bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibodies to guinea pig lymphokines. III. Reactions with radiolabeled lymphocyte activation products
Authors: Sorg C. , Geczy Carolyn L.
Published: February 2007

An 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

Larvae 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

Iodinated 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

The 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

An 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

It 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

NZB 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

Mice 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

Thymocytes 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

The 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

In 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

A 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

The 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

Good 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

Mononuclear 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.
Suppressor T cells in low zone tolerance I. Mode of action of suppressor cells
Authors: Stumpf R. , Heuer J. , Kölsch E.
Published: February 2007

Low zone tolerance (LZT) to bacteriophage fd seems to be a type of tolerance which is primarily caused by suppressor T cells. The aim of this paper is to analyze their mode of action. For the induction of antigen‐specific suppressor cells in hydrocortisone pre treated CBA mice, we use tolerogenic and immunogenic doses of antigen. Suppressor activity can be demonstrated upon transfer of spleen cells into normal syngeneic mice. After immunization these animals are unable to produce IgG antibody against phage fd, whereas the IgM response is not suppressed. The half‐life of transferred suppressor cells in nonimmunized animals is 5–6 weeks. The target of suppression are unprimed T helper cells, whereas primed helper cells cannot be blocked. T helper cells become ‘resistant’ to suppression 18–3 6 h after contact with antigen. Differentiation from unprimed B into B memory cells is unaffected, yet under suppression conditions persisting B memory cells are blocked in IgG production. The experimental data are incorporated into a model of LZT.
Analysis of the antigenic structure of the thymocyte surface membrane by heterologous anti‐thymocyte serum
Authors: Arndt R. , Thiele H.‐G. , Stark Rosemarie , Wottge H.‐U. , Müller‐Ruchholtz W.
Published: February 2007

The surface membrane of rat thymocytes and lymph node cells was analyzed by comparing the capability of different rat cell types and of solubilized and chromatographically separated rat thymocyte membrane fractions to absorb cytotoxic antibodies on rat thymocytes and lymph node cells from a heterologous anti‐rat thymocyte serum. The experiments described cause distinct antigenic specificities of the thymocyte membrane to be brought into relationship to structures of defined physico‐chemical properties, and thus are an approach of a thymocyte cell surface mapping in antigenic as well as in molecular terms. Furthermore, the data presented allow conclusions on the distribution pattern of single antigenic determinants on different cells or tissues used as absorbents and target cells.
The induction of specific resistance in F1 hybrid rats to local graft‐vs.‐host reactions: nature of the eliciting cell
Authors: Woodland R.T. , Wilson D.B.
Published: February 2007

A specific state of resistance to local graft‐vs.‐host (GVH) reactions can be induced in F1 hybrid rats, derived from Ag‐B incompatible matings, as a consequence of inoculation with low numbers of parental strain lymphocytes. The magnitude of GVH resistance is markedly and directly dependent upon the number of parental strain lymphocytes used in the pretreatment regimen. The relevant constituents of the resistance‐inducing parental cell population are thymus‐derived (T) lymphocytes possessing immunologic competence for host alloantigens. B cells, themselves incapable of inducing GVH resistance, adversely effect the induction or display of this effect by T cells.
Separation of cells with different histocompatibility (H‐2) antigens by passage through cellular immunoadsorbent columns
Authors: Dalianis Tina , Andersson B. , Klein G.
Published: February 2007

The anti‐Ig column technique of Wigzell et al. (Scand. J. Immunol. 1972. 1: 75) was adapted to the separation of mouse cells with different H‐2 antigens. Fractionation was achieved by a two‐step procedure: first the cells were treated with anti‐H‐2 sera, and thereafter passed over anti‐mouse Ig columns. Antibody‐coated cells were selectively retained in the anti‐Ig column. The method could be applied to the separation of normal mouse lymphocytes or lymphoma cells with different H‐2 antigen complexes and for the selective isolation of H‐2 loss variants from a mouse carcinoma/fibroblast hybrid.
The induction of hapten‐specific T cell tolerance using hapten‐modified lymphoid membranes II. Relative roles of suppressor T cells and clone inhibition in the tolerant state
Authors: Miller S.D. , Sy M.‐S. , Claman H.N.
Published: February 2007

The cellular nature and specificity of suppressor cells and the mechanisms of tolerance to 2,4‐dinitrophenyl‐l‐fluorobenzene (DNFB) in mice was investigated. Mice tolerized with hapten‐modified self membrane, i.e. dinitrophenylated spleen cells (DNP‐SC), generated suppressor cells as shown by their ability to transfer unresponsiveness to normal animals. Such suppressor cells were specific for DNFB as they did not interfere with sensitization of normal animals with 2,4,6‐trinitro‐1‐chlorobenzene (picryl chloride). These suppressor cells were of the thymus‐derived lymphocyte (T cell) lineage as (a) their activity was abolished by treatment with anti‐Θ serum plus complement, and (b) these cells could not be raised in T cell‐deprived mice. Kinetic studies of the development of tolerance showed discrepancies between the rate of induction of unresponsiveness in the donor (“phenotypic” tolerance) and the ability to transfer tolerance. One day after receiving 5 × 10 DNP‐SC mice were phenotypically tolerant but could not serve as the donors of suppressor cells. 7 days after tolerization with DNP‐SC mice were still fully tolerant and also contained suppressor cells, which were no longer demonstrable 14 days after tolerization when mice were still phenotypically tolerant. The ability to transfer tolerance was eliminated by pretreatment with cyclophosphamide (Cy). We postulate that two independent mechanisms of tolerance occur after tolerization with DNP‐SC ‐ the rapid induction of clone inhibition and the slower, transient induction of suppressor T cells. Cy had no effect on clone inhibition but eliminated the precursors of suppressor T cells.
A heterophile carbohydrate moiety common to mammalian IgM and erythrocytes detected by chicken IgM antibody
Authors: Ivanyi J. , Strudwick Linda , Makings C.
Published: February 2007

Sequential treatment of chicken lymphocytes with normal sheep serum (NSS), chicken antiserum against sheep erythrocytes (SE) and formaldehyde results in rosette formation with SE. The identity of reactive components and the mechanism of rosette formation has been elucidated. The binding activity of NSS to chicken lymphocytes was ascribed to “natural” IgM anti‐species antibodies. Subsequently, chicken IgM anti‐SE antibody reacted with sheep IgM bound to the lymphocyte surface, and, following formaldehyde fixation, rosettes were formed by the addition of SE. The reaction of chicken anti‐SE antibody was competitively inhibited with a hog blood group substance suggesting that it had binding specificity for a carbohydrate moiety which is shared by sheep IgM and SE. This specificity represented only a fraction of the bulk of chicken IgM anti‐SE antibodies and was not manifested by antibodies of the IgG class. The analysis by the above‐described “sandwich rosette assay” was extended to chicken antisera against horse, rat and mouse red cells and to normal sera from these species. Cross‐matching of chicken antisera, with the normal sera and red cells from the tested species revealed a distinct pattern of cross‐reactivities. These results imply that the saccharide epitope which is shared by IgM and red cells has a wide distribution between various mammalian species and may be classified as a new system of heterophile antigens.
Genetic control of contact sensitivity to oxazolone in inbred, H‐2 congenic and intra‐H‐2 recombinant strains of mice
Authors: Fachet J. , Andó I.
Published: February 2007

Delayed‐type hypersensitivity (DTH) to 2‐phenyl‐4‐ethoxymethylene‐5‐oxazolone (oxazolone) was found to be under multigenic control in inbred, H‐2 congenic and intra‐H‐2 recombinant strains of mice. A high response was associated with haplotypes H‐2d,a,k and low response with haplotype H‐2b.

DTH to oxazolone was high or intermediate in different F1 hybrids of high and low responder mice. In F2 and backcross generations a higher response was associated with the “dd”, than with the “bb” phenotype, while intermediate response was found in the heterozygote “db” mice.

A study of H‐2 recombinant strains suggests that a gene controlling the DTH response maps in the I‐B subregion of the H‐2 complex. The response was significantly modified by gene(s) which are not linked to the H‐2 complex and have not been mapped.

Since congenitally athymic nude (nu/nu) mice did not respond to oxazolone, this contact sensitivity is belived to be a T cell‐dependent immune response.
Evaluation of the possible role of B cell receptors in the tendency of B cells to migrate into follicles in mice and chickens*
Authors: De Kruyff Rosemarie H. , Ponzio N.M. , Jeanette Thorbecke G.
Published: February 2007

Chicken spleen and bursa cells were examined for the percentage of Fc receptor‐bearing cells. Rosette formation was done with chicken 7S antibody‐sensitized sheep erythrocytes and was inhibited by heat‐aggregated chicken Ig. In the spleen, the percentage was found to increase with age to ∼ 26 % at 7 to 12 weeks. In contrast, only 3 to 5 % of bursa cells at this age demonstrated Fc receptors. Spleens from bursectomized chickens had 7–10 % Fc receptor‐bearing cells.

In an attempt to determine a possible role of the C3 receptor on migration patterns, the effect of cobra venom factor (CVF) on the localization of transferred lymphoid cells was examined. Pretreatment of recipients with enough CVF to lower mean C3 levels to 11 % of controls failed to affect follicular B cell localization in mice at either 24 or 48 h after transfer. Localization of thymus or bursa cells in chickens was similarly unaffected by CVF pretreatment.

The possible roles of Fc and C3 receptors on migration of B lymphocytes into follicles and germinal centers were discussed.
Immunofluorescent detection of differentiation alloantigens (CA1) in the chicken
Authors: Galton Jane , Ivanyi J.
Published: February 2007

Lymphoid cell surface alloantigens were detected by a triple‐layer immunofluorescence technique. An antiserum raised against B locus‐incompatible lymphoid cells also reacted with previously undefined differentiation antigens (CA1) which segregated between B locus homozygous (B14/B14) chickens of the same strain as the antiserum donor. CAl‐positive chickens reacted with the antiserum by agglutination of red cells and staining of all peripheral lymphocytes and thymocytes but not bursal cells. Cross‐absorption experiments have demonstrated that antigens expressed by red cells, T cells (both thymic and peripheral) and B cells (peripheral only) respectively, were of distinct specificity.
Ontogeny of the antibody‐forming cell line in mice
Authors: Rosenberg Yvonne J. , Cunningham A. J.
Published: February 2007

A role for antigen in the generation of fully mature splenic type B cells has been shown. In adoptive transfer experiments, cells from bone marrow or fetal liver required a longer period to give an anti‐sheep red blood cell plaque‐forming cell (PFC) response than those from spleen. This delay was not overcome by allowing the cells a 7‐day sojourn in the irradiated host before antigen challenge. A two‐stage protocol was designed in which the in vivo generation of fully mature cells could be measured by their ability to give PFC in lipopolysaccharide‐stimulated cultures in vitro. These experiments showed that a critical factor which influences the final differentiation of bone marrow or fetal liver cells into mature, splenic type B cells is exposure to antigen.
Functional development of the interacting cells in the immune response
Authors: Russell J. L. , Golub E. S.
Published: February 2007

Neonatal splenectomy and congenital absence of the spleen were shown to be associated with lack of primary IgM antibody synthesis, deficient bone marrow‐thymus cell synergism, altered mitogen responsiveness and depressed homing patterns of thymocytes to the spleen. Using congenitally asplenic animals, altered B‐T cell cooperation was manifest at the T cell but not B cell level. This correlated with the ability of thymus cells from either congenitally asplenic or neonatally splenectomized (NSx) animals to respond to the B cell mitogen lipopolysaccharide although there were no detectable Ig+ cells present. To determine the role played by the spleen in the development of T cell function, NSx animals were given either irradiated or normal spleen grafts. Both irradiated and unirradiated grafts restored normal B‐T cooperation and normal mitogenic responses of thymus cells. However, neither type of spleen graft was successful in restoring normal homing patterns to the spleen. It is concluded that the splenic microenvironment influences T cell maturation very early in life and that only some of the effects attributable to the absence of the spleen can be reversed by the reintroduction of this tissue as a graft.
Interaction between IgE complexes and macrophages in the rat: a new mechanism of macrophage activation
Authors: Capron A. , Dessaint J. ‐P. , Joseph M. , Rousseaux Roselyne , Capron Monique , Bazin H.
Published: February 2007

In earlier studies we found that normal rat macrophages, preincubated at 37°C with the serum of syngeneic rats immune to Schistosoma mansoni, strongly adhered to S. mansoni schistosomules whereas no significant adherence was induced with serum from normal rat. Using51 chromium release assay, it now proved that immune serum‐incubated macrophages lysed the schistosomules in 18 h. Absorption experiments and ultracentrifugation of the immune serum showed that immune complexes containing specific IgE antibody against S. mansoni and soluble parasite antigens induced macrophage adherence and cytotoxicity. Using various labeling techniques, the binding of aggregated rat IgE to the macrophage surface at 37°C is evident in conditions where endocytosis is negligible. The binding of immune complexes containing IgE antibody to S. mansoni elicits dramatic ultra structural changes in the macrophage and an increase of its lysosomal enzymes together with specific lytic activity for the schistosomules. The parallel development of immune serum‐induced macrophage adherence or cytotoxicity with the level of circulating IgE antibody to the parasite in correlation with the development of immunity in the rat, suggests that this new mechanism of macrophage activation could play a role in immune effector mechanisms against S. mansoni. Therefore, IgE acts as a humoral mediator of cellular immunity.
Short Papers
Authors: Besedovsky H. , Sorkin E. , Felix D. , Haas H.
Published: February 2007

The immune system is subject to an array of identified autoregulatory processes, but immunoregulation may also have a further basis in a network of immune‐neuroendocrine interactions. Two antigens each produced an increase of more than 100 % in electrical activity of individual neurones in the ventromedial but not in the anterior nucleus of the rat hypothalamus. Animals that failed to respond to antigen manifested no increase in the firing rate. These findings constitute the first evidence for a flow of information from the activated immune system to the hypothalamus, suggesting that the brain is involved in the immune response.
Cellular events in protein‐tolerant inbred rats
Authors: Bell E. B. , Shand F. L. , Gradwell Susan
Published: February 2007

The ability of immunogens to maintain or extend a state of unresponsiveness was investigated in unbred rats using a human serum albumin (HSA) model of tolerance. Rats initially challenged with immunogen within two weeks of high or low dose tolerance induction by tolerogen (soluble HSA) remained hypore‐sponsive even a year and a half later and in some cases became less responsive following a subsequent challenge. An inhibitory effect of immunogen on escape from tolerance was formally demonstrated: in comparison with an unchallenged group, tolerant rats which received a second immunogen challenge 6 months after the first, synthesized less antibody; this antibody underwent a gradual decline in affinity after each challenge which suggested that higher avidity B cells were progressively lost. In addition, immunogen‐maintained tolerant rats (a) had demonstrable helper T cell activity among their thoracic duct lymphocytes on adoptive transfer, (b) did not produce a significant increase in antibody synthesis after receiving peripheral T cells and (c) provided no evidence that suppressor cells were playing a role. The results suggested that the mechanisms of tolerance induction by tolerogen and tolerance maintenance by immunogen are fundamentally different.
In vitro studies on H‐2‐linked unresponsiveness to synthetic polypeptides
Authors: Howie Sarah , Feldmann Marc
Published: February 2007

The in vitro production, assay and partial characterization of an extremely potent antigen‐specific T helper cell factor to poly‐L‐(Tyr, Glu)‐poly‐DL‐Ala‐poly‐L‐Lys [(T, G)‐A–L] which may be an important physiological mediator of T cell function in vivo is described. The factor has an antigen‐binding site, Ia and Ig‐like determinants on the same molecular complex. The response to (T, G)‐A‐L is under H‐2‐linked Ir gene control, some but not all low responder haplotypes will produce the factor.
Influence of molecular structure on the tolerogenicity of bacterial dextrans
Authors: Howard J. G. , Moreno C. , Hale Christine , Vicari G.
Published: February 2007

Dextran B1355 induces separate IgM responses in mice against its α(l→3) and a(l→6)‐linked glucosyl linkages. The maximum injectable dose (10 mg) produces α(l→3) immunity and α(l→6) tolerance in the BALB/c strain. The same amount will tolerize the CBA strain for both epitopes, whereas 1 mg will produce α(l→3) tolerance and α(l→6) immunity. The converse dissociation in these strains between tolerance and immunity to the two intrinsic epitopes of dextran B1355 seems, in the face of the corresponding minimum immunogenic doses, incompatible with B cell tolerance mechanisms invoking either an excess of “one nonspecific signal” or lack of a “second signal”.

A basis was sought for the exceptional resistance of BALB/c mice to α(l→3) tolerization, for dextran B1355 behaved like a typical polysaccharide antigen in the CBA strain. The induction time for α(l→3) tolerance in CBA was even shorter (<6 h) than that for α(l→6), and the unresponsive state was as stable on cell transfer as α(l→6) tolerance in either strain. Macrophage involvement in this strain difference had been previously sought but not found (Immunology 1976. 30: 221.). Although BALB/c mice are “high responders” for the α( l→3) epitope, the B cell clone did not show any superior capacity to regenerate. Indeed, the slow recovery of responsiveness to both epitopes in bone marrow‐reconstituted, irradiated mice was notably prolonged in the case of BALB/c.

PFC inhibition by oligosaccharides of the nigerose series revealed that the α(l→3) response corresponded to at least a tetrasaccharide determinant in CBA but to only a trisaccharide in BALB/c. As B cells specific for isomalto‐tetraose have a higher tolerance dose threshold than those for isomaltohexa‐ose (Immunochemistry 1977. 14: 253), it seems probable that genetic resistance of BALB/c to α(l→3) tolerance depends on recognition of a relatively small epitope which could involve instability of binding between polysaccharide and B cell receptors.
Accessory cell dependence of lectin‐induced proliferation of mouse T lymphocytes
Authors: Habu S. , Raff M. C.
Published: February 2007

Mouse lymph node cells were exposed to carbonyl iron and a magnet to remove phagocytic cells, and passed over Sephadex G‐10 and nylon wool and incubated for 12 h on plastic to remove adherent cells and their precursors. More than 99 % of the cells in this macrophage‐depleted population (which constituted 3‐5 % of the starting population) were Thy‐1+ and Ly‐1+, while less than 2 % were Ly‐2+. These cells usually did not synthesize detectable amounts of DNA when cultured with concanavalin A and responded poorly to phytohemagglutinin. These proliferative responses were completely reconstituted by small numbers of syngeneic or allogeneic peritoneal cells, purified peritoneal macrophages or cells from tertiary cultures of mouse embryo ‘fibroblasts’, but not by 3T3 cells, P815 mastocytoma cells or Nulli SCC‐1 embryonal carcinoma cells, or by 2‐mercaptoethanol. The reconstituting peritoneal cells were Thy‐1−, Ia+ and present in nu/nu mice; although they had to be alive to reconstitute, they did not have to divide. These results are consistent with the hypothesis that T cell proliferation induced by lectins, like that induced by antigens, may involve the dual recognition of stimulating ligand in association with major histocompatibility complex (la) determinants.
Are “hidden” genes for immunoglobulin allotypes of rabbit heavy and light chains expressed upon hyper‐immunization?
Authors: Mage Rose G. , Rejnek J. , Young‐Cooper Glendowlyn O. , Alexander C.
Published: February 2007

The question of whether genes for some Ig‐allotypic forms may be “hidden” in the genome was investigated by hyperimmunization of 36 allotypically pedigreed rabbits with a vaccine of Micrococcus luteus (Micrococcus lysodeikticus). Since Strosberg et al. (J. Immunol 1974.113: 1313) have reported that such hyperimmunization elicited expression of a third “allele” at two different loci (a2 and b6 in a rabbit whose original phenotype was ala3b4b5), we wished to determine whether their immunization protocol would reproducibly elicit expression of “hidden” allotypes. None of the 36 immunized rabbits developed elevated expression of an unexpected allotype during the 7‐38 weeks of immunization and bleeding. However, we did observe elevated expression of unusual variable regions. In particular, a cross‐reaction between some VH region gene products produced by al rabbits, and the majority of VH products of a2 rabbits was detected with anti‐a2 antisera made in a3a3 but not in a1a1 or a1a3 rabbits. There is a small percentage of Ig molecules in a1a1 rabbits whose V regions contain an antigenic determinant also present on most or all a2 molecules of rabbits. A similar determinant is also found on Ig of related genera (Lepus and Sylvilagus) Expression of this population was elevated during immunization of an a1a3 rabbit with Micrococcus. In immunodiffusion, a reaction of partial identity was observed. In hemagglutination inhibition, the reaction of a3 anti‐a2 with homologous a2 was not inhibitable by the cross‐reacting component. Anti‐a2 antisera made in a3 rabbits could be depleted of cross‐reactive antibody by absorption with insolubilized sera from normal al rabbits but not by insolubilized a3 sera. Radioautography of isoelectric focusing plates overlayed with a3 anti‐a2 antibodies which had been affinity‐purified and radiolabeled, revealed distinct spectrotypes in sera from al rabbits that carried the cross‐reacting VH determinants.
Failure of T cells specific for strong histocompatibility antigens to cooperate with B cells for a humoral response
Authors: Dennett G. , Rose Margaret De , Allen Roberta Stauder
Published: February 2007

Thymus‐derived lymphocytes (T cells) selected for reactivity to strong histocompatibility antigens over a period of one to twelve months in vitro were tested for their ability to cooperate with bone marrow‐derived lymphocytes (B cells) for a humoral response. If cultured with normal syngeneic or allogeneic spleen cells and sheep erythrocytes (SRBC) as immunogen, inhibition of the anti‐SRBC response was observed. Similarly, in T cell‐free spleen cells the alloreactive T cells did not stimulate a humoral response, indicating that they cannot exert cooperative activity on B cells. Since it was possible that the alloreactive T cells may cooperate with B cells in a humoral response to immunogens carrying histocompatibility antigens, hapten‐coupled tumor cells were also used as immunogen. Though it is demonstrated that the alloreactive T cells do recognize the tumor cell'immunogen, no stimulation of the B cells for a humoral response against the tumor cell is observed. This result, as well as the finding that the antigenic requirements for T helper cell priming and cell proliferation of the alloreactive T cells are different, suggests that these alloreactive T cells and helper T cells belong to different T cell subsets.
Distinct properties of Thy‐1 antibodies elicited in rats by immunization with mouse brain
Authors: Rabinowitz Ruth , Sharav Y. , Schlesinger M.
Published: February 2007

Rats are known to possess antigenic determinants related to the Thy‐1.1 allele. Immunization of rats with brain homogenates from mice carrying either the Thy‐1.1 or the Thy‐1.2 alleles resulted in the production of antisera which were cytotoxic for thymus cells of both strains of mice.

Lymph node, spleen and cortisone‐resistant thymus cells were refractory to the cytotoxic effect of rat anti‐mouse brain sera. Peripheral lymphocytes were fully capable of absorbing the cytotoxic activity of the sera on thymus cells, although the concentration of the antigen on their cell surface was considerably less than on thymus cells. Blocking experiments with alio‐ and xenoantisera to Thy‐1 antigens suggested that the antigen detected by rat anti‐mouse brain sera is related to the Thy‐1 system.

The Thy‐1 specificity detected by rat antisera seems to differ from previously described Thy‐1 antigens in that it attains a high concentration on thymus cells but is relatively deficient in its expression on peripheral T cells.
Restriction in the immune response to flagellar proteins in inbred mice
Authors: Smith A. M. , Slack J. , Potter M.
Published: February 2007

Anti‐idiotypic sera prepared in both AL/N mice and rabbits identify specificities common t o the IgA MOPC 467 myeloma protein and day‐7 affinityabsorbed antibodies t o Salmonella milwaukee polymerized flagellin (S.mi1 POL) raised in BALB/c and C57BL/Ka mice. Isoelectric focusing (IEF) of reduced and alkylated BALB/c anti‐S.mil‐POL gave a banding pattern of L and H‐chains identical to MOPC 467. C57BL/Ka anti‐S.mi1‐POL had a similar Lchain pattern but a different H‐chain pattern. Both BALB/c and C57BL/Ka contain predominantly IgA. The IEF patterns in the two strains are consistent with a monoclonal response at day 7.
Lymphocyte membrane immunoglobulins: similarities between human IgD and mouse IgD‐like molecules
Authors: Sitia R. , Corte G. , Ferrarini M. , Bargellesi A.
Published: February 2007

131I‐labeled IgD‐like molecules extracted from the membrane of mouse spleen, and lymph node cells and their constitutive chains have been characterized by sodium dodecyl sulfate polyacrylamide slab gel electrophoresis (SDS‐PAGE) followed by radioautography. Unreduced mouse IgD‐like molecules concentrated in two definite bands (IgD1 and IgD2). IgD, migrated slightly ahead of 131I‐labeled mouse membrane IgM and displayed a mobility very similar to that of 131I‐labeled IgD extracted from the membrane of human tonsil cells. IgD2 migrated faster than both IgD1 and human membrane IgD (mIgD), but slower than 14C‐labeled mouse IgG2 b used as marker. The different mobility of IgD1 and IgD2 was due to difference in size of their respective H‐chains (δ1 and δ2), as shown by SDS‐PAGE analysis of the two molecules after reduction. Mol.wt. determination of IgD1, IgD2 and of the corresponding constitutive chains are consistent with an H2L2 structure. IgD1 and IgD2 were partially replaced following prolonged dialysis by molecules with a SDS‐PAGE mobility consistent with an HL structure, IgD3. In contrast to that found for spleen and lymph node, IgD1 only was detected on the surface of bone marrow cells.

Immunofluorescence experiments have shown that while the majority of mouse lymph node or spleen cells bear IgM and IgD, IgM was found to be the predominant Ig class on the surface of bone marrow cells, although a certain number of IgD‐IgM and a few IgD‐positive cells were found.

Experiments where mouse lymphocytes have been treated with pronase have indicated that, in analogy with mlgD of primates, mouse IgD‐like molecules are very labile and can be removed from the cell surface by very mild proteolytic treatment.