bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced serum BCMA levels distinguish patients with primary antibody deficiency
Authors: Maglione Paul J. , Li Mingjie , Sanchez Eric , Radigan Lin , Chen Haiming , Berenson James R. , Cunningham-Rundles Charlotte 
Published: January 2023

Abstract
B-cell maturation antigen (BCMA) is a TNF family receptor that binds a proliferation inducing ligand (APRIL) and B cell activating factor (BAFF). BCMA is expressed by immunoglobulin secreting cells, but not other B cells, and supports their survival. Primary antibody deficiency (PAD) is the most common primary immunodeficiency and may lead to infection and complications including autoimmunity, enteropathy, lung disease, and malignancy. PAD patients with these complications have reduced survival, yet there are no validated tests to predict those at risk. We previously demonstrated that BCMA is present in the serum and its levels are elevated in patients with multiple myeloma. As BCMA is expressed by both normal and malignant antibody-producing cells, we examined serum levels of BCMA in PAD. Patients with PAD (n=68) had markedly reduced BCMA levels (median, 7.30) compared with healthy donors (n=119; median, 35.20; P &lt; 0.0001). When subgrouped based upon PAD diagnosis, serum BCMA was reduced compared to controls among those with common variable immunodeficiency (CVID) (n=48; median, 7.16; P &lt;0.0001) and X-linked agammaglobulinemia (n=8; median, 2.30; P &lt;0.0001), but not among those with selective IgA deficiency or hyper IgM syndrome. CVID patients with any inflammatory complication, or enteropathy specifically, had significantly lower serum BCMA than CVID patients without complications (P &lt; 0.01 for both). Serum BCMA moderately correlated with isotype-switched memory B cells (r = 0.473), but poorly correlated with IgA, IgG, or IgM levels or total B cell levels. These results demonstrate that reduced serum BCMA levels are found in PAD patients, distinguish types of PAD, and are associated with the development of complications in CVID.
Cysteine-cysteine chemokine receptor 5 (CCR5) profiling in HIV infected individuals attending Federal Medical Centre, Yenagoa, Bayelsa State.
Authors: Mirabeau Tatfeng Youtchou 
Published: January 2023

Abstract
Cysteine-cysteine chemokine receptor 5 (CCR5) is a protein found on the surface of CD4 cells which Human immunodeficiency virus (HIV-1) uses as a co-receptor when entering the host’s target cells. There is a variant of CCR5 known as CCR5 delta 32 that results due to a deletion mutation. CCR5 delta 32 plays an important role in the acquisition of HIV-1 and progression to AIDS. This study was done to determine the CCR5 genotype of HIV positive patients attending Heart to Heart clinic in Federal Medical Centre, Yenagoa, Bayelsa State. A total of 50 whole blood samples were collected by simple random sampling from 50 HIV positive patients attending Heart to Heart clinic in Federal Medical Centre, Yenagoa, Bayelsa State. DNA was extracted from each sample using ZR mini prep DNA extraction kit. CCR5 gene in each DNA extract was amplified by polymerase chain reaction on a 9700 ABI Thermo Cycler and then resolved on 1% agarose gel electrophoresis. Out of the 50 samples examined, 50 (100%) were homozygous for the normal CCR5 gene, 0(0%) were homozygous for the CCR5 delta 32 gene and no heterozygosity was recorded. This study revealed a very low or absence of CCR5 delta 32 deletion gene among HIV patients in Yenagoa suggestive of their rapid progression towards AIDS if other measures are not observed.
Age related changes in inflammatory and regulatory subsets within a healthy population are biased by CMV infection and oldest age.
Authors: Norton Elizabeth B 
Published: January 2023

Abstract
Age-related inflammation is detrimental to the host and plays a key initiator of disease. However, it is unclear how patterns of immune cells and particularly inflammatory and regulatory subsets occur within a healthy population. We investigated peripheral blood markers for immunologic subsets and inflammatory markers using samples collected from a local Blood Bank. 319 subjects between 25–81 years were included that had passed standard collection and infection status criteria. Batches of freshly collected whole blood samples were lysed and immediately processed for flow cytometry using 9-color panels of lymphocyte, myeloid, and platelet markers. Data was normalized by fold change to the young (25–35 yr) group included within batches (7 total) compared to older (36–45, 46–55, 56–64, or 65+ year) age groups. Overall donor age was significantly related to weight, blood pressure, and CMV seropositivity by Spearman’s correlation analyses. We observed few immunologic changes between age groups, except significant differences within the 56–64yr age group. These individuals expressed significantly higher levels of antigen-experienced CD45RO+ CD8 T-cells, regulatory TGF-beta+ CD4 T-cells, and plasma B-cells that correlated with CMV seropositivity. The 56–64 age group also expressed higher levels of non-classical monocytes and platelet monocyte aggregates, both related to inflammation. A lack of changes observed in the highest age group (65+) may be due to selection biases from earlier death and disease. Our data supports that responses to chronic viral infections like CMV may be a major regulator of healthy aging, and also reveals potential biases in recruited populations of older adults.
Transient antigen priming promotes B cells recruitment into humoral response or return to quiescence in vivo.
Authors: Grigorova Irina , Turner Jackson , Benet Zachary 
Published: January 2023

Abstract
Consistent with the Bretscher and Cohn’s two-signal model of lymphocyte activation, B cells must acquire antigen (Ag) via their B cell receptors (BCR), and then get help from cognate Th cells to initiate long-term antibody responses. Matzinger’s model then implied that for immune tolerance, BCR signaling in the absence of T cell help must lead to B cell anergy or death. This view has been supported by multiple in vivo studies of B cells continuously exposed to self-Ags. However, the fate of B cells transiently exposed to Ag in vivo is unclear. Intravital imaging suggested the transient dynamics of large particulate foreign Ags acquisition by B cells during the initial phase of immune response, but could not address whether such exposure is sufficient for B cell participation in the humoral response. In this study we show that in the presence of T cell help, transient single Ag acquisition promotes B cells’ recruitment into the germinal center, memory and plasma cell responses in vivo. We also demonstrate that transiently Ag-primed B cells do not undergo apoptosis in the absence of T cell help in vivo, but return to quiescence, and upon reacquisition of Ag and T cell help can mount a potent humoral response. Based on these findings we suggest a possibility of multiple cycles of Ag acquisition by B cells and return to quiescence. When T cell help is limiting, this mechanism may promote a greater diversity of B cell clones to enter the humoral response to foreign Ags. However, a failure of B cells to undergo anergy or apoptosis after a transient acquisition of self-Ags may contribute to breach of B cell tolerance.
NADPH oxidase-derived superoxide provides a third signal for CD4 T cell effector responses
Authors: Padgett Lindsey E , Tse Hubert Ming 
Published: January 2023

Abstract
Efficient T cell immune activation requires a synergistic interaction between innate immune-derived reactive oxygen species (ROS) and pro-inflammatory cytokines. Our laboratory previously demonstrated that in the absence of NADPH oxidase (NOX)-derived superoxide, autoreactive T cell responses were profoundly compromised. To examine the role of ROS deficiency on antigen-specific T cells in a non-autoimmune setting and further test the hypothesis that Th1 T cell responses would be diminished in the absence of ROS, we generated the OT-II.Ncf1m1J mouse containing superoxide-deficient, OVA323-339-specific CD4 T cells. Stimulation of OT-II.Ncf1m1J elicited a 4-fold decrease in IFN-γ (p&lt;0.05), concomitant with 2-fold reductions in CD4 T cell-derived IL-12Rβ2 and T-bet, required for Th1 activation. Th1 responses elicited by OVA323-339 stimulation were redox-sensitive, as addition of exogenous superoxide to OT-II.Ncf1m1J CD4 T cells restored IFN-γ synthesis and IL-12 signaling to approximately OT-II CD4 T cell levels. Conversely, Th1 responses were curbed in wild type OT-II T cells via free radical dissipation with a superoxide dismutase mimetic. This data highlights the importance of NOX-derived ROS in providing a third signal for adaptive immune maturation by modulating IL-12 signaling and may represent a promising therapeutic strategy in curbing CD4 T cell autoreactivity.
Glucocorticoids enhance neutrophil survival via G-CSF
Authors: Banuelos Jesus , Cao Yun , Shin Soon Cheon , Lu Nick 
Published: January 2023

Abstract
Glucocorticoids promote the survival of neutrophils, the mechanism of which is not clear. We found that glucocorticoids and proinflammatory cytokines synergistically induced G-CSF in primary human neutrophils and macrophages and multiple cell lines. The induction is at the transcriptional level and mediated by NF-κB and the glucocorticoid receptor as demonstrated by site-directed mutagenesis and ChIP assays. In both an LPS-induced airway inflammation model and a chronic OVA-induced airway inflammation model, BAL G-CSF, but not KC or IL-6, was resistant to glucocorticoid suppression. Glucocorticoids together with NF-κB inhibitors, but not either agent alone, decreased BAL G-CSF and neutrophils. Neutrophils from G-CSFR null mice, in contrast to those from wild type animals, were no longer protected by glucocorticoids. Furthermore, knockdown of G-CSF abolished the ability of BEAS 2B bronchial epithelial cells to protect neutrophils from spontaneous apoptosis. These data identify G-CSF as a potential target to increase glucocorticoid sensitivity in neutrophil-driven inflammatory conditions such as chronic obstructive pulmonary disease and neutrophil-dominant endotypes of asthma.
The AIM2-like receptors are dispensable for activation of the interferon stimulatory DNA (ISD) pathway.
Authors: Gray Elizabeth , Stetson Daniel B 
Published: January 2023

Abstract
Detection of intracellular DNA triggers activation of the STING-dependent interferon-stimulatory DNA (ISD) pathway, which is essential for antiviral immune responses; on the other hand, inappropriate immune responses to self DNA result in autoimmunity. Multiple DNA sensors have been proposed to activate the ISD pathway, including cyclic GMP-AMP synthase (cGAS) and a family of DNA binding receptors called the AIM2-like receptors (ALRs). Analysis of cGAS-deficient mice has revealed that cGAS is a key DNA sensor that is required for activation of the ISD pathway; however, whether the ALRs contribute to this pathway remains unclear.
Here, we generated mice lacking all 13 mouse ALR genes as a novel tool to explore the function of the ALRs. We show that all ALRs are dispensable for the type I interferon (IFN) response to transfected DNA ligands, DNA virus infection, and lentivirus infection. We also show that the DNA sensor cGAS, but not the ALRs, is required to drive autoimmune disease in the Trex1-deficient mouse model of Aicardi-Goutieres Syndrome. Finally, we used CRISPR to disrupt the human AIM2-like receptor IFI16 in primary human fibroblasts and show that IFI16 is dispensable for the IFN response to transfected DNA ligands as well as human cytomegalovirus (HCMV) infection. Thus, our data reveal that ALRs are dispensable for activation of the ISD pathway and demonstrate that cGAS is the primary DNA sensor that drives the IFN response to DNA.
TNFAIP8 variant 2 has an anti-inflammatory role in Toll like Receptor 4 signaling
Authors: Lowe Julie Marie , Menendez Daniel , Resnick Michael A , Fessler Michael B 
Published: January 2023

Abstract
The cell response to pathogens involves complex signaling that affects expression of thousands of genes. Characterization of the regulation and function of these genes is critical since failure of this response can foster the development of chronic disorders. In a high-throughput microarray analysis of human macrophages stimulated with the TLR4 ligand LPS, we found high and rapid induction of Tumor Necrosis Factor-a-Inducible Protein-8 (TNFAIP8), a poorly defined gene proposed to regulate cell fate. While very little is known about TNFAIP8 expression and function, recent studies of murine Tnfaip8 suggest a role in antibacterial immunity and inflammation. Our analysis of human TNFAIP8 revealed two previously uncharacterized expression variants (v1 and v2) that possess distinct predicted functional domains. Primary human macrophages predominantly express v1, whereas a panel of human cancer cell lines displayed a marked v2 predominance. Interestingly, we found that v1 and v2 are both induced by LPS in macrophages, but with different kinetics, suggesting that they may have distinct functions in innate immunity. Selective depletion of v2 in A549 cells dramatically enhanced the baseline expression of several pro-inflammatory cytokines including IL-6, IL-8 and IL-1b. Furthermore, in response to LPS, v2-depleted cells had increased induction of IL-8, IL-1b, and TNFa. Together, these data suggest that TNFAIP8 v2 has an anti-inflammatory role in resting and TLR ligand-stimulated cells. Work is currently underway to determine 1) the molecular mechanisms of the anti-inflammatory role of TNFAIP8, for example, whether NF-kB activation is altered by v2 depletion; and 2) whether v1 has a distinct role in immune signaling.
Comprehensive RNAi-based screening of human and mouse TLR pathways identifies species-specific preferences in signaling protein use
Authors: Sun Jing , Li Ning , Oh Kyu-Seon , Dutta Bhaskar , Vayttaden Sharat J , Lin Bin , Ebert Thomas S , De Nardo Dominic , Davis Joie , Bagirzadeh Rustam , Lounsbury Nicolas W , Pasare Chandrashekhar , Latz Eicke , Hornung Veit , Fraser Iain 
Published: January 2023

Abstract
Toll-like receptors (TLRs) are a major class of pattern recognition receptors, which mediate the responses of innate immune cells to microbial stimuli. To systematically determine the roles of proteins in canonical TLR signaling pathways, we conducted an RNA interference (RNAi)–based screen in human and mouse macrophages. We observed a pattern of conserved signaling module dependencies across species, but found notable species-specific requirements at the level of individual proteins. Among these, we identified unexpected differences in the involvement of members of the interleukin-1 receptor–associated kinase (IRAK) family between the human and mouse TLR pathways. Whereas TLR signaling in mouse macrophages depended primarily on IRAK4 and IRAK2, with little or no role for IRAK1, TLR signaling and pro inflammatory cytokine production in human macrophages depended on IRAK1, with knockdown of IRAK4 or IRAK2 having less of an effect. Consistent with species-specific roles for these kinases, IRAK4 orthologs failed to rescue signaling in IRAK4-deficient macrophages from the other species, and only mouse macrophages required the kinase activity of IRAK4 to mediate TLR responses. The identification of a critical role for IRAK1 in TLR signaling in humans could potentially explain the association of IRAK1 with several autoimmune diseases. Furthermore, this study demonstrated how systematic screening can be used to identify important characteristics of innate immune responses across species, which could optimize therapeutic targeting to manipulate human TLR-dependent outputs.
Pattern recognition channels in anti-viral host defense in humans and an insect vector
Authors: Carrithers Michael D 
Published: January 2023

Abstract
A novel mechanism of innate immune signaling is proposed. The central hypothesis is that viral-associated molecular patterns directly activate intracellular splice variants of voltage-gated sodium channels to increase transcription of anti-viral genes. Past work revealed that splice variants of human voltage-gated sodium channels are expressed intracellularly on endosomes and contain exon deletions that alter channel kinetics.
Here it is shown that intracellular dsRNA activates the human macrophage SCN5A variant to initiate a signaling cascade that leads to increased transcription of type I interferons and SP100-related genes. This pathway is regulated by sequential downstream activation of a calcium-dependent adenylate cyclase, adcy8, and the cyclic AMP-dependent transcription factor ATF-2. Knockdown of channel expression in human macrophages reduces the host response to HSV-1.
Additional work reveals expression of an evolutionarily related sodium channel gene, AAEL006019, in Aedes aegypti, the yellow fever mosquito. This intracellular channel contains an alternative exon deletion that reduces peak current but does not alter ion selectivity. In contrast to human macrophage SCN5A, the AAEL006019 channel is activated by mimics of virally-derived ssRNA, but not dsRNA. Channel activation increases transcription of mediators of insect innate immunity, RelA and Ago2.
These data suggest that channel variants initiate anti-viral responses independently of other pattern recognition receptor pathways. It is postulated that pattern recognition by channel variants are an evolutionarily conserved mechanism of innate immune signaling that reflect a complex interplay between human host, vector, and virus.
Isoforms of ADAR1 independently control MDA5-driven autoimmunity and multi-organ development
Authors: Pestal Kathleen , Funk Cory C , Snyder Jessica M , Price Nathan D , Treuting Piper M , Stetson Daniel B 
Published: January 2023

Abstract
Mutations in the ADAR gene that encodes the ADAR1 RNA editing enzyme cause Aicardi-Goutières Syndrome (AGS), a severe autoimmune disease associated with an aberrant type I interferon response. How ADAR1 prevents autoimmunity remains incompletely defined. Here, we demonstrate that ADAR1 is a specific and essential negative regulator of the MDA5-MAVS RNA sensing pathway. Moreover, we uncovered a MDA5-MAVS-independent function for ADAR1 in the development of multiple organs. We showed that the p150 isoform of ADAR1 uniquely regulated the MDA5 pathway, whereas both the p150 and p110 isoforms contributed to development. Abrupt deletion of ADAR1 in adult mice revealed that both of these functions were required throughout life. Our findings delineate genetically distinct roles for both ADAR1 isoforms in vivo, with implications for the human diseases caused by ADAR mutations.
Elucidating regulatory mechanisms of RAG2 in response to DNA damage.
Authors: Byrum Jennifer , Rodgers William , Rodgers Karla 
Published: January 2023

Abstract
V(D)J recombination of lymphocyte antigen receptor genes occurs via the formation of DNA double strand breaks (DSBs) through the activity of RAG1 and RAG2. The co-existence of RAG-independent DNA DSBs generated by genotoxic stressors potentially increases the risk of incorrect repair and chromosomal abnormalities. However, it is not known whether cellular responses to DSBs by genotoxic stressors affect the RAG complex. Using cellular imaging and subcellular fractionation approaches, we show that formation of DSBs by treating cells with DNA damaging agents causes export of nuclear RAG2. Within the cytoplasm, RAG2 exhibited substantial enrichment at the centrosome. Further, RAG2 export was sensitive to inhibition of ATM, and was reversed following DNA repair. Live cell imaging reveals export of RAG2 within minutes of DNA damage, demonstrating a rapid response to genotoxic stress. Intriguingly, dose response assessment exhibited RAG2 export following the generation of very few DNA DSBs, indicating that DNA damage-triggered export of RAG2 can occur under normal physiological conditions. The core region of RAG2 was sufficient for export, but not centrosome targeting, and RAG2 export was blocked by mutation of Thr490. In summary, DNA damage triggers relocalization of RAG2 from the nucleus to centrosomes, suggesting a novel mechanism for modulation of cellular responses to DSBs in developing lymphocytes.
Relative contribution of medullary thymic epithelial cells and dendritic cells to thymocyte central tolerance as assessed by multi-photon microscopy
Authors: Ehrlich Lauren Ilyse Richie , Lancaster Jessica N , Hu Zicheng , Tran Andy , Sasiponganan Chayanit 
Published: January 2023

Abstract
Following positive selection, thymocytes migrate into the medulla where they encounter diverse tissue-restricted antigens (TRAs) that induce self-tolerance. Both medullary thymic epithelial cells (mTECs) and dendritic cells (DCs) present TRAs to induce negative selection of autoreactive thymocytes, but their relative contribution remains unresolved. Previous studies using genetic models to impair antigen presentation by mTECs or DCs demonstrated both cell types could induce negative selection. However, because interactions between thymocytes and stromal cells maintain a properly differentiated stromal compartment, these studies may not reflect physiologic interactions or relative contributions of mTECs and DCs when both are intact. Thus, we developed a 2-photon microscopy approach to directly observe interactions between thymocytes and DCs or mTECs during negative selection, while monitoring T cell receptor (TCR) activation. Despite earlier studies indicating DCs are required for negative selection to a soluble TRA, we find that mTECs and DCs contribute equivalently to TCR stimulation of CD4 and CD8 single positive (SP) thymocytes responding to membrane-bound or secreted TRAs. Interactions with mTECs and DCs generally accounted for all TCR activation events; however, a significant fraction of CD4SP activation events were not accounted for in response to a soluble TRA, suggesting presentation by other medullary stromal subsets. Initial analysis of polyclonal thymocytes also indicates equal contributions of mTECs and DCs to medullary TCR activation. In summary, mTECs and DCs contribute equivalently to presentation of soluble and membrane-bound mTEC-expressed TRAs on MHC-I and MHC-II during negative selection.
The role of nutrients in B lymphocyte growth and survival responses.
Authors: Heyse Shannon A , Connolly Timothy , Chiles Thomas Crane 
Published: January 2023

Abstract
B cell activation is an energetically demanding process during which B lymphocytes shift from a resting state to a proliferative, metabolically active state. Little is known about the metabolic reprogramming process or the role extracellular nutrients play in the activation response. We demonstrate that there are distinct requirements for the nutrients L-glutamine and glucose during activation. We show that cells activated in glucose-depleted conditions are still able to undergo growth and signaling events. In contrast, we show that extracellular L-glutamine is essential for all but the earliest activation events, and cells cultured in L-glutamine-deprived conditions are unable to enter the cell cycle. Consistently, we show that extracellular supplementation of the cell-permeable derivative of a-ketoglutarate (a-KG) is able to rescue cell activation in the absence of glutamine. We also show the induction of the high affinity amino acid transporter ASCT2 is required for glutamine uptake following BCR crosslinking. Specifically, we found that halting glutamine uptake or processing by inhibiting ASCT2 or the glutaminolytic enzyme glutaminase causes activation defects that parallel those observed in glutamine deprived conditions, indicating a requirement for glutaminolysis during the very early stages of activation. Finally, we found that a-KG does not contribute to epigenetic remodeling, but is necessary for mTORC1 activation. In turn, mTORC1 activity is required for upregulation of the glucose transporter Glut1 during activation, as well as increased glucose uptake. These findings indicate a distinct metabolic profile that begins with glutamine uptake, and acts through mTORC1 signaling to later promote glucose uptake.