bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bursa lymphocytes and IgM‐containing cells in chicken embryos bursectomized at 52–64 hours of incubation
Authors: Janković B. D. , Knežević Z. , Isaković Katarina , Mitrović Kosana , Marković B. M. , Rajčević Miroslava 
Published: February 2007

AbstractA technique of surgical removal of the bursal primordium (“bursectomy”) of chicken embryos at stage 17, approximately 52–64 hours and 29–32 somites, is described. The survival rate of bursectomized (Bx) embryos approached a level of 50% on the 21 st day. About 20% of correctly Bx embryos exhibited malformations of the anal sphincter and the large intestine. Using a rabbit anti‐bursacyte serum, which did not react with thymocytes, the specific bursa‐derived cell (Bu) marker was detected on the surface of bursa, spleen, bone marrow and thymus lymphocytes. Early embryonic bursectomy caused a moderate depletion of Bu marker‐bearing and IgM‐containing cells. It has been postulated that embryonic Bu cells can be recruited from sites other than the bursa and in the absence of the bursa.
The analysis of the monoclonal immune response to influenza virus. I. Production of monoclonal anti‐viral antibodiesin vitro
Authors: Gerhard W. , Braciale T. J. , Klinman N. R. 
Published: February 2007

AbstractLimiting numbers of spleen cells from mice primed with influenza virus were transferred into lethally irradiated syngeneic recipients. Upon antigenic stimulation of fragment cultures of the recipient spleens it was observed that a linear relationship existed between the number of transferred spleen cells and the number of responding fragments. The antibody product of individual fragments exhibited a highly restricted heterogeneity in isoelectric focusing as well as in its reactivity against various viral antigenic determinants. It was concluded that the limiting cell type in this adoptive transfer system corresponds to the virus‐primed B cell which, upon antigenic stimulation, gives rise to a clone of antibody‐producing cells. PR8‐specific precursor B cells occurred at a frequency of at least 1/4000 splenic B cells in PR8‐primed BALB/c mice. Approximately 25% of the stimulated cell clones produced sufficient quantities of antibody (200 ng) to render feasible an analysis of closely related viral antigens.
A leukocyte migration inhibition assay technique using blood clot fragmentsin vitro
Authors: Sandru G. 
Published: February 2007

AbstractConcomitantly with the capillary tube method, anin vitroleukocyte migration inhibition assay technique using blood clot fragments was performed in chicken egg albumin, Bacillus Calmette Guérin and complete Freund's adjuvant‐treated immune guinea pigs. Results of both methods were concordant.
Neonatally induced transplantation tolerance: in vitro evidence supporting a clonal inactivation mechanism
Authors: Brooks C. G. 
Published: February 2007

AbstractMixed lymphocyte culture (MLC) tests on the cells of mice made fully tolerant to allogeneic tissues in neonatal life showed an absence of specific antigenreactive cells. Similarly, no cells cytotoxic in a chromium release test could be detected. The absence of reactivity in the tolerant populations could not be accounted for by either suppressor cell activity or serum blocking factors. By contrast, mice in which partial tolerance had been deliberately or inadvertently induced often possessed detectable numbers of MLC‐reactive cells and, after grafting, their sera inhibited the MLC reactivity of normal cells. These results are discussed in terms of possible mechanisms of self tolerance.
The specific blocking of humoral immune cytolysis mediated by anti‐tumor antibodies degraded by lysosomal enzymes of tumor origin
Authors: Keisari Yona , Witz I. P. 
Published: February 2007

AbstractThe IgG fraction from rabbit antisera against a mouse plasmacytoma (RaPCT‐IgG) was incubated, under acidic conditions, with lysosomal extracts (LE) derived from the corresponding tumors. The LE‐treated IgG demonstrated a significant decrease in its complement‐dependent cytotoxic potential when compared to RaPCT‐IgG incubated without LE under the same conditions (control IgG).Ammonium sulfate (AS) precipitation of the control IgG and the LE‐treated IgG preparations at 40% saturation of AS revealed that some of the IgG lost its precipitability at this AS concentration after LE treatment, but could be precipitated at 60% or 70% saturation. The LE‐treated IgG and control IgG fractions that precipitated by 40% saturated AS showed similar gel filtration profiles. The LE‐treated IgG fraction precipitating at 70% saturation of AS (but not at 40%) showed a different gel filtration profile. This fraction was separated into several subfractions, some with an apparent lower molecular weight. Some of these subfractions which still contained antigenic IgG lacked any expression of antigenic Fc, and were not cytotoxic to tumor cells. They could, however, rebind to tumor cells and block the complement‐dependent cytotoxic activity of native RaPCT‐IgG.Lysosomal enzymes of tumor origin seem, therefore, to convert cytotoxic antitumor antibodies into molecules devoid of Fc but still retaining their antigen binding activity. Such an activity, if occurring in vivo might enhance tumor growth.
Effector‐cell blockade. II. A demonstration of the reversible masking of an immune response by blockade of antibody‐forming cells
Authors: Schrader J. W. 
Published: February 2007

AbstractPreviously we showed that multivalent forms of antigen could specifically block the effective secretion of antibody by binding to the antibody‐forming cell (AFC). We termed this inhibition of antibody‐secretion at the level of the AFC “effector cell blockade” (ECB). The present paper shows that dinitrophenylated gelatin, (DNP‐GEL), can induce ECB in vitro. Thus, portions of a suspension of spleen cells from DNP‐immune mice were incubated for 30 min with DNP‐GEL, washed and then assayed for anti‐DNP‐plaque‐forming cells. The resultant plaques were much fewer and smaller than those in assays of control portions of the spleen cell suspension. This DNP‐GEL‐induced ECB was shown to be reversible by treatment of the DNP‐GEL‐incubated cells with the specific enzyme collagenase. The reversibility of ECB by removal of extracellular antigen was confirmed using the multivalent antigen DNP‐glucan, together with the enzyme β‐lichenase, an enzyme with no action on mammalian carbohydrates.The in vitro response to dinitrophenylated polymerized flagellin could be inhibited by the addition of DNP‐GEL at any time during the culture period. However, after the early hours of culture, the inhibition caused by the addition of DNP‐GEL was totally reversible by treatment of the cells with collagenase after harvest and immediately prior to assay. This demonstrated that B cells could divide and differentiate to AFC, despite the presence of multivalent forms of specific antigen in concentrations sufficient to block, by ECB, the detection of a response using a hemolytic plaque method.The demonstration that persistent, multivalent antigen can produce a state of apparent unresponsiveness in spite of the presence of an ongoing immune‐response suggests that the importance of a reversible masking of an immune response by ECB should be evaluated in all models of tolerance using this class of antigen.
Effect of polyamines on the proliferative response of T cells stimulated with antigen
Authors: Ballet J. J. , Preisig E. , Merler E. 
Published: February 2007

AbstractPresence of polyamines in cultures of human lymphocytes amplifies the proliferative response of sensitized T cells to antigens in vitro. Similar effects of aminoguanidine, an inhibitor of diamine oxydase, suggests a role of endogenous polyamines in normal proliferative events. This effect may have practical application in the amplification of low in vitro responses to antigens and in mixed lymphocyte cultures.
Polygenic regulation of antibody synthesis to sheep erythrocytes in the mouse: a genetic analysis
Authors: Feingold Nicole , Feingold J. , Mouton Denise , Bouthillier Yolande , Stiffel Claude , Biozzi G. 
Published: February 2007

AbstractSelective breeding for the character “agglutinin production to heterologous erythrocytes” was performed on random‐bred populations of albino mice. Two types of selection were carried out: Selection I: the first 6 generations were immunized with sheep erythrocytes (SE), then SE and pigeon erythrocytes (PE) were alternated at each generation to avoid the interference of maternal antibody. Selection II: all generations were immunized with SE 60–70 days after weaning in order to eliminate the maternal antibody. Both were selected for the character agglutinin titer 14 days after immunization using an optimal dose of erythrocytes.Selection I. The mean response to SE of the foundation population was 7.36 ± 1.60. The selection limit was attained between the 15th and the 20th generation. The F20−F30were considered as homozygous for the character investigated. The mean SE agglutinin titers were 9.15 (1/2820) in the high responder line and 2 (1/20) in the low responder line. This corresponds to 140‐fold interline difference in agglutinin titers. SE agglutinins determined in F1 hybrids, F2 hybrids and backcrosses obtained from F23 − F29 demonstrated incomplete dominance of high responsiveness (23–29%).The inbreeding coefficient produced by close colony breeding was 0.55 in high and 0.71 in low responders at the 20th generation when both lines were homozygous with respect to agglutinin synthesis.Selection II. The mean response of the foundation population to SE was 7.79 ± 1.56. The selection limit was attained in F14−F17 generations that were considered homozygous for the character investigated. The mean SE agglutinin titer was 9.2 (1/2900) in high responders and 2.8 (1/35) in low responders, which is an 83‐fold interline difference in agglutinin titers. The results of both selections indicate that the character agglutinin synthesis is subject to polygenic regulation. The heritability (h2) of this character was estimated to be between 0.18 and 0.36 (range between the extreme values of Selections I and II).The attempt to evaluate approximately the number of “loci” is compatible with the hypothesis that a group of about 10 loci regulates the quantitative antibody response. The sources of errors of this evaluation and the significance of the term “loci” are discussed.
Reversible binding of a T cell factor on IgG‐coated Sepharose beads
Authors: Guimezanes A. , Fridman W. H. , Gisler R. H. , Kourilsky F. M. 
Published: February 2007

AbstractSupernatants of alloantigen‐activated T cells contain a number of factors, including an immunoglobulin‐binding factor (IBF) which inhibits complement‐induced hemolysis of sheep erythrocytes coated with anti‐Forssman IgG anti‐bodies and a factor which suppresses IgM antibody synthesis in vitro. These two factors may be identical, since they are simultaneously retained on Sepharose beads to which IgG has been coupled and can be recovered by elution at pH 2.8. They do not bind to Sepharose beads to which IgM of F(ab′)2 fragment of IgG has been coupled, demonstrating that they have a selective affinity for the Fc region of IgG. In addition, the fixation of IBF on the Fc portion of IgG reversibly inhibits subsequent binding of the first component of complement (C1), thus indicating that IBF does not irreversibly alter the C1 binding site(s) of IgG.
HLA antigens: rabbit antisera reacting with all A series or all B series specificities
Authors: Cresswell P. , Ayres Janet L. 
Published: February 2007

AbstractPapain‐solubilized HLA antigens giving only two bands of 34 000 mol.wt. and 11 000 mol.wt. by sodium dodecyl sulfate (SDS) gel electrophoresis and isolated from the cultured human lymphoblastoid cell line RPMI 4265, have been used to prepare antisera in rabbits. Antisera were raised against soluble products of the A (or 1st) series of HLA, bearing the determinant HLA‐A2 (A2 substance), or against a mixture of products of the B (or 2nd) series of HLA, bearing the determinants HLA‐B7 and HLA‐B 12 (B7‐12 substances). Rabbit antisera to A2 substance reacted primarily with A2 substance on Ouchterlony analysis, showing an apparent spur of cross‐reactivity with B7‐12 substances. Rabbit antisera to B7‐12 substances reacted primarily with B7‐12 substances, giving a spur of cross‐reactivity with the A2 material. Neither antiserum precipitated β‐2microglobulin. Both types of sera reacted with membrane molecules of 43 000 mol.wt. and 11 000 mol.wt. by immune precipitation and gel electrophoresis in SDS of detergent‐solubilized radiolabeled membranes from cultured cell lines, as predicted for sera directed towards HLA antigens. F(ab′)2 fragments of the antibodies blocked the complement‐mediated cytotoxicity of all HLA alloantisera tested for human peripheral blood lymphocytes. After absorption with B7‐12 substances, F(ab′)2 fragments of antisera to A2 substance only blocked the cytotoxicity of HLA alloantisera to A series specificities. After absorption with A2 substance, F(ab′)2 fragments of rabbit antisera to B7‐12 substances only blocked the cytotoxicity of HLA alloantisera to B series specificities. The results prove the existence of shared antigenic determinants between all members of the same series. These findings support the genetic evidence that A series HLA antigens are allelic products of a single locus, while B series HLA antigens are allelic products of a separate locus, by establishing some invariance of structure, presumably amino acid sequence, between members of the same series. The apparent cross‐reactivity between A2 substance and B7‐12 substances, and the ability of the unabsorbed F(ab′)2, preparations to block the cytotoxicity of all HLA alloantisera, suggests that some determinants are common to both HLA loci. This may be considered to support the hypothesis that the two loci arose by gene duplication.
Structural and immunological similarities between HLA antigens from three loci
Authors: Rask L. , Lindblom J. B. , Peterson P. A. 
Published: February 2007

AbstractHLA antigens are coded for by three closely linked loci. The gene products of the first and second locus are known to be very similar in overall structure. Antigens coded for by the third locus were examined with regard to their chemical and immunological relationship to the first and second loci gene products. It is demonstrated that the third locus antigens are composed of two types of polypeptide chains, the smaller of which is identical to β2‐microglobulin. The alloantigenic polypeptide chain has an apparent molecular weight of 48 000 when solubilized by detergent treatment and about 35 000 when released from the cell membrane by proteolysis. These data together with size and shape analyses by gel chromatography and sedimentation velocity determinations show that HLA antigens from the three subloci are indistinguishable with the techniques employed. Suggestive evidence was obtained that the third locus antigens are more sensitive to proteolysis than the first and second locus antigens.The similarity between the three gene products was also evident on cyanogen bromide fragmentation of the polypeptide chains. Furthermore, rabbit antibodies against antigens coded for by the first locus cross‐reacted extensively with antigens from the second and third locus. This study therefore lends strong credence to the view that the three HLA antigen subloci have arisen by gene duplications of a common ancestral gene.
Detection of anti‐idiotype reactive cells in the response to phosphorylcholine
Authors: Cosenza H. 
Published: February 2007

AbstractUpon immunization with phosphorylcholine (PC), BALB/c mice produce antibodies bearing mainly one idiotype which is identical to that of the TEPC 15 PC‐binding myeloma protein. By coating sheep red cells (SRC) with TEPC 15 it was possible to detect anti‐idiotypic plaques during the course of an immune response to PC. These plaques are detectable only after the anti‐PC response has reached a peak and begun to decline. They are specific, since addition of free TEPC 15 and not MOPC 315 prevented their detection. It is suggested that such anti‐idiotypic reactive cells might regulate the response to PC.
Studies on the lymphocytes of sheep. I. Recirculation of lymphocytes through peripheral lymph nodes and tissues
Authors: Hall J. , Scollay R. , Smith Marilyn 
Published: February 2007

AbstractRecirculating lymphocytes were collected from the efferent ducts of peripheral somatic nodes and incubated in vitro with 51Cr. After washing, the labeled cells were returned to the sheep by i.v. injection. The partitioning of the labeled cells between blood and efferent (intermediate) lymph, or between efferent and afferent (peripheral) lymph was monitored for the next 24 h by assaying the radioactivity in appropriate samples of cells.The labeled lymphocytes took several hours to migrate through the nodes so that they equilibrated between blood and lymph in about 10 h. This pattern was not altered grossly during the inductive phase of an immune response.The small numbers of lymphocytes which migrated through peripheral tissues entered the lymph at least as quickly as those that migrated through lymph nodes.
Correlation of PPD and BCG‐induced leukocyte migration inhibition, delayed cutaneous hypersensitivity, lymphocyte transformation in vitro and humoral antibodies to PPD in man
Authors: Fleer A. , van der Hart Mia , Blok‐Shut B. J. Th. , Schellekens P. Th. A. 
Published: February 2007

AbstractIn a study of healthy human individuals a complete lack of correlation between the results of the agarose leukocyte migration inhibition (LMI) test, using purified protein derivative (of tuberculin) (PPD) and Bacillus Calmette Guérin (BCG) as antigens, and delayed cutaneous hypersensitivity and lymphocyte transformation in vitro to PPD was found. There was a reasonable correlation between PPD‐ and BCG‐induced LMI.Antibodies to PPD proved to have no influence on PPD‐induced LMI. Purified polymorphonuclear leukocytes, whether derived from donors sensitive to PPD in the agarose LMI test or from nonsensitive donors, did not show migration inhibition to PPD.It was concluded that polymorphonuclear leukocytes and lymphocytes need to be present simultaneously for migration inhibition of peripheral blood leukocytes by PPD.Furthermore, because a consistent relation with conventional parameters of cell‐mediated immunity was lacking, it is doubtful whether the agarose LM1 test can be considered as an alternative parameter of this kind of immunity.
B cell tolerance induced by polymeric antigens IV. Antigen‐mediated inhibition of antibody‐forming cells
Authors: Klaus G. G. B. 
Published: February 2007

AbstractThe role of antibody‐forming cell (AFC) blockade in the genesis of hapten‐specific tolerance induced by hapten (2,4‐dinitrophenyl)‐coupled pneumococcal polysaccharide (DNP‐lys‐S3) was investigated. Tolerizing doses of DNP‐lys‐S3 given to mice making antibodies to DNP‐hemocyanin a day before assay markedly reduced numbers of detectable anti‐DNP AFC. Furthermore, anti‐DNP AFC were specifically inhibited by brief in vitro incubation with DNP‐lys‐S3, followed by extensive washing. This inhibition requires multivalent binding of tolerogen to immunoglobulin receptors on AFC, and appears to result from a decrease in the rate of antibody secretion per cell.A variety of data indicate that IgM AFC are more susceptible to blockade than IgG AFC, and the susceptibility of both cell types decreases with time after immunization. This probably reflects differences in the density and in the rate of loss of surface immunoglobulin receptors on IgM and IgG AFC and their immediate precursors.However, we conclude that under “conventional” tolerizing conditions, i.e. when tolerogen is given prior to immunogen, DNP‐lys‐S3 suppresses antibody formation primarily by inactivating DNP‐specific precursor cells. AFC blockade is therefore probably only relevant in the suppression of (primary?) IgM responses by large doses of tolerogen. The relative importance of precursor inactivation and AFC blockade in tolerogenesis of IgM responses to T cell‐independent antigens (such as 53) remains to be elucidated.
N‐terminal amino acid sequence of a human delta‐chain myeloma protein
Authors: Milstein Celia P. , Northrop F. 
Published: February 2007

AbstractThe N‐terminal amino acid sequence (26 residues) of a δ‐chain of a human myeloma (Er I) is homologous with the prototype sequence of the human VHIII subgroup. This indicates that the δ‐chain is using for its V region the same pool of V genes as the rest of the immunoglobulin classes. Implications of this finding are discussed.
Enzymatic removal of H‐2 alloantigens from the surface of P815‐(X2) mouse tumor cells
Authors: Thomas K. , Engers H. D. , Cerottini J.‐C. , Brunner K. T. 
Published: February 2007

AbstractAfter treatment with papain (6 mg/ml) for 1 h, P815 tumor cells became resistant to complement‐mediated lysis by mouse alloantibodies of different specificities. Immunofluorescence and absorption studies indicated that this resistance was associated with removel of the corresponding antigenic determinants from the cell surface. In contrast, papain‐treated tumor cells were fully susceptible to lysis by rabbit antiserum against P815 cells, indicating a) no alteration of the membrane sensitivity to complement damage, and b) a dissociation between structure and/or localization of allo‐ and xenoantigens.Papain‐treated cells were also completely resistant to lysis by cytolytic T lymphocytes (CTL) during the first 60 min after completion of the enzyme treatment. Susceptibility to lysis by either CTL or alloantibody and complement reappeared within a few hours after incubation in culture medium and was virtually normal by 6 h. Treatment of P815 cells with trypsin (2 mg/ml) had no effect on either humoral or cellular lytic activities.
Study of A100 allotypic specificity of rabbit immunoglobulins The cross‐reactivity between A100, a1 and a3
Authors: Cazenae P.‐A. , Bréezin Colete 
Published: February 2007

AbstractEvidence for the genetic determination of A100 allotypic specificity suggests that it is the product of an allele at the a locus. The A100 allotypic specificity was detected in a wild rabbit lacking all the known specificities of the a series. None of the 8 rabbits possessing the A100 allotypic specificity possessed two allotypic specificities of the a series. The concentration of A100+ molecules is larger in the serum of a presumably homozygous rabbit than in that of a presumably heterozygous rabbit. In the sera of heterozygous A100+ rabbits, the A100 allotypic specificity and the known specificity of the a series are carried by different molecules. The determinants responsible for the A100 allotypic specificity are present both on IgG and IgM. They are located on the heavy chain and the Fab fragment of IgG. A family of variants of A100 specificity has been detected and cross‐reactivity between A100, a1 and a3 specificities has been found. This was detected and studied with anti‐a3 antisera. It seems that A100 allotypic specificity is closer to a3 specificity than a1 is to a3 specificity.