bluuebunny/crossref_metadata_2025_split huggingface dataset:
T cell receptor diversity in CTLs specific for the CTT-1 and CTT-2 minor histocompatibility antigens.
Authors: Johnston S L , Wettstein P J 
Published: December 2022

Abstract
Minor histocompatibility Ags (HA) and their associated immunogenic peptides provide a formidable barrier for successful transplantation, but there is virtually no information regarding the diversity of minor HA-specific TCRs. We have investigated the diversity of alpha- and beta-chains in TCRs specific for the CTT-1 and CTT-2 peptides that are immunodominant in CTL responses to multiple minor HA. CTLs were cloned after in vitro stimulation, and alpha- and beta-chain transcripts were amplified and sequenced to identify utilized V genes, complementarity-determining regions 3 (CDR3s), and joining region genes. Twenty-one unique CTT-2-specific TCRs were identified in 31 clones, and 22 CTT-1-specific TCRs were identified in 29 clones. A relatively limited number of V beta subfamilies were represented in these panels of TCRs, with Vbeta 5 and V beta8 genes expressed in multiple TCRs in each panel. Similar diversity was observed with V alpha usage, and V alpha4 subfamily usage was more prominent in CTT-2-specific TCRs than in CTT-1-specific TCRs. Neither alpha nor beta CDR3 regions exhibited prominent motifs or length restriction. However, CTT-1- and CTT-2-specific beta CDR3 regions included an excess of negatively over positively charged residues that were bimodally distributed among CDR3 positions. In fact, 50% of CTT-1-specific CDR3 regions included two negative charges separated by three to five amino acids. Despite the similarities in net charge of beta CDR3 regions, TCRs specific for these two minor HA peptides are relatively diverse and would expectedly withstand attempts at anti-TCR Ab-mediated immunosuppression.
IL-4-independent regulation of in vivo IL-9 expression.
Authors: Monteyne P , Renauld J C , Van Broeck J , Dunne D W , Brombacher F , Coutelier J P 
Published: December 2022

Abstract
We focused on the role of IL-4 in the regulation of the Th2 cytokine IL-9. In vivo, IL-9 mRNA was detected in lymph nodes after immunization with soluble Ags. IL-9 expression preceded that of IL-4, and was not affected in IL-4 knockout mice. In contrast, a significant decrease of IL-9 message was observed in IL-10-deficient mice, indicating a role for this cytokine in the induction of IL-9 production. Treatment with anti-CD4 Ab and analysis of purified CD4 cells confirmed that IL-9 was produced by CD4+ cells. Moreover, similarly to what has been reported for IL-4, IL-9 message induction was strongly decreased by infection with lactate dehydrogenase-elevating virus. IL-9 mRNA was also detected after in vivo stimulation with anti-CD3 Ab. In this model, IL-9 expression followed that of IL-4, but was not reduced in IL-4-deficient mice. This contrasts with in vitro stimulation in which, as reported in humans, IL-9 expression in lymphocytes incubated with anti-CD3 Ab and costimulatory molecules appeared as a late event, and was partly dependent on IL-4. In vitro IL-9 secretion was reduced significantly by addition of anti-IL-4 Ab, as well as in lymphocytes from IL-4 gene-deficient mice. Taken together, our results indicate that the Th2 cytokine IL-9 can be expressed by both IL-4-dependent and -independent pathways.
Functional effects of overexpression of protein kinase C-alpha, -beta, -delta, -epsilon, and -eta in the mast cell line RBL-2H3.
Authors: Chang E Y , Szallasi Z , Acs P , Raizada V , Wolfe P C , Fewtrell C , Blumberg P M , Rivera J 
Published: December 2022

Abstract
The rat basophilic leukemic (RBL-2H3) cell line was stably transfected with the endogenously expressed Ca2+-dependent protein kinase C-alpha (PKC-alpha) and -betaI and the Ca2+-independent delta and epsilon isoforms to study their functional roles. In addition, the Ca2+-independent PKC-eta was expressed. All transfected PKC isoforms translocated to the membrane-containing fraction in response to aggregation of the IgE-sensitized high affinity receptor for IgE (Fc epsilonRI) with the Ag dinitrophenyl(25)-BSA. All PKC transfectants, except PKC-eta, showed increased proliferative responses, and aggregation of Fc epsilonRI further enhanced the rate of proliferation. The PKC transfectants also showed increased phosphoinositide hydrolysis in response to Ag aggregation of receptors. No marked differences in the Ca2+ responses of the transfectants to Ag or thapsigargin were observed. Overexpression of PKC-alpha or -epsilon specifically inhibited receptor-dependent cytosolic phospholipase A2 (cPLA2) activity, whereas this activity was enhanced in the PKC-betaI transfectant. Analysis of the secretory response revealed that overexpression of PKC-betaI and -eta significantly enhanced secretion. A broad spectrum of cytokine mRNAs was detected in all transfectants, and overexpression of PKC-betaI significantly enhanced the receptor-dependent production of IL-2 and IL-6 mRNA. These studies identify PKC-alpha and -epsilon as negative regulators of cPLA2 activity and demonstrate the importance of PKC-beta as a positive modulator of secretion, cPLA2 activity, and cytokine production in this mast cell line.
CD154/CD40 and CD70/CD27 interactions have different and sequential functions in T cell-dependent B cell responses: enhancement of plasma cell differentiation by CD27 signaling.
Authors: Jacquot S , Kobata T , Iwata S , Morimoto C , Schlossman S F 
Published: December 2022

Abstract
CD40, a TNF receptor family member, plays a central role in T cell-mediated B cell activation. We have recently demonstrated that CD27, another TNF receptor family member, was also involved in B cell regulation and enhanced Ig production. In this report we compare CD27 and CD40 signals in B cell function. We selectively mimicked the effect of T cell help by addition to peripheral blood B cells activated with Staphylococcus aureus Cowan I strain and IL-2 of irradiated 300-19 cells transfected with either the CD70 (CD27 ligand) gene or the CD154 (CD40 ligand) gene, the vector alone, or both CD70 and CD154 genes. CD27 ligation induced only a slight increase in B cell proliferation compared with the dramatic enhancement induced by CD40 ligation; double ligation proved to be less efficient than CD40 ligation alone. In contrast, IgG production was increased only by CD27 ligation alone. Moreover, the CD27 signal was more efficient when it was given on day 2 of the culture rather than on day 0. Phenotypic analysis of the activated cells showed that CD27 ligation increased the percentage of cells showing a plasma cell profile (CD19-, CD38+), whereas upon CD40 ligation most of the cells still had a germinal center-like phenotype (CD19+, CD38+). Our results suggest that the CD27 and CD40 signals are not synergistic but, rather, are complementary and involve distinct steps of T cell-dependent B cell activation. CD27 may be more important in the induction of plasma cell differentiation at a time when the expansion phase has already occurred.
Introduction of exogenous class II trans-activator in MHC class II-deficient ABI fibroblasts results in incomplete rescue of MHC class II antigen expression.
Authors: Peijnenburg A , Gobin S J , van Eggermond M C , Godthelp B C , van Graafeiland N , van den Elsen P J 
Published: December 2022

Abstract
Previously, we have shown that fibroblasts established from type III bare lymphocyte syndrome patient ABI are characterized by the absence of MHC class II gene expression and a strongly reduced amount of MHC class I transcripts. Complementation analysis has suggested that the gene defective in these ABI fibroblasts is different from that encoding the class II trans-activator (CIITA), which has been attributed an essential role in both constitutive and inducible expression of MHC class II genes. In the present study it is shown by reverse transcriptase-PCR analysis that the amount of CIITA transcripts in ABI fibroblasts is greatly reduced compared with that in fibroblasts derived from a healthy individual. Transient cotransfection of a construct in which CIITA is under the control of a constitutive promoter with an HLA-DRA promoter-luciferase reporter plasmid resulted in enhanced luciferase expression in ABI fibroblasts. Furthermore, ABI fibroblasts stably transfected with CIITA re-express functional HLA-DR Ags, but do not express HLA-DQ and DP Ags at the cell surface. Comparison of these data with those obtained for normal fibroblasts and fibroblasts defective for CIITA indicate that the gene defect and the resulting lack of MHC class II expression in ABI fibroblasts can only partly be corrected by the introduction of CIITA. Furthermore, DNase I hypersensitivity analysis of ABI fibroblasts has revealed a closed chromatin structure in the promoter region of the MHC class II DRA gene. However, CIITA transfection resulted in an open DNA configuration, which suggests a role for CIITA in provoking changes in the chromatin structure of the DRA gene.
Activation and transdominant suppression of MHC class II and HLA-DMB promoters by a series of C-terminal class II transactivator deletion mutants.
Authors: Chin K C , Li G , Ting J P 
Published: December 2022

Abstract
The class II transactivator (CIITA) is a highly specific transcription factor that activates only genes known to be involved in the class II MHC processing pathway, including class II MHC, invariant chain, and HLA-DMA/B genes. In this work, we show the requirement of a new region in CIITA that is critical for its function. Deletion mutants lacking varying length of the C terminus show that the C-terminal 41 amino acids of CIITA are indispensable for the activation of both the conventional DRA and nonconventional DMB promoters. This region contains a highly charged stretch of amino acids that is homologous to a yeast transcription factor, repression activator protein-1 (RAP1)-interacting factor 1. Mutants lacking the C terminus were tested in a transdominant-negative assay to examine their capacity to block the wild-type CIITA function. Two of these deletion mutants suppressed the activity of endogenously expressed wild-type CIITA to activate both DRA and DMB promoters. It may be possible to utilize these mutants to modulate MHC class II and DM gene expression.
Effects of 5-oxo-6,8,11,14-eicosatetraenoic acid on expression of CD11b, actin polymerization, and adherence in human neutrophils.
Authors: Powell W S , Gravel S , Halwani F , Hii C S , Huang Z H , Tan A M , Ferrante A 
Published: December 2022

Abstract
Human neutrophils contain a highly specific dehydrogenase that converts 5-hydroxy-6,8,11,14-eicosatetraenoic acid to 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). 5-Oxo-ETE is a potent stimulator of calcium mobilization, chemotaxis, and aggregation in these cells and has similar effects on eosinophils. The primary objectives of the current study were to determine whether this compound could increase the surface expression of integrins and stimulate actin polymerization in neutrophils. 5-Oxo-ETE stimulated the expression of CD11b and, to a lesser extent, CD11c, on neutrophils, but had no significant effects on the expression of CD11a, CD16 (Fc gammaRIII), or CD32 (Fc gammaRII). Surface expression of CD11b in response to 5-oxo-ETE was maximal after 12 min and remained constant thereafter. The EC50 for this response (50 nM) was lowered to 20 nM by preincubation of neutrophils with PMA. 5-Oxo-ETE (EC50, 10 nM) also rapidly stimulated actin polymerization in neutrophils, with a maximal response at 20 s. This response was blocked by pretreatment of neutrophils with the Gi protein inhibitor, pertussis toxin, and by homologous desensitization due to preincubation with 5-oxo-ETE. However, preincubation with leukotriene B4 or platelet-activating factor had no effect on the response of neutrophils to subsequent addition of 5-oxo-ETE. The adherence of neutrophils to plasma-coated plastic was also stimulated by 5-oxo-ETE with a time course similar to that for the surface expression of CD11b. Low concentrations of PMA (0.3 nM) enhanced this response. These results raise the possibility that 5-oxo-ETE could contribute to the infiltration of neutrophils into inflammatory sites.
Cerebrospinal fluid cytokines in pediatric neuropsychiatric disease.
Authors: Mittleman B B , Castellanos F X , Jacobsen L K , Rapoport J L , Swedo S E , Shearer G M 
Published: December 2022

Abstract
This study examines cerebrospinal fluid from patients with three neuropsychiatric diseases of childhood for the presence and levels of several cytokines relevant to cell-mediated (type 1) and humoral (type 2) immunity. The patient groups include childhood-onset schizophrenia (n = 22), obsessive-compulsive disorder (OCD) (n = 24), and attention deficit hyperactivity disorder (n = 42). The cytokines examined include IL-2, IFN-gamma, TNF-beta/LT, IL-4, IL-5, IL-10, and TNF-alpha. Patients with OCD had a preponderance of type 1 cytokines. IL-4 was detectable only in samples from patients with schizophrenia. IL-10 was rarely detected and never in patients with OCD. Few patients with schizophrenia had detectable amounts of IFN-gamma in CSFL. We conclude that there is a relative skewing of CSFL profiles toward type 1 cytokines in patients with OCD, whereas in schizophrenia the relative preponderance is toward type 2 mediators. Patients with attention deficit hyperactivity disorder exhibited profiles intermediate between OCD and schizophrenia. We infer that cell-mediated immunity may be involved in the etiopathogenesis of OCD, whereas a relative lack of cell-mediated immunity and involvement of humoral immunity may be present in schizophrenia. These data provide a rationale for immune-based strategies of study and therapeutics in childhood neuropsychiatric disease.
HIV-1 gp120 induces an association between CD4 and the chemokine receptor CXCR4.
Authors: Ugolini S , Moulard M , Mondor I , Barois N , Demandolx D , Hoxie J , Brelot A , Alizon M , Davoust J , Sattentau Q J 
Published: December 2022

Abstract
For efficient entry into target cells, certain T cell-tropic HIV-1 isolates require both CD4 and the coreceptor CXCR4. However, the molecular interactions among CD4, CXCR4, and the HIV-1 envelope glycoproteins are only now being elucidated. Here we show that the binding of soluble gp120 from one macrophage-tropic and four T cell-tropic viruses to a CD4+, but not to a CD4-, T cell line, decreased the binding of an mAb specific for CXCR4 to its epitope, implying an interaction among gp120, CD4, and CXCR4. To confirm such an interaction, we conducted double- and triple-color confocal laser scanning microscopy on CD4+/CXCR4+ cells and determined the extent of CD4 and CXCR4 colocalization by a semiquantitative analysis. In the absence of gp120, a low level of constitutive colocalization between CD4 and CXCR4 was observed. Treatment with T cell-tropic-derived gp120 and, to a lesser extent, macrophage-tropic-derived gp120, increased the colocalization of CD4 with CXCR4, and triple staining indicated that gp120 was associated with the CD4-CXCR4 complexes. Cocapping of the gp120-CD4-CXCR4 complexes at 37 degrees C resulted in the cointernalization of a proportion of the gp120-CXCR4 complexes into intracellular vesicles. These data demonstrate that the binding of gp120 to CD4+ T cells induces the formation of a trimolecular complex consisting of gp120, CD4, and the HIV-1 coreceptor molecule CXCR4.
Regulation of antigen-specific IgE, IgG1, and mast cell responses to ingested allergen by mucosal tolerance induction.
Authors: van Halteren A G , van der Cammen M J , Cooper D , Savelkoul H F , Kraal G , Holt P G 
Published: December 2022

Abstract
Mucosal administration of soluble protein Ags results in profound immunologic nonresponsiveness, characterized by reduced production of Th1 and Th2 cytokines and concomitant suppressed Ig production. It has been suggested that Th2 cells are required for the induction and maintenance of this tolerogenic state. In this study, we show that oral tolerance induction abrogates subsequent Th2-driven Ag-specific IgE and IgG1 responses, while intranasal tolerance induction only blocks the production of IgE, but not IgG1. Consistent with suppressed IgE serum levels, elevated IFN-gamma production was observed in the spleens of tolerized mice. Moreover, both oral and intranasal tolerance induction were found to inhibit intestinal mast cell responses upon subsequent priming and intragastric provocation. Transfer of total splenocytes or purified CD4+, but not CD8+, T cells from intranasally tolerized mice clearly suppressed ongoing Ag-specific IgE, but not IgG1, responses in primed recipients. In addition, coadministration of IFN-gamma-neutralizing Abs completely blocked the transfer of suppression to primed recipients. These results show that Th2 cells can be subjected to tolerance induction, by inducing cross-regulatory, IFN-gamma-producing CD4+ T cells. Moreover, our results point out differences in the regulation of T cell-dependent Ag-specific IgE and IgG1 responses.
Tolerance to a dominant T cell epitope in the acetylcholine receptor molecule induces epitope spread and suppresses murine myasthenia gravis.
Authors: Wu B , Deng C , Goluszko E , Christadoss P 
Published: December 2022

Abstract
Myasthenia gravis (MG) is a T cell-dependent, Ab-mediated autoimmune disease. T cells reactive to a dominant peptide alpha 146-162 of acetylcholine receptor (AChR) alpha subunit participate in murine MG pathogenesis. To suppress the autoimmune response to AChR, a high dose of alpha146-162 peptide in IFA was administered parenterally as a tolerogen, after the development of a primary T cell immune response to AChR. This form of AChR T cell peptide tolerance suppressed the in vitro T cell proliferative response to AChR and its dominant alpha146-162 and subdominant alpha182-198 peptides through epitope spread. Administration of alpha146-162 peptide in IFA after the primary immune response to AChR also significantly suppressed the serum anti-AChR Ab of the IgG2b isotype and clinical incidence of MG in C57BL/6 mice. Furthermore, the production of IFN-gamma, IL-2, and IL-10 cytokines by AChR, alpha146-162, and alpha182-198 peptide-reactive cells was suppressed by alpha146-162 peptide tolerance, and the epitope spread observed could be attributed to the reduction in the above cytokine production. Therefore, AChR T cell-dominant peptide tolerance could be adapted in the Ag-specific therapy of MG.
Long-term inhibition of murine lupus by brief simultaneous blockade of the B7/CD28 and CD40/gp39 costimulation pathways.
Authors: Daikh D I , Finck B K , Linsley P S , Hollenbaugh D , Wofsy D 
Published: December 2022

Abstract
Murine lupus in NZB/NZW F1 (B/W) mice can be retarded by sustained administration of CTLA4Ig and by brief treatment early in life with mAb that block CD40/gp39 interactions. We sought to determine whether brief therapy with CTLA4Ig could provide sustained benefit in B/W mice and whether a synergistic effect could be derived by blockade of both the B7/CD28 and the CD40/gp39 pathways. We found that a short course of CTLA4Ig at the onset of disease produced only short-term benefit. However, when CTLA4Ig was combined with anti-gp39, there was long-lasting inhibition of autoantibody production and renal disease. Ten months after the 2-wk course of therapy, 70% of these mice were alive, compared with only 18% and 0% of those that received only anti-gp39 or CTLA4Ig, respectively. These findings demonstrate that brief simultaneous blockade of the B7/CD28 and CD40/gp39 costimulation pathways can produce benefit that lasts long after treatment has been discontinued.
The SH3 domain of Itk/Emt binds to proline-rich sequences in the cytoplasmic domain of the T cell costimulatory receptor CD28.
Authors: Marengère L E , Okkenhaug K , Clavreul A , Couez D , Gibson S , Mills G B , Mak T W , Rottapel R 
Published: December 2022

Abstract
Engagement of the transmembrane receptor CD28 potentiates T cell survival, proliferation, and activation. The biochemical basis by which CD28 controls these outcomes is unclear, although early events following cross-linking of the receptor are characterized by tyrosine phosphorylation of CD28 and other cellular substrates. We demonstrate that following CD28 ligation, a CD28-associated tyrosine kinase activity is increased in parallel to activation of the T cell-specific tyrosine kinase Itk (Itk/Emt), while Lck and Fyn kinase activities are not increased. We show that Itk forms an inducible complex with CD28, mediated by the SH3 domain of Itk and the diproline motifs of CD28. Site-directed mutagenesis of the N-terminal diproline motif of CD28 abrogates the association of CD28 with the SH3 domain of Itk, while mutations within the C-terminal diproline motif have little effect. Peptides corresponding to the N-terminal diproline motif were more efficient at abrogating the interaction between CD28 and the SH3 domain of Itk, than peptides corresponding to the C-terminal diproline motif. In addition, peptides corresponding to the N-terminal diproline motif of CD28 activated the tyrosine kinase activity of Itk to levels similar to those observed following Ab-mediated cross-linking of CD28. Together, our data show that the SH3 domain of Itk binds to a proline-rich motif within the cytoplasmic tail of CD28, and define a mechanism by which CD28 couples to and activates a downstream tyrosine kinase.
Partial activation of naive CD4 T cells and tolerance induction in response to peptide presented by resting B cells.
Authors: Croft M , Joseph S B , Miner K T 
Published: December 2022

Abstract
Tolerance is thought to occur when Ag is presented to T cells in the absence of costimulatory interactions from APC accessory molecules. Of the professional APC, the resting B cell may be the main tolerizing cell in vivo. We have analyzed several aspects of activation of naive transgenic CD4 cells stimulated with resting or activated B cells presenting peptide Ag. Similar results were obtained with stimulation from peptide presenting fibroblast APC lacking or expressing B7-1 with intracellular adhesion molecule-1. TCR ligation with little or no accessory molecule coreceptor engagement induced efficient blastogenesis; up-regulation of CD25, CD44, CD69, CD95 and CD71; and down-regulation of CD62L over a 48-h period. Accessory molecule help enhanced the expression of CD25, CD44, CD69, and CD71, but to very modest degrees. Only two molecules, CD40 ligand and IL-2, were found to be extremely dependent on accessory molecule help, with little or no expression evident with peptide presented on resting B cells or class II-positive fibroblasts. T cells induced on resting B cells expanded minimally over 3 days, and this was followed by extensive cell death and hyporesponsiveness of the resulting cells. These studies suggest that under tolerizing conditions, such as Ag presentation by resting B cells, much of the naive CD4 response is induced efficiently. Partial activation, however, may be the overall result due to the lack of CD40 ligand expression, which may regulate costimulatory activity in APC and, in turn, may contribute to limiting the production of IL-2 required for T cell expansion and survival.