bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphocyte stimulation by protein A of Staphylococcus aureus
Authors: Forsgren A. , Svedjelund A. , Wigzell H. 
Published: February 2007

AbstractProtein A from Staphylococcus aureus (SpA) is known to bind to the Fc region of most mammalian IgG classes. In the present article data are presented showing that SpA is a highly efficient mitogen for human peripheral B lymphocytes, with no detectable activity for T lymphocytes. In order to achieve optimal stimulating conditions SpA should be presented to the lymphocytes on an insoluble matrix, such as the SpA‐positive bacteria themselves or SpA covalently attached to Sephadex or Sepharose beads. Using such conditions SpA is equivalent with regard to stimulatory capacity for B lymphocytes as phytohemagglutinin is for the human T lymphocytes. Specificity controls proved beyond doubt that SpA and not any other contaminating product is the B cell mitogen.It is concluded that SpA as an inducer of human B lymphocyte division might serve as a highly useful assay in the clinical assessment of B lymphocyte function. It should also be a suitable tool in the fine analysis of B lymphocyte activation via the specific interactions with surface IgG molecules.
Studies on the activation of mouse bone marrow‐derived macrophages by the macrophage cytotoxicity factor (MCF)
Authors: Meerpohl H.‐G. , Lohmann‐Matthes Marie‐Luise , Fischer H. 
Published: February 2007

AbstractThe capacity of bone marrow‐derived macrophages to be rendered cytotoxic by macrophage cytotoxicity factor (MCF) at different stages of maturation was tested. Under in vitro conditions not only mature macrophages but also nonadherent precursor cells were successfully activated. Mature adherent bone marrow macrophages can be rendered cytotoxic for up to three weeks in tissue culture. Cytotoxic effects are demonstrable even at a killer target ratio of 0.5: 1. Granulocytes do not respond to activation with MCF. Bone marrow‐derived macrophages can be collected at early stages of maturation, when they grow in suspension or have developed only loose adherence. Macrophages which have differentiated in vitro from bone marrow never show any signs of nonspecific activation as measured by our cytotoxic assay system.
Stimulation of lymphocytes by allogeneic lymphocytes and lymphoblasts in the presence of anti‐HLA antisera
Authors: Corley R. B. , Dawson J. R. , Amos D. B. 
Published: February 2007

AbstractAnti‐HLA alloantisera inhibit mixed lymphocyte responses in which normal lymphocytes are used as stimulator cells. These same antisera are unable to inhibit lymphocyte proliferative responses stimulated by lymphoblastoid cells from cultured lymphoid cell lines. They also fail to inhibit either the generation of cytotoxic effector cells by lymphoblastoid cells or lymphocyte‐mediated cytotoxicity against the lymphoblasts. Although the number of HLA antigens on the surface of lymphoblasts is reported to be greater than on normal lymphocytes, the failure of alloantisera to inhibit lymphoblast‐induced responses in vitro does not appear to be due to insufficient amounts of antiserum to react with the antigenic sites. Rather, the data are interpreted to suggest that antigens which are not HLA and are not closely associated with HLA on the lymphocyte membrane are responsible for the stimulation of allogeneic lymphocytes by lymphoblastoid cells.Although lymphoid cell lines are known to contain the genome of the Epstein‐Barr virus, antisera against products of the viral genome fail to inhibit proliferative responses to lymphoblastoid cells, suggesting that these antigens do not directly participate in lymphocyte activation.
Selective breeding of mice for antibody responsiveness to flagellar and somatic antigens of Salmonellae
Authors: Siqueira Maria , Bandieri A. , Reis Moema S. , Sant'anna O. A. , Biozzi G. 
Published: February 2007

AbstractSelective breeding has been performed in mice for their high or low antibody responsiveness to Salmonella antigens (Ag). Two noncross‐reacting Salmonellae (S. typhimurium and S. oranienburg) have been alternately used to immunize successive generations in order to avoid interference of maternally transmitted antibody. Both Salmonellae carry two independent antigens: flagellar (f) and somatic (s). Two two‐way selections were carried out: one for agglutinin response to fAg and the other for agglutinin response to sAg (Selection Ags). The agglutinin response to the other independent Ag was also measured (Associated Ags). The phenotypic character chosen for selection is the maximal agglutinin titer in response to optimal immunization.In both selections, high and low responder lines diverged progressively. There was a 27‐fold interline difference in the F13 generation of selection for fAg response and a 38‐fold one in the F11 generation of selection for sAg response. This divergence and the continuous distribution of phenotypes in the foundation population indicate that the quantitative character investigated is subject to polygenic regulation. The realized heritability (h2) of the character, measured from the interline divergence, was 0.18 ± 0.06 in both f and s selections. This means that about 20 % of the phenotypic variance of the foundation population is additive.The modification of immune responsiveness to the selection Ag produced by selective breeding was accompanied by a parallel and equivalent effect on immune responsiveness to the noncross‐reacting Associated Ag. This effect is therefore entirely nonspecific. A small but definite sex effect in favor of female antibody responsiveness was demonstrated.The results are discussed in comparison with other selection experiments made in mice for quantitative antibody response to other antigens.
Control mechanism of lymphocyte traffic. Altered distribution of 51Cr‐labeled mouse lymph node cells pretreated in vitro with lipopolysaccharide
Authors: Freitas A. A. , de Sousa Maria 
Published: February 2007

AbstractThe effect of in vitro treatment of mouse lymph node cell populations with lipopolysaccharide (LPS) on their migration in syngeneic recipients was studied.LPS‐exposed cells had a decreased lymph node localization and an increased spleen distribution when compared to control untreated cells, after intravenous injection into syngeneic recipients. This effect of LPS on cell traffic was maximal at 24 h and could not be detected at either 1 or 72 h after cell transfer.These changes induced on cell distribution by LPS treatment are interpreted as the consequence of a modified interaction between the circulating lymphocytes and the resident cells within the spleen of the recipients.
The antigen‐inexperienced thymic suppressor cells: a class of lymphocytes in the young chicken thymus that inhibits antibody production and cell‐mediated immune responses
Authors: Droege W. 
Published: February 2007

AbstractTransfer of thymus cells from young chickens in combination with a light whole body irradiation (360 R) was found to suppress the rejection of skin grafts across strong histocompatibility (B) differences. On the average, the suppressed animals also showed decreased serum hemagglutinin titers against erythrocytes of the skin donor strain and a decreased graft‐versus‐host (GvH) reactivity against embryos of this strain.The thymic suppressor cells can be obtained from animals that have not experienced the antigen under test. However, after transfer and contact to the antigen (skin graft) they can lead to the formation of specific (“activated”) suppressor cells and can mediate in the long run a specific inhibition of the response to this antigen.The suppressive activity is associated with a bursa‐dependent cellular subpopulation in the thymus that is different from B lymphocytes, B precursor cells or GvH‐reactive T cells. The bursa dependency of the thymic suppressor cell suggests that functionally different lineages of thymic and thymus‐derived lymphocytes are derived from different sources of prethymic stem cells. The suppressor cells are predominantly found in the young chicken thymus and already detectable in the 16‐day‐old embryo, while poor suppressive activity is found in the adult thymus.The suppressive effect can be obtained with thymus cells from either syngeneic or allogeneic donors. Embryonic allogeneic donors provide suppressive cell preparations free of GvH reactivity.The possibility that the thymus suppressor cells mediate self tolerance and “neonatal tolerance” is discussed.
Fusion between immunoglobulin‐secreting and nonsecreting myeloma cell lines
Authors: Köhler G. , Howe S. C. , Milstein C. 
Published: February 2007

AbstractThe defects in two nonsecreting variant clones of the mouse plasmacytoma MOPC 21 (P3) were studied by tissue culture methods. The variants (NSI and NSIII) do not synthesize detectable heavy chains. NSI synthesizes, but does not secrete, light chains and NSIII does not synthesize light chain.A screening procedure was used allowing the detection of revertant cells secreting immunoglobulin. The method is based on a hemolytic plaque assay using anti‐immunoglobulin‐coated red cells. No revertants were detected among 2 × 107 cells. Both variant lines were fused to another myeloma line (PI) which secretes a complete immunoglobulin and excess light chains. Analysis of the products by isoelectric focusing showed that in the hybrids there was no reactivation of synthesis of the nonexpressed chains. The defects leading to loss of synthesis cannot therefore be complemented in the hybrid lines.The secretion of light chain in NSI, on the other hand, could be complemented in the hybrid but the light chain was only secreted as part of a new immunoglobulin hybrid molecule.
B cell tolerance induced by polymeric antigens V. Different avidities of primed and virgin precursor cells for paucivalent antigen
Authors: Willcox H. N. A. , Klaus G. G. B. 
Published: February 2007

AbstractWe have compared the avidity of virgin and primed hapten‐specific precursor cells for DNP‐lys‐S3 (dinitrophenylated type 3 pneumococcal polysaccharide) by measuring its capacity to prevent them from binding highly radioactive DNP‐hemocyanin, and thereby protect them from committing hapten‐specific “suicide”.Moderately substituted conjugates (e.g. DNP‐2.7S3) protected virgin and memory B cells impartially. In contrast, DNP‐lyso0.6S3 protected memory cells efficiently, but protected virgin cells only at considerably higher concentrations.These results are consistent with previous evidence – from this and other systems – that there is a higher density of receptors on primed than on unprimed B cells – the significance of which is discussed.
Inheritance of antibody specificity. The IgM anti‐lipopolysaccharide response in mice
Authors: Pauli R. Di 
Published: February 2007

AbstractMice of different genotypes were immunized with Salmonella anatum. The cross‐reactivity patterns of their IgM anti‐S. anatum lipopolysaccharide (LPSAN) antibodies were characterized by their relative avidity toward heterologous LPS.When the LPS from S. cholera suis (LPSCHS) was used as the heterologous LPS, clear differences between mouse strains were found. DBA/2 and DBA/1 showed cross‐reacting IgM, whereas C57BL/10, C57BL/6, BALB/c‐Igb and B10.D2 had mainly noncross‐reacting IgM. In C3H and C57BL/6‐Iga, individual mice express either the cross‐reacting or the noncross‐reacting antibodies.The IgM antibodies from individual mice were further characterized for their cross‐reactivity toward the LPS from S. strasbourg (LPSSTR) and S. illinois (LPSILL). Only individual patterns with no correlation to the cross‐reactivity pattern with LPSCHS were found. This shows that more than one antibody type is characterized by cross‐reactivity.(B 10.D2 × DBA/1)F1 mice showed a biphasic distribution of cross‐reactivity. Of the F1 x DBA backcross mice 21 % had IgM antibodies which showed no cross‐reaction with LPSCHS. This still is in agreement with one locus controlling this phenotype.This locus segregates independently from Ig allotype since no correlation was found between allotype and cross‐reactivity pattern in F1 x DBA backcross mice.
The immunological properties of haptens coupled to thymus‐independent carrier molecules. IV. The IgG response to dinitrophenylated Ficoll
Authors: Klaus G. G. B. , Phillips Jennifer M. , Humphrey J. H. , Dresser D. W. , Cross Anne M. 
Published: February 2007

AbstractDinitrophenylated polysucrose (DNP‐Ficoll) elicits T cell‐independent IgM anti‐DNP antibody formation in mice. This antigen also elicits a heterogeneous IgG1 and IgG2 anti‐DNP response, which is operationally as T‐independent as the IgM response. However, a concomitant graft‐versus‐host reaction markedly enhances the IgG response (allogeneic effect). These results confirm those of others, indicating that a certain proportion of the precursors of IgG‐producing cells can be triggered by some T‐independent antigens. However, our results suggest that even with such antigens optimal triggering of IgG precursors requires T cell help.
Demonstration that IgG memory is carried by IgG‐bearing cells
Authors: Okumura K. , Julius M. H. , Tsu Theta , Herzenberg Leonore A. , Herzenberg L. A. 
Published: February 2007

AbstractMemory B cells which give rise to JgG antibody‐producing cells were generally assumed to be IgG‐bearing cells. However, recent studies indicating that very few IgG‐bearing cells exist in lymphoid tissue brought this assumption into question. In this study, we examined directly the question whether IgG‐bearing cells contain functional precursors of IgG antibody‐producing cells. Using the adoptive secondary immune response, we demonstrated that Ig‐1b‐bearing cells, isolated with the fluorescence‐activated cell sorter (FACS), are the functional precursors of Ig‐1b‐producing cells. Further, we have enriched IgG2 and IgG1 memory B cells using the FACS. The results show that IgG2‐bearing cells are the functional precursors of the IgG2 antibody‐producing cells. Likewise, the IgG1‐bearing cells are the functional precursors of IgG1 antibody‐producing cells. Thus, IgG memory cells have surface IgG which indicates the class and allotype commitment of the memory cell and its progeny antibody‐forming cells.
Effect of anti‐carrier antibody on carrier‐determined tolerance
Authors: Terres G. , Aldo‐Benson Marlene , Borel Y. 
Published: February 2007

AbstractThese experiments were originally designed to determine whether an anti‐carrier antibody, e.g., anti‐allotype could break hapten‐specific tolerance in vivo. Tolerance to 2,4‐dinitrophenyl (DNP) was induced in C57BL/6J mice using DNP‐BALB/c IgG2a conjugate. When anti‐allotype serum was injected in C57BL/6J mice one day after a single injection of DNP‐IgG2a the mice were not tolerant. In contrast, when tolerance was induced by four weekly injections of tolerogen, the anti‐allotype serum had no effect on the tolerant state. This effect was specific for tolerance‐inducing carrier.Anti‐carrier antibody injected in C57BL/6J mice one day after DNP‐IgG2a produced a small but significant anti‐DNP response without administration of the immunogen, whereas the tolerogen (DNP‐IgG2a) by itself was not immunogenic. Similarly, despite multiple injections of DNP‐IgG2a, bearing the foreign allotype, only one out of 7 C57BL/6J mice showed a weak anticarrier response. In contrast, a marked anti‐carrier (IgG2a) response was obtained when the anti‐allotype antibody was passively administered in C57BL/6J mice.In conclusion, these experiments suggest that tolerance to an antigenic determinant may be broken by an antibody directed not to this determinant, but to another on the same molecule. The significance of this finding in relationship to the mechanism of the carrier‐determined tolerance and the breakdown of self‐tolerance is discussed.
Human T cell receptor for IgM: specificity for the pentameric Fc fragment
Authors: Ferrarini M. , Moretta L. , Mingari Maria C. , Tonda P. , Pernis B. 
Published: February 2007

AbstractThe specificity of the IgM receptor expressed by human T cells cultured in IgM‐free media has been investigated. IgM receptors have been detected using a rosette system with ox erythrocytes coated with rabbit antibody (EA(IgM)), and the inhibitory capacity of different IgM fragments in the rosette system has been tested. It was found that F(c)5μ but not F(ab′)2μ, nor monomeric IgM (8 S IgM) inhibited EA(IgM) rosette‐forming cells. This indicates that the receptor present on the surface of T cells has affinity for a structure located in the Fc portion of the pentameric IgM.
Specific enrichment of antigen‐binding receptors from sensitized murine lymphocytes
Authors: Krawinkel U. , Rajewsky K. 
Published: February 2007

AbstractSplenic T and B lymphocytes from sensitized mice were adsorbed to antigen‐coated nylon discs and released from the discs by temperature shift as described by Kiefer, H., (Eur. J. Immunol. 1973. 3: 181 and 1975. 5: 624). After cell release, lymphocyte‐derived antigen‐binding material could be recovered from the discs. A major fraction of the activity (70–80%) binds to anti‐immunoglobulin immunosorbents. A minor fraction does not detectably cross‐react with γ, μ, α and k immunoglobulin poly‐peptide chains. When filtrated through Sephadex G‐200, the bulk of activity of both fractions elutes in the region of 7 S serum antibody. However, as demonstrated for (4hydroxy‐3‐nitro‐phenyl)acetyl (NP)‐binding material from C57BL/6 lymphocytes, the average affinity for antigen of the two fractions is drastically lower than that of humoral antibody, and the average affinity of the minor fraction is lower than that of the major fraction.The fraction of lymphocyte‐derived antigen‐binding material that does not adsorb to insolubilized anti‐immunoglobulin serum was found to be proportional to the fraction of T lymphocytes in the input cell population and may therefore represent antigen‐binding T lymphocyte surface receptors.
Genetic control of the immune response to the radom linear terpolymer of L‐glutamic acid, L‐lysine and L‐leucine (GLleu) by complementing Ir genes
Authors: Dorf M. E. , Twigg Martha B. , Benacerraf B. 
Published: February 2007

AbstractThree levels of humoral responsiveness (none, high or marginal) were noted following secondary immunization with the random linear terpolymer of L‐glutamic acid, L‐lysine and L‐leucine (GLleu). These immune responses were under dual H‐2‐linked Ir gene control. Gene complementation was observed in appropriate F1 offspring between two nonresponder strains and in selected intra‐I region recombinants derived from crossing over between nonresponder parental haplotypes. One of the Ir‐GLleu genes, β, was localized within the I‐A or I‐B subregions. The other Ir‐GLleu locus, termed a, was mapped in the I‐C or S subregions. Differences in the strain distribution of immune responsiveness to GLleu and a related terpolymer GLphe (which is also under complementing Ir gene control) are primarily attributable to differences among the Ir‐GLleu and Er‐GLphe β alleles. A correlation exists between the presence of the Ir‐GLleu α(+)allele and the gene coding for specificity Ia.7.
Rabbit antibody light chains: selective breeding narrows variability in framework and complementarity‐determining residues
Authors: Braun D. G. , Huser H. , Riesen W. F. 
Published: February 2007

AbstractThe amino acid sequence of 5 light (L) chain (b4)variable (VL) regions and the partial sequence of VL (K) regions from 12 anti‐streptococcal group A‐variant polysaccharide (Av‐CHO) and 2 anti‐streptococcal group C polysaccharide (C‐CHO) antibodies was determined. These sequences contain 70 invariant positions as opposed to 50 invariant positions in other rabbit VL regions. Variability within the framework residues lacks randomness, and parent offspring relationship or otherwise close familial relationship is apparent in several instances. Variability in the complementarity‐determining regions is reduced by 2.3–5.5‐fold in comparison with other rabbit L‐chains with several identical first and third hypervariable regions. Residue positions 50‐56, known to mark the second hypervariable region in human K‐chains, are not hypervariable in L‐chains from Av‐CHO rabbit antibodies. Considering the 67 rabbit L‐chain sequences, completely or partially known today, for counting the number of V region germ line genes, it is concluded that the species rabbit has at least 27 VL germ line genes available.
Immunosuppressive activity of submaxillary gland extracts of the mouse 1. Effect on antibody formation in response to sheep red blood cells
Authors: Koch Judith H. , Rowe Janet 
Published: February 2007

AbstractAqueous extracts of mouse submaxillary glands yield six peaks on Sephadex G‐75 columns, each containing several molecular species. Two of these fractions (III and IV) have a profound effect on the immune response.When given a day before immunization with sheep erythrocytes, the number of antibody‐producing cells is reduced ten‐fold or more, and the switch from IgM to IgG is virtually absent. Administration two days before or on the day of immunization results in about 50 % depression; outside this range there is no effect.The dose‐response curve is of sigmoidshape, with the median at about 0.5 mg of fraction III/40 g mouse, reaching an asymptote after doses of ⩾ 5 mg at about 5 % of the response of untreated mice.Depression of the primary response does not prevent the development of immunological memory: the secondary response is typical in the early and predominant appearance of IgG‐producing cells, although their numbers are somewhat lower than in the controls which received no treatment before primary immunization. Treatment on the day before boosting abrogates the secondary response.The immunotranquillizer from mouse submaxillary glands acts equally well on syngeneic and allogeneic recipients, affecting the earliest stage of the immune response. The results are compatible with the induction of a temporary block in the development of helper T cells.
A plaque assay for all cells secreting Ig of a given type or class
Authors: Gronowicz Eva , Coutinho A. , Melchers F. 
Published: February 2007

AbstractA modification of the hemolytic plaque assay using protein A‐coated red cells is described which makes use of the fact that the Fc portion of IgG binds to protein A. A number of murine plasmacytomas secreting different classes of Ig have been tested for plaque formation with these indicator red cells. In the presence of complement‐binding antibodies specific for the corresponding class of secreted Ig, between 10 and 70 % of all plated myeloma cells formed plaques. The assay shows a prozone effect in excess of antibody, suggesting that complexes of antibody and secreted Ig effect lysis of the target cells. This assay can be used to enumerate cells secreting any molecules for which complement‐binding antibodies are available.
Generation of cytotoxic cells in absence of blastogenesis by mouse leukemic cells in mixed cultures
Authors: Collavo D. , Biasi G. , Colombatti A. , Chieco‐Bianchi L. 
Published: February 2007

AbstractPrimary virus‐induced murine leukemias and transplantable leukemic cell lines, originally induced by virus, chemical or physical agents, failed to stimulate normal spleen cells differing at the H‐2 complex or at M1s locus in the one‐way mixed leukocyte culture. Lack of stimulation seems at least partially due to a nonspecific inhibitory effect since in a “three‐party” culture system the leukemic cells interfered with the mixed leukocyte reaction (MLR) of normal allogeneic cells. Characterization of the leukemic cell populations used, according to their T or B cell origin, disclosed that in most cases T cell markers were present. Also, no Ia antigens were detected on leukemic cells. Furthermore, using a 51Cr release assay, leukemic cells could sensitize allogeneic normal lymphocytes to kill specifically normal as well as leukemic targets, even when no MLR was detected in parallel cultures.