bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and functional characterization of fowlicidin-1, a cationic host defense peptide with potent antibacterial and LPS-neutralizing activities (52.13)
Authors: Alexander Justin R , Bommineni Yugendar , Xiao Yanjing , Dai Huaien , Prakash Om , Zhang Guolong 
Published: January 2023

Abstract
Cathelicidins are a group of cationic host defense peptides with pluripotent immunomodulatory activities. We recently identified fowlicidin-1, a chicken cathelicidin possessing broad-spectrum antibacterial and LPS-neutralizing activities but with considerable toxicity toward mammalian cells. NMR spectroscopy revealed that fowlicidin-1 mainly adopts an α-helical conformation with glycine-induced kink in the center and a short flexible unstructured region at the N-terminal end. To reveal functional significance of different structural regions and identify peptide analog(s) with enhanced therapeutic potential, a series of deletion and substitution analogs of fowlicidin -1 were synthesized. Eight amino acids (residues 16–23) at the C-terminal end were found to be critically involved in bacterial killing, LPS binding and cytotoxicity. We also revealed that the N-terminal unstructured segment (residues 1–5) plays a minimum role in antibacterial and LPS-neutralizing activities. Removal of valine at position 5 reduced the cytotoxicity by 4-fold while retaining a similar antibacterial potency to the parent peptide. However, omission of tryptophan at position 6 resulted in at least 4-fold reduction in bacteria-killing efficiency, indicating the critical involvement of tryptophan. Taken together, fowlicidin-1(6–26) represents a short peptide analog with excellent potential to be explored as a novel antimicrobial.
This project was supported by Oklahoma Center for the Advancement of Science and Technology, Oklahoma Agricultural Experiment Station and HHMI-Undergraduate Research Scholarship.
Impaired expression of Toll-like receptors in peripheral blood monocytes and granulocytes in type 2 diabetic subjects (52.15)
Authors: MORENO-FIERROS LETICIA , Martinez-Barrera Luis Enrique 
Published: January 2023

Abstract
Type 2 diabetes represents a prevalent serious health problem worldwide. Type 2 diabetes (non-insulin-dependent) is characterized by chronic hyperglycemia and disturbances of carbohydrate, fat and protein metabolism. Complications among diabetic patients include increased recurrence and severity to many infections. Low-grade inflammation also seems to be involved in the pathogenesis of diabetes. However the underlying mechanisms of the immunological impairment in diabetes are unclear. Toll-like receptors (TLRs) play a key role in pathogen recognition by the innate immunity, interestingly altered TLR expression has been recently reported in diabetic rodent models but it has never been studied in humans. Therefore using flow cytometry we tested if, under basal conditions, TLR expression was altered in peripheral blood monocytes and granulocytes from Type 2 diabetic Mexican subjects. We found a decreased frequency of monocytes and granulocyte expressing TLR3 and TLR4 in diabetic subjects, nevertheless TLR2 and TLR9 expression was not significantly different between diabetic and healthy groups. Whereas in hyperglycemic conditions lower frequencies of TLR2, TLR3 and TLR4 expression were found, TLR9 expression was significantly higher. Our findings support that the increased incidence of infections occurring in diabetes maybe related an impaired TLR expression.
4-1BB stimulation induces pregnancy failure that is mediated by CD8+ T cells (52.16)
Authors: Kim Kwang H , Kim Young H , Lee Myeong J , Choi Beom K , Kim Jung D , Kwon Byoung S 
Published: January 2023

Abstract
4-1BB (CD137) regarded as a powerful T-cell costimulatory molecule. However, recent studies indicate that in vivo 4-1BB stimulation is able to actively suppress the antigen-specific immune response by inducing indoleamine 2,3-dioxygenase (IDO) in antigen-presenting cells. Since we found that both 4-1BB and IDO were induced in the placenta during pregnancy, we questioned whether 4-1BB signaling would be negative or positive on the pregnancy. By treating agonistic anti-4-1BB mAb or blocking anti-4-1BBL mAb to the pregnant mice, we tested the role of 4-1BB. Treatment of agonistic anti-4-1BB mAb markedly increased the abortion of allogeneic fetus, which was primarily dependent on the CD8+ T cells. Since anti-4-1BB treatment induced the accumulation of C3 component in the placenta, which was reversed by treating depleting anti-CD8 mAb, C3 complement seemed to be functioned as an effector molecule in the placenta. However, blockade of 4-1BB / 4-1BBL interaction or 4-1BB stimulation to the syngeneic fetus showed a marginal effect on the pregnancy. These results indicate that 4-1BB signal may be involved in the regulation of immune responses between maternal T cells and fetal tissues.
This study was supported by the Science Research Center Fund from KOSEF and the Korean Ministry of Science and Technology.
ASP-C5L2 neutralizing antibodies alter triglyceride metabolism in vitro and in vivo (53.10)
Authors: Cianflone Katherine , Cui Wei , Paglialunga Sabina , Kalant David , Lu HuiLing , Roy Christian 
Published: January 2023

Abstract
There are growing data that show the linkage between immune and metabolic systems. C3a is an anaphylatoxin. Its inactive product, C3a desArg, known as Acylation Stimulating Protein (ASP), is well documented as a lipogenic factor stimulating triglyceride synthesis (TGS) and glucose transport (GT). Recently, C5L2 was identified as a functional receptor of ASP. Interestingly, C5a also binds C5L2, but binding has no inflammatory response, suggesting C5L2 is a C5a decoy receptor. The aim of this study is to determine in vitro and in vivo effects of blocking ASP-C5L2 interaction using antiASP and antiC5L2 IgG. In C5L2 transfected HEK cells, antiASP or antiC5L2 competes for ASP binding (IC50: ASP 93±27 nM; antiC5L2, 199±19 nM;) and inhibit TGS and GT. In mice, antibody injection had no effect on body and tissue weight, food intake, and plasma levels of insulin, leptin, or adiponectin, but caused delayed TG (AUC: control 2.0±0.3 mM*5 h; antiASP 11.8±1.5 mM*5h p&lt;0.001; antiC5L2 10.4±0.9 mM*5h, p&lt;0.001) and non-esterified fatty acid (AUC: control 1.3±0.3 mM*5h; antiASP 7.2±0.5 mM*5h p&lt;0.001; antiC5L2 6.9±0.3 mM*5h p&lt;0.001) clearance. TG content decreased in liver (antiASP -28.0% p&lt;0.05; anti-C5L2 −40.9% p&lt;0.01), but increased in muscle (62.0%, antiASP, p&lt;0.01; 81.4%, antiC5L2, p&lt;0.001). AntiASP and antiC5L2 block ASP-C5L2 interaction, demonstrating ASP functions through C5L2 receptor.
Funding: CIHR
Complement-mediated hemolytic anemia and platelet activation in mCd59a and mCd59b double knockout mice (53.4)
Authors: Qin Xuebin , Hu Weiguo , Song Wenping , Grubissich Luciano , Song Yanli , Wu Gongxiong , Hu Xuemei , Ferris Sean , Dobarro Martin , Bauer Selena , Feelisch Martin , Leopold Jane A. , Loscalzo Joseph , Halperin Jose A 
Published: January 2023

Abstract
The complement regulatory protein CD59 inhibits formation of the complement membrane attack complex (MAC). Humans express only one while mice express two Cd59 genes; each mCd59 gene contains two promoters that control its expression in a tissue specific manner. Thus, total deficiency of mCd59 activity is required to study unambiguously the role of MAC and CD59 in mouse models of human diseases including paroxysmal nocturnal hemoglobinuria (PNH), a complement mediated hemolytic anemia with thrombosis due to the lack of GPI-linked membrane proteins, especially CD59. Here we report the targeted deletion of both mCd59 genes in mCd59ab−/− mice, their PNH-like phenotype, and the use of these mice in complement sufficient and complement (C3) deficient background to establish the role of complement in the activation of PNH-like platelets in vivo. Low NO bioavailability in the vasculature due to increased NO-scavenging free hemoglobin in their blood has long been suspected to contribute to the thrombotic diathesis and smooth muscle dystonias of PNH-patients. Using an NO-synthase inhibitor in vivo and an NO donor in vitro, we established a novel balancing effect of nitric oxide (NO) in the complement-mediated activation of mCd59ab−/− (CD59 deficient, PNH-like). These results unmask a hitherto unrecognized role for NO in balancing complement-mediated platelet activation.
C-Reactive Protein Stimulated Spleen Cells Transfer Suppression of Experimental Immune Thrombocytopenia (53.9)
Authors: Marjon Kristopher David , Clos Terry W Du , Marnell Lorraine L , Verbeek J. Sjef , Mold Carolyn 
Published: January 2023

Abstract
C-reactive protein (CRP) is an innate recognition molecule, which regulates immune responses by interaction with FcγR. CRP suppresses inflammation and autoimmunity in diverse experimental models. Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease in which platelets are cleared by splenic macrophages through FcγR. IVIG is used to treat human ITP. IVIG induces dendritic cells to transfer suppression of ITP (Siragam et al., 2006, Nat Med). In this study, splenocytes were treated with 200 μg/ml CRP or BSA or 1.8 mg/ml IVIG for 30 min, washed and transferred to naïve recipients. After 24 h, ITP was induced by injection of anti-CD41 mAb. Platelets were counted 24 h later. Anti-CD41 decreased platelet counts from 945±29 to 312±61 x 103/mm3. Platelet counts in recipients of 106 treated spleen cells were: BSA, 225±35; CRP, 672±25; and IVIG 590±35. Spleen cells from FcR γ-chain−/− or FcγRI−/− mice treated with CRP or IVIG were not protective and no protection was observed in FcγRIIb−/− mice. Macrophage depletion in vivo by Clodronate liposome treatment of the donor eliminated protection by CRP (363±9, p&lt;0.001 vs CRP), but not IVIG (560±38). Thus, CRP treatment of spleen cells in vitro generates a cell that transfers suppression of ITP. Generation of this cell by CRP is dependent on FcγRI and macrophages. The findings allow for the characterization of the cells involved in the immunoregulatory properties of CRP.
RNA-Binding Protein Pum2 Promotes Self-renewal and Suppresses Differentiation of Multipotent Hematopoietic Cells by Maintaining Them in Inactive CD34− State (81.3)
Authors: Zayas Jennifer , Nachtman Ronald G , George John , Jurecic Roland 
Published: January 2023

Abstract
Over-expression of RNA-binding protein Pum2 supports maintenance and suppresses mutilineage differentiation of murine HSC-like cell line EML. Analysis of HSC markers on wild type EML cells and EML cells over-expressing Pum2 (Pum2-EML cells) has revealed that almost all wt EML cells are Sca-1+c-kit+ Flk2−, but exhibit heterogeneous expression of CD34, with ~20% of cells being CD34−, and ~80% being CD34+. Similarly, almost all Pum2-EML cells are Sca-1+c-kit+Flk2−, but the vast majority of Pum2-EML cells are CD34− (80–95%). Functional analysis has revealed that purified CD34+ subpopulation of wt EML and Pum2-EML cells repeatedly contained almost all of the cells capable of mutilineage differentiation in response to cytokines. In contrast, the CD34− subpopulations of wt EML and Pum2-EML cells differentiated poorly or not at all. Previous studies have shown that mouse HSC can alternate between “activated” CD34+ and CD34− “inactive” state. Thus, we testedwhether CD34− EML cells are more primitive and give rise to CD34+ cells, orwhether EML cells alternate between CD34− inactive (differentiation inhibited) and CD34+ active (differentiation ready) state.
Culture and flow cytometry analysis of purified CD34− and CD34+ wt EML cells has revealed that both CD34− and CD34+ EML cells reproducibly generate each other, and that the “secondary” CD34− and CD34+ EML cells exhibit the same properties. Identical experiments have revealed that Pum2-EML cells are maintained predominantly in an inactive CD34-state. These results support the notion that Pum2 protein supports proliferation and suppresses differentiation (two critical components of self-renewal) of multipotent hematopoietic cells by maintaining them in inactive CD34− state.
Multiple prethymic defects underlie age-related loss of T progenitor competence (81.6)
Authors: Zediak Valerie P. , Maillard Ivan , Bhandoola Avinash 
Published: January 2023

Abstract
Aging in mice and humans is characterized by declining T lymphocyte production in the thymus, yet it is unclear whether aging impacts the T lineage potential of hematopoietic progenitors. Although alterations in the lymphoid progenitor content of aged mouse bone marrow have recently been described, irradiation- reconstitution experiments have failed to reveal defects in T lineage potential of bone marrow (BM) progenitors or purified hematopoietic stem cells (HSC) from aged mice. Here, we assessed T progenitor potential in young recipient mice without conditioning irradiation. T potential was reduced in aged BM compared to young BM and this reduction was apparent at the earliest stages of intrathymic differentiation. Further, purified populations of aged HSC or multipotent progenitors (MPP) also gave rise to fewer T lineage cells than their young counterparts. Limiting dilution experiments in vitro showed that the T precursor frequency within the MPP pool was unchanged. However, there was a fourfold reduction in T precursor frequency within the aged HSC pool, indicating that there is an accumulation of T-incompetent cells in this population. Additionally, among the T-competent HSC clones, there were fewer highly proliferative clones in the aged HSC pool than in the young HSC pool. These results define the nature and cellular sites of prethymic age-related defects in T lineage differentiation potential.
The Jackson Laboratory repository: model selection for immunology research (82.10)
Authors: Lake Jeffrey , Donahue Leah Rae , Lutz Cathy , Rockwood Stephan , Sasner Michael 
Published: January 2023

Abstract
The mouse continues as one of the most important model organisms. The Jackson Laboratory Repository serves as a centralized facility for developing, rederiving, cryopreserving and distributing mouse models. The Repository contains a large repertoire of mouse strains related to immunology research that have applications in studies of basic immunology, innate immunity, cancer research, autoimmunity, allergic diseases, and infectious diseases.
Selecting appropriate mutant mice is often difficult. For example, mice devoid of CD4+ T cells are found in 3 different strains including a Cd4 −/− strain (B6.129S2-Cd4tm1Mak/J), a strain where MHC class II genes were deleted (B6.129-H2dlAb1-Ea/J), or a targeted mutation in the class II transactivator (B6.129S2-C2tatm1Ccum/J). A wide variety of cre-expressing strains, targeted mutants with loxP-flanked genes and tetracycline regulated transactivator-expressing mice are available that require careful selection. Other factors for model selection include mutation characteristics related to mechanism of action, cell types affected, effects of the mutation on breeding and lifespan, and other associated phenotypes. The strain background including breeding performance, MHC haplotype, disease resistance/susceptibilility and known mutations, such as hemolytic complement deficiency found in a subset of inbred strains, could confound results.
Supported by NCRR (RR09781, RR11083, RR16049), NIA, HHMI, and donations from several private foundations
Development of all CD4 T lineages requires nuclear factor TOX (82.2)
Authors: Aliahmad Parinaz , Kaye Jonathan 
Published: January 2023

Abstract
We have previously identified a nuclear factor member of the HMG-box superfamily, designated TOX, which is transiently expressed in the thymus during both positive selection and β-selection. We had shown that Tox is upregulated by calcineurin-dependent signaling and transgenic mice that express TOX generate CD8 single positive thymocytes (CD8SP), even in the absence of TCR signaling. We now report that mice deficient in TOX (TOX−/−) are outwardly normal but lack all CD4 lineage cells, namely CD4 αβ T, CD4 regulatory T and NK-T cells, due to a block in positive selection at the transitional CD4loCD8lo stage. In contrast, some CD8SP thymocytes develop in TOX−/− mice. These CD8SP can colonize the periphery and respond to TCR triggering. The block in CD4 T but not CD8 T cell development in TOX−/− mice is also observed in TCR transgenic animals. These results demonstrate differential requirements for the CD4 and CD8 lineages, where CD4-destined cells require induction of TOX for their development.
Negative selection of Th1-skewed NKT cells by the thymic epithelial CD1d (82.8)
Authors: Lee Hyunji , Hong Changwan , Park Se-Ho 
Published: January 2023

Abstract
NKT cells are a specialized subset of T cells mainly utilizing invariant Vα14-Jα18 chain for their T cell receptor. Unlike conventional T cells which are dependent on MHC class I or II, NKT cells are dependent on a MHC class I-like molecule, CD1d, for their development. Unlike MHC class I and II molecules, which support both of the positive and negative selection of conventional T cells, it was not clear whether CD1d also participate in negative selection of NKT cells. By comparing the NKT cell population and their characteristics in CD1d-deficient Vα14 transgenic mouse and CD1d-deficient Vα14/Eα-CD1d double transgenic mouse, we found that a subset of NKT cells with the phenotype of NK1.1+, CD44high, CD69high and showing Th1-skewed cytokine production was subjected to the negative selection by the CD1d expressed in thymic epithelial tissue. These results suggest that CD1d is critical not only for the positive selection of NKT cells, but also for the negative selection of NKT cells which have potentially harmful excessive self reactivity.
Thymic selection in the absence of TCR/coreceptor agreement (82.9)
Authors: Riddle David S , Frelinger Jeffrey , Collins Edward 
Published: January 2023

Abstract
The contribution of TCR coreceptor to T cell lineage commitment has not been firmly established. Models proposed to explain lineage commitment require that the MHC specificity of TCR and coreceptor agree in order for thymocytes to develop successfully. We have generated a mouse model, MHC II°/CD8°, in which TCR/coreceptor agreement cannot occur. This mouse has between one half and one third of the number of peripheral T cells compared to wild type mice, depending on age. Nonetheless, the T cells utilize an array of TCR variable genes similar to wild type, suggesting that the reduced number of peripheral T cells is not due to a bottleneck in the population of TCRs that can be positively selected in such a restrictive environment. Both CD4+ and coreceptor negative T cells produce IL-2 and IFNg in response to antigen-independent stimulation. Furthermore, despite the lack of CD8, peripheral coreceptor negative T cells display cytolytic function against allogeneic MHC, and against syngeneic MHC following LCMV infection. These results indicate that TCR/coreceptor agreement during thymic selection is not necessary for development of a heterogeneous population of functional T cells, and thus have implications for current models of lineage commitment.
Impaired pre-B cell development in the alpha 1,6-fucosyltransferase deficient mice (83.13)
Authors: Kondo Akihiro , Li Wenzhe , Ishihara Katsuhiko , Yokota Takafumi , Nakagawa Takatoshi , Miyoshi Eiji , Koyama Nobuto , Taniguchi Naoyuki 
Published: January 2023

Abstract
The alpha 1,6-fucosyltransferase (FUT8) is responsible for the core-fucosylation of N-glycans and core fucose of N-glycans could modify function of glycoproteins on the cell surface. Mice with a targeted gene disruption of Fut8 (Fut8−/−) had impaired B cell development at the pre-B cell stage, reduced numbers of immature B cells, reduced B cell proliferative responses and antibody production. Our finding for the first time showed impaired early B cells development owing to the low binding affinity of VLA-4 to VCAM-1 in Fut8-KD-pre-B cells. Consistently, reintroduction of Fut8 partly restored the binding affinity by an increase in the percentage of binding cells from 29% to 44%, indicating that core fucosylation is required for VLA-4/VCAM-1 interaction during B cell development. Loss of early B cell lineage was associated with down-regulation of several gene expressions, such as CD79a, CD79b, Ebf1, Tcfe2a in Fut8−/− CD45R+IgM− cells. Indeed, the ratio of pre-BCR+CD79b+ cells in gated Fut8−/− pre-B cells was much lower than in Fut8+/+ pre-B cells, indicating a differentiation defect in the transition from pro-B cell to pre-B cell. These results provide evidence that Fut8 is functionally linked to the VLA-4/VCAM-1 interaction in mediating B cell tethering to stromal cells and is pivotal in B cell development and activation.
Plasma cell differentiation and lipid metabolism (83.18)
Authors: Bommiasamy Hemamalini , Sriburi Rungtawan , Jackowski Suzanne , Brewer Joseph W. 
Published: January 2023

Abstract
Plasma cells are terminally differentiated B cells that produce and secrete profuse amounts of antibodies. Plasma cell differentiation involves an increase in exocytic pathway components and expansion of the endoplasmic reticulum (ER) in order to accommodate high-rate immunoglobulin synthesis. ER expansion requires membrane biogenesis, a process that requires phospholipids. Increased phospholipid synthesis is dependent upon a sufficient supply of fatty acids. We have found that de novo fatty acid biosynthesis increases in CH12 B cells differentiating in response to lipopolysaccharide (LPS). Increased fatty acid biosynthesis correlates with upregulation of acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS), enzymes that catalyze the formation of fatty acids. Further investigation will shed light into mechanisms that regulate lipid synthesis and ER expansion in differentiating plasma cells.
Supported by NIH-GM61970 and NIH-T32 A1007508
The beta-catenin pathway is involved in normal B cell development and function (83.3)
Authors: Ko Alex Y , Zierold-Fairman Claudia , Ranheim Erik A 
Published: January 2023

Abstract
Wnt/Fzd signaling plays a key role in development, stem cell maintenance, and tumorigenesis, particularly via stabilization of ß-catenin protein levels. TCF-1 and LEF-1 knockout mice suggested a role for this pathway in lymphoid development as well. We have previously shown that Fzd9−/− mice exhibit a decrease in pre-B cells at a stage when self-renewing division is occurring in preference over further differentiation, prior to light chain Ig recombination (Hardy C-D). We now report further evidence for a role of ß-catenin in normal B cell function and development. By flow cytometric analysis, we find that cellular ß-catenin levels rise at precisely the stage of B cell development that shows diminished numbers in Fzd9−/− mice. Expression of LEF-1, the transcriptional partner of ß-catenin, also is tightly regulated during this developmental sequence by differential transcription of full length and dominant negative forms, further suggesting that Wnt/Fzd signals impact on B-cell lymphopoiesis. In mature B-cells, activation through BCR, Toll-like receptors, and CD40 all induce an increase in beta-catenin protein levels, while changes in the expression of genes involved in both positive and negative regulation of canonical Wnt signaling are differentially regulated by these stimuli, highlighting a potential novel role for this pathway in B-lymphocyte proliferation, differentiation, and survival.