bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the site of interaction of CD28 with its counter-receptors CD80 and CD86 and correlation with function.
Authors: Kariv I , Truneh A , Sweet R W 
Published: December 2022

Abstract
CD28 and CTLA-4 are homologue members of the Ig superfamily of molecules, containing a single V-like domain, transmembrane, and cytoplasmic regions. Both receptors associate with the counter-receptors CD80 and CD86, but the avidity of interaction for CD28 is about 20-fold lower than for CTLA-4. The interaction between CD28 and its cognate receptors provides a costimulatory signal for optimal T cell activation. Our previous mutational analysis of CD28 defined the highly conserved "MYPPPY" motif in the CDR3-region of the V-like domain as a key site of common and selective recognition. We have extended our analysis to cover all residues in the membrane distal loops of the V region, examining their effect on association with CD80/CD86 in cell adhesion and novel protein-based binding assays, and determining correlation between binding and functional response. Conservative F substitutions at either Y residue in the MYPPPY motif selectively reduced binding to CD86, but mutation of the three amino acids immediately C-terminal to Y 104 equivalently reduced binding to both co-receptors. The conservative F substitution of Y 26 in the CDR1-like region also reduced binding to CD80 and CD86. Other substitutions in the CDR1 loop and mutations spanning the CDR2 and DE loops had no effect. We conclude that the CDR1 and CDR3 regions contribute to a common binding site for CD80/CD86, and that the CDR3 region also carries determinants for selective recognition of these counter-receptors within the MYPPPY motif. Furthermore, for CD28, the strength of functional response, as measured by IL-2 production, directly correlates with binding avidity.
Nerve growth factor and cytokines mediate lymphoid tissue-induced neurite outgrowth from mouse superior cervical ganglia in vitro.
Authors: Kannan Y , Bienenstock J , Ohta M , Stanisz A M , Stead R H 
Published: December 2022

Abstract
Superior cervical ganglia (SCG) from neonatal mice were cultured with adult murine lymphoid tissue explants in Matrigel (Collaborative Biomedical, Bedford, MA). After 1 and 2 days in culture, many neurites grew toward thymus and spleen. Normal mesenteric lymph node (MLN) induced a smaller effect; however, activated MLN (isolated from mice 10 days after infection with Nippostrongylus brasiliensis; Nb-MLN-10d) caused significantly increased neurite outgrowth. To determine the roles of nerve growth factor (NGF) and cytokines in the promotion of neuritogenesis by lymphoid tissues, anti-NGF and various anti-cytokines were added to cocultures. Anti-NGF inhibited most of the neurite outgrowth toward thymus and spleen but only partially that toward Nb-MLN-10d. Anti-mouse IL-1 beta also significantly reduced the number of neurites growing toward thymus, spleen, and normal MLN. The number of neurites growing toward Nb-MLN-10d was significantly reduced by anti-IL-1 beta, anti-IL-3, anti-IL-6, or anti-GM-CSF. Exogenous IL-1 beta and IL-3 caused neurite outgrowth in single SCG cultures; and the IL-1 beta-, but not the IL-3-, mediated effect was completely blocked by anti-NGF. In one-day thymus/SCG cocultures, endogenous IL-1 was not detectable at concentrations sufficient to cause nerve growth; however, ample NGF was present in the thymic tissues and culture supernatants, but not in SCG. These data suggest that IL-1 mediates NGF production in lymphoid tissues, which in turn induces the growth of sympathetic nerves. Moreover, IL-3, IL-6, or GM-CSF produced during inflammation might also play important roles in the stimulation of nerve growth in vivo.
5-Oxo-eicosatetraenoate is a broadly active, eosinophil-selective stimulus for human granulocytes.
Authors: O'Flaherty J T , Kuroki M , Nixon A B , Wijkander J , Yee E , Lee S L , Smitherman P K , Wykle R L , Daniel L W 
Published: December 2022

Abstract
5-Oxo-eicosatetraenoate (5-oxoETE) is gaining recognition as a chemotactic factor for eosinophilic (Eo) as well as neutrophilic (Neu) polymorphonuclear leukocytes. We found that the eicosanoid was far stronger than C5a, platelet-activating factor (PAF), leukotriene B4 (LTB4), or FMLP in stimulating Eo chemotaxis. Moreover, it had weak intrinsic degranulating effects on otherwise unstimulated Eo, produced prominent degranulation responses in Eo primed by granulocyte-macrophage CSF, and enhanced the Eo-degranulating potencies of PAF, C5a, LTB4, and FMLP by up to 10,000-fold. Low picomolar levels of 5-oxoETE also induced Eo to activate mitogen-activated protein kinases (MAPKs), as defined by shifts in the electrophoretic mobility and tyrosine phosphorylation of two immunodetectable proteins, p44 and p42. 5-OxoETE was &gt; or = 100-fold weaker or unable to stimulate any of these responses in Neu. Finally, 5-oxo-15-hydroxy-ETE and 5-hydroxy-ETE activated both cell types, but were weaker than 5-oxoETE and had Eo/Neu potency ratios approaching unity. 5-OxoETE, thus, is uniquely potent and selective in promoting Eo not only to migrate, but also to release granule enzymes and activate MAPKs. By triggering MAPK activation, the eicosanoid may also influence the production of anaphylactoid lipids (e.g., PAF), arachidonic acid metabolites, and cytokines. 5-OxoETE therefore possesses a biologic profile well suited for mediating Eo-dominated allergic reactions in vivo.
Unstimulated peripheral blood mononuclear cells from patients with the hyper-IgD syndrome produce cytokines capable of potent induction of C-reactive protein and serum amyloid A in Hep3B cells.
Authors: Drenth J P , van der Meer J W , Kushner I 
Published: December 2022

Abstract
The hyper-IgD and periodic fever syndrome (HIDS) and familial Mediterranean fever (FMF) are both characterized by attacks of periodic fever accompanied by acute phase responses that are substantially higher in HIDS than in FMF. To determine whether this difference could be due to differences in production of acute phase protein-inducing mediators, we studied PBMC from HIDS and FMF patients in the inactive phase of disease. Unstimulated PBMC from patients with inactive HIDS released significantly more IL-1 beta, IL-6, and TNF-alpha than did PBMC from patients with FMF, but unstimulated PBMC from the latter group released significantly more IL-1 beta and IL-6 compared with controls. Conditioned medium (CM) derived from PBMC of patients with inactive HIDS induced significantly greater CRP production and significantly higher mRNAs for CRP and SAA in Hep3B cells than did CM derived from the PBMC of patients with inactive FMF. Stimulation of PBMC with LPS led to further increases in cytokine production and in acute phase protein-inducing ability in both patient groups and in controls. These findings suggest that the greater acute phase response seen in HIDS compared with FMF reflects greater production of acute phase protein-inducing cytokines in the former patients and indicates that PBMC from inactive HIDS patients are already activated in vivo. Finally, the finding of both quantitative and qualitative differences in cytokine production by unstimulated PBMC from HIDS and FMF patients supports the likelihood of different pathogeneses of these diseases.
Impaired production of both normal and mutant C1 inhibitor proteins in type I hereditary angioedema with a duplication in exon 8.
Authors: Ernst S C , Circolo A , Davis A E , Gheesling-Mullis K , Fliesler M , Strunk R C 
Published: December 2022

Abstract
In the autosomal dominant disorder type I hereditary angioedema, reduced levels of C1 inhibitor may be due in part to increased turnover and decreased synthesis of normal C1 inhibitor protein. A type I hereditary angioedema patient was recently described in whom the C1 inhibitor mutation consisted of a 20-bp duplication of nucleotides 1414 to 1433 in exon 8 that introduced a frame shift predicting the loss of a normal stop codon and the translation of a protein 52 amino acids longer than normal. In this study, we analyzed the expression of C1 inhibitor in fibroblasts obtained from a skin biopsy of this patient. Two proteins of approximately 78 and 94 kDa were found intracellularly, corresponding to the products of normal and mutated alleles, respectively. Pulse-chase analysis showed a complete lack of secretion of the mutated form. In addition, there was decreased extracellular production of the normal C1 inhibitor, suggesting either decreased secretion or increased intracellular catabolism of the normal protein because of the presence of the mutant allele. The production of other complement proteins was normal. This study provides a model for further analysis of autosomal dominant genetic disorders in which production of the functional protein may be affected by the product of the mutated allele.
B4B, a novel growth-arrest gene, is expressed by a subset of progenitor/pre-B lymphocytes negative for cytoplasmic mu-chain.
Authors: Ruegg C L , Wu H Y , Fagnoni F F , Engleman E G , Laus R 
Published: December 2022

Abstract
We subjected PBMC of normal adults to density fractionation to enrich for an immunoblast fraction that would include early immune lineage precursors. Differential display PCR experiments identified one transcript that is expressed specifically in this immunoblast fraction. This cDNA, designated B4B, encodes a novel gene product containing four putative transmembrane-spanning domains. B4B+ cells, detected with anti-B4B Ig, were found at very low frequency in PBMC (0.01%) and were enriched significantly in intermediate density fractions (0.1-1.0%). B4B+ cells were shown to be CD19+CD45+HLA-DR+ and negative for CD20, cytoplasmic mu-chain, CD3, CD16, CD56, CD34, and CD68 (monocyte), consistent with a progenitor/pre-B lymphocyte subset that does not express cytoplasmic mu-chain and thus may lack productive Ig rearrangement. This phenotypic description of the B4B+ subset agrees with our finding that the frequency of B4B+ cells was greatly increased in bone marrow (3-10%) as compared with PBMC (0.01%). The B4B polypeptide sequence exhibits significant homology to only one known protein, PMP-22/gas-3, a Schwann cell-specific protein that induces cell growth arrest. Transient expression of B4B specifically inhibited cellular proliferation by more than 50%. Based on its antiproliferative effect and pattern of expression restricted to a subpopulation of immature B cells, the B4B gene product may be involved in the elimination of B cells before productive VDJC rearrangement of Ig loci or, alternatively, in the growth arrest of transformed progenitor B cells.
Human T cells require IL-2 but not G1/S transition to acquire susceptibility to Fas-mediated apoptosis.
Authors: Fournel S , Genestier L , Robinet E , Flacher M , Revillard J P 
Published: December 2022

Abstract
The interaction between Fas ligand and Fas, both expressed on activated T cells, is the major pathway in the regulation of activation-induced cell death. However, activated T cells that express membrane Fas are initially resistant to anti-Fas-induced apoptosis and become susceptible only after proliferation in vitro. Since IL-2 is known to regulate activation-induced cell death, we studied the effect of IL-2 on anti-Fas-mediated apoptosis. Interference with the IL-2 pathway was achieved by 1) inhibition of cytokine synthesis using cyclosporin A or FK506, 2) neutralization of IL-2 by anti-IL-2 Ab, 3) inhibition of binding to IL-2R by CD25 mAb, and 4) blocking of IL-2R signaling by rapamycin. We show that Fas expression is independent of the IL-2 pathway, whereas Fas-mediated apoptosis does not develop in the presence of inhibitors of IL-2 production or signaling. While the addition of rIL-2 reversed the inhibitory effect of cyclosporin A and FK506, the addition of rIL-4, rIL-7, or rIFN-gamma did not, although these cytokines induced progression into the S phase of the cell cycle. Aphidicolin-treated activated T cells that do not progress into the S phase were susceptible to Fas-mediated apoptosis. Therefore, Fas-mediated apoptosis is controlled by signals generated by IL-2 in agreement with the reported alteration of apoptosis in mice deficient in IL-2 or IL-2R.
Functional CD40 ligand expressed by human blood dendritic cells is up-regulated by CD40 ligation.
Authors: Pinchuk L M , Klaus S J , Magaletti D M , Pinchuk G V , Norsen J P , Clark E A 
Published: December 2022

Abstract
We examined whether human blood dendritic cells (DCs) express a functional ligand for CD40 (CD40L). Human blood DCs expressed significant amounts of cell surface CD40L identical to that expressed on activated T cells, as detected by mAb to CD40L or a chimeric CD40.Ig fusion protein (CD40.Ig). Stimulation through CD40 up-regulated protein and mRNA CD40L expression in DCs, B cells, and B cell lines. CD40-mediated CD40L expression was inhibited by a protein tyrosine kinase inhibitor, herbimycin, in a dose-dependent manner, suggesting that the induction of CD40L expression via CD40 requires protein tyrosine kinase activity. CD40L surface expression correlated with constitutive or inducible levels of CD40L-specific mRNA, as determined by reverse transcribed PCR analysis (RT-PCR) using CD40L-homologous primers. Furthermore, CD40L on DCs was functional, since CD40L+ DCs, unlike CD40L- DCs, induced B cell IgG and IgA production, and this induction could be inhibited by blocking CD40L-CD40 interactions with mAb to CD40L. Thus, CD40L on DCs and CD40L induced by crosslinking CD40 may regulate B cell activation and maturation. The importance of DC CD40L expression on B cell function is discussed.
Development of CD4-CD8- alpha beta TCR+NK1.1+ T lymphocytes: thymic selection by self antigen.
Authors: Schulz R J , Parkes A , Mizoguchi E , Bhan A K , Koyasu S 
Published: December 2022

Abstract
Development of CD4-CD8- double negative (DN) alpha beta TCR+ cells were examined by cell transfer experiments using an Ly-5 congenic mouse system. Purified DN alpha beta TCR+ thymocytes injected intrathymically emigrated from the thymus to the spleen. The same cells did not return to the thymus when injected i.v. Similarly, peripheral DN alpha beta TCR+ cells from spleen and liver did not go to the thymus when injected i.v. but migrated to the spleen. These results indicate that DN alpha beta TCR+ thymocytes develop within the thymus and emigrate to peripheral organs. It is thus likely that peripheral DN alpha beta TCR+ cells are at least partly of thymic origin. DN alpha beta TCR+ thymocytes are unique in that they express a natural killer cell marker, NK1.1, which is not found on conventional T cells. We further examined the thymic selection of DN alpha beta TCR+NK1.1+ thymocytes by using an anti-HY TCR-transgenic (tg)/Rag-2(-/-) mouse system with H-2 backgrounds that were negative, positive, or nonselecting for conventional T cells. The number of DNtg TCR alpha beta+NK1.1+ cells was m prominent in male H-2b animals in which conventional T cells are deleted by HY/H-2Db recognition. Fewer DNtg TCR alpha beta+NK1.1+ cells were found in H-2b females (positive selecting background), and almost no DNtg TCR alpha beta+NK1.1+ cells were detected in H-2d animals (nonselecting background). Unlike conventional T cells, DNtg TCR alpha beta+NK1.1+ cells from anti-HY/Rag-2(-/-) H-2b mice express Fc(epsilon)RI(gamma) and CD3zeta as DN alpha beta TCR+NK1.1+ cells from normal C57BL/6 mice. Our results indicate that DNtg TCR alpha beta+NK1.1+ cells are positively selected by self Ag/MHC and emigrate to the peripheral organs.
Intracellular CD22 rapidly moves to the cell surface in a tyrosine kinase-dependent manner following antigen receptor stimulation.
Authors: Sherbina N V , Linsley P S , Myrdal S , Grosmaire L S , Ledbetter J A , Schieven G L 
Published: December 2022

Abstract
CD22 is a key accessory molecule for Ag receptor signaling in B cells that becomes tyrosine phosphorylated in the signaling process. CD22 associates with sIg and strongly amplifies sIg-induced signals. During B cell development, CD22 is initially expressed intracellularly, with surface expression appearing with IgD expression. We used confocal laser-scanning microscopy and flow cytometry to analyze CD22 translocation responses to signaling events. Cross-linking surface IgM (sIgM) induced rapid movement of CD22 to the cell surface in both Ramos and Daudi B cells, with a 50 to 100% increase in surface expression observed within 5 min of stimulation. The increase in CD22 surface expression was specific in that CD19 expression was not affected. Both cell surface and intracellular CD22 were directed toward the site of sIgM stimulation. Treatment with the phosphotyrosine phosphatase inhibitor bis(maltolato)oxovanadium(IV) also increased CD22 surface expression. The tyrosine kinase inhibitor tyrphostin A10 inhibited CD22 movement at concentrations that inhibited tyrosine phosphorylation of CD22 and other cellular proteins. In contrast to the B cell lines, mature peripheral blood B cells contained very little intracellular CD22 and showed no significant increase in surface expression following sIgM stimulation. The rapid directed movement of intracellular CD22 provides a new mechanism to dynamically regulate Ag receptor signaling, as well as CD22-mediated adhesion.
Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a potent inhibitor of nuclear transcription factor-kappa B activation by diverse agents.
Authors: Singh S , Natarajan K , Aggarwal B B 
Published: December 2022

Abstract
Viral replication, immune regulation, and induction of various inflammatory and growth-regulatory genes require activation of a nuclear transcription factor (NF)-kappa B. Agents that can block NF-kappa B activation have potential to block downstream responses mediated through this transcription factor. Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a quinone that has been shown to regulate a wide variety of activities that require NF-kappa B activation. In the present study, we examined the effect of capsaicin and its analogue, resiniferatoxin, on the activation of NF-kappa B induced by different agents including TNF. The pretreatment of human myeloid ML-1a cells with capsaicin blocked TNF-mediated activation of NF-kappa B in a dose- and time-dependent manner. Resiniferatoxin was at least eight times as potent as capsaicin in inhibiting NF-kappa B activation. Neither agent by itself activated NF-kappa B or affected the DNA-binding ability of NF-kappa B. Capsaicin also blocked phorbol ester-mediated NF-kappa B activation, but that mediated through okadaic acid was less effective, suggesting there is a difference in the mechanism of activation of NF-kappa B by different agents. Capsaicin treatment of cells also blocked the degradation of I kappa B alpha, and thus the nuclear translocation of the p65 subunit of NF-kappa B, which is essential for NF-kappa B activation. TNF-dependent promoter activity of I kappa B alpha, which contains NF-kappa B binding sites, was also inhibited by capsaicin. Overall our results indicate that capsaicin and its analogue inhibit NF-kappa B activation, and thus could be used as a potential target for drug development.
A residue in the center of peptide QL9 affects binding to both Ld and the T cell receptor.
Authors: Schlueter C J , Manning T C , Schodin B A , Kranz D M 
Published: December 2022

Abstract
The TCR from the alloreactive clone 2C recognizes p2C (LSPFPFDL)/Ld and QL9 (QLSPFPFDL)/Ld complexes with affinities of 2 x 10(6) and 10(7) M(-1). Recently, it was proposed that the Phe at position 4 of p2C is critical for recognition by the 2C TCR. To further characterize the role of this peptide position in binding to Ld and in recognition by the 2C TCR, we changed the corresponding peptide position in QL9 (position 5) to other amino acids. Binding affinities of these peptides for Ld and of the peptide/Ld complexes for a soluble single chain TCR were determined. Unexpectedly, it was shown that this peptide position has a significant effect on Ld binding (100-fold), with positively charged and hydrophobic residues having a beneficial effect and negatively charged residues having a detrimental effect. Measurements of the binding affinities of these peptide/Ld complexes for the 2C TCR showed that at 4 degrees C only a Tyr substitution at this position retained high affinity for the TCR. However, significant differences in TCR binding were observed among QL9 peptide variants at 4 degrees C compared with that at 37 degrees C. The influence of this peptide position on both Ld binding and TCR binding may suggest that the 2C TCR recognizes an Ld conformational determinant that is altered by interactions with the residue at position 5 of QL9. A strong correlation was also observed between peptide-Ld affinity and the ability of peptides to sensitize Ld target cells for lysis by CTL 2C. The results are considered in view of recent models on the relationship between T cell activity and TCR-peptide-MHC binding properties.
The granulomatous response in murine Schistosomiasis mansoni does not switch to Th1 in IL-4-deficient C57BL/6 mice.
Authors: Metwali A , Elliott D , Blum A M , Li J , Sandor M , Lynch R , Noben-Trauth N , Weinstock J V 
Published: December 2022

Abstract
IL-4 plays an important role in polarizing inflammation toward a Th2 response. It remains uncertain, however, whether IL-4 also serves to prevent expression of Th1 inflammation. Therefore, using a genetically pure C57BL/6 IL-4-deficient mouse, we studied the role of IL-4 in regulating the production of IFN-gamma and Th1 inflammation in the granulomas of mice infected with Schistosoma mansoni. In contrast to normal animals, IL-4 mutant mice generated smaller liver granulomas that contained fewer eosinophils and no mast cells. Collagenase-dispersed granuloma cells were analyzed by flow cytometry and cultured in vitro to measure cytokine and Ig production. Compared with control granuloma cells, IL-4-/- cells secreted only small quantities of IL-5 and IL-10. Also, there was impaired expression of the IL-4-dependent molecules IgE and IgG1 as well as B cell surface class II and CD23. Yet the granulomas of IL-4 -/- animals produced little IFN-gamma, IgG2a, or other molecules associated with Th1 inflammation even after Ag or anti-CD3 stimulation. Splenocytes from IL-4 -/- animals stimulated with schistosome Ag also failed to produce a Th1 response. Our data show that most aspects of the Th2 response in murine schistosomiasis are highly dependent on IL-4 production. But in the absence of IL-4, neither the natural local granulomatous response to schistosome ova nor the systemic response to soluble egg Ag switches to the type 1 phenotype. Thus the production of IL-4 early in the inflammatory response is not the only factor preventing Th1 expression in inflammation.