bluuebunny/crossref_metadata_2025_split huggingface dataset:
Major histocompatibility gene complex (MHC)‐coded determinants on antigen‐specific suppressor factor for delayed‐type hypersensitivity and surface phenotypes of cells producing the factor
Authors: Liew Foo Y. , Sia Dwo Y. , Parish Chris R. , McKenzie Ian F. C. 
Published: February 2007

AbstractAntigen‐specific suppressor factor for delayed‐type hypersensitivity (DTH) to sheep red blood cells (SRBC) was obtained by incubating in vitro spleen cells from CBA mice (H‐2k) injected intravenously 3 days previously with 1 × 109 SRBC. The suppressor factor was characterized for major histocompatibility gene complex (MHC)‐coded antigenic determinants by passing the factor through immunosorbents coupled with appropriate alloantisera. The suppressor factor was absorbed by anti‐H‐2k, anti‐Iakand anti‐I‐Jk immunosorbents but was not retained by anti‐IaS, anti‐I‐JS, anti‐I‐Ak, anti‐I‐E/C′ or anti‐H‐2Kk immunosorbents. In addition, the factor bound to an immunosorbent coupled with rabbit antibodies against carbohydrate‐defined Ia antigens. Furthermore, the suppressive activity that was absorbed was quantitatively recovered in the acid eluates from the immunosorbents. Treatment of the spleen cells with anti‐Lyt‐1.1 antiserum and complement completely abrogated their ability to elaborate the suppressor factor in vitro. In contrast, treatment with anti‐Lyt‐2.1 or anti‐Iak antiserum and complement had no effect. Thus, it appears that the suppressor factor for DTH to SRBC bears I‐J subregion‐coded determinants, and its production is dependent on cells which have the Lyt‐1 +,2− and Ia− phenotype.
Accelerated age‐dependent decline in the T suppressor capacity of SJL mice
Authors: Nakano Katsuji , Cinader Bernhard 
Published: February 2007

AbstractTolerance induction with rabbit gamma‐globulin was employed as a probe for age‐ dependent changes in suppressor capacity of SJL lymphoid cells. The tolerant state was assessed by loss of cooperative capacity and by infectious tolerance. The supply of precursor cells was assessed by thymectomy and by treatment with colchicine and cyclophosphamide, which have been reported to eliminate suppressor cells. Thymectomy, 16–18 days before tolerance induction, did not affect antibody responses or tolerance inducibility; thymectomy, 33 days before tolerance induction, reduced both antibody response and tolerance inducibility. Colchicine, injected together with aggregate‐freed rabbit gamma‐globulin, inhibited tolerance induction partially in 35‐ day‐old mice and completely in 106‐day‐old mice. Colchicine, given to younger mice, thymectomized 17 days before tolerance induction, prevented tolerance induction completely. A low dose of cyclophosphamide interfered with tolerance induction in older, but not in younger mice. A high dose of cyclophosphamide interfered with tolerance induction in thymus cells of younger and older mice. After thymectomy, there was a much more profound interference of a low dose of cyclophosphamide with tolerance induction. Results were discussed in terms of an age‐dependent decline of thymus progenitors and of peripheral progenitors of suppressor cells.
Macrophage requirement for in vitro generation of specific, secondary cell‐mediated cytotoxicity against SV40‐induced tumor‐associated antigens in mice
Authors: Glaser Moshe 
Published: February 2007

AbstractThe role of adherent phagocytic cells in an in vitro secondary cytotoxic response against Simian virus 40 (SV40)‐induced tumor‐associated antigens was investigated. Spleen cells (responder cells), from mice primed with syngeneic SV40‐transformed cells, extensively depleted of macrophages by filtration through a Sephadex G–10 column followed by iron carbonyl treatment, had a markedly decreased capacity to generate in vitro secondary cytotoxic reactivity against syngeneic SV 40‐transformed cells when cultured with the relevant stimulator cells. The secondary response was restored by the addition of adherent peritoneal cells from normal mice syngeneic to those immunized with the antigen. Within a certain dose range, small numbers of peritoneal cells completely reconstituted the response, whereas large numbers inhibited the reactivity. The restored cultures maintained specific cytotoxic reactivity against SV40‐induced tumor‐associated antigens which was mediated by effector T cells as shown by sensitivity to anti‐Thy‐1.2 antiserum and complement. These results suggested a requirement for adherent phagocytic cells (accessory cells) in in vitro generation of a secondary, cytotoxic response to tumor‐associated antigens.
Solubilization of complexes between tumor‐associated and H‐2 antigens from a tumor cell plasma membrane
Authors: Honeycutt Pamela J. , Gooding Linda R. 
Published: February 2007

AbstractThe tumor‐associated cell surface antigens (TAA) gp71 and AgI cocap H‐2, but are not associated with H‐2 following solubilization of membranes with detergent. We have attempted to solubilize intact TAAIH‐2 complexes from surface‐labeled L cells using decreasing concentrations of the nonionic detergent Nonidet‐P40 (NP40). Associations between gp71 and H‐2 and between AgI and H‐2 in solution were detected using sequential immunoprecipitation. gp7UH‐2 and AgI/H‐2 complexes were solubilized at the lowest detergent concentration used, 0.01% NP40. No co‐ precipitation of these antigen pairs was seen at any higher NP 40 concentration tested. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that precipitation of antigens solublized in 0.01% NP40 leads to co precipitation of a small number of other protein peaks and does not appear to involve wholesale inclusion of labeled membrane proteins. These results, together with previous observations of cocapping between TAA and H‐2 antigens, suggest that the molecules are associated with one another in the membrane. Detergent solubilization of membranes with all but the most gentle conditions leads to disruption of these complexes.
Hapten‐specific helper T cells. I. Collaboration with B cells to which the hapten has been directly coupled
Authors: Martinez‐Alonso Carlos , Coutinho António , Bernabé Rosa R. , Augustin Andrei , Haas Werner , Pohlit Helmut 
Published: February 2007

AbstractA new system to obtain large numbers of functionally competent hapten‐specific effector helper T cells has been developed. Mice were primed in the tail with syngeneic spleen cells derivatized with one of three different haptens: 2,4,6‐trinitrophenyl, fluorescein isothiocyanate and 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl. Draining lymph node cells were subsequently restimulated in culture with the homologous antigen for periods up to 6 weeks. More than 99% and 90% of the cells recovered from these preparative cultures, expressed Thy‐1 and Lyt‐1 antigens, respectively. These cells proliferated specifically in response to the homologous stimulation by haptenated syngeneic spleen cells, and they were found to display very high levels of hapten‐specific helper activity, as assayed in a new, universal method for testing T ‐ B cell cooperation, where every B cell can potentially respond to specific T cell help. Coculture of hapten‐derivatized, functionally competent B cells with hapten‐specific T cells obtained from the preparative cultures, resulted in the appearance, and exponential increase with time, of very large numbers of IgM and IgG plaque‐forming cells. This helper activity could be shown to be: specific for the immunizing hapten and to increase with the time of in vitro helper cell enrichment, which also resulted in higher average avidities expressed by the helper cell populations. This methodology appears valuable for structural studies on hapten‐specific helper cells, as well as for the functional analysis of effector helper ‐ B cell interactions.
Hapten‐specific helper T cells. II. Genetic determination of functional recognition
Authors: Martinez‐Alonso Carlos , Coutinho António , Bernabé Rosa R. , Haas Werner , Pohlit Helmut 
Published: February 2007

AbstractHelper T cells can be raised in CBA mice with specificity for syngeneic spleen cells derivatized with each of the three haptens, trinitrophenyl (TNP), fluorescein isothiocyanate (FITC) and 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl (SP). These helper cells are exquisitely specific for the homologous antigens, since they express helper activity on target B cells derivatized with hapten concentrations 100‐fold lower than those used for priming, while being totally unable to recognize the heterologous hapten modifications. Expression of helper activity, i.e. induction of target B cells, requires the simultaneous recognition of antigen and I‐A‐ or I‐E/C‐encoded determinants directly on the responding B cell surfaces.Helper T cells raised in DBA/2 mice with specificity for the same hapten modifications, while functionally recognizing as efficiently as CBA helper cells densely coupled target cells, fail to interact with syngeneic cells derivatized with low concentrations of any of the three haptens. Furthermore, DBA/2 helper cells show a unique “fine specificity” pattern in that anti‐FITC DBA/2 helpers cross‐react with TNP‐DBA/2 targets.
Natural killer cells are responsible for the interferon production induced in human lymphocytes by tumor cell contact
Authors: Timonen Tuomo , Saksela Eero , Virtanen Ismo , Cantell Kari 
Published: February 2007

AbstractThe identity of cells producing interferon among human peripheral blood lymphocytes in contact with tumor cells was investigated. The producer cells were target cell‐adherent lymphocytic cells morphologically similar to natural killer (NK) cells. As interferon is known to augment the cytotoxic activity of initially inactive “pre‐NK” cells, the results suggest an internal positive feedback mechanism in the activation of NK cells.
Interaction of lectins with human T lymphocytes mitogenic properties, inhibitory effects, binding to the cell membrane and to isolated surface glycopeptides
Authors: Dillner‐Centerlind Marie‐Louise , Axelsson Bernt , Hammarstrom Sten , Hellström Ulla , Perlmann Peter 
Published: February 2007

AbstractThe mode of interaction of twelve lectins with human T lymphocytes was investigated. In order to establish possible differences between mitogenic and nonmitogenic lectins, they were studied for their capacity to induce or inhibit DNA synthesis. Their interaction with intact T cells was studied by immunofluorescence and 51Cr release. Further, lectins conjugated to Sepharose were investigated with regard to their capacity to bind surface glycopeptides from T cell lysates. Operationally, the lectins could be divided into three groups: (a) mitogenic lectins; (b) lectins inhibitory for lymphocyte mitogenesis as induced by leucoagglutinin (La) from Phaseolus vulgaris; and (c) nonmitogenic lectins which were noninhibitory in this La system. Six lectins were nonmitogenic. For two or possibly three of these, lack of mitogenicity was due to complete or partial failure to bind to the lymphocytes. This explanation could not account for lack of mitogenicity of the other three nonmitogenic lectins. Only two of the lectins utilized inhibited La‐induced mitogenesis. However, when the lectins were compared with regard to their capacity to bind surface glycopeptides from T cell lysates, important differences between mitogenic and nonmitogenic lectins were seen. As revealed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate and autoradiography, the mitogenic lectins bound a larger number of surface glycopeptides (15–20) than the nonmitogenic lectins (3–10). More importantly, five distinct glycopeptides (gp 135 K, 125 K, 105 K, 95 K and 43 K) were bound by all mitogenic lectins but not by the nonmitogenic lectins. It remains to be established whether these glycopeptides are present on the T cells which are susceptible to the mitogenic action of the lectins and whether it is the interaction of the lectins with one or several of them which triggers mitogenicity.
Cellular requirements for the in vitro induction of specific suppression of antibody responses by immune spleen cells
Authors: Calkins Catherine E. , Stanton Thomas A. , Stutman Osias 
Published: February 2007

AbstractFeedback regulatory signals to an intermediary suppressor cell may provide the mechanism of the suppression of antibody responses which has been described in cocultures of primed (immune) and unprimed (normal) spleen cells. The active cell(s) in the unprimed spleen population is nonadherent to nylon wool, Sephadex G‐10 and glass beads. Lymph node cells and cortisone‐resistant thymocytes from normal animals act similarly to normal spleen cells in this coculture system. Spleen cells from homozygous nude mice, unlike their heterozygous thymus‐bearing littermates, do not produce a high degree of suppression in coculture with immune spleen cells. These data strongly suggest that the normal cell which interacts with primed cells in the cocultures to produce suppression is of thymic origin. However, spleen cells from neonatally thymectomized mice are suppressive in the presence of spleen cells immune to sheep red blood cells. The unprimed cell(s) active in the suppression are sensitive (in the presence of complement) to antisera directed against the surface markers, Thy‐1, Qa‐1, Lyt‐1, Lyt‐2, and Ia. Most of the antiserum treatments abrogated the suppressive capacity of the normal spleen cells only partially. Only treatment with anti‐Qa‐1 and complement routinely eliminated the ability of these cells to suppress in the cocultures suggesting either low concentration of or inaccessible surface alloantigen on the active cells. Alternatively, more than one Qa‐1‐positive cell set from the unprimed population may be involved. It is postulated that there is at least one subset of Qa‐1‐positive T lymphocytes present in unprimed spleen and lymph node cell populations capable of participating in the suppression of specific secondary antibody responses when cocultured with spleen cells from specifically primed animals.
Interactions between a novel cell surface glycoprotein and the H‐2K and H‐2D antigens on myeloma tumor cells
Authors: Celis Esteban , Eisen Heman N. 
Published: February 2007

AbstractPrevious studies have shown that when a subline of plasmacytoma LPC‐1 is grown in ascites form, the tumor cells harvested after 10–12 days (“late” cells) are resistant to lysis by cytotoxic T lymphocytes (CTL), apparently because the cell surface H‐2‐encoded molecules are blocked by a trypsin‐sensitive glycoprotein of approximately 160 kdaltons. The glycoprotein (gp 160) is produced, and accumulates on the cell surface, as the growing cells enter the stationary phase. In contrast, LPC‐1 cells harvested from the peritoneal cavity early in the transplantation cycle (ca. 4 days), while in exponential growth (“early” cells), have far less gp 160 and are susceptible to lysis by CTL. It is shown that, compared with early cells, the late LPC‐1 cells are far less effective in adsorbing antibodies to products of the H‐2 Kd and H‐2 Dd alleles, but only slightly less effective in adsorbing antibodies to la antigen, and fully effective in adsorbing antibodies to several antigens not related to H‐2 (e.g. PC.1, gp70, gp100, B220). The differences suggest that gp160 might preferentially block H‐2‐encoded molecules (especially K and D)Gp160 was also detected on another myeloma, MOPC 315 OPEC, a subline of MOPC 315, where it also appeared to block H‐2 molecules but not PC.1. Additional evidence for an interaction between gp160 and H‐2 molecules was obtained when sonicated membrane fragments were used to elicit secondary CTL responses to H‐2 in culture. The response could be elicited by fragments from early but not from late LPC‐1 cells, unless the late cells were treated with subtilisin (to remove gp 160) before sonication.
Analysis of immunoglobulin chain secretion using hybrid myelomas
Authors: Wilde C. Deborah , Milstein Cesar 
Published: February 2007

AbstractThree different approaches have been used to study nonsecreting variants of myeloma and hybrid myeloma lines. Hemolytic plaque assays were used to screen nonsecreting and light (L) chain‐secreting anti‐sheep red blood cell hybrid myeloma variants for reversion to specific antibody or immunoglobulin (Ig) production. No revert ants were detected from among 1.5 × 107−4.2 × 107 cells of each line studied. In the absence of a heavy (H) chain, the P3 (MOPC 21) x chain is not secreted but degraded intracellularly. The nature of this secretion defect was investigated in a hybrid myeloma line that produces the P3 x chain and another L chain which is secreted without an H chain, by biochemical studies of the relative distribution of mRNA activity for the two L chains between membrane‐bound and free polysomal fractions. The mutant P3 H chain (H*) produced by the line P3‐NSII/1 is also degraded intracellularly rather than secreted. This defect was complemented by cell fusion of P 3‐NSII/1 to P1, a different Ig‐secreting myeloma line. Mutant H* chains were only secreted as part of hybrid Ig molecules with P1 L chains indicating that the defect in their secretion in the P 3‐ NSII/l line was due to lack of a complementary Ig chain. Additionally, the preferential recovery of P1 H chain loss variants from these hybrids that are producing two H chains and only one L chain, supports the idea that free intracellular H chains have an effect on cell viability and influence the type of variants recovered from hybrid myeloma lines.
Differential sensitivity to cyclophosphamide of helper T cells for humoral responses and suppressor T cells for delayed‐type hypersensitivity
Authors: Shand Frank L. , Liew Foo Y. 
Published: February 2007

AbstractThe relative sensitivity to cyclophosphamide (CY) of helper T cells in antibody responses and of suppressor T cells in delayed‐type hypersensitivity (DTH) responses against sheep red blood cells (SRBC) was measured by pretreating cell suspensions in vitro with the microsomally activated form of CY and evaluating their subsequent function in transfer experiments. It was found that suppressor T cells involved in DTH responses were sensitive to much lower concentrations of activated CY than were helper T cells for anti‐SRBC antibody responses. Since the cytotoxic activity of CY is thought to be dependent on its ability to alkylate nuclear DNA, the differential sensitivity observed may be more easily explicable in terms of additional secondary enzyme‐mediated degradation or DNA repair mechanisms.
Possible mechanism of target cell resistance in antibody‐dependent cellular cytotoxicity
Authors: Lavrovsky Vadim A. , Viksler Victor K. 
Published: February 2007

AbstractThe rate of disappearance of anti‐H‐2 antibodies from the surface of target cells varies in different cell types. It sharply increases in the presence of spleen cells, i.e. of cells which effect the antibody‐dependent cellular cytotoxicity (ADCC). Xenogeneic serum produces a stronger ADCC reaction than does aliogeneic serum, aid the antibodies of the former are lost by the target cells at a slower rate than those of the allogeneic serum. The rate of disappearance of the antigen‐antibody complexes from the target cells may limit the efficiency of the ADCC.
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

AbstractThe 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

AbstractFully 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

AbstractIn 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.