bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro mutagenesis of a mouse MHC class I gene for the examination of structure-function relationships.
Authors: Shiroishi T , Evans G A , Appella E , Ozato K 
Published: December 2022

Abstract
Oligonucleotide-directed, site-specific mutagenesis has been employed to elucidate the role of individual amino acids on the expression and function of a MHC class I antigen. Two oligonucleotides were synthesized to introduce single amino acid substitutions in the murine H-2Ld gene. The highly conserved glycosylation site at amino acid position 86 was changed from asparagine to lysine to remove the carbohydrate moiety from the first external domain of the H-2 molecule, and the phenylalanine at position 116 was changed to tyrosine, replacing the Ld residue with the Kb type amino acid analogous to Kb mutants: bm5 and bm16 mutants derived from the Kb antigen have the Ld-type residue at this position. The mutant genes were constructed by annealing the mutagenic oligomers to the single stranded H-2Ld gene, followed by chain elongation reaction. The expected mutations were confirmed by DNA sequence determination. The mutant genes were introduced into mouse L cells by DNA-mediated gene transfer. Both mutant genes expressed the antigens on the cell surface, as detected by antibody binding; these antigens were reactive with the cytotoxic T cells specific for the H-2Ld antigen. Detailed examination with 16 monoclonal anti-H-2Ld antibodies revealed that the binding of some antibodies was significantly reduced in the glycosylation mutant, implying a certain contribution of the carbohydrates to the antigenic activity of some determinants. No detectable changes have been observed in the mutant of the substitution at position 116 by the parameters we tested.
Co-expression of an epitope on human free kappa-light chains and on a cytoplasmic component in activated T cells.
Authors: Walker K Z , Hayden G E , Goodnow C C , Boux H A , Adams E , Basten A , Raison R L 
Published: December 2022

Abstract
K-1-21 is a murine monoclonal antibody that reacts with human kappa-light chains in free form but not when they are associated with immunoglobulin heavy chains. K-1-21 was unexpectedly shown to bind to a determinant, STA (Sezary T cell antigen), detected by immunofluorescence in the cytoplasm but not on the surface of Sezary T cells isolated from peripheral blood (4/4 cases) and in Sezary T cells from lymph node and bone marrow (one patient). STA was detected in F2/F7, CCRF-CEM, Molt-4, and CCRF-HSB (four human T ALL cell lines), in JURKAT (a human T cell leukemia line), and in MLA144 (a Gibbon T cell lymphoma line). It also occurred in Leu-3a+ antigen-specific T cell clones (6/6 tested). Moreover, although STA was absent from freshly isolated normal T cells, its expression could be evoked in E+ cells from peripheral blood by in vitro culture with phytohemagglutinin. Thus, STA appears to be a cytoplasmic marker for activated T cells. Cytoplasmic inhibition immunofluorescence studies indicated that K-1-21 binding to STA in Sezary cells or T cell lines was inhibited by preincubation of the K-1-21 antibody with purified kappa-Bence Jones protein. STA from radiolabeled MLA144 cell lysates was immunoprecipitated by K-1-21 and was identified on polyacrylamide gel electrophoresis under reducing conditions as a protein of m.w. 57,000. Additional experiments are underway to define the molecular basis of the interesting cross-reactivity between a determinant in T cells and the K-1-21 reactive epitope on free kappa-light chains.
Epidermal cells as accessory cells in the generation of allo-reactive and hapten-specific cytotoxic T lymphocyte (CTL) responses.
Authors: Steiner G , Wolff K , Pehamberger H , Stingl G 
Published: December 2022

Abstract
The capacity of epidermal cells (EC) to stimulate T cell activation is a Langerhans cell (LC)-dependent phenomenon. In all in vitro assays probed, LC subserve antigen-presenting cell functions in that they display surface-bound foreign or altered-self structures and thereby activate T cell responses. In contrast, attempts to demonstrate accessory cell (ACC) function of LC-containing EC have yielded negative results, i.e., EC lacking foreign cell surface antigens were not able to restore cytotoxic T lymphocyte (CTL) responses in Ia+ adherent cell-depleted cultures. Reasoning that the ACC function of EC might be critically linked to cluster formation between LC and other cell types involved, we tested the ACC function of EC under experimental conditions that allow a close physical contact between the cell types involved (round-bottomed microtiter plates and brief centrifugation of culture plates). By using these modifications, the failure of highly purified B6 T cells to develop alloreactive CTL activity when stimulated with either highly purified, mitomycin C-treated C3H or B6CF1 T cells was restored by the addition of B6 EC. The CTL thus generated produced significant lysis of Con-A-stimulated C3H or BALB/c, but not B6, spleen cell targets. In a similar fashion, TNP- or FITC-specific CTL were generated when (in a syngeneic system) mitomycin C-treated TNP- or FITC-modified stimulator T cells and responder T cells were co-cultured in the presence, but not in the absence, of unmodified EC. The capacity of EC to restore CTL activity in a culture system depleted of Ia-bearing cells was not dependent upon their H-2 type, but was critically linked to the presence of Ia-bearing LC. We therefore conclude that LC-containing EC can subserve the ACC function in the generation of H-2-restricted CTL, provided that culture conditions are chosen that allow a close physical contact between the cell types involved.
Effect of priming with antigen on the expression of C3 receptors on murine B cells and the responses to TI-2 antigens.
Authors: Nariuchi H , Kakiuchi T , Ueno J 
Published: December 2022

Abstract
The effect of priming with DNP-Ficoll on the expression of receptors for the third component of complement (CR) on B cells was studied. B cells from mice primed with antigen were separated into CR- and CR+ populations by rosetting and density gradient centrifugation, and they were examined for antibody responses to TI-2 antigens in vitro. CR- B cells in spleen cells from mice primed with antigen responded well in contrast with the low responsiveness of CR- B cells from unprimed mice. These CR- B cells from primed mice reached their peak responses 1 day earlier than CR+ B cells from primed or unprimed mice. The response of these CR- B cells was specific for the hapten used for priming, and the priming effect was most conspicuous in spleen cells from mice primed with antigen 3 days previously, and it decreased thereafter. The CR- B cells from primed mice also showed better responses than CR+ B cells to all polyclonal B cell activators (PBA) tested. When CR+ B cells were primed in vitro with DNP-Ficoll for 3 days, the major cell population responsive to the antigen in secondary culture was found to be CR- B cells. On the other hand, CR- B cells in spleens could not respond to DNP-Ficoll challenge after in vitro priming with the antigen for 3 days. These results indicate that B cells lose CR by priming with antigen, although they retain their responsiveness to antigens and PBA. The role of CR on B cells in the antibody response is discussed.
Functional analysis of macrophage hybridomas. I. Production and initial characterization.
Authors: Uchida T , Ju S , Fay A , Liu Y , Dorf M E 
Published: December 2022

Abstract
A series of macrophage hybridomas were generated by fusion of splenic adherent cells with P388D1 tumor cells. Forty-two cell lines were established, and each was cloned by limiting dilution. Six clones that exemplified the spectrum of macrophage heterogeneity were selected for further analysis. Qualitative and quantitative differences in phenotype and functional activity were noted. Some clones constitutively expressed Ia antigens, whereas others only expressed detectable levels of Ia after lymphokine activation. The level of antigen-presenting activity generally correlated with the level of Ia expression. Furthermore, interclonal differences were noted in the levels of receptor-mediated phagocytosis and IL 1 secretion. Generally, the hybridoma clones maintained stable phenotypic and functional properties during approximately 1 yr of continuous in vitro culture. These cloned hybridoma cell lines represent a useful resource to analyze macrophage biology and to dissect structure and function relationships.
Enhanced response to Con A and production of TCGF by lymphocytes of obese strain (OS) chickens with spontaneous autoimmune thyroiditis.
Authors: Schauenstein K , Krömer G , Sundick R S , Wick G 
Published: December 2022

Abstract
The mitogenic response to Con A and the production of T cell growth factor or interleukin 2 (IL 2) by splenic and peripheral blood lymphocytes of obese strain (OS) chickens with spontaneous autoimmune thyroiditis have been investigated. By using an optimized method with Con A-coated chicken erythrocytes (MRC), lymphocytes of OS chickens were found to exhibit significantly elevated mitogenic responses as compared with cells from either Normal White Leghorn chickens (NWL) or animals of the Cornell C-Strain (CS), from which the OS has originally been developed. This difference was observed throughout ontogeny up to 15 mo of age, and was associated with increased levels of IL 2 activity in the culture supernatants. The elevated responsiveness of OS T lymphocytes was also found to be manifested in the expression of receptors for IL 2, because Con A-stimulated lymphocytes of OS birds were significantly more effective than those from normal controls in absorbing IL 2 activity from conditioned media (CM) of stimulated spleen cells. High concentrations of CM were suppressive in IL 2 assays, signaling the presence of an inhibitory factor(s) in addition to IL 2. An additional indication for defective immunoregulation was that CM from OS lymphocyte cultures showed significantly less of this suppressive activity in comparison with CM of normal (NWL and CS) lymphocyte cultures. Finally, the spontaneous uptake of 125IUdR of embryonic and early post hatching OS spleen lymphocytes was consistently and significantly enhanced. This difference, however, in contrast to the one observed in Con A responses, was found to decrease with age. The data are discussed in view of the contradictory results concerning T cell functions reported for several autoimmune states in mammals.
Reconstitution of in vivo cell-mediated lympholysis responses in aged mice with interleukin 2.
Authors: Thoman M L , Weigle W O 
Published: December 2022

Abstract
Advancing age is accompanied by declining immune potential. Both humoral and cellular immune responses are diminished in aged humans and experimental animals. A major lesion preventing effective T cell-mediated responses is the lack of interleukin 2 (IL 2) synthesis in aged mice. Addition of IL 2 can effectively reconstitute in vitro T cell-dependent humoral and cell-mediated immunity. These results have been extended, demonstrating that IL 2-containing lymphokine preparations when administered with antigen can restore the ability of aged mice to generate cytotoxic T lymphocytes in vivo. Furthermore, IL 2 has been identified as the active component of these lymphokine preparations through the use of purified human IL 2 prepared by recombinant DNA and gene cloning technology. The cloned IL 2 is highly effective in enhancing the immune responses of aged animals both in vitro and in vivo.
Comparative effects of various classes of mouse interferons on macrophage activation for tumor cell killing.
Authors: Pace J L , Russell S W , LeBlanc P A , Murasko D M 
Published: December 2022

Abstract
The effects of mouse interferon-alpha (MuIFN-alpha), -beta (MuIFN-beta), and -gamma (MuIFN-gamma) on macrophage activation for tumor cell killing were determined by using proteose peptone-elicited peritoneal macrophages from C3H/HeN and C3H/HeJ mice under conditions that either included or were free of detectable endotoxin. Alone, under the conditions used, none of the interferons was able to activate macrophages directly for tumor cell killing. However, with a second signal provided to responsive macrophages by contaminating endotoxin, added bacterial lipopolysaccharide (LPS), or heat-killed Listeria monocytogenes (HKLM), all three types of interferon induced cytolytic activity, with MuIFN-gamma approximately 500 to 1000-fold more active than either MuIFN-alpha or -beta. Thus, all three interferons were able to prime macrophages for killing but required a second signal before cytolytic activity could be expressed. When MuIFN-gamma was mixed with either MuIFN-alpha or -beta and placed on macrophages, little or no killing developed. Mixtures of MuIFN-gamma with either MuIFN-alpha or -beta did increase the sensitivity of macrophages to triggering by LPS, however, compared with macrophages treated with MuIFN-gamma alone. The results are collectively important because they i) confirm that significant quantitative differences exist between the various interferons with regard to their capacity to prime macrophages for tumor cell killing; ii) indicate that to be an efficient activator each type of interferon must be combined with a second stimulus, such as LPS or HKLM; iii) show that neither MuIFN-alpha nor -beta can provide an efficient second triggering signal for macrophages that are primed by MuIFN-gamma; and iv) document that mixtures of MuIFN-gamma with either MuIFN-alpha or -beta are most efficient at inducing priming, compared with any one of the interferons used alone.
Bone marrow-derived macrophages: development and regulation of differentiation markers by colony-stimulating factor and interferons.
Authors: Warren M K , Vogel S N 
Published: December 2022

Abstract
To investigate the role of specific cytokines in the development of the fully mature macrophage, we have employed murine bone marrow cells that were grown in the presence of CSF-1, a colony-stimulating factor that has been shown to induce the proliferation and differentiation of macrophages from their precursor cells. The CSF-1 employed in these studies was partially purified to ensure removal of contaminating interferon (IFN) from the preparations. After 1 to 2 wk in the presence of the partially purified CSF-1, the adherent macrophages were removed from flasks enzymatically and were recultured at known densities in the absence of CSF-1. Cell surface antigens (Mac-1 and Ia) and Fc receptor capacity (as assessed by Fc-mediated phagocytosis) were examined as markers of macrophage differentiation. Basal levels of Fc receptor capacity and Mac-1 antigen were markedly influenced by exposure to CSF-1, and appear to be modulated by CSF-induced, macrophage-derived IFN. When the bone marrow-derived macrophages were exposed to exogenous IFN in the absence of CSF-1, they proved to be extremely inducible with respect to Fc-mediated phagocytosis (IFN-beta and rIFN-gamma) and Ia antigen expression (rIFN-gamma) when compared with thioglycollate-elicited macrophages. Thus, macrophage growth factors, such as CSF-1, promote macrophage maturation by inducing the production of autostimulatory signals, such as macrophage-derived IFN. In addition, exogenous cytokine stimuli, such as IFN-gamma, further amplify the differentiative potential of these cells. Bone marrow-derived macrophages, propagated under well-defined conditions and never exposed to eliciting agents, provide a powerful model for studying the role of cytokines, such as CSF-1 and IFN, in the differentiative pathway of macrophages.
Activity of rheumatoid factors of different molecular sizes: comparison of autologous monomeric and polymeric monoclonal IgA rheumatoid factors.
Authors: Schrohenloher R E , Koopman W J , Moldoveanu Z , Solomon A 
Published: December 2022

Abstract
Differences in rheumatoid factor (RF) activity among the molecular species of IgA were investigated with the use of monomeric and polymeric monoclonal IgA RF paraprotein from the serum of a patient (PS) with idiopathic hyperviscosity syndrome. After fractionation by gel chromatography in acidic buffer, RF activity as determined by latex fixation and solid-phase radioimmunoassay (RIA) specific for IgA RF was confined to the high m.w. (greater than 7S) fractions. However, after adsorption into polystyrene wells, fractions containing monomeric (7S) IgA, as well as those containing polymeric IgA, bound 125I-labeled heat-aggregated human IgG. These observations were confirmed after further purification of the IgA fractions by passage through a protein A-Sepharose CL-4B column followed by precipitation of the IgA proteins with ammonium sulfate at 50% saturation. After "cross-linkage" by a hybridoma anti-human alpha-chain antibody, the activity of the monomeric IgA preparation in the IgA RF RIA approached that of the polymeric IgA preparation. Gel filtration studies verified that this activity was not due to contamination by polymeric IgA RF. Further, classic RF specificity was confirmed for both the monomeric and polymeric IgA RF by reaction with human Fc-coated but not Fab-coated wells. A control monomeric IgA myeloma protein and normal serum IgA did not react in the RF RIA when analyzed in the presence or absence of the hybridoma anti-alpha-chain antibody. Moreover, the activity of the polymeric IgA RF preparation from patient PS in the RIA was minimally influenced by the hybridoma antibody. These results indicate that IgA RF can coexist in both polymeric and monomeric forms, demonstrate that monomeric IgA RF may escape detection by previously described RIA techniques, and suggest an approach for its detection.
Cellular events during radiation-induced thymic leukemogenesis in mice: abnormal T cell differentiation in the thymus and defect of thymocyte precursors in the bone marrow after split-dose irradiation.
Authors: Muto M , Kubo E , Sado T 
Published: December 2022

Abstract
Cellular events during the development of thymic lymphomas in young B10.BR mice given leukemogenic split-dose irradiation were studied by examining the differentiation of functional T lymphocyte precursors in the regenerating thymus. It was found that leukemogenic radiation treatment resulted in a sustained depression of the level of thymic cytotoxic T lymphocyte precursors (CTLp) and of mixed lymphocyte reactivity of thymus cells when assessed between 1 and 4 mo after irradiation, in spite of the fact that the total number of thymocytes was restored to the normal level within 2 mo and continued to increase thereafter. In vitro mixing studies of normal thymocytes with thymus cells from split-dose irradiated mice provided no evidence for active suppression as a mechanism for this depressed activity. The ability of bone marrow cells from split-dose irradiated mice to regenerate the thymus and to differentiate into functional CTLp was examined by use of supralethally irradiated Thy-1 congenic recipients. Reconstitution of supralethally irradiated B10.BR Thy-1.2 mice with normal bone marrow from B10.BR Thy-1.1 mice resulted in the complete repopulation of host-thymus with donor-derived cells when assessed at 4 wk after reconstitution. Lymphocytes from the regenerating thymus of these animals were shown to contain high levels of CTLp which were donor-derived. On the other hand, when the recipient mice were reconstituted with bone marrow cells from donor mice which had been split-dose irradiated 1 mo earlier, regeneration of the recipient thymus was severely depressed when assessed at 4 wk to 3 mo after reconstitution. Although variable but small numbers of donor-derived Thy-1+ cells were detected, CTL activity for alloantigen could not be induced in these donor-derived cells. The results suggest that T cell precursors derived from split-dose irradiated donor mice were unable to undergo active proliferation and differentiation into functional CTLp. The significance of these findings on radiation-induced thymic leukemogenesis is discussed.
H-2-restricted helper activity mediated by immunoglobulin-bearing lymphocytes.
Authors: Sherr D H , Dorf M E 
Published: December 2022

Abstract
The genetic requirements for helper activity mediated by a unique, Ig-bearing lymphocyte population were studied. This Lyt-1+, I-A+, Thy-1- population, called BH, preferentially helps expression of NPb idiotypic plaque-forming cells when added to T cell-depleted responder cultures. Furthermore, the BH population can directly bind NPb idiotypic determinants. Using H-2 congenic mice, we show that BH helper activity can be expressed only when BH cells share I-A subregion alleles with responder B cell populations. This H-2 restriction is not a result of thymic influences, because the activity of BH cells from athymic mice are also H-2 restricted. Macrophages present in the BH population do not contribute to the H-2 restriction. Results are presented that definitively rule out the possible role for T lymphocytes in BH activity and demonstrate that a single helper population expresses both Lyt-1 and I-A determinants. These results indicate that Ig-bearing cells serve a regulatory as well as an effector role in immune responses and that, like other regulatory lymphoid subsets, their activity is regulated in part by MHC-encoded determinants.
The role of T8 in the cytotoxic activity of cloned cytotoxic T lymphocyte lines specific for class II and class I major histocompatibility complex antigens.
Authors: Spits H , Yssel H , Voordouw A , de Vries J E 
Published: December 2022

Abstract
It is reported here that most cytotoxic T lymphocytes (CTL), which recognize class I major histocompatibility complex (MHC) loci, express the T cell differentiation antigen T8. However, a minority of T8+ CTL clones was found to recognize class II MHC antigens. To test the hypothesis that T8 is involved only in T cell recognition of class I MHC antigens, we studied the role of T8 in the cytotoxic activity of class II MHC-specific CTL. Monoclonal antibodies specific for T8 blocked the activity of most class I MHC-specific CTL clones but did not affect the activity of class II MHC-specific CTL clones. Moreover, a mild trypsin treatment of the clones, which removed and T8 determinant, affected the activity of class I MHC but not that of class II MHC-specific CTL clones. These findings indicate that the class II-specific MHC CTL clones described here did not require T8 for their cytolytic activity. The activity of one T8+ class I MHC-specific (HLA-B27) CTL clone (HG-61) against the B cell line JY, which was used to raise this CTL clone, was not blocked by trypsin treatment of this clone. However, the activity of CTL clone HG-61 against target cells different from JY but carrying the appropriate HLA specificity was blocked by anti-T8 antibodies and trypsin treatment. The implications of these findings for the hypothesis that T8 is involved only in the activity of CTL with a relatively low avidity for class I MHC antigens are discussed.