bluuebunny/crossref_metadata_2025 huggingface dataset:
Confirmation of the assignment of genes for human immunoglobulin heavy chains to chromosome 14 by analysis of Ig synthesis by man‐mouse hybridomas
Authors: Smith Moyra , Krinsky Adrienne , Arredondo‐Vega Francisco , Wang Ai‐Lan , Hirschhorn Kurt
Published: February 2007

Hybridomas were produced by fusing the NS1 mouse myeloma line, which does not produce mouse heavy chain Ig, with human peripheral B lymphocytes from a normal individual. Two vigorously growing colonies from this fusion were found to secrete human Ig heavy chains and were recloned. Two secondary clones, which secreted human chains, were again recloned. Among the tertiary clones, two were identified which produced intracellular human Ig chains, but did not secrete immunoglobulin. These tertiary clones were recloned, generating 6 quaternary clones which failed to produce human Ig heavy chains, and 15 quaternary clones which produced intracellular Ig chains. Hybrid clones from each successive subcloning were examined for their human chromosomal content and only those clones which were found to be individually chromosomally distinct, a total of 56 clones in all, were used to analyze the segregation of human chromosomes and human Ig heavy chain synthesis. Results of this study indicate concordant segregation of human Ig heavy chain synthesis and chromosome 14. These studies therefore confirm the previous assignment by C. M. Croce et al. (Proc. Natl. Acad. Sci. USA 1979. 76: 3416) of the genes for human Ig heavy chains to chromosome 14.
Lectin‐binding patterns of small lymphocytes in bone marrow, thymus and spleen: demonstration of lymphocyte subsets by quantitative radioautography
Authors: Saveriano Nellina , Drinnan Michael , Santer Vivien , Osmond Dennis G.
Published: February 2007

Cells from mouse bone marrow, thymus and spleen were exposed to 125I‐labeled concanavalin A (Con A), Lens culinaris lectin (LCL), soybean agglutinin (SBA), Helix pomatia agglutinin (HPA), phytohemagglutinin‐P (PHA‐P), peanut agglutinin (PNA), or wheat germ agglutinin (WGA) in a range of concentrations and examined radioautographically. Small lymphocytes in the three organs differed in the minimal concentration of each lectin which gave detectable surface labeling, while at optimal lectin concentrations, their labeling intensity profiles differed markedly. Inhibition by sugars demonstrated the labeling specificity. Major populations of bone marrow small lymphocytes bound WGA strongly, while Con A, SBA, HPA, PHA‐P and LCL were bound only weakly, and PNA binding was lacking. Most thymus cells bound Con A, SBA, HPA, PHA‐P and PNA strongly, WGA and LCL weakly. Subsets of bone marrow and thymus small lymphocytes differed from the major populations in their lectin‐binding intensities. Spleen small lymphocytes were heterogeneous in the binding of each lectin. However, a major population bound LCL exceptionally strongly, while few cells bound PNA. Using a panel of lectins under standardized conditions, these studies show distinctive lectin‐binding patterns for small lymphocytes in the bone marrow, thymus and spleen, respectively. Major and minor cell populations are distinguishable in each organ, providing an approach to discriminating lymphocyte lineages, subtypes and differentiation stages.
Regulation of delayed‐type hypersensitivity. VII. The role of I‐J subregion gene products in the inhibition of delayed‐type hypersensitivity to major histocompatibility antigens by specific suppressor T cells
Authors: Liew Foo Y.
Published: February 2007

Suppressor T cells for delayed‐type hypersensitivity (DTH) to alloantigens are induced by injecting mice intravenously with a high dose of X‐irradiated allogeneic cells. Using the same protocol, suppression of DTH directed against H‐2 subregion products could also be induced, provided that the H‐2 incompatibility between the cells used for the induction of suppression and the recipients includes the I‐J subregion genes. Thus, the I‐J subregion difference is both necessary and sufficient for the induction of suppression of DTH to the whole or part of the H‐2 gene products. The suppression appears to be mediated by antigen‐specific suppressor T cells which recognize the allo‐I‐J molecules and are able to suppress the DTH response to other H‐2 subregion gene products in an associative recognition manner. T cells from (B10 × BALB/c)F1 mice suppressively primed against B10.A(5R) cells (directed against JkEk antigens), when adoptively transferred to normal syngeneic recipients, were capable of suppressing the hosts' DTH response to B10.A(4R) cells (KkAk antigens) when the recipients were challenged with [B10.A(4R) × B10.A(5R)]F1 cells (KkAk × JkEk). The recipients express normal DTH reactivity to B10.A(4R) cells when challenged with a mixture of B10.A(4R) and B10.A(5R) cells (KkAk + JkEk). These results provide direct evidence that when functioning as alloantigens, the I‐J determinants preferentially induce suppressor T cells which specifically impair the immune response to the I‐J molecules as well as other H‐2 gene products if they are physically associated with the I‐J determinants. The role of I‐J subregions as the suppressor genes is discussed in terms of the possible application in transplantation immunity and the host's defence against infectious diseases.
Primary antibody responses to hapten‐modified syngeneic cells: exceptional immunogenicity of erythrocytes
Authors: Nakashima Izumi , Takashi Munehisa , Nagase Fumihiko , Kato Nobuo
Published: February 2007

Intravenous injection of fluorescein isothiocyanate‐modified syngeneic spleen cells (FITC‐SSC) into mice induced T cell‐independent, anti‐hapten plaque‐forming cell responses. In contrast to the high immunogenicity of FITC‐coupled SSC or bone marrow cells, thymus, lymph node or peritoneal exudate cells were poorly immunogenic. Further analysis showed that FITC‐syngeneic peripheral blood red cells were as immunogenic as FITC‐SSC containing a similar number of red cells. The immunogenicity of the red cells was confirmed by treatment of FITC‐SSC with 0.83% ammonium chloride before sensitization with FITC. This procedure almost totally abolished the immunogenicity regardless of the concentration of hapten with which they were sensitized. In addition, heat treatment or fixation with glutaraldehyde destroyed the immunogenicity of FITC‐SSC.
Immunoregulatory circuits which modulate responsiveness to suppressor cell signals: characterization of an effector cell in the contrasuppressor circuit
Authors: Green Douglas R. , Eardley Diane D. , Kimura Art , Murphy Donal B. , Yamauchi Katsumi , Gershon Richard K.
Published: February 2007

Spleen cells from neonatal animals, placed in culture for 6 days spontaneously develop the ability to block the activity of suppressor T cells, a phenomenon that is referred to as contrasuppression. The effector cell which is derived from the interactions among the cells which comprise a contrasuppressor “circuit” is an Ly‐1 T cell. It can be separated from Ly‐1 helper cells by three criteria other than function: its generation is dependent on Ly‐2+ cells, it is I‐J+, and it sticks to the Vicia villosa lectin. Those cells which deliver help to B cells under the experimental conditions studied are not dependent on Ly‐2+ cells for generation and neither express determinants that our anti‐I‐J antisera recognize nor stick to V. villosa.

The mechanism by which these Ly‐1 contrasuppressor cells function was elucidated by adding them to “intermediate cultures” containing activated Ly‐2 suppressor cells and in vivo immunized Ly‐1.1‐congenic helper cells. After 48 h in these intermediate cultures, the neonatal Ly‐1.2 contrasuppressor cells and the Ly‐2 suppressor cells were removed by treatment with the appropriate antiserum plus complement. The remaining activity of the in vivo generated Ly‐1.1 helper cells was assayed in fresh cultures of B cells. The contrasuppressor cells not only diminished suppression of the Ly‐1 helper cells by the Ly‐2 suppressor cells in the intermediate culture, but actually conferred a state of relative resistance to suppression upon the helper cells. This state persisted after the contrasuppressor cells were removed. Why such a cellular circuit, which confers resistance to suppression, might be beneficial to neonatal mice and how considering its attributes might help explain some immunological paradoxes is the subject of discussion.
A subset of human natural killer cells isolated and characterized by monoclonal antibodies
Authors: Lohmeyer Jürgen , Rieber Peter , Feucht Helmut , Johnson Judith , Hadam Martin , Riethmüller Gert
Published: February 2007

Monoclonal antibodies were induced against leukemic T cells from a patient with chronic lymphocytic leukemia exhibiting natural killer (NK) activity. Two antibodies, termed T811 and M522, reacted by indirect immunofluorescence with distinct subpopulations of normal human mononuclear blood cells. The antibody T811 defines a surface antigen which is restricted to a subset of the T cell lineage. The antigen recognized by the second antibody, M522, is expressed on monocytes and polymor‐phonuclear leukocytes and, in addition, on 9–17% of nonadherent peripheral blood leukocytes (NAL). It is shown that the total NK activity of NAL is confined to the subset of cells expressing the M522‐defined antigen. Moreover, the portion of NK cytotoxicity associated with T lymphocytes is mediated by a subpopulation which is characterized by the simultaneous expression of the T811‐ and the M522‐defined antigens. This population comprises about 4% of NAL and could be isolated to a purity of > 85%.
Heterogeneity of complement receptor expression on surface immunoglobulin‐bearing cells from neonatal and adult mice
Authors: Cossman Jeffrey , Richman Jill A. , Mond James J.
Published: February 2007

The ontogeny of acquisition of complement receptors (CR) on splenic B lymphocytes from mice of varying ages was examined. Reagents used for the identification of CR included antibody‐ and complement‐coated erythrocytes (EAC), bacteria (BAC) and bacteria treated with complement alone (BC). When whole mouse serum was used as the source of Complement both EAC and BAC failed to bind to human erythrocytes (C3b receptor‐negative). showed binding to Raji and Daudi cells (C3d receptor) and formed rosettes with human neutrophils (C3bi receptor). Therefore these reagents bore C3d and C3bi, but not intact C3b. Although EAC and BAC detected nearly equal percentages of CR lymphocytes in adult mice, BAC bound to a higher percentage of neonatal lymphocytes (8‐1296) than did EAC (1‐395). The ability of BAC to detect EAC‐negative lymphocytes among neonatal spleen lymphocytes appeared to be due to the increased sensitivity of this bacterial reagent for binding to CR. Further evidence of this enhanced sensitivity was that BAC were less inhibitable than EAC by soluble antigen‐antibody‐complement complexes.
Idiotype regulation: evidence for the involvement of Igh‐C‐restricted T cells in the M‐460 idiotype suppressive pathway
Authors: Juy Dominique , Primi Daniélé , And Pierre Sanchez , Cazenave Pierred‐André
Published: February 2007

Allotypic restriction of idiotype suppression has been shown in several idiotypic systems. It has also been demonstrated that naive BALB/c mice contain naturally occurring suppressor T cells capable of inhibiting the M‐460 idiotype expressed on BALB/c B cells, and that T cells from allotype‐congenic mice have no effect on this expression. Since we have previously shown that upon polyclonal activation B cells of all mice tested are capable of secreting M‐460‐positive anti‐2,4,6‐trinitrophenyl (TNP) antibodies, we postulated that idiotype suppressor cells may recognize idiotypes in conjugation with products of the Igh loci. In the present study we tested this hypothesis. The data clearly showed that regardless of their allotypic haplotype all strains of mice do possess suppressor cells capable of recognizing the M‐460 idiotype. However, mixing experiments indicated that the functional potential of these suppressor cells can only be expressed when T and B lymphocytes come from allotype‐matched animals. Efficient suppression in those cultures containing allotype‐matched but incompatible B and T cells at the I‐J region of the H‐2 locus could be detected.

Finally, using allotypic recombinant strains of mice, we found evidence that the restrictive elements in idiotypic suppression are the product of genes mapping in the Igh‐C locus, or closely linked to it.
Inhibition of murine T cell‐mediated cytolysis and T cell proliferation by a rat monoclonal antibody immunoprecipitating two lymphoid cell surface polypeptides of 94000 and 180000 molecular weight
Authors: Pierres Michel , Goridis Christo , Golstein Pierre
Published: February 2007

The monoclonal antibody methodology was used to identify membrane structures involved in T cell functions. To optimize chances to produce and detect relevant antibodies, a xenogeneic sensitization protocol was utilized and hybridoma supernatants were screened, on functional rather than structural grounds, for their ability to inhibit a given function. The test function was T cell‐mediated cytolysis. Mouse cytolytic anti‐allogeneic cell populations were used to sensitize a rat, the spleen cells of which were fused to produce hybridomas; the supernatants of the latter were screened for their ability to inhibit mouse T cell‐mediated cytolysis in vitro. Several inhibitory antibodies were obtained, one of which, H35‐89.9 monoclonal antibody, was studied in more detail. It inhibited specific and concanavalin A (Con A)‐mediated cytolysis by T cells, by acting on the effector cells. It reversibly inhibited soluble antigen‐, alloantigen and Con A‐induced T cell proliferation (but not LPS‐induced B cell proliferation), after the production of interleukin 2, by acting on the responder cells. It also had a desagglutinating effect on Con A and LPS blasts and on EL4 cells. It immunoprecipitated from thymocyte membrane preparations two structures of 94000 and 180000 apparent molecular weight, and recognized cell surface determinants on both T and B lymphocytes.

Our findings suggest that several antibodies directed against distinct effector cell membrane structures inhibit cytolysis. The case of H35‐89.9 monoclonal antibody, which exerts multiple functional effects and immunoprecipitates two membrane polypeptides, raises the problem of the various possible relationships between these structures and functions.
Interactions between primed and unprimed cells in the regulation of in vitro antibody responses. I. Role of “plasma cells” as inducers of suppression
Authors: Calkins Catherine E.
Published: February 2007

Specific immune suppression has been shown to be activated in culture by the interaction of primed and unprimed T cell subsets. The primed cell involved is found 8 days after immunization in spleen but not in lymph node or thymus cell populations. When the primed spleen cells were fractionated by nylon wool passage or anti‐Thy‐1 plus complement (C) treatment, prior to culture with unseparated unprimed cells, suppression was detectable only with primed B cells present in the co‐cultures. Treatment of the primed spleen cells with anti‐PC. 1 (an antiserum specific for plasma cells) plus C eliminated their ability to cooperate with either unseparated or T cell‐enriched populations of unprimed cells in suppressing the antibody response of the co‐cultures. These data are consistent with the hypothesis that antibody‐secreting plasma cells activate suppressor T cell precursors in cell populations not previously exposed to antigen.
Epstein‐Barr virus (EBV) receptor implantation onto human B lymphocytes changes immunoglobulin secretion patterns induced by EBV infection
Authors: Tsukuda Koji , Volsky David J. , Shapiro Ilya M. , Klein George
Published: February 2007

Mosaic membrane vesicles containing both Epstein‐Barr virus (EBV) receptors and Sendai virus envelope proteins were allowed to form by the previously described membrane solubilization and co‐reconstitution technique. The vesicles were allowed to fuse with the membranes of normal human B lymphocytes, whereafter the cells were infected with transforming EBV (B95‐8 substrain). Compared to similarly infected but otherwise unmanipulated cells, the receptor‐implanted lymphocytes responded with a larger number of EBV‐determined nuclear antigen positive and immunoglobulin‐secreting plaque‐forming cells (PFC). Moreover, there was a clear increase of the IgG/IgM PFC ratio in the receptor‐implanted B lymphocytes. These results show that not all human B lymphocytes that can potentially be activated by EBV express functional EBV receptors. B lymphocytes programmed to secrete IgG appear to be more defective in this respect than IgM secretors.
Differential effects of glucocorticosteroids on the functions of subpopulations of helper T lymphocytes
Authors: Bradley Linda M. , Mishell Robert I.
Published: February 2007

The in vitro effects of dexamethasone on the activities of Th1 and Th2 helper cell subpopulations were examined in secondary (IgG) responses to hapten‐carrier conjugates under conditions where the selective or dominant expression of their individual activities could be observed. In the induction of IgG anti‐hapten responses, carrier‐primed Th1 cells cooperate with hapten‐primed B cells by linked recognition of antigen, while carrier‐primed Th2 cells cooperate with hapten‐specific B cells by unlinked recognition of antigen. The function of carrier‐primed Th2 cells was resistant to inactivation by dexamethasone. In contrast, the function of carrier‐primed Th2 cells was abolished in the presence of pharmacologic concentrations of the steroid. The differential effects of dexamethosone on the activities of the two subpopulations of helper T cells could not be attributed to selective inhibition of a subpopulation of B cells which cooperates with Th2 cells.
The expression and functional involvement of nuclease‐specific idiotype on nuclease‐primed helper T cells
Authors: Nadler Paul I. , Miller Geraldine G. , Sachs David H. , Hodes Richard J.
Published: February 2007

The expression and functional significance of idiotypic determinants on antigen‐specific helper T (Th) cell populations for responses to Staphylococcal nuclease (Nase) were evaluated in an in vitro antibody response system. Trinitrophenyl (TNP)‐specific plaque‐forming cell responses to TNP‐conjugates of Nase (TNP‐Nase) were shown to require the cooperation of Nase‐primed Th cells as well as unprimed B and accessory cells. The expression on these antigen‐primed Th cells of idiotypic determinants cross‐reactive with those on anti‐Nase antibodies was demonstrated by the specific elimination of Th cells for TNP‐Nase by treatment with affinity‐purified anti‐idiotypic antibodies plus complement. The susceptibility of Nase‐primed Th cells to elimination by such treatment was specific in that anti‐idiotypic antibodies affected Th cells only from strains normally expressing the same (or a cross‐reactive) idiotype on anti‐Nase antibodies. A functional role of the idiotypes expressed on Nase‐primed Th cells was suggested by the fact that anti‐idiotypic antibody present throughout the period of culture, in the absence of complement, suppressed responses to TNP‐Nase in an antigen‐ and strain‐specific manner. It was further shown, by cell mixing experiments, that this inhibition appeared to occur at the level of the Th cells and was not dependent on the strain of origin of the B cells. Thus, antigen‐specific Nase‐primed Th cells express strain‐specific idiotypic determinants cross‐reactive with, or identical to, those of anti‐Nase antibodies. These cell surface idiotypic determinants appear to be functionally involved in the activity of Th cells for the induction of antibody responses to TNP‐Nase in vitro.
Immune response against the T‐independent antigen α(1→3)dextran. I. Demonstration of an unexpected IgG response of athymic and germ‐free‐raised euthymic BALB/c mice
Authors: Schuler Walter , Lehle Georg , Weiler Eberhardt , Kölsch Eckehart
Published: February 2007

The primary antibody response in BALB/c mice to the T‐independent bacterial antigen dextran B1355S [α(l → 3)dextran] (Dex) was studied by means of isoelectric focusing, hemagglutination and immunodiffusion techniques. In response to a single immunization with 10 kg Dex all mice produce specific IgM antibodies. In addition, about 30% of conventionally raised BALB/c and BALB/c nu/+ mice, but 95% of germ‐free (GF)‐raised normal BALB/c and 100% of athymic BALB/c nu/nu mice produce specific IgG class anti‐Dex antibodies. These antibodies include all IgG subclasses, carry predominantly the λ light chain and the cross‐reactive J558 idiotype and are specific for the α(1 → 3)glucosidic linkage.

As compared to athymic and GF‐raised mice, conventionally raised mice exhibit only a weak IgG response. The pronounced IgG production of GF‐raised mice was not altered when adult mice were removed from their GF environment and housed under conventional conditions for several weeks prior to immunization with Dex. Reconstitution with isolated splenic T cells from conventionally raised, unprimed BALB/c mice reduces the remarkable capacity of BALB/c nu/nu mice to produce IgG anti‐Dex antibodies.

These findings suggest that the reduced capacity of conventionally raised BALB/c mice to mount an IgG response to the T‐independent antigen Dex is due to a T cell‐mediated suppressive mechanism which is neonatally induced by contact with environmental, i. e. bacterial, antigens.
Functionally different subpopulations of mouse macrophages recognized by monoclonal antibodies
Authors: And Deming Sun , Lohmann‐Matthes Marie‐Luise
Published: February 2007

Four rat anti‐mouse macrophage monoclonal antibodies are described. Three of them are highly specific for macrophages, and one cross‐reacts with granulocytes. All 4 antibodies do not react with membrane antigens shared by all macrophages, but with antigens present only on subpopulations of 20‐50% of the cells. All antibodies are directly or indirectly cytotoxic for macrophages. The subpopulations defined by these antibodies can be correlated with certain macrophage functions. Thus, antibody M43 eliminates macrophages that are activated by lymphokine to cytotoxicity. Antibodies M43 and M57 eliminate macrophages that kill antibody‐coated tumor targets, and clone 102 (strictly macrophage‐specific) eliminates natural killer cells. Only M143, reacting with 10‐30% of macrophages, has not yet been correlated with any function. With the use of these antibodies, cells of the macrophage lineage with specific functions can be recognized and eliminated from a given population.
Heterogeneity of soluble T cell products I. Precursor frequency and correlation analysis of cytotoxic and immune interferon (IFN‐γ)‐producing spleen cells in the mouse
Authors: Krammer Peter H. , Marcucci Fabrizio , Waller Michael , Kirchner Holger
Published: February 2007

In this study, the precursor frequency, relationship and activity of murine splenic cytotoxic and immune interferon (IFN‐γ)‐producing cells has been determined. C57BL/6 spleen cells were activated by concanavalin A (Con A) and subsequently grown in microcultures under limiting dilution conditions. The progeny of cells plated in microcultures was divided and tested for (a) total cytotoxic activity on EL4 (H‐2b) tumor target cells in the presence of Con A to nonspecifically attach the killer to the target cells, and (b) the quantity of IFN‐γ released by Con A stimulation.

Cytotoxic T lymphocytes and IFN‐γ producing cells were present in Con A‐activated C57BLi6 spleen cells at a high frequency of approximately 1 out of 3 and 1 out of 2 cells, respectively. IFN‐γ could be released from both noncytotoxic and a large fraction of cytotoxic T cells and the cytotoxic activity was not necessarily associated with IFN‐γ release. In a few selected cultures with a progeny of cells plated at a low cell number (up to 10/well) very high IFN‐γ titers (> 10000 U/ml) could be found. These results provide the first frequency estimate of IFN‐producing cells and are discussed with respect to the physiological role of IFN‐γ release from T cells.
Serological analysis of B6.C‐H‐2bm12 (I‐A mutant)
Authors: Sandrin Mauro S. , McKenzie Ian F. C. , Melvold Roger W. , Hämmerling Günter J.
Published: February 2007

The B6.C‐H‐2bm12 has been examined serologically with a new set of reagents and several complementation studies were performed to determine the extent of the mutation. The results show that: (a) the mutation has also affected the site(s) bound by xenogeneic anti‐Ia antibodies; (b) the IJb region was not affected; (c) complementation studies with stains bearing a, b, d, k and s haplotypes did not complement bm12 for the expression of the lost I‐Ab specificities, suggesting a structural (rather than regulatory) gene alteration in bm12; (d) H‐2 haplotypes b and bm12 could complement d to establish the Ia.22 specificity, indicating that Ia‐1 and Ac are separate genes in the I‐A subregion In addition, an antibody to the gained specificity on bm12 is described.
An immunoglobulin V gene polymorphism in the rat
Authors: Pelkonen Jukka , Binz Hans , Laukola Ulla , Günther Eberhard , Mäkelä Olli
Published: February 2007

Anti‐phenyloxazolone (phOx) antibodies of different AVN rats (primary response) share several isoelectric focusing bands. These bands were not shared by antibodies of some other rat strains, including DA. An anti‐idiotype reagent was prepared (in rabbits) that bound radioactive anti‐phOx antibodies of AVN rats but not normal AVN immunoglobulin. This binding was strongly inhibited by AVN anti‐phOx anti‐sera, but not by AVN anti‐BOC‐p‐azobenzene arsonate‐tyrosine antisera or DA anti‐phOx antisera. Anti‐phOx antisera of (AVN x D A)F1 rats were also strongly inhibitory indicating the presence of the idiotype (Ox‐r1). Antisera of backcross rats (AVN x DA) x DA either resembled F1 hybrid sera (31 rats) or DA sera (23 rats). The data suggest that the presence of idiotype Ox‐r1 is controlled by one gene, or genes linked to each other. The gene(s) is not linked to the Ig kappa chain locus. It may be a V gene of the Ig H chain.
Monoclonal antibodies to human erythrocytes
Authors: Anstee David J. , Edwards Paul A. W.
Published: February 2007

Eight monoclonal antibodies from mouse hybridomas raised to normal human erythrocytes were tested with a panel of null‐type erythrocytes, enzyme‐treated normal cells, and by inhibition with human erythrocyte sialoglycoproteins. Two antibodies reacted poorly or not at all with RhNULL cells. These antibodies are of considerable interest since it may be possible to use them to elucidate the chemical nature of the antigens of the Rhesus blood group system. Four other antibodies were inhibited by sialoglycopfotein preparations. The antigens recognized were, respectively, two different determinants on the major sialoglycoprotein α (glycophorin A) and one determinant which is probably common to sialoglycoproteins α and δ (glycophorins A and B). Another antibody had anti‐Wrb specificity. One of these antibodies is of considerable potential value for the further characterization of erythrocyte sialoglycoproteins.
Induction and augmentation of mitogen‐induced immune interferon production in human peripheral blood lymphocytes by Nα‐desacetylthymosin αl
Authors: Svedersky Lloyd P. , Hui Anna , May Laurie , McKay Patrick , Stebbing Nowell
Published: February 2007

Treatment of human peripheral blood lymphocytes with cloned Nα‐desacetylthymosin α1 induced interferon production. The kinetics is similar to that of mitogen‐induced interferon induction. Nα‐desacetylthymosin α1, in combination with mitogen, augments the amount of interferon produced. This interferon is immune interferon (IFN‐γ) as determined by sensitivity to pH 2, lack of neutralization by antibodies to IFN‐α or IFN‐β and absence of activity on MDBK cells. Although the mechanism of induction of IFN‐γ by Nα‐desacetylthymosin α1 is unclear, this compound is not mitogenic at concentrations causing IFN‐γ production. These results indicate that thymic factors may also participate in the regulation of IFN‐γ production.
Demonstration of muramyl dipeptide (MDP)‐induced T suppressor cells responsible for MDP immunosuppressive activity
Authors: Leclerc Claude , Bourgeois Edith , Chedid Louis
Published: February 2007

Muramyl dipeptide (MDP), a synthetic immunostimulant, has been previously shown to increase or decrease the humoral and cellular immune responses, depending upon the experimental conditions used. In the present study we have investigated the mechanisms of MDP‐induced immunosuppression. After repeated injections of high dosages of MDP in vivo, both adherent and B cell‐enriched cell populations from MDP‐treated mice were able to collaborate with normal complementary populations. In contrast, T cell‐enriched populations exhibited suppressive activity which could be removed by treatment with anti‐Thy‐1.2 antiserum and complement. These results clearly indicate that MDP‐induced immunosuppression is mediated by T cells.
Inhibition of alternative pathway factor D by factor B ‐related synthetic hexapeptides
Authors: Lesavre Philippe , Guillard Marie‐Hélène , Halbwachs‐Mecarelli Lise
Published: February 2007

Hexapeptides mimicking the partial amino acid sequence of factor B surrounding the bond that is cleaved by factor D have been synthesized. These peptides have been assessed for their ability to inhibit factor D enzymatic activity and for their susceptibility to serine proteases. The synthetic peptides were cleaved by bovine trypsin and Cls but not by α‐thrombin and factor D. The peptides inhibited factor B cleavage and fluid‐phase or cell‐bound alternative pathway C3 convertase activation by factor D. Altogether, these results suggest that peptides analogous to factor B specifically inhibit factor D enzymatic activity. Thus, they constitute an interesting tool for study of alternative pathway activation and can be of use when attempting to manipulate this pathway, since factor D is an essential component for alternative pathway initiation and amplification.
The biochemical genetics of TL antigens on mouse thymocytes
Authors: Michaelson James , Tung Jwu‐Sheng , Flaherty Lorraine , Hämmerling Ulrich , Bushkin Yuri
Published: February 2007

Molecules bearing thymus leukemia (TL) alloantigen were isolated by immuno‐precipitation from detergent‐solubilized thymocyte lysates. Antisera used included monoclonal antibodies (anti‐TL. M1, anti‐TL.m2, anti‐TL.m3), monospecific anti‐TL.5 alloantisera and multispecific anti‐TL.1,2,3,5 antiserum. Apparently, each of these reagents immunoprecipitates the same single 45 000 molecular weight Tla gene product as shown by identity on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), isoelectric focusing and by sequential precipitation studies. Allelic TL molecules, coded by the Tlaa and Tlad genes, were shown to be distinguishable by SDS‐PAGE, and tryptic peptide mapping experiments. Both allelic TL molecules could be isolated from thymocytes of (Tlaa x Tlad)F1 mice. These results suggest that, at least for the Tlaa‐Tlad allelic differences, the polymorphism and antigenicity of TL is determined by variation in amino acid composition.
Hapten‐specific responses to the phenyltrimethylamino hapten. II. Regulation of delayed‐type hypersensitivity by genetically restricted, anti‐idiotypic suppressor T cells induced by the monovalent antigen L‐tyrosine‐p‐azo‐phenyltrimethylammonium
Authors: Jayaraman Sundararajan , Bellone Clifford J.
Published: February 2007

Inoculation of A/J mice with the synthetic monovalent antigen, L‐tyrosine‐p azophenyltrimethylammonium [tyr(TMA)] results in the formation of idiotype‐specific suppressor T cells (Ts) which exclusively shut down clones of B cells that bear a dominant cross‐reactive idiotype (CRI) associated with anti‐TMA antibodies (J. Exp. Med. 1980.251: 528). It was of interest to find out whether this same population would also suppress T cell‐mediated immunity specific for the TMA ligand. Accordingly, the tyr(TMA)‐induced Ts population was tested for its ability to modulate delayed‐type hypersensitivity (DTH) reactions specific for TMA.

A/J mice were primed with tyr(TMA) in adjuvant and 6‐7 weeks later spleen cells were tested for suppressor activity. Transfer of the tyr(TMA) immune population 24 h prior to priming, or at any other time point before challenge, resulted in a significant suppression of the response. This suppression, both induction phase as well as effector phase, is mediated by T cells since treatment of the splenic population with anti‐Thy‐1 plus complement before transfer eliminates the suppressor activity. The suppressor activity is antigen‐specific, since 5 x 107 spleen cells which markedly suppress TMA DTH have no effect on contact sensitivity to dinitrofluorobenzene. Binding experiments in petri dishes coated with CRI‐bearing anti‐TMA antibodies indicate that the majority of the Ts cells have specificity for the CRI and not for the antigen (TMA). Studies using serological reagents specific for different cell surface antigens indicate that the idiotype‐specific Ts bear the I‐J subregion‐encoded surface antigen(s) as well as the Lyt‐2+ phenotype. Transfer experiments utilizing appropriate strains of mice demonstrated that the Ts were both H‐2‐ and Igh‐V‐restricted. Finally, a cell‐free preparation obtained by sonicating the tyr(TMA)‐primed population inhibited the TMA DTH reaction in the A/J (H‐2a, Igh‐1e) but not in the idiotype‐positive A.SW (H‐2s, Igh‐1e), allotype‐congenic strain C57.Ige nor in the idiotype‐negative C57BL/6J partner. The role of the tyr(TMA)‐primed, idiotype‐specific Ts population in regulating TMA‐related responses via the idiotypic network is discussed.
The nylon wool adherence marker of the B cell lineage appears at the resting pre‐B cell stage
Authors: Deslauriers‐Boisvert Noélla , Mercier Ginette , Lafleur Louis
Published: February 2007

The proliferative state of functionally defined populations of size‐separated pre‐B cells was investigated. The results presented here support the hypothesis that pre‐B cells are in the G2 phase when stable membrane IgM is first expressed. Small resting precursor cells significantly adhere to nylon wool columns, unlike larger cycling cells which can be enriched in the nonadherent fraction. These results suggest that the nylon wool “receptor” is a useful early B cell marker.

Since the in vitro recruitment of both cycling and resting precursors was shown to be essentially dependent on agar mitogen(s), cumulative data suggest that the receptors for agar mitogen(s) appear shortly before surface IgM on proliferating pre‐B cells. Nylon wool adherence potential develops next on their resting progeny, followed by full lipopolysaccharide reactivity as cells further mature.
Behavior of soluble human 125I‐labeled C3b, the third component of complement, after binding to human cells
Authors: Charriaut Christiane , Barel Monique , Frade Raymond
Published: February 2007

The behavior of 125I‐labeled C3b incubated with two C3b receptor‐positive cells (human erythrocytes and the B lymphoblastoid Raji line), one C3b receptor‐negative cell (T lymphoblastoid CEM line) and solubilized membranes from each cell was analyzed by sucrose density gradient (SDG) and sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Whichever whole cell was tested, the unbound 125I‐labeled C3b recovered in the cell supernatant was not cleaved. When 125I‐labeled C3b was bound to whole cells or incubated with solubilized membranes, three different activities were detected: (a) nonspecific C3b polymerization, induced on the membrane of C3b receptor‐positive or C3b receptor‐negative cells; (b) specific C3b receptor activity solubilized only from the membrane of the two C3b receptor‐positive cells and (c) C3b hydrolytic activity, inhibited by 5 x 10−4 M phenyl methyl sulfonyl fluoride, only extracted from human erythrocyte membranes and carried by a molecule different from that of C3b receptor.

C3b receptor activity solubilized from Raji and human erythrocyte membranes was detected by a 12 S peak complex formation on a 10‐30 % SDG and characterized by an affinity constant of 2 x 107 to 4 x 107 mol−1.

Hydrolysis of labeled C3b (Mr = 175 000) by solubilized human erythrocyte membranes led to the formation of a split product of Mr = 35 000 consisting of two disulfide‐linked polypeptide chains of Mr = 17 000. This is the first report of a breakdown of C3b on cell membranes different from the physiological breakdown described in the fluid phase.
Different expression of Lyt differentiation antigens and cell surface glycoproteins by a murine T lymphoma line and its highly metastatic variant
Authors: Altevogt Peter , Kurnick James T. , Kimura Arthur K. , Bosslet Klaus , Schirrmacher Volker
Published: February 2007

Cloned lines of the methylcholanthrene‐induced DBA/2 T lymphoma Eb and its highly metastatic variant line ESb were analyzed for differences in the expression of serologically detectable cell surface differentiation markers. Flow cytofluorographic analysis of cells stained with fluorescein isothiocyanate‐conjugated monoclonal rat anti‐mouse Thy‐1, Lyt‐1, Lyt‐2 and compelement‐dependent cytotoxicity with mouse alloantisera against Lyt‐3.2 and Ly‐6.2 revealed, for the parental low metastasizing line, Eb, a phenotype of Thy‐l+, Lyt‐1−, Lyt‐2+, Lyt‐3+, Ly‐6+, whereas the highly metastasizing variant line typed as Thy‐1−, Lyt‐1+, Lyt‐2−, Lyt‐3−, Ly‐6−. Analysis of galactose oxidase/NaB3H4‐labeled glycoproteins from Eb and ESb clones by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate showed further phenotypic differences. Selective binding of radiolabeled glycoproteins to Helix pomatia or Vicia villosa‐Sepharose, respectively, allowed the identification of T130 to be expressed on Hb cells and T145 to be expressed on some ESb clones. The latter antigen is expressed on murine cytotoxic T lymphocytes. Immune precipitation analysis revealed that Eb and ESb bear different molecular forms of the T200 antigen. Comparisons of iodinated surface proteins derived from tumor cells either treated or untreated with tunicamycin indicated that many of the differences in membrane proteins between Eb and ESb cells could be attributed to differences in glycosylation. Our results, derived from a defined tumor system of lymphoid origin, show that the progression from a low to a high malignant tumor line can be associated with changes in the expression of various defined cell surface differentiation antigens. The question of a possible relationship between tumor progression and cell differentiation or dedifferentiation is discussed.
Macrophage activation by interferon: dissociation between tumoricidal capacity and suppressive activity
Authors: Boraschi Diana , Soldateschi Dario , Tagliabue Aldo
Published: February 2007

Resident peritoneal macrophages (Mϕ) from untreated mice and inflammatory Mϕ induced by a sterile irritant were able to exert significant suppressive activity on lymphocyte functions. Mϕ‐mediated suppression was evident in lymphocyte proliferation and in a proliferation‐independent lymphocyte response (i.e. lymphokine production). The lymphokine macrophage‐activating factor (MAF), which enhances tumoricidal capacity of inflammatory but not of resident Mϕ in vitro, was ineffective in modulating suppressive activity of both resident and inflammatory Mϕ. In contrast, a significant effect on Mϕ‐mediated suppression was observed upon treatment with IFN‐β. In fact, suppression of lymphoproliferation and of lymphokine production by either resident or inflammatory Mϕ was significantly decreased or abolished by IFN‐β. Like MAF, IFN‐β was able to increase Mϕ cytotoxicity against tumor cells. Such an effect, however, was evident in both resident and inflammatory Mϕ, thus confirming different Mϕ activation mechanisms for MAF and IFN‐β.

These data indicate that IFN‐β acts mainly on mature Mϕ, which thus appear as the major Mϕ type involved in suppression. The contrasting effects of IFN‐β on Mϕ suppression and on Mϕ‐mediated cytotoxicity strongly suggest a dissociation between the 2 induction mechanisms of suppression and cytotoxicity.

The in vivo relevance of these two IFN activities was demonstrated by treating mice with the potent IFN inducer polyinosinic polycytidylic acid (poly(I) poly(C)). Mϕ from poly(I) poly(C)‐primed mice simultaneously showed enhanced tumoricidal activity and complete abolishment of suppressive capacity.
Independent segregation of NZB immune abnormalities in NZB X C58 recombinant inbred mice
Authors: Bocchieri Maureen H. , Cooke Anne , Smith J. Bruce , Weigert Martin , Riblet Roy J.
Published: February 2007

The study of NZB X C58 recombinant inbred mouse strains has revealed independent segregation of naturally occurring thymocytotoxic antibody and Coombs' anti‐erythrocyte autoantibody. The lack of concordance of either of these autoantibodies with known heavy and light chain markers suggests that the autoantibodies are produced as a result of regulatory gene defects rather than alterations of antibody structural genes. Further, lack of concordance of the various autoimmune traits with eachother or with H‐2 or virus expression suggests that the autoimmune phenotype is not the result of a single “autoimmunity” gene but rather the outcome of faulty regulation of a number of independently segregating genes.
Thy‐1 determinants are present on many murine hematopoietic Cells other than T Cells
Authors: Basch Ross S. , Berman Joan W.
Published: February 2007

The development of a highly amplified immunofluorescence assay and the availability of monoclonal anti‐Thy‐1 antibodies have provided the methodology to reexamine the presence of Thy‐1 antigen on murine lymphohematopoietic cells. The representation of this antigen is not, as previously believed, restricted to the T cell compartment of these cells. It is present on a significant number of mouse bone marrow cells (25–30%), including, as in the rat, multipotential stem cells, prothymocytes and some B cell precursors. Eosinophils and some immature myeloid cells are also antigen‐positive.
Description of a Qa‐2 like alloantigen (Qa‐m2)
Authors: Hogarth P. Mark , Crewther Pauline E. , McKenzie Ian F. C.
Published: February 2007

Several new aspects of the chemistry, genetics and cellular distribution of the murine Qa‐2 alloantigen were apparent in an analysis of this antigen using monoclonal antibodies recognizing a Qa‐2‐like antigen called Qa‐m2. Immunoprecipitation and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis identified the Qa‐m2 alloantigen as a two‐chain structure composed of a 39 000 dalton heavy chain and a 12000 light chain which is probably β2‐microglobulin; the heavy chain was readily distinguished from that of H‐2. In addition, the expression of Qa‐m2 alloantigens on the cell surface was found to be controlled by the H‐2D gene with H‐2Db strains carrying approximately 8‐10 times greater amounts of Qa‐m2 than strains carrying the H‐2Dd or H‐2Dq alleles. Finally, the Qa‐m2 antigen, found predominantly on peripheral T cells, was present on only 10% of thymus cells. However, subpopulations of B cells (approximately 25% of all B cells) and bone marrow cells (15‐20%) were also reactive. The monoclonal anti‐Qa‐m2 antibodies differed in their reactions from that reported for the conventional anti‐Qa‐2 sera, which must, therefore, be complex. The monoclonal antibodies may be useful reagents for functional analysis of T and B cell subpopulations.
Immunogenic variants obtained by mutagenesis of mouse mastocytoma P815. III. Clonal analysis of the syngeneic cytolytic T lymphocyte response
Authors: Maryanski Janet L. , Van Snick Jacques , Cerottini Jean‐Charles , Boon Thierry
Published: February 2007

The cytolytic T lymphocyte (CTL) response of syngeneic mice to antigenic variants obtained by mutagenesis of mastocytoma P815 was analyzed at the clonal level. Estimates of the frequency of CTL precursor cells in spleens from mice immunized with P 815 variants ranged from lo4 to 2 X 10−3. This frequency could be increased approximately 100 times by stimulating immune spleen cells in mass culture for 6‐8 days with the immunizing variant. Specificity analysis of a large number of individual CTL clones demonstrated the existence of two distinct populations of CTL. Some CTL clones lysed exclusively the immunizing variant, while others lysed equally well all P815 targets, but not syngeneic tumor L1210. These results provide direct evidence for the existence of new, individual specificities on P815 variants in addition to a common antigen already present on the original P815 cells. This confirms that a variety of new antigens can be induced by mutagenesis on the same background cell. Stable, highly active CTL clones specific for either individual variant antigens or common P815 antigens could be maintained in long‐term culture.
Limiting dilution analysis of human peripheral blood mononuclear leukocytes that react to human amnion cells and protect these against viral challenge
Authors: Rönnblom Lars , Alm Gunnar V.
Published: February 2007

Human peripheral blood mononuclear leukocytes (PBL) cocultured with WISH human amnion cells rapidly produced α‐type interferon (IFN‐α) and in an IFN‐dependent manner protected the WISH cells against the cytopathic effects caused by vesicular stomatitis virus. When the number of PBL per WISH cell monolayer culture was diluted out using multiple WISH microtiter plate cultures for each PBL dilution, the protection of the WISH cultures appeared as an all‐or‐none phenomenon. Thus, at one small mean number of PBL per culture, some cultures were protected against the virus, while others were not. Limiting dilution analysis, with plot of the logarithm of the fraction of nonprotected WISH cell cultures at each PBL dilution against the mean number of PBL per culture, yielded straight lines with an intercept on the ordinate close to 1. This indicated a single‐hit event due to the function of a single type of limiting “protecting unit”. The frequency of this limiting unit in the PBL population could reproducibly be determined for an individual blood donor. For a limited number of different blood donors it ranged from 1/400 to 1/3000. These minimal frequency estimates were considerably increased (40‐300%) after 3 h preincubation of PBL with IFN‐α.

Two major alternatives were considered with regard to the nature of the limiting protecting units. They were either IFN‐producing cells operating alone, or they were inducer‐type cells that possibly used IFN as a mediator to activate protecting cells present in excess in the coculture system. The second possibility was favored, and the relation of the protecting cell type to the natural killer cell system is discussed herein.
Analysis of DR‐like molecules on a marmoset Epstein‐Barr virus‐induced cell line using a monomorphic anti‐human HLA‐DR monoclonal antibody
Authors: Teillaud Jean‐Luc , Charron Dominique , Goujet‐Zalc Cécile , Mahouy Guy
Published: February 2007

Mouse anti‐HLA D region‐related (DR) monoclonal antibodies have been found to cross‐react with peripheral blood leukocytes from one primate species, the common marmoset (Callithrix jacchus). Immunoprecipitates of radioactively labeled cells extracted from a marmoset Epstein‐Barr virus‐induced cell line were analyzed by one‐and two‐dimensional gel electrophoresis and compared with the DR antigens of a human lymphoblastoid B cell line. Two chains of estimated molecular weights of 34000 (α) and 28000 (β), similar to the human α and β chains, have been observed in marmoset immunoprecipitates. Additionally, a set of spots located in the same area as the set of invariant spots found in human HLA‐DR antigens is shown by two‐dimensional gel electrophoresis. Thus, cross‐reacting anti‐human HLA‐DR monoclonal antibodies could be used to analyze the expression and the structure of marmoset DR‐like antigens.