bluuebunny/crossref_metadata_2025_split huggingface dataset:
IgG2 and other immunoglobulin classes on the cell surface of rat lymphoid cells
Authors: Williams A. F. 
Published: February 2007

AbstractThe binding to rat lymphoid cells of the F(ab′)2 fragments of purified rabbit antibodies specific for the Fc or Fd part of rat IgG2 was studied. Both reagents heavily labeled about 15 % and 6 % of cells from spleen and cervical lymph nodes respectively of rats kept in a conventional animal house. In contrast to this there were very few IgG2 positive cells in the thoracic duct lymph of any animals, or in the spleen of rats from an SPF animal house.Results on the quantitative binding of rabbit antibodies against rat Fab, IgM and IgA to rat lymphoid cells are also reported. IgM positive cells in the spleen bound much more anti‐IgM relative to their binding of anti‐Fab antibody, than IgM positive cells from thoracic duct lymph or cervical lymph node.
Relationship between the enhanced expression of histocompatibility antigens on interferon‐treated L 1210 cells and their position in the cell cycle
Authors: Killander D. , Lindahl Pernilla , Lundin Lena , Leary Patricia , Gresser I. 
Published: February 2007

AbstractWe have determined the cell cycle position of individual mouse leukemia L 1210 cells by cytophotometric and autoradiographic techniques and simultaneously determined the amount of histocompatibility antigens expressed on the surface of individual cells by quantitative immunofluorescence. Interferon treatment of L 1210 cells was accompanied by an enhanced expression of histocompatibility surface antigens. The distribution of interferon‐treated cells in the various phases of the cell cycle was similar to that for control cells and the enhanced expression of histocompatibility antigens was observed on interferon‐treated cells in all phases of the cell cycle. We conclude, therefore, that this enhancement is not due to a preferential concentration of these cells in any one particular phase of the cell cycle.
Ontogeny of adherent cells. I. Distribution and ontogeny of A cells participating in the response to sheep erythrocytes in vitro
Authors: Landahl Carol Ann 
Published: February 2007

AbstractAn adherent (A) cell function required for the in vitro antibody‐forming response to sheep erythrocyte (SRBC) antigen has been demonstrated in a culture medium enriched with nucleic acid precursors and 2‐mercapto‐ethanol. The essential function is fulfilled best by adult adherent cells of the spleen, to some extent by bone marrow and perhaps lymph node A cells, and poorly or not at all by peritoneal or lung A cells. Ontogenetic studies reveal the absence or inhibition of neonatal A cell synergistic function in the in vitro response to SRBC. The capacity of splenic adherent cells to collaborate with column‐separated nonadherent cells appears only from the third or fourth day after birth, with ratio indices reaching levels significantly greater than nonsynergistic background by the fifth day and showing little further increase until the second week of age.
Fc‐rosetting and nonrosetting T cells are killer cells
Authors: Krammer P. H. , Elliott B. E. , von Boehmer H. 
Published: February 2007

AbstractA fraction of T cells activated to H‐2 determinants in vivo (ATC) express Fc receptors (FcR) on the cell surface. Those FcR can be detected by antibody coated red blood cells (EA rosettes). Nonrosetting and EA rosetting ATC could be obtained in highly enriched form (more than 99 % pure) by separation by velocity sedimentation at unit gravity. Separately tested, both fractions of ATC showed killer cell activity against specific target cells. Possible explanations why only one population of T killer cells expressed FcR are discussed.
The effect of short‐term culture on the sensitivity of MDAY murine tumor cells to lysis mediated by normal rabbit serum
Authors: Caspi Rachel , Witz I. P. 
Published: February 2007

AbstractFreshly explanted MDAY murine tumor cells are sensitive to lysis mediated by fresh normal rabbit serum. The sensitivity, which increases with the age of the tumor, is rapidly lost upon short‐term culture, and takes place at 37 °C but not at 4 °C.Cellular components released into the medium during short‐term culture are capable of eliciting xenogeneic antibodies that mediate complement‐dependent lysis of such cells.
Isolation of antigen‐binding cells from unprimed mice. II. Evidence for monospecificity of antigen‐binding cells
Authors: Julius M. H. , Janeway C. A. , Herzenberg L. A. 
Published: February 2007

AbstractSpleen cells from unimmunized mice were exposed to two contrastingly fluorescent antigens simultaneously. Antigen‐binding cells of either specificity were isolated using a fluorescence‐activated cell sorter (FACS). Purified cells binding one or the other of the antigens were then examined by fluorescence microscopy for the presence of bound antigen of the alternate specificity.No double binding cells were seen. If cells bear receptors of two or more specificities and these receptors are randomly distributed among antigen‐binding cells, then of the 13 000 binding cells examined 82 were expected to bind both antigens. These results strongly suggest that antigen‐binding cells bear receptors of only one specificity. In addition, by inference from the functional correlation between antigen‐binding cells and precursor cells, the data support the contention that precursors of antibody‐forming cells are monospecific.
Detection of immunologically active zones in equine growth hormone
Authors: Poskus E. , Zakin M. M. , Fernández H. N. , Paladini A. C. 
Published: February 2007

AbstractPeptide fragments, obtained from equine growth hormone by cyanogen bromide cleavage and further chemical treatment, were isolated and identified. Their immunological reactivities were tested by hemagglutination and complement fixation methods using rabbit antisera against native hormone.Antigenic determinants were detected in the fragments comprising amino acid sequences 5–72 and 73–123, this last one being predominant. Fragment 124–178 had very low reactivity. Nitration of peptide 73–123 did not modify its immunological properties, but oxidation diminished them.Comparison of the antigenicity of equine growth hormone fragment 73–123 with that of the homologous ovine growth hormone fragment 86–123 lent support to the hypothesis that at least one antigenic determinant area in the horse hormone fragment is dependent on sequence 86–123.
Long‐term immunoglobulin G production by transplanted thymus cells
Authors: Micklem H. S. , Anderson N. , Ure Janice , Jones Helen Parry 
Published: February 2007

AbstractTwo sublines of CBA/H mice congenic for the Igl allotype locus were used to study donor‐allotype IgG2a concentrations in the serum of mice injected intravenously with thymus cells. High concentrations (up to several mg/ml) were found in x‐irradiated recipients(exposed to 650 rad, or to 900 rad with a restorative injection of fetal liver cells). The highest concentrations were seen 1–2 months after injection, but detectable quantities were still present in most individuals after 377 days. No donor‐allotype Ig was detected in non‐irradiated recipients. Cell for cell, lymph node cells were about as efficient as thymus cells at transferring IgG production. Although pluripotent hema‐ topoietic stem cells were found in the thymus, their concentration (about 10−8) was too low to account for the results. It is suggested that the thymus contains B lymphocytes, or their precursors, with considerably greater powers of self‐maintenance and expansion than are possessed, on average, by the B lymphocytes in lymph nodes.
Suppression of local graft‐versus‐host reactions by mouse fetal and newborn spleen cells
Authors: Skowron‐Cendrzak Anna , Ptak W. 
Published: February 2007

AbstractFetal splenic but not thymic lymphocytes significantly reduce the ability of parental adult spleen cells to elicit local graft‐versus‐host reactions in F1 recipients. This suppressive activity wanes early after birth. There is no requirement for histocompatibility between reacting and suppressor cells.
Reduction of trapping of aggregated human IgG in germinal centers by mitogens
Authors: Papamichail M. , Gutierrez Carmen , Embling P. , Holborow E. J. 
Published: February 2007

AbstractThe effect of nonspecific mitogens on the trapping of 125I‐labeled aggregated human IgG (125I‐AHGG) in germinal centers (GC) of mouse spleens has been investigated by both radioactivity uptake and immunofluorescence. Phytohemagglutinin and concanavalin A (Con A) significantly decreased trapping. Lipopolysaccharide produced less inhibition, and pokeweed mitogen had no significant effect. The maximum inhibition occurred with 250–500 μg Con A. This had no effect on 125I‐AHGG uptake in liver, kidney and blood. No differences were found between i.p. and i.v. routes of Con A injection.The effect of mitogens on the 125I‐AHGG trapping in GC is due more likely to modification of the migratory properties of lymphocytes brought about by surface binding, than to their mitogenic properties, since Con A decreased 125I‐AHGG localization in thymectomized, x‐irradiated and bone marrow‐ reconstituted animals.
Lack of neonatal susceptibility to induction of tolerance by polysaccharide antigens
Authors: Howard J. G. , Hale Christine 
Published: February 2007

AbstractSusceptibility to tolerance induction by polysaccharides during the neonatal period has been studied with the α‐1.3 and α‐1.6 glucosyl epitopes of dextran B 1355 in BALB/c mice and the β‐2.6 fructosyl epitope of levan in CBA mice.Acquisition of responsiveness, as measured by plaque‐forming cell (PFC) assays, is relatively late – taking more than 14 days to appear and 2–3 months to attain maturity in the case of α‐1.6 glucosyl and β‐2.6 fructosyl. The mice responded well to sheep red blood cells and 2,4‐dinitrophenylated (DNP) keyhole limpet hemocyanin (KLH) by 14 days, but were refractory to another thymus‐independent antigen DNP‐Ficoll. Nonresponsiveness of 2‐week‐old spleen cells to the polysaccharides was stable on transfer and could not be attributed to suppressor cells.Despite this long post‐natal phase of immaturity, no evidence was obtained of concomitant susceptibility to tolerance induction by dextran and levan. Response curves in mice injected at birth with weight‐adjusted doses revealed similar or even higher “high‐zone” thresholds to those tolerized at 3 months. Only partial α‐1.3 glucosyl tolerance is inducible in adults but this was no greater after neonatal exposure, which led also to short‐lived α‐1.6 tolerance. Repeated injections of B 1355 and levan during the first 10 days was no more tolerogenic, and PFC appeared spontaneously with maturity in mice given these antigens neonatally.Thus, the recognized neonatal susceptibility to thymus‐dependent antigens does not extend to these thymus‐independent antigens. It is therefore considered that tolerance studied with polysaccharides has little relevance to the mechanism of self‐tolerance acquired in the embryo and, in vivo, is determined by interaction with a relatively mature B cell rather than by “clonal abortion” of a tolerance‐sensitive precursor stage.
Production of xenogeneic and allogeneic antisera specific for mouse thymus‐derived lymphocytes
Authors: Bron C. , Anckers C. , Sauser D. 
Published: February 2007

AbstractXenogeneic and allogeneic antisera were raised in rabbits and mice using purified mouse T cell‐specific antigens. These antisera were shown to be reactive in complement and antibody‐dependent cell‐mediated cytotoxicity tests as well as in immunofluorescence, with 30 % of mouse spleen cells, 80 % of lymph node cells and 100 % of thymocytes or various T lymphoblastoid cell lines labeled.No reaction could be detected with bone marrow cells or non‐T cell lines. Both types of reagents bound to the same spleen lymphocyte subpopulations and competed for the same antigenic sites as anti‐Thy‐1.2 alloantiserum. These antisera raised with small amounts of immunogens did not require any absorption to be rendered specific for mouse T cells.
Identification of the murine leukemia viral antigens detected on mouse cells by H‐2 alloantisera
Authors: Milner R. J. , Henning R. , Edelman G. M. 
Published: February 2007

AbstractH‐2 alloantisera have been previously reported to contain antibodies against murine leukemia viral antigens, but the nature of the viral antigens on mouse cells which interact with these antibodies has not been established. We have found that H‐2 alloantisera recognize components of molecular weight 70 000 – 80 000 on mouse lymphocytes and leukemia cells. These components were also detected by a goat antiserum against the murine leukemia virus (MuLV) glycoprotein (gp70) and are therefore closely related to or identical with that viral protein.Although most H‐2 alloantisera detected gp70‐like molecules on lymphocytes and leukemia cells from a great variety of mouse strains, only one H‐2 alloantiserum was found to interact with a gp70 component on cells from C57BL/10 and C57BL/6 mice. Animals such as C57BL/10 mice that lacked the component reacting with most H‐2 alloantisera showed increased serum levels of anti‐MuLV antibodies after injection of B10.A spleen cells having a gp70 component detectable by other H‐2 alloantisera. In contrast, strains with cells reactive to antiviral antibodies in the H‐2 alloantisera had low responses to MuLV antigens after a similar immunization procedure. Serum levels of anti‐MuLV antibodies in both groups of mice, however, were increased after injection of Freund's adjuvant. These observations suggest that anti‐MuLV antibodies in mouse alloantisera may arise from a response to viral antigens on the immunizing cells and general stimulation of the immune system.
Uniformity in the clonal repertoire for the immune response to phosphorylcholine in mice
Authors: Claflin J. L. 
Published: February 2007

AbstractA comparison of the clonal nature of the immune response to phosphorylcholine (PC) was made in nine different inbred mouse strains. Quantitative idiotypic analysis showed that anti‐PC antibodies from each strain were composed of antibodies bearing binding‐site idiotypic determinants indistinguishable from two different BALB/c myeloma proteins, T15 and M511. Idiotypic determinants of two other PC‐binding proteins, M167 and M603, were not detected. Isoelectric focusing of the light (L) chains verified the presence of antibodies similar to T15 and M511 in each strain and indicated the presence of two additional antibodies, one of which has an L chain which cofocuses with M603. Fractionation of anti‐PC antibody with anti‐idiotypic antibody showed that immunoglobulins bearing T15 and M511 idiotypic determinants are separate and contain L chains that are uniform and resemble those of T15 and M511, respectively.Thus, these mice which differ genetically at multiple loci including the heavy chain allotype complex locus each possess, at least in part, an equivalent set of clonotypes specific for PC. This indicates that the genes encoding these antibodies must be contained in the germ line.
Effect of carrier‐specific tolerance on the generation of helper cell function
Authors: Sanfilippo F. , Cohn Marjorie L. , Scott D. W. 
Published: February 2007

AbstractThe effect of carrier‐specific tolerance on the development of helper cell function was studied in irradiated rats reconstituted with normal or carrier‐tolerant bone marrow. Bone marrow (BM) from normal rats or rats tolerant to sheep IgG (SGG) was transferred to lethally irradiated syngeneic recipients, which were challenged 3 to 5 weeks later when immunocompetence to T‐dependent antigens was shown to have recovered. When recipients were challenged with the 2,4,6‐trinitrophenyl (TNP) hapten coupled to SGG in adjuvant, groups which received SGG‐tolerant BM were 70–80 % unresponsive in terms of anti‐TNP plaque‐forming cells compared to recipients of normal BM. This effect was carrier (SGG)‐specific and was reversed when normal thymocytes were transferred with tolerant BM. Moreover, neither tolerant BM nor tolerant thymocytes were able to suppress the responsiveness of normal BM at a 1:1 ratio. These cell‐mixing experiments imply that the reduction in helper cell function is due neither to suppressor cells nor antigen carryover in the tolerant BM. It is suggested that a BM precursor of the helper T cell may be rendered tolerant and therefore already possesses antigen specificity prior to thymic migration.
Immune conservation: a possible consequence of the mechanism of interferon‐induced antibody suppression
Authors: Booth R. J. , Booth Joan M. , Marbrook J. 
Published: February 2007

AbstractThe effect of interferon preparations on the development of single clones of antibody‐forming cells generated against sheep red blood cells in mouse spleen cell cultures has been studied. It was found that the presence of interferon had no effect on either the number or the size of clones which developed early in the in vitro antibody response. At the peak of the response (day 3), a decrease in the number but not in the size of clones was observed in interferon‐treated compared to control cultures, while by day 4 both the size and number of clones were significantly decreased. These findings indicate that interferon appears to affect only nonactivated B cell precursors by preventing them from becoming activated and commencing clonal expansion. Early responding precursors, which are in cell cycle, presumably having been previously activated in vivo, are refractory to interferon‐induced suppression in vitro. The way in which this immunosuppressive activity of interferon might be of great advantage to an animal as a means of “immune conservation” during viral infections is discussed.
Antigen, host and adjuvant requirements for induction of hyperacute experimental autoimmune encephalomyelitis
Authors: Lennon Vanda A. , Westall F. C. , Thompson Millie , Ward Elsie 
Published: February 2007

AbstractA hyperacute form of experimental autoimmune encephalomyelitis (HEAE) was induced in Lewis rats using small doses (3.2 μg) of guinea pig myelin basic protein as immunogen and B. pertussis vaccine as adjuvant. Myelin basic proteins from species other than guinea pig (rat, man, monkey, pig, ox, rabbit and sheep) induced only ordinary EAE with this adjuvant. HEAE was more readily distinguished from ordinary EAE by clinical criteria (early onset, with a rapid and severe course, and high incidence of cerebral signs and mortality) than by histologic signs which, although characteristic of HEAE, were not pathognomonic for HEAE. HEAE was transferred to x‐irradiated syngeneic recipient rats with lymph node cells from appropriately immunized donors. The Brown Norway (BN) strain of rat was found susceptible to induction of ordinary EAE, but not HEAE, using large doses of either rat or guinea pig myelin basic proteins. The unique immunogenicity of the guinea pig basic protein must be due to a different antigenic determinant from the determinant(s) which is shared by rat and guinea pig myelin basic proteins and which without B. pertussis induces ordinary EAE. The adjuvant action of B. pertussis in inducing HEAE in the Lewis rat is most likely mediated through an immunocompetent T lymphocyte.
Differences in effect of isoproterenol stimulation on levels of cyclic AMP in human B and T lymphocytes
Authors: Niaudet P. , Beaurain Geneviève , Bach Marie‐Anne 
Published: February 2007

AbstractThe level of cyclic AMP (CAMP) in human lymphocytes in the presence or absence of isoproterenol stimulation was studied in various lymphocyte subpopulations containing different proportions of B and T lymphocytes.Lymphocytes from thymus and peripheral blood (which contain a majority of T cells) were more sensitive to isoproterenol action than lymphocytes from tonsils or adenoids (where B cells are predominant). Using purified B or T lymphocytes from peripheral blood, tonsils or adenoids, we observed an absence of B lymphocyte response to isoproterenol, whereas T lymphocytes, which had a lower basal cAMP level than B cells, exhibited in all experiments a significant increase in cAMP content after isoproterenol stimulation. The intensity of the response varied in the different T lymphocyte subpopulations.
The ontogeny of B lymphocytes. III. Opposite signals transmitted to B lymphocyte precursor cells by inducing agents and hormones
Authors: Hämmerling U. , Chin Ann F. , Abbott Joan , Goldstein G. , Sonenberg M. , Hoffmann M. K. 
Published: February 2007

AbstractPresent evidence supports the idea that agents inducing phenotype conversion in B and T precursor cells can be obtained from many sources (e.g. LPS, cate‐cholamines, prostaglandin E1, and DB cyclic AMP). They share the feature of raising intracellular cyclic AMP in some systems. Our experiments have demonstrated another class of components (carbamyl choline, insulin, human growth hormone, 8‐bromo‐cyclic GMP) which inhibit induction of phenotype conversion in early B lymphocyte precursor cells. All of these substances are known or suspected to raise levels of intracellular cyclic GMP. The blocking effect is transient as precursor cells regain inducibility after removal of the inhibitor within 2 to 4 h. Thymopoietin (TP), which is a selective inducing agent for conversion of prothymocytes (Thy‐1 −) to thymocytes (Thy‐1+), inhibited the induction of expression of B cell markers, Ig and Ia. Conversely, tumor necrotizing serum (TNS), which selectively induces B precursor cells (Ig− → Ig+ and Ia− → Ia+), inhibited the inducing effect of TP on prothymocytes. We propose that induction requires interaction of a specific inducing hormone with a receptor associated with adenylate cyclase, whereas inhibition of induction requires interaction with a receptor which activates guanylate cyclase. Our data indicate that prothymocytes and pro‐B cells have receptors for both TP and TNS, which are, however, associated with different signal mechanisms in B and T precursor cells. The manner in which a given precursor cell responds depends less on the specificity of hormone receptor interaction than on pre‐set receptor associations to deliver stop or go signals. This system can be regarded as a model for regulation of T and B cell differentiation by pairs of hormones with opposing effects.