have been produced by fusion of peroxidase (PO)‐immunized mouse lymph node cells and immunoglobulin (Ig)‐secreting P3‐X63‐Ag8 (X63) myeloma cells. Identification of Ab‐secreting hybrids can be performed as early as day 5 after cell fusion by the hemolytic plaque assay. Immediately after identification, hybrids were directly isolated, by means of a micropipette, into Terasaki microchambers containing nutrient medium and a thymocyte filler layer. The yield of secreting hybrids is improved by using this procedure.All the cells of the PO 772 C2 clone show the same ultrastructural pattern and immunocytological properties; they are proplasmocytes, as are the parental X63 cells; they present intracisternae Ab and show no Ig or Fc receptors at the cell surface. Over 90% of viable PO 772 C2 cells form specific plaques. Isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis show that the cells of this clone secrete Ab; the secreted Ig are formed with χ and γ1 chains from the parental X63 cells and specific L and H chains from the lymphoid parent. These biological investigations demonstrate the relative stability of the PO 772 C2 clone secreting anti‐peroxidase antibody.
Cooperation between subclasses of T lymphocytes in the in vitro generation of cytotoxicity against a mutant H‐2K difference An analysis with anti‐Lyt antisera
Authors: Melief Cornells J. , van der Meulen Marian Y. , Christiaans Bernard J. , de Greeve Paul 
Published: February 2007

AbstractThe cellular requirements for the generation of cytotoxicity in mixed lymphocyte reaction (MLR) across an H‐2K mutant difference were analyzed. Treatment of C57BL/6 lymphocytes with either anti‐Lyt‐1 or anti‐Lyt‐2 serum and complement strongly reduced their capacity to mount a cytotoxic response against the B6.C‐H‐2ba mutant. Almost complete reconstitution of the cytotoxic response occurred when a mixture of anti‐Lyt‐1 and anti‐Lyt‐2‐treated cells was allowed to respond. Once cytotoxicity was generated, only anti‐Lyt‐2 serum affected it. It is concluded that in the cytotoxic response to the ba mutant, Lyt‐1 helper cells collaborate with Lyt‐2,3 killer cell precursors in the generation of Lyt‐2,3 killer cells. Lyt‐1,2,3 cells play, if any, a minor role in the generation of cytotoxicity.By comparison, the capacity to generate killer cells in MLR against an H‐2K + IA difference was only affected by anti‐Lyt‐2 and not by anti‐Lyt‐1 serum, indicating that this response is relatively independent of help by Lyt‐1 cells under the conditions tested.
Serologic distinction between the rabbit kappa L chain allotype b4 and an allele b4v
Authors: Smith Linda J. , Sogn John A. , Kindt Thomas J. , Mandy William J. 
Published: February 2007

AbstractRabbit kappa light (L) chain allotypes are controlled by the allelic genes b4, b5, b6, b9 and a recently described allele b4v. The product of the b4v gene differs from that of b4 by at least two amino acid substitutions in the constant region. A serologic distinction between the b4 and b4v allotypes has now been detected by a radioimmune assay using one of six anti‐b4 sera tested. The distinction was enhanced by fractionation of this antiserum on an immunoadsorbent containing cottontail rabbit IgG. IgG with L chains of the b4v type are deficient in their ability to inhibit binding of b4 IgG to the antibody preparation. L chains isolated from b4 and b4v IgG samples could not be distinguished by this assay indicating that interaction with an H chain is required for expression of the L chain determinants that differentiate b4 from b4v.
Identification of β adrenoceptors during thymocyte ontogeny in mice
Authors: Singh Upendra , Millson David S. , Owen John J. T. , Smith Pamela A. 
Published: February 2007

AbstractThymocytes have been studied at various stages during ontogeny in relation to their responsiveness to β adrenoceptor agonists and ability to bind L‐[propyl‐2,3‐3H]dihy‐droalprenolol ([3H]DHA), a specific radioligand of the β adrenoceptor. Specific [3H]DHA binding and the activity of an isoproterenol‐sensitive adenylate cyclase were compared and correlated between (14 to 20‐day) fetal mouse thymocytes and young adult thymocytes. Preliminary experiments show that [3H]DHA binding to thymocytes demonstrated the kinetics, affinity and stereospecificity expected of binding to adenylate cyclase‐coupled β adrenoceptors. Similarly, isoproterenol was shown to selectively increase intracellular adenosine 3′: 5′‐cyclic monophosphate (cAMP) levels and was antagonized by propranolol (a β adrenoceptor antagonist), but not by phentolamine (an a adrenoceptor antagonist), nor by lignocaine (a local anesthetic). The rises in fetal thymocyte cAMP levels found after stimulation with isoproterenol were of greater magnitude than in adult thymocytes. The number of [3H] DHA‐binding sites in both fetal and adult thymocytes was the same (Bmax = 50 fmol/2 × 106 cells). However, the affinity of the binding sites for [3H] DHA was less for the adult cells than the fetal cells (with KD values of 8.0 and 2.2 nM, respectively); this was reflected in the amount of [3H] DHA bound being up to 8 times greater in the embryonic cells.
Exclusion of VHa and VHy loci expression on individual B cells from normal and YH allotype‐suppressed rabbits
Authors: Knight Katherine L. , Schweizer Marianne , Pernis Benvenuto 
Published: February 2007

AbstractThe distribution of two heavy chain subgroups, VHa and VHy, on rabbit peripheral blood lymphocytes was examined by double membrane immunofluorescence. Fluorescent anti‐a 1 and anti‐y 33 were found to react with separate B cell populations; no doubly stained cells were observed. Further evidence for the independent expression of genes controlling the VHa and VHy subgroups was obtained by neonatal suppression of a 2 or y 33 in a2y33/a3y− heterozygous rabbits. Suppression of VHa did not affect the expression of VHy, nor did the suppression of VHy affect the expression of VHa. The expression of a single VH gene per B cell is in marked contrast to the simultaneous expression of multiple CH genes.
Maturation of B lymphocytes. II. Sequential appearance of increasing IgM and IgD in the adult bone marrow
Authors: Lala Peeyush K. , Layton Judith E. , Nossal Gustav J. V. 
Published: February 2007

AbstractThe relationship between surface IgM (sIgM) and surface IgD (sIgD) was examined on small lymphocytes in the adult murine bone marrow or prepubertal spleen. Cells were sorted on the basis of different sIgM levels by a fluorescence‐activated cell sorter (FACS) and relabeled for sIgD or total sIg by a sandwich technique using 125I‐labeled protein A and radioautography. For detecting sIgD, an anti‐δ allotype reagent was used in congenic mice. Cells lacking sIgM in the bone marrow or spleen were also found to be sIgD−; thus, sIgD appeared only in the presence of sIgM. Weak sIgM‐bearing cells in the bone marrow also had no sIgD indicating that sIgD appeared only after the acquisition of a significant level of sIgM. Subsequently, the incidence of sIgD+ cells increased in fractions showing increasing sIgM levels indicating the acquisition of new sIgD by “sIgM only” cells with increasing maturation levels in the bone marrow. In marrow lymphoid cells expressing both Ig isotypes, sIgM and sIgD levels increased in parallel, possibly with increasing maturation level. In the spleen, the incidence of sIgD+ cells among various cell fractions showing different sIgM levels was found constant. However, spleen cells bearing both receptors, showed a small increase in the sIgD level with increasing sIgM level.
Antibody‐independent activation of complement by human peripheral B lymphocytes
Authors: Gutiérrez Carmen , Vega Jesus , Kreisler Miguel 
Published: February 2007

AbstractNormal human peripheral blood lymphocytes were shown to activate complement in normal human serum (NHS). This activation led to C3 fixation on the cell membrane, which in turn was visualized by fluorescence. The reaction occurred in the absence of detectable amounts of antibodies, since an agammaglobulinemic patient's serum also supported complement activation, and the results were unaltered by absorption of normal human serum. Trypsin treatment of lymphocytes to remove possible complement activators bound to the cell membrane, did not have any effect on the complement activation by lymphocytes. Complement membrane fluorescence was abolished in the presence of EDTA or ethyleneglycolbis(aminoethylether) tetraacetate (EGTA) supplemented by Mg++ions indicating that the classical pathway of complement activation was involved in the reaction. Experiments performed with T and B‐purifiedpopulations showed that the phenomenon was confined to the B cell fraction. Complement deposition did not diminish the number of EAC rosettes, and viability remained unchanged after exposure of lymphocytes to normal human serum.
Peanut agglutinin. II. Characterization of the Thy‐1, Tla and Ig phenotype of peanut agglutinin‐positive cells in adult, embryonic and nude mice using double immunofluorescence
Authors: Roelants Georges E. , Mayor‐Withey Kathleen S. , London Jacqueline , Serrano Beatrice 
Published: February 2007

AbstractThe Thy‐1, Tla and Ig phenotype of peanut agglutinin (PNA)‐binding cells was characterized in various strains of mice. In the thymus, PNA was found to bind principally but not exclusively to the Thy‐1+ Tla+ Ig− steroid‐sensitive cortical thymocytes. Thy‐1+ Tla− Tg− steroid‐resistant cells are not labeled with PNA. In other lymphoid organs, PNA bound to a minority of T or null cells but generally not to B cells.During ontogeny, PNA+ and PNA− T lineage cells appear simultaneously in the liver at day 10 of gestation, in the thymus at day 11 and in the spleen at day 18. No evidence was found for a maturation from PNA+ to PNA− cells. Prethymocytes present in nude mice were also divided into a PNA+ and PNA− population.The findings possibly support the proposition that cortical and medullary thymocytes develop independently. Moreover, they suggest that both populations might arise from distinct precursors and give rise to distinct functional peripheral T cells.
Clonal dominance of low‐affinity antibodies in rabbit hyperimmune anti‐streptococcal group A‐variant polysaccharide antisera
Authors: Schaich Wolfgang , Wright J. Keith , Rodkey L. Scott , Braun Dietmar G. 
Published: February 2007

AbstractIntraveneous hyperimmunization of selectively bred rabbits with streptococcal group A‐variant vaccines elicits antibody responses of restricted heterogeneity at high antibody levels. In these antisera, IgG with dissociation constants KD = 10−6 M constitutes 90% and IgG with KD = 10−9 M accounts for only 10% of the group A‐variant polysaccharide‐specific antibodies. The low affinity antibody fraction represents the dominant clonotypes. Preparative isoelectric focusing in granulated (Ultrodex G‐75) gels was used to successfully purify single‐band material belonging to dominant spectrotypes. Affinity studies with these antibody fractions with the highest reported degree of purity yielded KD = 10−6 M values, thus confirming that clonal dominance is exclusively associated with low‐affinity antibodies. Since it is known from previous work (M. Cramer and D. G. Braun, Scand. J. Immunol. 1975. 4: 63) and from the rabbit antisera used here that clonal dominance of this sort is long‐lived, this work fails to support the argument of immune maturation. The data more logically relate to antibodies that emerge with different subspecificities ‐ recognized in the antigen as a function of time in immunization procedures — rather than to an inherent property of the immune system.
High nonspecific reactivity of normal lymphocytes against rnycoplasma‐infected target cells in cytotoxicity assays
Authors: Brooks C. G. , Rees R. C. , Leachn R. H. 
Published: February 2007

AbstractSeveral rat tumor cell cultures were deliberately infected with three species of mycoplasma commonly found as contaminants of cell lines grown in vitro, and the effect of mycoplasma infection on the results of cytotoxicity assays was examined. Lymph node cells and spleen cells from normal animals showed an apparently high spontaneous cytotoxic activity against tumor cells infected with either M. arginini or M. hyorhinis, but the reactivity against cells infected with M. orale was not significantly higher than that against uninfected cells. The high reactivity towards tumor cells infected with M. arginini and M. hyorhinis bore a close resemblance to natural cell‐ mediated immunity in that spleen cells were much more reactive than lymph node cells, spleen cells from nude mice were as effective as spleen cells from normal mice, and the reaction crossed both strain and species barriers. However, closer examination revealed that the cytotoxic effects were directly caused by depletion of arginine or other essential nutrients from the medium. These findings imply that a cautious approach should be taken when interpreting certain aspects of spontaneous cell‐mediated cytotoxicity, and that the greatest care be taken to ensure that the cells used as targets in any cytotoxicity test are mycoplasma‐free.
Normal immunosuppressive protein inhibition of human and murine lymphoblastoid cell line proliferation
Authors: Nelken David , Ovadia Haim , Hanna Nabil 
Published: February 2007

AbstractNormal immunosuppressive protein, prepared from human plasma by DEAE‐cellulose chromatography, inhibits DNA synthesis in human cell lines of lymphocytes of both T and B origin. It also inhibits [3H]thymidine incorporation in mouse cell lines. Normal immunosuppressive protein was able to inhibit the proliferation of these cells, although they were already transformed and had a high rate of DNA synthesis. On the other hand, it does not inhibit myeloid cells or fibroblasts.
Immune depression in trypanosome‐infected mice. II. Characterization of the spleen cell types involved
Authors: Roelants Georges E. , Pearson Terry W. , Mayor‐Withey Kathleen S. , Lundin Lena B. , Tyrer Harry W. 
Published: February 2007

AbstractSpleen cells from Trypanosoma congolense‐infected mice showed a drastic depression in their capacity to respond to B and T lymphocyte mitogens and to allogeneic spleen cells in mixed lymphocyte cultures. Spleen cells from infected mice were also poor stimulators in mixed lymphocyte cultures. The poor responsiveness or stimulation capacity was not due simply to dilution of relevant B or T lymphocytes by the large number of null cells found in the spleens of infected animals. These null cells expressed approximately eight times more H‐2 antigen than spleen cells from normal (uninfected) mice and were devoid of Ia antigens.
Antigen‐specific suppressor cells in hapten‐specific carrier‐determined tolerance
Authors: Aldo‐Benson Marlene A. 
Published: February 2007

AbstractTolerance to the hapten 2,4‐dinitrophenyl (DNP) induced by the injection of DNP coupled to isologous IgG (carrier‐determined tolerance) is associated with a receptor blockade of antigen‐binding lymphocytes. In the present study, hapten‐specific suppressor cells were detected in the spleens of mice made tolerant by intravenous injection of 200 μg DNP‐IgG. When spleen cells from mice rendered tolerant to DNP were co‐cultured with normal spleen cells in Marbrook cultures, the response to DNP‐Ficoll was suppressed, while the response to sheep red blood cells was not altered. Depletion of T cells from these spleens restored the normal anti‐DNP response. The suppressor cells were not detectable in the spleen lymphocyte population of mice in the early stages of tolerance but were present on day 7 after injection of tolerogen, and disappeared by day 14. Mice injected with larger doses of 1 mg or four weekly doses of 200 μg DNP‐IgG did not have detectable suppressor cells. Thus, it appears that a short‐lived suppressor T cell is generated in carrier‐determined tolerance. This cell most likely plays a minor role in the mechanism of carrier‐determined tolerance and may be associated with the receptor blockade which is seen early in tolerance.
A novel interaction involving a polypeptide chain (P33) in covalent linkage with IgM on the surface of a Burkitt lymphoma cell line (Daudi)
Authors: Singer Paul A. , Williamson Alan R. 
Published: February 2007

AbstractThe surface IgM of Daudi Burkitt lymphoma cells has been shown to consist of μ chains and x chains covalently linked, by disulfide bonding, to a novel polypeptide chain of approximate molecular weight 33 000. This novel polypeptide chain (P33) is similar in several properties to the heavy chain of the Ia antigen: glycoprotein nature; apparent molecular weight; isoelectric behavior and cysteine content. The linkage of P33 to surface immunoglobulin has not been observed with any other human lymphoma or lymphoblastoid cell lines.
Adrenoreceptors, cyclic nucleotides, and the regulation of spleen cell antigen binding in urodele and anuran amphibians
Authors: Hodgson Ruth M. , Clothier Richard H. , Balls Michael 
Published: February 2007

AbstractAdults of four anuran amphibian species and five urodele species were immunized with a 25% suspension of horse erythrocytes. After 8 or 14 days, spleen lymphocytes were removed and their specific red cell‐binding capacities tested by immunocytoadherence. Antigen‐binding cells were classified as high‐dose nonsecretory or secretory according to whether they bound a single layer or several layers of erythrocytes. Adrenaline stimulated α and β adrenoreceptors of cells from all four anuran species, giving an α effect (a reduction in rosette formation) in the presence of β antagonists, and a β effect (an increase) in the presence of α antagonists.Responses similar to α and β adrenergic responses were shown by samples treated with dibutyryl cyclic GMP (db‐cGMP) and dibutyryl cyclic AMP (db‐cAMP), respectively, and added methylxanthines and ionophores also increased rosette formation by Xenopus laevis lymphocytes. Added alone, the antagonists used did not affect rosette formation, and the increase induced by db‐cAMP was not blocked by a β adrenoreceptor antagonist.The stimulation of a and/or β adrenoreceptors resulted in a reduction in rosette formation by cells from all five urodele species, as did the addition of db‐cGMP. However, in samples from four urodele species, db‐cAMP increased rosette formation. Added db‐cAMP reduced rosette formation by lymphocytes from the fifth urodele species tested, i.e. Triturus cristatus carnifex. The results are discussed in terms of the involvement of surface adrenoreceptors and intracellular mechanisms in the regulation of immune responses, and in terms of the evolution of immune capacity within the Amphibia.
Requirement of parental T lymphocytes for the in vitro induction of F1 hybrid anti‐parent cytotoxicity
Authors: Nakamura Ichiro , Cudkowicz Gustavo 
Published: February 2007

AbstractPrimary F1 anti‐parent cell‐mediated lympholysis (CML) is a specific response generated in mixed cultures by F1 T lymphocytes with the aid of macrophage‐like cells of responder and stimulator type. A model was described in which the induction of this response required T lymphocytes among stimulators, as judged by the lack of induction following T cell depletion of parental cells by (a) separation on nylon wool columns, (b) treatment with anti‐Thy‐1 antiserum and complement, (c) treatment of donor mice with rabbit anti‐mouse thymocyte serum, or (d) congenital absence of the thymus in nu/nu donors. The parental T lymphocytes required were relatively mature, as indicated by resistance to cortisone, persistence after adult thymectomy, and sensitivity to xenogeneic anti‐thymocyte antiserum. T‐deprived cell populations retained the ability to induce allogeneic CML.Parental lymphoma cells, spleen cells stimulated by mitogens for T or B lymphocytes, normal cells of central and peripheral lymphoid organs, and peritoneal exudate cells, all served to a varying extent as targets for anti‐parent cytotoxic effectors (CTL), but there was no close correlation with their ability to serve as stimulators. Spleen or peritoneal exudate cells of athymic mice were capable of serving as “antigenic” targets for specific F1 anti‐parent CTL, and yet failed to induced the response. Thus, the role of parental T cells in the induction of F1 anti‐parent cytotoxicity was not that of bearing the “antigen”. It was concluded that irradiated parental T lymphocytes provided back stimulation to F1 hybrid responders, either directly or indirectly via the activation of macrophage‐like cells. Under certain circumstances, however, the requirement for parental T cells can be circumvented.
Close association between particular I region‐determined cell surface antigens and Ir gene‐controlled immune responsiveness to synthetic polypeptides in wild rats
Authors: Günther Eberhard 
Published: February 2007

AbstractThe relationship between major histocompatibility complex (MHC) and genetic control of immune responsiveness to the synthetic polypeptides (T, G)‐A–L [poly‐(LTyr,LGlu)‐poly(DLAla)–poly(LLys)] and (H, G)‐A–L [poly(LHis,LGlu)‐poly‐(DLAla)–poly(LLys)] has been studied in 26 wild rats. The major histocompatibility complex (MHC) genotype frequencies observed were not different from those expected according to the Hardy‐Weinberg formula. More than half of the wild rats carried MHC‐linked responder Ir‐TGAL and Ir‐HGAL genes. High or intermediate responsiveness to (T, G)‐A–L and high responsiveness to (H, G)‐A–L were always found to be associated with particular I region‐determined cell surface antigens. These antigens could be identified serologically and by primary and secondary mixed lymphocyte reactions, and were similar or identical to I region products of (T, G)‐A–L high responder or (H, G)‐A–L intermediate responder inbred rat strains. The strong associations between cell surface antigens and immune responsiveness could be due to linkage disequilibrium or to pleiotropy. Since the same I region‐determined cell surface structure could be associated either with high or intermediate anti‐(T, G)‐A–L antibody titers, the presence of the Ia antigen(s) identified did not seem to guarantee high antibody responsiveness to the test antigen.