bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural aspects of immune recognition of lysozymes. III. T cell specificity restriction and its consequences for antibody specificity
Authors: Cecka J. M. , Stratton J. A. , Miller A. , Sercarz E. 
Published: February 2007

AbstractWe have studied the relationship between the determinants encountered by T cells on an antigenic molecule and the specificities of the antibodies eventually produced by the B cells with which these T cells cooperate. The number of epitopes on the hen lysozyme (HEL) molecule available to T cell receptors was functionally limited by inducing T cell tolerance to HEL in rabbits. Highly cross‐reactive lysozymes were then used to challenge the HEL‐unresponsive rabbits. Only T cells which recognize new epitopes on the challenge lysozymes could act as helpers in generating an anti‐lysozyme response.Amino acid differences between Japanese quail lysozyme (JEL) and HEL are segregated within a single quadrant of this small antigen molecule. HEL‐tolerant rabbits challenged with JEL produced antibodies which were totally cross‐reactive with the tolerogen HEL. This result is in contrast to the result obtained in nontolerant rabbits which produced antibodies to JEL which were only 50–70 % cross‐reactive with HEL. We conclude that T cells restricted to the JEL‐unique epitopes were only capable of cooperating with B cells specific for common epitopes shared between JEL and the tolerogen HEL. Turkey lysozyme (TEL), on the other hand, bears different amino acids which are distributed over several regions on the surface of the molecule. Any one HEL‐tolerant rabbit developed a restricted response to TEL; in some rabbits the anti‐TEL was highly HEL cross‐reactive, while in others little cross‐reactivity with HEL was observed. Each of four HEL‐tolerant rabbits injected with the minimally altered bob‐white quail lysozyme possessed the reactive T cells necessary to mount a limited response to this challenge lysozyme, suggesting a diverse library of T cell specificities. Recognition of the small differences between the challenge lysozymes and the tolerogen HEL required the T cells of these tolerant rabbits to make a fine discrimination between minimally changed epitopes.
Evidence for an absence of cross‐reactivity between human β ‐microglobulin and human IgG allotypes and subclasses
Authors: Colle A. , Tonnelle C. , Manuel Y. , Rivat L. , Ropartz C. 
Published: February 2007

AbstractSix β‐microglobulins were isolated from the urine of six patients with renal tubular dysfunction. Cross‐reactivity between these β ‐microglobulins and antigenic determinants of different IgG allotypes and subclasses was investigated. No evidence of cross‐reactivity was found. Some hypotheses are discussed concerning these results.
Role of early viral surface antigens in cellular immune response to vaccinia virus
Authors: Koszinowski U. , Ertl Hildegund 
Published: February 2007

AbstractInfection of mice with the vaccinia virus strain WR, Elstree or DIs, a conditional lethal mutant of vaccinia virus, resulted in the generation of vaccinia virus‐specific sensitized cytolytic T lymphocytes (CTL). It could be shown by cross‐reactivity between the three strains and by inhibition experiments with specific antisera that early vaccinia surface antigens are sufficient for the generation of specific CTL in vivo and for the lysis of infected target cells in vitro.
Antibodies to guinea pig lymphokines. III. Reactions with radiolabeled lymphocyte activation products
Authors: Sorg C. , Geczy Carolyn L. 
Published: February 2007

AbstractAn antiserum raised against a purified fraction of guinea pig lymphokines exhibits marked in vivo properties; it suppresses delayed hypersensitivity reactions and binds migration inhibition factor (MIF) from supernatants of activated lymphocyte cultures in vitro. This serum was analyzed for specificity using a radioactive double labeling technique which distinguishes products synthesized either de novo or in increased amounts by stimulated lymphocytes. Combined supernatants of stimulated (concanavalin A or PPD) and unstimulated cultures labeled with either tritiated or [14C]leucine, respectively, were fractionated on Sephadex G‐75. Pooled fractions were precipitated using the antibody sandwich technique, and solubilized precipitates were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Using this procedure the anti‐lymphokine serum recognized primarily three newly synthesized lymphocyte activation products with molecular weights of approximately 60 000, 45 000 and 30 000 daltons. By contrast, these molecules could not be detected in radiolabeled lymph node cells which had been solubilized with NP‐40 detergent. The isoelectric point of all three molecules was found to be 5.2 ± 0.3. The previously determined characteristics (mol.wt. 45 000, pI 5.2) of MIF and the property of the anti‐lymphokine serum to absorb MIF activity suggest an identity between MIF and one of the molecules. In view of the previously described in vivo effects of the anti‐lymphokine serum it is concluded that at least one of these three molecules plays an important role in the early events of delayed‐type hypersensitive reactions in vivo.
Restoration of immune responsiveness in early thymectomized Xenopus by implantation of histocompatible adult thymus
Authors: Tochinai S. , Nagata S. , Katagiri C. 
Published: February 2007

AbstractLarvae of the South African clawed toad, Xenopus laevis, were thymectomized at Nieuwkoop and Faber stages 45–46 (4–5 days after fertilization). The 1–1.5‐year‐old thymusless toads thus obtained were implanted with histocompatible thymus from 1‐year‐old toads, and 4 weeks later were given skin allografts or rabbit red blood cells (RRBC) to determine their immune response. In contrast with the perfectly tolerant thymusless controls, the thymus‐implanted toads rejected skin allografts after longer survival times (25–66 days) than the nonthymectomized controls (18–19 days). Accelerated rejection (15–27 days) of the second‐set skin allografts was evident in the thymus‐implanted individuals. Similarly, the capacity of antibody production against RRBC was restored to the thymus‐implanted toads to roughly the normal extent. Implantation of thymus also restored the histological features of the spleen in thymectomized toads. These experiments clearly demonstrate that in Xenopus the thymus plays an essential role for immunity at the early stages of its histogenesis. The restorative capacity of the adult thymus is also stressed.
Isolation of lymphocyte surface antigens. II. Identification of non‐β2‐microglobulin‐associated human T cell‐specific antigen
Authors: Zimmerman B. , Chapman M. L. 
Published: February 2007

AbstractIodinated cell surface components from human thymus lymphocytes labeled by the lactoperoxidase method, were solubilized by papain digestion and then 3 M KCl extraction of the residual cell pellet. Antiserum to human thymus bound three components from this material, mol. wt. ∼ 40 000, 20 000 and 12 000 daltons. This antiserum was absorbed with cultured human lymphoblasts (CHL) until it no longer bound CHL antigens or the HLA‐β2‐microglobulin complex. It continued to bind labeled antigens from thymus, peripheral blood lymphocytes and a “T” cell‐enriched fraction of tonsil lymphocytes. The absorbed antiserum bound a component from papain‐solubilized thymus antigens which had an estimated molecular weight of ∼ 40 000 daltons and which was not associated with β2‐microglobulin. This component seemed to be a human T cell‐specific antigen.
Structural and serological relationships among different antibodies from the same rabbit antiserum. I. Isolation, chemical and allotypic characterization of ten antibody components from one anti‐streptococcal serum
Authors: Aasted B. , Kindt T. J. 
Published: February 2007

AbstractThe relationships among antibodies produced by an individual rabbit were examined using multiple antibodies elicited by hyperimmunization with Group C streptococcal vaccine. Immunoadsorbent chromatography followed by agarose block electrophoresis yielded nine different antibody fractions, all directed against Group C carbohydrate, from the immune plasma of rabbit 4295 (allotype a1/b5). Electrophoresis of the antibody light chains gave single bands for most of the antibodies. Amino acid sequence analyses carried out on several of the antibody L‐chains revealed that five of these had aspartic acid at the amino terminus. By quantitative allotypic analyses all antibodies were allotype a1/b5. One antibody fraction, homogeneous by all other criteria, contained antibodies with two distinct group a allotypic subspecificities. The two antibodies in this fraction could be separated on an anti‐a1 column. The ten antibodies were placed into a minimum of three groups based on differences in a1 allotype subspecificity.
Affinity and specificity of penicillin‐antibody interaction determined by an enzyme (E. coli β‐galactosidase) immunoassay
Authors: Isetta Anna Maria , Minghetti A. , Radojkovic Jasna , Vasile Carla , Celada F. 
Published: February 2007

AbstractAn enzyme immunoassay (EIA) for a penicillin derivative is described with a sensitivity at least at the nanogram level. The label, E. coli β‐galactosidase is a macromolecule of 540 000 daltons: the size of the enzyme and the ease of linking penicilloyl residues to it make it an interesting model to study the effect of the degree of haptenic substitution (DS) in the tracer on the parameters of EIA. Our results show that the affinity of the binding reaction between antibody and tracer is proportional to the DS but the sensitivity of inhibition is not affected, at least not between 1 and 10 penicilloyl residues per GZ molecule. The theoretical consequences and practical applications of multivalent tracers in EIA are discussed.
The rapid onset of inhibition of antibody‐forming cell proliferation upon an increase in density of cellular suspensions cultured in vitro
Authors: Gurvich A. E. , Grigoryeva Olga 
Published: February 2007

AbstractIt was shown previously that the development of a primary immune response in vitro in the Mishell‐Dutton system was strongly inhibited by increased cell densities (Gurvich et al., Immunology 1975. 28: 271). In the present work, the rate of onset of this inhibition was studied in C57BL/6 mouse spleen cell suspensions during the phase of exponential increase of antibody‐forming cells (AFC) after 3 days' cultivation in vitro with the antigen. It has been shown that the increase in AFC number is very soon inhibited following an increase in the cellular density, the inhibition already being evident within 2 or 4 h. Parallel reduction in incorporation of radioactive precursors in DNA and especially RNA is observed, whereas inhibition of protein synthesis was delayed.
Immune response of New Zealand mice to trinitrophenylated syngeneic mouse red cells
Authors: Naor D. , Bonavida B. , Robinson R. A. , Shibata I. N. , Percy D. E. , Chia D. , Barnett E. V. 
Published: February 2007

AbstractNZB and NZB/W mice have reduced anti‐sheep red cell (SRC) and 2,4,6‐trinitrophenyl‐plaque‐forming cell (TNP‐PFC) responses with age after injection of either the thymus‐dependent antigen TNP‐SRC or the thymus‐independent antigen TNP‐mouse red cells (MRC). However, the thymus‐dependent response diminished much faster than the thymus‐independent response. As a consequence, young New Zealand mice have a higher anti‐TNP response after injection of TNP‐SRC than after injection of TNP‐MRC, while old New Zealand mice have a higher anti‐TNP response after injection of TNP‐MRC than after injection of TNP‐SRC. The PFC avidity of NZB/W mice injected with TNP‐SRC diminished with age, while the PFC avidity of mice injected with TNP‐MRC did not change with age. Young NZB/W did not produce anti‐MRC‐PFC after being injected with either TNP‐MRC or TNP‐SRC. Old NZB/W mice had few spontaneous anti‐MRC‐PFC. The number of anti‐VRC PFC in old mice was increased 4 to 10 times after injection with either TNP‐SRC or TNP‐MRC.It is suggested that surveillance mechanisms are responsible for suppressing the autoimmune response to modified self‐antigens. The unregulated immune system of NZB and NZB/W mice appears to be an expression of the impairment of such a hypothetical surveillance mechanism.
Effect of prior sensitization with hapten on the antibovine IgG antibody response to hapten‐conjugated tolerogen of mice tolerized by low doses of bovine IgG
Authors: Leech S. H. , Mitchison N. A. 
Published: February 2007

AbstractMice tolerized by low doses of bovine IgG (BGG), immunized with arsanilated (ARS) conjugates and challenged with ARS‐BGG show an augmented anti‐ BGG antibody response compared with controls immunized with nonconjugated carrier. Conditions optimal for generating hapten help are explored and suggest that the phenomenon is mediated by hapten‐specific helper T cells.During exploration of these conditions it became apparent that the response was suppression rather than augmentation with ARS, under certain circumstances, and with 2,4‐dinitrophenyl, 4‐hydroxy‐5‐iodo‐3‐nitro‐phenylacetyl (NIP) and sulfanilic acid, under all conditions tested. Especially important in determining the outcome of the interaction was the type of adjuvant used for hapten priming. The significance of these observations is discussed in relationship to the balance between negative and positive cooperation.
Helper cell function of primed T cells. II. T‐T cell Synergism between Ig+ and Ig− subpopulations of primed thymocytes: a mechanism for amplification of helper cell function
Authors: Paraskevas F. , Lee S. T. 
Published: February 2007

AbstractThymocytes collected from spleens of lethally irradiated and thymocyte‐reconstituted mice, 6 h after “education” with SRBC, exert a markedly augmented helper cell function, especially for the 7 S response. Pretreatment of primed thymocytes with a rabbit anti‐mouse Ig serum and complement abolished the augmented helper cell function, although it had no effect on unprimed cells. Treatment of 6 h primed T cells with an anti‐Θ serum and complement also abolished the augmented helper cell function. However, in striking contrast with unprimed T cells where such treatment entirely abolished the helper cell function, the anti‐Θ treated 6 h T cells are still able to provide a significant helper cell function of the same magnitude as untreated nonprimed cells. This result suggests that a T cell subpopulation 6 h after priming becomes resistant to lysis by anti‐Θ serum and supports a substantial helper cell function. Since the sum of plaque‐forming cells (PFC) given by anti‐Ig and anti‐Θ‐treated 6 h primed cells was far smaller than the PFC given by untreated cells, a T‐T synergism is implicated as a mechanism for the augmented helper cell function of 6 h primed thymocytes.The amplification was also eliminated following treatment with a mouse anti SRBC serum indicating that some primed cells carry antigen on their surface. The data from various recombinations of primed cells treated with one of these three antisera, as well as primed cells treated sequentially with various combinations of two of the three antisera, suggested that the Ig+ and antigen‐carrying cells belong to the same subpopulation which is resistant to lysis by anti‐Θ serum. These cells are distinct from the rest which remain Ig− and still sensitive to lysis by anti‐Θ serum (Θ+).The Ig and antigen most likely represent a cytophilic complex present on the surface of a subpopulation of T cells. Thymocytes collected 5 days after education show little or no synergistic effect.The T‐T cell synergism described here may represent a basic regulatory function of T cells.
Independence of the antigen‐binding site and the VHa allotypic determinants of rabbit anti‐pneumococcal anti bodies
Authors: Jaton J.‐C. , Schweizer Marianne , Knight Katherine L. 
Published: February 2007

AbstractThe interaction of VHa allotypic determinants and the antigen‐binding site of rabbit anti‐pneumococcal antibodies was investigated. Homogeneous type 3 pneumococcal antibodies of known allotype were used as inhibitors of the reference Ig allotype‐anti‐allotype reaction in the presence and absence of oligosaccharide determinants derived from type 3 pneumococcal polysaccharide by partial acid hydrolysis. The results of the present studies indicate that conformational changes of antibody caused by antigen binding do not influence the expression of the allotypic determinants of the VH region. Similarly the binding of the anti‐allotypic antibody does not alter the association constant of the complexed antibody for a hexasaccharide ligand. The location of the structural correlates of the allotypic specificities is considered following an examination of a hypothetical three‐dimensional model of a rabbit antibody.
Decreased “natural killer” effect in tumor‐bearing mice and its relation to the immunity against oncorna virus‐determined cell surface antigens
Authors: Becker Susanne , Klein Eva 
Published: February 2007

AbstractIn comparison to control animals the natural killer (NK) efficiency of spleen and blood lymphocyte population was reduced in three systems of tumor‐bearing animals: transplanted methylcholanthrene (MC) and primary Moloney sarcoma virus (MSV) induced sarcomas in CBA mice, and athymic “nude” mice carrying grafts of human lymphoblastoid cell lines. No evidence for suppressor cells was found. After regression of the MSV tumors the activity was high again. The effect was measured on YAC ‐ a culture line of a Moloney leukemia virus‐induced lymphoma in an A mouse ‐ which is highly sensitive to the NK effect.Against another lymphoma, RBL‐5, (Rauscher leukemia virus induced in C57BL mice), the effect of control spleen cells was low while that of the MSV tumor‐bearing spleen cells was high, indicative of immunization effect. With regard to the virus‐induced antigens, YAC and RBL‐5 cross‐react. Analysis of the NK effector population indicated that anti‐YAC killer cells are enriched after passage through nylon wool. This would indicate a cytotoxic role of T cells. However, treatment with anti‐RBL‐l.2 serum did not markedly influence the effect. On the other hand, anti‐RBL‐5 activity of spleens from tumor‐bearing (CBA × C57BL)F1 mice decreased after removal of Thy‐1.2‐positive cells. YAC thus seems to be more sensitive to the NK effect, while RBL‐5 to the T cell‐mediated immune effect.Cytotoxic lymphocytes for YAC and RBL‐5 could be isolated from MSV tumors of CBA but not of A mice in spite of the regularly occurring regression also in the latter strain.
A new system for highly efficient generation of alloantigen‐specific cytotoxic T cells
Authors: Pilarski Linda M. , Borshevsky Ludmilla V. 
Published: February 2007

AbstractA tissue culture system for generating alloantigen‐specific cytotoxic T cells is described which utilizes Marbrook polyacrylamide rafts as the culture vessel. The system has the following properties.
Cytotoxic T cells are generated after culture of very low numbers of responder lymphocytes. Cultures routinely contain 0.5 × 106 ‐ 1 × 106 responder cells but as few as 3 × 104 lymphocytes/culture generate significant cytotoxicity.
Generation of cytotoxicity is efficient at all cell doses, producing killer cells effective at lymphocyte‐to‐target ratios of from 0.03: 1 to 5:1. The lowest ratio represents cytotoxicity by the progeny of only 833 lymphocytes.
)The number of cells in cultures increases rather than decreases over the five‐day culture period yielding a 2–4‐fold average increase in viable cells.
Role of self‐carriers in the immune response and tolerance. Parameters of tolerance induced by haptenated lymphoid cells
Authors: Long Carol A. R. , Scott D. W. 
Published: February 2007

AbstractThe induction of tolerance to the 2,4,6‐trinitrophenyl (TNP) hapten has been studied in a system utilizing haptenated syngeneic lymphoid cells. Specific depression of the direct and indirect plaque‐forming cell (PFC) responses to TNP‐protein conjugates was regularly achieved by pretreatment of Lewis rats with 1 × 107 trinitrophenylated spleen cells or TNP lymph node cells. Very low numbers of haptenated lymphocytes were active since tolerance could be induced in vivo with as few as 105−106 TNP spleen cells (SC). SC exposed to as little as 10–100 μg of the reactive hapten, trinitrobenzene sulfonic acid, were effective tolerogens in this system. Tolerance induced with 107hapten‐ated spleen cells persisted for at least 4 weeks. Viable intact cells did not seem to be required in this system since the cell‐free supernatants from TNP‐SC cultured for 24 h were also active. In addition, significant depression of an ongoing immune response could also be imposed by haptenated isologous lymphoid cells. Moderate suppression of the “hapten‐specific” delayed hypersensitivity response (measured by the accumulation of 51Cr‐labeled bone marrow cells) was also achieved with TNP‐SC. These results suggest that haptenated isologous lymphoid cells are potent tolerogenic conjugates capable of inducing tolerance affecting antibody formation and delayed hypersensitivity. However, since we and others have shown that TNP‐SC do not adversely affect the generation of hapten‐specific cytotoxic T cells, it is postulated that there is a differential recognition of, or response to, hapten‐modified self‐carriers by functionally distinct lymphocyte subpopulations.
Autoimmune murine thyroiditis. Relationship of humoral and cellular immunity to thyroiditis in high and low responder mice
Authors: Tomažič Vesna , Rose N. R. 
Published: February 2007

AbstractGood responder (C57Br/cd) and poor responder (C57BL/10) mice were immunized with mouse thyroid extract in Freund's complete adjuvant. The good responder mice first showed antibody to thyroglobulin on the seventh day while the poor responder animals had slightly lower titers and antibody did not appear until day 12. The first signs of thyroid infiltration appeared on day 4 in the responder strain, and severe lesions were seen between the third and fifth week. In contrast, the poor responder mice showed almost no evidence of infiltration. The macrophage disappearance reaction, a measure of cell‐mediated immunity, was similar in the responder and nonresponder strains.
T lymphocyte induction of non‐T cell‐mediated nonspecific cytotoxicity. Introduction mechanisms
Authors: Mackler B. F. , O'Neill Peggy A. , Meistrich M. 
Published: February 2007

AbstractMononuclear cells (MNC) from normal humans consistently failed to give nonspecific cytotoxic responses. However, after removal of T cells by sheep erythrocyte (E) rosetting, the remaining non‐RFC (rosette‐forming cells) now gave significant nonspecific cytotoxic responses against both autologous and allogeneic target cells. Reconstitution experiments with T cell subpopulations failed to suppress these nonspecific non‐E ‐RFC‐mediated cytotoxic responses. There was also no evidence to indicate the involvement of antibody in this nonspecific cytotoxicity. The cytotoxic cells were characterized as non‐E ‐rosetting, non‐phagocytic, and glass adherent lymphocytes; no evidence of monocyte‐macrophage participation was found.The inductive trigger of non‐E ‐RFC‐mediated cytotoxicity was found to be soluble factors released by T cells during E‐rosette formation at 4°C. Incubation of MNC with horse, marmoset and human erythrocytes under identical conditions failed to trigger cytotoxicity. The incubation of quiescent MNC with E‐rosetting supernatants (ERS) induced nonspecific cytotoxic responses equivalent to those mediated by separated non‐E ‐RFC. ERS‐activated MNC destroyed both autologous and allogeneic target cells. The ERS supernatants themselves were not cytolytic. These findings suggested that cell separation procedures, and possibly in vivo events, which activate T cells may also induce non‐T cell‐mediated nonspecific cytotoxicity.