bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflammatory markers in relation to pre-pubertal obesity
Authors: Dinov Darina , Khait Albert
Published: January 2023

Background

According to the WHO, current childhood obesity trends are expected to increase to 70 million by 2025. Childhood obesity is becoming a major epidemic with adipokines-TNF-α, IL-6, leptin, and adiponectin-being potentially implicated in the pathogenesis.

Methods

We conducted a literature search of PubMed clinical trials and articles where we searched key terms: ‘pre-pubescent obese children’ cross referenced with ‘TNF-α’ or ‘IL-6’ or ‘hs-CRP’ or ‘adiponectin’.

Research

Thirty-six articles remained in the review after our exclusion criteria was applied. Most of these showed a positive correlation of obesity with TNF-α, IL-6, and hs-CRP. In addition, the research showed a negative correlation with adiponectin. There was one study that we found that showed TNF-α to not be related to obesity and another that showed adiponectin to have a positive correlation rather than negative correlation with obesity. Another contributing study that we evaluated showed that TNF-α causes a decrease in C/EBP-alpha which are gene promoters that downregulate myc. By downregulating this cell cycle regulator there is potential for proliferation of cells leading to increased risk for both obesity and cancer. TNF-α, is one of the primary inflammatory markers that has been implicated in obesity; thus, showing that it could have diagnostic factors in cancer through this downregulation of myc.

Conclusion

A possible consideration for future research is to evaluate the possible relationship between inflammatory markers discussed as diagnostic factors for pediatric cancer. With this potential innovative method, we as a research community can lessen the burden cancer has put on our society.
Induction of class-switched and somatically hypermutated primary and anamnestic antibody responses by TLR-BCR co-engagement in Tcrβ
−/−
Tcrδ
−/−and NSG/B-cell mice
Authors: Rivera Carlos Eduardo , Li Xin , Yan Hui , Chupp Daniel , Taylor Julia , Zan Hong , Xu Zhenming , Casali Paolo
Published: January 2023

Ig gene CSR/SHM as well as plasma cell and memory B cell differentiation are central processes to the maturation of the antibody response and generally depend on T cell help. Prompted by our findings that CSR is efficiently induced by T cell-independent (TI) stimuli in vitro, e.g., dual engagement of TLR/BCR, here we have addressed the induction of TI antibody responses and underlying mechanisms in vivo using Tcrβ−/−Tcrδ−/− mice. These mice lack T cells and, as expected, failed to generate any class-switched antibodies to T-dependent antigens (e.g., NP-CGG and ovalbumin), even in the presence of adjuvants. They, however, displayed circulating IgG2b, IgG3 and IgA, at levels comparable to those in C57BL/6 mice, and to a lesser extent, IgG1 and IgG2a. Further, they generated high-affinity NP-specific IgG2b and IgG3 upon immunization with NP-LPS, but not NP-Ficoll mixed with LPS. The anti-NP-LPS response entailed a high-frequency of (replacement) mutations in the Ig variable region, a hallmark of antibody affinity maturation, CSR and generation of a high number of NP-binding IgG+B cells. Also generated at a high frequency were IgG+NP-specific plasma cells, which homed to the bone marrow, and memory B cells, which were instrumental in mounting an effective anamnestic response. These findings, together with the readily detectable NP-specific response to NP-LPS in immune-deficient NSG mice grafted with highly purified B cells, highlight a previously unsuspected but efficient TI and B cell-intrinsic mechanism, i.e., TLR/BCR co-engagement, in the generation of full-fledged antibody responses. The B cell-intrinsic nature of this mechanism was further emphasized by the failure of mice with B cell-specific Tlr4 deficiency to respond to NP-LPS.
Hepatic CD1d+ B cells reduce immune-mediated drug-induced hepatitis in male BALB/c mice and account for sex bias in hepatitis severity seen in this disease
Authors: Njoku Dolores B. , Nyandjo Maeva , Hamad Abdu , Cottagiri Merylin
Published: January 2023

Sex modulates severity in autoimmune diseases. In susceptible individuals, drug metabolites induce hepatitis, autoimmunity and liver injury. Drug–induced hepatitis (DIH) is a leading cause of liver failure and is a common reason an approved medication is removed from the consumer market. We previously showed that estrogen and IL-6 promote sex bias by increasing hepatitis severity and by reducing IL-10 and Foxp3+ regulatory T cells in female BALB/c (WT) mice. We also found antibody-independent roles for sex bias via IL-10 and CD1d+B cells in male WT mice with reduced hepatitis. To directly assess the significance of CD1d+B cells in male WT mice with DIH, we induced hepatitis in male and female WT mice and treated them with anti-CD20 after 2 weeks at clinically relevant doses used for treating B cell-associated autoimmune diseases. Hepatitis was induced in female and male WT mice by immunizing them with cytochrome P4502E1 (CYP2E1) epitopes modified by drug metabolites. Splenic and hepatic B cells as well as hepatitis were assessed. Groups were analyzed using Mann-Whitney U. A p value < 0.05 was significant. We found reduced hepatitis in male when compared to female WT mice associated with elevated hepatic follicular CD21/CD35+IgM-B cells (p<0.01) and elevated hepatic and splenic CD1d+B cells (p<0.001) as well as reduced splenic marginal zone CD21/CD35+ IgD+ CD23− B cells in male mice (p<0.05). Anti-CD20 did not abolish sex bias in splenic CD1d+B cells (p<0.05) but reduced hepatic CD1d+B cells (p<0.01), abolished sex bias in the expression of splenic marginal zone B cells and increased DIH in male WT mice (p<0.05). We demonstrate protective roles for hepatic CD1d+B cells in sex bias and in the reduction of hepatitis in male WT mice.
Human germinal center B cells are intrinsically able to discriminate antigen affinity and with T cell help express plasma cell transcription factors
Authors: Saniee Avva , Kwak Kihyuck , Quizon Nicolas , Sohn Haewon , Manzella-Lapeira Javier , Holla Prasida , Lu Jinghua , Xie HengYi , Xu Chenguang , Spillane Katelyn , Tolar Pavel , Pierce Susan K.
Published: January 2023

The selection of GC B cells that express high affinity B cell receptors (BCRs) is driven by the ability of B cells to both signal through the BCR and to extract antigen and present it to follicular helper T cells (T FH cells). Using anti-kappa antibodies of low (KD=3.9×10 −7 ) versus high (KD=2.4×10 −9 ) affinities attached to membranes as surrogate antigens, we show that LZ GC B cells are able to discriminate between these and responded only to the high affinity antigen. In contrast, naïve B cells responded to both high and low affinity antigens. LZ GC B cells engaged membrane associated surrogate antigens through highly dynamic F-actin and ezrin-rich pod-like structures that concentrated BCRs at their contact points. Using DNA-based mechanical force nano-sensors we observed robust pulling forces localized to the contact sites of the pods with the membrane. In contrast, naïve B cells formed flat stable contacts with the membranes and showed only defuse weak pulling forces. GC B cells optimally express transcription factors that drive plasma cell differentiation, namely IRF-4 and PRDM-1, in response to antigen in combination with T FH help while naïve B cells increased IRF-4 and PRDM-1 transcription in response to T FH alone and less so to antigen alone. Thus, LZ GC B cells appear to be intrinsically capable of antigen affinity discrimination and with the acquisition of T FH help BCR-activated LZ GC B cells differentiate into plasma cells.
B lymphocytes are a major source of IL-27 that drives class-switched antibody responses and anti-viral immunity through paracrinic targeting of B cells and T follicular helper cells
Authors: Yan Hui , Wang Rui , Fernandez Maria , Rivera Carlos Eduardo , Sanchez Helia , Li Xiao-Dong , Zhang Nu , Zan Hong , Meng Xiang-Zhi , Kedl Ross , Hunter Christopher A. , Xiang Yan , Casali Paolo , Xu Zhenming
Published: January 2023

In addition to generating antibodies against infections, B lymphocytes produce cytokines to regulate immune functions. Here, we have identified B cells as a major source of cytokine IL-27 (the heterodimer of IL-27p28 and EBI3) by using B cell-deficient mMT and JH mice, mice with B cell-specific deficiency in Ebi3 and NSG mice transplanted with highly purified B cells. IL-27 in turn targets B cells to undergo class-switching to IgG2a, as shown by decreased antigen-specific IgG2a in mice with B cell-specific deficiency IL-27 receptor signaling, leading to defective clearance of vaccinia virus infection. The paracrinic function of IL-27 is recapitulated in vitro by B cell production of IL-27 upon stimulation by a TLR ligand together with CD154 (CD40 ligand) and IL-21, two hallmark stimuli of TFH cells, and IL-27 induction of T-bet and a gene signature similar to that induced by IFNγ, IL-27 collaboration with IFNγ in inducing T-bet and IgG2a, and, finally, selective switching to IgG2a in primed B cells when mixed with IL-27-producing B cells, which display a metabolic program distinct from that in IL-27-responding B cells, i.e., heightened TCA cycle activities and enhanced lactate generation and glutaminolysis. B cell-produced IL-27 also promotes differentiation of TFH cells, as shown by reduced number of TFH cells and defective IL-21 expression in residual TFH cells in mice with B cell-specific deficiency in Ebi3 and, consequently, severe impairments in the germinal center development, class-switching to all Ig isotypes and protective antibody responses to vaccinia virus infection in these mice. Overall, B cell production of IL-27 is a previously unrecognized important regulatory mechanism in the antibody response and anti-viral immunity.
Marijuana THC treatment led to decreased metabolic functions of Staphylococcal enterotoxin B-activated lymphocytes
Authors: Mohammed Amira K. , Alghetaa Hasan F. , Nagarkatti Prakash S. , Nagarkatti Mitzi
Published: January 2023

Studies from our laboratory have shown that Δ9-Tetrahydrocannabinol (THC), an ingredient found in marijuana plant Cannabis sativa, can attenuate acute lung injury induced by Staphylococcus enterotoxin B (SEB). In the current study, we investigated the role of THC on the metabolism of SEB-activated lymphocytes. To this end, we determined metabolic potential of SEB-activated lymphocytes treated with vehicle or THC by performing the Cell Mito Stress Test. The oxygen consumption rate (OCR) in THC-treated cells was decreased when compared to vehicle-treated group whereas the extracellular acidification rate (ECAR) was similar in both the groups. Specifically, electron transport chain inhibitors namely, oligomycin, FCCP and rotenone+antimycinA were added to measure ATP-linked respiration, maximal respiration and non-mitochondrial respiration, respectively. THC treatment led to a significant decrease in the basal respiration, ATP production, proton (H+) leak, maximal respiration, spare respiratory capacity and nonmitochondrial respiration. We also performed the Mito Fuel Flex assay to measure the dependency, capacity and flexibility of cells to oxidize glucose, glutamine and fatty acids. Treatment with inhibitors, BPTES and etomoxir showed a decline in the OCR in SEB+vehicle treated cells demonstrating that glutamine and/or fatty acids serve as major source of fuel in these cells when compared to SEB+THC treated group. However, when UK5099 was added, THC- and vehicle-treated cells showed a reduced response thereby indicating that glucose dependency was similar in both the groups. Together, THC modulates metabolic functions of activated lymphocytes which may affect their signaling, differentiation and toxicity.
Modulation of inflammatory responses in heart failure via activation of alpha-7 nicotinic acetylcholine receptor agonist GTS-21
Authors: Mai Xuyen Kim , Kha Mindy , Chow Sheryl , Cameron Joshua , O’Barr Stephen A.
Published: January 2023

Heart failure (HF) is a prominent health concern amongst the public with prevalence rate being over 5.8 million in the USA. Inflammation and cytokine signaling are two main factors that lead to the pathogenesis of HF because of their effects on the heart and peripheral circulation. The “smoker’s paradox” showed associations between improvements in short-term acute myocardial infarction (MI) and smokers via activation of α7 nicotinic acetylcholine receptor (α7 nAChR) that can inhibit inflammatory responses in HF. Studies showed that the vagus nerve can modulate these inflammatory responses by activating the cholinergic anti-inflammatory pathway via stimulation of α7 nAChR. Hence, stimulation of α7 nAChR with specific agonists can be a potential therapeutic target for HF because it can inhibit pro-inflammatory responses. In this study, the anti-inflammatory effects of 3-(2,4-dimethoxybenzylident)-anabaseine (GTS-21), a partial agonist of α7 nAChR, were observed in an in vivo zebrafish model for HF. For four consecutive days, the zebrafishes were pre-treated with GTS-21 (0.113 μM) for 20 minutes per day. On the fourth day after pre-treatment with GTS-21, the zebrafishes were induced with MI by oligo-[2-(2-ethoxy)- ethoxyethyl)-guanidinium-chloride] (PGH) and survival was recorded. Using reverse transcription PCR (rt-PCR) for analysis, results showed that pre-treatment with GTS-21 modified the gene regulatory protein levels and reduced cytokine expression in the myocardium tissue. Other α7 nAChR agonists were investigated for their potential therapeutic effect in inhibiting inflammatory responses, but GTS-21 was more efficacious in inhibiting cytokine expression. Thus, GTS-21 may be used as a novel therapeutic for HF.
The response of CD8 T cells to antigenic stimulation is controlled by their endogenous circadian clock
Authors: Nobis Chloé , Dubeau-Laramée Geneviève , Cermakian Nicolas , Labrecque Nathalie
Published: January 2023

Circadian clocks control various aspects of the immune system in mammals but their role in the adaptive immune response remains poorly defined. Our previous work showed that the CD8 T cell response to vaccination with dendritic cells loaded with the OVA peptide (DC-OVA) varies according to the time of day. In this study, we have identified the clock involved in the in vivo CD8 T cell response and have started to uncover how the circadian clock affects this response. Using Kb-OVA tetramer staining, we found that the higher expansion of OVA-specific CD8 T cells in response to DC-OVA vaccination done in the middle of the day is abolished when CD8 T cells are deficient for the essential clock gene Bmal1. Similarly, the rhythm of cytokine production by CD8 T cells was abolished. Moreover, the observed rhythm impacts the ability to control an infectious challenge (by Listeria monocytogenes) as shown by a day/night variation in bacterial load in WT but not CD8 T cell-specific Bmal1 KO mice. In contrast, the rhythm of CD8 T cell response was not affected when Bmal1 KO DCs were used to vaccinate mice, confirming the role of the CD8 T cell clock in this rhythm. To assess whether the circadian clock affected the magnitude of the CD8 T cell response by modulating the affinity of the T cells recruited in the response, we measured CD8 T cell sensitivity to restimulation with various doses of OVA peptide. A stronger T cell expansion in response to antigen presentation correlated with an increased EC50, suggesting that the CD8 T cell clock acts by recruiting CD8 T cell clones bearing TCR with different affinities for the antigen. In conclusion, the CD8 T cell clock is essential for the rhythm of the CD8 T cell response and affects the affinity of the antigen-specific CD8 T cell response.
Neuroprotective roles of fractalkine in multiple sclerosis: Characterization of novel humanized animal model
Authors: Cardona Sandra M. , Kim Sangwon V. , Torres Vanessa , Hung Chiung-Yu , Church Kaira , Cleary Ian , Mendiola Andrew S. , Saville Stephen , Watowich Stephanie S. , Parker-Thornburg Jan , Littman Dan R. , Ransohoff Richard M. , Cardona Astrid E.
Published: January 2023

Multiple sclerosis (MS), an inflammatory demyelinating disease of the CNS is the leading cause of nontraumatic neurological disability in young adults. Immune mediated destruction of the myelin and oligodendrocytes are considered its primary pathology, but progressive axonal loss is the major cause of neurological disability. In an effort to understand microglia function in CNS inflammation, our laboratory showed that Fractalkine/CX3CR1 signaling regulates microglia neurotoxicity during neurodegeneration.

Fractalkine (FKN), a transmembrane chemokine expressed in the CNS by neurons signals through its unique receptor, CX3CR1 present in microglia. During EAE, CX3CR1 deficiency confers exacerbated disease, severe inflammation and neuronal loss. The CX3CR1 human polymorphism I249/M280 present in ~20% of the population exhibits reduced adhesion for FKN conferring defective signaling whose role in microglia function and effect on neurons during MS remains unsolved.

The aim of this study is to assess the effect of weaker signaling through hCX3CR1I249/M280 during EAE. We hypothesize that dysregulated microglial responses in absence of CX3CR1 signaling enhance neuronal/axonal damage.

We generated an animal model replacing the mouse CX3CR1 locus for the hCX3CR1I249/M280 variant. Upon EAE induction, these mice exhibit exacerbated EAE defined by severe inflammation and neuronal loss. We also observed that mice with aberrant CX3CR1 signaling are unable to produce FKN and CNTF during EAE as WT mice. Our results provide validation of defective function of the hCX3CR1I249/M280 variant and the foundation to broaden the understanding of microglia dysfunction during neuroinflammation.
ADAMTS7 extracellular matrix enzyme expression is required for optimal influenza-specific CD8+T cell immunity.
Authors: Stambas John , McMahon Meagan , Ye Siying , Dlugolenski Daniel , Tripp Ralph A. , McCulloch Daniel
Published: January 2023

Extracellular matrix (ECM) enzymes including the ADAMTS (A disintegrin-like and metalloproteinase with thrombospondin-1 motifs) family have been shown to regulate influenza-specific immunity. ADAMTS7, a largely uncharacterised ECM enzyme with broad tissue distribution has been associated with coronary heart disease and arthritis, however its role in viral immunity remains undefined. We assessed the contribution of ADAMTS7 to influenza-specific immunity using Adamts7−/− mice. Adamts7−/− mice intranasally infected with influenza virus showed increased weight loss and had higher viral loads when compared to WT controls. We also observed fewer influenza-specific CD8+ T cells and changes in cytokine production following primary and secondary infection suggesting ADAMTS7 expression is a key regulator of viral immunity.
Influenza-Induced Interferon-γ Promotes Alveolar Macrophage Depletion during Secondary Pneumococcal Infection
Authors: Bansal Shruti , Yajjala Vijaya Kumar , Bauer Christopher , Sun Keer
Published: January 2023

Secondary bacterial pneumonia is a significant cause of influenza-associated morbidity and mortality. Animal studies have shown that this viral/bacterial synergy is due to suppression of antibacterial immunity by influenza-induced cytokines, i.e., type I IFN and IFN-γ. However, it is not clear which of these pathways is most critical in the pathogenesis. In this study, we have performed comparative analyses of antibacterial immunity in type I IFN receptor-1 (IFNAR1)−/−, IFN-γ−/− and WT mice super-challenged with S. pneumoniae on day seven after PR8 infection. While nearly all WT and IFNAR1−/− mice succumbed, IFN-γ−/− animals fully survived from PR8/S. pneumoniae coinfection. In agreement, despite a temporary reduction at 24 h, lung bacterial burden in IFNAR1−/− mice was comparable to WT controls at 72 h after coinfection. At the same time, bacterial burden diminished in IFN-γ−/− mice. Rather than attenuated inflammatory cytokine response or neutrophil recruitment, the heightened bacterial burden is consistent with diminished alveolar macrophage (AM) numbers in IFNAR1−/− and WT mice after coinfection. Furthermore, we have used “macrophages insensitive to IFN-γ” (MIIG) mice, which express a dominant negative mutant IFN-γ receptor (IFN-γR) in macrophage lineage cells, to examine the direct effect of IFN-γ on macrophages. Similar to IFN-γR−/− mice, MIIG mice exhibited significantly increased AM numbers and bacterial clearance compared with WT controls at 72 h, as well as complete survival from coinfection. Together, these results indicate that by acting directly on macrophages/monocytes to reduce AM survival, IFN-γ plays a predominant role in inhibiting antibacterial immunity during post-influenza pneumococcal infection.
Keratinocytes affect biology of Langerhans cells through mRNA transfer
Authors: Su Qingtai , Igyártó Botond
Published: January 2023

Dendritic cell (DC) subsets might acquire specific immune functions based on their tissue of residence. Langerhans cells (LCs), a specific DC population located in the epidermis, are in close contact with epidermal keratinocytes (KCs), providing us with an easily accessible model to dissect the effect of epithelial cells on infiltrating DCs. Using microarray analysis, RT-qPCR, histology and flow cytometry, we showed that many of the KC-specific molecules, such as keratins and adhesion molecules, can be detected in LCs at mRNA and protein levels. To determine whether these KC-specific genes are accessible for transcription in LCs, we performed ATAC-seq on flow-purified LCs. We found that chromatin loci of these genes were in the closed conformation in LCs. Therefore, these data support the active transport of mRNAs from the KCs to LCs. Furthermore, we also showed that KC-specific expression of Cre, driven by the KRT14 promoter, can lead to genetic recombination and expression of YFP in the LCs. Additionally, YFP+ LCs could be readily identified in LC-depleted KRT14-YFP mice reconstituted with WT bone marrow, which further supports the material transfer from KCs to LCs. Of note, we found that tunneling nanotubes could be one of the potential mechanisms mediating the material transfer. The transfer of material between epithelial cells and epithelia-associated DCs was not limited to mice or to KC-to-LC transfer.

Taken together, these data suggest that the epithelial environment might have a long-term effect on DC biology and that genetic tools specifically targeting epithelial cells also affect tissue-resident immune cells, which adds another layer of complexity to data interpretation.
Prohibitin-1 and -2 have diverse cell-autonomous effects on inflammatory signaling
Authors: Psaltis Christine E. , Aloor Jim , Reece Sky W. , Kilburg-Basnyat Brita , Robidoux Jacques , Fessler Michael , Anderson Ethan , Gowdy Kymberly
Published: January 2023

Prohibitins (PHB1 and PHB2) are proteins that assemble in hetero-oligomeric complexes within the mitochondrial inner membrane and in the plasma membrane lipid rafts where they are at the nexus of metabolic and pro-survival decisions including inflammation. We have recently observed that mice intraperitoneal (i.p.) injected with lipopolysaccharide (LPS) have increased serum prohibitin (PHB), and injection of recombinant PHB1 (rPHB1) post LPS rescues cardiac function. However, the role of PHB in the innate immune response to LPS is currently unknown. Using an in vivo model of sepsis, we injected C57Bl/6J mice i.p. with LPS and 3 subsequent doses of rPHB1. Blood was analyzed for immune cell characterization by flow cytometry, and liver, kidney and lung tissue were harvested for pro-inflammatory cytokine expression. Systemic LPS increased number of blood neutrophils (PMNs), PMN expression of the adhesion molecule CD11b, and tissue expression of TNF-α, IL-6, and IL-1β. Treatment with rPHB1 decreased blood PMN CD11b expression and expression of IL-6 in liver, kidney and lung tissues. To better characterize the role of PHB in immune cells, we knocked down PHB1 or PHB2 in RAW 264.7 macrophages. PHB1- or PHB2-deficient macrophages were then stimulated with LPS, and cell supernatant and lysate were collected for cytokine production. Cell lines deficient in PHB2 had decreased TNF-α compared to macrophages sufficient in PHBs. These data suggest PHB1 and -2 have differential and complex effects on the innate immune response. Cell-associated PHB is required for acute pro-inflammatory signaling responses to LPS that initiate the sepsis response, but extracellular PHB, released in the later phase of sepsis, may feedback to dampen the response.
Structural, functional, and evolutionary differences between PD-L1 and PD-L2
Authors: Philips Elliot A. , Techova Anna S. , Mor Adam , Kong Xiangpeng
Published: January 2023

The PD-1/PD-L1/PD-L2 axis is a critical immune checkpoint that tips immune responses towards tolerance. This axis has been heavily targeted in cancer immunotherapy with monoclonal antibodies, which block receptor-ligand interactions. PD-L1 is constitutively expressed at low levels and is induced on nearly all tissues upon IFN-gamma signaling. In contrast, PD-L2 expression is restricted mainly to antigen presenting cells (APC)s, such as dendritic cells and macrophages. PD-L2 has a 4-fold stronger affinity for PD-1 than does PD-L1. It has been proposed that W110 of PD-L2 accounts for this affinity difference; the corresponding PD-L1 residue is A121. To test this hypothesis, we produced, in a mammalian expression system, a set of PD-L1 and PD-L2 proteins with the W and A swapped, and studied their binding to PD-1 using surface plasmon resonance. Surprisingly, rather than decreasing affinity as expected, a W110A substitution improved affinity by decreasing the off-rate. We propose a novel structural mechanism for PD-L2’s affinity advantage, one that interestingly emerged upon the evolution of placental mammals. We examined the functional effect that these structural alterations have on the PD-Ligands ability to inhibit T cell activation and found a correlation. Additionally, we discovered that PD-Ligands homo- and hetero-dimerize in a manner similar to other B7-family members, with PD-L2 displaying the strongest homo-dimerization. Collectively, these data support our hypothesis that PD-L2 expression on APCs provides an inhibitory advantage, one that may heighten the tolerogenic hurdle that an immune response must overcome during the priming phase.
Leptin-stress response axis promotes allergic airway inflammation
Authors: Yang Xuexian O. , Zheng Handong , Zhang Xing , Wu Dandan , Luo Yan , Yang Xin , Chock Cameron , Liu Meilian
Published: January 2023

Allergic asthma and obesity are both leading health problems in the world. Recent Meta-analysis studies implicated a positive relationship between serum leptin, which is elevated in obese individuals, and the risk of asthma. However, it is not well understood how obesity-associated elevation of leptin increases the risk of asthma. In the current study, we have found that leptin induces the stress response factor XBP1s in pro-allergic TH2 cells, which is required for leptin-mediated pro-allergic TH2 cell survival and cytokine production. In vivo, mice fed with high fat diet had increased serum leptin as observed in human obese population and exacerbated asthmatic symptoms, associated with increased stress responses in CD4+ T cells. Our results reveal a previously unappreciated insight that obesity-associated hyperleptinemia contributes to enhanced pro-allergic lymphocyte responses through targeting the stress response pathway, leading to exacerbation of allergic asthma.
Immunization elicits antigen-specific antibody sequestration in sensory neurons
Authors: Chavan Sangeeta S. , Gunasekaran Manojkumar , Chatterjee Prodyot K. , Shih Andrew , Kumar Gopal , Lee Annette , Graf John , Meyer Dan , Marino Michael , Puleo Christopher , Ashe Jeffrey , Metz Christine N. , Tracey Kevin J.
Published: January 2023

The immune and nervous systems coordinate physiological responses to infection and injury. Immunological memory to pathogens is retained in lymphocytes, but the role of neurons in this process is unknown. Here, we report the surprising discovery that peripheral sensory neurons of dorsal root ganglia (DRG) of immunized mice sequester antigen-specific antibodies. A significant increase in the number of total IgG releasing neurons was observed in DRGs isolated from immunized mice as compared to controls (p<0.001). Around 20% of the neurons in DRGs are positive for antibodies. To determine whether sensory neurons synthesize antibodies, DRG neurons from mice immunized with KLH were analyzed by RNA-seq and qPCR. DRG sensory neurons lack enzymes (i.e., RAG1, RAG2, AID, or UNG) required for generating antibody diversity. Transgenic mice that express a reporter fluorescent protein under the control of IgG1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Neural sequestration of antibodies is observed in mice rendered deficient in neuronal Rag2, but not observed in sensory neurons isolated from mice that lack mature B cells (e.g., Rag1 knock out (KO) or μMT mice). Adoptive transfer of Rag1-deficient bone marrow into wild-type mice or wild-type bone marrow into Rag1 KO mice revealed that antibody sequestration is observed in sensory neurons of chimeric mice with wild-type bone marrow but not with Rag1-deficient bone marrow. Our studies demonstrate that DRGs do not synthesize antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. These studies reveal that antigen-specific antibodies and sensory neurons may collaborate in bidirectional communication.
A Non-Canonical Role for Interferon Regulatory Factor 3 Downstream of the Interferon Gamma Receptor
Authors: Guinn Zachary P. , Petro Thomas M.
Published: January 2023

IFN-γ promotes the expression of anti-viral and anti-tumoral genes which act intrinsically to the cell (e.g. ISG54, ISG49), as well as genes which express secreted factors (e.g. IP10, IL-15). The canonical pathway of the IFN-γ receptor (IFNGR) revolves around the phosphorylation of the transcription factor, STAT1, promoting its dimerization and localization to the nucleus where it induces the expression of target genes, like Interferon Regulatory Factor 1 (IRF1). Our lab has shown impaired IFNGR signaling in cells which do not express IRF3. IRF3 is a transcription factor canonically activated by Pathogen Associated Molecular Patterns (PAMPs) through Pattern Recognition Receptors (PRRs) like Toll-Like Receptor 3 (TLR3). TLR3 recognizes dsRNA and analogs like Polyinosinic-polycytidylic acid (Poly I:C). WT and IRF3KO RAW 264.7 cell lines expressing secreted luciferase (Lucia) under control of an ISG54 promoter were stimulated with IFN-γ, Poly I:C, or both. IRF3KO RAW-Lucia cells had significantly reduced ISG54 promoter activity in response to all treatments compared with WT RAW-Lucia. This was confirmed via western blot and qPCR analysis. Using qPCR, expression of ISG49 and IL-15 was also IRF3 dependent in response to all treatments. However, expression of IP10 was only IRF3 dependent in response to Poly I:C and not IFN-γ. Thioglycollate elicited peritoneal macrophages (PECs) generated from WT and IRF3KO mice also showed an IRF3 dependency for the expression of ISG54 in response to IFN-γ. These PECs did not show altered STAT1 phosphorylation or IRF1 expression. These data imply that IRF3 contributes to the non-canonical pathway of IFNGR signaling.
MARVELD1 promotes survival during septic shock in mice
Authors: Shi Ming , ZHANG XIAOJUN , FU KAI , CHEN XI , ZHANG SHUAI , TANG YU , MA ZHENGXIONG , WU QIONG
Published: January 2023

MARVELD1 is integral to the inflammatory response occurring during septic shock, although its precise function has yet to be determined. Here we show that compared with wildtype mice, listeria monocytogenes (LM)-induced septic shock in MARVELD1 knockout mice resulted in a heightened pro-inflammatory response and increased mortality. This observation was associated with impaired bacterial clearance related to marked inhibition of the macrophage phagocytic acitivity in MARVELD1 knockout mice. Consistently, the MARVELD1 knockout mice were more sensitive to a lethal endotoxin or LM challenge, while wildtype mice in the bacterial peritonitis model produced a significant survival benefit. These data highlight the crucial role of the MARVELD1 pathway in inducing an adequate macrophage response to polymicrobial sepsis, and both the therapeutic promise and potential risks of its modulation.
Inhibition of IFN-I signaling redirects STAT1 through the IL27R to enhance the generation of CXCR5+ follicular cytotoxic T cells
Authors: Huang Zhe , Zak Jaroslov , Pratumchai Isaraphorn , Teijaro John R.
Published: January 2023

Checkpoint blockade treatment has shown great potential in both chronic viral infection and cancer patients, however the efficacy relies on the number of responsive CD8 T cells. Recently a population of CXCR5+ follicular CD8 T cells (TFC) has been identified in chronic LCMV infection and cancer models as the cells provide the proliferation burst and effector function following anti-PD-1/PD-L1 therapy. Understanding the cellular and molecular mechanisms regulate TFC differentiation and expansion will be crucial for improving the efficacy of immunotherapy. Here, we demonstrate that blockade of IFN-I signaling promotes a cell-intrinsic and sustained generation of TFC following persistent virus infection. Paradoxically, we observed a subset of ISG in TFC were induced by the cytokine IL-27 via STAT1 transcriptional program in the absence of IFN-I signaling. Moreover, blockade of IFN-I signaling either with antibody or pharmacologically through JAK inhibition, promoted the expansion of TFC during viral infection through an IL-27 and STAT1-dependent mechanism. Our results uncover a contrasting role of IL-27 and IFN type I in regulating the expansion of TFC despite their highly overlapping transcriptional signatures. Moreover, we demonstrate that pharmacological inhibition of JAK1/2 signaling induces optimal TFC generation without compromise effector CD8 T cell proliferation and function.
Aryl-hydrocarbon receptor-driven responses of innate lymphocytes
Authors: Stojanovic Ana , Correia Margareta P. , Klein Klara , Angel Peter , Platten Michael , Müller-Decker Karin , Cerwenka Adelheid
Published: January 2023

Innate Lymphoid Cells (ILCs) play significant roles during immune responses to infection at barrier sites and in the control of tissue damage and repair. In addition, ILCs have been involved in several pathologies, including exacerbated inflammation and carcinogenesis. However, understanding the contribution of distinct ILC subsets and modules of their regulation in both homeostasis and disease, is still incomplete. The Aryl-hydrocarbon Receptor (AhR) is a ligand-induced transcription factor that binds various exo- and endogenous polycyclic hydrocarbons and induces transcription of numerous target genes involved in development, cell differentiation and immune response. Here, we show that subsets of NKp46-expressing ILCs, including natural killer (NK) cells and helper ILC1, express AhR and respond to stimulation with AhR ligands. Exposure of NK cells to the tryptophan degradation product kynurenine, an endogenous AhR ligand, induced changes in global gene expression and primed NK cells for enhanced effector responses, including cytokine secretion and migration. In the context of diet-induced chronic liver damage, NK cells accumulated in the liver in an AhR-dependent manner. Conditional AhR deletion abolished NK cell accumulation, which correlated with reduced liver damage. In contrast to NK cells, liver resident helper ILC1 required AhR for the development and/or maintenance. In conclusion, the AhR is expressed by ILC1 subsets and differentially affects their development and effector responses. This might impact ILC1-driven responses in the context of chronic liver damage and could be of significance for liver tissue regeneration.
Global phosphoproteomic analysis of PD-1 signaling reveals T cell subset specific PD-1 functions
Authors: Tocheva Anna S. , Peled Michael , Nayak Shruti , Philips Elliot A. , Ueberheide Beatrix , Mor Adam
Published: January 2023

PD-1 is a cell surface receptor with immunoregulatory properties expressed in activated T cells. PD-1 binds to either PD-L1 or PD-L2 and mediates downstream tyrosine dephosphorylation of key proteins critical for TCR signaling. This prevents excessive inflammation as well as T cell mediated anti-tumor immunity. Anti-PD-1 therapy is effective in ~30% of cancer patients, of which up to 25% develop off-target immune inflammation. Little is known about downstream signaling triggered by PD-1 and further analysis will provide better rationales for safer and more effective PD-1 targeting therapies. We performed tandem mass tag spectrometry and examined protein phosphorylation in Jurkat T cells following PD-1 ligation by PD-L2. Computational analysis revealed the PD-1/PD-L2 phosphoproteomic landscape. Our results confirm previous reports that PD-1 ligation dephosphorylates key proteins in the TCR signaling cascade. In addition, compared to unstimulated cells and to cells stimulated via the TCR alone, αCD3 stimulation in the presence of PD-1 ligation led to significant dephosphorylation of proteins involved in cytoskeletal organization and cellular adhesion. Surprisingly, we observed increased S/T phosphorylation of proteins associated with cell cycle regulation, chromosomal organization and negative regulation of gene expression triggered by PD-1 ligation. Further analysis in primary human cells revealed that these PD-1 triggered pathways were T cell subset specific, which is key for developing T cell subset specific targeted therapies. Our study provides a comprehensive system wide view of the signaling cascade downstream of PD-1 and may serve as a springboard for future therapeutic approaches targeting the PD-1 pathway.
Notch signaling is protective in splenic T cells against apoptosis during endotoxemia via TLR4/Myd88/TRIF/iNOS/NO/TACE pathway.
Authors: Yang Chenxuan , Deng Meihong , Scott Melanie , Billiar Timothy R.
Published: January 2023

Introduction

Notch signaling regulates cell communication and fate decisions, though recently implicated in inflammatory responses, its regulation and roles in sepsis are unknown. We aim to study the biology of Notch signaling in endotoxemia.

Methods

WT (C57BL/6), Myd88−/− , TRIF−/−, TLR4−/−, iNOS−/−mice were injected saline or 5mg/kg LPS i.p, spleen and serum were harvested after 0, 4, 8, 12, 24h. The activation of Notch signaling was assessed as notch intracellular domain (NICD), and apoptosis was measured as cleaved-caspase 3 level by western blot.

Results

The NICD level in spleen peaked at 8h, decreasing to baseline level at 24 h after LPS injection. Cleaved-caspase 3 level in spleen was inversely correlated to the NICD level. Inhibition of Notch activation using DAPT (5 mg/kg) resulted in an increase of cleaved-caspase-3 at 8h after LPS stimulation, suggesting a critical role of Notch signaling for splenocyte survival after LPS stimulation. The sheddase, TNFα-converting enzyme (TACE/ADAM17) participates in activation of Notch and we have previously shown its activation via TLR4/iNOS/NO pathway in hepatocytes, thus we tested whether the pathway is conserved in spleen. LPS-induced Notch activation was significantly lower in TRIF−/−, Myd88−/− , TLR4−/− and iNOS−/− mice. In vitro treatment of SNAP (200 uM) and cGMP analog 8-pCPT-cGMP(400 uM) increased NICD level in primary splenocytes. Treatment with 1400W, an iNOS inhibitor or TAPI-II (800 nM), a TACE inhibitor, reduced LPS-induced Notch activation in splenocytes while increasing cleaved-caspase3.

Conclusion

Our data suggests that Notch signaling is activated during endotoxemia under the regulation of iNOS/NO/TACE and plays a critical role in regulating splenocytes survival.
The incorporation of active learner centered strategies to support improved memory recall and classroom engagement within postgraduate education blended learning education frameworks
Authors: Sika-Paotonu Dianne
Published: January 2023

Immunology education is a vital component for the clinical health sciences context. The inclusion of undergraduate Immunology teaching content within nursing, midwifery and health related courses however remains inconsistent. Blended learning environments provide the opportunity for learner centered classroom activities to support more traditional learning methods. To promote effective teaching and learning of Immunological related content at postgraduate level for classes with students with mixed experiences of Immunology education, integration of active learning and teaching strategies into postgraduate clinical sciences education are needed. The purpose of this work was to explore and assess the impact of Immunological based active memory recall exercises within a blended learning environment for postgraduate clinical health sciences students. Face-to-face Immunology teaching sessions for the Postgraduate Pathophysiology course were delivered with the incorporation of short memory recall sessions throughout in-class time where students recalled their understanding of recent learning content. Students demonstrated improved understanding, memory recall of Immunological concepts in addition to improved in-class engagement and ability to answer verbal in-class questions. In addition to enjoying the session time in class, improved confidence regarding Immunological content covered in class was also noted. Enhanced student knowledge and understanding of Immunology was achieved using integration of active learning and teaching strategies such as Immunology based memory recall exercises within blended learning postgraduate clinical sciences education frameworks.
The antagonist/agonist exam question: thinking like a scientist.
Authors: Parkin Kirstin
Published: January 2023

The goal of my undergraduate immunology course is to teach students how to think like a scientist, specifically how to think like an immunologist. The course has 150 students enrolled each year and I use a variety of team-based, active learning strategies in the classroom and four exams with a similar format that reflect on the class activities. Each exam consists of 4 short answer questions. One question involves students designing their own graphs to represent data from a primary research article covered during the class, and then using labeled drawings to demonstrate how the data is connected to cellular/molecular interactions in an organism. The second question requires students to propose methods for identifying two test tubes containing different contents, such as IL-10 and IL-12, when the test tubes are unlabeled. The third question assesses the ability of students to use labeled drawings to demonstrate cellular interactions, such as the receptor/ligand interactions that would likely lead to a successful vs. unsuccessful pregnancy. Finally, the students are asked to create treatments for conditions such as allergies, transplant rejection, specific autoimmune diseases, and immunodeficiencies. One of the treatments must involve an agonist and the other must involve an antagonist. The student use graphs to demonstrate expected results when the treatments are effective or ineffective. When students were polled on which of the four questions addressed the goal of teaching them how to think like an immunologist, over ninety percent of the students chose the antagonist/agonist question. The use of the agonist/antagonist question promotes deeper understanding of the activating and inhibitory signals that control immune responses.
Immunology Education for English Second Language learners within a Postgraduate Nursing Science program in New Zealand
Authors: Sika-Paotonu Dianne , Tait Carolyn
Published: January 2023

Immunology education is fundamental to support in-depth understanding of many pathological conditions. It is imperative to ensure all students are supported in their learning efforts and that curriculum and teaching content is relevant and appropriately delivered for all students, and in particular English Second Language (ESL) learners. Postgraduate Clinical Health Science ESL learners who have undertaken undergraduate Nursing studies in alternative settings with limited Immunology content may require support at postgraduate level. The purpose of this work was to ensure incorporation of Immunological components within a postgraduate Clinical Health Sciences course was appropriate for all, including ESL learners. In-class Immunology teaching sessions incorporated within a postgraduate Pathophysiology course were delivered to ensure cultural appropriateness for all students, including ESL learners. Active learning approaches employing the use of scientific on-line animations, interactive websites, Youtube scientific content and selected readings were adopted to ensure content delivery was culturally appropriate, stimulating, supported student engagement and participation for in-class learning and teaching activities. Active student engagement and in-class participation was observed with positive student satisfaction scores in response to the Immunological course content from formal student evaluation by all students recorded. Favorable assessment outcomes for Immunological components were noted for all students including ESL learners. These findings support the need to ensure Immunology education for postgraduate Clinical Health Sciences students is appropriate for all, including ESL learners.
Antibacterial resistance of severely burned mice treated with an RORα selective inverse agonist
Authors: Ito Ichiaki , Kobayashi Makiko , Finnerty Celeste C. , Herndon David N. , Suzuki Fujio
Published: January 2023

In our previous studies, an antibacterial resistance of severely burned mice to enterococcal translocation has been improved by treatment with RORα selective agonist SR3335 (an inhibitor of ILC2 activation). Therefore, the effect of SR3335 against infections with P. aeruginosa (PA) and MRSA was studied in severely burned mice. Severely burned mice (30% TBSA burn) infected with PA (103 CFU/mouse, i.d.) or MRSA (106 CFU/mouse, i.v.) 3 days post burn injury were treated i.p. with 100 μg/mouse of SR3335 simultaneously, 1 and 2 days after the infection. The antibacterial effect of SR3335 was evaluated by bacterial growth in organs of these mice 3-5 days post-infection. In some experiments, lamina propria mononuclear cells (LPMC) were isolated from burned mice treated with or without SR3335, and analyzed for lin−CD127+ICOS+Sca-1+ cells (ILC2), F4/80+CD11b+IL-12+CD38+ cells (M1Mϕ), F4/80+CD11b+CD206+ cells (M2Mϕ), and Gr-1+CD11b+ cells (MDSC) by flow cytometry. In the results, PA and MRSA vigorously grew in various organs of burned mice. However, both of the pathogens did not grow in organs of the same mice treated with SR3335. The number of ILC2 increased greatly in the LPMC of burned mice, while this increase was not shown in these mice treated with SR3335. The numbers of M2Mϕ and MDSC increased in the LPMC of burned mice, while the numbers of these cells were not increased in the same mice treated with the compound. M1Mϕ were induced by CpG DNA in cultures of LPMC isolated from burned mice treated with SR3335. These results suggest that SR3335 improves the antibacterial resistance of severely burned mice against PA and MRSA through the modification of burn-associated appearance of ILC2, M2Mϕ, and MDSC.