bluuebunny/crossref_metadata_2025_split huggingface dataset:
cIAP1/2-TRAF2- SHP1-Src-MyD88 complex regulates LPS-induced IL-27 production through NFkB activation in human macrophages
Authors: Kumar Ashok , Busca Aurelia , Gajanayaka Niranjala , Angel Jonathan 
Published: January 2023

Abstract
The inhibitors of apoptosis (IAP) proteins, initially described in the context of apoptosis regulation as promoting cell survival, have recently emerged as key regulators of innate immune signaling. As a result, downregulation of IAP via Smac mimetics (SMM) has both survival and immunoregulatory effects. IAPs modulate cytokine production in murine models either as a single agent or in response to LPS. However, the role of SMM and the involvement of IAPs in primary human cells and in particular macrophages with respect to cytokine production and innate immune responses remain largely unknown. IL-27, a member of the IL-12 cytokine family produced by antigen presenting cells such as macrophages, has broad immunoregulatory properties in both innate and adaptive immune responses. Herein, we show that cIAPs positively regulate LPS-induced IL-27 production in both primary human monocytes and macrophages. Investigations for the signaling mechanism of cIAPs involvement in IL-27 production in human macrophages revealed that LPS-induced IL-27 production is regulated by a novel signaling complex comprising of cIAP1/2, TNF receptor associated factor-2 (TRAF2), SHP-1, Src, and MyD88 leading to p38, C-Jun N-terminal kinases (JNK) and Akt activation and NFκB signaling. In cancer cells, SMM induce the production of cytokines by activating the non-canonical alternate NFkB pathway. However, in human macrophages, SMM do not induce the production of TNF-a and other cytokines while inhibiting LPS-induced IL-27 production by inhibiting the classical NFkB pathway. These signaling pathways may constitute novel therapeutic avenues for immune-modulation of IL-27 and provide insight into the modulatory immune effects of SMM.
Inhibition of mTORC1 activity is required for the IL-12p40 response of classical CD16neg CD14+ primary human monocytes to Toxoplasma gondii
Authors: Amancio Alice Muglia T. S. , Mittereder Lara , Carletti Alexie , Sher Alan , Jankovic Dragana 
Published: January 2023

Abstract
Primary human monocytes produce IL-12 and TNF in response to live Toxoplasma gondii tachyzoytes by a mechanism requiring parasite phagocytosis. Interestingly, in contrast to the patrolling CD16+ CD14+ subset, monocytes belonging to the major CD16neg CD14+ subset fail to secrete IL-12 and TNF following T. gondii exposure. Here we show that the CD16neg CD14+ subset, nevertheless, upregulates Il12b mRNA and thus is able to sense the parasite. In addition, we demonstrate that priming with IFNg, but not IFNa, enables CD16negCD14+ monocytes to produce IL-12 protein in response to T. gondii. This effect of IFNg priming was not due to augmented phagocytosis and was not associated with altered rates of glycolysis, oxygen consumption, or increased Il12b mRNA expression. To test the possible role of IFNγ on cytokine translation, we evaluated the requirement for mTOR (mTORC1/2) pathway, a key regulator of protein synthesis. The T. gondii-induced IL-12 response of IFNγ primed CD16neg monocytes was inhibited by Torin, an inhibitor of mTORC2, but surprisingly not by the classical mTORC1 inhibitor Rapamycin. Because mTORC2 has been shown to downregulate mTORC1 activity, we hypothesized that the priming effect of IFNg might result from the upregulation of mTORC2 resulting in suppressed mTORC1. Indeed, in the absence of IFNγ, suppression of mTORC1 in CD16neg monocytes with Rapamycin enhanced IL-12 secretion. Taken together, our results suggest that classical CD16neg CD14+ monocytes fail to secrete IL-12 in response to T. gondii due to increased mTORC1 activity, which can be reversed directly by Rapamycin or indirectly through stimulation of mTORC2 by IFNγ priming.
Exploring a role for Human Herpesvirus 6B-mediated mitochondrial dysfunction in dysregulating antiviral innate immunity
Authors: Birdwell Christine E. , West Phillip 
Published: January 2023

Abstract
Human herpesviruses are ubiquitous in the world population, in part due to the ability of this family of viruses to establish life-long, persistent infections. Human herpesvirus 6B (HHV-6B) is generally acquired early in life, and is the causative agent of the benign childhood febrile illness, Roseola Infantum, and severe encephalitis in rare instances. Mitochondria play diverse roles in cell homeostasis, including metabolism, energy production, and regulation of antiviral innate immunity. As a family, herpesviruses are known modulators of mitochondria and we have observed that HHV-6B significantly alters mitochondrial function of infected T-cells. Specifically, we have discovered that HHV-6B alters mitochondrial DNA replication and transcription, while also dramatically decreasing mitochondrial membrane potential during infection. We hypothesize that HHV-6 disrupts mitochondrial function by altering mitochondrial gene expression and oxidative phosphorylation, leading to metabolic and signaling imbalances that influence cellular homeostasis and anti-HHV-6 immunity.
Trajectory of neuro-inflammation and microglial activation assessed using Translocator protein (18kDa TSPO) and positron emission tomography (PET) imaging in bacterial meningitis
Authors: Barichello Tatiana , Giridharan Vijayasree V. , Scaini Giselli , Generoso Jaqueline S. , Simões Lutiana Roque , Dominguini Diogo , Hasbun Rodrigo , Selvaraj Sudhakar , Dal-Pizzol Felipe 
Published: January 2023

Abstract
Here we present novel data from acute (24 hours) and chronic (10 days) pneumococcal meningitis rat survivors evaluating microglia activation through [11C] PBR28, a tracer targeting the TSPO using PET-imaging. Wistar rats received an injection of Streptococcus pneumoniae or artificial-CSF through the cisterna magna following by ceftriaxone/100 mg/kg/7days. At 24 hours and 10 days the animals were subjected to TSPO-PET-imaging. Following the imaging IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, IL-13, IL-17, IL-18, IFN-γ, TNF-α, and microglial marker Iba-1 and astrocyte marker GFAP were evaluated in prefrontal cortex and hippocampus (n = 7). In chronic phase, the animals were subjected to open field, step-down inhibitory avoidance and in novel object recognition task, n = 10. In acute phase, the imaging results revealed that in amygdala, cortex, hippocampus, hypothalamus, midbrain, and thalamus (p &lt; 0.05) uptake of [11C] PBR28 was greater in the meningitis group as compared to the control group. We observed increased expression of pro-inflammatory markers such as IL-1α, IL-1β, IL-6, IL-18, IFN-γ, TNF-α, Iba-1, and GFAP expression at 24 h (p &lt; 0.05). In the chronic phase, in amygdala, hippocampus, and thalamus (p &lt; 0.05) uptake of [11C] PBR28 was greater in the meningitis group. The control group presented retention of habituation memory, aversive memory and long-term recognition memory. However, animals in the meningitis group demonstrated memory impairment in all behavioral tasks. TNF-α, Iba-1, and GFAP expression increased in chronic phase survivors (p &lt; 0.05). The above results support our hypothesis that increased activation of brain microglia is associated with behavioral changes in experimental model of meningitis.
AAK1 and GAK inhibitors demonstrate activity against Filoviruses
Authors: Dorosky Danielle , Prugar Laura I. , Pu Szuyan , O’Brien Cecilia , Bakken Russell , De Jonghe Steven , Herdewijn Piet , Brannan Jennifer , Dye John M. , Einav Shirit 
Published: January 2023

Abstract
Ebola virus (EBOV) and Marburg virus (MARV) are highly pathogenic members of the family filoviridae. The recent West Africa epidemic of Ebola virus disease was a grave reminder of the unmet need for post exposure therapeutics to combat filovirus infection. Our group has reported that multiple unrelated viruses, including EBOV, commandeer host kinases AP2-associated protein kinase-1 (AAK1) and cyclin G-associated kinase (GAK) during viral entry, assembly, and/or egress. This shared attribute makes AAK1 and GAK desirable broad-spectrum targets for the treatment of multiple viral infections without necessitating species identification. As the targets of these inhibitors are host cell factors, this may allow for the reduction in the likelihood that the virus will develop drug resistance. We have demonstrated that treatment with sunitinib and erlotinib, approved anticancer drugs with anti-AAK1 or GAK activity, is effective in inhibiting replication of Ebola, Hepatitis C and Dengue (DENV) viruses in vitro. Additionally, the combination of sunitinib and erlotinib has demonstrated efficacy in reducing morbidity and mortality following challenge with EBOV and DENV in the relevant mouse models. In an effort to improve toxicity and survival, we are developing novel, chemically distinct, more selective inhibitors of AAK1 and GAK. Here we describe the capability of these next generation AAK1 and GAK inhibitors to reduce in vitro infection of Ebola virus and Marburg virus.
Unique phenotypes and clonal expansions of human CD4 effector memory T cells re-expressing CD45RA
Authors: Tian Yuan , Babor Mariana , Lane Jerome , Schulten Véronique MJ. , Patil Veena , Seumois Grégory , Rosales Sandy , Fu Zheng , Picarda Gaelle Genevieve Alice , Burel Julie , Zapardiel-Gonzalo Jose , Tennekoon Rashika , De Silva Aruna , Premawansa Sunil , Premawansa Gayani , Wijewickrama Ananda , Greenbaum Jason , Vijayanand Pandurangan , Weiskopf Daniela , Sette Alessandro , Peters Bjorn 
Published: January 2023

Abstract
The expression of CD45RA is generally associated with naive T cells. However, a subset of effector memory T cells re-expresses CD45RA (termed TEMRA) after antigenic stimulation with unknown molecular characteristics and functions. CD4 TEMRA cells have been implicated in protective immunity against pathogens such as dengue virus (DENV). Here we show that not only the frequency but also the phenotype of CD4 TEMRA cells are heterogeneous between individuals. These cells can be subdivided into two major subsets based on the expression of the adhesion G protein-coupled receptor GPR56, and GPR56+ TEMRA cells display a transcriptional and proteomic program with cytotoxic features that is distinct from effector memory T cells. Moreover, GPR56+ TEMRA cells have higher levels of clonal expansion and contain the majority of virus-specific TEMRA cells. Overall, this study reveals the heterogeneity of CD4 TEMRA cells and provides insights into T-cell responses against DENV and other viral pathogens.
CD28 Induces Mitochondrial Respiration Dependent Reactive Oxygen Species (ROS) Signaling for Metabolic Fitness and Survival in Long-Lived Plasma Cells
Authors: Utley Adam , Cooper James J. M. , Chavel Colin A. , Peng Peng , Carlson Louise M. , Lightman Shivana M. , Kambayashi Taku , Green Jonathan , Lee Kelvin P. 
Published: January 2023

Abstract
Durable humoral immunity depends upon bone marrow resident long-lived plasma cell (LLPC) survival. We have shown that CD28, the canonical T-cell costimulatory molecule, is required for LLPC survival; however, the mechanistic basis for this is unclear. We have published that of two binding motifs in the CD28 cytoplasmic tail, only the Grb2/Vav moiety, and not the direct PI3k binding motif, supports CD28-mediated survival. CD28 is known to induce glycolysis in T-cells. In contrast, CD28 activation in both LLPCs and human PCs induces glucose metabolism through mitochondrial respiration. A major byproduct of mitochondrial respiration is the production of reactive oxygen species (ROS). Interestingly, the mitochondrial respiration-dependent production of ROS is required for CD28-mediated survival. Previously published data demonstrate the ability of ROS to signal through both NFkB and PI3k. CD28-induced ROS signal through PI3k in LLPCs for increased glucose uptake and the inhibition of PI3k prevents CD28-mediated survival. The ROS-PI3k signal drives the phosphorylation of both S6k and rpS6, downstream targets of mTORC1, and this regulation is independent of Blimp1 expression. Irf4, a critical PC survival factor, is upregulated by CD28-dependent NFkB activation. To our great surprise, ROS inhibition prevented the induction of mitochondrial respiration itself, demonstrating that signals emanating downstream of ROS govern the metabolic program for survival in LLPCs. Taken together, these data suggest a model wherein CD28 signals directly through Grb2/Vav to induce mitochondrial respiration and ROS production. ROS then reinforce signaling through PI3k and NFkB to increase Irf4 expression and metabolic fitness for LLPC survival.
The long chain fatty acid transporter, MFSD2A, is essential for memory CD8+ T cell formation and maintenance
Authors: Piccirillo Ann R. , Hawse William F. , Buechel Heather M. , Silver David L. , D’Cruz Louise M. 
Published: January 2023

Abstract
Access to nutrients is critical for an effective T cell immune response to infection. Although transporters for sugars and amino acids have previously been described in the context of the CD8+ T cell immune response, the active transport of exogenous esterified fatty acids has remained enigmatic. Here we discovered the long chain fatty acid transporter, Major Facilitator Super Family Domain Containing 2a (MFSD2A), is upregulated on activated CD8+ T cells and is essential for their memory cell formation. MFSD2A deficiency resulted in decreased import of long chain fatty acids (LCFAs) esterified to lysophosphatidylcholine (LPC) into activated CD8+ T cells but overall resulted in a normal primary effector T cell response. However, loss of MFSD2A led to reduced memory T cell formation and maintenance. MFSD2A deficient memory CD8+ T cells showed reduced CD127 and CD62L expression and their cell turnover was significantly impaired in contrast to their wildtype counterparts. Moreover, the secondary response to infection was severely diminished in MFSD2A deficient T cells. Mechanistically, import of LCFAs was required to maintain cell energy requirements and ‘fitness’, that when lost resulted in a decreased memory T cell pool and inability to proliferate upon secondary stimulation. Our results show that MFSD2A and LPC may be useful for future small molecule therapy design to generate a more robust T cell response for new vaccines or cancer treatments.
CD45RB Status Defines TCR Priming Affinity and CD8+ T Cell Memory Persistence
Authors: Krummey Scott , Jacobs Jesica R. , Kissick Haydn , Evavold Brian D. , Ford Mandy L. 
Published: January 2023

Abstract
T cell receptor (TCR) affinity plays a critical role in shaping T cell differentiation, but few studies have investigated the role of TCR affinity in the context of the endogenous CD8+ T cell memory pool. While naïve CD8+ T cells express primarily large CD45 isoforms (denoted as CD45RBhi), CD8+ T cell memory cells are traditionally described as expressing small isoforms (CD45RBlo). Interestingly, although CD8+ T cell memory to acute infection with LCMV included CD45RBlo cells, we found that over half of the CD8+ T cell memory pool remained CD45RBhi. The 2D micropipette affinity assay revealed that CD45RBhi memory cells had a 29-fold lower affinity for antigen relative to CD45RBlo cells. CD45RBloand CD45RBhi memory cells expressed similar levels of granzyme B and IFN-γ, but RNASeq analysis revealed that these populations differentially expressed over 150 genes. Phenotypically, the CD45RBhi population contained a higher frequency of the CD62LhiCD27hiCD127hiKLRG1lo persistent memory phenotype compared to CD45RBlo cells. We found that from early to late memory time-points, portions of each of the CD45RBhi and CD45RBlo populations underwent conversion to CD62Lhi, demonstrating that CD45RB status is distinct from the TCM phenotype. Adoptive transfer of purified CD45RBhi and CD45RBlo populations into naïve mice revealed that CD45RBlo memory cells underwent significant cell loss relative to CD45RBhi memory cells. Over time, the majority of CD45RBlo cells homeostatically converted to the CD45RBhipersistent memory phenotype. Together, these data demonstrate a novel role for CD45RB expression as a marker of TCR priming affinity, and describe a novel way in which CD45RB status can functionally categorize the CD8+ T cell memory pool.
Mycobacterium tuberculosis stimulates neutrophil infiltration into the lungs through activation of S100A proteins in an early secreted antigenic target of 6-kDa dependent manner
Authors: Jung Bock-Gie , Adeniyi Biodun A. , Samten Buka 
Published: January 2023

Abstract
Health Science Center at Tyler Neutrophils infiltrate the lungs in active tuberculosis (TB) and contribute to the exacerbation of TB pathology. However, the contributing factors and the mechanisms of neutrophil infiltration in TB are unclear. As secretion of early secreted antigenic target of 6 kDa (ESAT-6) and its molecular partner culture filtrate protein 10 kD (CFP10) by ESX-1 secretion system is essential for pathogenesis of Mycobacterium tuberculosis (Mtb), we infected C57BL/6 mice intranasally with Mtb strains H37Rv, its esat-6 deletion mutant, and esat-6 complemented strain and evaluated lung neutrophil infiltration. H37Rv and esat-6 complemented strain induced neutrophil infiltration at day 7 and peaked at day 14 post infection. Whereas esat-6 deletion mutant induced significantly less neutrophil infiltration at both time points. In line with this, intranasal delivery of recombinant ESAT-6 but not CFP10 or Hank’s balanced salt solution (vehicle) induced neutrophil infiltration of the lungs as early as 2 hours, peaked at 24 hours, and started to decline at 72 hours post treatment. RNA-sequencing analysis of total lung RNA from ESAT-6 or CFP10 treated mice identified S100A9 as one of the most significantly upregulated genes by ESAT-6. Real-time PCR and ELISA validated that ESAT-6 stimulated increased gene expression and protein secretion of S100A9 in mouse lungs. Immunohistochemistry analysis revealed that ESAT-6 induced neutrophilic lung inflammation. Consistent with this, H37Rv and esat-6 complemented strain induced significantly higher levels of S100A9 compared to their esat-6 deletion mutant in mouse lungs after intranasal infection. We conclude that ESAT-6-induced S100A9 plays a critical role in lung neutrophil infiltrations in TB infection.
CARD9 adaptor molecule is indispensable for protection against Cryptococcosis
Authors: Campuzano Althea , Castro-Lopez Natalia , Martinez Amanda , Leopold Wager Chrissy M. , Wormley Floyd L. 
Published: January 2023

Abstract
Caspase recruitment domain-containing protein 9 (CARD9) is a critical adaptor molecule triggered by the interaction of C-type lectin receptors (CLRs) with carbohydrate motifs found in fungi. Cryptococcus neoformans is an opportunistic fungal pathogen predominantly affecting patients with suppressed T cell-mediated immunity and is responsible for ~15% of AIDS-related deaths globally. Cryptococcus can mask itself with a unique carbohydrate capsule complex which also serves as its predominant virulence factor. Previous studies have shown that immunization with a C. neoformans strain genetically engineered to express murine IFN-γ, H99γ, or a hyphaeforming mutant, LW10, results in protection against an otherwise lethal challenge with wild type (WT) C. neoformans. We therefore analyzed the role of CARD9 during the induction of protective anti-Cryptococcus immunity in WT and CARD9 knockout (KO) mice given an experimental pulmonary infection with Cryptococcus neoformans strain H99, H99γ or LW10. CARD9 KO mice were significantly more susceptible to C. neoformans infection compared to their WT counterparts. We then evaluated the role of pulmonary macrophages, the first line of defense against cryptococcosis. Pulmonary macrophages from CARD9 KO mice were unable to control fungal burden. These results suggest that CARD9-mediated signaling is required for optimal macrophage fungicidal activity against Cryptococcus. The overall goal of these studies is to define PRR/ligand interactions and downstream signal transduction pathways that are critical for the induction of protective immunity against cryptococcosis.
Human cytomegalovirus reprograms hematopoietic progenitor cells into immunosuppressive monocyte to achieve latency
Authors: Zen Ke 
Published: January 2023

Abstract
The precise cell type hosting latent human cytomegalovirus (HCMV) remains elusive. Here we report that HCMV reprograms human hematopoietic progenitor cells (HPCs) into a unique monocyte subset to achieve latency. Unlike conventional monocytes, this monocyte subset possesses higher levels of B7-H4, IL-10 and iNOS, longer lifespan and strong immunosuppressive capacity. Cell sorting of peripheral blood from latently infected human donors confirms that only this monocyte subset, representing less than 0.1% of peripheral mononuclear cells, is HCMV genome-positive but immediate-early (IE)-negative. Mechanistic studies demonstrate that HCMV promotes the differentiation of HPCs into this monocyte subset by activating cellular signal transducer and activator of transcription 3 (STAT3). In turn, this monocyte subset generates high level of nitric oxide (NO) to silence HCMV IE transcription and promote viral latency. By contrast, US28-knockout HCMV mutant incapable of activating STAT3, fails to reprogram the HPCs and achieve latency. Our findings reveal that HCMV differentiates human HPCs into long-life, immunosuppressive monocyte subset for viral latency via activating STAT3/iNOS/NO axis.
Novel M-CSF-producing γδ T cells protect against recurrent malaria
Authors: Mamedov Murad R. , Scholzen Anja , Nair Ramesh V. , Cumnock Katherine , Kenkel Justin A. , Oliveira Jose H. M. , Trujillo Damian L. , Saligrama Naresha , Zhang Yue , Rubelt Florian , Schneider David S. , Chien Yueh-hsiu , Sauerwein Robert , Davis Mark M. 
Published: January 2023

Abstract
In 2016, there were 216 million malaria cases – 445,000 of which resulted in deaths. Despite overwhelming evidence that γδ T cells strongly respond during malaria infection and vaccination, their functional and phenotypic characteristics remain the least understood facets of the adaptive immune response. Therefore, we studied the role of these cells in human and mouse malaria. In both Plasmodium falciparum-infected subjects and in P. chabaudi-infected mice, we found γδ T cells expanding rapidly after resolution of acute parasitemia, in contrast to αβ T cells that expanded at the acute stage and then declined. Silencing the murine γδ T cells led to recurrent rounds of Plasmodium parasitemia. Single-cell T cell receptor sequencing of the expanded mouse cells revealed oligoclonal γδ T cells restricted to the TRAV15N-1 (Vδ6.3) V-region and converging complementarity-determining region 3 (CDR3) motifs. Also, RNA-seq of the expanded γδ T cells showed an unexpected transcriptional profile characterized by myeloid-modulating factors, previously unseen in γδ T cells. The expanded TRAV15N-1 γδ T cells abundantly produced M-CSF, which was necessary for preventing parasitemic recurrence. Interestingly, αβ T cells were the major source of M-CSF during acute infection, while γδ T cells filled that role during the post-acute stage. We have uncovered a novel γδ T cell subset that fills a protective role in the late stage of malaria. These cells could provide the mechanism for other observed correlations between γδ T cell and myeloid activity in cancer and infectious disease.