bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential activation of CD8+ T cells by transforming growth factor-beta 1.
Authors: Lee H M , Rich S 
Published: January 2023

Abstract
Transforming growth factor-beta (TGF-beta) is a highly conserved multifunctional factor that broadly regulates cell growth and differentiation, and exhibits diverse regulatory roles in the immune system. In contrast to other studies describing TGF-beta as a potent inhibitor of lymphocyte growth, we have shown previously that TGF-beta 1 can also costimulate proliferation of murine splenic T cells activated by immobilized anti-CD3 antibody. In the present studies, we further investigate the subsets of T cells that are responsive to TGF-beta 1 costimulation. T cells were isolated into CD45RBhi/lo or CD4+/8+ populations, and their responses to TGF-beta 1 were examined. Sorted CD45RBhi cells were highly responsive to TGF-beta 1 costimulation, and proliferated to a level similar to that of unsorted T cells in response to TGF-beta 1. TGF-beta 1 also costimulated proliferation in the CD45RBlo population that was distinguished by low response and delayed kinetics. In contrast, sorted CD4+ and CD8+ T cells showed a striking differential response. Anti-CD3-stimulated proliferation of sorted CD8+ or CD4- T cells was substantially enhanced by TGF-beta 1, whereas sorted CD4+ or CD8- T cells were unresponsive. TGF-beta 1 also down-regulated CD45RB and increased CD44 expression on responsive CD8+ and CD45RBhi T cells, thereby leading to a population of T cells enriched in mature phenotype. Generation of anti-CD3-redirected lytic activity by these TGF-beta 1-costimulated CD8+ cells was strongly suppressed. However, these CD8+ T cells exhibited cytotoxic activity after restimulation in the absence of TGF-beta. TGF-beta 1 precultured CD8+ T cells also had heightened IL-2 and IFN-gamma secretion upon restimulation in comparison to cells activated initially without TGF-beta. CD8+ T cells precultured with anti-CD3 and TGF-beta remained responsive to growth enhancement by TGF-beta, although re-exposure to TGF-beta depressed other functions of these cells. Thus, TGF-beta 1 demonstrates important costimulatory roles in both growth and maturation of CD8+ T cells.
Structural complexity of antigenic determinants for class I MHC-restricted, hapten-specific T cells. Two qualitatively differing types of H-2Kb-restricted TNP epitopes.
Authors: Martin S , von Bonin A , Fessler C , Pflugfelder U , Weltzien H U 
Published: January 2023

Abstract
The understanding of chemically induced allergic or autoimmune disorders requires a detailed structural analysis of the antigenic determinants produced by chemical modification of cells. Using H-2Kb-restricted, TNP-specific cytotoxic mouse T cells and synthetic, Kb-associating TNP-peptides, we define at least two types of functionally distinguishable TNP epitopes. The first one contains TNP in position 4 of different Kb-binding octapeptides and is detected by the majority of in vitro-induced TNP/Kb-specific CTL. This immunodominant structure could be imitated by oligo-glycine based "designer peptides," containing only the Kb "anchor-residues" and TNP-Lys in position 4. A second, qualitatively different determinant is created by TNP-Lys in position 7. T cells of such specificity are rare and recognize TNP only in context of unique peptide sequences. In this case, designer peptides revealed a complex antigenic determinant comprised of TNP-7 and unmodified amino acids in positions 3 and 4. Chances to form a particular determinant of this type by chemical modification are small and, thus, each clone will detect only few epitopes per cell. In contrast, the dominant TNP-4 epitope on differing peptides results in highly repetitive determinants. TCR specific for the rare TNP-7 structure were found to simultaneously contact TNP in position 7 and unmodified amino acids in positions 3 and 4. However, they may also react individually with either the peptide or the hapten part of these complex determinants. This implies a potentially important role of such structures in the induction of autoimmunities: resting T cells, bearing low affinity receptors to self peptides may be activated by peptide/hapten complexes and allow recall responses to the isolated peptide epitope of the unmodified self peptide.
Molecular cloning of a novel human hsp70 from a B cell line and its assignment to chromosome 5.
Authors: Fathallah D M , Cherif D , Dellagi K , Arnaout M A 
Published: January 2023

Abstract
A 2391-bp cDNA encoding a novel human hsp70, named hsp70 RY, is described. It was cloned from a cDNA library constructed using mRNA derived from an established EBV-transformed B cell line from a patient with leukocyte adhesion molecule deficiency. hsp70 RY is 701 amino acids long, has the characteristic N-terminal ATP-binding domain and the C-terminal peptide binding domain, and contains four potential N-glycosylation sites. Northern blotting revealed a single mRNA species of 3.0 kb in total RNA prepared from the patient's EBV cell line. In situ hybridization localized the single copy hsp70 RY gene to the long arm of chromosome 5 at 5 q31.1-5 q31.2.
Assembly of the T-cell antigen receptor. Participation of the CD3 omega chain.
Authors: Neisig A , Vangsted A , Zeuthen J , Geisler C 
Published: January 2023

Abstract
The human TCR is composed of the Ti alpha beta heterodimer in association with the CD3 chains CD3 gamma delta epsilon zeta 2. Another chain, referred to as CD3 omega, has recently been described in T cells. CD3 omega is an intracellular protein transiently associated with the CD3 complex during the assembly of the TCR in the endoplasmic reticulum (ER) and it is not expressed on the cell surface. The function of CD3 omega is unknown but it has been suggested that it plays an important role in the assembly of the TCR. We have studied the possible function of CD3 omega in the human leukemic T-cell line Jurkat and different variants of this cell line. Cells were metabolically labeled, subjected to lysis, immunoprecipitated, and analyzed by SDS-PAGE. The results indicate that: 1) CD3 omega associates primarily with the CD3 delta epsilon complex; 2) CD3 omega is not associated with single Ti alpha or Ti beta chains, but is present in complexes composed of both the CD3 and the Ti chains; 3) CD3 omega is part of the complete, intracellular receptor complex Ti alpha beta/CD3 gamma epsilon delta omega zeta 2; and 4) CD3 omega dissociates from the Ti/CD3 complex in the ER before maturation of the Ti alpha beta heterodimer. On the basis of these results, we propose a model for the assembly and subunit stoichiometry of the TCR complex which includes the participation of the CD3 omega chain.
Induction of CREB activity via the surface Ig receptor of B cells.
Authors: Xie H , Chiles T C , Rothstein T L 
Published: January 2023

Abstract
The regulation and function of CREB was examined in B cells to begin to elucidate the role of cAMP-derived signals in B cell activation. CRE-binding activity detected by the electrophoretic mobility shift assay was found to be constitutively expressed in nuclear extracts of primary murine splenic B cells and was unchanged in nuclear extracts obtained from B cells stimulated in a variety of ways. This activity was shown to be specific by competition analysis and to represent CREB or a closely related molecule on the basis of a "supershift" in the mobility of the nucleoprotein complex induced by anti-CREB antiserum. The function of B cell CREB was assessed by transient transfection of the murine B lymphoma cell line, BAL-17, with a CRE-dependent chloramphenicol acetyl-transferase (CAT) construct that contains a portion of the somatostatin promoter. Cross-linking of the surface Ig receptors of transfected BAL-17 B cells produced a threefold induction of CAT activity. Forskolin, which markedly induced CAT expression in PC12 cells transfected with the CRE-dependent construct, failed to stimulate CAT activity in transfected BAL-17 B cells despite an increase in cAMP. However, anti-Ig was found to act in synergy with forskolin to produce enhanced CAT activity. A phosphoprotein of appropriate molecular size for CREB was immunoprecipitated from anti-Ig plus forskolin treated BAL-17 B cells. These results suggest that CREB is present in primary B cells and that CRE-dependent gene expression is regulated by surface Ig either alone or in synergy with cAMP; the latter implies cross-talk between intracellular signaling pathways acting at the level of CREB.
Transforming growth factor-beta primes macrophages to express inflammatory gene products in response to particulate stimuli by an autocrine/paracrine mechanism.
Authors: Noble P W , Henson P M , Lucas C , Mora-Worms M , Carré P C , Riches D W 
Published: January 2023

Abstract
Macrophages maintain an essential role in orchestrating the host inflammatory response by selectively mobilizing portions of their large secretory repertoire in response to phagocytic as well as other stimuli. For example, after exposure to the inflammatory particulate stimulus zymosan (or its derivative beta 1,3-glucan), monocyte/macrophages synthesize and release lysosomal hydrolases, mobilize arachadonic acid, and secrete cytokines such as TNF-alpha and IL-8. However, the mechanisms by which particulate stimuli promote the selective synthesis and release of macrophage-derived inflammatory gene products are unknown. Given the previously reported potential of transforming growth factor-beta (TGF-beta) as an important mediator of the inflammatory response in vivo, we investigated the role of TGF-beta in the regulation of particulate-induced macrophage inflammatory gene expression. We determined that TGF-beta primed macrophages to synthesize lysosomal hydrolases and express platelet-derived growth factor-B mRNA transcripts in response to both submaximal doses of beta 1,3-glucan and the nonspecific phagocytic stimulus latex particles, which by themselves did not induce expression of either inflammatory gene product. The endogenous production of active TGF-beta was shown to regulate inflammatory gene expression by demonstrating that: 1) beta 1,3-glucan stimulated both TGF-beta mRNA expression and protein release into conditioned media; 2) supernatants from stimulated macrophages primed for lysosomal hydrolase synthesis, and this effect was blocked by anti-TGF-beta antibodies; and 3) anti-TGF-antibodies blocked beta 1,3-glucan-stimulated lysosomal hydrolase synthesis. Collectively, these data describe a novel function for TGF-beta as a priming agent for macrophage inflammatory gene expression and suggest a mechanism for local amplification of the inflammatory response.
Human cytomegalovirus down-regulates HLA class I expression by reducing the stability of class I H chains.
Authors: Beersma M F , Bijlmakers M J , Ploegh H L 
Published: January 2023

Abstract
Human CMV (HCMV) infection leads to an almost complete inhibition of expression of MHC class I proteins. After infection with HCMV, the biosynthesis of HLA class I molecules was examined in human lung fibroblasts and in mouse fibroblasts transfected with genes encoding the human class I H chain HLA-B27 and human beta 2-microglobulin (beta 2m). In both cell types, we observed a large decrease in steady state levels specific for human class I H chains--both free H chains and those complexed with beta 2m. In the mouse cells transfected with HLA class I, infection did not affect levels and assembly of mouse class I H chains with human beta 2m. The effect of HCMV infection on class I expression is insensitive to phosphonoacetic acid, suggesting the involvement of immediate early or early viral proteins. Pulse-chase analysis showed that the low steady state level of class I H chains in HCMV-infected cells is not the result of a reduced rate of synthesis. Rather, we observed accelerated degradation of class I H chains, regardless of their association with beta 2m. We conclude that HCMV reduces human MHC class I protein levels by interference with the stability of class I H chains.
Most gamma delta T cells develop normally in the absence of MHC class II molecules.
Authors: Bigby M , Markowitz J S , Bleicher P A , Grusby M J , Simha S , Siebrecht M , Wagner M , Nagler-Anderson C , Glimcher L H 
Published: January 2023

Abstract
MHC class I and class II molecules are essential for intrathymic maturation of a normal repertoire of alpha beta T cells. The development of gamma delta T cells may similarly require exposure to conventional MHC or MHC-like molecules for appropriate negative and positive selection. The availability of mice that are devoid of cell surface expression of MHC class II molecules allowed us to test directly the hypothesis that conventional class II molecules play a role in the development of gamma delta T cells. The proportions of gamma delta cells in thymus, lymph nodes, and spleens were indistinguishable between class II-deficient mice and littermate controls by FACS analysis. gamma delta T cells from class II-deficient mice proliferated normally in response to anti-TCR mAb. Examination of epidermal sheets from ear, torso, and tail skin demonstrated that class II-deficient mice had the same population density and distribution of gamma delta+ dendritic epidermal T cells as that of control littermates. gamma delta Cells in the epidermis of class II-deficient mice expressed Thy-1 and CD3 and were predominantly V gamma 3+. There were no significant differences in the immunophenotype of class II-deficient mice and their normal littermates in two-color immunofluorescence analysis of intestinal intraepithelial lymphocytes. Class II-deficient mice and control mice had 29 to 39% gamma delta bearing intestinal intraepithelial lymphocytes, of which 16 to 21% expressed V delta 4. Dendritic cells that stained positively for Thy-1, CD3, and gamma delta were identified in the vaginal epithelium of class II-deficient mice and their normal littermates. Our results indicate that MHC class II expression is not essential for the development of most gamma delta T cells.
T cells within germinal centers are specific for the immunizing antigen.
Authors: Fuller K A , Kanagawa O , Nahm M H 
Published: January 2023

Abstract
A normal antibody response to T cell-dependent Ag requires physical contact between Ag-specific B and T cells. Because such Ag-specific cells are rare in vivo, we sought to identify an in vivo site where they physically contact each other. We examined the Ag specificity of T cells in germinal centers (GC) in lymph nodes, where it is known that Ag-specific B cells proliferate and mature. We investigated the Ag specificity of GC T cells in situ by examining two characteristics: 1) expression of certain V alpha and V beta TCR families; and 2) incorporation of bromodeoxyuridine into T cell DNA after exposure to Ag as an index of Ag-induced proliferation. When GC were induced in mice with cytochrome c and myelin basic protein, the GC T cells were found to preferentially express V alpha 11 and V beta 8 TCR families, which are, respectively, the dominant TCR families in these two responses. Furthermore, GC T cells have proliferated upon exposure to the Ag that induced GC formation. Taken together, these results demonstrate that GC must recruit and retain Ag-specific T cells, thus implicating the GC as an in vivo site where Ag-specific T and B cells interact.
Evidence that murine V gamma 5 and V gamma 6 gamma delta-TCR+ lymphocytes are derived from a common distinct lineage.
Authors: Heyborne K , Fu Y X , Kalataradi H , Reardon C , Roark C , Eyster C , Vollmer M , Born W , O'Brien R 
Published: January 2023

Abstract
Murine V gamma 5 and V gamma 6+ T lymphocytes develop sequentially in the thymus during fetal and newborn life, giving rise to intraepithelial lymphocytes of the epidermis and female reproductive tract. In analyzing a panel of gamma delta T cell hybridomas derived from various tissues, we found that all V gamma 6+ cells tested (n = 25) expressed V gamma 5-C gamma 1 mRNA, whereas none of a panel of V gamma 6- cells analyzed (n = 33) expressed this mRNA. V gamma 6 mRNA was rare in V gamma 5+ cells (1 of 9), and absent in all other gamma delta T cells (n = 10). These findings suggest that most, if not all, V gamma 6-TCR+ lymphocytes arise from precursor cells that have previously rearranged the V gamma 5 gene, and indicate that V gamma 5 and V gamma 6+ lymphocytes belong to a common, distinct lineage that does not give rise to other gamma delta T cells.
Sequential switching from mu to epsilon via gamma 4 in human B cells stimulated with IL-4 and hydrocortisone.
Authors: Jabara H H , Loh R , Ramesh N , Vercelli D , Geha R S 
Published: January 2023

Abstract
The molecular events leading to IgE synthesis in human B cells stimulated with IL-4 and hydrocortisone were analyzed. IL-4, but not hydrocortisone, induced C epsilon germ line transcription. However, hydrocortisone increased the levels of IL-4-induced germ line C epsilon transcripts by twofold and delivered the signal required for transcription of mature C epsilon mRNA. Nested primer polymerase chain reaction of high m.w. DNA revealed deletional switch recombination occurring in B cells sorted for lack of expression of surface IgE and stimulated with both IL-4 and hydrocortisone, but not in B cells stimulated with IL-4 alone or hydrocortisone alone. DNA sequence analysis of 10 switch fragments revealed direct joining of S mu to S epsilon in eight fragments, one of which exhibited an 876-bp deletion in S mu. The ninth fragment contained a 50-bp insertion at the S mu/S epsilon junction, which was likely to be derived from S gamma 4. The sequence of the 10th fragment was consistent with either a 17-bp insertion at the S mu/S epsilon junction derived from S gamma 4 or with a complex 38-bp deletion within S epsilon. Mapping of the switch junction sites showed "hot spots" for recombination within S mu but not within S epsilon. These findings indicate that hydrocortisone induces S mu-S epsilon deletional switch recombination in IL-4-treated B cells, and support a model of sequential isotype switching from IgM to IgE via IgG4.
Synthesis of T helper 2-type cytokines at the maternal-fetal interface.
Authors: Lin H , Mosmann T R , Guilbert L , Tuntipopipat S , Wegmann T G 
Published: January 2023

Abstract
Clinical and experimental evidence has indicated that the maternal immune response is biased toward antibody production and away from cell-mediated immunity during pregnancy, especially in the vicinity of the fetoplacental unit. Because antibody responses are often associated with the Th2 cytokine pattern, this suggests that Th2-type cytokines might predominate locally in the regulation of the maternal immune response. In order to test this hypothesis, we examined the local and distal release of cytokines during murine pregnancy using ELISA assays. We report here that the Th2-specific cytokines IL-4, IL-5, and IL-10 were readily detectable in cell supernatants derived from fetal-placental units in all three trimesters of gestation. IL-3 was also present. These cytokines were detected in lysates of freshly isolated, day 12 decidual and placental cells, and in supernatants as early as 15 min after the beginning of culture. The presence of functional IL-10 was confirmed by specific bioassay. IL-10 mRNA was localized to the decidua at day 6 of gestation by in situ hybridization. IFN-gamma was also found in the supernatants from the first trimester of pregnancy, but was barely detectable in the second, and undetectable in the third trimester. Cytokine expression was consistently detected in samples from individual mice. None of these cytokines was produced by unstimulated spleen or mesenteric lymph nodes from pregnant mice. IL-4, IL-10, and IFN-gamma were produced by Con A-stimulated spleen cells from virgin mice, but in ratios opposite to those found in the placenta. These observations indicate that Th2-specific cytokines are normally produced at the maternal-fetal interface. The continuous presence of IL-4, IL-5, and IL-10, with early and transient expression of IFN-gamma, can provide a molecular basis for the antibody/Th2-like bias of the maternal immune response during pregnancy.
Antigen presentation by B lymphoma cells. Requirements for processing of exogenous antigen internalized through transferrin receptors.
Authors: McCoy K L , Gainey D , Inman J K , Stutzman R 
Published: January 2023

Abstract
The Ag, pigeon cytochrome c, was delivered to the early endosomes in a form coupled to human ferric transferrin that entered APC through transferrin receptors. The processing of the transferrin-Ag conjugate by B lymphoma cells was compared with that of unconjugated native Ag that entered APC by a nonreceptor-mediated mechanism. Within 5 min after internalization, catabolized conjugate was detected in isolated early endosomes and did not accumulate in these organelles. Analysis of the rapid catabolism of the conjugate demonstrated that the Ag, not the transferrin, portion of the molecule was degraded by the APC, suggesting that similar proteases may mediate the processing of the conjugate and native Ag. The processing mechanisms of these molecules shared similarities. Treatment of APC with chloroquine or paraformaldehyde interfered with the stimulation of Ag-specific CD4+ T cells by both transferrin-Ag conjugate and native Ag. However, the T cell responses to the conjugate and native Ag were different in two important respects. First, T cell activation by the conjugate began at an earlier time point and occurred at a faster rate than T cell stimulation by the same concentration of native Ag during a 3-h time course. Second, the T cell response to the conjugate, but not to native Ag, was diminished by treating APC with cycloheximide, a reversible protein synthesis inhibitor. This partial inhibition of the conjugate response by cycloheximide could not be attributed to significant effects on transferrin receptor expression, or on internalization, recycling, or degradation of the conjugate. The differential cycloheximide-sensitivity of the T cell responses indicates that the processing pathways of the two molecules are different. Our findings suggest that the early endosomes may function as an Ag-processing compartment, and that more than one pathway may lead to productive processing in B lymphoma cells.
The functional basis of minor histocompatibility loci.
Authors: Roopenian D C , Davis A P , Christianson G J , Mobraaten L E 
Published: January 2023

Abstract
This work addresses the functional basis of classical minor histocompatibility (H) loci. We focus on the H-3 locus, which is actually a complex genetic unit to which the phenotypic trait of tissue rejection, genes whose products stimulate specific subsets of T cells, and Ir genes have been mapped. To clarify how these genes relate to one another and to the trait of tissue rejection, strains of intra-H-3 recombinant mice were produced and analyzed. These mice allowed us to selectively elicit immune responses to Ag (referred to as type I Ag) that stimulate MHC class I-restricted CTL, or Ag (referred to as type II Ag) that stimulate MHC class II-restricted Th. The splitting of H-3 in this manner resulted in a dramatic diminution of the skin allograft response, and with rare exception, an elimination of the CTL response after spleen cell immunization. A selective response to type I Ag resulted in slow, incomplete skin allograft rejection that demonstrated both CD4+ cell-dependent and -independent components. A selective response to the type II Ag failed to result in allograft rejection. The type II Ag did, however, act as an Ir gene that determined whether responses to type I Ag could occur. Altogether, the results indicate that the trait of tissue rejection associated with H-3 is a consequence of the strongly synergistic effects of Th-CTL collaboration induced by products of type I and type II genes. Moreover, the results suggest a genetic explanation for some of the Ir gene effects associated with H-3.