bluuebunny/crossref_metadata_2025 huggingface dataset:
The private specificity H‐2.4 and the public specificity H‐2.28 of the D region are expressed on two independent polypeptide chains
Authors: Neauport‐Sautes Catherine , Morello Dominique , Freed J.H. , Nathenson S.G. , Démant P.
Published: February 2007

The antigenic specificities H‐2.4 (private) and H‐2.28 (public) in the H‐2a haplotype are controlled by the D region of H‐2 as defined by the available recombinants. In previous studies we have demonstrated by the antibody‐induced redistribution method that the antisera against these specificities contain antibodies against at least two different polypeptide chains. We here report the results of the indirect immunoprecipitation of radiolabeled antigens after solubilization with Nonidet‐P40. The antisera against the two specificities precipitated from such extracts two different and independent polypeptide chains, indicating that the products of the D region, as presently defined, comprise at least two different molecules. The molecular weight of both chains is approximately 45 000, which is similar to other molecules bearing private H‐2 antigenic specificities. Consequently, the chromosomal segment presently defined by recombination studies as the D region, must contain another locus, controlling the second polypeptide chain which is detectable by anti‐H‐2.28 antisera, besides the H‐2D locus which controls the polypeptide chain bearing the private specificity H‐2.4 as well as most of the public specificities.
The role of the Fc receptor (FcR) of thymus‐derived lymphocytes I. Presence of FcR on cytotoxic lymphocytes and absence of direct role in cytotoxicity
Authors: Leclerc J.C. , Plater Christine , Fridman W.H.
Published: February 2007

Cytotoxic T lymphocytes (CTL) were prepared by injecting C3H/He (H‐2k) thymocytes into host‐irradiated BALB/b (H‐2b) mice. Specific cytolysis was measured on MBL2 lymphoma cells from C57BL/6 (H‐2b) mice. Alloantigen‐activated T cells (ATC) were taken from the spleens of the recipients at day 5 and separated according to size and/or to the presence of membrane Fc receptors (FcR) by the use of velocity sedimentation techniques. The data showed that CTL were found in populations of lymphocytes heterogeneous in cell size and were always present in the FcR‐positive population. Depletion of FcR‐positive ATC, after rosetting with IgG‐sensitized sheep erythrocytes led to an abolishment of cytolytic activity while enrichment in FcR‐positive ATC led to a parallel increase of cytolytic activity. Taking advantage of the rapid release of FcR at 37°C by ATC, we investigated the direct involvement of the FcR molecule in cytolysis. We found that ATC which had released their FcR after pre‐in‐cubation for 2 h at 37°C exerted the same level of cytotoxicity as control ATC incubated at 4 °C. The data lead us, therefore, to conclude that FcR may be a marker of differentiation of cytotoxic T cells found in the spleen, but does not itself play a role in the cytolytic reaction.
Isolated hapten‐binding receptors of sensitized lymphocytes I. Receptors from nylon wool‐enriched mouse T lymphocyte lack serological markers of immunoglobulin constant domain but express heavy chain variable portions
Authors: Krawinkel U. , Cramer M. , Imanishi‐Kari Thereza , Jack R.S. , Rajewsky K. , Makelä O.
Published: February 2007

Hapten‐binding receptor material was isolated from hapten‐sensitized mouse lymphocytes, as described previously (Eur. J. Immunol 1976.6: 529; Cold Spring Harbor Symp. Quant. Biol. 1977. 41: 285). The material was separated into a fraction expressing immunoglobulin determinants (anti‐Ig+ fraction) and a fraction lacking determinants of the known Ig constant domains (anti‐Ig−fraction). We present further evidence in support of the notion that the anti‐Ig+ fraction is B cell‐derived, whereas the anti‐Ig− fraction originates from T lymphocytes. Receptors derived from C57BL/6 mice of the anti‐Ig_ phenotype with specificity for the hapten (4‐hydroxy‐3‐nitrophenyl)acetyl (NP) are found to express markers which are characteristic for the variable portion of primary anti‐NP antibodies. One of these markers relates to the fine specificity of hapten binding [6, 24], the other is defined by anti‐idiotypic antibodies. Genetic studies show that the expression of these markers both in antibodies and the anti‐Ig− receptor fraction is controlled by genes in the heavy chain linkage group.

The results demonstrate that in this system, humoral antibodies and receptor molecules of both the anti‐Ig+ and anti‐Ig− phenotype bind the hapten with strikingly similar affinity and fine specificity. More specifically, they suggest that the molecules in the anti‐Ig− receptor fraction carry the variable region (and in fact the en tire variable region) of the Ig heavy chain.
An IgM‐producing tumor with biochemical characteristics of a small B lymphocyte
Authors: Bergman Y. , Haimovich J. , Melchers F.
Published: February 2007

A lymphocytic tumor, 38C‐13, induced by the chemical carcinogen 7, 12‐di‐methylbenz(a)anthracene in C3H/eB mice and adapted to tissue culture, produces 7–8 S IgM with “core” carbohydrates (N‐acetylglucosamines, mannoses), but not “branch” carbohydrates (neuraminic acids, fucoses, galactoses) attached to the μ heavy, but not to the light chains. Turnover of the 7–8 S 38C‐13 IgM is slow (half disappearance time = 10–15 h). The IgM is released from the cells as 7–8 S IgM. The ratio of IgM synthesis to the synthesis of all cellular glycoproteins is 0.005–0.01. After comparison of these data with data obtained with normal B lymphocytes before and after mitogenic stimulation, we conclude that 38C‐13 tumor cells are transformed counterparts very near or within the population of small, mitogen‐sensitive, resting B lymphocytes.
Rat bile as a convenient source of secretory IgA and free secretory component
Authors: Lemaître‐Coelho Isabel , Jackson G. D. F. , Vaerman J. ‐P.
Published: February 2007

Rat hepatic bile contains three proteins as major constituents: secretory IgA (SIgA), free secretory component (FSC) and albumin. Traces of α‐macroglo‐bulin, transferrin, IgG and IgM are also detectable. The bile duct daily pours between 5–12 mg each of SIgA and FSC into the rat duodenum. The origin and function of these proteins in bile may represent important clues in the understanding. of the SIgA system.
Colony growth of human T lymphocytes in agar: effect of a soluble factor from adherent cells
Authors: Claësson M.H. , Whittingham S. , Rodger M.B. , Burgess A.W.
Published: February 2007

When mononuclear cells from peripheral human blood were plated directly in agar medium containing phytohemagglutinin (PHA) and sheep red blood cells and cultured for 6–7 days, discrete colonies of 4–50 lymphocytes were formed. The plating efficiency was one colony per 50–100 cells plated, but this was reduced by approximately 85 % when adherent cells were removed from the mononuclear cell suspension prior to culture. PHA‐induced colony formation by autologous or homologous nonadherent cells could be completely restored by culturing nonadherent cells over a feeder layer of adherent cells or addition of the medium in which adherent cells had been cultured. Thus, adherent cells were presumed to secrete a stable soluble factor which supported PHA‐induced colony formation.

This active factor in conditioned medium from adherent cells could be stored for several months at –10°C, and was relatively stable when heated to 56°C for 30 min. It did not bind to concanavalin A‐Sepharose, had a molecular weight greater than 10 000 daltons, was inactivated by treatment with pronase but not by DNAse, RNAse or lipase, and was active at a concentration of 1 %. Adherent cells and culture media from human peritoneal macrophages and fibroblasts did not stimulate colony formation in nonadherent cells, and likewise culture medium from nonadherent cells or purified T lymphocytes was inactive. When concentrates of conditioned medium from cultures of adherent cells were fractionated on a Sephadex G‐100 column two peaks of activity were obtained: a sharp peak with a molecular weight of approximately 100 000 daltons and a smaller peak with a molecular weight between 12 000 and 15 000 daltons.

Our data indicate that a factor or factors of high molecular weight are produced by cultures of adherent mononuclear cells; these factors support the formation of PHA‐induced colonies by human T lymphocytes.
Cytotoxic T cells to type A influenza virus; viral hemagglutinin induces A‐strain specificity while infected cells confer cross‐reactive cytotoxicity
Authors: Zweerink H.J. , Askonas Brigitte A. , Millican Dianne , Courtneidge Sara A. , Skehel J.J.
Published: February 2007

This paper deals with the generation and specificity of cytotoxic T cells directed to cells infected with type A influenza viruses. Mice were primed in vivo and their spleen cells restimulated in vitro. Four type A viruses with serologically distinct surface proteins are equally effective in secondary stimulation of cytotoxicity regardless of the viral strain used for priming. The resulting cytotoxic cells will lyse cells infected with any of the 4 type A viruses. Cross‐reactivity between type A and B influenza viruses does not occur.

Competition experiments show that the cross‐reactive cytotoxic T cells contain a minor population of cells with increased affinity for the type A virus strain used for priming, but the majority of the cells do not distinguish between the type A virus strains.

Virus replication is not required for the secondary generation of cytotoxic T cells; inactivated virus and viral hemagglutinin can serve as stimulators. Hemagglutinin derived from type A/Jap/Bel selects cytotoxic cells with specificity restricted to A/Jap/Bel originally used for priming and A/Jap which shares the hemagglutinin. This secondary stimulation can be achieved only when either of those two type A viruses are used for priming.

The results indicate that hemagglutinin is one of the viral proteins recognized by cytotoxic T cells; however, it is not clear which viral protein(s) are responsible for cross‐reactivity.
Human B cell alloantigens: separation from other membrane molecules by affinity chromatography
Authors: Cresswell P.
Published: February 2007

Human Ia‐like alloantigens have been solubilized from membranes of B lymphoblastoid cell lines using sodium deoxycholate (DOC). They have been purified by affinity chromatography using specific rabbit antibodies bound t o an agarose column, eluting the antigen at pH 1 1 .O in the presence of 0.5 % DOC. The isolated, purified, material contained two proteins of molecular weights 35 000 and 27 000 by sodium dodecyl sulfate gel electrophoresis, apparently noncovalently associated with each other. The molecules were completely separated from the soluble products of the HLA‐A, B and C loci and retained serological activity as measured by their capacity t o inhibit the lysis of B lymphoblastoid cell lines by B cell‐specific alloantisera.
Inhibition of antibody production in plasmacytoma cells by antigen
Authors: Abbas A.K. , Klaus G.G.B.
Published: February 2007

Tissue culture‐adapted MOPC 315 mouse plasmacytoma cells which secrete monoclonal anti‐DNP IgA antibody, were cultured with a variety of DNP‐carrier conjugates and the production of IgA measured by pulse labeling with [3H]leucine and by plaque‐forming cell assays. DNP‐coupled bovine, human and rabbit 7‐globulins (containing 9 to 12 DNP groups per 50 000 mol.wt. of carrier) inhibited the synthesis and secretion of IgA by 40 to 80 %. This inhibition was specific, since unconjugated globulins were ineffective, non‐IgA proteins and DNA synthesis remained unaffected, and DNP‐globulins had no effect on X5563 cells which do not bind DNP. The degree of suppression of antibody production depended on the concentration and epitope density of the antigen and on the duration of exposure of cells to it, and was not attributable to absorption of secreted antibody by cell‐bound antigen. Comparably substituted DNP conjugates of F(ab')2 and intact globulins were equally inhibitory. The inhibition of antibody synthesis by DNP‐BGG was reversible following removal of the antigen. This phenomenon is similar in many respects to the antigen‐induced blockade of normal antibody‐secreting cells, and provides a valuable model system for analyzing the mechanisms of antigen‐mediated cellular inactivation.
Increased growth of Rous sarcomas in chickens pretreated with formalinized syngeneic tumor cells
Authors: Schierman L.W. , Watanabe D.H. , Mcbride R.A.
Published: February 2007

The effect of inoculating formalinized syngeneic or allogeneic Rous sarcoma cells on the growth of Rous sarcoma virus (RSV)‐induced tumors in two related inbred strains of chickens was studied. Chickens from both strains that received three weekly inoculations of syngeneic tumor cells had a significant increase in tumor growth and mortality after subsequent challenge with RSV. Development of RSV‐induced tumors in chickens pretreated with formalinized allogeneic tumor cells (i.e. incompatible for major histocompatibility complex (MHC) antigens) was similar to what we observed in nonpretreated control chickens.

The finding that the tumor‐host relationship is altered only in chickens pretreated with formalinized syngeneic RSV‐transformed cells, suggests that tumor‐associated antigens of Rous sarcomas are modified MHC antigens analogous to “altered self” antigens thought to be present on certain virus‐infected cells. If this hypothesis is correct, the results we obtained with formalin‐killed syngeneic tumor cells can be explained on the basis of three possible mechanisms: immunological enhancement, immune tolerance or induction of antibody to anti‐tumor idiotype. The merits of each mechanism in accounting for the results are discussed.
Immune interferon I. Production by lymphokine‐activated murine macrophages
Authors: Neumann Christine , Sorg C.
Published: February 2007

Unfractionated murine spleen cells produce immune interferon (type II) upon stimulation with antigen or mitogen. When spleen cells were passed over glass bead columns, interferon production decreased whereas the mitotic response to the stimulants drastically increased. When these cells were further purified over nylon wool columns, interferon production was totally abolished whereas thymidine incorporation in stimulated cultures was invariably high. Interferon production by nylon wool column‐purified lymphocytes could be restored with macrophages grown from bone marrow cultures or spleen cells but not with macrophages from proteose peptone‐induced peritoneal exudate cells. It was also found that pure macrophage cultures from spleens of BCG‐immunized mice consistently produced interferon activity without any further stimulation. When culture supernatants of activated T lymphocytes, which did not contain any interferon activity, were transferred to macrophage cultures from different sources and incubated for 45 h, interferon activity could be detected in supernatants of macrophage cultures from bone marrow and spleen but not in those from proteose‐induced peritoneal exudate cells. It is concluded that certain macrophage populations can be induced to produce interferon activity whereas others are refractory to this induction which appears to be linked to their differentiation state.
Autoagglutinin produced by organ fragment cultures of mouse spleen
Authors: Jablonska Krystyna F.
Published: February 2007

Mouse spleen fragment microcultures produce a heat‐labile substance which agglutinated syngeneic erythrocytes. The substance reacted with an antigen present on some strains of mouse erythrocytes and on rat erythrocytes, but absent from other strains of mouse erythrocytes and from guinea pig, rabbit or sheep erythrocytes. Agglutination was inhibited by antisera to mouse immunoglobulins except for antisera specific to mouse IgM which enhanced agglutination. The agglutinin sedimented with 19 S Ig on ultracentrifugation and was destroyed by pretreatment with mercaptoethanol. Using a rosette assay increased numbers of cells, specifically binding syngeneic erythrocytes by means of a surface Ig receptor were demonstrated in spleen fragment micro‐cultures. It is considered that the agglutinin is a noncomplement‐activating IgM autoantibody and that the precursors of the cells producing the autoantibody are detected by the rosette assay.
Immunofluorescent studies of the development of pre‐B cells, B lymphocytes and immunoglobulin isotype diversity in humans
Authors: Gathings W.E. , Lawton A.R. , Cooper M.D.
Published: February 2007

Immunofluorescent techniques were used to examine several aspects of B cell ontogeny in humans. Large lymphoid cells containing intracytoplasmic IgM (pre‐B cells) were present in fetal liver as early as 7 weeks of gestation, approximately 2 weeks prior to the appearance of surface IgM positive (sIgM+) B lymphocytes. Pre‐B cells outnumbered sIgM+ B lymphocytes in fetal liver up until the 13th week of gestation. In fetuses older than 13 weeks, pre‐B cells and sIgM+ B lymphocytes were present in approximately equal proportions in liver and bone marrow. Pre‐B cells in fetal liver, and fetal and adult marrow, were large and small (indicating a heterogeneous population of cytoplasmic IgM+. SIg‐ cells in these sites), while only the small pre‐B cells were present in fetal spleen, blood and lymph node. Lymphocytes bearing sIgG were detected earlier than those bearing sIgD or sIgA, which were present by the 12th gestational week. Using double‐staining techniques, we determined that during fetal life, (a) the proportion of B lymphocytes bearing only sIgM, as opposed to those bearing both sIgM and sIgD, was much higher in liver and bone marrow than in spleen, blood and lymph node, and (b) sIgG, sIgA and sIgD appear independently on lymphocytes bearing sIgM. Studies of the frequency of double‐stained cells for each combination of the four sIg isotypes indicated that B lymphocytes from neonatal humans may simultaneously bear three or more sIg isotypes, whereas sIgG+ and sIgA+ B lymphocytes in adult blood usually express only the single isotype. Lower concentrations of anti‐y antibodies were required for modulation of sIgM from B lymphocytes of fetal liver and adult bone marrow than for equivalent removal of sIgM from circulating B cells of mature individuals.

In conjunction with data obtained in mice, our observations indicate that (a) the presence of large and small pre‐B cells, (b) a high ratio of sIgM single to sIgM.sIgD double B lymphocytes, and (c) increased sensitivity to modulation of B cell sIgM by divalent anti‐μ antibodies define the fetal liver and adult bone marrow as bursa‐equivalent sites in humans. Our results are consistent with a model of isotype diversification in which immature sIgM+ cells give rise to B cell sublines devoted to synthesis of each of the Ig classes, and sIgD is secondarily expressed on unstimulated B cells of all of these sublines.
Ir gene control of carrier recognition III.cooperative recognition of two or more carrier determinants on insulins of different lspecies
Authors: Keck K.
Published: February 2007

When crosses between different nonresponder strains to pig and bovine insulin were tested, some cases of complementation could only be achieved if one of the strains had C3H bavkgrounmd,e.g.(C3H.SW × C3H/He)F1 and (C57BL/6 × C3H/He)F1 show complementation, whereas (C57BL/10 × B10.BR)F1 do not.

It is suggested that three genes are necessary for the complementation, two genes in the H‐2 region and an additional gene in the C3H bacjground. It was therefore supposed that this type of complementation might be due to a cooperative recognition byone of the parental strains. This possibitility was tested by coimmunization experiments performed with the parental strains C3H/He and C57BL/6.

Insulin to which these strains respond (sheep or bovine insulin, respectively) was injected together with an excess of an insulin nonimmunogenic in the parental strins but immunogenic to the hybrids (pig insulin).It proved that under these conditions the response of C3H/He mice to sheep insulin was reduced by more than 90%, whereas C57BL/6 mice gave a normal response to bovine insulin. However, both strains were now able to respond to the pig insulin as shown bythe antibody production to fluoresceinthiocarbamyl groups coupled to pig insulin. This shows that the missing carrier determinant can be provided by a different molecule.

The results are discussed in terms of a multideterminant recognition of the antigen at the carrier level. The recognition of each carrier determinant can be provided by a different molecule.
Two structurally similar haptens each induce a different inherited idiotype
Authors: Mäkelä O. , Ju Shyr‐Te , Nisonoff A.
Published: February 2007

When mice of the A/J strain were immunized with azobenzenearsonate (ABA) directly coupled to a protein, they produced antibodies that share an inherited cross‐reactive idiotype (CRI). In the antigenic determinant that induces CRI, ABA is very probably coupled to tyrosine, and the structure that protrudes from the polypeptide backbone has two benzene rings and a molecular weight of 419. When this same structure is separated from the polypeptide backbone by a spacer of 99 daltons, it induces a different inherited idiotype (ABA‐HOP‐e) in the same strain of mice. Our data suggest that antibodies with the idiotype CRI recognize the terminal benzene ring and the azo group, but do not fit closely around the second ring structure. Antibodies with the idiotype ABA‐HOP‐e have fine specificity for both benzene rings. Both idiotypes are inherited and both are linked to genes controlling constant regions of the heavy chains.
Surface immunoglobulin on rabbit lymphoid cells VI. Failure to detect d and e group immunoglobulin allotypes on lymphocytes by immunoelectron microscopic labeling.
Authors: Linthicum D.S. , Sell S. , Mandy W.J.
Published: February 2007

Surface immunoglobulin allotypes on rabbit perpheral bloodlymphocytes (PBL)and spleen lymphocytes are detected by an immunoferritin labeling technique for electron microscopy. Human red blood cells, chemically coated with purified rabbit lgG of specific allotypes, served as test cells to assess the labeling speecificity and efficiency. Immunoelectron microscopic labeling reveals that groups a,b,d and e allotypic specificities are readily detectable on passively coated test cells. However, only a and b group markers are detectable on lymphocytes. On rabbit PBL both a (VHof Fd reguib) abd b (kappa chain constant region);group alloytpes are detectable (73‐78% and 68‐77%, respectively); on spleen cells, 46% and 52‐55%are positive for a and b locus allotypes, respectively.The d and e allotypes (i.e.γ chain‐specific) are undetectable on PBL or on spleen lllllymphocytes using this method. We conclude that the d and e group allotypes are either not present on the lymphocyte surface or are buried in the surface memberane and unaccessible to the antisera used in this immunoferritin labeling technique.
Graft rejection in earthworms: an electron microscopic study
Authors: Linthicum D. S. , Marks D. H. , Stein Elizabeth A. , Cooper E. L.
Published: February 2007

Graft rejection in the earthworm, Lumbricus terrestris, is mediated by granulocytic coelomocytes (neutrophils, by light microscopy). Within 1–3 days post‐transplantation of body‐wall xenografts, granulocytic coelomocytes migrate to the transplant site, penetrate the graft matrix, and actively phagocytize viable muscle fibers. Destruction of muscle tissues may be augmented by lymphocytic coelomocytes (basophils, by light microscopy), but these cells participate in a minor way and do so very late in the rejection process (days 11‐13). Xenografts, autografts and sham‐operated controls display generalized inflammatory reactions, including coelomocyte infiltration into the grafted tissue. In autografts, however, granulocytes only penetrate the inner longitudinal muscle layers and extensive infiltration, persistence and complete destruction never occur. Lymphocytic coelomocytes are not observed in autografts or sham‐operated controls. Graft rejection by leukocytes in an advanced invertebrate confirms that aspects of cell‐mediated immunity evolved early in phylogenetic history.
A serum‐free medium for the Mishell‐Dutton system
Authors: Burger M.
Published: February 2007

A serum‐free medium which provides high recoveries of plaque‐forming cells in the primary immune response to sheep erythrocytes is described. In this medium the serum was replaced by heated fetuin and by excess of nonessential amino acids. Glycopeptides, obtained by excessive pronase treatment of fetuin were partially capable of replacing the nonhydrolyzed fetuin.
Suppression of an in vitro humoral immune response by cultured fetal thymus cells
Authors: Luckenbach G. A. , Kennedy Marilyn M. , Kelly Anita , Mandel T. E.
Published: February 2007

We studied the function of fetal thymocytes, derived from thymus progenitor cells of 14‐day‐old fetuses in an organ culture system, in an in vitro humoral immune response. The unprimed cultured fetal thymocytes suppressed the T‐dependent primary immune response of adult syngeneic spleen cells against sheep red blood cells, but failed to suppress the response against the T‐inde‐pendent antigen NIP‐POL [4(hydroxy‐3‐iodo‐5‐nitrophenyl)acetyl‐coupled polymerized flagellin]. The suppression was abolished by anti‐Thy‐l serum and complement treatment. Using a differential killing procedure, the suppressor cells were characterized as “low” Thy‐1 cells. In addition, they were resistant to hydrocortisone. Suppression could only be achieved when the cultured fetal thymocytes were added during the first 48 h of culture, suggesting that their action occurred during the induction phase of the response. The implications of the high frequency of suppressor cells during fetal life are discussed.
Immune responses to weakly immunogenic virally induced tumors I. Overcoming low responsiveness by priming mice with a syngeneic in vitro tumor line or allogeneic cross‐reactive tumor
Authors: Galili Naomi , Devens B. , Naor D. , Becker Susanne , Klein Eva
Published: February 2007

This report describes model systems which show low primary in vitro syngeneic cytotoxic responses to a Moloney‐induced YAC tumor (syngeneic in A mice) and a Rauscher‐induced RBL5 tumor (syngeneic in C57BL/6 mice) and examines different approaches to overcome these defects.

Two major findings were obtained: (a) spleen cells from A mice, injected with tumor cells from an in vitro tumor line YAC‐1, derived from YACL, could generate a significant syngeneic cytotoxic response. In contrast, spleen cells from A mice injected with tumor cells from the in vivo tumor line failed to generate a syngeneic cytotoxic response. Thus, tumor cells from the in vitro line were more immunogeneic that those from the in vivo line. (b) Spleen cells from A mice which were injected with the crossreactive allogeneic tumor RBL5, could generate significant cytotoxic responses to the syngeneic tumors YAC and YAC‐1. Similarly, spleen cells from C57BL/6 mice injected with the cross‐reactive allogeneic tumor YAC‐1, could generate a significant cytotoxic response to the syngeneic tumor RBL5. Thus, cross‐reactive allogeneic tumors could stimulate syngeneic cytotoxicity. The theoretical and the practical implications of these studies are discussed.
Behavior of Biozzi high and low responder mice upon infection with Schistosoma mansoni
Authors: Blum Konstanze , Cioli D.
Published: February 2007

Mice genetically selected for high (Ab/H) or low (Ab/L) humoral antibody responses were infected with Schistosoma mansoni in order to assess the role of antibodies in innate and acquired immunity to this parasite. Ab/H mice produced higher levels of humoral antibodies to schistosome antigens, but were more susceptible to infection than Ab/L mice. This was shown by the higher number of parasites recovered from Ab/H mice, by the larger size of the parasites themselves, by the number of schistosome eggs and their rate of deposition in the host liver. In addition, Ab/L mice could develop an acquired resistance to schistosome re‐infection which was as good as, or possibly even better than the resistance developed by Ab/H mice. These findings suggest that humoral antibodies per se may not play a critical role in schistosome immunity, and at the same time call attention to the possible importance of macrophages in determining the results observed.
Localization of antigenic activity and immunogenic capacity in different conformational domains of procollagen peptide
Authors: Rohde H. , Nowack H. , Timpl R.
Published: February 2007

The antibody response to the amino‐terminal CNBr peptide of sheep procollagen which consists of a globular and a collagenous segment, was studied in inbred strains of mice. The determinants reacting with antibody could be localized in the globular domain and were lost by reduction of disulfide bridges. The ability to induce an antibody response required the collagen‐like sequences and was independent of the triple‐helical conformation of this segment. The data were interpreted as indicating a different conformation dependence of hapten and carrier determinants.
Role of B cells in the expression of genetic resistance to growth of Rous sarcoma in the chicken
Authors: McBride R. A. , Watanabe D. H. , Schierman L. W.
Published: February 2007

Resistance to the development of progressively growing tumors induced by Rous sarcoma virus is a dominant trait controlled by a gene linked to the major histocompatibility complex (MHC). The effect of bursectomy (Bx) on the expression of this trait was studied in two inbred lines of chickens homozygous for different MHC alleles, and which differ with respect to the gene controlling resistance to Rous tumors. The results show that Bx alters the expression of the trait, since genetically resistant birds were rendered highly susceptible to progressive tumor growth. The bursa of Fabricius thus makes an important contribution to resistance. The results do not indicate whether genetic resistance is mediated exclusively by B cells or by another bursa‐dependent population.
Sequential use of hapten‐gelatin fractionation and fluorescence‐activated cell sorting in the enrichment of hapten‐specific B lymphocytes
Authors: Nossal G. J. V. , Pike B. L. , Battye F. L.
Published: February 2007

Spleen cells from normal unimmunized adult mice were subjected to a 2‐stage fractionation procedure designed to prepare a subpopulation highly enriched for the capacity to form antibody to the hapten fluorescein (FLU). First, the spleen cell suspension was rocked in a petri dish coated with a thin layer of FLU‐gelatin (15 min at 4 °C), the nonadherent cells washed away and the adherent cells recovered by melting the gelatin and treated with collagenase. The cells were relabeled with a fluorescent protein, usually FLU‐gelatin at 100 μg/ml, (25 °C, 15 min). After washing, the cells were sorted into cohorts of relatively homogeneous fluorescence intensity in the fluorescence‐activated cell sorter (FACS). Finally, the sorted cells were again collagenase‐treated and stimulated with FLU‐coupled polymerized flagellin in a limit dilution microculture system capable of generating single clones of anti‐hapten plaque‐forming cells (PFC).

It was found that the cohort of cells representing the 10 % most intensely fluorescent cells, yielded PFC clones with a frequency of 1 in 8, about 5 times higher than the hapten‐gelatin‐enriched cells. Less fluorescent cohorts gave progressively lower frequencies of clonable PFC precursors. Some evidence was obtained, suggesting that the most highly fluorescent cells produced antibody of higher median avidity than the FLU‐gelatin‐fractionated cells, which in turn showed higher avidity than unfractionated spleen cells, findings consistent with the clonal selection hypothesis.

Somewhat surprisingly, cells with high fluorescence intensity prepared by FACS sorting of FLU‐gelatin‐labeled unfractionated spleen cells, yielded much lower PFC precursor frequencies than cells of equivalent fluorescence intensity derived through the 2‐stage fractionation procedure.

Spleen cells from newborn mice were subjected to 2‐stage fractionation. The method proved equally applicable to them, and preparations with a 1 in 11 PFC precursor frequency could be readily generated. However, the neonatal cells differed from the adult cells in responding significantly better to the polyclonal B cell activator, lipopolysaccharide, than to antigen.

The theoretical implications of these findings and the potential uses of pure populations of hapten‐binding cells are briefly discussed.
Perturbation of lymphocyte response to concanavalin A by exogenous cholesterol and lecithin
Authors: Rivnay B. , Globerson Amiela , Shinitzky M.
Published: February 2007

Incubation of lymphocytes with lecithin liposomes enriched with cholesterol, elevated the cholesterol level of the cells relative to phospholipids. Treatment of lymphocytes with pure lecithin liposomes resulted in the converse effect. Both these treatments resulted in suppression of the induction phase of the response to concanavalin A and were practically reversible. It is suggested that these changes induce modulations of the fluidity of the lymphocyte membrane which may also take place in vivo by serum lipoproteins. Based on this study, the possible effects of lipids on lymphocyte activation are discussed.
Genetic definition of I region‐determined antigens of the rat major histocompatibility complex
Authors: Günther E. , Šmtark O. , Koch C.
Published: February 2007

A recombinant haplotype of the major histocompatibility complex (H‐1) of the rat has been found among F2 hybrids of two congenic strains, and it has been shown previously that the major gene determining mixed lymphocyte stimulation and the Ir‐TGAL and Ir‐PheGAL genes were separated from the genes determining the classical serologically detectable histocompatibility antigens. It has been shown that the complementing Ir‐HGAL genes mapped together with the other Ir genes, and this gene cluster is assumed to represent the I region of the rat. Serological analysis of the recombinant is interpreted as showing that the Ir genes do not map in‐between the genes controlling the classical histocompatibility antigens. Thus, the sequence of the major histocompatibility genes in the rat does not seem to follow that of the mouse H‐2 system. Reciprocal immunization between the recombinant and the parental strain which shares the classical transplantation antigens but differs for the Ir genes, led t o the production of antisera which detected antigens with restricted tissue expression. These antigens were predominantly found on B lymphocytes and not on liver, brain or red blood cells and thus resembled mouse Ia antigens. Strain distribution analysis revelaed extensive cross‐reactivity with most of the H‐1 haplotypes, and two private specificities could be operationally defined. Thus, it is now possible to genetically define Ia antigens in the rat by the use of I region‐congenic strains.
Antigen‐antibody complexes suppress antibody production by mouse plasmacytoma cells in vitro
Authors: Abbas A. K. , Klaus G. G. B.
Published: February 2007

Preformed complexes of 2,4‐dinitrophenylated keyhole limpet hemocyanin (DNP‐KLH) and anti‐DNP or anti‐KLH antibodies selectively, suppressed the production of anti‐DNP IgA by the plasmacytoma cell line, MOPC 315, in vitro. Complexes made with DNP8.5KLH (8.5 moles DNP/105 daltons carrier) inhibited the secretion of IgA but not its synthesis, whereas complexes prepared with the more highly substituted DNP20KLH inhibited synthesis as well. Moreover, complexes of DNP‐KLH and anti‐DNP F(ab′)2 fragments were as suppressive as those made with IgG antibodies, suggesting that the mode of presentation of antigenic determinants and not surface Fc receptors may play a major role in this phenomenon.
Surface immunoglobulin phenotype of murine spleen cells which form B cell colonies in agar
Authors: Scott D. W. , Layton Judith E. , Johnson G. R.
Published: February 2007

Separation of IgD‐bearing B lymphocytes from the spleens of 3‐week‐old or adult mice has been achieved using cellular affinity columns and an anti‐δ allotype serum. The results demonstrate that the majority of cells capable of forming B lymphocyte colonies in agar are δ‐positive although they lose detectable IgD upon stimulation. It is proposed that these cells are the descendants of IgD‐negative cells found in the fetal liver and neonatal spleen.
Selective reduction and proteolysis in the hinge region of liganded and unliganded antibodies. Identical kinetics suggest lack of major conformational change in the hinge region
Authors: Wright J. K. , Engel J. , Jaton J.‐C.
Published: February 2007

The experiments described here were designed to test the validity of the allosteric immunoglobulin model of Huber et al. (Nature 1976. 264: 415) according to which antigen could cause a stiffening of the flexible antibody molecule by the formation of longitudinal CH1–CH2 interdomain contacts. The largest structural change would involve the folding of the hinge peptide in‐between the CH2 globules. Consequently, the accessibility of the hinge region to reduction and limited proteolysis should be considerably altered.

Homogeneous rabbit antibodies to type II and III pneumococcal polysaccharide were reacted with corresponding oligosaccharide haptens and whole polysaccharide antigens to form monomeric and polymeric IgG antibody complexes, respectively. Reduction of the inter‐heavy chain disulfide bond in the hinge region by a series of thiol reagents of increasing size and polarity was performed; the ratio of reduction rate in complexes with hapten or antigen compared to that of hapten‐or antigen‐free control was found to be close to unity, thus indicating that the susceptibility of the hinge disulfide bond was unaffected by the binding of hapten or antigen. Limited proteolysis in the hinge region of immune complexes by activator‐free papain or pepsin in the absence of reducing agent was carried out, and the appearance of antibody fragments followed by sodium dodecyl sulfate gel electrophoresis. The rate of proteolysis in hapten‐antibody complexes and in large soluble antigen‐antibody aggregates (16–29 S) did not show any significant decrease when compared to that for unliganded antibody.

The identity of the reduction and proteolysis rates in the presence and absence of antigen provides strong evidence for the lack of a major conformational change in the hinge region upon antigen binding.
Allelic exclusion in the B lineage cells of the rabbit
Authors: Loor F. , Kelus A. S.
Published: February 2007

Allelic exclusion of the k polypeptide chain allotypes b4 and b5 of the rabbit exists for the immunoglobulins of almost all plasma cells and of most mature small B lymphocytes. However, both these alleles are expressed simultaneously in rare plasma cells and in an usually large fraction of the lymphoid cells of the bone marrow. Our experiments support the idea that such bone marrow B lineage cells do not always show allelic exclusion.
Stimulation of murine B lymphocytes to IgG synthesis and secretion by the mitogens lipopolysaccharide and lipoprotein and its inhibition by anti‐immunoglobulin antibodies
Authors: Andersson J. , Coutinho A. , Melchers F.
Published: February 2007

The two mitogens, lipopolysaccharide (LPS) and lipoprotein (LP), both stimulate to an equal extent murine B lymphocytes to develop IgG‐synthesizing and IgG‐secreting cells. IgG synthesis and secretion was detected either by biosynthetic labeling of stimulated B cells, followed by immunoprecipitation and polyacrylamide gel electrophoresis of labeled Ig, or by the protein A plaque assay detecting all IgG‐secreting cells with IgG‐specific developing antisera. B cells from spleen, lymph node, thoracic duct and fetal liver of normal and T cell‐deficient nu/nu mice are all stimulated by the two mitogens to develop IgG‐secreting cells. Mitogen‐induced IgG secretion, therefore, can occur independently of T cells and of external antigen.

Anti‐Ig antibodies inhibit the mitogen‐induced development of Ig‐secreting cells. Antibodies with specificities for μ chains when added before or soon after mitogenic stimulation of small, resting B cells, will inhibit these cells from developing into IgG‐secreting cells. Later in culture, antibodies with specificities for γ chains also become inhibitory for the mitogen‐induced development of IgG‐secreting cells. These results indicate that the precursors of the IgG‐secreting cells carry IgM in the outer surface membrane. They also suggest that during mitogen‐stimulated growth of B cell clones, IgG becomes expressed in the surface membrane in a functional way which allows the inhibition of mitogen‐induced IgG secretion by anti‐γ antibodies.
Antigen presentation in the murine T lymphocyte proliferative response. II. Ir‐GAT‐controlled T lymphocyte responses require antigen‐presenting cells from a high responder donor
Authors: Yano A. , Schwartz R. H. , Paul W. E.
Published: February 2007

The activation of T lymphocytes from poly (Glu60Ala30Tyr10)n (GAT)‐primed donors by GAT‐pulsed nonimmune spleen cells was shown to require identity at the I‐A subregion of the major histocompatibility complex. However, GAT‐primed T lymphocytes from (responder × nonresponder) F1 hybrids could only be stimulated to proliferate by GAT bound to high responder or F1 spleen cells but not by GAT bound to spleen cells from the low responder parent. The failure of spleen cells from low responder parental strains to present GAT was shown not to be due to the presence of suppressor cells in either the antigen‐presenting or the responding cell populations. These results indicate that control of antigen‐presenting cell‐T lymphocyte interactions is one site of Ir gene expression.
The effects of α and β adrenergic agents on spleen cell antigen binding in four amphibian species
Authors: Hodgson Ruth M. , Clothier R. H. , Ruben L. N. , Balls M.
Published: February 2007

Adults of two urodele amphibian species (Triturus cristatus carnifex and Cynops hongkongensis) and two anuran species (Rana temporaria and Xenopus laevis laevis) were immunized with a 25 % suspension of sheep or horse erythrocytes.

After eight or 14 days, splenic lymphocytes were removed, and their specific red cell‐binding capacities tested by immunocytoadherence. Antigen‐binding cells were classified as high‐dose nonsecretory (S−) or secretory (S+), according to whether they bound a single layer or several layers of erythrocytes.

The stimulation of both α and β adrenoreceptors reduced the numbers of S+ rosettes formed by Triturus and Cynops lymphocytes, whereas a β agonist increased and an α agonist decreased S+ rosette formation by Rana and Xenopus splenic lymphocytes. These effects were blocked by α and β adrenoreceptor antagonists.

Low‐dose immunization of Xenopus with a 0.0025% suspension of sheep erythrocytes gave a minimal number of S+ rosettes two and eight days after immunization, and β adrenoreceptor stimulation had no effect on antigen binding.

These results are discussed in terms of the distribution of α and β adrenoreceptors in amphibians and possible relationships between S+ and high‐dose S− antigen‐binding cells, and support the view that functional lymphocyte heterogeneity exists in these lower vertebrates.
T cell‐dependent suppression of antibody production. I. Characteristics of suppressor T cells following tolerance induction
Authors: Basten A. , Miller J. F. A. P. , Loblay R. , Johnson P. , Gamble Jennifer , Chia Eunice , Pritchard‐Briscoe Helen , Callard R. , McKenzie I. F. C.
Published: February 2007

Specific immunological tolerance was induced in adult CBA mice by a single injection of deaggregated human IgG (dHGG). Spleen cells taken 7 to 42 days later, produced consistent suppression of a DNP‐HGG collaborative antibody response on adoptive transfer into heavily irradiated recipients. Noncentrifuged F(ab')2 fragments of HGG were as effective as dHGG in the production of suppressor cells. Suppression was antigen‐specific since HGG‐tolerant cells failed to abrogate either a DNP‐keyhole limpet hemocyanin collaborative response or antibody production to the noncross‐reactive antigen, horse erythrocytes. Pretreatment of the tolerant cell population with anti‐Thy‐1 serum and complement reversed the suppressive effect. However, purified tolerant T cells obtained by passage through nylon wool or anti‐Ig columns were less effective than the original spleen cells in mediating suppression. Analysis of the cell types appearing in the column effluents indicated that the reduction in suppressive activity is best explained by retention of T cells rather than macrophages. Different T cell populations, however, were retained on the two types of columns. In the case of anti‐Ig columns, these consisted of Ly‐2,3+, Ia+ effector cells, whereas nylon wool columns caused depletion of Ly‐1,2,3+ cells which are known to act as amplifiers of suppression.

Suppression could not be explained in terms of delay in differentiation of antibody‐forming cell precursors since the effect persisted for up to 15 days after transfer of tolerant cells. The demonstration of a reduction in serum anti‐DNP and anti‐HGG antibodies excluded the possibility of antibody production in sites other than the spleen. A role for anti‐carrier antibody‐antigen complexes in mediating the effector phase of suppression was rendered unlikely by the finding that the suppressive effect of tolerant cells persisted in the absence of detectable anti‐HGG antibody production.

Effector T cells mediating suppression in this system were shown to bear the phenotype Ia+, Ly‐2,3+ as judged by the effect of pretreatment with appropriate antisera and complement. They were spleen‐seeking, but were not detected in the thymus or recirculating lymphocyte pool. Adult thymectomy failed to cause a significant reduction in suppressive activity by tolerant spleen cells indicating that at least a major component of the immediate precursors is not of recent thymic origin.
Variable region correlates of group b allotypes: amino acid sequence studies of b9 L chains from homogeneous antibodies
Authors: Fraser B. A. , Thunberg A. L. , Kindt T. J.
Published: February 2007

The amino acid sequence was determined for residues 1 to 88 and residues 110 to 147 for a rabbit light chain (4153‐I) with allotype b9 from a homogeneous anti‐streptococcal antibody. The amino acid sequence of the L chain from a second antibody (4153‐II) was also determined for residues 1 to 49 and 62 to 77. In spite of the large differences in constant region sequence between b4 and b9 L chains, the variable regions of these antibodies are quite similar to those reported for b4 L chains. Both chains bear a b9‐specific substitution (glutamic acid) at position 16. The 4153‐I chain also has substitutions at positions 70 and 81 that may be exclusive to variable regions of the L chains with the b9 allotype. These allotype‐associated VL structural differences offer support to the notion that structural genes for the CL region are either linked to distinct VL gene complexes or that certain V regions are expressed only in concert with certain CL regions.