bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunization of a rabbit with beta 2-glycoprotein I induces charge-dependent crossreactive antibodies that bind anionic phospholipids and have similar reactivity as autoimmune anti-phospholipid antibodies.
Authors: Kouts S , Wang M X , Adelstein S , Krilis S A 
Published: January 2023

Abstract
A rabbit immunized with beta 2-glycoprotein I (beta 2-GPI) produced Abs that bind to negatively charged phospholipids and to beta 2-GPI. After affinity purification of the Abs to beta 2-GPI, the dual reactivity could still be detected. Adsorption studies with a phosphatidylserine affinity column depleted phospholipid-reactive Abs, but beta 2-GPI reactivity was retained. The same pattern of reactivity was found with culture supernatants from rabbit anti-beta 2-GPI splenocytes fused with an immortalized rabbit cell line. The reactivity to negatively charged phospholipids is likely to involve ionic interactions, as high ionic strength buffers eliminated binding to anionic phospholipids, but not to beta 2-GPI. Affinity-purified anti-phospholipid (aPL) Abs from four of seven autoimmune patients bound anionic phospholipids in the absence of beta 2-GPI. However, in high ionic strength buffer, this binding was abolished in three patients and significantly reduced in the fourth. In contrast, affinity-purified aPL Abs from seven autoimmune patients bound to beta 2-GPI-coated plates, and binding in high ionic strength buffer was reduced only moderately in three patients. Therefore, autoimmune-type aPL Abs display anti-beta 2-GPI reactivity and charge-dependent binding to anionic phospholipids similar to affinity-purified rabbit anti-beta 2-GPI Abs.
Selective involvement of proteasomes and cysteine proteases in MHC class I antigen presentation.
Authors: López D , Del Val M 
Published: January 2023

Abstract
CTL recognize peptides derived from protein Ags bound to MHC-class I molecules. Proteasomes probably participate in the generation of these peptide epitopes. We investigated the role of proteasomes in the presentation of endogenously synthesized short viral proteins. To this end, we employed proteasome and cysteine protease inhibitors and two closely related recombinant vaccinia viruses that code for 17- and 19-amino acid-long products encompassing murine CMV 9pp89 epitope. Presentation of both minigene products required processing to shorter peptides and was independent of ubiquitination. Proteasomes were necessary for processing the 17-mer product, and cysteine proteases were not required. In contrast, the 19-mer product could be processed in parallel either by proteasomes or by cysteine proteases independently. These results highlight the diversity of alternative processing pathways even for short peptidic Ags, provide evidence for the involvement of cysteine proteases in MHC class I presentation, and show that cleavage by cysteine proteases is governed by sequences flanking the epitope.
Immunohistochemical analysis of in vivo patterns of TRAF-3 expression, a member of the TNF receptor-associated factor family.
Authors: Krajewski S , Zapata J M , Krajewska M , VanArsdale T , Shabaik A , Gascoyne R D , Reed J C 
Published: January 2023

Abstract
An immunohistochemical approach was used to explore the in vivo expression of TNF receptor-associated factor 3 (TRAF-3), a putative signaling protein that binds to the cytosolic domains of CD30, CD40, and lymphotoxin-beta receptors. TRAF-3 immunostaining was detected in many types of cells throughout the human body. TRAF-3 immunostaining was only rarely present in thymocytes but was found in the thymic epithelioreticular cells. Lymphocytes in the bone marrow were also typically TRAF-3 immunonegative, whereas myeloid progenitor cells and megakaryocytes were often TRAF-3 positive. Peripheral blood lymphocytes were mostly TRAF-3 immunonegative, while granulocytes were TRAF-3 immunopositive. Monocytes were strongly immunostained for TRAF-3, but macrophages in nodes typically contained little or no TRAF-3 immunoreactivity. Some lymphocytes within the germinal centers of secondary lymphoid follicles in normal and reactive nodes were TRAF-3 immunopositive, as were occasional interfollicular lymphocytes in the T cell regions of these organs, but most lymphocytes appeared to be TRAF-3 immunonegative or stained only weakly. Plasma cells, however, were strongly TRAF-3 positive. Stimulation of PBLs with anti-CD3 Ab induced marked increases in the steady state levels of TRAF-3 protein in vitro as determined by immunoblotting, while levels of TRAF-2 were unchanged, implying a dynamic regulation of TRAF-3 expression. The findings establish for the first time the cell type- and differentiation-specific patterns of expression of a member of the TRAF family of proteins.
Strength of TCR signal determines the costimulatory requirements for Th1 and Th2 CD4+ T cell differentiation.
Authors: Tao X , Constant S , Jorritsma P , Bottomly K 
Published: January 2023

Abstract
Differentiation of naive CD4 T cells into cytokine-secreting effector Th1 and Th2 cells is influenced by several factors. We have previously reported that the affinity of antigen for TCR and antigen dose can influence the differentiation of Th1 and Th2 cells. Several in vitro and in vivo models have demonstrated a role for the costimulatory molecules, B7-1 (CD80) and B7-2 (CD86), in the generation of distinct effector T cell responses. To determine whether the strength of TCR signaling controls the involvement of CD28 costimulation in selective CD4 T cell differentiation, naive CD4 T cells bearing a transgenic TCR are primed by a weak or strong TCR signal (signal 1) in the presence or absence of B7 costimulatory molecules (signal 2). In this system, IL-4-producing Th2 cells are generated by priming with a weak but not a strong TCR signal. Th2 cell differentiation is dependent on CD28/B7 interactions in that disruption of CD28/B7 interactions inhibits the priming of Th2 cells and cross-linking CD28 with anti-CD28 antibody augments the priming of Th2 cells. In contrast, however, IL-4-producing Th2 cells cannot be generated by priming with a strong TCR signal even in the presence of strong costimulation or high doses of IL-2. Thus, our results suggest that naive CD4 T cells are receptive to CD28-dependent IL-4 production only if they receive a weak TCR signal.
Exploiting the difference between intrinsic and extrinsic kinases: implications for regulation of signaling by immunoreceptors.
Authors: Wofsy C , Torigoe C , Kent U M , Metzger H , Goldstein B 
Published: January 2023

Abstract
When receptors must interact with an extrinsic kinase to initiate signaling, the kinase can play a regulatory role that is not available to intrinsic receptor kinases. Whether control is exercised at this level depends critically on the amount of kinase available to the receptors and on the potential for redistribution of the kinase during signaling. This study demonstrates that the high affinity receptor for IgE (Fc epsilonRI) on rat basophilic leukemia cells is regulated by its initiating kinase. We present a mathematical model that allows for the reversible recruitment of extrinsic kinases to phosphorylated immunoreceptor tyrosine-based activation motifs. By comparing model predictions to experimental time courses of phosphorylation, we infer that Lyn is limiting, that redistribution occurs after receptors are aggregated, and that the redistribution makes the relationship between tyrosine phosphorylation and receptor aggregation nonlinear.
Kappa and lambda rearrangement occur simultaneously in transformed pre-B cells.
Authors: Liu D , Jenab J , Rosenberg N 
Published: January 2023

Abstract
Murine B-lineage cells can express either kappa or lambda Ig light chains. However, most of these cells express kappa protein, a phenomenon that appears to be controlled in part at the level of gene rearrangement. This feature may reflect a preference for the kappa locus by the recombinase machinery, or it may indicate that kappa rearrangement begins before lambda rearrangement. These possibilities can be distinguished by measuring the kinetics with which light chain gene rearrangement at both loci actually occurs. To this end, we have used pre-B cells transformed by temperature-sensitive mutants of Abelson virus that undergo kappa and lambda gene rearrangement when shifted to the nonpermissive temperature. Competitive PCR analyses of rearrangement kinetics demonstrate that the kappa and lambda loci rearrange at about the same time in these cells. Consistent with this, some clones isolated from cells induced for a short period of time have rearranged only the lambda locus. However, the frequency with which lambda genes are rearranged is three- to sixfold lower than that with which kappa genes rearrange. These data indicate that the recombinase machinery targets both light chain loci at the same time, but acts preferentially at the kappa locus. The reduced ability of the recombinase machinery to target the lambda locus and selection pressures occurring during B cell development probably both contribute to the preferential usage of kappa genes in normal murine B lineage cells.
Identification of class I genes in cartilaginous fish, the most ancient group of vertebrates displaying an adaptive immune response.
Authors: Bartl S , Baish M A , Flajnik M F , Ohta Y 
Published: January 2023

Abstract
Sharks are members of the most primitive class of vertebrates (Chondrichthyes) shown to have an adaptive immune system. Suprisingly, however, class I genes have not been identified unambiguously in this taxon, and absence of class I loci or a failure to express class I genes might explain some of the relatively "weak" adaptive immune responses documented in cartilaginous fish. We report here the isolation of three unique cDNA clones from two different species of sharks that encode bona fide class I proteins. These clones exhibit different sequence and expression profiles indicating that they are likely to represent both classical and nonclassical class I lineages. In addition, our preliminary analysis suggests that there may be transfer of gene segments among shark class I genes over evolutionary time. The cloning of shark class I genes completes the identification of molecules that define the adaptive immune system (including Ig, TCR, and MHC class II proteins) in this taxon. Thus, simple models invoking a total absence of certain molecular hallmarks of the immune system to account for poor immune responsiveness in cartilaginous fish should be abandoned.
Immune responses induced by intramuscular or gene gun injection of protective deoxyribonucleic acid vaccines that express the circumsporozoite protein from Plasmodium berghei malaria parasites.
Authors: Leitner W W , Seguin M C , Ballou W R , Seitz J P , Schultz A M , Sheehy M J , Lyon J A 
Published: January 2023

Abstract
The circumsporozoite protein (CSP) is a target for effector Ab and cell mediated immunity against malaria parasites; DNA vaccination can induce both types of effector response. The immunogenicity and efficacy of two DNA plasmids expressing different amounts of Plasmodium berghei CSP were evaluated by immunizing BALB/c mice i.m. or epidermally and by varying the number of immunizations (one to three doses) and the interval between immunizations. Expanding the interval gave the strongest effect, increasing efficacy and antibody boosting, and, in the case of epidermal vaccination, promoting a switch in CSP-specific IgG isotypes from IgG1 to a balance with IgG2a. The strongest humoral immune response and the greatest level of protection were induced by vaccinating epidermally with high expresser plasmid, using a gene gun to administer three doses at 6-wk intervals. For this group, the mean, repeat-specific, prechallenge antibody titer among mice not infected after challenge was significantly higher than that in infected mice, but the mean prechallenge titers for antibody reactive with whole sporozoites were not significantly different. The interval-dependent induction of IgG2a antibodies by epidermal vaccination contradicts the widely held belief that antibody responses induced by this method are restricted to those that are Th2 dependent.
Glycoconjugates isolated from Trypanosoma cruzi but not from Leishmania species membranes trigger nitric oxide synthesis as well as microbicidal activity in IFN-gamma-primed macrophages.
Authors: Camargo M M , Andrade A C , Almeida I C , Travassos L R , Gazzinelli R T 
Published: January 2023

Abstract
In the present study, we investigated the role of glycosylphosphatidylinositol-anchored mucin-like glycoproteins (GPI-mucins) from Trypanosoma cruzi trypomastigotes in triggering the synthesis of nitric oxide as well as the microbicidal activity in murine macrophages. Our results show that GPI-mucins isolated from trypomastigote membranes are potent inducers of nitric oxide synthesis by IFN-gamma-primed macrophages, even at concentrations as low as 10 ng/ml. Our data also indicate the important role of glycosylphosphatidylinositol anchors from GPI-mucins as the second signal responsible for induction of nitric oxide synthesis by macrophages. To further investigate the role of these parasite molecules in inducing parasiticidal function, we cultured macrophages in the presence or absence of trypomastigote GPI-mucins and/or IFN-gamma and then infected these cells with either Leishmania spp. or T. cruzi. IFN-gamma was sufficient to induce microbial activity in macrophages infected with T. cruzi trypomastigotes. In contrast, killing of different species of Leishmania was further enhanced when macrophages exposed to IFN-gamma were also costimulated with trypomastigote-derived GPI-mucins. Our results also indicate that different glycolipids obtained from Leishmania major or Leishmania donovani (i.e., lipophosphoglycans or glycoinositolphospholipids) were unable to potentiate nitric oxide synthesis and/or microbicidal activity displayed by IFN-gamma-primed macrophages.
Recognition of the E-C4 element from the C4 complement gene promoter by the upstream stimulatory factor-1 transcription factor.
Authors: Galibert M D , Boucontet L , Goding C R , Meo T 
Published: January 2023

Abstract
Activation of complement gene expression plays a major role in the response to antigenic challenge. The induction of complement synthesis occurs primarily in liver and in macrophages and is mediated, at least in part, by increased transcription of the complement genes. For example, transcription of the C4 complement gene, which plays a crucial role in the complement pathway, is induced in response to acute inflammation or tissue injury. Previous work has defined the elements present in the C4 complement gene promoter that are required for its expression. Particularly important is an E-box motif, E-C4, that is conserved between the mouse, human, and rat promoters and that directed up to 90% of transcription from the mouse C4 promoter. Here we have purified the E-C4-binding factor to homogeneity using a novel and rapid affinity purification procedure. Following N-terminal microsequencing and subsequent isolation of the corresponding cDNA, the factor binding the E-C4 element was identified as upstream stimulatory factor-1 (USF-1), a basic helix-loop-helix-leucine zipper transcription factor. We also show for the first time that in vivo USF-1 is a phosphoprotein, but that phosphorylation of USF-1 is severely reduced in cells in culture. Moreover, the phosphorylated form of USF-1 binds DNA preferentially, indicating that phosphorylation may enhance the ability of USF-1 to bind DNA. The implications of USF-1 phosphorylation for C4 complement gene expression and transcription regulation are discussed.
IFN-gamma and IL-10 inhibit induction of IL-1 receptor type I and type II gene expression by IL-4 and IL-13 in human monocytes.
Authors: Dickensheets H L , Donnelly R P 
Published: January 2023

Abstract
The Th2-type cytokines IL-4 and IL-13 induce expression of a distinct subset of genes in human monocytes. These include Fc epsilonRII (CD23), 15-lipoxygenase, IL-1 receptor antagonist (IL-1ra), and type I and type II IL-1 receptors (IL-1R). IFN-gamma has been shown to inhibit induction of CD23 and 15-lipoxygenase in monocytes; however, the effects of IFN-gamma on type I and type II IL-1R gene expression have not been defined. We examined the effects of IFN-gamma on both basal and IL-4/IL-13-induced IL-1R gene expression in primary monocytes. IL-4 and IL-13 induced dose- and time-dependent increases in IL-1RI and IL-1RII mRNA levels. IFN-gamma decreased basal expression as well as the induction of these genes by IL-4 and IL-13. Inhibition of IL-1RI and IL-1RII mRNA levels by IFN-gamma was transcriptionally mediated, and correlated directly with decreased production of soluble IL-1RII. Furthermore, the ability to suppress IL-1RI and IL-1RII mRNA levels was not unique to IFN-gamma because IL-10 also inhibited expression of these genes in IL-4/IL-13-stimulated monocytes. Inhibition of IL-1R gene expression by IFN-gamma and IL-10 was not due to down-regulation of surface IL-4R because pretreatment with these cytokines did not decrease the number of IL-4 binding sites per cell. However, suppression of IL-1R gene expression by IFN-gamma and IL-10 was associated with decreased tyrosine phosphorylation and nuclear translocation of the IL-4/IL-13-inducible transcription factor, Stat6, suggesting a potential mechanism by which IFN-gamma and IL-10 may mediate their suppressive effects. These findings demonstrate that certain cytokines, including IFN-gamma and IL-10, antagonize the ability of IL-4 and IL-13 to induce increased expression of the IL-1RI and IL-1RII genes in monocytes.
Association of CD4+ T cell-dependent keratitis with genetic susceptibility to Pseudomonas aeruginosa ocular infection.
Authors: Kwon B , Hazlett L D 
Published: January 2023

Abstract
The role of T lymphocytes in susceptibility to Pseudomonas aeruginosa corneal infection was studied in inbred C57Bl/6 (B6) beta2-microglobulin+/+ (beta2m+/+) and beta2m-/- knockout (KO) mice on a B6 genetic background. The corneas of both B6 and KO mice perforated by 7 days postinfection (p.i.). Histopathology revealed a similar inflammatory response characterized by an infiltration of polymorphonuclear neutrophilic leukocytes by 24 h p.i. in both groups of mice. CD4+ and CD8+ (latter absent in KO) T cells were present in cornea by 3 days p.i., and by 5 days, IL-2R-positive cells were positively immunostained. Corneas of B6 beta2m+/+ mice depleted of CD4+ T cells and infected with P. aeruginosa did not perforate at 7 days p.i. vs mice depleted of CD8+ T cells or treated with an irrelevant mAb. Neutralization of IFN-gamma before infecting B6 mice prevented corneal perforation and was associated with a lower delayed-type hypersensitivity than in B6 mice similarly treated with an irrelevant mAb. These data provide evidence that a CD4+ T cell (Th1)-dominated response following P. aeruginosa corneal infection is associated with genetic susceptibility and corneal perforation in inbred B6 mice.
Homing of naive and memory T lymphocyte subsets to Peyer's patches, lymph nodes, and spleen.
Authors: Williams M B , Butcher E C 
Published: January 2023

Abstract
The specificity and efficiency of extravasation of subsets of memory and naive lymphocytes into organized lymphoid tissues has been the subject of recent controversy, but has not been directly assessed in physiologic systems. Here, we compare the lymphoid organ homing of naive and phenotypically defined memory T cells, focusing on memory subsets differentially expressing the integrin receptor alpha4beta7, which is implicated in homing to mucosal sites. Naive T cells (CD44(low), Thy1+) home to all secondary lymphoid organs. Alpha4beta7(high) memory-phenotype (CD44(high)) T cells home to Peyer's patches as efficiently as naive lymphocytes, whereas alpha4beta7- memory-phenotype T cells are essentially excluded from entry into these mucosal lymphoid organs. In contrast, alpha4beta7- memory-phenotype cells home approximately twice as efficiently as alpha4beta7(high) T cells to peripheral lymph nodes, but only approximately 20% as well as naive T cells. Interestingly, the spleen recruits all three identified subsets with nearly equal efficiency. The relative subset localization is similar 2.5 h after injection and after overnight trafficking, suggesting that memory cells can directly extravasate from blood into Peyer's Patches and lymph nodes. We conclude that subsets of memory T cells defined by patterns of homing receptor expression display differential homing to organized lymphoid tissues, an ability that may facilitate homeostatic interactions and target contributions to specialized regional immune responses.
Self gamma2a(b) protein is presented in vivo by gamma2a(b) B cells but not by dendritic cells.
Authors: Granucci F , Foti M , Cossarizza A , Ricciardi-Castagnoli P 
Published: January 2023

Abstract
We have previously shown that IgG2a(b) Ig does not induce tolerance in MHC class II restricted CD4 T cells in a TCR transgenic model and that anti-IgG2a(b) transgenic T cells specific for peptide 435-451 are indeed present in the periphery where they interact with gamma2a(b)-positive B cells. We also observed that because T cell tolerance depends on the presentation of self peptides, it was probable that IgG2a(b) was not easily processed and presented in vivo. In this study, we have investigated the presentation of naturally processed gamma2a(b) (435-451) determinants to specific T cells. Dendritic cells, macrophages, and B cells were purified from the spleens of Igh-1b mice. These cells were then functionally tested for the presence of specific peptide-MHC complexes. The results showed that, in vivo, gamma2a(b)-producing B cells, but not dendritic cells, are the only APCs able to present this self peptide. This indicates that recognition of the IgG2a(b)-self peptide is exclusively mediated by T-B cell interaction.
Congenic mapping of the insulin-dependent diabetes (Idd) gene, Idd10, localizes two genes mediating the Idd10 effect and eliminates the candidate Fcgr1.
Authors: Podolin P L , Denny P , Lord C J , Hill N J , Todd J A , Peterson L B , Wicker L S , Lyons P A 
Published: January 2023

Abstract
The development of autoimmune diabetes in the nonobese diabetic (NOD) mouse is under the control of multiple insulin-dependent diabetes (Idd) genes. The Idd3 gene, originally defined as a broad peak of linkage on mouse chromosome 3, was subsequently identified as two genes, Idd3 and Idd10, separated by at least 20 cM. The resistance alleles of Idd3 and Idd10 individually confer only partial protection from diabetes but, in combination, result in profound resistance to disease due to an epistatic genetic interaction. In this study, we used newly developed congenic strains to further localize Idd10. Surprisingly, we found that Idd10 itself comprises at least two linked loci: Idd10 and the newly designated Idd17. Idd17 was localized to a 1.1-cM region between D3Mit26 and D3Mit40, proximal to Fcgr1, a candidate gene encoding the high affinity Fc receptor for IgG. Idd10 was localized to a 10-cM region between D3Mit213 and D3Mit106, distal to Fcgr1. Thus, Fcgr1 was excluded as a candidate for either Idd10 or Idd17, despite the fact that the NOD strain expresses a mutant form of the receptor. Interestingly, although Idd10 and Idd17 participate in a genetic interaction with each other, Idd10 but not Idd17 participates in the genetic interaction with Idd3. Our study on chromosome 3 begins to reveal the extent of the polygenic nature of autoimmune diabetes, and demonstrates that the use of congenic strains is an effective mapping strategy, even in the dissection of multiple, linked genes with subtle effects.