bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular characterization of a nonsecreting myeloma mutant
Authors: Argon Yair , Burrone Oscar R. , Milstein César 
Published: February 2007

AbstractThe nonsecreting myeloma mutant, NSII/1, derived from MOPC 21 a mouse myeloma cell line, does not produce L chains and expresses a smaller than normal γ1 heavy chain, H* (Cowan, Secher and Milstein, J. Mol. Biol. 1974. 90: 691). The free H* is not secreted, but secretion can be rescued in hybrids expressing a light chain. By sequencing L and H chain‐cloned cDNA derived from NSII/1 we find only one light chain mRNA expressed which belongs to an aberrantly rearranged kappa gene. We also find that the H* heavy chain is the result of a point mutation. H* mRNA contains an A instead of the G found in wild type at position 1125. The corresponding tryptophan 406 becomes a chain termination, giving rise to a 67 amino acid deletion at the C‐terminus. The H* is core‐glycosylated, but its state of assembly is abnormal: H* forms high molecular weight, S–S‐bonded complexes. The results are discussed with reference to the putative toxic properties of free heavy chains and the failure of some chains to be secreted.
Inhibition of glycosylation prevents H‐2K and D antigen expression on SV40 virus‐transformed cells
Authors: Swaminathan Sankar , Gooding Linda R. 
Published: February 2007

AbstractTunicamycin, an inhibitor of glycosylation, was used to examine the role of carbohydrate moieties of glycoproteins involved in recognition of Simian virus 40 (SV40)‐transformed cells by cytotoxic T lymphocytes (CTL). Tunicamycin treatment renders such cells refractory to lysis by H‐2 restricted, SV40‐specific CTL as well as by allogeneic CTL directed only against H‐2 antigens. Treated cells are no longer susceptible to lysis by anti‐H‐2 antisera and complement, nor are they stained by monoclonal anti‐H‐2 antibodies in an indirect immunofluorescence assay. No accumulation of H‐2 proteins was detected in immunoprecipitates from cells labeled with [35S]methionine in the presence of tunicamycin. It is concluded that tunicamycin prevents the expression of H‐2 glycoproteins in these cells, perhaps due to accelerated degradation of the unglycosylated molecules.
Are “natural killer” cells involved in allograft rejection?
Authors: Nemlander Arto , Saksela Eero , Häyry Pekka 
Published: February 2007

Abstract“Natural killer” (NK) effector cells and large granular lymphocytes (LGL) are found inside rat renal allografts during rejection. Their appearance in situ precedes the appearance of cytotoxic T lymphocytes, and concomitantly with their influx in the allograft, the NK activity and the LGL are depleted from the recipient spleen. This suggests that the NK effector cells and the LGL are involved in allograft rejection, although their role(s) among the other in situ inflammatory effector pathways remains to be clarified.
Antigenic markers of V domain of mouse MOPC 21 IgG1 L chain. The conformational basis of VL domain markers and content of MOPC 21 VL‐like immunoglobulins in sera of inbred mouse strains
Authors: Rokhlin Oscar V. , Petrosyan Margarita N. , Ibraghimov Alexander R. , Vengerova Tamara I. , Bogachova Galina T. 
Published: February 2007

AbstractAntisera were raised in rabbits against L chains, isolated from mouse myeloma protein MOPC21 (γ1,x, Vx15 group). Specific antibodies for the V and C domain of MOPC 21 L chain were obtained by cross‐immunoadsorption of the antisera. The pure anti‐V and anti‐C antibodies were fixed on diazocellulose and used as immunosorbents. The inhibitory capacity of L chain‐monomers and dimers isolated from the L chain preparation was compared to that of intact IgG1 using binding inhibition of 125I‐labeled IgG1 on the antibody‐containing immunosorbents. It was established that changes of IgG1 quaternary structure influences the conformational state of the L chain V domain only. The inhibitory capacity of the V domain is 1000‐fold lower in L monomers, if compared with native IgG1, and only 10‐fold lower than in L dimers. The inhibiting capacity of the C domain, however, does not differ in L monomers and intact IgG1. Thus the conformational rigidity of the C domain co‐exists with conformational flexibility of the V domain on the same polypeptide chain. We tried to estimate the content of MOPC 21 VL‐like normal IgG in mouse serum of 6 inbred strains using antibodies against the VL domain. Data obtained by inhibition of radioimmunoadsorption, indicate that in C57BL/6 mice 0.08% of normal serum Ig carries a VL region which is idiotypically related to the VL of MOPC 21. In serum Ig of BALB/c mice the percentage is 0.16.
T cell‐mediated cytolysis: on the strength of effectortarget cell interaction
Authors: Bongrand Pierre , Pierres Michel , Golstein Pierre 
Published: February 2007

AbstractAllosensitized lymphoid cell populations contain T lymphocytes that can bind to target cells and lyse them. We asked whether there was a relationship between lymphocyte target cell‐binding strength and occurrence of cytolysis. Using graded shear forces to dissociate effector‐target cell conjugates, we found that (a) within an allosensitized lymphoid cell population derived from an heterogeneous mixed leukocyte culture, there were lymphocyte‐target cell conjugates with binding strengths differing by a factor of at least 102, (b) even the minimal force required to release a significant amount of bound target cells could disrupt the plasma membranes of some tumor cells and (c) these tumor cells disrupted by shear forces were probably part of cytolysis‐conducive rather than of non‐cytolysis‐conducive conjugates.We combined this approach with the use of cytolysis‐inhibiting monoclonal antibodies (mAb), and found that antibody‐induced decrease of cytolysis was correlated with a decrease in the percentage of strong or total conjugates, depending on the mAb used. When lectins were added to overcome the inhibitory effect of the mAb, reappearance of cytolytic activity correlated with reappearance of conjugates. This was especially striking using wheat germ agglutinin (WGA): the addition of WGA to irrelevant effector‐target cell combinations did not lead to cytolysis; however, the addition of WGA to relevant effector‐target cell combinations inhibited by mAb led to reappearance of cytolysis and of strong conjugates. Taken together, these and other results suggested that under our experimental conditions a threshold level of binding strength between effector and target cells might be important, although not sufficient, for T cell‐mediated cytotoxicity. These results were not inconsistent with the involvement of mechanical factors in this process. Also, they were in line with the concept of nonantigen‐specific lymphoid cell surface interacting molecules, detected by the mAb used and important for the establishment of strong, functional lymphocyte target cell interactions. Finally, they underlined the necessity of a quantitative estimate of cell‐cell binding strength when investigating the effect of a given agent (e.g. a mAb) on lymphocyte target cell recognition.
Committed precursors of B and T lymphocytes in chick embryo bursa of Fabricius, thymus, and bone marrow
Authors: Brand Ann , Galton Jane , Gilmour Douglas G. 
Published: February 2007

AbstractLymphocyte precursors in bursa of Fabricius, thymus and bone marrow (BM) of chick embryos were studied at different stages of incubation over 12–21 days, and for their state of commitment to B or T cell lines of development. Cell suspensions were fractionated on albumin gradients to remove nonlymphoid cells and incubated in vitro with bursopoietin, a specific inducer of B cells, or crude chicken thymus extract, a specific inducer of T cells, or ubiquitin, a nonspecific inducer. Precursors were identified by increases in numbers of cells bearing surface alloantigens as determined by immunofluorescence, either Bu‐1 (specific to B cells) or Th‐1 (specific to T cells). Precursors inducible to Bu‐1+ cells were found in bursal cells and BM cells from all age groups but not in thymic cells. Precursors inducible to Th‐1+ cells were found in thymic preparations and BM cells at all ages, but in significant numbers in bursa on day 12 only. Because B and T precursors were never found together in bursa or thymus, or only in very unequal amounts, it was concluded that precursors in these organs were not multipotential but were separately committed to one or other line of development. This argument did not apply to BM cells, for which other evidence was obtained. Bu‐1+ cells were specifically induced in BM cells with bursopoietin and then removed by complement‐dependent cytolysis with anti‐Bu‐1 antiserum. When the remaining cells were incubated with ubiquitin, only Th‐1+ cells were induced, showing that Bu‐1 and Th‐1 precursors were separately committed. Surface IgM was never induced on either bursal or BM lymphocytes. The Ia (or B‐L) antigen was inducible on 12‐ to 21‐day bursal cells, but could not be generated on BM cells until day 14 onwards. The pattern of occurrence of committed lymphocyte precursors in the developing chick embryo suggests that these cells are released into the circulation from both central lymphoid organs at their respective times of high lymphopoietic activity, and accumulate in the BM at least up to the time of hatching. Moreover, the presence of committed B precursors in bursa and committed T precursors in thymus at times and in quantities appropriate to the known features of avian lymphopoiesis leads us to conclude that in vitro induction is analogous to a true stage of in vivo B and T cell differentiation.
A monoclonal antibody (100C5) to the Lyt‐2− T cell population expanding in MRL/Mp‐lpr/lpr mice detects a surface antigen normally expressed on Lyt‐2+ cells and B cells
Authors: Dumont Francis J. , Habbersett Robert C. , Nichols Elizabeth A. , Treffinger Jacqueline A. , Tung Amar S. 
Published: February 2007

AbstractMRL/Mp‐lpr/lpr (MRL‐lpr) mice develop a generalized lymphadenopathy reflecting the expansion of a Lyt‐2− T cell population. The present report describes the pattern of reactivity of a xenogeneic monoclonal antibody (mAb 100C5) directed against this T cell population. By single‐ and two‐color flow cytofluorometry analysis this mAb was found to stain brightly 80–90% of T cells in enlarged MRL‐lpr lymph nodes. In contrast lymph node T cells from congenic MRL‐MP‐+/+ (MRL‐+) mice were either unstained (70%) or weakly stained (30%), these latter cells being mostly Lyt‐2+. Unexpectedly, all lymph node B cells from MRL‐+ or MRL‐lpr mice were as strongly 100C5+ as MRL‐lpr T cells. Similar observations were made in C57BL/6‐lpr/lpr and C57BL/6‐+/+ mice. Molecular weight determination suggested that the 100C5 mAb binds to the same molecule (Mr = 220000) on MRL‐lpr T cells and normal B cells.
Anti‐idiotypes against anti‐H−2 antibodies VI. Detection of shared idiotypes among monoclonal anti‐H−2 antibodies
Authors: Bluestone Jeffrey A. , Auchincloss Hugh , Sachs David H. , Fibi Matthias , Hämmerling Günter J. 
Published: February 2007

AbstractAnti‐idiotypes produced against monoclonal anti‐H‐2 antibodies have been used to examine idiotope sharing among a panel of anti‐major histocompatibility complex (MHC) antibodies detecting the same and different specificities. Both xenogeneic anti‐100‐30 and anti‐3‐83, which did not react with predominant idiotypes in conventional alloantisera, detected shared idiotopes on 3‐83 and 100‐30 as well as on 2 other monoclonal anti‐H‐2Kk antibodies. All 4 monoclonal antibodies recognized the same epitope cluster on the Kk molecule and detected the same serological specificity, H‐2.5. In contrast, syngeneic and allogeneic anti‐idiotype produced against the same monoclonal antibodies did not detect these cross‐reactive determinants. In several instances, xenogeneic anti‐idiotype reacted with anti‐MHC antibodies which recognized distinct H‐2 determinants, suggesting that anti‐MHC antibodies detecting the same or different specificities may share idiotypic determinants. These reagents may be useful probes of the anti‐MHC immune repertoire.
Two monoclonal antibodies identifying a subset of human peripheral mononuclear cells with natural killer cell activity
Authors: Bai Yan , Beverley Peter C. L. , Knowles Robert W. , Bodmer Walter F. 
Published: February 2007

AbstractTwo monoclonal antibodies (H25 and H366) raised against the cultured T lymphoid cell line HSB‐2 were shown to define a subset of peripheral mononuclear cells with natural killer and killer cell activity. The two antibodies show similar tissue distributions. Radioimmune trace binding assay shows that H25 and H366 react with all T cell lines tested and with the monocyte line U937, but weakly or not at all with cell lines of B, myeloid or erythroid origin. Both antibodies react with about 10% of E rosetteforming cells and a proportion of nonrosetting lymphocytes and monocytes. They do not react with B lymphocytes, granulocytes, red cells or platelets. A proportion of thymocytes and low numbers of tonsil and spleen mononuclear cells are positive. H25+ and H366+ lymphocytes are medium‐sized cells with abundant granular cytoplasm, and most carry Fc receptors for IgG. H25 and H366 immunoprecipitate two polypeptide chains of 96 and 53kDa from surface‐labeled HSB‐2 cells.
Monoclonal anti‐VH antibodies recognize a common VH determinant expressed on immunoglobulin heavy chains from various species
Authors: Eshhar Zelig , Gigi Orit , Givol David , Ben‐Neriah Yinon 
Published: February 2007

AbstractOur previous work using rabbit antibodies to the variable region of MOPC315 myeloma heavy chain (VH) has indicated the existence of framework determinant(s) common to many murine heavy chains. Here we report the characterization of anti‐VH monoclonal antibodies (mAb) prepared in an attempt to elucidate the nature of the common VH determinant. We immunized AKR/J mice with a purified VH315 fragment and generated somatic cell hybrids by the fusion of the immune AKR/J splenocytes with the NS1 myeloma cells. Thirty‐seven common anti‐VH and 57 subgroup VHI‐specific hybridomas have been established and characterized. Whereas the anti‐subgroup mAb seemed to react with a determinant unique to the MOPC315 (mouse VHI) subgroup, all the anti‐VH mAb reacted with myeloma heavy chains of different VH subgroups, class and allotypes. Antibody competition studies revealed that the VH subgroup determinants are distinct from the common VH determinants and that both were also recognized by the rabbit polyclonal antibodies. The common VH determinants were found to be “hidden” determinants on intact immunoglobulin molecules being exposed only on isolated heavy chains. Furthermore, they are sequential determinants since they are preserved on fully denatured heavy chains. The common VH determinants are shared by immunoglobulins of a wide range of vertebrates from amphibia to man and thus represent antigenic structures which were highly conserved throughout evolution.
Characterization of chicken T cell growth factor
Authors: Schnetzler Marianne , Oommen Anna , Nowak Jerzy S. , Franklin Richard M. 
Published: February 2007

AbstractChicken spleen and peripheral blood lymphocytes were tested for their ability to produce T cell growth factor (interleukin 2, IL2) upon stimulation with phytohemagglutinin or concanavalin A (Con A). Using a qualitative microassay, peak activity was found in 24‐h supernatants of mitogen‐stimulated lymphocytes. These supernatants permitted continuous growth of chicken lymphocytes for several weeks and increased the Con A response of chicken thymocytes. A quantitative probit microassay was developed and used in the further studies when appropriate. Chicken IL2 binds specifically to thymocytes and activated T cells and its action upon T blast cells cannot be blocked by cyclosporin A. The molecular weights of the two biological active peaks found by gel filtration of the native IL 2 preparation were in the range 19500‐21500 and 9000‐11500. A single polypeptide of molecular weight 13000 was found by gel electrophoresis under reducing conditions.
Immunoglobulin heavy chain class switch from IgM to IgG in a hybridoma
Authors: Thammana Pallaiah , Scharff Matthew D. 
Published: February 2007

AbstractA subclone of an IgM‐producing hybridoma has been identified which has switched to producing an IgG1 antibody. The parent hybridoma, PC‐140, produces an antibody which binds phosphorylcholine and reacts with monoclonal antibodies that recognize myelomas of the T‐15 idiotype. The IgG1 antibody binds phosphorylcholine with the same affinity as the parental IgM and also reacts with the anti‐T‐15 monoclonal antibodies. While the IgM‐producing parent hybridoma does not express detectable surface IgM, the IgG1‐producing subclone produces both membrane and secreted IgG1.
The mechanism of synergistic complement‐mediated lysis of rat red cells by monoclonal IgG antibodies
Authors: Hughes‐Jones Nevin C. , Gorick Barbara D. , Howard Jonathan C. 
Published: February 2007

AbstractThe mechanism of synergistic complement‐mediated lysis of rat red cells was investigated using rat monoclonal antibodies against class IR1Aa antigens. The increased lytic activity when using two antibodies simultaneously is due to the increase in the number of activated C1 molecules on the cell surface and this results from (a) an increase in the number of binding sites for C1q, (b) an increase in the functional affinity constant for C1q binding and (c) an increase in the rate of activation of C1. Complete lysis of red cells was only achieved if one member of the synergistic pair was of the γ2b isotype, and this isotype weas the only one to which binding of 125I‐labeled C1q could be detected. A partial synergistic effect was seen using an F(ab′)2 fragment of antibody. Increased uptake and activation of C1 probably results both from the presence of two antibodies attached to each antigen molecule and from the formation of antigen‐antibody catenars.
Biological and biochemical characterization of an interleukin 1‐like factor from rat C6 glioma cells
Authors: Fontana Adriano , McAdam Keith P. W. J. , Kristensen Flemming , Weber Elisabeth 
Published: February 2007

AbstractIt has been previously reported that lipopolysaccharide‐stimulated murine astrocytes produce a factor which enhances the proliferative response of thymocytes to lectins. The present report demonstrates that a rat astrocytoma cell (C6 cells)‐derived factor appears to be similar to macrophage‐derived interleukin 1 (IL1) in its biological activities and biochemical characteristics. Upon injection into mice, supernatants of C6 cells induce the production of serum amyloid A. The C6 cell‐derived factors enhance the response of thymocytes to phytohemagglutinin and the growth of fibroblasts whereas no effect on the growth of neuroblasts and of a strictly interleukin 2 (IL2)‐dependent T cell line was observed. On an AcA 54 column the C6‐derived factors acting on thymocytes and fibroblasts coeluted as a single peak of Mr> = 13500 to 18000; the semipurified factor was found to enhance the lymphocytes' production of IL2. These observations demonstrate that cells not belonging to the mononuclear phagocyte lineage are able to produce factors identical or closely related to IL1.
The analysis of an anti‐fluorescein cytotoxic response
Authors: Christensen Neil , Skinner Margot , Marbrook John 
Published: February 2007

AbstractThe detailed kinetics of the appearance of clones of anti‐fluorescein cytotoxic T lymphocytes (CTL) in a primary limiting dilution response have been examined. The addition of factors from the supernatants of concanavalin A‐stimulated rat spleen cell cultures was necessary to obtain linear dose‐response curves and strong primary responses. In a standard primary response the maximum detectable number of specific clones was found, on day 5, to be derived from precursors having a frequency of 1 in 10000 spleen cells. When limiting dilution cultures were restimulated on day 3, responses on day 5 were unaffected but new clones appeared on day 7 with a frequency of 1 in 1000. The emergence of the day‐7 response depends on the addition of factor(s) on day 3. It is proposed that the early low frequency precursors detected on day 5 and the high frequency precursors detected on days 7–9 are derived from two stages in the differentiation lineage of CTL precursors. Restimulation of limiting dilution cultures involves not only the continued clonal expansion of primary responses but also the emergence of new “clones” of specific CTL.
Diversity in the biological properties of anti‐influenza cytotoxic T cell clones
Authors: Taylor Patricia M. , Askonas Brigitte A. 
Published: February 2007

AbstractThis study reports the examination of in vivo and in vitro properties of an antigendependent murine cytotoxic T cell (Tc) clone T5/5 specific for type A influenza virus. This clone differs morphologically and in its migratory pattern and biological properties from a previously examined anti‐influenza Tc clone L4 which grew in T cell growth factor independently of antigen. Unlike Tc clone L4, T5/5 cells do not release significant amounts of immune interferon on contact with influenza‐infected target cells nor do they limit virus replication in vivo, although they efficiently lyse influenza‐infected target cells and can release interferon in the presence of concanavalin A. Thus individual Tc clones vary in function and further work is required to establish the properties of Tc that are associated with host protection against virus infection.
Idiotypic and fine specificity analysis of a (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)‐specific suppressor T cell hybridoma at the level of cell surface structures, isolated receptor material and functional suppressor factor
Authors: Suzuki Gen , Cramer Matthias , Hayakawa Kyoko , Okumura Ko , Tada Tomio 
Published: February 2007

AbstractThe (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)‐specific T suppressor cell hybridoma 7C3‐13 was established by fusing splenic B10.BR T cells enriched on NP‐coated petri dishes with the AKR thymoma BW5147. 7C3‐13 was selected by anti‐NPb idiotypic and anti‐I‐Jk antibodies in microcytotoxicity tests. The hybridoma expressed H‐2k, I‐Jk, Qa‐1, Thy‐1.1 as well as idiotypic (binding site‐related) and framework Ig VH determinants, while it was negative for I‐A, I‐E/C, Thy‐1.2, Lyt‐1, Lyt‐2 and Ig constant region determinants. Hapten‐binding receptor material could be isolated from 7C3‐13 cells on NP‐coupled nylon nets and functionally active T suppressor factor (TsF) could be extracted from the hybridoma. Both types of soluble molecules express NPb idiotype, but the TsF carries I‐J determinants in addition while the isolated receptors do not. The molecular weight of the isolated receptor material is 80000, that of the TsF activity is 27000 and 57000–64000, respectively. We thus were able to show that NP‐binding molecules can be obtained in the form of cellular surface receptors, isolated receptor material and extracted TsF from one and the same, monoclonal, cell source.
Demonstration of the stability of the membrane phenotype of T helper cells after priming and boosting with a hapten‐carrier conjugate
Authors: Spickett Gavin P. , Mason Don W. 
Published: February 2007

AbstractEvidence is presented that the phenotype of the rat T helper cells is stable after priming and boosting with a hapten‐carrier conjugate and that the phenotype is W3/25+, MRC OX‐22−, MRC OX‐8−. Data are also presented that demonstrate the presence of doubly marked, W3/25+, MRC OX‐8+, cells in the spleens of rats primed 1 week previously.