bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maturation of mitogen‐activated bone marrow‐derived lymphocytes in the absence of proliferation
Authors: Andersson J. , Melchers F. 
Published: February 2007

AbstractMouse B lymphocytes respond by increased rates of DNA synthesis 14–24 hours after stimulation with the mitogen lipopolysaccharide. If, at this time, stimulated cells are treated for 12 hours with a “hot pulse” of thymidine, subsequent mitogen‐induced maturation to high rate IgM‐producing plaque‐forming cells is abolished. Thus, B cells stimulated by mitogen to mature also incorporate thymidine into DNA and proliferate.DNA synthesis is inhibited to 99 % in 48‐hour mitogen‐stimulated B lymphocytes by 10−2 M hydroxyurea or 10−3 M cytosine arabinoside, while protein and IgM synthesis and secretion and the plaque‐forming capacity of those cells are unaffected. When hydroxyurea is added to small, resting B cells at the time of initiation of mitogenic stimulation, these cells mature to 19 S IgM‐ secreting, plaque‐forming cells in the absence of DNA synthesis and proliferation. Maturation in the absence of DNA synthesis is also manifested by an increase in ratios of rates of synthesis and secretion of IgM over those of all proteins in the cell and by the attachment of the “branch” sugars, galactoses and fucoses, to 19 S IgM secreted by the cells. This maturation of B cells in the absence of DNA synthesis occurs within 12 to 30 hours after stimulation and is mitogen dose dependent. The inhibition of B cells to synthesize DNA and to develop into clones of plaque‐forming cells can be reversed by the removal of hydroxyurea for as long as 36 hours after mitogenic stimulation in the presence of the inhibitor.In the presence of hydroxyurea, B cells are stimulated to immature plasmablast‐like cells containing surface‐bound and little intracytoplasmic Ig within 16 to 24 hours of stimulation. Mature plasma cells containing no detectable surface‐bound Ig, but abundant intracytoplasmic Ig are only developed in the uninhibited, but not in the hydroxyurea‐inhibited mitogen‐stimulated cells later in the response. Thus, two stages of B cell maturation and differentiation can be distinguished: the first stage of an immature plasmablast develops in the absence of DNA synthesis, while the later stage of the development of the mature plasma cell requires DNA synthesis.
Genetic determination of tuberculin hypersensitivity in chicken inbred lines
Authors: Karakoz I. , Krejči J. , Hála K. , Blaszczyk Barbara , Hraba T. , Pekárek J. 
Published: February 2007

AbstractA dominant inheritance of the ability of CB line chickens to react to tuberculin over the inability of the WB line to develop this type of immune reaction was observed. The tuberculin reactivity in this line seems to be determined by one locus and is associated with the B locus.The involvement of the B locus in the regulation of tuberculin reactivity in other inbred lines of chickens is supported by the reactivity of the CA. IB (N6F2) birds in which the B allele of the IB line was introduced into the CA genotype. The CA. IB (N6F2) chickens manifest strong tuberculin sensitivity, corresponding to the type of reaction of the IB line, not to the weaker type of response of the CA line. The intensity of the tuberculin reaction of the CA and CC lines resembles that of the CB line, but the proportion of nonreactive birds is higher in these two lines than in CB chickens.
Studies of hyperimmune restricted and partially restricted anti‐pneumococcal polysaccharide antibodies from allotype‐defined pedigreed rabbits. II. Allotypes and idiotypes in sera and electrofocused fractions
Authors: Mage Rose G. , Pincus J. H. , Alexander C. , Freedman M. H. 
Published: February 2007

AbstractThe expression of allelic forms of immunoglobulin during immunization of heterozygotes with pneumococcal vaccines was monitored using anti‐allotype antisera specific for the genetically different forms of rabbit kappa chains (b‐locus allotypes). We also used the a‐locus (VH) allotypic markers of rabbit heavy chains and idiotypic determinants associated with a restricted subpopulation of anti‐polysaccharide antibodies of an individual rabbit. Analysis of fractions obtained by preparative liquid isoelectric focusing (IEF) of antisera from heterozygous rabbits exhibiting restricted antibody responses to type 3 or type 8 pneumococcal polysaccharides, indicated an enrichment for one a or b locus allotype. Enrichment of a specific idiotype from ∼ 11 % in the starting serum up to as high as 65 % in a focused fraction was also obtained. The method of preparative liquid IEF can thus be used to isolate antibodies restricted in allotype and idiotype from antisera. The quantities obtained are sufficient for further chemical and immunological study.
Chemical analysis and electron microscopy studies of human C1q prepared by different methods
Authors: Knobel H. R. , Villiger W. , Isliker H. 
Published: February 2007

AbstractFive differently isolated and purified human C1q preparation were examined by electron microscopy and analyzed by polyacrylamide gel electrophoresis in 0.1 % sodium dodecyl sulfate and 0.5 M urea. The amino acid and carbohydrate composition of C1q purified by the DNA method are reported and compared with results obtained ion C1q isolated by other procedures.Electron microscopy showed that all C1q preparation had six peripheral subunits connected by fibrillar strands to a central subunit. The presence of small amounts of dimers was also observed. The physico‐chemical properties of the molecule are independent of the purification method used. The five C1q preparation labeled with 125I in presence of lactoperoxidase formed two types of noncovalently linked subunits. In each case the smaller (central) subunit contained over thirty times as much radioactivity as the larger (peripheral) subunit supposed to interact with immune complexes. Reduction adn alkylatin confirmed for each preparation the presence of three polypeptide chains, the smaller of which contained essentially all radioactivity.
Five types of lymphocytes (lg− θ−, lg− θ+ weak, lg− θ+strong, lg+ θ− and lg+ θ+) characterized by double immunofluorescence and electrophoretic mobility Organ distribution in normal and nude mice
Authors: Roelants G. E. , Loor F. , von Boehmer H. , Sprent J. , Hägg Lena‐Britt , Mayor Kathleen S. , Rydén Aina 
Published: February 2007

AbstractThe simultaneous detection of Ig and θ on the surface of mouse lymphocytes permits the detection of four cell types (Ig−θ−, Ig−θ+, Ig+θ−, and Ig+θ+) which also have distinct electrophoretic profiles. All types are present in variable proportions in all lymphoid organs studied. Results obtained in congenitally athymic nude mice and in T‐deprived mice define a new type of lymphocyte, the Ig−θ+weak. This cell is non‐recirculating, Ig−, with a low density of θ and a slow electrophoretic mobility. It is a candidate for a T‐committed prethymic cell.
Immunochemical and biochemical study of a human Fcμ fragment (μ‐chain disease)
Authors: Lebreton J. P. , Ropartz C. , Rousseaux J. , Roussel P. , Dautrevaux M. , Biserte G. 
Published: February 2007

AbstractAn abnormal protein, from a patient with μ‐chain disease has been studied: protein BUR. It is devoid of the F(ab″)2μ fragment; molecular weight determinations and immunological data identify the protein as a F(c)5μ fragment. Similarly, carbohydrate determinations and proteolysis experiments relate it to a Fcμ fragment. Nevertheless, the protein, which contains J‐chain, lacks the entire covalently bonded structure of the F(c)5μ fragment. C‐terminal analysis shows a tyrosine residue identical to the C‐termin amino acid of μ‐chains. Sequence of the N‐terminal region determined for 15 residues shows identity with sequence 338–352 and sequence 333–347 of two entire μ‐chains previously studied. The relation of BUR to other heavy chain disease proteins is discussed.
Effect of delayed addition of 2‐mercaptoethanol on the generation of mouse cytotoxic T lymphocytes in mixed leukocyte cultures
Authors: Engers H. D. , Macdonald H. R. , Cerottini J.‐C. , Brunner K. T. 
Published: February 2007

AbstractThe generation of mouse cytolytic T lymphocytes (CTL) in primary or secondary mixed leukocyte cultures (MLC) is greatly enhanced by the addition of 2‐mercaptoethanol (2‐ME) to the culture medium. This enhancement can be equally demonstrated with either reduced or oxidized 2‐ME. Addition of 2‐ME to MLC as late as 3 days after the initiation of the culture results in a peak CTL response which is nearly as high as the one in cultures containing 2‐ME throughout the 4 day‐incubation period. Quantitative analysis of the CTL response in MLC supplemented with 2‐ME on day 3 shows a 50‐fold increase in lytic activity within 24 h, suggesting that cell differentiation, in addition to proliferation, may be affected by this agent.
Mixed lymphocyte reactivity of human lymphocytes primed in vitro. I. Secondary response to allogenic lymphocytes
Authors: Fradelizi D , Dausset J 
Published: February 2007

AbstractIn order to study the mixed lymphocyte culture reactivity of human lymphocytes primed in vitro, a nucleopore culture chamber technique allowing human lymphocytes to be cultured for a period of at least twoweeks has been developed. During the primary culture period in nucleopore chambers, human lymphocytes were sensitized against mitomycin‐treated allogenic stimulating cells. It was shown that the stimulated lymphocytes underwent a blastogenic reaction and the results suggest a reversion to the state of small, resting, primed lymphocytes.In vitro primed lymphocytes displayed allogenic memory. This was characteristic of a secondary response, which is shown by the following: 1) acceleration, the peak of thymidine incorporation occuring on day 4, 2) specificity, the accelerated response was observed only when theprimed lymphocytes were confronted with the cell used for priming. Contact with a third party cell did not produce this kind of activation. 3) Amplitude; the peak DNA synthesis response was greater than that of unprimed lymphocytes cultivated for the same length of time.
Isolation on discontinuous gradients of bovine albumin of a subpopulation of human lymphocytes exhibiting precursor characteristics
Authors: Gatien J. G. , Schneeberger E. E. , Parkman R , Merler E 
Published: February 2007

AbstractPurified subpopulations of lymphocytes were obtained from discontinuous bovine serum albumin (BSA) gradients and by rosetting sheeperythrocytes (E) or EAC1‐3. Cells from layers 1 to 3 ofthe BSA gradient which failed to rosette with E were highly reactive with EAC1‐3 and with anti‐human IgM. Demonstrating a high spontaneous rate of DNA synthesis and primitive morphology, these cells responded to pokeweed mitogen, concanavalin A and alloantigens, but not to phytohemagglutinin or soluble antigens. Constituting from 0.5 % to 3.0 % of all lymphocytes from each of the tissues studied, these lymphocytes appear to represent an earlier stage in human lymphocyte development distinct from both T and B cells.
B cell tolerance induced by polymeric antigens. II. Effects of tolerance on hapten‐binding lymphocyte levels in primary and secondaryantibody responses
Authors: Klaus G. G. B. 
Published: February 2007

AbstractTolerogenic doses of hapten [2,4‐dinitrophenyl (DNP)]‐coupled type 3 pneumococcal polysaccharide (DNP‐lys2.5−S3) totally abolished the anti‐DNP rosetteforming cell (RFC) response to primary immunization with DNP‐hemocyanin in mice, while lightly substituted antigen (DNP‐lys0.6−S3) had little effect. Both antigens suppressed secondary anti‐DNP RFC responses to DNP‐KLH. Limiting doses of DNP‐lys‐S3 preferentially suppressed antibody‐secreting cell levels, and had less effect on RFC. DNP‐lys2.5−S3 was 500—1000‐fold more potent in “blockading” primary RFC in vitro than DNP‐lys0.6−S3, whereas both antigens were equally effective in blocking secondary RFC.These results suggest that the sensitivity of primed B lymphocytes to inactivation by DNP‐lys‐S3 is related to their high avidity for antigen. Furthermore, this appears to be largely due to a high density of immunoglobulin receptors on primed cells, since the affinitiesof primary and secondary RFC for monovalent hapten were indistinguishable.Treatment of primarily immunized mice with DNP‐lys2.5−S3 2 h before assay abolished 90 % of RFC. Therefore, the reduction in RFC levels in tolerant mice may be due to cellular blockade by persisting tolerogen. However, it seems unlikely that simple blockade of antigen‐reactive cells is the sole mechanism operative in this system.
Hapten‐induced B cell paralysis. II. Evidence for trivial mechanisms of tolerance
Authors: Gronowicz E , Coutinho A 
Published: February 2007

AbstractInjection into mice of a free, reactive form of the hapten (4‐hydroxy‐3,5‐dinitrophenyl)acetyl (NNP), induces a state of specific unresponsiveness to the hapten, upon its challenge with thymus‐dependent and independent carriers. This unresponsiveness is maintained in vitro. Both induction and expression of the unresponsive state were found to be independent of T cells.Analysis of the mechanisms responsible for the B cell “tolerance” demonstrated that the major cause of unresponsiveness in this system is the blockade of specific surface receptors on B cells by the hapten, abolishing the focusing function of these receptors. “Tolerant” B cells, though they were unresponsive to the antigen, could be activated to anti‐hapten antibody secretion by the B cell mitogen lipopolysaccharide (LPS), which does not require Ig‐mediated binding. They also became fully responsive to the antigen NNP‐LPSin specific thymus‐independent responses after 24 hours of in vitro incubation in the absence of tolerogen, conditions which allowdeblocking of Ig surface receptors, and, thus, restorationof the focusing function of these receptors.These results demonstrate that great care is required for a clearcutdefinition of B cell tolerance. In this example, the tolerant B cells were perfectly responsive to a competent ligand, and no indication of an altered triggering or effector processes was found. It appears that in this, as in many other cases of B cell tolerance, the systems or the animals are tolerant, whereas B cells maintain a resting nonactivated state and are fully responsive to the triggering signal. Thus, the existance oftolerance‐inducing signals resulting in B cell unresponsiveness isquestioned.
Induction of allergic encephalomyelitis using hydrosoluble mycobacterial fractions
Authors: Westall F. C. , Thompson Millie , Migliore‐Samour Daniele , Jollès P. 
Published: February 2007

AbstractExperimental allergic encephalomyelitis has been induced in guinea pigs employing bovine myelin basic protein as the antigen and a hydrosoluble tetrasaccharide‐heptapeptide from delipidated cells of the human mycobacterial strain H37Ra as adjuvant. The maximum response was observed using 33 μg of antigen and 12.5 μg of adjuvant per animal.
The genetic control of T cell‐mediated immunity against the DBA/2 mastocytoma P‐815. II. Low responsiveness in T cell‐mediated cytotoxicity accompanied by the inability to produce antibodies in a secondary response
Authors: Kölsch E. 
Published: February 2007

AbstractLow responsiveness of DBA/1 mice in T cell‐mediated cytotoxicity against the DBA/2 mastocytoma P‐815 (H‐2d) is genetically controlled and inherited as a recessive trait. For an analysis of the humoral anti‐H‐2d response of DBA/1 mice after immunization with P‐815 mastocytoma cells both complementdependent lysis (CDL) and the cytotoxicity inhibition assay (CIA) were used to demonstrate antibodies. Both assays show that DBA/1 mice are unable to produce anti‐H‐2d antibodies in a secondary response. Even high doses of immunizing cells give only a weak response. is fully recovered upon allogeneic interaction. A transient primary anti‐H‐2d activity can be found in the CIA but not by CDL.The data show that the genetically controlled determinant‐specific defect in T cell‐mediated cytotoxicity among DBA/1 mice has its correlate in a blockade of memory formation or expression in the humoral anti‐H‐2d response.
Spontaneous release of T cell receptors for alloantigens. III. The effects of anti‐T cell receptor antiserum, of alloantiserum and of trypsin on T cell receptor release
Authors: Ramseier H. 
Published: February 2007

AbstractSpleen and lymph node T lymphocytes cultivated in vitro spontaneously released receptors for alloantigens. Among the various specificities, those receptors fitting certain alloantigens could be absorbed by formolized cells or proper genotype without influencing receptors for other alloantigensShedding of T cell receptors could be inhibited for 8 h by treating cells with antisera directed against T cell receptors (anti‐RS antisera). Inhibition experiments indicated that resynthesis of T cell receptors appears to be complete by 8 h. Experiments on prevention of receptor shedding revealed highly specific and presumably cytotoxic elimination of T cells with receptors for given alloantigens.Treatment of cells with alloantiserum obtained by skin graft rejection failed to inhibit spontaneous release of T cell receptors, whereas treatment of lymphocytes with trypsin resulted in an 8‐h delay of receptor shedding similar to that after treatment of cells with anti‐RS antisera. This inhibition was, however, nonspecific.
Derangements of immunoglobulin levels, phytohemagglutinin responsiveness and T and B cell markers in Down's syndrome at different ages
Authors: Burgio G. R. , Ugazio A. G. , Nespoli L. , Marcioni A. F. , Bottelli A. M. , Pasquali F. 
Published: February 2007

AbstractImmunologic studies were performed in 83 patients with Down's Syndrome (DS) in ages ranging from a few months to 30 years and 76 karyotypically normal age‐matched controls. The results show that both thymus‐dependent and independent functions were impaired in DS with a characteristic age sequence.Serum immunoglobulin levels were normal in children with DS less then 5 years old; after 6 years of age a definite hyperglobulinemia of the IgG and IgA type was observed. A slight decrease in IgM was observed between 16 and 25 years of age.In subjects with DS lymphocyte phytohemagglutinin responsiveness was in the normal range during the first decade but it decreased thereafter progressively; the percentage and absolute number of peripheral blood lymphocytes forming “spontaneous rosettes” with sheep erythrocytes were abnormally low at all ages including infancy; the number of circulating lymphocytes with a high density of surface immunoglobulins was always in the normal range.
Formation of plaques by adherent spleen cells from nonimmunized mice, incubated in vitro with the nonadherent fraction of immune allogeneic cells
Authors: Löwy Ilana , Bussard A. E. 
Published: February 2007

AbstractTwenty‐four‐hour incubation of adherent spleen cells from normal C57BL mice with purified nonadherent spleen cells from CBA mice, in the peak of their primary response against sheep red blood cells, resulted in the appearance of plaque‐forming cells in the adherent cell population. The immunological nature of these plaques was demonstrated by their complement dependency and the inhibitory effect of specific anti‐mouse IgM serum. Direct, but not indirect plaque formation was found to be associated with the adherent cell population for which direct cell to cell contact is necessary. Experiments with cytotoxic specific anti‐strain sera revealed that in this system, the adherent plaque‐forming cells are the nonimmune adherent C57BL cells.
Effect of alloantisera on the immune response of rat spleen cells against sheep red blood cells in vitro
Authors: Bhakdi‐Lehnen Birgit , Günther E. 
Published: February 2007

AbstractAlloantisera directed against antigens determined by the major histocompatibility system or by the genetic background of the rate are able to completely inhibit the primary IgM immune response of rat spleen cells against sheep red blood cells in vitro. Full inhibition is elicited only when the alloantisera are added during the first 48 hours of cultivation. Alloantisera that inhibit a primary immune response do not inhibit a secondary IgM response to sheep red blood cells in vitro by spleen cells primed 10–28 days before.
A theory of regulation and self‐nonself discrimination in an immune network
Authors: Hoffmann G. W. 
Published: February 2007

AbstractA mechanism is suggested for the regulation of the immune response that involves antigen‐binding and anti‐idiotypic lymphocytes. The cross‐linking of receptors is postulated to be a general mechanism for triggering T cells, B cells and cytotoxic effector cells (e.g. macrophages). A key role in regulation is ascribed to antigen‐specific T cell‐dependent factors, which are assumed to be able to block the receptors of both T cells and cells of the anti‐idiotypic specificities.The simple postulates of the model lead to feasible mechanisms for the helper, suppressor and killer roles of T cells, cellular and humoral immune responses, low zone tolerance and the tolerogenic effects of monomers, immune memory, antigenic competition, the abrogation of tolerance with cross‐reacting antigens, the usefulness of the switch from IgM to IgG, and self‐tolerance to both serum antigens and cell surface antigens. Biological roles are suggested for one of the Ia antigens and β2‐microglobulin. The theory leads to a number of predictions, which can be tested experimentally.A simple mathematical model is included, which provides an indication of how the theory may be further developed on a quantitative basis.
Induction of T and B cell immunity by anti‐idiotypic antibody
Authors: Eichmann K. , Rajewsky K. 
Published: February 2007

AbstractA small dose of the IgG1 fraction of anti‐idiotypic antibody (āId 1) raised in guinea pigs against a strain A/J antibody specific for streptococcal Group A carbohydrate sensitizes A/J mice against Group A streptococci. This is opposed to the previously established suppressive function of anti‐idiotypic antibody of the IgG2 class (āId 2). Correspondingly, āId 1 but not āId 2 is eliminated from the circulation in the way typical of an immunogenic molecule. However, the stimulatory component in the IgG1 fraction is not necessarily itself IgG1 antibody.Sensitization occurs in both B and helper T lymphocytes and is specific for Group A streptococci. In the B cell compartment sensitization is restricted to precursor cells expressing the idiotype. The concomitant activation of T helper cells therefore suggests that these cells make use of receptors with a similar or identical idiotype.Efficient sensitization by āId 1 of both T and B cells is also demonstrated in strain C57L/J mice which upon immunization with Group A streptococci express a partially cross‐reacting idiotype as a minor component. When such animals were primed with āId 1, essentially all of the anti‐carbohydrate antibody carried the partially cross‐reacting idiotype.
Cross‐reactivity patterns of IgM and IgG anti‐lipopolysaccharide antibodies in individual mice
Authors: Di Pauli R. 
Published: February 2007

AbstractA sensitive method has been developed which permits comparative analysis of IgM and IgG antibody specificity against lipopolysaccharide (LPS) antigen. It is based on hemolysis of LPS‐coated red blood cells and on its inhibition by homologous and heterologous LPS. By appropriate use of anti‐immunoglobulin sera, indirect (facilitated) lysis due to IgG antibodies is obtained, whereas IgM gives direct lysis and is 2‐mercaptoethanol‐sensitive. IgG can be analyzed either by facilitation with a rabbit anti‐mouse Ig or with anti‐allotype sera. By use of anti‐allotype sera in F1 hybrids, both parental antibody types can be studied separately.Antibodies of either class from individual mice may display different cross‐reactivity patterns. Furthermore, for IgM and IgG within a given serum, both similarities and differences have been found. Some of the cross‐reactivity patterns have been followed over one year. With few exceptions, individual patterns remained constant throughout this period.