bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potent stimulation of monocytic endothelin-1 production by HIV-1 glycoprotein 120.
Authors: Ehrenreich H , Rieckmann P , Sinowatz F , Weih K A , Arthur L O , Goebel F D , Burd P R , Coligan J E , Clouse K A 
Published: December 2022

Abstract
Monocytes/macrophages play a critical role in the pathogenesis of HIV infection, both as targets for virus replication and as sources of production of multifunctional cytokines. Endothelins, peptides with potent vasoconstricting activities originally isolated from endothelial cells, are also produced and secreted by macrophages in a manner similar to that of other cytokines. In an attempt to explore the potential role of endothelins in HIV-infection, we investigated the effect of the HIV-1 envelope glycoprotein, glycoprotein 120, on monocytic endothelin-1 production. This glycoprotein has been identified as a potent stimulator of monokines such as TNF-alpha and IL-6, which have been implicated as potential mediators of HIV-encephalopathy. We found that glycoprotein 120, similar to LPS, stimulates the secretion of endothelin-1, as well as TNF-alpha, from macrophages in a concentration-dependent manner. Using reverse transcriptase polymerase chain reaction, we found that circulating monocytes in HIV-infected individuals show a distinct expression of the endothelin-1 gene that is not detectable in healthy controls, indicating chronic activation of this gene in HIV-infection. In addition, cerebral macrophages in patients with HIV-encephalopathy were strongly positive for endothelin. Thus, monocytic endothelins appear to be stimulated during HIV infection. Their potent vasoactive properties render them potential candidates for mediating alterations in the cerebral perfusion pattern associated with the AIDS dementia complex.
Induction of circulating IL-1 receptor antagonist by IFN treatment.
Authors: Tilg H , Mier J W , Vogel W , Aulitzky W E , Wiedermann C J , Vannier E , Huber C , Dinarello C A 
Published: December 2022

Abstract
This study was undertaken to determine whether IFN induce IL-1 receptor antagonist (IL-1Ra), a specific inhibitor of IL-1. Plasma samples were obtained from healthy volunteers (n = 5) and patients with chronic hepatitis C (n = 5) treated with IFN-alpha, and from patients with renal cell carcinoma (n = 6) treated with IFN-gamma and assayed for IL-1Ra by a specific radioimmunoassay. Both types of IFN were administered subcutaneously. In vitro studies were carried out with PBMC from healthy volunteers. A single, low and nontoxic dose (1 x 10(6) U) of IFN-alpha induced circulating IL-1Ra, which reached peak levels within 12 h. This effect was dose-dependent and more pronounced with a higher dose (5 x 10(6) U). Peak IL-1Ra levels 12 h after 5 x 10(6) U IFN-alpha were 4.16 +/- 0.35 ng/ml in healthy volunteers and 5.7 +/- 0.73 ng/ml in patients with chronic hepatitis C (difference not significant). Thereafter levels declined but remained elevated for 24 h. IFN-gamma treatment led only to a modest increase of circulating IL-1Ra even at a dose of 400 micrograms; this dose, however, was associated with side effects similar to those seen after injection of 5 x 10(6) U IFN-alpha. PBMC stimulated with IFN-alpha or IFN-gamma produced IL-1Ra in vitro. The induction of IL-1Ra may contribute to the antiviral, anti-inflammatory, and antiproliferative effects of IFN.
Recombinant IL-6 activates p42 and p44 mitogen-activated protein kinases in the IL-6 responsive B cell line, AF-10.
Authors: Daeipour M , Kumar G , Amaral M C , Nel A E 
Published: December 2022

Abstract
IL-6 is a multi-functional cytokine that utilizes 80-kDa ligand-binding and 130-kDa signal-transducing subunits to stimulate diverse cellular responses. Although IL-6R ligation has been associated with tyrosine protein phosphorylation and activation of an unidentified serine/threonine kinase, very little is known about the intermediary signaling events between the cell membrane and the nucleus. rIL-6 treatment of the human B cell line, AF-10, induced MAP kinase (mitogen-activated protein kinase) activity as determined by in vitro phosphorylation of microtubule-associated protein-2 (MAP-2) and the synthetic peptide APRTPGGRR, corresponding to amino acids 95-98 of bovine myelin basic protein. The kinetics of the response was rapid and dependent on the dose of rIL-6. The response was cytokine specific, did not require the presence of extracellular Ca2+, and was minimally affected by the presence of staurosporine. MAP kinase activation in AF-10 cells occurred in parallel with appearance of 42- and 44-kDa tyrosine phosphoproteins (p42 and p44). Moreover, MAP kinase activation was diminished when AF-10 cells were stimulated with rIL-6 in the presence of tyrosine protein kinase inhibitors, genistein and geldanomycin. p42 and p44 co-electrophoresed on SDS-PAGE with extracellular signal-related kinase (ERK)-2, and ERK-1, respectively; both are members of the ERK family. In addition to p42MAPK and p44MAPK, rIL-6 also activated a MAP-2 kinase that eluted at a lower salt concentration (20 to 60 mM NaCl, peak I) from Mono-Q resin than p42MAPK (120 to 180 mM NaCl, peak II). The identify of this kinase is unknown but it is not an MPB kinase or a protein that exhibits immunoreactivity with anti-ERK antisera. In another IL-6-responsive B cell line, SKW6.4, rIL-6-activated peak I MAP-2 kinase but failed to activate ERK-2. The protein kinase C agonist, PMA, did, however, activate ERK-2 in SKW6.4 cells. These results show that the pleiotrophic cytokine, IL-6, activates p42MAPK/ERK-2 and at least one other serine/threonine kinase in B cell lines.
Mixed haplotype A beta Z/A alpha d class II molecule in (NZB x NZW)F1 mice detected by T cell clones.
Authors: Gotoh Y , Takashima H , Noguchi K , Nishimura H , Tokushima M , Shirai T , Kimoto M 
Published: December 2022

Abstract
We have tried to demonstrate the existence of a mixed haplotype MHC class II molecule in (NZB x NZW)F1 (B/WF1) mice. When a large panel of keyhole limpet hemocyanin-specific T cell clones derived from B/WF1 mice was analyzed, several clones were shown to be restricted by a F1-specific A beta Z/A alpha d class II molecule. Autoreactive A beta Z/A alpha d-specific T cell clones were also obtained. The ability of the association and expression of A beta Z with A alpha d was confirmed by hybridoma and transfection experiments. Hybridoma cell lines created by fusion of NZW (H-2z) spleen cells with M12.C3 (a A beta d- variant cell line derived from M12.4.1 (H-2d) B lymphoma) cells expressed A beta Z determinants. Transfection of A beta Z genomic DNA to M12.C3 cells resulted in the expression of A beta Z determinants. These hybridoma cell lines and transfectants were able to stimulate A beta Z/A alpha d-specific T cell clones, suggesting the expression of A beta Z/A alpha d molecules on the cell surface. However, attempts to demonstrate the existence of mixed haplotype MHC class II molecules in B/WF1 mice by two-dimensional (nonequilibrium pH gradient gel electrophoresis/SDS-PAGE) gel electrophoresis analysis with the use of anti-class II mAb failed to demonstrate the existence of mixed haplotype A beta Z/A alpha d or A beta d/A alpha z class II molecules in B/WF1 mice. Analysis of mixture of TA beta Z cell and B/WF1 spleen cell lysates immunoprecipitated by anti-A beta Z mAb suggested that the amount of haplotype mixed A beta Z/A alpha d molecules in B/WF1 spleen cells is less than 1/10 that of haplotype matched A beta/A alpha pairs. Our results suggest that, although undetectable by biochemical analysis, small amounts of mixed haplotype A beta Z/A alpha d molecules exist in B/WF1 spleen cells. Also, T cell clones which recognize them exists in B/WF1 mice. Because autoimmune symptoms of B/WF1 mice are shown to be related to heterozygosity at the H-2 region, autoreactive T cell clones which recognize the mixed haplotype A beta Z/A alpha d class II molecule might be involved for the induction of autoimmunity in B/WF1 mice.
Cholera toxin promotes B cell isotype switching by two different mechanisms. cAMP induction augments germ-line Ig H-chain RNA transcripts whereas membrane ganglioside GM1-receptor binding enhances later events in differentiation.
Authors: Lycke N Y 
Published: December 2022

Abstract
In a recent study we provided evidence that isotype switching in LPS-stimulated murine B cells was greatly enhanced by cholera toxin (CT). We found that CT acted synergistically with IL-4 to promote IgG1 differentiation at the gene transcriptional level by strongly enhancing the expression of germ-line gamma 1-RNA transcripts. In this study we ask which mechanisms are responsible for the isotype-switching effect of CT on B cells and which second messenger systems are involved in this process. We found that at least two different mechanisms are involved: 1) increased intracellular cAMP levels stimulated by the A subunit potentiates isotype switching early in differentiation by augmenting the formation of sterile germ-line gamma 1-RNA transcripts and 2) the binding of the nontoxic B subunit to the membrane GM1-ganglioside receptor promotes later stages of differentiation. Although the whole toxin gave up to a ninefold increase in IgG1 differentiation the cAMP-independent effect of rCTB gave at most a fivefold increase in IgG1 differentiation as compared to that seen with IL-4 alone. However, on a molar basis whole CT was at least a 1000-fold more efficient at promoting B cell switch-differentiation as compared to rCTB. Moreover, IL-4 did not stimulate cAMP in murine B cells and its effect on LPS-stimulated B cell differentiation was not decreased by inhibitors of cAMP-dependent protein kinases. However, CT's effect on B cell switch differentiation was blocked by inhibitors of protein kinases and could be partially mimicked by dibutyryl cAMP. In contrast to CT, the enhancing effect of rCTB on IgG1-differentiation was not affected by blocking of the protein kinases and the combination of rCTB and dBcAMP was as potent as the intact CT in promoting IL-4-stimulated IgG1 differentiation. Finally, the IL-4 pathway, but not the CT pathway, was sensitive to phorbol esters: In IL-4 plus LPS-stimulated B cell cultures IgG1 production was almost completely blocked by PMA. This inhibition was not associated with a decreased B cell proliferation or expression of germ-line gamma 1-RNA transcripts. The addition of CT, and to a significantly lesser extent rCTB, to these cultures enhanced IgG1-differentiation and expression of germ-line gamma 1-RNA transcripts to the same extent as in cultures without PMA. The existence of dual mechanisms operating together on B cell differentiation help to explain the strong adjuvant function by CT on IgG and IgA antibody responses after oral and parenteral immunizations.
Liver gamma delta T cells. TCR junctions reveal differences in heat shock protein-60-reactive cells in liver and spleen.
Authors: Roark C E , Vollmer M K , Cranfill R L , Carding S R , Born W K , O'Brien R L 
Published: December 2022

Abstract
The liver of mice contains elevated percentages of gamma delta T cells when compared with peripheral lymphoid organs. We have now analyzed these cells clonally, by generating a random collection of liver gamma delta T cell hybridomas and sequencing the productively rearranged TCR-gamma and -delta genes in each hybridoma clone. Examining C57BL/10 mice of various ages, we have found that over half of their normal gamma delta T cells are one of two types, V delta 4+ or V delta 6.3+. gamma delta T cell hybridomas generated from mouse liver contain clones that are "spontaneously" reactive, and respond to purified protein derivative from mycobacteria and to a 17-amino acid peptide from mycobacterial heat shock protein-60 (HSP-60). Like similar cells found in newborn thymus or adult spleen, all of the cells showing this HSP-60 reactivity pattern were found to express V gamma 1-J gamma 4-C gamma 4, most in conjunction with V delta 6-J delta 1-C delta, particularly with V delta 6.3. However, the gamma and delta junctional sequences of the V gamma 1/V delta 6+ cells isolated from adult liver differed from those found in adult spleen; being less diverse, their receptors instead resemble those of similar cells from newborn thymus. These data suggest that HSP-60-reactive gamma delta cells in adult murine liver and spleen are independent of each other and may be resident in their respective sites.
Rejection of an IA+ variant line of FBL-3 leukemia by cytotoxic T lymphocytes with CD4+ and CD4-CD8- T cell receptor-alpha beta phenotypes generated in CD8-depleted C57BL/6 mice.
Authors: Yoshimura A , Shiku H , Nakayama E 
Published: December 2022

Abstract
FBL-3N is an MHC class II Ag+ variant line that was obtained spontaneously during maintenance of Friend virus-induced leukemia FBL-3 in an athymic C57BL/6 (B6) mouse. Inocula of FBL-3N, but not the parental FBL-3 tumor, regressed after initial growth in CD8-depleted, syngeneic B6 mice. The cellular mechanisms by which FBL-3N was rejected in these mice were investigated in this study. We demonstrated that CTL with both CD4+ and CD4-CD8-TCR-alpha beta phenotypes were generated in mixed lymphocyte tumor cell culture spleen cells obtained from CD8-depleted B6 mice that had rejected FBL-3N by in vitro stimulation with mitomycin C-treated FBL-3N. After adoptive transfer of these CTL that were generated in vitro into athymic B6 mice, challenge with the FBL-3N tumor resulted in tumor regression after its initial growth. Thus, CD4+ and CD4-CD8-TCR-alpha beta CTL mediated rejection of the FBL-3N tumor in CD8-depleted B6 mice. Furthermore, the findings that depletion of B6 mice of CD4+ cells in addition to CD8+ cells abrogated the rejection of FBL-3N and generation of CTL in mixed lymphocyte tumor cell culture spleen cells suggest that CD4+ cells were required not only as a source of CD4+ CTL, but also as helper cells for generation of CD4-CD8-TCR-alpha beta CTL. Tumor Ag recognition of CD4-CD8-TCR-alpha beta CTL was restricted to Db, like that of classical CD8+ CTL, but the restriction appeared to be less obligatory than that of CD8+ CTL.
Residues that mediate DNA binding of autoimmune antibodies.
Authors: Radic M Z , Mackle J , Erikson J , Mol C , Anderson W F , Weigert M 
Published: December 2022

Abstract
Somatic mutations to arginine (R) are a common feature of a subset of J558 H chain genes that code for the majority of high-affinity, anti-dsDNA antibodies in autoimmune MRL/lpr mice. To examine the consequences of such amino acid substitutions on DNA binding, we reverted three somatic mutations of a prototypic anti-dsDNA H chain gene, VH3H9, and assayed the effect of those reversions by expression in a V lambda 1 L chain-only plasmacytoma line. Reversion of R53 eliminated virtually all dsDNA binding and sharply reduced ssDNA affinity. While the complete germ-line revertant of VH3H9 retained a low level of DNA binding, the substitution of R96, a product of N base addition in the third complementarity determining region (CDR3), with glycine (G) was sufficient to abolish measureable DNA specificity. Antibodies with higher affinity for DNA were generated by introducing arginines into VH3H9 at any one of four positions where somatic mutations to arginine had been identified by sequencing other anti-dsDNA J558 H chain genes. All four arginine mutants showed affinity increments consistent with their direct involvement in DNA binding, although one such mutant, K64R, required the simultaneous reversion of an adjacent aspartic acid (D) to the germ-line glycine. Two variants with three nongerm-line arginines showed further improvements in DNA affinity suggesting that their contributions to DNA binding may be additive. Molecular modeling of antibody and mutant F(ab) structures and calculations of their electrostatic potentials were used as an aid in interpreting the results and in predicting the location and size of possible combining sites.
Transfected Leishmania expressing biologically active IFN-gamma.
Authors: Tobin J F , Reiner S L , Hatam F , Zheng S , Leptak C L , Wirth D F , Locksley R M 
Published: December 2022

Abstract
Infection of susceptible BALB/c mice with Leishmania major leads to progressive infection with the failure to expand and activate Th1 CD4+ T cells that elaborate IFN-gamma, a critically implicated cytokine for control of disease. We used the recently described capacity to express foreign genes in trypanosomatids to introduce into Leishmania the murine IFN-gamma gene on a drug-selectable plasmid under the constitutive control of intergenic tubulin sequences. Several clones of L. major were established and demonstrated to contain IFN-gamma DNA and IFN-gamma RNA that was appropriately trans-spliced with the Leishmania-specific leader sequence, and to secrete IFN-gamma into the media. The secreted IFN-gamma was biologically active as assessed by up-regulation of class II MHC Ag and induction of macrophage nitric oxide synthase activity in a macrophage cell line. Infection of nude mice with IFN-gamma-containing organisms resulted in significantly slower progression of disease as compared to infection with organisms containing the empty plasmid, suggesting that biologically important activation of infected macrophages might be occurring in vivo. Infection of genetically susceptible BALB/c mice, however, did not impede the expansion of Th2 cells and the inexorable progression of disease. Despite the demonstration of increased levels of IFN-gamma transcription in vivo, induction of nitric oxide synthase in macrophages and expression of Ly-6, and IFN-gamma-inducible Ag, on CD4+ lymphocytes could not be shown. In all cases, organisms recovered from tissue amastigotes contained the IFN-gamma plasmid and secreted active IFN-gamma. The data confirm earlier studies that IFN-gamma alone is not sufficient to impede activation and maturation of Th2 cells in susceptible mice, even when targeted directly to the infected cell.
Prostaglandin E2 differentially modulates cytokine secretion profiles of human T helper lymphocytes.
Authors: Snijdewint F G , Kaliński P , Wierenga E A , Bos J D , Kapsenberg M L 
Published: December 2022

Abstract
PGE2 is a well known immunomodulator that has multiple effects on the immune system. We demonstrate that PGE2 selectively and dose dependently inhibits IL-2 and IFN-gamma production by mitogenically stimulated human PBL and CD4+ TLC, although at low concentrations IL-4 production is not affected and IL-5 production is even up-regulated. In the tested TLC, PGE2 induced a dramatic elevation (up to 85-fold) of the intracellular cAMP levels. The action of PGE2 may, therefore, be associated with elevation of intracellular cAMP levels, affecting IL-4 and IL-5 differentially from IL-2 and IFN-gamma production. To test this hypothesis we investigated cytokine production by TLC in the absence or presence of agents that affect cAMP levels, either directly (2'-O-dibutyrylcAMP) or through activation of adenylate cyclase (forskolin) or by blocking of phosphodiesterase (3-isobutyl-1-methyl-xanthine). Similar to PGE2, forskolin, 2'-O-dibutyrylcAMP, and 3-isobutyl-1-methyl-xanthine induced inhibition of IL-2 production by TLC and up-regulation of IL-5 production. However, in contrast to PGE2, these agents suppressed IL-4 production although IFN-gamma production was only moderately affected. No significant differences were found between intracellular cAMP levels of mitogenically stimulated Th1 cell clones, which predominantly secrete IL-2 and IFN-gamma, and those of Th2 cell clones, which mainly secrete IL-4 and IL-5. Our results indicate that PGE2 selectively modulates cytokine secretion profiles of human T cells and that elevation of cAMP levels has an important, but possibly not exclusive, regulatory role in this phenomenon.
Structural comparison and chromosomal localization of the human and mouse IL-13 genes.
Authors: McKenzie A N , Li X , Largaespada D A , Sato A , Kaneda A , Zurawski S M , Doyle E L , Milatovich A , Francke U , Copeland N G 
Published: December 2022

Abstract
The genomic structure of the recently described cytokine IL-13 has been determined for both human and mouse genes. The nucleotide sequence of a 4.6-kb DNA segment of the human gene is described. The human IL-13 gene (IL13) occurs as a single copy in the haploid genome and maps to human chromosome 5. A 4.3-kb DNA fragment of the mouse IL-13 gene (IL13) has been sequenced and found to occur as a single copy, mapping to mouse chromosome 11. Intrachromosomal mapping studies revealed that both genes contain four exons and three introns and show a high degree of sequence identity throughout their length. Potential recognition sequences for transcription factors that are present in the 5'-flanking region and are conserved between both genes include IFN-responsive elements, binding sites for AP-1, AP-2 and AP-3, and NF-IL 6 site, and a TATA-like sequence. Both genes map to chromosomal locations adjacent to genes encoding other cytokines, including IL-3, GM-CSF, IL-5, and IL-4, suggesting that IL-13 is another member of this cytokine gene family that may have arisen by gene duplication.
CTLA-8, cloned from an activated T cell, bearing AU-rich messenger RNA instability sequences, and homologous to a herpesvirus saimiri gene.
Authors: Rouvier E , Luciani M F , Mattéi M G , Denizot F , Golstein P 
Published: December 2022

Abstract
To detect novel molecules involved in immune functions, a subtracted cDNA library between closely related murine lymphoid cells was prepared using improved technology. Differential screening of this library yielded several clones with a very restricted tissue specificity, including one that we named CTLA-8. CTLA-8 transcripts could be detected only in T cell hybridoma clones related to the one used to prepare the library. Southern blots showed that the CTLA-8 gene was single copy in mice, rats, and humans. By radioactive in situ hybridization, the CTLA-8 gene was mapped at a single site on mouse chromosome 1A and human chromosome 2q31, in a known interspecific syntenic region. The CTLA-8 cDNA sequence indicated the presence, in the 3'-untranslated region of the mRNA, of AU-rich repeats previously found in the mRNA of various cytokines, growth factors, and oncogenes. The CTLA-8 cDNA contained an open reading frame encoding a putative protein of 150 amino acids. This protein was 57% homologous to the putative protein encoded by the ORF13 gene of herpesvirus Saimiri, a T lymphotropic virus. These findings are discussed in the context of other genes of this herpesvirus homologous to known immunologically active molecules. More generally, CTLA-8 may belong to the growing set of virus-captured functionally important cellular genes related to the immune system or to cell death and cell survival.