bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractImmunofluorescent 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

AbstractWhen 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

AbstractWhen 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

AbstractSurface 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

AbstractGraft 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

AbstractA 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

AbstractWe 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

AbstractThis 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

AbstractMice 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

AbstractThe 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

AbstractResistance 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

AbstractSpleen 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

AbstractIncubation 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

AbstractA 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

AbstractPreformed 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

AbstractSeparation 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

AbstractThe 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

AbstractAllelic 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.