bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Synovial γδ T Cell Ligand Expression by Mitochondrial Reactive Oxygen Species and Gasdermin-D
Authors: Collins Cheryl C , Hahn Peter , Jiang Zhaozhao , Fitzgerald Katherine A , Xiao Tsan Sam , Budd Ralph C
Published: January 2023

γδ T cells reside at mucosal and epithelial barriers, and they often accumulate at sites of inflammation, both infectious and autoimmune, as well as in certain tumors. However, progress in understanding their function is considerably hampered by a lack of full understanding of the ligands recognized by TCR-γδ and how expression of these ligands is regulated. We recently developed a soluble human TCR-γδ (Vγ9Vδ1) tetramer from a synovial γδ T cell clone of a Lyme arthritis patient and observed that it stains monocytes activated by Borrelia burgdorferi. Those findings are extended in the current study to further examine the physiological regulation of ligand expression on monocytes. The TCR-γδ ligand is induced by a variety of TLR agonists and requires NF-κB activation. Of particular interest is that ligand expression also requires caspase activation of the inflammasome and is dependent on active metabolism, mitochondrial reactive oxygen species, and activation of gasdermin-D. Consistent with these observations, the TCR-γδ ligand is expressed by a subset of metabolically active CD14+CD16+ monocytes and colocalizes intracellularly with mitochondria. The findings suggest a model in which synovial γδ T cell ligand is a self-antigen whose surface expression is increased by inflammatory conditions and mitochondrial stress.
Clinical Correlation of Function and TCR vβ Diversity of MAGE-C2–Specific CD8+ T Cell Response in Esophageal Cancer
Authors: Li Pupu , Chen Xinfeng , Ping Yu , Qin Guohui , Huang Lan , Zhao Qitai , Zhang Zhen , Chen Huanan , Wang Liping , Yang Shengli , Zhang Yi
Published: January 2023

Melanoma-associated Ag (MAGE)-C2, an immunogenic cancer germline (testis) Ag, is highly expressed by various tumor cells, thymic medullary epithelial cells, and germ cells. In this study, we aimed to explore the immunologic properties of MAGE-C2–specific CD8+ T cells and the relationship of its TCR β-chain V region (TCR vβ) subfamily distribution to prognosis of patients with esophageal cancer. PBMCs and tumor-infiltrating lymphocytes expanded by CD3/CD28 Dynabeads and MAGE-C2 peptides in vitro resulted in the induction of lysosome-associated membrane protein-1 (LAMP-1 or CD107a) on the cell surface and the production of IFN-γ by MAGE-C2–specific CD8+ T cells. We found differential TCR vβ subfamily distribution among flow-sorted CD107a+IFN-γ+ and CD107a−IFN-γ− CD8+ T cells. The proportion of CD107a+ and/or IFN-γ+ tetramer+ CD8+ T cells was lower in patients with lymph node metastasis, late tumor stage, and poorly differentiated state (p < 0.05). T-box transcription factor was positively correlated with CD107a and IFN-γ. Kaplan–Meier analysis showed that patients whose MAGE-C2–specific CD8+ T cells expressed high CD107a and/or IFN-γ had a longer survival time when compared with patients whose MAGE-C2–specific CD8+ T cells expressed low levels of CD107a and/or IFN-γ. Moreover, analysis of TCR vβ subfamily distribution revealed that a higher frequency of TCR vβ16 in MAGE-C2–specific CD8+ T cells was positively correlated with a better prognosis. These results suggest that the presence of functional MAGE-C2–specific CD8+ T cells had an independent prognostic impact on the survival of patients with esophageal cancer.
β-Glucosylceramides and Tocopherols Regulate Development and Function of Dendritic Cells
Authors: Lajiness Jacquelyn D , Amarsaikhan Nansalmaa , Tat Kiet , Tsoggerel Angar , Cook-Mills Joan M
Published: January 2023

In humans and mice, offspring of allergic mothers are predisposed to development of allergy. In mice, allergic mothers have elevated β-glucosylceramides (βGlcCers) that are transported to the fetus via the placenta and to offspring via milk. The elevated βGlcCers increase the number of fetal liver CD11c+CD11b+ dendritic cells (DCs) and offspring allergen-induced lung eosinophilia. These effects are modifiable by maternal dietary supplementation with the plant-derived lipids α-tocopherol and γ-tocopherol. It is not known whether βGlcCers and tocopherols directly regulate development of DCs. In this study, we demonstrated that βGlcCers increased development of GM-CSF–stimulated mouse bone marrow–derived DCs (BMDCs) in vitro without altering expression of costimulatory molecules. This increase in BMDC numbers was blocked by α-tocopherol and potentiated by γ-tocopherol. Furthermore, βGlcCers increased protein kinase Cα (PKCα) and PKCδ activation in BMDCs that was blocked by α-tocopherol. In contrast, γ-tocopherol increased BMDC PKCα and PKCδ activation and enhanced the βGlcCer-induced increase in PKCδ activation in a DC subset. Ag processing per DC was minimally enhanced in βGlcCer-treated BMDCs and not altered ex vivo in lung DCs from pups of allergic mothers. Pups of allergic mothers had an increased proportion of CD11b+CD11c+ subsets of DCs, contributing to enhanced stimulation of T cell proliferation ex vivo. Thus, βGlcCer, which is both necessary and sufficient for development of allergic predisposition in offspring of allergic mothers, directly increased development and PKC activation in BMDCs. Furthermore, this was modifiable by dietary tocopherols. This may inform design of future studies for the prevention or intervention in asthma and allergic disease.
BCR-Associated Protein 31 Regulates Macrophages Polarization and Wound Healing Function via Early Growth Response 2/C/EBPβ and IL-4Rα/C/EBPβ Pathways
Authors: Yuan Qing , Zhao Bo , Cao Yu-hua , Yan Jia-cheng , Sun Li-jun , Liu Xia , Xu Yang , Wang Xiao-yu , Wang Bing
Published: January 2023

The BCR-associated protein 31 (BAP31), a transmembrane protein in the endoplasmic reticulum, participates in the regulation of immune cells, such as microglia and T cells, and has potential functions in macrophages that remain to be unexplored. In this study, we designed and bred macrophage-specific BAP31 knockdown mice to detect the polarization and functions of macrophages. The results revealed that M2 macrophage-associated genes were suppressed in mouse bone marrow–derived macrophages of Lyz2 Cre-BAP31flox/flox mice. Multiple macrophage-associated transcription factors were demonstrated to be able to be regulated by BAP31. Among these factors, C/EBPβ was the most significantly decreased and was regulated by early growth response 2. BAP31 could also affect C/EBPβ via modulating IL-4Rα ubiquitination and proteasome degradation in IL-4–stimulated macrophages. Furthermore, we found that BAP31 affects macrophages functions, including angiogenesis and skin fibrosis, during the wound healing process through IL-4Rα, as confirmed by infection with adeno-associated virus–short hairpin (sh)-IL-4Rα in Lyz2 Cre-BAP31flox/flox mice. Our findings indicate a novel mechanism of BAP31 in regulating macrophages and provide potential solutions for the prevention and treatment of chronic wounds.
Deacetylation of K481 and K484 on Penaeid Shrimp Hemocyanin Is Critical for Antibacterial Activity
Authors: Nie Junjie , Aweya Jude Juventus , Yu Zhixue , Zhou Hui , Wang Fan , Yao Defu , Zheng Zhihong , Li Shengkang , Ma Hongyu , Zhang Yueling
Published: January 2023

Although invertebrates’ innate immunity relies on several immune-like molecules, the diversity of these molecules and their immune response mechanisms are not well understood. Here, we show that Penaeus vannamei hemocyanin (PvHMC) undergoes specific deacetylation under Vibrio parahaemolyticus and LPS challenge. In vitro deacetylation of PvHMC increases its binding capacity with LPS and antibacterial activity against Gram-negative bacteria. Lysine residues K481 and K484 on the Ig-like domain of PvHMC are the main acetylation sites modulated by the acetyltransferase TIP60 and deacetylase HDAC3. Deacetylation of PvHMC on K481 and K484 allows PvHMC to form a positively charged binding pocket that interacts directly with LPS, whereas acetylation abrogates the positive charge to decrease PvHMC–LPS attraction. Besides, V. parahaemolyticus and LPS challenge increases the expression of Pvhdac3 to induce PvHMC deacetylation. This work indicates that, during bacterial infections, deacetylation of hemocyanin is crucial for binding with LPS to clear Gram-negative bacteria in crustaceans.
SpRab11a-Regulated Exosomes Inhibit Bacterial Infection through the Activation of Antilipopolysaccharide Factors in Crustaceans
Authors: Sun Qian , Lin Shanmeng , Zhang Ming , Gong Yi , Ma Hongyu , Tran Ngoc Tuan , Zhang Yueling , Li Shengkang
Published: January 2023

Exosomes, secreted by most cells, are critical antimicrobial immune factors in animals. Recent studies of certain key regulators of vesicular transport, the Rab GTPases, have linked Rab dysfunction to regulation of innate immune signaling. However, the relationship between exosomes and Rab GTPases, resulting in antimicrobial activity in vertebrates and invertebrates during pathogenic infection, has not been addressed. In this study, SpRab11a was reported to have a protective effect on the survival rate of mud crabs Scylla paramamosain after Vibrio parahaemolyticus challenge through the stimulation of exosome secretion and modulation of anti-LPS factor (ALF) expression. Furthermore, Sp14-3-3 was confirmed to be densely packaged in exosomes after V. parahaemolyticus infection, which could recruit the MyD88 and TLR by binding the Toll/IL-1R domain to the plasma membrane, promoting the translocation of Dorsal from the cytoplasm into the nucleus, and thereby regulating ALFs expression in the hemocytes of mud crab in response to the bacterial infection. The findings therefore provide, to our knowledge, a novel mechanism that underlies the cross-talk between SpRab11a-regulated exosome formation and ALFs expression in innate immune response in invertebrates, with a crustacean species, mud crab S. paramamosain, as a model study.
Differential Roles for IL-1α and IL-1β in Pseudomonas aeruginosa Corneal Infection
Authors: Ratitong Bridget , Marshall Michaela E , Dragan Morgan A , Anunciado Charissa M , Abbondante Serena , Pearlman Eric
Published: January 2023

Pseudomonas aeruginosa is an important cause of dermal, pulmonary, and ocular disease. Our studies have focused on P. aeruginosa infections of the cornea (keratitis) as a major cause of blinding microbial infections. The infection leads to an influx of innate immune cells, with neutrophils making up to 90% of recruited cells during early stages. We previously reported that the proinflammatory cytokines IL-1α and IL-1β were elevated during infection. Compared with wild-type (WT), infected Il1b−/− mice developed more severe corneal disease that is associated with impaired bacterial killing as a result of defective neutrophil recruitment. We also reported that neutrophils are an important source of IL-1α and IL-1β, which peaked at 24 h postinfection. To examine the role of IL-1α compared with IL-1β in P. aeruginosa keratitis, we inoculated corneas of C57BL/6 (WT), Il1a−/−, Il1b−/−, and Il1a−/−Il1b−/− (double-knockout) mice with 5 × 104 ExoS-expressing P. aeruginosa. Il1b−/− and double-knockout mice have significantly higher bacterial burden that was consistent with delayed neutrophil and monocyte recruitment to the corneas. Surprisingly, Il1a−/− mice had the opposite phenotype with enhanced bacteria clearance compared with WT mice. Although there were no significant differences in neutrophil recruitment, Il1a−/− neutrophils displayed a more proinflammatory transcriptomic profile compared to WT with elevations in C1q expression that likely caused the phenotypic differences observed. To our knowledge, our findings identify a novel, non-redundant role for IL-1α in impairing bacterial clearance.
Nucleic Acid Sensing and Systemic Lupus Erythematosus: The Danger of Self
Authors: Zou Yong-Rui , Davidson Anne
Published: January 2023

This Pillars of Immunology article is a commentary on “Chromatin–IgG complexes activate B cells by dual engagement of IgM and Toll-like receptors,” a pivotal article written by E. A. Leadbetter, I. R. Rifkin, A. M. Hohlbaum, B. C. Beaudette, M. J. Shlomchik and A. Marshak-Rothstein, and published in Nature in 2002. https://www.nature.com/articles/416603a.
Structurally Altered, Not Wild-Type, Pentameric C-Reactive Protein Inhibits Formation of Amyloid-β Fibrils
Authors: Ngwa Donald N , Agrawal Alok
Published: January 2023

The structure of wild-type pentameric C-reactive protein (CRP) is stabilized by two calcium ions that are required for the binding of CRP to its ligand phosphocholine. CRP in its structurally altered pentameric conformations also binds to proteins that are denatured and aggregated by immobilization on microtiter plates; however, the identity of the ligand on immobilized proteins remains unknown. We tested the hypotheses that immobilization of proteins generated an amyloid-like structure and that amyloid-like structure was the ligand for structurally altered pentameric CRP. We found that the Abs to amyloid-β peptide 1–42 (Aβ) reacted with immobilized proteins, indicating that some immobilized proteins express an Aβ epitope. Accordingly, four different CRP mutants capable of binding to immobilized proteins were constructed, and their binding to fluid-phase Aβ was determined. All CRP mutants bound to fluid-phase Aβ, suggesting that Aβ is a ligand for structurally altered pentameric CRP. In addition, the interaction between CRP mutants and Aβ prevented the formation of Aβ fibrils. The growth of Aβ fibrils was also halted when CRP mutants were added to growing fibrils. Biochemical analyses of CRP mutants revealed altered topology of the Ca2+-binding site, suggesting a role of this region of CRP in binding to Aβ. Combined with previous reports that structurally altered pentameric CRP is generated in vivo, we conclude that CRP is a dual pattern recognition molecule and an antiamyloidogenic protein. These findings have implications for Alzheimer’s and other neurodegenerative diseases caused by amyloidosis and for the diseases caused by the deposition of otherwise fluid-phase proteins.
Single-Cell Analysis Reveals the Range of Transcriptional States of Circulating Human Neutrophils
Authors: Wigerblad Gustaf , Cao Qilin , Brooks Stephen , Naz Faiza , Gadkari Manasi , Jiang Kan , Gupta Sarthak , O’Neil Liam , Dell’Orso Stefania , Kaplan Mariana J , Franco Luis M
Published: January 2023

Neutrophils are the most abundant leukocytes in human blood and are essential components of innate immunity. Until recently, neutrophils were considered homogeneous and transcriptionally inactive cells, but both concepts are being challenged. Single-cell RNA sequencing (scRNA-seq) offers an unbiased view of cells along a continuum of transcriptional states. However, the use of scRNA-seq to characterize neutrophils has proven technically difficult, explaining in part the paucity of published single-cell data on neutrophils. We have found that modifications to the data analysis pipeline, rather than to the existing scRNA-seq chemistries, can significantly increase the detection of human neutrophils in scRNA-seq. We have then applied a modified pipeline to the study of human peripheral blood neutrophils. Our findings indicate that circulating human neutrophils are transcriptionally heterogeneous cells, which can be classified into one of four transcriptional clusters that are reproducible among healthy human subjects. We demonstrate that peripheral blood neutrophils shift from relatively immature (Nh0) cells, through a transitional phenotype (Nh1), into one of two end points defined by either relative transcriptional inactivity (Nh2) or high expression of type I IFN-inducible genes (Nh3). Transitions among states are characterized by the expression of specific transcription factors. By simultaneously measuring surface proteins and intracellular transcripts at the single-cell level, we show that these transcriptional subsets are independent of the canonical surface proteins that are commonly used to define and characterize human neutrophils. These findings provide a new view of human neutrophil heterogeneity, with potential implications for the characterization of neutrophils in health and disease.
Follicular CD8+ T Cells Are Elevated in HIV Infection and Induce PD-L1 on B Cells
Authors: Martínez Laura E , Ibarrondo Javier , Guo Yu , Penichet Manuel L , Epeldegui Marta
Published: January 2023

Follicular CD8+CXCR5+ T cells are a specialized CD8+ T cell subset with unique follicular-homing capabilities that have been reported to display effector functions in viral immunity, tumor immunity, and autoimmunity. CD8+CXCR5+ T cells exhibit B cell helper functions and express CD40L, ICOS, programmed cell death protein 1 (PD-1), and BCL-6, the transcriptional regulator of CD4+CXCR5+ T follicular helper cells and of germinal center B cells. HIV is known to be sequestered in lymphoid follicles, and CD8+CXCR5+ T cell frequency is a marker for disease severity, given that HIV-infected patients with lower numbers of circulating CD8+CXCR5+ T cells display lower CD4+ T cell counts. Likewise, several groups have reported a direct correlation between the quantity of CD8+CXCR5+ T cells and suppression of HIV viral load. In this study, we observed elevated absolute numbers of CD8+CXCR5+ and CD8+CXCR5+BCL-6+PD-1+ T cells in the blood of HIV-infected participants of the Multicenter AIDS Cohort Study. We further demonstrated in vitro that activated human CD8+CXCR5+ T cells isolated from peripheral blood and tonsil from healthy donors show increased CD40L expression and induce the production of PD ligand 1 (PD-L1)+IgG+ B cells. Moreover, absolute numbers of CD8+CXCR5+ T cells significantly and positively correlated with numbers of PD-L1+ B cells found in blood of HIV-infected individuals. Altogether, these results show that activated CD8+CXCR5+ T cells have the ability to activate B cells and increase the percentage of PD-L1+ and PD-L1+IgG+ B cells, which provides insights into the early events of B cell activation and differentiation and may play a role in disease progression and lymphomagenesis in HIV-infected individuals.
Generation of a Large Repertoire of Monoclonal Antibodies against Dengue Virus NS1 Antigen and the Development of a Novel NS1 Detection Enzyme-Linked Immunosorbent Assay
Authors: Mehdi Farha , Chowdhury Shirlie Roy , Yadav Sarla , Kansana Jitendra Singh , Sinha Sangita Kumari , Das Soon Jyoti , Lodha Rakesh , Prakash John Antony Jude , Lamminimäki Urpo , Batra Gaurav
Published: January 2023

Commercial dengue virus (DENV) nonstructural-1 (NS1) Ag detection immunoassays often perform poorly, particularly in secondary DENV infection. To develop a highly sensitive NS1 ELISA, we generated a large repertoire of anti-DENV NS1 mouse mAbs (n = 95) that falls into 36 mAb classes based on binding specificities. The identified mAb pair, capable of efficiently detecting NS1 from four DENV serotypes in an immunoassay, was selected based on multiparametric analysis. The selected mAbs have subnanomolar affinities for NS1 with recognition sites outside the immunodominant wing domain. The assay was converted to an ELISA kit, which showed higher analytical sensitivity (3-fold to 83-fold) for NS1 from four DENV serotypes than commercial Platelia NS1 ELISA (Bio-Rad Laboratories). Compared to RT-PCR, the developed NS1 ELISA showed 78.57% (66 of 84) sensitivity, whereas Platelia NS1 ELISA showed a sensitivity of 60.71% (51 of 84). In a subgroup of RT-PCR–positive secondary dengue samples, our ELISA showed a sensitivity of 70.18% (40 of 57), whereas Platelia ELISA detected only 47.37% (27 of 57) samples. Furthermore, unlike Platelia ELISA, our test equally detected NS1 from four serotypes; Platelia ELISA performed poorly for the DENV-2 serotype, in which only 8 of 21 (38.10%) samples were detected compared with 17 of 21 (80.95%) in our ELISA. Moreover, our ELISA showed 100% specificity in 342 challenging dengue-negative samples. The large and diverse mAb repertoire generated against DENV NS1 and the appropriate selection of mAbs allowed us to establish an ELISA that can efficiently detect NS1 Ag even in secondary dengue and without serotype level bias.
Mesothelium-Derived Factors Shape GATA6-Positive Large Cavity Macrophages
Authors: Lai Chin-Wen , Bagadia Prachi , Barisas Derek A G , Jarjour Nicholas N , Wong Rachel , Ohara Takahiro , Muegge Brian D , Lu Qiuhe , Xiong Shanshan , Edelson Brian T , Murphy Kenneth M , Stappenbeck Thaddeus S
Published: January 2023

The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln−/− and Muc16−/− mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell–produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.
Androgens Alleviate Allergic Airway Inflammation by Suppressing Cytokine Production in Th2 Cells
Authors: Ejima Aki , Abe Shinya , Shimba Akihiro , Sato Susumu , Uehata Takuya , Tani-ichi Shizue , Munakata Satoru , Cui Guangwei , Takeuchi Osamu , Hirai Toyohiro , Kato Shigeaki , Ikuta Koichi
Published: January 2023

Asthma is more common in females than males after adolescence. However, the mechanism of the sex bias in the prevalence of asthma remains unknown. To test whether sex steroid hormones have some roles in T cells during development of asthma, we analyzed airway inflammation in T cell–specific androgen receptor (AR)– and estrogen receptor (ER)–deficient mice. T cell–specific AR-deficient male mice developed severer house dust mite–induced allergic airway inflammation than did control male mice, whereas T cell–specific ERα- and ERβ-deficient female mice exhibited a similar degree of inflammation as for control female mice. Furthermore, administration of dihydrotestosterone reduced cytokine production of Th2 cells from control, but not AR-deficient, naive T cells. Transfer of OT-II transgenic AR-deficient Th2 cells into wild-type mice induced severer allergic airway inflammation by OVA than transfer of control Th2 cells. Gene expression profiling suggested that the expression of genes related with cell cycle and Th2 differentiation was elevated in AR-deficient Th2 cells, whereas expression of dual specificity phosphatase (DUSP)-2, a negative regulator of p38, was downregulated. In addition, a chromatin immunoprecipitation assay suggested that AR bound to an AR motif in the 5′ untranslated region of the Dusp2 gene in Th2 cells. Furthermore, the Dusp2 promoter with a wild-type AR motif, but not a mutated motif, was transactivated by dihydrotestosterone in a reporter assay. Finally, forced expression of DUSP-2 by retrovirus vector reduced IL-4 expression in Th2 cells. Thus, these results suggest that androgen signaling suppresses cytokine production of Th2 cells by inducing DUSP-2, explaining, in part, the sex bias of asthma after adolescence.
Longitudinal Immune Profiling Highlights CD4+ T Cell Exhaustion Correlated with Liver Fibrosis in Schistosoma japonicum Infection
Authors: Ren Jiling , Zhuo Yue , He Furong , Lv Lihui , Xing Man , Guo Yingying , Zhang Yuchao , Liu Jiaojiao , Li Ying , Bai Tinghui , Chen Yanan , Li Guangru , Qin Zhiqiang , Zhou Dongming
Published: January 2023

Schistosomiasis remains an important public health concern. The eggs deposited in livers invoke a Th2-dominant response, which mediates the fibrotic granulomatous response. However, the mechanisms involved in this immunopathological process are still not perfectly clear. Here, we report a single-cell transcriptional landscape of longitudinally collected BALB/c mouse splenocytes at different time points after Schistosoma japonicum infection. We found that exhausted CD4+ T cells were enriched after infection, changing from coproducing multiple cytokines to predominantly producing the Th2 cytokine IL-4. Regulatory B cells had high expression of Fcrl5, Ptpn22, and Lgals1, potentially regulating exhausted CD4+ T cells via direct PD-1–PD-L2 and PD-1–PD-L1 interactions. Within the myeloid compartment, the number of precursor and immature neutrophils sharply increased after infection. Moreover, dendritic cells, macrophages, and basophils showed inhibitory interactions with exhausted CD4+ T cells. Besides, in mouse livers, we found that exhausted CD4+ T cells were distributed around egg granuloma, promoting collagen expression in primary mouse hepatic stellate cells via IL-4 secretion, resulting in liver fibrosis. Our study provides comprehensive characterization of the composition and cellular states of immune cells with disease progression, which will facilitate better understanding of the mechanism underlying liver fibrotic granulomatous response in schistosomiasis.
TAK1 Limits Death Receptor Fas-Induced Proinflammatory Cell Death in Macrophages
Authors: Maeda Kengo , Nakayama Jun , Taki Shinsuke , Sanjo Hideki
Published: January 2023

Fas, a member of the death receptor family, plays a central role in initiating cell death, a biological process crucial for immune homeostasis. However, the immunological and pathophysiological impacts to which enhanced Fas signaling gives rise remain to be fully understood. Here we demonstrate that TGF-β–activated kinase 1 (TAK1) works as a negative regulator of Fas signaling in macrophages. Upon Fas engagement with high concentrations of FasL, mouse primary macrophages underwent cell death, and, surprisingly, Fas stimulation led to proteolytic cleavage of gasdermin (GSDM) family members GSDMD and GSDME, a hallmark of pyroptosis, in a manner dependent on caspase enzymatic activity. Remarkably, TAK1-deficient macrophages were highly sensitive to even low concentrations of FasL. Mechanistically, TAK1 negatively modulated RIPK1 kinase activity to protect macrophages from excessive cell death. Intriguingly, mice deficient for TAK1 in macrophages (TAK1mKO mice) spontaneously developed tissue inflammation, and, more important, the emergence of inflammatory disease symptoms was markedly diminished in TAK1mKO mice harboring a catalytically inactive RIPK1. Taken together, these findings not only revealed an unappreciated role of TAK1 in Fas-induced macrophage death but provided insight into the possibility of perturbation of immune homeostasis driven by aberrant cell death.
Reduced T Cell Priming in Microbially Experienced “Dirty” Mice Results from Limited IL-27 Production by XCR1+ Dendritic Cells
Authors: Sjaastad Frances V , Huggins Matthew A , Lucas Erin D , Skon-Hegg Cara , Swanson Whitney , Martin Matthew D , Salgado Oscar C , Xu Julie , Pierson Mark , Dileepan Thamotharampillai , Kucaba Tamara A , Hamilton Sara E , Griffith Thomas S
Published: January 2023

Successful vaccination strategies offer the potential for lifelong immunity against infectious diseases and cancer. There has been increased attention regarding the limited translation of some preclinical findings generated using specific pathogen-free (SPF) laboratory mice to humans. One potential reason for the difference between preclinical and clinical findings lies in maturation status of the immune system at the time of challenge. In this study, we used a “dirty” mouse model, where SPF laboratory mice were cohoused (CoH) with pet store mice to permit microbe transfer and immune system maturation, to investigate the priming of a naive T cell response after vaccination with a peptide subunit mixed with polyinosinic-polycytidylic acid and agonistic anti-CD40 mAb. Although this vaccination platform induced robust antitumor immunity in SPF mice, it failed to do so in microbially experienced CoH mice. Subsequent investigation revealed that despite similar numbers of Ag-specific naive CD4 and CD8 T cell precursors, the expansion, differentiation, and recall responses of these CD4 and CD8 T cell populations in CoH mice were significantly reduced compared with SPF mice after vaccination. Evaluation of the dendritic cell compartment revealed reduced IL-27p28 expression by XCR1+ dendritic cells from CoH mice after vaccination, correlating with reduced T cell expansion. Importantly, administration of recombinant IL-27:EBI3 complex to CoH mice shortly after vaccination significantly boosted Ag-specific CD8 and CD4 T cell expansion, further implicating the defect to be T cell extrinsic. Collectively, our data show the potential limitation of exclusive use of SPF mice when testing vaccine efficacy.
The Human Dendritic Cell Atlas: An Integrated Transcriptional Tool to Study Human Dendritic Cell Biology
Authors: Elahi Zahra , Angel Paul W , Butcher Suzanne K , Rajab Nadia , Choi Jarny , Deng Yidi , Mintern Justine D , Radford Kristen , Wells Christine A
Published: January 2023

Dendritic cells (DCs) are functionally diverse and are present in most adult tissues, but deep understanding of human DC biology is hampered by relatively small numbers of these in circulation and their short lifespan in human tissues. We built a transcriptional atlas of human DCs by combining samples from 14 expression profiling studies derived from 10 laboratories. We identified significant gene expression variation of DC subset–defining markers across tissue type and upon viral or bacterial stimulation. We further highlight critical gaps between in vitro–derived DC subsets and their in vivo counterparts and provide evidence that monocytes or cord blood progenitor in vitro–differentiated DCs fail to capture the repertoire of primary DC subsets or behaviors. In constructing a reference DC atlas, we provide an important resource for the community wishing to identify and annotate tissue-specific DC subsets from single-cell datasets, or benchmark new in vitro models of DC biology.
Lipopolysaccharide Primes Human Macrophages for Noncanonical Inflammasome-Induced Extracellular Vesicle Secretion
Authors: Cypryk Wojciech , Czernek Liliana , Horodecka Katarzyna , Chrzanowski Jędrzej , Stańczak Marcin , Nurmi Katariina , Bilicka Marcelina , Gadzinowski Mariusz , Walczak-Drzewiecka Aurelia , Stensland Maria , Eklund Kari , Fendler Wojciech , Nyman Tuula A , Matikainen Sampsa
Published: January 2023

Human macrophages secrete extracellular vesicles (EVs) loaded with numerous immunoregulatory proteins. Vesicle-mediated protein secretion in macrophages is regulated by poorly characterized mechanisms; however, it is now known that inflammatory conditions significantly alter both the quantities and protein composition of secreted vesicles. In this study, we employed high-throughput quantitative proteomics to characterize the modulation of EV-mediated protein secretion during noncanonical caspase-4/5 inflammasome activation via LPS transfection. We show that human macrophages activate robust caspase-4–dependent EV secretion upon transfection of LPS, and this process is also partially dependent on NLRP3 and caspase-5. A similar effect occurs with delivery of the LPS with Escherichia coli–derived outer membrane vesicles. Moreover, sensitization of the macrophages through TLR4 by LPS priming prior to LPS transfection dramatically augments the EV-mediated protein secretion. Our data demonstrate that this process differs significantly from canonical inflammasome activator ATP-induced vesiculation, and it is dependent on the autocrine IFN signal associated with TLR4 activation. LPS priming preceding the noncanonical inflammasome activation significantly enhances vesicle-mediated secretion of inflammasome components caspase-1, ASC, and lytic cell death effectors GSDMD, MLKL, and NINJ1, suggesting that inflammatory EV transfer may exert paracrine effects in recipient cells. Moreover, using bioinformatics methods, we identify 15-deoxy-Δ12,14-PGJ2 and parthenolide as inhibitors of caspase-4–mediated inflammation and vesicle secretion, indicating new therapeutic potential of these anti-inflammatory drugs.
B Cells Drive MHC Class I–Restricted CD4 T Cells to Induce Spontaneous Central Nervous System Autoimmunity
Authors: Matter Aubry L , Liggitt Denny , Goverman Joan M
Published: January 2023

Multiple sclerosis (MS) is an inflammatory, demyelinating CNS disease believed to be mediated by CD4 T cells specific for CNS self-antigens. CD8 T cells are also implicated in MS but their function is not well understood. MS lesions are heterogeneous and may reflect variation in the contribution of different types of lymphocytes. Understanding how lymphocytes with different effector functions contribute to MS is essential to develop effective therapies. We investigated how T cells expressing an MHC class I–restricted transgenic TCR specific for myelin basic protein (MBP) contribute to CNS autoimmunity using the mouse model of MS, experimental autoimmune encephalomyelitis. Virus infection triggered cytotoxic TCR-transgenic CD8 T cells to initiate acute experimental autoimmune encephalomyelitis in an IFN-γ– and perforin-dependent manner. Unexpectedly, spontaneous CNS autoimmunity developed in the TCR-transgenic mice that was accelerated by IFN-γ-deficiency. Spontaneous disease was associated with CD4 T cells that develop via endogenous TCR rearrangements but retain specificity for the MHC class I–restricted MBP epitope. The CD4 T cells produced TNF-α without other inflammatory cytokines and caused lesions with striking similarity to active MS lesions. Surprisingly, B cells were the predominant cell type that cross-presented MBP, and their depletion halted disease progression. This work provides a new model of spontaneous CNS autoimmunity with unique similarities to MS that is mediated by T cells with a distinct effector phenotype.
E6020, a TLR4 Agonist Adjuvant, Enhances Both Antibody Titers and Isotype Switching in Response to Immunization with Hapten-Protein Antigens and Is Diminished in Mice with TLR4 Signaling Insufficiency
Authors: Gopalakrishnan Archana , Richard Katharina , Wahid Rezwanul , Harley Regina , Sztein Marcelo B , Hawkins Lynn D , Vogel Stefanie N
Published: January 2023

The mechanisms by which TLR4-based adjuvants enhance immunogenicity are not fully understood. We have taken advantage of a novel knock-in mouse strain that homozygously expresses two single-nucleotide polymorphisms (SNPs) that are homologous to human TLR4 (rs4986790 and rs4986791) and have been associated with LPS hyporesponsiveness in vivo and in vitro. TLR4-SNP (coexpressing mutations D298G/N397I in TLR4) mice that recapitulate the human phenotype were compared with wild-type (WT) mice for their hapten-specific Ab responses after immunization with hapten 4-hydroxy-3-nitrophenyl acetyl (NP) NP-Ficoll or NP-OVA in the absence or presence of a water-soluble TLR4 analog adjuvant, E6020. IgM and IgG anti-NP responses were comparable in WT and TLR4-SNP mice after immunization with either NP-Ficoll or NP-OVA only. E6020 significantly yet transiently improved the IgM and IgG anti-NP responses of both WT and TLR4-SNP mice to NP-Ficoll (T-independent), with modestly enhanced Ab production in WT mice. In contrast, T-dependent (NP-OVA), adjuvant-enhanced responses showed sustained elevation of NP-specific Ab titers in WT mice, intermediate responses in TLR4-SNP mice, and negligible enhancement in TLR4−/− mice. E6020-enhanced early humoral responses in WT and TLR4-SNP mice to NP-OVA favored an IgG1 response. After a second immunization, however, the immune responses of TLR4-SNP mice remained IgG1 dominant, whereas WT mice reimmunized with NP-OVA and E6020 exhibited increased anti-NP IgG2c titers and a sustained increase in the IgG1 and IgG2c production by splenocytes. These findings indicate that E6020 increases and sustains Ab titers and promotes isotype class switching, as evidenced by reduced titers and IgG1-dominant immune responses in mice with TLR4 insufficiency.
The Impact of Helminth Coinfection on Innate and Adaptive Immune Resistance and Disease Tolerance during Toxoplasmosis
Authors: Rovira-Diaz Eliezer , El-Naccache Darine W , Reyes Jojo , Zhao Yanlin , Nasuhidehnavi Azadeh , Chen Fei , Gause William C , Yap George S
Published: January 2023

More than 2 billion people worldwide are infected with helminths. Thus, it is possible for individuals to experience concomitant infection with helminth and intracellular microbes. Although the helminth-induced type 2 response can suppress type 1 proinflammatory responses required for the immunity against intracellular pathogens in the context of a coinfection, conflicting evidence suggest that helminth infection can enhance antimicrobial immunity. Using a coinfection model with the intestinal helminth Heligmosomoides polygyrus followed by infection with Toxoplasma gondii in Mus Musculus, we showed that the complex and dynamic effect of helminth infection is highly suppressive during the innate phase (days 0–3) of T. gondii infection and less stringent during the acute phase (d10). Helminth coinfection had a strong suppressive effect on the neutrophil, monocytic, and early IFN-γ/IL-12 responses. The IFN-γ response was later restored by compensatory production from T cells despite decreased effector differentiation of T. gondii–specific CD8 T cells. In accordance with the attenuated IFN-γ response, parasite loads were elevated during the acute phase (d10) of T. gondii infection but were transiently controlled by the compensatory T cell response. Unexpectedly, 40% of helminth-coinfected mice exhibited a sustained weight loss phenotype during the postacute phase (d14–18) that was not associated with T. gondii outgrowth, indicating that coinfection led to decreased disease tolerance during T. gondii infection. Our work uncovers the dynamic nature of the helminth immunomodulatory effects on concomitant infections or immune responses and unveils a loss of disease tolerance phenotype triggered by coinfection with intestinal helminth.
Cutting Edge: CCR9 Promotes CD8+ T Cell Recruitment to the Brain during Congenital Cytomegalovirus Infection
Authors: Hilt Zachary T , Charles Wisler , Cheng Katarina E , Tabilas Cybelle , Steinhilber Megan , Wesnak Samantha P , Smith Norah L , Schaffer Chris B , Rudd Brian D
Published: January 2023

CD8+ T lymphocytes infiltrate the brain during congenital CMV infection and promote viral clearance. However, the mechanisms by which CD8+ T cells are recruited to the brain remain unclear. Using a mouse model of congenital CMV, we found a gut-homing chemokine receptor (CCR9) was preferentially expressed in CD8+ T cells localized in the brain postinfection. In the absence of CCR9 or CCL25 (CCR9’s ligand) expression, CD8+ T cells failed to migrate to key sites of infection in the brain and protect the host from severe forms of disease. Interestingly, we found that expression of CCR9 on CD8+ T cells was also responsible for spatial temporal positioning of T cells in the brain. Collectively, our data demonstrate that the CMV-infected brain uses a similar mechanism for CD8+ T cell homing as the small intestine.
G307S DNAM-1 Mutation Exacerbates Autoimmune Encephalomyelitis via Enhancing CD4+ T Cell Activation
Authors: Murata Rikito , Kinoshita Shota , Matsuda Kenshiro , Kawaguchi Atsushi , Shibuya Akira , Shibuya Kazuko
Published: January 2023

Although rs763361, which causes a nonsynonymous glycine-to-serine mutation at residue 307 (G307S mutation) of the DNAX accessory molecule-1 (DNAM-1) immunoreceptor, is a single-nucleotide polymorphism associated with autoimmune disease susceptibility, little is known about how the single-nucleotide polymorphism is involved in pathogenesis. In this study, we established human CD4+ T cell transfectants stably expressing wild-type (WT) or G307S DNAM-1 and showed that the costimulatory signal from G307S DNAM-1 induced greater proinflammatory cytokine production and cell proliferation than that from wild-type DNAM-1. The G307S mutation also enhanced the recruitment of the tyrosine kinase Lck and augmented p-Tyr322 of DNAM-1. We also established a mouse myelin Ag–specific CD4+ T cell transfectant stably expressing the chimeric DNAM-1 (chDNAM-1) consisting of the extracellular, transmembrane, and a part of intracellular regions of mouse DNAM-1 (residues 1–285) fused with the part of the intracellular region (residues 286–336) of human WT or G307S chDNAM-1. Adoptive transfer of the mouse T cell transfectant expressing the G307S chDNAM-1 into mice exacerbated experimental autoimmune encephalomyelitis compared with the transfer of cells expressing the WT chDNAM-1. These findings suggest that rs763361 is a gain-of-function mutation that enhances DNAM-1–mediated costimulatory signaling for proinflammatory responses.
Diversity in Cortical Thymic Epithelial Cells Occurs through Loss of a Foxn1-Dependent Gene Signature Driven by Stage-Specific Thymocyte Cross-Talk
Authors: White Andrea J , Parnell Sonia M , Handel Adam , Maio Stefano , Bacon Andrea , Cosway Emilie J , Lucas Beth , James Kieran D , Cowan Jennifer E , Jenkinson William E , Hollander Georg A , Anderson Graham
Published: January 2023

In the thymus, cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells support αβT cell development from lymphoid progenitors. For cTECs, expression of a specialized gene signature that includes Cxcl12, Dll4, and Psmb11 enables the cortex to support T lineage commitment and the generation and selection of CD4+CD8+ thymocytes. Although the importance of cTECs in T cell development is well defined, mechanisms that shape the cTEC compartment and regulate its functional specialization are unclear. Using a Cxcl12DsRed reporter mouse model, we show that changes in Cxcl12 expression reveal a developmentally regulated program of cTEC heterogeneity. Although cTECs are uniformly Cxcl12DsRed+ during neonatal stages, progression through postnatal life triggers the appearance of Cxcl12DsRed− cTECs that continue to reside in the cortex alongside their Cxcl12DsRed+ counterparts. This appearance of Cxcl12DsRed− cTECs is controlled by maturation of CD4−CD8−, but not CD4+CD8+, thymocytes, demonstrating that stage-specific thymocyte cross-talk controls cTEC heterogeneity. Importantly, although fate-mapping experiments show both Cxcl12DsRed+ and Cxcl12DsRed− cTECs share a common Foxn1+ cell origin, RNA sequencing analysis shows Cxcl12DsRed− cTECs no longer express Foxn1, which results in loss of the FOXN1-dependent cTEC gene signature and may explain the reduced capacity of Cxcl12DsRed− cTECs for thymocyte interactions. In summary, our study shows that shaping of the cTEC compartment during the life course occurs via stage-specific thymocyte cross-talk, which drives loss of Foxn1 expression and its key target genes, which may then determine the functional competence of the thymic cortex.
HLA Class I Supertype Classification Based on Structural Similarity
Authors: Shen Yue , Parks Jerry M , Smith Jeremy C
Published: January 2023

HLA class I proteins, a critical component in adaptive immunity, bind and present intracellular Ags to CD8+ T cells. The extreme polymorphism of HLA genes and associated peptide binding specificities leads to challenges in various endeavors, including neoantigen vaccine development, disease association studies, and HLA typing. Supertype classification, defined by clustering functionally similar HLA alleles, has proven helpful in reducing the complexity of distinguishing alleles. However, determining supertypes via experiments is impractical, and current in silico classification methods exhibit limitations in stability and functional relevance. In this study, by incorporating three-dimensional structures we present a method for classifying HLA class I molecules with improved breadth, accuracy, stability, and flexibility. Critical for these advances is our finding that structural similarity highly correlates with peptide binding specificity. The new classification should be broadly useful in peptide-based vaccine development and HLA–disease association studies.
Increased levels of circulating platelet microparticles as a risk of hypercoagulable state in β-thalassemia intermedia patients
Authors: Abdel Aziz Hanan M. , El-Beih Esam A.S. , Sayed Douaa M. , Afifi Ola A. , Thabet Ahmad F. , Elgammal Sahar , Mansor Shima G. , Moeen Sawsan M.
Published: January 2023

Introduction

Thromboembolism is a frequent complication in thalassemia. Platelet microparticles (PMPs) may have a role in the hypercoagulability in thalassemia.

Objective

To determine the levels of PMPs in β-thalassemia intermedia (β-TI) patients and whether increased levels of PMPs in these patients are correlated with coagulation parameters or not.

Patients and methods

Sixty-three β-TI patients, classified into 46 nonsplenectomized (NS) patients, 17 splenectomized (S) patients, and 20 age-matched and sex-matched volunteers as controls. For all, full medical history, through clinical examination, and laboratory investigations: complete blood count, prothrombin time, prothrombin concentration, activated partial thromboplastin time, FVIII, FXI, fibrinogen, D-dimer, and PMPs were detected by using flow-cytometry approach.

Results

PMPs were significantly higher in S and NS β-TI patients than controls (P<0.001, P=0.002), respectively. FVIII and D-dimer were significantly higher in S patients than controls (P=0.004, 0.048), respectively. Fibrinogen level was significantly lower in both NS and S β-TI patients than in controls (P<0.001). A significant positive correlation between PMPs and platelet count in S patients (r=0.549, P=0.023).

Conclusion

Thrombotic risk in β-TI patients is related to increased circulating PMPs and platelet count. Splenectomy was considered a risk factor of thrombosis in our study.
A rare case report of Intravascular Diffuse Large B cell Lymphoma presenting as subcutaneous nodules
Authors: N P Prakash , Gayatri Gopan , Vishnu Hari , A V Jayasudha
Published: January 2023

Intravascular diffuse large B-cell lymphoma is a rare entity where the large lymphoma cells are seen within the vessels. The difficulty is in its diagnosis, as it can have varied presentations affecting multiple systems. Here, we present the case report of a woman with intravascular diffuse large B-cell lymphoma who presented with subcutaneous nodules.