bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amino acid sequence of a phosphocholine-binding antibody from an immune defective CBA/N mouse employing the T15 VH region associated with unusual DH, JH, and V kappa segments.
Authors: Clarke S H , Kenny J J , Sieckmann D G , Rudikoff S 
Published: December 2022

Abstract
Mice expressing the xid gene exhibit an altered immune response to phosphocholine (PC)-conjugated keyhole limpet hemocyanin (KLH). Less than 25% of their anti-PC-KLH response is PC specific, and most of these antibodies lack the normally predominant T15 idiotype. These findings suggested that immune defective mice might employ different variable region genes than normal mice in their anti-PC response. To examine this possibility, we characterized by Southern blot analysis the gene family encoding PC-VH regions and determined the amino acid sequence and fine specificity of binding of a T15-, IgG2, PC-specific hybridoma (1B8E5) produced by fusion of the SP2/O cell line and PC-KLH immune CBA/N spleen cells. Southern blot analysis of DNA from CBA/N mice by using a PC-VH probe (S107 VH) revealed a hybridization pattern virtually identical to that of DNA from normal CBA/J mice, indicating that CBA/N mice do not suffer from a gross deletion of PC-VH genes. Analysis of the 1B8E5 antibody reveals that both the binding specificity and relative affinity of this antibody are different from the anti-PC antibodies of the T15, M167-M511, and M603 families. The complete amino acid sequence of the heavy (H) chain variable region shows that 1B8E5 uses a VH segment identical to the allelic form of T15 (C3) but has a unique D region of three amino acids and use the JH1 joining segment. Both the DH and JH regions are unusual when compared to PC-specific antibodies from normal mice, which have a D region composed of five to eight amino acids and use the JH1 joining segment. The amino terminal sequence of the 1B8E5 light (L) chain demonstrates that this anti-PC antibody carries a Vk3 subgroup L chain. Chains from this subgroup have not previously been found in association with PC-binding antibodies. Thus, the Vk, DH, and JH segments expressed in 1B8E5 make this hybridoma unique in terms of the anti-PC antibodies studied to date, and suggests that additional PC-specific antibodies exist in inbred mice that employ "unusual" V gene segments.
Regulation of IgM and IgD synthesis in B lymphocytes. I. Changes in biosynthesis of mRNA for mu- and delta-chains.
Authors: Yuan D , Tucker P W 
Published: December 2022

Abstract
Although IgD is expressed on the surface of resting B cells at a higher density than IgM, we determined that both the steady-state level and the biosynthetic rate of mu m-mRNA is higher than that of delta m-mRNA, suggesting that translational or post-translational processing of the Ig heavy chains may modulate the expression of cell surface Ig. After B cell activation by LPS, delta m-mRNA decreases drastically, accounting for the observed decrease in expression of IgD. Concomitantly, a dramatic increase in the level of mu s- and gamma s-mRNA corresponds to the observed increase in secretion of these Ig isotypes in LPS-stimulated cells.
Enhanced TNP-reactive helper T cell activity and its utilization in the induction of amplified tumor immunity that results in tumor regression.
Authors: Fujiwara H , Moriyama Y , Suda T , Tsuchida T , Shearer G M , Hamaoka T 
Published: December 2022

Abstract
The present study was designed to investigate the generation of trinitrophenyl (TNP)-reactive helper T cell activity potent enough to induce the regression of a syngeneic tumor; this occurs by augmenting antitumor-specific immunity through T-T cell interaction. Mice whose skin was painted with trinitrochlorobenzene (TNCB) exhibited a variety of anti-TNP T cell responses, including delayed-type hypersensitivity (DTH) and cytotoxic T cell responses, as well as helper T cell activity. Pretreatment of C3H/He mice with TNP-conjugated copolymer of D-glutamic acid and lysine (TNP-D-GL) or cyclophosphamide, which have been shown, respectively, to inactivate TNP-specific suppressor T cells or suppressor T cells in general, exhibited a slight or marginal augmentation of DTH and cytotoxic potentials when tested 5 wk after TNCB painting. In contrast, the same pretreatment regimens induced an appreciably amplified generation of anti-TNP helper T cell activity. This amplified TNP-helper T cell activity was demonstrated to enhance cytotoxic responses to antigens other than TNP in an antigen-nonspecific way. In fact, such helper T cells enhanced antitumor CTL responses when co-cultured with spleen cells from syngeneic X5563 plasmacytoma-bearing mice in the presence of TNBS-modified X5563 tumor cells. This amplified TNP-helper cell system was utilized for its immunotherapeutic potential. When TNCB was injected into X5563 tumor mass of syngeneic C3H/He mice in which the amplified TNP-helper T cell activity had been generated, an appreciable number of growing tumors was observed to regress. This contrasted with the low incidence of tumor regression observed in mice in which TNP-helper activity had been induced by TNCB painting without inactivation of suppressors. Thus, the present model provides an effective immunotherapeutic manipulation for eliciting enhanced in vivo tumor regression, and emphasizes a role of helper T cells in augmentation of syngeneic tumor immunity.
Antigen-reactive cloned helper T cells. I. Unresponsiveness to antigenic restimulation develops after stimulation of cloned helper T cells.
Authors: Wilde D B , Fitch F W 
Published: December 2022

Abstract
Murine helper T lymphocyte (HTL) clones reactive to ovalbumin (OVA) were maintained in continuous culture in vitro. Clones were propagated by weekly stimulation in the presence of irradiated splenic filler cells, antigen, and supernatant fluid (SF) containing IL 2. By varying the quantity of these reagents in cultures of HTL cells, the reactivity to antigen of the cloned cells was altered markedly. After stimulation by antigen or SF, HTL clones became profoundly unresponsive to antigenic restimulation. Cells remained unresponsive for 2 to 9 days after stimulation, depending on the culture conditions that were chosen for their maintenance. The addition of SF containing a high concentration of IL 2 prolonged the duration of unresponsiveness by 3 days, and the presence of a non-T splenic filler cell increased the period of unresponsiveness by an additional 4 days. The use of a high concentration of OVA in cell cultures also prolonged the time of unresponsiveness. The results described here demonstrate that the response to antigen of HTL cells is down-regulated after stimulation, and appears to be correlated with exposure to SF that contains IL 2.
A reappraisal of "T-independent" antigens. II. Studies on single, hapten-specific B cells from neonatal CBA/H or CBA/N mice fail to support classification into TI-1 and TI-2 categories.
Authors: Nossal G J , Pike B L 
Published: December 2022

Abstract
Spleen cells from adult CBA/H or CBA/N mice, or from neonatal CBA/H mice, were fractionated on thin layers of fluorescein (FLU)-gelatin to yield FLU-specific B lymphocytes. A single cell, or small numbers ranging from 1 to 10, were cultured in 10-microliter microcultures together with various antigens and mitogens. The results were compared with those of bulk culture or limiting dilution cultures supported by thymus filler cells. B cell growth and differentiation-promoting conditioned media (BGDA) were added to some cultures. The CBA/N results gave no support to the commonly used classification of T cell-independent (TI) antigens into TI-1 and TI-2 categories. A typical supposed TI-1 antigen, FLU-LPS, strongly stimulated normal adult single FLU-specific B cells to proliferate and form antibody, but virtually failed to trigger CBA/N B cells of comparable antigen-binding avidity. The same was true of LPS or LPS plus dextran sulfate acting as mitogens. The allegedly TI-2 antigen FLU-Ficoll, although still triggering comparatively poor responses, was actually marginally more active than FLU-LPS. FLU-Brucella abortus (FLU-BA) + BGDA gave the best results with single CBA/N B cells, but still induced only 1.27% of cells to develop into antibody-forming clones vs 12.2% with CBA/H cells. The results obtained with single neonatal B cells also lent no support to the distinction between TI-1 and TI-2. Both "TI-1" and "TI-2" stimuli caused adequate proliferation, one "TI-2" antigen stimulating 23.2% of the cells. None of the antigens caused good antibody formation, however, probably because multivalent antigens can deliver signals impeding the differentiation of immature B cells. It is therefore suggested that the classification of TI-1 antigens into two subcategories be abandoned, at least for the time being.
Avian thymic accessory cells.
Authors: Oliver P D , LeDouarin N M 
Published: December 2022

Abstract
On the basis of morphologic criteria and ingestion of latex particles, two basic types of accessory cells can be identified from quail and chick thymuses, dendritic cells, and macrophages. By using embryonic grafting techniques, we show that cells of this lineage enter the thymus during the initial colonization of the epithelial thymic rudiment by hemopoietic cells, and within a few days differentiate into cells exhibiting properties of glass adherence, Ia expression, and formation of rosettes with thymocytes. It appears that the precursors of this lineage undergo extensive, but finite, proliferation and are eventually replaced by further influx of the accessory cell lineage. In chimeric grafts, quail thymocytes were seen forming rosettes with chick accessory cells, and vice versa, indicating, as in the interaction between the epithelial cells and thymocytes, that the molecules involved in thymocyte-accessory cell association can interact across species barriers in our system.
Deoxyadenosine modulates human suppressor T cell function and B cell differentiation stimulated by Staphylococcus aureus protein A.
Authors: Cohen A H , Bluestein H G , Redelman D 
Published: December 2022

Abstract
Adenosine deaminase (ADA) deficiency and the resultant accumulation of deoxyadenosine (AdR) are associated with profound T cell dysfunction and variable B cell dysfunction in vivo. We examined the effects of AdR on the in vitro function of normal human peripheral blood B and T lymphocytes whose ADA activity was inhibited by 2'-deoxycoformycin. We found that OKT8+ T cell-mediated suppression of SPA-induced Ig production was markedly reduced by concentrations of AdR (3 to 10 microM) that did not affect helper T cell function. Because the lectin-induced proliferative responses of OKT8+ T cells and OKT8- T cells were equally susceptible to AdR, modulation of in vitro immune responses by low-dose AdR probably reflected different proliferative requirements for the expression of T cell helper or suppressor functions. Although low doses of AdR did not inhibit Ig production in SPA-stimulated cultures, we found that T cell-dependent, SPA-stimulated B cell proliferation was blocked by 3 to 10 microM AdR. Therefore, it appeared that B cell proliferation was not required for the induction of Ig synthesis in this system. Higher doses (30 to 100 microM) of AdR did block the induction of Ig synthesis, presumably by interfering with T-helper functions via a mechanism other than inhibition of proliferation and/or by inhibiting B cell differentiation events.
Lymphocyte ecto-5'-nucleotidase activity in infancy: increasing activity in peripheral blood B cells precedes their ability to synthesize IgG in vitro.
Authors: Bastian J F , Ruedi J M , MacPherson G A , Golembesky H E , O'Connor R D , Thompson L F 
Published: December 2022

Abstract
Ecto-5'-nucleotidase activity was measured in peripheral blood lymphocytes isolated from serial specimens from nine healthy full-term infants and two premature infants at 0, 2, 4, and 6 mo of age. The postnatal nadir in activity was 7.1 +/- 2.0 nmol/hr/10(6) cells, which is the same as the activity in cord blood lymphocytes (7.0 +/- 2 nmol/hr/10(6) cells). The activity rose twofold to 13.2 +/- 3.8 nmol/hr/10(6) cells at 6 mo of age (p less than 0.001, paired t-test), which is similar to the activity in adult peripheral blood lymphocytes (14.1 +/- 6.3 nmol/hr/10(6) cells). This increased activity in total lymphocytes reflects increased activity in the B cell population. B cell ecto-5'-nucleotidase activity in two infants at 12 to 13 mo of age was 19.3 and 25.2 nmol/hr/10(6) cells, values that are four-to fivefold higher than for cord blood B cells (5.6 +/- 2.8 nmol/hr/10(6) cells) and within the normal range for adult B cells (27.9 +/- 12 nmol/hr/10(6) cells). In spite of a greatly expanded peripheral blood B cell population, studies of immunoglobulin biosynthesis in vitro demonstrated that infant peripheral blood B cells are functionally immature with no synthesis of IgG in response to Epstein Barr virus. Thus, the increase in peripheral blood B lymphocyte ecto-5'-nucleotidase activity in infants precedes their acquisition of a capacity for IgG synthesis in vitro. Data from a hypogammaglobulinemic infant revealed a persistently low ecto-5'-nucleotidase activity over a 10-mo period until at 14 mo of age the activity was 8.8 nmol/hr/10(6) cells in total lymphocytes and 13.0 nmol/hr/10(6) cells in B cells, which correlated with in vivo and in vitro evidence of delayed B cell maturation. Thus, ecto-5'-nucleotidase activity may be a useful cell surface marker in studies of human postnatal B cell maturation.
Differential inhibition of human antigen-specific T cell clone proliferative responses by distinct monoclonal anti-HLA-DR antibodies.
Authors: Triebel F , Missenard-Leblond V , Couty M C , Charron D J , Debre P 
Published: December 2022

Abstract
The inhibition of diphtheria toxoid and varidase-specific T cell clones from a single DR 6/7 donor by eight distinct monoclonal anti-HLA-DR antibodies was tested in proliferative assays. These moAb were selected because they had been previously defined for their ability: 1) to react with Ia molecules; 2) to recognize similar or different epitopes; 3) to share or not share idiotypic specificities. Our results show a distinct inhibition pattern for each clone tested. Furthermore, the various moAb could be classified into three groups according to their inhibitory effect on T cell proliferation. These data suggest: a) an epitopic restriction by class II antigens of antigen-specific human T cell clone proliferation; and b) the recognition of functional epitopes on the human Ia-like antigens by some but not all moAb studied.
Lysosomal enzyme release from polymorphonuclear leukocytes induced by immune complexes of IgM and of IgG.
Authors: Lucisano Y M , Mantovani B 
Published: December 2022

Abstract
Lysosomal enzyme release by rabbit polymorphonuclear leukocytes induced by immune complexes of IgM or IgG antibodies and ovalbumin was studied by in vitro experiments. It was shown that IgM immune complexes in the form of precipitates were able to stimulate the release of the lysosomal enzymes beta-glucuronidase and alkaline and acid phosphatases, in contrast to heat-aggregated IgM, which had only a small effect. This stimulation was dependent on the presence of Ca2+ in the extracellular medium; Mg2+ showed a slight effect as a substitute for Ca2+. IgG precipitated immune complexes prepared from different regions of the precipitation curve were tested. It was shown that immune precipitates from the equivalence region were the most effective; those at antibody excess have a smaller but comparable capacity, whereas the precipitated immune complexes at antigen excess were the least effective. Soluble immune complexes of IgG with an excess of antigen concentration in the range of 2.5 to 5 times that of equivalence were also able to stimulate the enzyme release, but that capacity decreased rapidly with the increase in antigen concentration. The enzyme release induced by IgM immune complexes was not inhibited by competition with free immunoglobulin in the medium, either IgM or IgG in approximate physiologic concentrations; contrarily, with IgG immune complexes, free monomeric IgG (but not IgM) can completely block the process. The possible implications of these findings in the immune complex diseases are discussed.
Suppression of NK-mediated natural resistance by interferon treatment of murine lymphomas.
Authors: Greenberg A H , Miller V , Jablonski T , Pohajdak B 
Published: December 2022

Abstract
The observation that interferon (IFN) can suppress the NK lytic sensitivity of murine lymphomas in vitro led us to examine the consequences of this treatment on tumor behavior in vivo. Preincubation in IFN suppressed natural resistance to two lymphomas in syngeneic DBA/2 and semisyngeneic BDF1 mice in a dose-dependent manner, measured by the retention of (131I)dUrd-labeled tumor. Poly I:C enhancement of NK-mediated natural resistance in the lung, liver, and peritoneal cavity was also abolished by IFN pretreatment. IFN was, however, ineffective in altering the elimination of the IFN-resistant L1210R lymphoma when compared to its IFN-sensitive variant, L1210S. In DBA/2 mice that were made NK-deficient by treatment with cyclophosphamide or rabbit anti-asialo GM1 antiserum, or in congenitally NK-deficient bg/bg strain mice, IFN-treated tumor and control tumor were rejected equally well. This indicated that the effects of IFN were dependent on the presence of NK cells in these mice, and suggests that the IFN suppressed the sensitivity of the lymphomas to NK cell-mediated host resistance.
Phorbol ester increases the level of interleukin 2 mRNA in mitogen-stimulated human lymphocytes.
Authors: Hirano T , Fujimoto K , Teranishi T , Nishino N , Onoue K , Maeda S , Shimada K 
Published: December 2022

Abstract
TPA alone did not induce the production of IL 2 in human tonsillar lymphocytes but enhanced the PHA-induced IL 2 production by seven-fold. That the effect of TPA was due to an increase in IL 2 mRNA was demonstrated by examining the amount of IL 2 mRNA translatable in Xenopus laevis oocytes, and by Northern blotting analysis using IL 2 cDNA as a probe. In these ways, it was shown that TPA alone did not induce any significant IL 2 mRNA synthesis, but when added together with PHA it increased the level of IL 2 mRNA by at least 10-fold, as compared with that induced by PHA alone.
Phosphorylcholine on Streptococcus pneumoniae R36a is responsible for in vitro polyclonal antibody secretion by human peripheral blood lymphocytes.
Authors: Beckmann E , Levitt D 
Published: December 2022

Abstract
We have shown that Pc on the C-polysaccharide of Streptococcus pneumoniae R36a is responsible for polyclonal PFC responses induced in vitro by this bacterium in humans. R36a grown in media containing EA instead of CL, and therefore having phosphorylethanolamine instead of Pc in their C-polysaccharide, were unable to induce substantial PFC responses. When EA-substituted bacteria were chemically conjugated with Pc, their ability to induce polyclonal PFC was restored. Specific removal of Pc from the surface of the bacteria by the use PLC also resulted in abrogation of the polyclonal antibody response. These data are consistent with our hypothesis that polyclonal activation resulting from R36a stimulation may be mediated by a recently described Pc-binding receptor that is distributed on the surface of a subpopulation of B lymphocytes in humans and mice.
The effect of deoxyguanosine on human lymphocyte function. I. Analysis of the interference with lymphocyte proliferation in vitro.
Authors: Spaapen L J , Rijkers G T , Staal G E , Rijksen G , Wadman S K , Stoop J W , Zegers B J 
Published: December 2022

Abstract
The effect of deoxyguanosine on mitogen- and antigen-induced proliferation of peripheral blood lymphocytes from healthy donors was studied. Deoxyguanosine was found to inhibit the proliferative response to mitogens and antigens. Concentrations of deoxyguanosine causing 50% inhibition of the proliferation proved to be dependent on the activity of catabolic enzymes, such as purine nucleoside phosphorylase (PNP), in sera used in the culture media. The inhibitory effect of deoxyguanosine on phytohemagglutinin (PHA)-induced cell proliferation was prevented by deoxycytidine as well as by hypoxanthine. These findings were analyzed further by determination of intracellular (deoxy)-nucleotide levels. Stimulation of lymphocytes by PHA in the presence of deoxyguanosine leads to intracellular accumulation of dGTP. The presence of hypoxanthine in addition to deoxyguanosine abolished the inhibitory effect but did not prevent dGTP accumulation. On the other hand, the addition of deoxycytidine in combination with deoxyguanosine did not lead to intracellular accumulation of detectable amounts of dGTP, but only gave partial protection against the toxic effect. Furthermore, guanosine inhibited mitogen-induced cell proliferation to the same extent as did deoxyguanosine provided that the culture media were supplemented with pretreated fetal calf serum. Peripheral blood lymphocytes of a PNP-deficient or a HGPRT-deficient patient in cultures stimulated with PHA or pokeweed mitogen were resistant to the inhibitory effects of guanosine and were less sensitive to deoxyguanosine than cells of normal donors. The present results clearly show the involvement of two pathways contributing to deoxyguanosine-mediated inhibition of the proliferation of normal lymphocytes, i.e., on the one hand degradation of deoxyguanosine by PNP, salvage of guanine by HGPRT, and (possibly) phosphorylation of GMP eventually leading to GTP, and on the other hand formation of dGTP by direct phosphorylation of deoxyguanosine by deoxycytidine kinase.
Partial immunochemical characterization of the Ro and La proteins using antibodies from patients with the sicca syndrome and lupus erythematosus.
Authors: Elkon K B , Culhane L 
Published: December 2022

Abstract
Ro and La are intracellular ribonucleoproteins that are frequent targets for autoantibodies in the sicca syndrome and in lupus erythematosus. We analyzed the m.w. of the protein (antigen) moieties of Ro and La in saline cell extracts of human spleen by SDS-PAGE and immunoblotting, gel filtration, and sucrose density ultracentrifugation with radioimmunoassay. pI values for Ro and La proteins were established by isoelectric focusing on thin layer agarose gels and immunoblotting on nitrocellulose transfers. The La protein had an m.w. of approximately 43 kd and was heterogeneous in charge, with pI values from 4.2 to 4.8. Composite two-dimensional maps developed by immunoblotting revealed a characteristic set of seven dots of m.w. 43 kd. Ro determinants were identified on polypeptides of 50 and/or 57 kd. Antigenic activity was also detected in the void volume of spleen extract fractionated by Sephadex G-200 and in 8 to 9S and greater than 19S regions of sucrose gradients, suggesting either aggregation of the Ro protein or participation in protein-protein complexes. pI values of 4.3 to 5.5 were obtained for the Ro antigen, and two-dimensional maps revealed that the 57 kd polypeptide had a similar charge heterogeneity to the La protein, whereas the 50 kd polypeptide had a different fingerprint. Immunoblotting of extracts from bovine, rabbit, and dog extracts showed that antibodies to Ro and La reacted with a limited number of polypeptides (m.w. 50 and/or 57 kd for anti-Ro and 43 or 50 kd for anti-La). These studies support the physical independence of the isolated Ro and La polypeptides, although a precursor product or functional relationship in vivo is possible. These studies also suggest that, in addition to Western blotting, techniques involving immunodeletion, isoelectric focusing with capillary immunoblotting, and 2D immunoblotting provide useful approaches to characterize saline-soluble cellular antigens.