bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiac xenografts between primate species provide evidence for the importance of the alpha-galactosyl determinant in hyperacute rejection.
Authors: Collins B H , Cotterell A H , McCurry K R , Alvarado C G , Magee J C , Parker W , Platt J L 
Published: December 2022

Abstract
Transplants performed between phylogenetically disparate species are subject to hyperacute rejection initiated by binding of xenoreactive natural Abs to endothelium in the donor organ. Binding of these Abs activates complement, leading to tissue injury and destruction of the graft. Human xenoreactive natural Abs recognize Gal alpha 1-3Gal beta 1-4GlcNAc (galactose alpha 1-3galactose beta 1-4-N-acetylglucosame); however, the relative importance of this Ag in graft rejection has not been proved. The present study was conducted to test the potential importance of alpha-galactosyl (alpha-Gal) determinants in the pathogenesis of hyperacute rejection. To this end, hearts (n = 3) from New World monkeys (Saimiri scureus, squirrel monkey), which can synthesize Gal alpha 1-3Gal, were transplanted heterotopically into Old World monkeys (Papio species, baboon), which do not synthesize Gal alpha 1-3Gal determinants and which have circulating anti-alpha Gal Abs. The xenografts were rejected in 51 to 56 min (mean +/- SD = 53.3 +/- 2.5), results similar to those observed in porcine grafts transplanted into baboons. Histologic analysis of the hearts revealed thrombosis and intraparenchymal hemorrhage and immune deposits consisting of IgM, Clq, C3, C4, C5b, and the membrane attack complex, but not properdin or factor B of the recipient deposited on graft endothelium. Sera obtained from baboons after perfusion of squirrel monkey kidneys revealed depletion of alpha-Gal-specific Abs and anti-pig endothelial cell Abs. These findings provide strong evidence that the Abs that accumulate in New World monkey organs during perfusion with baboon blood are the same Abs that would accumulate in a porcine organ transplanted into a primate and suggest that hyperacute rejection is not necessarily a reflection of phylogenetic distance but that the expression of terminal alpha-Gal residues provides an adequate target to initiate that process.
Simian immunodeficiency virus (SIV)-specific CTL in cerebrospinal fluid and brains of SIV-infected rhesus macaques.
Authors: von Herrath M , Oldstone M B , Fox H S 
Published: December 2022

Abstract
Simian immunodeficiency virus (SIV)-specific CD8+ CTL were isolated from blood, cerebrospinal fluid, and brains of rhesus macaques infected i.v. with SIV. CTL were found as early as 1 wk postinfection and their appearance correlated with a decrease of viral Ag (p27) found in the blood. CTL isolated from cerebrospinal fluid and/or brain often recognized different viral proteins than CTL isolated from blood, suggesting either a unique migratory pattern to the central nervous system or a difference in activation/retention of lymphocytes in these compartments.
Requirement of CTLA-4 counter receptors for IL-4 but not IL-10 elevations during a primary systemic in vivo immune response.
Authors: Lu P , Zhou X D , Chen S J , Moorman M , Schoneveld A , Morris S , Finkelman F D , Linsley P , Claassen E , Gause W C 
Published: December 2022

Abstract
The CD28/CTLA-4 costimulatory signal is required for TCR-mediated T cell activation resulting in increased IL-2 production in vitro, but its role in IL-4 production is unclear and few studies have examined the function of CTLA-4/CD28 in the in vivo immune response. We have examined the in vivo effects of blocking the interaction of B7 with its ligands, CTLA-4 and CD28, in an IL-4 dominant in vivo immune response to goat anti-mouse IgD. This response is characterized by elevations in serum Igs preceded by elevations in IL-2 and the Th2 cytokines: IL-4, IL-9, and IL-10. The fusion protein CTLA4-Ig administered during the in vivo immune response to goat anti-mouse IgD caused an inhibition in elevations of IL-2, IL-4, and IL-9 gene expression at both day 3 and day 6 after immunization. In contrast, IL-10 cytokine gene expression as late as day 6 after immunization was not decreased. Cell sorting analysis demonstrated that TCR-alpha beta +, CD4+ T cells were the primary source of the elevated IL-10, suggesting that T cell activation leading to IL-10 gene expression may not require CTLA-4 ligand interactions. Similarly CTLA4-Ig completely blocked elevations in the number of IL-4- but not IL-10-secreting cells, as measured by ELISPOT, in both unsorted splenic cells and sorted CD4+, TCR-alpha beta+ T cells. In situ staining of spleen sections also showed inhibition of IL-4-producing cells. These results suggest that, with the notable exception of IL-10, interaction, of B7 with its ligands is required for elevated Th2 cytokine gene expression and secretion during a primary systemic IL-4-dominant response.
Memory B lymphocytes in human tonsil do not express surface IgD.
Authors: Nicholson I C , Brisco M J , Zola H 
Published: December 2022

Abstract
To clarify the phenotype of memory B lymphocytes, we have determined the frequency of somatic hypermutations in purified tonsil B cell populations. Our particular interest was the controversial question of whether any memory B-cells express IgD. Ig heavy chain gene rearrangements that used the nonpolymorphic VH6 gene were amplified by PCR, cloned, and sequenced. All eight sequences obtained from the surface IgD (sIgD)-negative fraction contained point mutations, with frequency of one mutation in every 24 bases of sequence. In contrast, only 4 of 12 sequences obtained from the sIgD-positive fraction contained point mutations, with a mutation frequency of one in 600. This frequency was similar to that found for cord blood B cells (one in 550), a population that does not contain memory B cells. These results indicate that although memory B cells are present in the sIgD-negative fraction, no memory cells can be detected in the sIgD-positive fraction of tonsil B lymphocytes.
Induction of murine gamma delta T cells cytotoxic for xenogeneic rat cells.
Authors: Okumura C , Suto R , Furukawa K , Ahmed S S , Furukawa K , Nakayama E , Fujii T , Shiku H 
Published: December 2022

Abstract
C57BL/6 mice deprived or nondeprived of CD4+ and CD8+ T cells by mAbs were challenged with a rat T cell line, W7TM-1. Spleen cells obtained from CD4- and CD8-depleted animals rejecting W7TM-1 were examined by cytofluorometry, which demonstrated the presence of highly increased gamma delta type CD4-CD8- T cell population (30 to 50% of entire T cells). In vitro sensitization of these spleen cells with W7TM-1 generated a mixture of gamma delta and alpha beta type CD4-CD8- CTL for W7TM-1. Repeated stimulation of these cells with W7TM-1 resulted in a gamma delta-type T cell population with more than 95% purity by day 45. In contrast, alpha beta type CD8+ CTL for W7TM-1 were induced from mice nondeprived of CD4+ and CD8+ T cells. Both gamma delta-type CD4-CD8- CTL and alpha beta type CD8+ CTL were cytotoxic for rat cells in a species-specific manner. However, only reactivity of gamma delta type CD4-CD8- CTL, but not alpha beta type CTL, was inhibited by a mAb for TCR-gamma delta. The gamma delta type CD4-CD8- CTL clones were also prepared from spleen cells derived from CD4- and CD8-depleted mice. They were also reactive for xenogeneic cells in a species-specific manner. Spleen cells derived from CD4- and CD8-depleted mice rejecting the whole-layer rat skin grafts were in vitro sensitized with rat spleen cells, which also generated gamma delta type CD4-CD8- CTL specific for rat cells. V gamma 1 was detected as a major V gamma gene expressed in this gamma delta population by reverse transcriptase-PCR. Cytotoxicity for xenogeneic cells may represent one of major function of gamma delta T cells.
Expression of vitronectin receptor on human NK cells and its role in protein phosphorylation, cytokine production, and cell proliferation.
Authors: Rabinowich H , Lin W C , Amoscato A , Herberman R B , Whiteside T L 
Published: December 2022

Abstract
In this paper, we provide evidence that the vitronectin receptor (VNR) alpha v beta 3 is expressed on human NK cells. The presence of this VNR on freshly purified NK cells was demonstrated by flow cytometry analysis, as well as biochemically, after 125I-labeled surface lactoperoxidase labeling and immunoprecipitation. mAbs LM142 and LM609 specific for alpha v and alpha v beta 3, respectively, precipitated a heterodimer of alpha- and beta-chains with approximate molecular masses of 155 and 110 kDa under nonreducing conditions. Under reducing conditions, there was an apparent decrease in the molecular mass of the alpha-chain, which is likely to result from the release of a protein of 20 to 30 kDa linked by internal disulfide bond to the alpha v-chain. Integrin alpha v beta 3 expressed on NK cells became functional, i.e., was able to bind its ligand, vitronectin (VN), only after cellular activation or when costimulation with an additional signal was provided. Thus, NK cells adhered to plastic-immobilized VN only after IL-2 activation, and RGD-containing synthetic peptides or mAbs specific for alpha v beta 3 complex inhibited this binding. To assess the role of the VNR in signal transduction, anti-beta 3 mAb was used to cluster the VNR on NK cells and, thereby, mimic the process that occurs during formation of adhesive contacts. Cross-linking of VNR on fresh NK cells stimulated phosphorylation on tyrosine residues of several intracellular proteins. The major increase in tyrosine phosphorylation was observed in proteins of approximate molecular masses of 75 and 120 kDa. Therefore, signal transduction by the VNR on NK cells induced activation of intracellular protein kinases. Ligand engagement of the VNR on NK cells also costimulated cytokine production and proliferation of NK cells. Binding of NK cells to plastic-immobilized VN served as a costimulus with either anti-Fc gamma RIII or IL-2 to produce IFN-gamma, TNF-alpha, and cell proliferation. Our findings suggest that occupancy and subsequent clustering of VNRs play a role in the activation and function of human NK cells.
Comitogenic effects of very late activation antigens on CD3-stimulated human thymocytes. Involvement of various tyrosine kinase pathways.
Authors: Ticchioni M , Deckert M , Bernard G , Calandra D , Breittmeyer J P , Imbert V , Peyron J F , Bernard A 
Published: December 2022

Abstract
Thymocytes display several integrins that are involved in cell-extracellular matrix interactions and differentiation processes. We have examined the role of very late activation Ag (VLA) on human thymocyte stimulation. VLA-4, VLA-5, and VLA-6 activated with either mAbs or their natural ligands (fibronectin, laminin, and vascular cell adhesion molecule-1) are able to transduce costimulatory signals in thymocytes activated via the CD3 pathway, i.e., enhancement of thymocyte proliferation, CD25 and CD69 expression, and IL-2 secretion. In contrast, activation of thymocytes with a mitogenic pair of CD2 mAb was not modified by VLA molecules. Cross-linking of both beta 1- and alpha 5-chains induced tyrosine phosphorylation of several proteins, whereas the cross-linking of the alpha 4- and alpha 6-chains did not. Moreover, a different pattern of tyrosine phosphorylation was observed when thymocytes were activated via either beta 1- or alpha 5-chains. These results suggest that VLA molecules activate tyrosine kinase pathways in thymocytes, and that different pathways would be implicated during thymocyte interactions with extracellular matrix or accessory cells, which are likely to play a role in thymocyte differentiation.
Characterization of human Fas gene. Exon/intron organization and promoter region.
Authors: Cheng J , Liu C , Koopman W J , Mountz J D 
Published: December 2022

Abstract
Ligation of the Fas cell-surface molecule induces apoptosis. Defective Fas-mediated apoptosis has been associated with spontaneous autoimmunity in mice. Using human Fas/Apo-1 cDNA as a probe, we have molecularly cloned and characterized the human Fas chromosomal gene. The gene consists of nine exons and spans more than 26 kilobases of DNA. The lengths of introns vary from &gt; 14 kilobases at the 5' end of the gene to 152 base pairs upstream of the exon encoding the transmembrane domain. The domain structure of the human Fas is encoded by an exon or a set of exons. Primer extension analysis revealed three major transcription initiation sites. The promoter region lacked canonical "TATA" and "CAAT" boxes but was a "GC-rich" sequence, and contained consensus sequences for AP-1, GF-1, NY-Y, CP-2, EBP20, and c-myb. These data provide the first characterization of the human Fas gene and insight into its regulatory region.
Ontogeny of TCR V beta 1 expression revealed novel invariant alternative transcripts.
Authors: Dunon D , Schwager J , Dangy J P , Imhof B A 
Published: December 2022

Abstract
Analysis of TCR-beta gene recombination and expression was performed by quantitative PCR amplification technique throughout chicken embryogenesis and development. Our data demonstrated that TCR V beta 1 promoters were turned on by day 10 of embryogenesis, 2 days before detection of TCR-beta gene recombination. The V to D recombination step was first detected by day 11 of embryogenesis whereas DJ and V(D)J rearranged genes were detected 1 day later, on day 12 of embryogenesis. Thus, transcription of unrearranged TCR-beta genes in chickens precedes the expression of V(D)J recombinase activity as in mammals. In contrast, although TCR-beta rearrangement starts with the D to J recombination step in mammals, it can start either by the VD or the DJ step in chickens. Furthermore, reverse transcriptase-PCR amplification of TCR-beta transcripts revealed the presence of two kinds of alternative transcripts. These novel alternatively spliced products appeared in thymocytes from embryonic thymus during colonization periods and were absent in transformed T cell lines. Splicing sites are located in the middle of V beta 1 segments and lead to delta V beta 1-C beta and delta V beta 1-D beta-J beta-C beta transcripts. delta V beta 1-C beta transcripts might lead to synthesis of invariant truncated TCR beta-chains containing the aminoterminal portion of the V beta 1 region followed by the C beta region. Because this type of splicing can be generated by using all known V beta 1 members, these invariant forms could play a role in thymocyte development.
Activation of the 55 kDa TNF receptor is necessary and sufficient for TNF-induced liver failure, hepatocyte apoptosis, and nitrite release.
Authors: Leist M , Gantner F , Jilg S , Wendel A 
Published: December 2022

Abstract
The systemic inflammatory response is characterized by release of circulating TNF which may cause multiorgan failure including septic liver failure. We studied TNF signaling in an appropriate in vitro system with primary murine hepatocyte cultures from normal and genetically altered animals. Either one of the three different TNF species, huTNF-alpha, huTNF-beta, or muTNF-alpha (at concentrations &gt; 1 ng/ml) induced direct hepatocytotoxicity preceded by DNA fragmentation in cells prepared from wild-type C57BL mice. TNF-induced cytotoxicity was preceded by oligonucleosomal DNA fragmentation. Further cellular responses to TNF exposure were induction of nitric oxide synthase and secretion of serum amyloid A. None of the above events occurred in hepatocytes lacking the gene for the 55-kDa TNF receptor (TNF-R1), even after stimulation with &gt; 1 micrograms/ml TNF. However, selective stimulation of the TNF-R1 in wild-type hepatocytes with huTNF-alpha elicited a pattern of responses essentially similar to that seen with muTNF-alpha. We obtained analogous results when we examined the hepatotoxicity of TNF in D-galactosamine-sensitized mice, i.e., DNA fragmentation and liver failure was noted in wild-type mice, whereas TNF-R1-deficient mice were completely resistant. We conclude that the TNF-R1 is not only necessary, but also sufficient for TNF signaling in murine hepatocytes.
Endotoxin-mediated dendritic cell release from the intestine. Characterization of released dendritic cells and TNF dependence.
Authors: MacPherson G G , Jenkins C D , Stein M J , Edwards C 
Published: December 2022

Abstract
Dendritic cells (DC) acquire Ag in peripheral tissues and transport it to lymph nodes where they efficiently activate resting T cells. We have shown that i.v. endotoxin causes increased release of intestinal DC into lymph. In this paper we further characterize the release of DC and the properties of the released cells. A total of 50 micrograms of endotoxin injected i.v. causes an increase in DC output within 6 h that peaks between 12 and 24 h, with a maximum output of 8 to 15 times normal. At the same time lymphocyte output is markedly decreased. The increased output of DC is followed by a decrease to subnormal levels. The stimulated release of DC is almost totally blocked by a monoclonal anti-TNF-alpha Ab. A second injection of TNF-alpha does not result in further DC release. DC are not released from lymph nodes into efferent lymph by endotoxin. DC collected from lymph after endotoxin treatment show increased expression of the p55 IL-2 receptor and the OX48 Ag but otherwise resemble normal lymph DC. In functional assays they show no significant differences from normal in their ability to stimulate a MLR or to present Ags to sensitized T cells. Immunocytochemistry with the use of MRC OX62 suggests that the DC are released into lymph from the lamina propria of the small intestine. The stimulated release of DC mediated by TNF-alpha may be important in regulating Ag presentation in lymph nodes draining inflammatory sites.
A Th0/Th2-like function of CD4+CD7- T helper cells from normal donors and HIV-infected patients.
Authors: Autran B , Legac E , Blanc C , Debré P 
Published: December 2022

Abstract
We previously reported the expansion during HIV infection of a subset of CD4+ T cells characterized by a lack of CD7 cell surface expression. This CD4+CD7- subset showed in normal donors a lower cell proliferation than CD4+CD7+ autologous cells after CD3 triggering or CD28 costimulation. Our aim was to further characterize the Th function of this CD4+CD7- T cell subset, both in normal donors and in HIV-infected patients. Their CD4+CD7- cell proliferation and cytokine secretion were analyzed after cell-sorting and co-stimulation of the CD3 and CD28 pathways. In normal donors, the IL-2 produced by CD4+CD7- cells in response to a CD3 plus CD28 costimulus represented 50 +/- 28% of the autologous CD4+CD7+ cell IL-2 secretion. In addition, the CD4+CD7+ T cells produced higher amounts of IL-4 and IL-10 than the CD4+CD7+ cells with mean CD4+CD7-: CD4+CD7+ ratios of 5.4 +/- 4.5 and 26 +/- 25, for IL-4 and IL-10, respectively, whereas the IFN-gamma production was similar in both subsets. After a triggering of the CD3 complex alone, significant amounts of IL-2 were detectable in CD4+CD7+ cell supernatants only; conversely, IL-4 and IL-10 could be detected only in the culture medium from CD4+CD7- T cells. This profile of cytokine production was maintained both over time and at the clonal cell level in the CD4+CD7- T cell subset. In HIV-infected patients, the CD4+CD7- T cell expansion observed in relationship with disease progression was associated to an in vivo activation of the CD4+CD7- cells, as assessed by cell surface expression of the HLA-DR, CD25, CD71, and CD57 markers. The CD4+CD7- T cells from HIV-seropositive patients showed the same imbalance of cell proliferation and IL-2, IL-4, and IL-10 production as observed in normal donors despite low levels of proliferation and cytokine production. Together, our data indicate that the lack of CD7 expression defines a CD4+ Th cell subset with a Th0/Th2-like profile of cytokine secretion in normal individuals. The CD4+CD7- subset is expanded during HIV infection and characterized by the same although impaired profile of cytokine production. These CD4+CD7- T cells might play a role in the Th cell dysfunctions observed in HIV infection.
Influence of IL-1 receptor blockade on the human response to endotoxemia.
Authors: Van Zee K J , Coyle S M , Calvano S E , Oldenburg H S , Stiles D M , Pribble J , Catalano M , Moldawer L L , Lowry S F 
Published: December 2022

Abstract
Although the experimental administration of IL-1 induces several aspects of the inflammatory response, such as fever, tachycardia, and acute phase proteinemia, the contribution of IL-1 to the human responses to injury or infection remains unclear. A specific IL-1R antagonist (IL-1ra), which effectively blocks the actions of IL-1, was utilized to evaluate the influence of endogenous IL-1 during experimental human endotoxemia. Eighteen healthy volunteers each underwent one control study day, followed 3 days later by one of three randomly chosen treatments: a 6-h infusion of IL-1ra alone (133 mg/h), 20 U/kg national reference endotoxin alone, or both endotoxin and IL-1ra infusion. IL-1ra administration alone was not associated with any observable response. Despite achieving high circulating levels of IL-1ra (34 +/- 3 micrograms/ml), there were no significant differences in hemodynamic parameters, core temperature, or resting energy expenditure in those endotoxemic volunteers receiving IL-1ra when compared with those who did not. Furthermore, leukocyte kinetic and circulating cytokine, acute phase protein, and endocrine responses were similar in both endotoxemic groups. However, IL-1 blockade did significantly reduce the subjective severity of symptoms experienced by the endotoxemic volunteers (p &lt; 0.05). This study demonstrates that an endogenous IL-1 response does not play a significant role in the hemodynamic, immunologic, and metabolic responses to mild endotoxemia in humans.
Distinct signal transduction in mouse CD4+ and CD8+ splenic T cells after CD28 receptor ligation.
Authors: Abe R , Vandenberghe P , Craighead N , Smoot D S , Lee K P , June C H 
Published: December 2022

Abstract
Current evidence suggests that recognition of Ag/MHC by the TCR alone is insufficient to lead to T cell proliferation or effector function. For a Th cell to produce sufficient IL-2 to allow autocrine-driven clonal expansion, there is a requirement for so-called "costimulatory" or "accessory" signals in addition to TCR ligation by Ag/MHC. Although the first signal delivered by TCR ligation has been well characterized, information regarding the biochemical nature of second signals is limited. In the present report, using a newly generated mAb specific for CD28, signal transduction by the CD28 receptor has been studied in mouse splenic T cells. When freshly isolated splenic T cells were assessed, cross-linking of CD28 by mAb did not induce increases in intracellular calcium concentration were assessed, cross-linking of CD28 by mAb did not induce increases in intracellular calcium concentration whereas TCR cross-linking was able to induce calcium mobilization. In contrast, when T cells were activated by phorbol ester treatment or by in vitro culture, CD28 ligation was able to induce calcium mobilization in 60 to 70% of splenic T cells. Unexpectedly, the CD28-induced calcium response was mainly limited to T cells of the CD4+ subset, whereas both CD4+ and CD8+ T cell subsets showed increases in [Ca2+]i of similar magnitude after CD3 epsilon ligation. The temporal nature of the CD28-induced signal was also different from TCR-induced calcium mobilization. CD28-induced signals were delayed in onset and sustained in duration in contrast to TCR signals that had short latency and brief duration. Differential expression of CD28 on the surface of activated CD4+ or CD8+ T cells did not appear to account for the differences in signal transduction between the two T cell subsets. The preferential responsiveness of the CD4+ T cell population to CD28-induced signaling was also observed in downstream events such as the induction of IL-2R, CD69 expression, and in cellular proliferation. These results indicate that the costimulatory signal delivered by CD28 may have fundamentally different biochemical properties in CD4 and CD8 T cell subsets, and therefore the functional role of CD28 may differ in these T cell subsets.