bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-9 production of naive CD4+ T cells depends on IL-2, is synergistically enhanced by a combination of TGF-beta and IL-4, and is inhibited by IFN-gamma.
Authors: Schmitt E , Germann T , Goedert S , Hoehn P , Huels C , Koelsch S , Kühn R , Müller W , Palm N , Rüde E 
Published: December 2022

Abstract
Dense CD4+ T cells isolated from naive mice produce only trace amounts of IL-9 when stimulated by immobilized anti-CD3 in combination with anti-CD28 Abs. In this situation, IL-9 production is significantly stimulated by TGF-beta and further enhanced by the addition of IL-4, which, by itself, has only a minimal influence. IFN-gamma was found to inhibit the enhancing effect of IL-4. However, increasing amounts of IL-4 in the presence of a constant concentration of IFN-gamma could overcome the inhibitory activity of IFN-gamma. The application of CD4+ T cells isolated from IL-2 knockout mice unequivocally revealed that IL-2 is essential for the production of IL-9 by T cells. In addition, the use of T cells from IL-4 knockout mice elucidated that the basic (IL-2 + TGF-beta) mediated IL-9 production is independent of IL-4. Therefore, our results demonstrate that optimal IL-9 production of naive dense CD4+ T cells is positively regulated at different levels: 1) by IL-2, which is essential for IL-9 secretion; 2) followed by TGF-beta, which promotes a considerable increase in IL-9 production above the level induced by IL-2; and 3) finally, by IL-4, which requires the presence of IL-2 and TGF-beta to strongly enhance the production of IL-9. IFN-gamma inhibits the production of IL-9 mainly at the level of IL-4 by neutralizing the effect of this cytokine.
Cytokine regulation by platelet-activating factor in a human B cell line.
Authors: Smith C S , Parker L , Shearer W T 
Published: December 2022

Abstract
TNF-alpha is an inflammatory cytokine produced by B cells that also impacts B cell differentiation and Ig secretion. We have investigated the regulation of the TNF-alpha gene in a human B cell line in response to platelet-activating factor (PAF), a potent phospholipid often produced in inflammatory reactions. We report here that PAF increases the RNA levels for the TNF-alpha gene in the human B cell line Ramos. This is mediated by an increase in the transcription rate and a longer half-life of the TNF-alpha transcripts. Induction of the TNF-alpha gene is rapid in these cells and independent of new protein synthesis. Despite increasing RNA for the TNF-alpha gene, PAF increases TNF-alpha protein levels only in the presence of a costimulus, such as PMA. We hypothesize that PAF acts at the transcriptional level to increase TNF-alpha RNA, but a post-transcriptional block acts to regulate protein production. We also report that PAF enhances PMA-induced TNF-alpha production from human peripheral B cells. This increase is maximal at 0.1 microM PAF and is blocked by PAF receptor antagonists. The ability of PAF to modulate cytokine production from human B cells provides further evidence that PAF has a role in B cell biology and suggests it may be important in conditions involving B cell-derived cytokines.
Macrophage-inactivating IL-13 suppresses experimental autoimmune encephalomyelitis in rats.
Authors: Cash E , Minty A , Ferrara P , Caput D , Fradelizi D , Rott O 
Published: December 2022

Abstract
Experimental autoimmune encephalomyelitis (EAE) is initiated by myelin basic protein (MBP)-specific CD4+ T cells of the Th1 phenotype that subsequently trigger the invasion of monocytes/macrophages into the brain. In this study, we evaluated the potential of human recombinant (hr) IL-13 to exert a protective effect on the development of EAE in Lewis rats. hrIL-13 is found to be a potent in vitro modulator of various rat macrophage functions, including an inhibition of the production of the proinflammatory cytokines IL-1 beta and TNF, and a simultaneous enhancement of MHC class II and CD4 receptor expression. Furthermore, hrIL-13 displayed a slight, but highly reproducible, inhibitory effect on the in vitro proliferative responses of encephalitogenic MBP-specific T cells stimulated in the presence of thymic APCs. Upon in vivo application of hrIL-13-secreting vector cells into MBP-immunized animals, the cytokine was capable of markedly suppressing the development of EAE, as assessed by a reduction of the mean duration, severity, and incidence of disease. This suppression of disease coincided with an only minimal reduction of MBP-directed T cell autoreactivity and no alteration in MBP-specific autoantibody production. We infer from these results that a strictly Th1-initiated immune disease can be attenuated efficiently by the administration of a cytokine that primarily targets cells of the macrophage/monocyte lineage and seems to exert no undesirable general suppression on either T cell or B cell immunoreactivity in vivo.
A humanized, bispecific immunoadhesin-antibody that retargets CD3+ effectors to kill HIV-1-infected cells.
Authors: Chamow S M , Zhang D Z , Tan X Y , Mhatre S M , Marsters S A , Peers D H , Byrn R A , Ashkenazi A , Junghans R P 
Published: December 2022

Abstract
HIV infection depletes the immune system of the coordinating functions of CD4+ T cells and APCs, whereas the population of CD8+ CTLs remains largely intact: functional but undirected. We have developed a humanized bispecific immunoadhesin-antibody (BIA) that redirects these remaining T cells to kill HIV-infected cells. This BIA expresses effector cell retargeting via a targeting activity that exploits the natural affinity of CD4 for gp120, and a recruiting activity that employs an anti-CD3 moiety to engage CTLs. The resultant molecule is 97% human in origin. In functional tests, this BIA mediated killing of HIV-infected cells using either pure CTL preparations, or whole PBL fractions that additionally include Fc gamma receptor-bearing large granular lymphocyte effectors. In contrast, a human anti-gp120 Ab induced target lysis via Ab-dependent cellular cytotoxicity (ADCC) only with large granular lymphocyte-containing fractions and not with CTLs. ADCC with this Ab was blocked in human serum, whereas BIA-mediated effector cell retargeting lysis of HIV-infected cells by CTLs was preserved. The affinity of the BIA for HIV-gp120 on infected cells and for CD3 epsilon on CTLs was derived in a flow cytometric Scatchard procedure. Relative to the bivalent parent molecules, CD4/gp120 affinity on cells was unchanged in the BIA (Ka 7 x 10(7) M-1), whereas the anti-CD3 affinity was diminished 50-fold (Ka 2 x 10(6) M-1 vs 1 x 10(8) M-1). Physical association of CD3+ effectors and gp120-expressing targets was confirmed by fluorescence microscopy and was dependent upon the presence of BIA and expression of target gp120. The unimpaired cytocidal activity of the BIA in the presence of serum highlights a potentially important advantage of this type of construct over native Abs for HIV-directed therapy.
T cell repertoire in patients with B chronic lymphocytic leukemia. Evidence for multiple in vivo T cell clonal expansions.
Authors: Farace F , Orlanducci F , Dietrich P Y , Gaudin C , Angevin E , Courtier M H , Bayle C , Hercend T , Triebel F 
Published: December 2022

Abstract
To characterize circulating T cell subpopulations in B chronic lymphocytic leukemia patients, TCR V alpha and V beta gene-segment use was analyzed by PCR using a panel of V gene-segment subfamily-specific oligonucleotide primers (V alpha 1-29/V beta 1-24). Virtually all V alpha and V beta subfamily specificities were expressed in these patients (nine stage A and four stage C), and the mean values obtained for each specificity were similar to those of a group of 13 healthy donors. Nonetheless, individual analysis revealed that unique V alpha or V beta gene-segment transcripts were overrepresented in patients compared with the control group. Overrepresentation of some TCR V beta chains was also detected by cytofluorometric analysis using a panel of 18 anti-V beta-specific mAbs. To further characterize these T cell subpopulations, we sequenced five different V beta-C beta PCR products in two selected stage A patients and found highly predominant recurrent transcripts in each of the five V beta specificities (50% to 100% of the analyzed sequences with identical V(D)J regions). These results were confirmed on bulk cDNA (i.e., without cloning) and extended to other V beta specificities (up to nine clonal expansions of 24 V beta specificities in one patient) and two other patients using a PCR-based method that determines V(D)J junction size patterns. Finally, it was observed that a V beta 19+ T cell subpopulation was clonally expanded in one patient to up to 30% of circulating T cells. This V beta 19+ CD8+ T cell clone was shown to specifically recognize the autologous tumor cells in vitro, as determined in cytokine release assays. Together, these results support the view that multiple expansions of unique T cell clones may derive in vivo from B chronic lymphocytic leukemia tumor-associated Ag stimulation.
TCR expression of activated T cell clones in the lungs of patients with pulmonary sarcoidosis.
Authors: Forrester J M , Wang Y , Ricalton N , Fitzgerald J E , Loveless J , Newman L S , King T E , Kotzin B L 
Published: December 2022

Abstract
Sarcoidosis is a systemic granulomatous disease of unknown etiology in which CD4+ T cells seem to be critically involved. In the lungs of patients with pulmonary disease, CD4+ T cells accumulate in large numbers, and a subset of these cells is activated. By using both quantitative PCR and anti-V beta mAbs, we analyzed the TCR repertoire of total and activated bronchoalveolar lavage T cells, the latter subset being defined by the ability to proliferate in short-term culture supplemented with IL-2. Overall, there was little difference when TCR V beta expression of freshly isolated lung and peripheral blood cells was compared in individual patients. Some individuals did demonstrate a modest increase in a few V beta-expressing subsets. However, after 1 to 2 wk of in vitro growth in IL-2-supplemented media, bronchoalveolar lavage cells from most patients, but not from any healthy individuals, demonstrated a selective expansion of particular V beta-expressing subsets. Interestingly, different V beta-bearing subsets were expanded in different patients. Junctional region sequencing indicated that the proliferating T cells in culture were strikingly oligoclonal and were derived from T cell clones already selectively expanded in vivo. These results provide evidence for a disease process that involves recognition of local Ag(s) by specific subsets of CD4+ T cells. Analysis of the Ag specificity of these IL-2-expanded populations is likely to provide insight into the pathogenesis of this disease.
Humanized antibody directed to the IL-2 receptor beta-chain prolongs primate cardiac allograft survival.
Authors: Tinubu S A , Hakimi J , Kondas J A , Bailon P , Familletti P C , Spence C , Crittenden M D , Parenteau G L , Dirbas F M , Tsudo M 
Published: December 2022

Abstract
IL-2Rs are expressed by T cells activated in response to foreign histocompatibility Ags but not by normal cells. This difference in IL-2R expression is exploited by blockade of IL-2Rs to achieve immunosuppression. High affinity IL-2Rs involve three subunits, IL-2R alpha, IL-2R beta, and IL-2R gamma. Murine Mik beta 1, a mAb that blocks IL-2 binding to IL-2R beta, was developed as an immunosuppressive agent. There was modest prolongation of cynomolgus cardiac allograft survival in animals treated with murine Mik beta 1 (mean survival 11.8 +/- 1.6 days compared with 8.2 +/- 0.4 days in untreated animals; p = 0.06). However, murine Mik beta 1 is ineffective in recruiting primate effector cells and is neutralized by monkey Abs directed toward the infused Ab. To circumvent these limitations, a humanized form of Mik beta 1, which is a largely human IgG1k Ab, except that murine hypervariable regions are retained, was developed. In vivo plasma survival of humanized Mik beta 1 was threefold longer than simultaneously administered murine Mik beta 1 (terminal t1/2, 104 +/- 10 h vs 37 +/- 2 h). Furthermore, humanized Mik beta 1 manifests Ab-dependent cellular cytotoxicity, an activity that is absent with the parental murine Mik beta 1. Graft survival was significantly prolonged by humanized Mik beta 1 treatment with survivals of 22, 22, 24, 27, 44, and &gt; 300 days (p vs control &lt; 0.01; p vs murine Mik beta 1 &lt; 0.01). Survival was not prolonged further (p &gt; 0.3) by the addition of humanized anti-Tac, which blocks interaction of IL-2 with IL-2R alpha subunits. There was no toxicity attributable to the use of Mik beta 1 Abs. Thus, humanized Mik beta 1 prolonged cardiac allograft survival in primates without toxicity and may be effective as an adjunct to standard immunosuppressive therapy.
Modulation of immunogenicity and antigenicity of proteins by maleylation to target scavenger receptors on macrophages.
Authors: Abraham R , Singh N , Mukhopadhyay A , Basu S K , Bal V , Rath S 
Published: December 2022

Abstract
We have maleylated proteins to target macrophage-specific scavenger receptors and have used this system to study changes in the epitopes and immunogenicity of such proteins. We show that maleylation of diphtheria toxoid (DT) induces targeting to macrophage scavenger receptors and enhances its immunogenicity. DT does not evoke detectable serum Ab responses upon injection as soluble protein. However, maleylated DT (mDT) does generate a significant Ab response. Furthermore, immunization with soluble mDT leads to a better T cell proliferative response in vitro than immunization with DT can generate, thereby demonstrating that maleylation leads to enhanced T cell immunogenicity in vivo. We also find that maleylation disrupts the native B cell epitopes of DT and creates new epitopes, because antisera to DT and mDT do not cross-react. At least some of the new epitopes generated are maleylation specific, because antisera against various maleylated proteins do cross-react. In contrast, maleylation does not significantly modify the repertoire of T cell epitopes generated from DT, because T cells generated by either DT or mDT immunization are cross-reactive, and both DT and mDT can stimulate T cells that are specific for single synthetic DT peptide. Maleylated proteins are better presented in vitro than are their native counterparts, and this enhancement of presentation is blocked by unrelated maleylated proteins. These results suggest that Ags targeted to scavenger receptors on macrophages by maleylation are better presented to T cells and are immunogenic in vivo without adjuvant.
Characterization of fibroblasts with a unique defect in processing antigens with disulfide bonds.
Authors: Merkel B J , Mandel R , Ryser H J , McCoy K L 
Published: December 2022

Abstract
A chinese hamster ovary (CHO) fibroblast, transfected with murine MHC class II genes, inefficiently stimulated CD4+ Th cells specific for OVA, hen egg lysozyme (HEL), and pork insulin which contain disulfide bonds. However, the fibroblasts elicited a T cell response to lambda repressor, which lacks disulfide bonds, and efficiently presented synthetic peptides. A somatic cell hybrid WALC, generated by fusing the hamster fibroblast with a murine L cell fibroblast, very efficiently processed OVA and HEL, suggesting that impaired processing was genetically complemented and was a recessive trait. The hamster fibroblasts were capable of processing two distinct denatured forms of OVA and carboxymethylated HEL, either as effectively or more efficiently than the B lymphoma cell. The CHO cells also displayed diminished disulfide reduction of an endocytosed [125I]tyramine linked to poly-(D-lysine) through a disulfide spacer compared with that of the cell hybrid, providing direct evidence for defective reductive cleavage by the CHO cells. Diminished aspartic acid-mediated proteolysis of Ag could not account for the phenotype, because cell lysates and separated organelles from the fibroblast possessed higher acidic aspartyl proteolytic activity than lysates and organelles from a B lymphoma cell. Thus, CHO cells exhibit a defect in processing Ag with disulfide bonds which is consistent with the impaired intracellular reduction of the disulfide bonds in endocytosed macromolecules.
Prostaglandin E2 promotes B lymphocyte Ig isotype switching to IgE.
Authors: Roper R L , Brown D M , Phipps R P 
Published: December 2022

Abstract
The mechanism by which PG of the E series (PGE) promote murine B lymphocyte IgE production was investigated. We previously reported that PGE, and other agents that increase intracellular cAMP, synergize with IL-4 and LPS to induce IgE and IgG1 production while inhibiting IgM and IgG3 synthesis. These data suggested that PGE may promote IL-4-induced class switching, but the mechanism by which PGE increases IgE synthesis remained obscure. We report here that 1) PGE increases (up to 14-fold) the number of splenic B cells secreting IgE, even though PGE mildly inhibits proliferation. 2) PGE acts on sorted surface IgM positive B cells, consistent with PGE acting on uncommitted B cells to promote class switching to IgE. 3) PGE synergizes with IL-4 to induce germline epsilon transcripts, demonstrating that PGE acts at the level of transcription in cells that have not yet switched to IgE. 4) In the presence of PGE, rearranged mature V(D)J epsilon mRNA transcripts can be detected earlier and at higher levels than with IL-4 and LPS alone. Taken together, these data provide strong evidence that PGE synergizes with IL-4 and LPS to direct isotype switching to the epsilon heavy chain gene in purified B lymphocytes. PGE is a potentially important in vivo immunoregulator, particularly with regard to IgE production and the genesis of allergy. In support of this hypothesis, there are numerous clinical conditions (hyper-IgE, trauma, sepsis, Hodgkin's lymphoma, arthritis) in which overproduction of PGE is coincident with elevated IgE titers.
A human anti-insulin IgG autoantibody apparently arises through clonal selection from an insulin-specific "germ-line" natural antibody template. Analysis by V gene segment reassortment and site-directed mutagenesis.
Authors: Ichiyoshi Y , Zhou M , Casali P 
Published: December 2022

Abstract
We analyzed the structural correlates underlying the insulin-dependent selection of the specific anti-insulin IgG1 kappa mAb13-producing cell clone, derived from a patient with insulin-dependent diabetes mellitus treated with recombinant human insulin. First, we cloned the germ-line genes that putatively gave rise to the expressed VH and V kappa segments and used them to generate the full (unmutated) "germ-line revertant" of the "wild-type" (somatically mutated) mAb13, using recombinant PCR methods and an in vitro human C gamma 1 and C kappa expression system. The full "germ-line revertant" bound insulin specifically and in a dose-saturable fashion, but with a relative avidity (AVrel) more than three-fold lower than that of its wild-type counterpart (Avrel, 1.69 x 10(-8) vs 4.91 x 10(-9) g/microliters). Second, we established, by reassorting wild-type and germ-line revertant forms of the mAb13 VH and V kappa segments, that the increased Avrel for insulin of mAb13 when compared with its full "germ-line revertant" counterpart was entirely dependent on the mutations in the VH not those in the V kappa chain. Third, we determined, by site-directed mutagenesis experiments, that of the three mutations in the mAb13 VH segment (Ser--&gt;Gly, Ser--&gt;Thr, and Ser--&gt;Arg at positions 31, 56, and 58, respectively), only Arg58 was crucial in increasing the mAb13 Avrel (from 1.44 x 10(-8) to 5.14 x 10(-9) g/microliters) and affinity (Kd, from 189 to 59 nM) for insulin. The affinity enhancement mediated by the VH segment Arg58 residue reflected about a threefold decrease in dissociation rate constant (Koff, from 4.92 x 10(-3) to 1.54 x 10(-3) s-1) but not an increase in association rate constant (Kon, from 2.60 x 10(4) to 2.61 x 10(4) M-1 s-1), and it contrasted with the complete loss of insulin binding resulting from the substitution of the VH segment Asn52 by Lys. The present findings suggest that human insulin, a self Ag, has the potential to recruit a natural autoantibody-producing cell precursor expressing a specific surface receptor for Ag in unmutated configuration, and drive it through affinity maturation. They also show that binding of insulin by such a receptor can be enhanced or completely abrogated by a single amino acid change.
Characterization of the mouse lymphotoxin-beta gene.
Authors: Lawton P , Nelson J , Tizard R , Browning J L 
Published: December 2022

Abstract
Lymphotoxin-beta (LT-beta) is a member of the TNF family of ligands which when expressed with lymphotoxin-alpha (LT-alpha, i.e., the original LT or TNF-beta) forms a heteromeric complex with LT-alpha on the cell surface. The mouse gene structure was determined by both cDNA cloning and analysis of a genomic DNA fragment encompassing the TNF/LT locus in the H-2 region of chromosome 17. The mouse and human genomic structures were found to be similar in terms of location in the class III region of the MHC; however, the mouse gene lacks one intron found in most members of the family. Both the cDNA and the genomic sequences revealed an altered splice donor in the conventional intron 2 position, rendering it nonfunctional. The altered gene retains an open reading frame such that an additional 66 amino acids are inserted into the stalk region connecting the transmembrane domain with the receptor binding domain encoded by exon 4 in this type II membrane protein. Northern analysis showed that this gene is expressed predominantly in lymphoid organs. The outlining of the complete mouse TNF locus will further studies of the relationship between these genes and immune function.
Several HLA alleles share overlapping peptide specificities.
Authors: Sidney J , del Guercio M F , Southwood S , Engelhard V H , Appella E , Rammensee H G , Falk K , Rötzschke O , Takiguchi M , Kubo R T 
Published: December 2022

Abstract
Herein we describe the establishment of assays to measure peptide binding to purified HLA-B*0701, -B*0801, -B*2705, -B*3501-03, -B*5401, -Cw*0401, -Cw*0602, and -Cw*0702 molecules. The binding of known peptide epitopes or naturally processed peptides correlates well with HLA restriction or origin, underscoring the immunologic relevance of these assays. Analysis of the sequences of various HLA class I alleles suggested that alleles with peptide motifs characterized by proline in position 2 and aromatic or hydrophobic residues at their C-terminus shared key consensus residues at positions 9, 63, 66, 67, and 70 (B pocket) and residue 116 (F pocket). Prediction of the peptide-binding specificity of HLA-B*5401, on the basis of this consensus B and F pocket structure, verified this hypothesis and suggested that a relatively large family of HLA-B alleles (which we have defined as the HLA-B7-like supertype) may significantly overlap in peptide binding specificity. Availability of quantitative binding assays allowed verification that, indeed, many (25%) of the peptide ligands carrying proline in position 2 and hydrophobic/aromatic residues at the C-terminus (the B7-like supermotif) were capable of binding at least three of five HLA-B7-like supertype alleles. Identification of epitopes carrying the B7-like supermotif and binding to a family of alleles represented in over 40% of individuals from all major ethnic groups may be of considerable use in the design of peptide vaccines.