bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autoantibodies to human nuclear lamin B2 protein. Epitope specificity in different autoimmune diseases.
Authors: Brito J , Biamonti G , Caporali R , Montecucco C 
Published: December 2022

Abstract
The nuclear lamina of mammalian cells consists of three major proteins, lamins A, C, and B, and a fourth minor protein, lamin B2. Lamins belong to the family of intermediate filaments and are highly similar both in structure and primary sequence. They are organized in three well-defined domains: 1) a central alpha-helical rod, which is a secondary structure shared by all types of intermediate filaments, formed by three alpha-helices (coils 1A, 1B, and 2) and surrounded by 2) an amino-terminal head and 3) a carboxyl-terminal tail. Autoantibodies toward major lamin have been described previously in sera from patients with different autoimmune diseases. We chose an epitope mapping approach to further characterize the autoimmune response to nuclear lamin. Different lamin B2 domains were expressed as fusion proteins with the glutathione S-transferase and then used in immunoblotting experiments to analyze sera from patients with autoimmune diseases (chronic active hepatitis, SLE, rheumatoid arthritis, and polymyalgia rheumatica) and from healthy subjects. At a 1:1000 dilution, none of the control sera recognized any of the recombinant polypeptides. Conversely, reactive sera were present in all groups of patients. The ability to recognize a protein domain seemed to differ with the pathology. Most chronic active hepatitis sera were reactive to two or more lamin domains and reacting SLE sera always gave positive signals to coil 2 and/or coil 1B. Coil 2 was preferentially recognized by rheumatoid arthritis sera. Polymyalgia rheumatica sera differed from all of the others because of their low reactivity to the rod domain and preference for the C terminus, a lamin-specific domain.
Prevention of mercuric chloride-induced nephritis in the brown Norway rat by treatment with antibodies against the alpha 4 integrin.
Authors: Molina A , Sánchez-Madrid F , Bricio T , Martín A , Barat A , Alvarez V , Mampaso F 
Published: December 2022

Abstract
HgCl2 induces the synthesis of anti-GBM Abs with the development of glomerular and interstitial nephritis, as well as proteinuria, in the Brown Norway rat. The development of this autoimmune disease is a consequence of the appearance of an autoreactive T cell subset-inducing activation of B cells. The administration to mercury-treated rats of the mouse anti-human VLA alpha 4 HP2/1 mAb, which cross-reacts with the rat homologue integrin, completely abrogated the interstitial cell infiltrates. As demonstrated by peripheral blood analysis, this effect is not a result of the depletion of circulating leukocytes or leukocyte subsets. Interestingly, the administration of Abs specific for the alpha 4 integrin also highly reduced anti-GBM Ab synthesis, thus preventing detectable glomerular deposits and proteinuria. Our results confirm that in vivo alpha 4 functions in adhesive interaction of circulating leukocytes and vascular endothelium, and is centrally important in the extravasation and migration of T lymphocytes to sites of tissue injury. We also found a complete absence of interstitial cell infiltrates, together with a positive glomerular IgG lineal deposition pattern, when anti-GBM Abs were passively transferred to rats pretreated with anti-alpha 4 mAb, thus indicating an independent role of alpha 4 integrin in both extravasation of immune cells and production of autoantibodies. Furthermore, these in vivo findings provide preliminary evidence for the participation of the VLA-4 integrin in mediating the intercellular interaction of leukocytes regulating the production of Abs, most likely through the existence of additional yet unknown ligand(s).
Resistance of CTL to perforin-mediated lysis. Evidence for a lymphocyte membrane protein interacting with perforin.
Authors: Müller C , Tschopp J 
Published: December 2022

Abstract
Cytotoxic T lymphocytes are highly resistant to killing by their own cytolytic protein perforin. We have investigated the molecular basis of this self-protection mechanism. CTL withstood high dosages of perforin, when complete lysis was obtained with various tumor target cell lines. A peptide-specific CTL clone readily lysed tumor targets presenting the peptide, but was unable to kill the peptide-presenting CTL in spite of equal degranulation. With streptolysin O, a pore-forming lytic protein of bacterial origin, no difference in susceptibility between the various targets was detected. Perforin was radioactively labeled by using the Bolton and Hunter method without any loss of its lytic activity. Experiments performed at 4 degrees C revealed that, on all of the cells studied, binding of the labeled perforin to the membrane is reversible and strictly Ca(2+)-dependent. After a short exposure to 37 degrees C, perforin was no longer dissociated from cell membranes by EDTA. Although no correlation between susceptibility and the extent of perforin binding was detected, differences in the conformation of membrane-bound perforin were observed. Perforin adsorbed to resistant cells was cleaved by trypsin into a 55-kDa (C-terminal) and a 10- to 15-kDa (N-terminal) fragment, whereas this cleavage was not found on tumor cell-bound perforin. A portion of perforin was included in the Triton X-114 detergent phase at 4 degrees C on resistant CTLs only. Our results are compatible with the notion that a protective molecule, specifically expressed on CTLs, interacts with perforin, thereby rendering it lytically inactive.
Induction of IL-8 expression in T cells uses the CD28 costimulatory pathway.
Authors: Wechsler A S , Gordon M C , Dendorfer U , LeClair K P 
Published: December 2022

Abstract
IL-8, a potent chemotactic factor for neutrophil granulocytes and lymphocytes, is a proinflammatory cytokine secreted by a variety of cell types, including T cells. Stimulation of the CD28 cell surface molecule delivers costimulatory signals essential for lymphokine production in activated T cells via a conserved sequence element found in the promoter of several lymphokine genes. Anti-CD28-stimulated T cells produced significant amounts of IL-8; additionally, costimulation with anti-CD3 and anti-CD28 Abs resulted in a synergistic induction of IL-8 secretion. Sequence homology, single nucleotide mutations, and anti-CD28 Ab stimulation studies established that the NF-kappa B-like sequence in the promoter of the IL-8 gene functioned as a CD28 response element. Furthermore, cyclosporin A, but not rapamycin, blocked the synergistic induction of IL-8 expression achieved with anti-CD3 and anti-CD28 costimulation. The involvement of a CD28 response element in the induction of IL-8 expression in activated T cells may provide new insights into the pathogenesis and persistence of immune disorders characterized by increased levels of IL-8, such as psoriasis and rheumatoid arthritis.
Parasite-induced IL-12 stimulates early IFN-gamma synthesis and resistance during acute infection with Toxoplasma gondii.
Authors: Gazzinelli R T , Wysocka M , Hayashi S , Denkers E Y , Hieny S , Caspar P , Trinchieri G , Sher A 
Published: December 2022

Abstract
In vitro and in vivo studies were performed to assess the involvement of IL-12 in resistance to acute and chronic infection with an avirulent strain of Toxoplasma gondii. Our previous findings implicated macrophages as a major source of parasite-induced IL-12. This finding was confirmed by showing that peritoneal macrophages exposed to either live parasites or soluble tachyzoite Ags produce IL-12 protein. In mice, increased expression of IL-12 (p40) mRNA in both spleen and peritoneal cells was detected as early as 2 days postinfection. Treatment with neutralizing mAbs against IL-12 increased the susceptibility of C57BL/6, BALB/c, and severe combined immunodeficient (SCID) mice to acute infection, which resulted in 100% mortality within the first 15 days after parasite inoculation. In contrast, neutralization of endogenously produced IL-12 had no effect when given during chronic infection. In agreement with the survival data, treatment with anti-IL-12 resulted in decreased IFN-gamma and enhanced Th2 (IL-4 and IL-10) cytokine synthesis by splenocytes when given during acute, but not chronic, toxoplasmosis. Sorting experiments on spleen cells from acutely infected mice indicated that both CD4+ lymphocytes and NK1.1+/CD3- cells contribute to the early IFN-gamma response. In contrast, CD4+ cells were found to be the major source of the cytokine during chronic disease. Together, these results suggest that the stimulation of macrophage-derived IL-12 plays a major role in both the induction of resistance and Th1 cell subset selection in acute T. gondii infection, but may not be required to maintain established immunity.
Intracellular trafficking in Mycobacterium tuberculosis and Mycobacterium avium-infected macrophages.
Authors: Xu S , Cooper A , Sturgill-Koszycki S , van Heyningen T , Chatterjee D , Orme I , Allen P , Russell D G 
Published: December 2022

Abstract
Despite the potential role of the macrophage in the eradication of invading microbes, Mycobacterium species have evolved mechanisms to ensure their survival and replication inside the macrophage. Particles phagocytosed by macrophages normally will be delivered into acid lysosomal compartments for degradation. Mycobacterium must, in some way, avoid this fate by modulation of their phagosome. Immunoelectron microscopy of macrophages infected with Mycobacterium avium or Mycobacterium tuberculosis indicates that the vacuolar membrane surrounding the bacilli possesses the late endosomal/lysosomal marker, LAMP-1 (lysosomal-associated membrane protein-1), but lacks the vesicular proton-ATPase. Analysis of the intersection of the bacteria-containing vacuoles with the endocytic network of the macrophage supports previous studies indicating that these bacilli restrict the fusion capability of their intracellular compartments. The occurrence of vesicles containing lipoarabinomannan, discrete from those containing Mycobacterium, indicate that material does traffic out from the mycobacterial vacuole. To compensate for this loss of membrane, the vacuole must remain dynamic and fuse with LAMP-1-containing vesicles to maintain the density of this marker.
Molecular cloning and identification of the porcine cytolytic trigger molecule G7 as a Fc gamma RIII alpha (CD16) homologue.
Authors: Halloran P J , Sweeney S E , Strohmeier C M , Kim Y B 
Published: December 2022

Abstract
The G7 mAb binds a previously unidentified cytolytic trigger molecule on porcine NK cells and polymorphonuclear cells (PMN). This mAb has been shown to almost completely block PBL-mediated Ab-dependent cellular cytotoxicity and inhibit PMN-mediated Ab-dependent cellular cytotoxicity by approximately one-half, indicating a close functional association of the G7 molecule (to which the G7 mAb binds) with Fc gamma R function. This study was designed to identify the G7 molecule through molecular cloning of its cDNAs. The G7 protein was purified and peptide fragments subjected to amino acid sequencing. This information was then used in the PCR amplification of three cDNA fragments encoding a full-length G7 polypeptide. Amino acid sequences corresponding to peptides derived from G7 are observed within the deduced amino acid sequence of the individual clones confirming the specificity of G7 purification and PCRs. The specificity is also confirmed by reactivity of an antiserum raised against a synthetic G7 peptide to immunoprecipitated G7. Northern blot analysis indicates that a 0.9-kb G7 mRNA is expressed in porcine PMN, PBMC, macrophage, spleen, and lymph nodes but not in thymus or liver. Nucleotide and deduced amino acid sequence analyses indicate that G7 represents a porcine homologue to human Fc gamma RIIIA alpha. This is especially important in that G7 has been previously demonstrated to exist in a molecular complex with a novel molecule, PNK-E. The data suggests the presence of a novel Fc gamma RIII alpha molecular complex (G7/PNK-E) in the porcine system.
Islet-specific T cell clones transfer diabetes to nonobese diabetic (NOD) F1 mice.
Authors: Peterson J D , Pike B , McDuffie M , Haskins K 
Published: December 2022

Abstract
To investigate diabetes resistance to T cell-mediated disease transfer, we administered islet-specific T cell clones to the F1 progeny of nonobese diabetic (NOD) mice that were crossed with various nondiabetes-prone inbred mouse strains. We investigated four diabetogenic CD4+ T cell clones and all induced insulitis and full development of diabetes in (SWR x NOD)F1, (SJL x NOD)F1, and (C57BL/6 x NOD)F1 mice. In contrast, (BALB/c x NOD)F1 and (CBA x NOD)F1 mice were susceptible to disease transfer by some T cell clones but not others, and (C57/L x NOD)F1 mice seemed to be resistant to both insulitis and disease transfer by all of the clones tested. Disease induced by the T cell clones in susceptible F1 strains was age dependent and could only be observed in recipients younger than 13 days old. Full or partial disease resistance did not correlate with the presence or absence of I-E, different levels of Ag expression in islet cells, or differences in APC function. The results from this study suggest that there may be multiple factors contributing to susceptibility of F1 mice to T cell clone-mediated induction of diabetes, including non-MHC-related genetic background, the immunologic maturity of the recipient, and individual characteristics of the T cell clones.
CD4+ and CD8+ alpha beta, and gamma delta T cells are cytotoxic effector cells of beta 2-microglobulin-deficient mice against cells having normal MHC class I expression.
Authors: Udaka K , Marusić-Galesić S , Walden P 
Published: December 2022

Abstract
Despite original reports that describe the absence of CD8+ CTLs in mice having homozygous deficiency in the beta 2-microglobulin gene, strong cytotoxic activities against cells with normal beta 2-microglobulin expression were observed in these animals. This cytotoxicity was reproducibly induced by immunizations with allogeneic or syngeneic cells. MHC class II expression by the stimulator cells was not required. The effector population contained alpha beta T cells with CD4+ or CD8+ phenotypes, as well as gamma delta T cells with CD8- and CD8+ phenotypes. Both alpha beta T cell types recognized MHC class I molecules. The gamma delta T cells seemed to respond to molecules that are affected by the absence of beta 2-microglobulin, but that are not encoded by classical MHC loci.
Human TCR-gamma/delta alloreactive response to HLA-DR molecules. Comparison with response of TCR-alpha/beta.
Authors: Flament C , Benmerah A , Bonneville M , Triebel F , Mami-Chouaib F 
Published: December 2022

Abstract
We have analyzed the human gamma/delta T cell alloreactive response to class II HLA-DR molecules and attempted to compare this response with that mediated by the TCR-alpha/beta counterparts. Several gamma/delta CTL clones from a healthy individual were generated in mixed lymphocyte reactions against an EBV-transformed B cell line termed E418. Fine specificity and primary TCR structure of 10 representative clones (all CD4- CD8 +/-) were then determined. Functional studies, with the use of B cell lines homozygous for HLA-DR (DR1-10), indicated that all gamma/delta T cell clones specifically reacted with HLA-DR2 molecules. In addition, five clones were able to cross-react with subtypes of HLA-DR8. Extended panel target experiments, including lymphoblastoid cells expressing various HLA-DR2 subtypes, showed that the T cell clones displayed distinct fine specificities. Clones with broad (Dw2, Dw12, Dw21, Dw8.1, and Dw8.2) or in contrast, more restricted (DRB1*1501 or DRB1*1503) specificity were identified. Furthermore, amino acid substitutions at predicted peptide binding site position 30 and TCR-interacting position 67 of the DRB*1 beta-chain seemed to affect alloresponse of some T cell clones. With respect to TCR-gamma/delta structure, diversity in gene segment usage was observed, with the predominance of T cells using a V3-J gamma 2/V1-J delta 1+ receptor. A smaller fraction of the cells expressed TCR comprising V gamma 9 and V delta 1 regions. In contrast, the V delta 3 gene segment was used by a minority of the cells, and the V delta 2 was not expressed by any T cell clone. Together, the present data indicate that similarly to TCR-alpha/beta, human TCR-gamma/delta lymphocytes may recognize in a highly specific fashion a particular HLA-DR heterodimer. T cell clones cross-reacting with other HLA-DR molecules were also identified. Despite some degree of heterogeneity, V gene segment use by alloreactive clones seemed to be nonrandom. No obvious correlation between TCR gene use and HLA-DR alloreactivity could be identified. Moreover, our results suggest that similarly to TCR-alpha/beta cells, foreign MHC-bound peptides may contribute to TCR-gamma/delta alloreactive response.
A molecule expressed on accessory cells, activated T cells, and thymic epithelium is a marker and promoter of T cell activation.
Authors: Izon D J , Jones L A , Eynon E E , Kruisbeek A M 
Published: December 2022

Abstract
T cell maturation results in part from direct cell-cell interactions between developing thymocytes and thymic stromal cells. Identification of the cell surface molecules involved in these interactions has been approached by production of mAbs reactive to thymic stromal cell surface Ags. A mAb against one such Ag, mouse thymic stroma (MTS) mAb MTS 23, stains a subset of thymic medullary epithelium by immunohistology. In addition, it was found to detect, by flow cytometry, an Ag constitutively expressed on peripheral B cells and macrophages as well as thymic and splenic dendritic cells. This Ag was also up-regulated on T cells and thymocytes within 24 to 48 h after activation. We then investigated whether the Ag identified by MTS 23 may represent a functional accessory molecule. MTS 23 was able to block up to 75% of T cell proliferation in soluble anti-CD3 and Ag-induced responses in a dose-dependent manner, but not under conditions in which no APCs were required. The molecule detected by this mAb has an apparent molecular mass of 120 kDa under reducing and nonreducing conditions. On the basis of these molecular properties and expression pattern, it is therefore postulated that MTS 23 may detect a novel accessory molecule important for T cell activation. Its expression on thymic epithelium is consistent with the notion that T cell development is not solely a consequence of unique molecular interactions, but also of signals arising from combinations of interactions involving molecules also expressed extrathymically.
Activation of the Ig germ-line gamma 1 promoter. Involvement of C/enhancer-binding protein transcription factors and their possible interaction with an NF-IL-4 site.
Authors: Lundgren M , Larsson C , Femino A , Xu M , Stavnezer J , Severinson E 
Published: December 2022

Abstract
Ig isotype switching in B lymphocytes is preceded by transcription of the corresponding unrearranged, or germ-line (GL), CH gene. The promoter of mouse GL C gamma 1 transcripts has been shown to be located within a 349-bp KpnI/Bg/II fragment, extending from -147 to +202 bp relative to the first transcription initiation site. By the electrophoretic mobility shift assay, we have analyzed nuclear extracts from three B cell lines and splenic B cells for the presence of proteins binding to this fragment. We show that they give different patterns of DNA binding, implying significant complexity in the regulation of this locus. We focused on the sIgM+ mouse B lymphoma line L10A6.2 that has been shown able to confer responsiveness of the GL gamma 1 promoter to phorbol ester plus IL-4. Activation of this cell line results in altered expression of several nuclear DNA-binding complexes involving two members of the C/enhancer-binding protein (EBP) family of transcription factors, namely C/EBP beta (nuclear factor (NF)-IL-6/LAP) and Ig/EBP-1 (C/EBP gamma). The complexes bind to two C/EBP elements, one at about -115 bp and one near the first RNA start site. In normal B cells stimulated by LPS or IL-4, new complexes appear that bind to C/EBP and NF-IL-4 elements, respectively, located within the -125/-101 region. The -125/-101 segment previously has been shown to be required for transcriptional activation. We discuss these findings in relation to the presence of consensus C/EBP binding sites in other IL-4-regulated promoters.
TNF receptor signal transduction. Ligand-dependent stimulation of a serine protein kinase activity associated with (CD120a) TNFR60.
Authors: VanArsdale T L , Ware C F 
Published: December 2022

Abstract
TNF is a pluripotent cytokine that mediates activities through two distinct receptors of 55 to 60 kDa (CD120a, known as TNFR60) and 75 to 80 kDa (CD120b, known as TNFR80). These receptors share homology in the extracellular ligand binding region; however, the cytoplasmic domains are distinct and lack any inherent enzymatic activity, which suggests that ligand binding and subsequent receptor clustering leads to the association of active signaling molecules with TNFRs. To test this hypothesis, we isolated TNFRs by immunoprecipitation and examined the immune complexes for the presence of associated phosphoproteins and protein kinase activity. In the U-937 monocytic cell line, prelabeled with 32PO4, TNF induces the association of several phosphoproteins with TNFR60, but not TNFR80. The TNFR60 immune complexes also contain a TNF-dependent serine protein kinase activity, which was detected by an in vitro kinase assay, that phosphorylates proteins of 125, 97, 85, and 60 kDa, which are of apparent molecular masses that are similar to those of TNF-induced phosphoproteins that coprecipitate with TNFR60. Association of serine protein kinase activity with TNFR60 is rapid and dependent on the concentration of TNF. Proteins of molecular mass similar to the 125- and 97-kDa protein kinase substrates seem to be associated with TNFR60 immune complexes only after exposure of U-937 cells to TNF. The TNFR60-associated protein kinase activity is inhibited by staurosporine, but not by the protein kinase A and C inhibitors, HA-1004 and H7. Staurosporine greatly enhanced the sensitivity of U-937 cells to the cytotoxic effect of TNF. These results suggest a serine protein kinase(s), and, possibly, other TNF-dependent TNFR60-associated proteins may be involved in mediating signals through TNFR60 in response to ligand binding.