bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of serum factors in the stimulation of human umbilical cord and fetal lymphocytes by soluble protein A from Staphylococcus aureus
Authors: Turunen Olli 
Published: February 2007

AbstractHuman umbilical cord and fetal lymphocytes were cultured in the presence of various sera [AB serum, fetal calf serum (FCS) and gammaglobulin‐free FCS] and soluble protein A from Staphylococcus aureus (SpA). Dose response studies showed that SpA in a final concentration of 100 μg/ml stimulated moderately cord blood lymphocytes. SpA‐induced DNA synthesis was significantly higher when cord lymphocytes were cultured with FCS than with AB serum or gammaglobulin‐free FCS. After 6 days' culture, even SpA without serum became a potent mitogen for these cells. The peak values for incorporation of thymidine into cord lymphocytes depended on the concentration of SpA and the serum used for culture. However, fetal splenocytes, thymocytes and peripheral lymphocytes reacted more avidly with SpA in cultures containing AB serum than FCS. Furthermore, serum‐free SpA cultures did not result in any activation of fetal lymphocytes. Regardless of whether cord blood lymphocytes were cultured with AB serum or FCS, both T and B subpopulations were stimulated. In contrast to fetal cells, the response of cord cells was stronger with FCS, and the peak values were shifted to later culture days.In conclusion, SpA acts as a mitogen both on T and B cells in early fetuses as well as in the newborn. Serum factors significantly influence the strength and kinetics of the mitogenic response.
Helper activity of T cells stimulated in long‐term culture
Authors: Julius Michael H. , Augustin Andrei A. 
Published: February 2007

AbstractThymus‐derived (T) cells obtained from three categories of in vitro antigen‐induced proliferative responses were assayed as sources of helper T cells. These categories are exemplified by (a) direct stimulation of keyhole limpet hemocyanin (KLH)‐primed cells with KLH, which results in high indexes of proliferation; (b) direct stimulation of apoferritin‐primed cells with apoferritin, which does not result in indexes of proliferation above background levels; (c) trans‐stimulation of unprimed cells with X‐irradiated KLH‐primed cells which results in indexes of proliferation comparable to category (a).Our results indicate that levels of [3H]thymidine incorporation by proliferating populations are not an accurate reflection of helper T cell generation. Directly stimulated KLH and apoferritin‐primed cells give rise to highly enriched populations of antigen‐specific helper T cells which support both IgM and IgG antibody responses in vitro. Moreover, these specific helper T cells are functionally restricted by products encoded by the I region of the major histocompatibility complex (MHC). Helper T cells generated in KLH‐trans‐stimulated cultures are not KLH‐specific in that comparable levels of helper activity are expressed using either KLH or apoferritin as carriers. These non‐KLH‐specific helper T cells only support the production of IgM antibody in vitro and they are not functionally restricted by MHC products.
Amino acid sequence analysis of group e allotype‐ related peptides derived from lagomorph IgG
Authors: Teherani Jane , Capra J. Donald , Aggarwal Shanti , Mandy William J. 
Published: February 2007

AbstractA tryptic peptide (T19) was isolated from a CNBr fragment of IgG from several representatives of present‐day lagomorphs including domestic rabbit, hare, cottontail rabbit and pika. The amino acid sequence of this peptide revealed differences which can be correlated with serological polymorphism associated with group e IgG allo‐ types. The results confirm previous studies establishing the importance of Ala309 for the expression of e 15, particularly the i subspecificity. Arg315 correlates with the expression of the j subspecificity.
Regulation of the specific plaque‐forming cell responsein man: Restraint of B cell responsiveness
Authors: Dosch Hans‐Michael , Shore Abraham , Gelfand Erwin W. 
Published: February 2007

AbstractSpecific in vitro plaque‐forming cell (PFC) responses of normal human lymphocytesare antigen dose‐dependent, with bell‐shaped dose response patterns. Both the bell‐shaped antigen dose response characteristics as well as optimal PFC responseamplitudes are dictated by two distinct and separable T lymphocyte subpopulationswhich act on a nonlimiting set of PFC precursor B cells. Specific theophylline‐sensitive suppressor and theophylline‐resistant helper T cells are activated by antigen in adose‐dependent fashion. The initially small suppressor cell pool expands exponentially following antigen contact, whereas the larger helper cell population does not. This leaves a restricted range of antigen concentrations where net helper activity issufficient to promote a PFC response. Due to coinduced suppressor activity, PFCresponses showed an overall negative restraint at all antigen concentrations. Limitingdilution analysis suggested that it is the numerical balance between the two alternative T cell subsets which determines the extent of this negative restraint. These datadelineate a cellular mechanism for the translation of an antigenic stimulus into a B cellantibody response; theophylline‐sensitive suppressor cells are able to expand inresponse to this stimulus and represent the main regulative vector. Thus, in mixedlymphocyte populations, antigen concentration is a valuable probe for studies of thebalance of discrete T cell subpopulations but not for absolute B cell responsiveness.
Induction and characterization of delayed‐type hypersensitivity to influenza virus in mice
Authors: Liew Foo Y. , Russell Stuart M. , Brand Colin M. 
Published: February 2007

AbstractMice infected with an aerosol of influenza virus or immunized with purified UV‐ inactivated whole virus or viral subunits developed delayed‐type hypersensitivity (DTH) to influenza virus. The level of DTH was greatly enhanced when mice were injected intraperitoneally 2 days prior to immunization with 200 mg/kg of cyclophosphamide. The reaction peaked at 24 h after elicitation, had the classical DTH histology, and was transferable by immune cells but not by immune serum. DTH induced in cyclophosphamide‐pretreated mice persisted for at least 40 days after sensitization. DTH induced by deoxycholate‐treated subviral particles (DC particles) or the matrix protein of the influenza virus was type‐specific, i.e. DTH induced by DC particles or matrix protein of type A virus cross‐reacted only with type A virus and not with type B virus. DTH induced by purified hemagglutinin (HA) subunits, on the other hand, showed subtype specificty. Thus, DTH induced by HA of X 31 virus (H3) did not cross‐react with PR 8 virus (H 0). However, DTH induced by HA of one subtype cross‐reacted significantly with the variants of the same subtype. Thus, it appears that the effector T cells of DTH do not discriminate between the antigenic variants of influenza virus that are distinguishable by serology. DTH induced by purified, UV‐ inactivated whole virus showed extensive cross‐reactivity. This nonspecific reaction was shown to be due to host‐derived material, the lipid bilayer. ‐ The theoretical and practical implications of these findings are discussed.
Neonatal expression of a cross‐reactive idiotype associated with anti‐phenylarsonate antibodies in strain A mice
Authors: Nutt Nan B. , Wiesel Andrea N. , Nisonoff Alfred 
Published: February 2007

AbstractData are presented which indicate that B cells expressing the cross‐reactive idiotype associated with anti‐p‐azophenylarsonate antibodies of A/J or allotype‐congenic C.AL‐20 mice are present in neonatal mice. Data were obtained by direct immunization of neonatal mice or by adoptive transfer of cells from neonatal C.AL‐20 mice into idiotype‐negative BALB/c recipients. These findings, together with those previously reported for antibodies to phosphocholine in BALB/c mice, support the generalization that major cross‐reactive idiotypes may usually be found early in the life‐span of a mouse. The contrast between the frequency of appearance of the major cross‐reactive idiotypes and “private” idiotypes with the same antigen‐binding specificity, which are found after immunological suppression of the major idiotype, is consistent with the possibility that cross‐reactive idiotypes are the product of germ line genes or minor somatic variants of germ line genes while private idiotypes arise through somatic diversification. Alternatively, regulatory mechanisms may account for the striking difference. The present results are therefore consistent with the early expression of germ line genes controlling the major idiotype or of corresponding regulatory genes. The average concentration of idiotype, per unit weight of anti‐phenylarsonate antibody, is somewhat lower in neonatal than in adult A/J mice indicating that the major idiotype does not account for all of the antibody produced in response to this hapten in the neonate.
Ontogeny of immunity in amphibians: Changes in antibody repertoires and appearance of adult major histocompatibility antigens in Xenopus
Authors: Du Pasquier Louis , Blomberg Bonnie , Bernard Claude C. A. 
Published: February 2007

AbstractLarval Xenopus anti‐2, 4‐dinitrophenyl antibodies of the low‐molecular weight type can be analyzed by isoelectric focusing (IEF). Within a clone of genetically identical animals, tadpoles make antibodies whose IEF spectrotypes are shared by most of the individuals. Adults of the same clone also make antibodies of identical spectrotype, but the adult pattern can be very different from the larval one, although both responses are heterogeneous. The larval spectrotypes that one cannot see in a primary adult response can be found if the adult has been primed during larval life and boosted after metamorphosis. The heterogeneity of the response is somewhat lower in tadpoles (up to 12 antibody IEF bands) than in adults (up to 20 antibody IEF bands). The change in the repertoire occurs during metamorphosis at the time of the appearance of two major histocompatibility complex antigens. One, a lymphocyte antigen, appears 10‐15 days before the end of metamorphosis, the other, present on red cells (and presumably also on lymphocytes), appears 1.5 month after the end of metamorphosis, as determined by immunofluorescence analysis. During the same period, the syngeneic mixed leukocyte reaction switches from a larval anti‐adult to an adult anti‐larval reaction.
Characteristics of the T‐dependent α(1 → 6) glucosyl (dextran) antibody response induced in mice with isomaltohexaose coupled to chicken γ‐globulin
Authors: Moreno Carlos , Hale Christine , Hewett Rosemary , Cussell Deborah 
Published: February 2007

AbstractIsomaltohexaose flavazole coupled to chicken γ‐globulin (IM6‐CGG) induced T celldependent anti‐α( 1 → 6) dextran‐specific IgM and IgG responses in CBA, BALB/c and A strain mice. The IgG responses were of restricted heterogeneity as judged by isoelectric focusing, and belonged mostly to the IgG1 subclass with a minor IgG3 component in the case of BALB/c and CBA mice. All four subclasses of IgG were produced in A strain mice. In contrast, native dextran B 512 induces exclusively T cell‐independent IgM responses of the same specificity for all 3 strains.All BALB/c mice immunized with different doses of IM6‐CGG either in Freund's adjuvant or with A1(OH)3 plus Bordetella pertussis showed the same spectrotypes by isoelectric focusing. Sera obtained at different times after immunization of BALB/c mice failed to show spectrotype variations. Late, but not early, bleedings from CBA mice showed a tendency towards more uniform isoelectric focusing patterns.
A mature T lymphocyte subpopulation marker closely linked to the Ig‐1 allotype CH locus
Authors: Owen Frances L. , Finnegan Alison , Gates Edward R. , Gottlieb Paul D. 
Published: February 2007

AbstractAn antiserum raised in BALB/c AnN mice against selected CAL.20 T cells reacts with a cell surface antigen in virgin animals that is found on 25% of mature thymocytes and Lyt‐2‐bearing T cells, but not on prothymocytes, Lyt‐1 T cells or B cells. The antigen is restricted to strains carrying the Ig‐ld or Ig‐le heavy chain allotype haplotypes. It is expressed in F1 mice. The antiserum blocks the binding of suppressor T cells to the cross‐reacting idiotype for arsonate while reagents specific for Fab, Fc or Ig were ineffective. We suggest that the antigen described represents a determinant on the product of a new locus coding for a heavy chain‐linked polypeptide found on a subpopulation of T cells.
Partial N‐terminal amino acid sequence analyses and comparative tryptic peptide maps of murine Ia molecules encoded by the I‐A subregion
Authors: Cecka J. Michael , Millan Minnie Mc , Murphy Donal B. , McDevitt Hugh O. , Hood Leroy 
Published: February 2007

AbstractThe partial N‐terminal amino acid sequences and tryptic peptide maps of I‐A subregion products from the H‐2b, H‐2d, H‐2k and H‐2S haplotypes demonstrate that haplotype‐associated differences are present in both a and β polypeptides. The genetic and evolutionary implications of these multiple amino acid substitutions and the homology relationships among Ia molecules from human, guinea pig and the I‐E subregion of the mouse are discussed.
Radioimmunoassay determinations of murine β2‐microglobulin and an H‐2 antigen‐like serum component
Authors: Kvist Sune , Peterson Per A. 
Published: February 2007

AbstractNormal mouse serum contains H‐2 antigen‐like components. One such protein consists of a 40000 dalton chain and β2‐microglobulin (β2m) and the other component contains the two H‐2 antigen‐like subunits and, in addition, two larger polypeptide chains with apparent molecular weights (mol. wt.) of 65000 and 80000. Radioimmunoassay procedures specific for the H‐2 antigen‐like chain and β2m, respectively, have been developed. Whereas free β2m and β2m associated with other polypeptide chains reacted identically in the β2m radioimmunoassay, the two serum forms of the H‐2 antigen‐like chain displayed different reactivities in the heavy‐chain assay. The low mol. wt. protein complex, comprising the 40000 dalton chain and β2m, inhibited in the heavy‐chain assay identically with the standard. However, the high mol. wt. complex containing the H‐2 antigen‐like chain gave rise to a biphasic inhibition profile. This was apparently due to some antigenic determinants of the 40000 dalton chain being buried by the 65000 and 80000 dalton chains. Inhibition curves parallel with the standard were, however, obtained on dissociation of the high mol. wt. protein complex with sodium dodecyl sulfate. Thus, by subjecting serum to the ionic detergent‐sensitive radioimmunoassay, procedures for the two H‐2 antigen‐like chains could be developed.The serum levels of the H‐2 antigen‐like chain and of β2m vary with the age of the animal, and adult levels are recorded only at 6 to 7 weeks of age. The serum concentrations of the two proteins are strongly correlated. The H‐2 haplotype appears to partly regulate the serum levels of the two proteins. Mice of the H‐2f haplotype contain about 40‐fold lower levels of the H‐2 antigen‐like chain than do mice of other strains.
Surface Ig on rabbit lymphocytes Rabbit B and T cells are distinct populations
Authors: Bast Bert J. E. G. , Catty David , Manten‐Slingerland Ria , Jansen Jan T. G. , Veldhuis Dick H. , Roholl Paul , Ballieux Rudy E. 
Published: February 2007

AbstractRabbit peripheral blood lymphocytes (PBL) were analyzed by immunofluorescence using anti‐T cell conjugates and anti‐Fab, anti‐al allotype, anti‐IgM and anti‐IgA conjugates. In addition, T cells were demonstrated by rosetting with papain‐treated homologous erythrocytes. Control experiments, using acid treatment and incubation at 37 °C for 18 h after or without pronase treatment, revealed the endogenous origin of all surface determinants tested.A good correlation was found between results obtained with the two anti‐T cell conjugates used and the T rosette test on PBL and on lymphoid cells isolated from various organs. In lymphocytes isolated from peripheral blood and from various lymphoid organs, the percentages of T and B cells were respectively 45 and 38 for PBL, 10 and 46 for bone marrow, 27 and 31 for appendix, 40 and 45 for spleen, 42 and 46 for Peyer's patches, 96 and 0.3 for thymus and 70 and 16 for peripheral lymph nodes. The percentage of “null” cells in lymphocyte populations derived from bone marrow and appendix is rather high. The final percentages of T and B cells in rabbit PBL depend to a significant extent on the method of isolation, especially isolation by Ficoll‐Hypaque centrifugation results in a depletion of T cells. Moreover, a rather impure lymphoid cell suspension is obtained.In double incubation experiments, T cells (as defined by T cell antigen(s) or rosette formation) and B cells (Fab‐bearing cells) were entirely different subpopulations. Allotypes of the a locus could not be detected on the surface of T cells. The results are discussed with respect to genetic coding of antigen receptors on B and T cells.
Immunologically active zones in bovine growth hormone
Authors: Ferrara Pascual , Zakin Mario M. , Peña Clara , Paladini Alejandro C. 
Published: February 2007

AbstractAntigenic determinant areas were detected in bovine growth hormone fragments 6–124 and 125–149, the former being predominant. Reduction and carboxymethylation of disulfide bridge 53–164 destroys the immunological reactivity of the area which is little affected by reduction and carbamoylmethylation. All the activity found in fragment 6–124 seems to be concentrated in the sequence 87–124.
Regulatory circuits and antibody responses
Authors: Herzenberg Leonore A. , Black Samuel J. , Herzenberg Leonard A. 
Published: February 2007

AbstractConsideration of the interactions among cells and cell products involved in regulating antibody responses leads us to suggest that such interactions are organized into several discrete circular series (circuits) integrated with one another by virtue of shared circuit components. We see these circuits as individually concerned with particular aspects of regulation (carrier‐specific, idiotype‐specific, etc.), but together constituting an integrated, self‐governing system capable of regulating all aspects of antibody production and assuring the ordedy progress of the response (sequential idiotype representation, affinity maturation, isotype representation, overall or selective non‐ responsiveness, etc.).To illustrate how a circuit‐based regulatory system could be constructed and expected to operate, we describe four integrated circuits here: a core regulatory circuit that determines whether a given idiotype will or will not be produced and three auxiliary regulatory circuits that respond to antigen and serum antibody (idiotype) levels by switching the core regulatory circuit into a suppression or “help” mode. These circuits incorporate the idiotype‐anti‐idiotype recognition system basic to the Jerne network theory but also provide for the operation of other cognitive systems that enable specific interactions between individual circuit elements (B cells, antibody, the various suppressor and helper T cells, macrophages and soluble regulatory products). As an integrated unit, the circuits constitute a detailed “working” model that depends on relatively few assumptions and is consistent with the known interactions between elements and the known properties of responses.
Immunochemical study of the β chain of Escherichia coli tryptophan synthetase and its proteolytic fragments
Authors: Zakin Mario M. , Boulot Ginette , Goldberg Michel E. 
Published: February 2007

AbstractIt has been previously reported that a limited proteolysis by trypsin of the β2 subunit of Escherichiiz coli tryptophan synthetase produces a nearly functional dimeric protein, the protomer of which consists of two large, nonoverlapping, polypeptide fragments, F1 and F2. In the study reported here, an immunochemical comparison between the native protein, the nicked protein and its two isolated proteolytic fragments was performed, leading to the following conclusions:

The β2 subunit and the nicked protein, regardless of the presence or absence of the coenzyme pyridoxal phosphate and of the reduction of the Schiff base between the cofactor and the protein, are immunologically indistinguishable. This confirms the strong structural similarity between the intact and nicked protein.
The failure to detect a change in the immunological reactivity of intact or nicked β2 upon removal or reduction of the coenzyme suggests that pyridoxal phosphate does not play a major role as an antigenic determinant in β2 or in modification of the conformation of the apoprotein.
When the two proteolytic fragments are separated, they still cross‐react with native β2, and all the antigenic determinants of β2 are recognized either on isolated Flor on isolated F2 by antibodies directed against native β2. However, the average affinity of the antibodies for the isolated fragments is much lower than for the native or nicked protein.
The results are discussed in terms of formation and arrangement of globular intermediates during the folding of the intact protein.
Cell‐mediated anti‐tumor response in the RL♂61 system II. Control of the T killer cells by an H‐2‐linked Ir gene interfering with non‐H‐2 factors
Authors: Duprez Veronique , Belucchi Sylvia , Lévy Jean Paul 
Published: February 2007

AbstractThe generation of cytolytic T lymphocytes (CTL) during the immune response directed against the syngeneic X‐ray‐induced BALB/c RL♂ 1 leukemia has been described previously: T killer cells react with a tumor antigen of RL♂ 1 cells, and the H‐2Dd molecules of the target cells play some role in the interaction. The study of anti‐RL♂ 1 responses of [(C57BL/6 × BALB/c) × BALB/c] mice shows that the major histocompatibility complex controls the anti‐RL♂ 1 CTL reaction at a second level, through an Ir gene, with dominant responsiveness, probably mapping to the right of I‐B and controlling the high or low‐CTL responder phenotype. Another non‐ H‐Associated gene interferes with the H‐2‐linked Ir gene, a responder allele at the non‐H‐2 locus, being necessary for the expression of the high‐responder phenotype at the Ir gene locus.
Capping revisited: I. Inhibition by some thiols
Authors: Loor Francis 
Published: February 2007

AbstractThe capping, but not the clustering (spotting), of membrane immunoglobulins and of other lymphocyte membrane macromolecules is inhibited when the medium contains some reducing agents, principally cysteine. The inhibition is easily reversible, being rather a retardation of capping than its blockage. The mechanism of inhibition is still unclear, but it definitely depends on the sulfhydryl moiety of the thiols.