bluuebunny/crossref_metadata_2025 huggingface dataset:
MicroRNA-146a limits tumorigenic IL-17-mediated inflammation in colorectal cancer
Authors: Garo Lucien Peter , Ajay Amrendra K , Fujiwara Mai , Gabriely Galina , Raheja Radhika , Gopal Murugaiyan
Published: January 2023

Interleukin-17 (IL-17) is a major inflammatory cytokine implicated in colorectal cancer (CRC) development. However, the mechanisms that control tumorigenic IL-17 signaling remain unclear. Recently, expression changes and polymorphisms in the small non-coding RNA, microRNA-146a (miR-146a), have been associated with clinical outcomes in inflammatory bowel disease and CRC patients. Here, we identified a novel role for miR-146a as a major negative regulator of colonic inflammation and tumorigenesis via modulation of IL-17 responses. MiR-146a-deficient mice are highly susceptible to both colitis-associated and sporadic CRC, and present with enhanced tumorigenic IL-17 signaling. Within myeloid cells, miR-146a targets RIPK2, an intermediate in NOD2 signaling, to limit myeloid cell-derived IL-17-inducing cytokines and restrict colonic IL-17 levels. Accordingly, myeloid cell-specific deletion of miR-146a leads to CRC susceptibility. Moreover, within intestinal epithelial cells (IECs), miR-146a targets TRAF6, an intermediate in IL-17R signaling, to restrict IEC responsiveness to IL-17. MiR-146a within IECs further suppresses CRC by targeting PTGES2, an enzyme for PGE2 synthesis. IEC-specific deletion of miR-146a therefore confers marked CRC susceptibility. Importantly, preclinical administration of miR-146a mimic can ameliorate colonic inflammation and CRC. In conclusion, miR-146a prevents CRC by two interlinked mechanisms: 1) by limiting myeloid cell-mediated inflammatory IL-17 production; and 2) by inhibiting tumorigenic IL-17R signaling in IECs. Overexpression of miR-146a may be a promising therapeutic approach for CRC to limit multiple pathways converging on tumorigenic IL-17 signaling.
B cells produce anti-inflammatory cytokine IL-27 in the gut upon induction by cyclic dinucleotides and to prevent murine colitis
Authors: Wu Shuai , Yan Hui , Rivera Carlos Eduardo , Wang Jingwei , Fernandez Maria , Li Xiaodong , Wang Xiaoyan , Xu Zhenming
Published: January 2023

In addition to differentiating into plasma cells that secrete microbiota-shaping protective IgA antibodies, B cells may function as regulatory cells that are induced to produce cytokines to maintain gut integrity. In mouse gut-associated lymphoid tissues and mesenteric lymph nodes, B cells were the primary source of IL-27 in homeostasis and upon induction by dextran sulfate sodium (DSS)-elicited intestinal injury. Production of pleiotropic cytokine IL-27 (EBI3/p28) by B cells was dependent on their expression of STING, consistent with the ability of cGAMP, the cyclic dinucleotides (CDNs) product of cGAS upon sensing DNA, to prime B cells for IL-27 induction by CD154. Furthermore, B cell-specific deficiency in IL-27 (but not IL-35) or STING in DSS-treated mice resulted in specific impairment in generating plasma cells and T-bet+NCR+ Group 3 innate lymphoid cells (ILC3s), reduced IgA secretion into the gut lumen and expression of anti-inflammatory IL-22 (and concomitant increase in pro-inflammatory IL-17, as produced by T-bet−NCR− ILC3s) and severe colitis-like symptoms. These, together with the ability of IL-27-producing B cells generated in vitro by cGAMP priming and CD154 stimulation to prevent lethality caused by sustained DSS treatment, show that B cells in the gut respond to immunoactive CDNs to induce IL-27 for the maintenance of intestinal homeostasis.
Microbial hydrogen economy alleviates colitis by reprogramming colonocyte metabolism and reinforcing intestinal epithelial barrier
Authors: Ge Li , Qi Jie , Sun Xueqiang , Liu Shuman , Li Pengfei , Chen Hao , Shao Bo , Wang Shiyang , Ruan Zhenzhen , Song Wengang
Published: January 2023

Several studies have found exogenous H2 treatment can alleviate inflammatory damage in inflammatory bowel disease (IBD) animal models, but the mechanisms behind it are less clearly understood. The present study aimed to investigate whether hydrogen-rich saline (HS) attenuates IBD in mice model and the underlying mechanisms. The results showed that HS administration significantly inhibit weight loss and reduce inflammatory damage in dextran sulfate sodium (DSS)-induced acute ulcerative colitis (UC) mice model. We observed that H2 regulates the composition of microbiota by up-regulating the abundance of intestinal specific short chain fatty acids (SCFAs)-producing bacteria. Increased butyrate-producing microbes activated the intracellular butyrate sensor peroxisome proliferator–activated receptor γ (PPAR-γ) signaling pathway, meanwhile decreased the epithelial expression of Nos2, the gene encoding inducible nitric oxide synthase, and thus promoted the recovery of colonic anaerobic environment. Our results also indicated that HS administration reduce intestinal epithelial barrier permeability by decreasing the dextran concentrations in serum, inhibit dysbiotic Enterobacteriaceae expansion, increasing mucus secretion in the colonic lumen, and promoting the expression of intestinal interepithelial tight junction protein. Taken together, we identified the mechanism by which exogenous H2-improved “microbial hydrogen economy” regulates metabolic reprogramming of colonocyte through microbiota-activated PPAR-γ signaling pathway to provide colonic anaerobic environment, and reinforces intestinal epithelial barrier function, thereby promoting the recovery of intestinal homeostasis.
Efferocytosis mediated by TAM receptors maintains lung homeostasis and controls inflammation in a mouse model of silicosis
Authors: Pinto Kamila Guimaraes , Ferreira Antonia Castro , Leandro Monique , Lopes Marcela F , Vazquez Estefania , He JianPing , Kelsall Brian L , Filardy Alessandra
Published: January 2023

Alveolar macrophages (AMs) are key cells for the establishment of pulmonary homeostasis. Efferocytosis is one of the main regulatory mechanisms for maintaining tolerance and homeostasis. The TAM receptor family (Tyro3, Axl and MerTk) mediates efferocytosis and inhibits proinflammatory pathways through Gas6 or Protein S binding to phosphatidylserine on apoptotic cells. Here we investigated how lung macrophages are regulated by TAM receptors in homeostasis and during silicosis. We found that LPS-stimulated AMs have an impaired ability to secrete IL-1b, IL-6, IFN-b, and MCP-1, but produce high levels of TNF-a and lower levels of IL-10, compared to bone marrow derived macrophages (BMDM). During homeostasis, AMs from wild type (WT) mice showed high expression of Axl, MerTk, and Gas6 by RT-PCR. Compared to WT mice, Axl−/− and MerTk−/− mice had more airway cells, less TGF-b and IL-10, and higher levels of IL-17 and KC within BAL. In addition, both KO mice had a higher frequency and number of AMs in the BAL, and secreted high levels of MCP-1, IFN-b, GM-CSF, and IL-10 following LPS stimulation compared to WT mice. Fifteen days after intra-tracheal silica instillation (SiO2; 20 mg), Axl−/− and MerTk−/− mice lost more body weight, and had increased lung weight, and percentage and number of neutrophils in the BAL compared to WT mice. Furthermore, both KO mice had a decreased percentage of AMs, and higher levels of KC, TNF-α and TGF-β but lower levels of IL-10 in the BAL compared to WT mice. Finally, Axl−/− mice had higher levels of IL-1β and IL-6 in the BAL than MerTk−/− mice. Our data suggest that efferocytosis mediated by Axl and MerTk receptors plays an important role in maintaining homeostasis and controlling inflammation in the pulmonary mucosae.
Do inflammasomes play a role in controlling cell damage/injury (ARDS) in order to initiate the cascade of healing and tissue repair?
Authors: Lau Jenny May-Sim , McKay Emma , Curran Joseph , Bertholon Tara , Krasnodembskaya Anna , Ingram Rebecca , Fitzgerald Denise , O’Kane Cecilia , Dombrowski Yvonne
Published: January 2023

Inflammasomes are cytosolic multiprotein complexes that assemble in response to various stimuli. Activated inflammasomes process pro-IL-1β and pro-IL-18 into bioactive forms. inflammasome-derived IL-1β initiates epithelial cell and fibroblast proliferation. Thus, inflammasomes might also be decisive key drivers through activating and recruiting cells required for efficient tissue repair. However, their exact function in lung tissue damage and repair are unclear. C57BL/6, NLRP3−/− and Caspase1/11−/− mice were treated with 40μg LPS by intratracheal instillation to induce lung injury. Lungs and BALF were collected for histological scoring, cytokine analysis and inflammasome marker expression by IHC, immunoblotting and ELISA. The Lung injury score of LPS treated mice was increased on day 1 and 3 but reverted to nearly normal on day 7. NLRP3 deficiency did not alter lung damage indicating that the NLRP3 inflammasome might not be an essential mediator of injury in this model. LPS induced lung epithelial type 2 cell damage was shown by decreased Pro-SPC expression, which was associated with increased expression of inflammasome markers (ASC, NLRC4, and NLRP3) and pro-IL-1β. Immune cells and more specifically CD68+ macrophages and Ly6G/C+ neutrophils were the predominant cell types expressing inflammasome markers. Caspase1/11−/− mice had reduced IL-1β levels in BALF compared to LPS-treated C57BL/6 mice indicating a potential role of inflammasomes in response to tissue damage. However, both NLRP3−/− and caspase1/11−/− mice had no significant change in CXCL1/KC levels in BALF compared to C57BL/6 mice on Day 3 and 7 of the acute lung injury model. Further investigations will reveal the impact of inflammasome activity on tissue repair.
Effects of E-Cigarette Vapor on the Pulmonary Immune System
Authors: Poindexter Morgan E , Laing Emilia , Singhrao Navid , Li Xiaohan , Pinkerton Kent E.
Published: January 2023

E-cigarettes are nicotine delivery devices that have rapidly gained popularity in recent years. It is not well understood how the use of these devices impact the pulmonary immune system and its ability to defend against respiratory viral infection. To this end, BALB/c mice were exposed to e-cigarette aerosols for 3 hours per day, 5 days per week for 2 weeks. Lung tissue and serum were collected following 1, 3, 5 and 10 days of exposure. Average serum nicotine and cotinine concentrations during the 10-day exposure were 133 ± 46 ng/mL and 712 ± 302 ng/mL, respectively, which is consistent with levels found in active tobacco smokers. Compared to filtered air controls, e-cigarette exposure significantly increased total cells and macrophages in bronchoalveolar lavage fluid on days 1 and 5, and significantly decreased neutrophils on day 1, suggesting that e-cigarette vapor may change the cellular infiltrate of the lungs. mRNA expression of IL-1β, IL-6, TNFα and IL-10 in right lung tissue was significantly decreased at all timepoints, suggesting possible dampening of the pulmonary immune response. To investigate how these cellular changes may effect the response to viral stimuli, human Type II epithelial cells were treated with e-cigarette conditioned media 24 hours prior to poly(I:C) stimulation. Compared to controls, e-cigarette treatment of type II epithelial cells resulted in significantly decreased expression of the critical interferon pathway genes IRF3, IFNα, and IL-1β following poly(I:C) stimulation. E-cigarette media alone was able to significantly decrease the expression of IRF3 in these cells, suggesting e-cigarette vapor may impair key genes necessary for the recognition of and sufficient response to respiratory viruses.
Anti-dsDNA specific antibody secreting cells are increased in both frequency and abundance in Chronic Rhinosinusitis with Nasal Polyps
Authors: Bai Junqin , Hulse Kathryn E. , Huang Julia , Schleimer Robert P. , Tan Bruce K.
Published: January 2023

Background

We have previously found that anti-dsDNA IgG autoantibodies are increased in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) patients. Recent studies find that B cells with the Epstein-Barr virus-induced protein 2(EBI2), is critical to the extrafollicular response. We have described elevated numbers of EBI2+ B cells in NP and they were more frequently antibody secreting cells (ASCs). In this study we evaluate whether dsDNA-specific ASCs are increased in NP and further compared the EBI2+ and EBI2− compartments.

Methods

To investigate this problem, flow cytometry and ELISpot assays were utilized to compare the frequency of total IgG and dsDNA specific IgG ASCs and cells were sorted into EBI2+ and EBI2− B cells from human NP and tonsils.

Results

Flow cytometry results (n=10 tonsil, 4 NP) found that although tonsils had significantly more B cells than NP, a significantly smaller proportion were CD27+CD38+ plasmablasts (PB). Further ELISpot analysis found NP B cells were more frequently IgG ASCs than tonsil (0.06% and 0.43% in tonsil (n=9) and NP (n=5) respectively, p<0.001). Anti-dsDNA specific ASCs were two-fold more in NP representing 0.95% of IgG ASCs compared with 0.4% in tonsil ASCs (p<0.05). In analysis of ASCs sorted from tonsils (n=3) and NP (n=2), we found anti-dsDNA IgG ASCs were more frequent among EBI2+ compared to EBI2− cells with 10- and 14-fold increases in dsDNA reactivity (p<0.01).

Conclusions

Although B-cells are significantly more abundant in tonsils, NP derived B-cells more frequently secrete total- and dsDNA-specific IgG. These differences appear to be driven by extrafollicular EBI2+ B-cells suggesting that EBI2+ B cells represent the major pool of autoreactive B-cells observed in CRSwNP and tonsils.
Airway mucociliary dysfunction enhances antigen-specific nasal IgA immune responses to cholera toxin-based nasal vaccine
Authors: Lan Huangwenxian , Suzuki Hidehiko , Nagatake Takahiro , Hosomi Koji , Ikegami Koji , Setou Mitsutoshi , Kunisawa Jun
Published: January 2023

Nasal mucosal tissues are equipped with physical barriers, mucus and cilia, on their surface. The mucus captures inhaled materials, and the cilia remove the captured materials from the epithelial layer by asymmetrical beating. Effect of nasal physical barriers on the vaccine efficacy remains to be investigated. Tubulin tyrosine ligase-like family member 1 (Ttll1) is an essential enzyme for appropriate movement of the cilia on respiratory epithelium, and its deficiency (Ttll1-KO) leads to the impaired asymmetrical beating of cilia and consequent mucus accumulation in the nasal cavity. Here, when mice were intranasally immunized with pneumococcal surface protein A (PspA) together with cholera toxin, Ttll1-KO mice showed higher levels of PspA-specific IgA in the nasal wash and increased numbers of PspA-specific IgA-producing plasma cells in the nasal passages when compared with Ttll1 hetero (He) mice. Mucus removal by N-acetylcysteine did not affect the enhanced immune responses in Ttll1-KO mice. We further found that retention time of PspA in the nasal cavity in Ttll1-KO mice was longer than that in Ttll1-He mice. Consistently, uptake of PspA by dendritic cells was higher in the nasopharynx-associated lymphoid tissue (NALT) of Ttll1-KO mice than that of Ttll1-He mice. These results indicate that the ciliary function of removing vaccine antigen from the NALT epithelial layer is a critical determinant of the efficacy of nasal vaccine.
Krüppel-Like-Factor 2, a new player in mucosal IgA homeostasis
Authors: Wittner Jens , Schulz Sebastian R , Steinmetz Tobit , Hutloff Andreas R , Cunningham Adam F , Jäck Hans-Martin , Schuh Wolfgang
Published: January 2023

Krüppel-Like-Factor 2 (KLF2) is a transcription factor that controls organ development, differentiation and trafficking of cells. In the immune system, KLF2 fosters the egress of T lymphocytes from the thymus via S1PR1 and promotes quiescent states of B lymphocytes as well as homing of antigen-specific IgG plasmablasts (PB) and plasma cells (PC) to the bone marrow (BM) via the α4β7 receptor.

To investigate the PC-specific role of KLF2, we analyzed CD138+/TACI+ PB/PC subpopulations and isotype changes in various organs such as spleen (SP), BM, gut associated lymphoid tissues (GALT) and blood of KLF2-deficient mice in comparison to their mb1cre+ KLF2wt/wt controls. Therefore, FACS and Elispot analyses showed a striking reduction of IgA+ PB/PC in SP, BM and blood of non-immunized mice. Elisa and multiplex data revealed a strong reduction in serum IgA as well as (s)IgA in the feces of KLF2-deficient mice. However, frequencies of IgA+ PB/PC were not changed in GALT but total PB/PC accumulated in mesenteric lymph nodes (mLN) and Peyer’s Patches. In addition, IgA secretion of these cells was not effected.

Based on these data, we conclude that the observed IgA-deficiency in KLF2-deficient mice can in part be explained by impaired egress of class switched PB/PC from their organ of generation to survival niches in the bone marrow and gut by controlling the expression of integrins.

To address the consequences of a dysregulated PB/PC migration during infection, we are analyzing a GALT-dependent immunization with recombinant Flagellin which is known to trigger a systemic IgG as well as an mucosal IgA response. Furthermore, we are identifying KLF2 target genes that control PC egress and trafficking by RNAseq of IgA+ PB/PC from the mLN of KLF2-deficient mice.
Effect of maternal obesity on neonatal immunity
Authors: Vozenilek Aimee E , Sakai Jiro , Akkoyunlu Mustafa
Published: January 2023

Introduction

Maternal obesity has been shown to enhance infection, autoimmunity, and allergic sensitization in murine offspring. These data suggest that maternal obesity may be altering the neonatal immune system, but this process has not yet been elucidated. In this study, we are investigating the differences between the immune systems of neonatal mice born to obese versus lean mothers. We are also investigating how maternal obesity influences neonatal immune responses to vaccines since most pediatric vaccines are introduced during the first year of life.

Methods

Flow cytometry is used to compare splenocyte populations from neonatal offspring of high-fat and control diet parents. Immune responses of neonates to tetanus toxoid conjugated pneumococcal type 14 polysaccharide vaccines (PPS14-TT) are assessed. RNAseq is performed to investigate differences in peritoneal macrophage inflammatory states in neonatal offspring of high-fat and control-diet parents.

Results

7-day old neonatal mice from high-fat diet parents have a higher percentage of T cells (CD3+) in the spleen compared to neonates from control-diet parents. The high-fat diet offspring also have an increased B cell (B220+) population. Interestingly, although IgG antibody responses to PPS14-TT vaccine was comparable in the neonates from the two groups, those born to obese mothers developed significantly higher levels of IgM antibodies.

Conclusions

Data obtained so far suggest that maternal obesity influences the development of the adaptive immune cell populations and alter the antibody responses to vaccines in neonatal offspring. More detailed analysis of neonatal immune responses to vaccines will be presented at the meeting.
Treg dysfunction in aging oral mucosa
Authors: Pandiyan Pushpa
Published: January 2023

Aging leads to an increased susceptibility to infections, a phenomenon called immunosenescence. An imbalance between proinflammatory and anti-inflammatory mechanisms is also observed during aging. However, mechanisms of mucosal tissue specific infections and inflammation, and the underlying immune cell alterations in these tissues are incompletely understood. Here our objective was to understand oral mucosal immune cells, especially regulatory T cells, a population of CD4+ T cells that are central to immunomodulation. We infected young (2–3 months) and aged (>18–24months) C57BL/6 mice with a sublingual inoculation of 2 × 107 Candida albicans (SC5314) blastospores under anesthesia. We reinfected the mice on day 7 and day 16 after primary infection to mimic recurrent/secondary infections, monitored their weight loss and tongue immunopathology. Control mice were sham infected with PBS. We isolated oral draining cervical lymph nodes (CLN) cells and mouse oral intraepithelial and lamina propria cells (MOIL), and determined the frequency, absolute cell numbers and functions of T and inflammatory CD4 T cells ex vivo before and after infection. We found that aged mice continuously lost weight during the course of the recurrent infections, whereas young mice regained their weight after every infection. Immunosenescent phenotype in aged mice was associated with heightened tongue immunopathology, compared to young mice. Increased oral inflammation phenotype was associated with Treg dysfunctions in local oral tissue. Taken together, our study begins to define T cell dysfunctions and inflammatory processes underlying decline of the immune responses in oral mucosa.
Oral administration of antigen mainly induces T helper lineage-negative CD200+ CTLA4+ anergic CD4+ T cells which tend to become regulatory T cells
Authors: Hong Sung-Wook , Jenkins Marc K
Published: January 2023

CD4+ T cells do not normally undergo productive immune responses to orally administered foreign antigens. It has been proposed that this oral tolerance phenomenon is explained by CD4+ T cells with T cell receptors (TCRs) specific for MHCII-bound peptides from ingested antigens becoming unresponsive (anergic) or differentiating into T regulatory (Treg) cells. Not much is known, however, about the phenotype and function of cells undergoing this process within the polyclonal CD4+ T cell repertoire. We addressed this issue by using I-Ab tetramers containing a foreign peptide called 2W to track 2W:I-Ab-specific CD4+ T cells after oral gavage of C57BL/6 mice with 2W peptide. These CD4+ T cells underwent weak clonal expansion when exposed orally to 2W peptide and generated a population consisting of 10% Foxp3+ Treg cells, 10% CXCR5+ follicular helper cells (Tfh), and ~3 % TBET+ Th1 or RORgt+ Th17 cells. The dominant subpopulation, however, did not express any of the known T helper cell lineage markers. Analysis of 80 surface proteins including CD73, FR4, CD200, PD-1, P2X7, and CTLA-4 revealed that these T helper lineage-negative (Thlin−) cells were more similar to anergic cells than to effector or Treg cells. In addition, adoptive transfer of sorted 2W:I-Ab-specific Thlin− cells followed by oral gavage of the peptide showed that these Foxp3− cells can become Foxp3+ Treg cells much more efficiently than naïve T cells. Collectively, our data demonstrate that the majority of CD4+ T cells exposed to oral antigen become Foxp3− anergic cells with a tendency to become Treg cells.
Distinct contributions of CRAMP produced by epithelial cells and macrophages to colon mucosal homeostasis
Authors: Chen Keqiang
Published: January 2023

The cathelicidin-related antimicrobial peptide CRAMP (LL-37 in human) plays an important role in protecting the colon from inflammation, carcinogenesis and dysbiosis as demonstrated in systemic CRAMP-deficient mice. Since understanding the cellular origin of CRAMP in the colon is critical for elucidating its mechanistic basic of action and potential as a therapeutic agent for diseases, we examined the contribution of macrophage- versus epithelial cell-, derived CRAMP in protecting colon by using mice with conditional CRAMP deficiency. Here we report that the colon of mice systemically deficient in CRAMP contained increased bacteria attaching to the mucosa, which was phenocopied by mice with CRAMP deficiency in macrophages, but not epithelial cells. In chemically induced acute colitis, bacteria invading epithelial cells were significantly increased in mice with myeloid CRAMP deficiency, in association with more severe mucosal damage and higher rate of mouse mortality. In addition, macrophages from the bone marrow of myeloid CRAMP deficient, but not wild type, mice failed to eliminate intracellular E. coli. Mechanistically, elimination of intracellular E. coli by macrophages was dependent on a normal autophagy pathway which was disrupted in CRAMP deficient macrophages. In contrast to macrophages in the colon, CRAMP from epithelial cells mainly promoted the development of goblet cells and mucus production, with negligible contribution to bacterial containment. These results demonstrate distinctive roles of CRAMP derived from macrophages and epithelial cells in maintaining the homeostasis of the colon.
Temporal Maternal Influence on the Developing Microbiota
Authors: Greenfield Kara Grace , Floyd Alex , Newberry Rodney D , Knoop Kathryn A
Published: January 2023

The microbiota present on every mucosal surface of the body is imperative for the development and maintenance of the immune system. Disruption of the microbiota from environmental factors can affect immune components in both the mucosal and the systemic immune compartments. Following birth in mammals including humans and mice, the microbiota rapidly develops and matures into a composition generally seen in adults when infants are weaned. Gut microbiota composition is directly affected by feeding type, breast-fed vs formula-feeding, in humans, and the microbiota associated with breastfeeding has been shown to promote intestinal health. As the composition of breastmilk changes throughout lactation, we hypothesize maternal provided factors within breastmilk support the development of the microbiota in a temporally sensitive manner. To address this question we asynchronously cross-fostered (ACF) litters born on day 1 to dams who had delivered 2 weeks earlier. Gut microbiota composition was assessed by 16S analysis of stool samples at the time of weaning, and while the microbiota of synchronous cross-fostered pups resembled the microbiota of their foster dam, the microbiota of ASF mice was different from both their foster dam and the healthy microbiota seen in weanling mice. ACF mice had a significant reduction in bacteroides and firmicute species, species that generally represent the majority of the bacteria within a healthy microbiota, and expansion in prevotella species, which include clinically important opportunistic pathogens, suggesting ACF mice contain a dysbiotic microbiota. Future work will explore and identify what temporally dependent components in breast milk support the development of a healthy microbiota.
Genetic regulation of immune homeostatic lung leukocyte populations
Authors: Hampton Brea K , Jensen Kara , Whitmore Alan C. , Morrison Clayton R. , Plante Kenneth S. , Leist Sarah R. , Gralinski Lisa E. , Menachery Vineet D. , Schäfer Alexander , de Villena Fernando Pardo-Manuel , Baric Ralph S. , Heise Mark T. , Ferris Martin T.
Published: January 2023

Immune homeostasis is the state where the immune system maintains stability in the absence of insult. Much of the analysis of immune homeostasis has focused on systemic immunity, but it is also likely to be important in an organ specific manner. There is evidence that homeostatic immunity can affect subsequent responses to infection or vaccination. Since the lungs are a major site of infection, we used the Collaborative Cross (CC) mouse genetic reference population to study the genetic regulation of the breadth of baseline immune cell populations in the lung and identify loci regulating these cells at the steady state. We found that all immune cell populations measured showed strong genetic (i.e. strain-specific) variation in cell type abundances. We identified 12 quantitative trait loci (QTL) associated with variation in 12 immune cell populations or the relationships between cell populations. Given the role of various immune cells in the lungs during respiratory virus pathogenesis, we asked whether any of the mapped QTL correlated with influenza A virus (IAV) or Severe acute respiratory syndrome associated coronavirus (SARS-CoV) disease following infection in the same strains of mice. Notably, a locus we mapped for baseline abundance of CD8+ T cells in the lungs was associated with peak weight loss following IAV infection. Additionally, a locus mapped for variation in Ly6C+ monocyte/macrophage abundance was associated with SARS-CoV titer at days 2 and 4 post-infection. These data suggest that abundance of lung leukocyte populations prior to infection could serve as predictors of immune responses to respiratory viruses.
Quantifying the durability, expansibility, and tissue-autonomous nature of the immune system uncovers a resident reservoir for circulating immunity
Authors: Wijeyesinghe Sathi , Beura Lalit K. , Pierson Mark J. , Stolley J. Michael , Rosato Pamela C. , Masopust David
Published: January 2023

Immune cells develop in specialized lymphoid organs, but the mature immune system is integrated throughout the body and regulates tissue homeostasis and defense. This study examines how immunity persists within adult murine tissues while addressing issues of tissue autonomy, resistance to perturbations, and numerical contribution to the cellularity of visceral organs. Using quantitative immunofluorescent microscopy, we report that the immune system is expansible in nonlymphoid tissues following microbial experience, and hematopoietic cells comprise up to 30% of cells in visceral organs of laboratory mice housed in non-SPF conditions. Most hematopoietic cells in nonlymphoid tissues were autonomously maintained for >30 days, without contribution from circulation or primary lymphoid organs. Focusing on antiviral T cell immunity, we demonstrate tissue-autonomous maintenance of resident memory T cells for >200 days. Resident T cell memory was largely durable following significant environmental perturbations and de novo immune responses. Once established, resident T cells did not require the T cell receptor for survival, longevity, or retention of a poised effector-like phenotype. Ultimately, T cell memory did decay in some organs, not others, and gradually increased in circulation. Surgical separation of parabiotic mice unexpectedly revealed a tissue-resident provenance for memory T cells in peripheral blood. We propose a model whereby circulating memory T cells do not replenish resident populations, but instead a tissue-resident reservoir supports long-term maintenance of the bloodborne pool. Collectively, these data demonstrate the durability and autonomous nature of the tissue-integrated immune system.
Verdinexor, a selective inhibitor of nuclear export, decreases plasma cell survival in human lupus
Authors: Nandedkar Neha D , Meednu Nida , Albrecht Jennifer , Rangel-Moreno Javier , Barnas Jennifer L , Widman Douglas G , Anolik Jennifer H
Published: January 2023

Systemic lupus erythematous (SLE) is a complex autoimmune disease affecting multiple organs. Anti-nuclear antibody (Ab) producing plasma cells (PCs) play a critical role in the disease pathogenesis and are an important target for developing therapies against SLE. Karyopharm Therapeutics (KPTI) is an oncology-focused pharmaceutical company dedicated to the discovery, development, and commercialization of novel first-in-class drugs for the treatment of cancer and other major diseases. KPTI’s lead compound, XPOVIO™ (selinexor), received accelerated approval from the FDA in combination with dexamethasone as a treatment for patients with heavily pretreated multiple myeloma. KPTI’s selective inhibitors of nuclear export (SINE, verdinexor) are effective in reducing nephritis in the NZBW/F1 mouse model, and dramatically reduced autoreactive PCs. To further define whether SINEs directly decrease PC survival and/or generation, we studied PCs in human lupus ex vivo. Peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) from healthy (n=3) and SLE donors (n=3) were treated with verdinexor and PC survival was determined by IgG ELISPOT and apoptosis assay. Verdinexor treatment significantly reduced the number of Ab secreting cells from healthy and SLE donor PBMCs as well as BMMCs (IC50 =0.1uM). Upon ex vivo verdinexor treatment (0.5uM), the levels of live blood plasmablasts and bone marrow CD19+ PCs were reduced by 30% with increased level of apoptotic cells. In contrast, ex vivo verdinexor treatment had no effect on naïve B cells and T cells from healthy and SLE PBMCs and BMMCs. These results support the hypothesis that SINEs have a direct effect on PC survival and represent a novel treatment approach for SLE.
Retinoic acid exerts disease stage-dependent and tissue-specific effects on pristane-induced lupus
Authors: Abdelhamid Leila , Cabana-Puig Xavier , Swartwout Brianna , Lee Jiyoung , Li Song , Sun Sha , Li Yaqi , Ross A. Catharine , Cecere Thomas E. , LeRoith Tanya , Wang Haifeng , Reilly Christopher M. , Luo Xin M.
Published: January 2023

We previously showed that all-trans-retinoic acid (tRA) exacerbated pre-existing autoimmunity in lupus; however, its effects before disease onset are unknown. Here, using a pristane-induced model, we show that tRA exerts tissue-specific effects when given at the initiation vs. continuation phase of lupus. Pre-pristane treatment with tRA aggravated glomerulonephritis through increasing renal expression of pro-fibrotic protein laminin β1, activating bone marrow CD11b- conventional dendritic cells, increasing the splenic CD4:CD8 ratio, and upregulating the interaction of ICAM-1 and LFA-1 that led to the infiltration of inflammatory cells to the spleen. Transcriptomic analysis revealed that prior to lupus induction, tRA significantly upregulated genes associated with cell differentiation, activation, and migration. Moreover, compared to pristane alone, tRA pre-treatment potentiated, whereas tRA post-treatment significantly suppressed, the renal expression of proinflammatory TNF-α, IL-1β, CCL2, and CCL3. While it may benefit the kidney, post-pristane treatment with tRA worsened the onset and severity of pristane-induced arthritis through promoting neutrophil and mononuclear cell infiltration into the joints. Together, these findings suggest that tRA supplementation regardless of the time of administration promotes chemokine-driven migration and tissue-specific infiltration of inflammatory cells, thereby exacerbating lupus-associated kidney or joint inflammation. Interestingly, both pre- and post-treatments with tRA modulated the gut microbiota in a similar fashion, suggesting a gut microbiota-independent mechanism by which tRA affects the initiation vs. continuation phase of lupus.
Hydroxychloroquine enhances efferocytosis and inhibits IL-6 and TNF-α productions through upregulating both Gas6/Axl and MFG-E8/TG2 Signaling pathways in Pristine-induced lupus mice
Authors: Tsay Gregory J , Hsieh Fei-Hung , Xue Ting-Yin , Peng Hsin-Yi , Tsao Yan-Chi , Yin Mei-Chin , Chen Jiunn-Horng , Huang Chung-Ming , Chen Der-Yuan , Lan Joung-Liang
Published: January 2023

Objectives

Impaired clearance of apoptotic cells (efferocytosis) plays an important role in the pathogenesis of autoimmune diseases, especially systemic lupus erythematosus (SLE). Hydroxychloroquine (HCQ) has been widely used to treat autoimmune diseases. We aimed to investigate the underlying mechanism of efferocytosis in the action of HCQ.

Methods

Eighteen 6-week-old female BALB/c mice were treated Intraperitoneally with pristine in Pristine-induced lupus mice (PIL). Efferocytosis was performed using mouse cell lines EL4 as apoptotic cells and co-cultured with RAW 264.7 and peritoneal macrophages of PIL to investigate the effect of HCQ on efferocytosis which was analyzed with fluorescent microscopy and flow cytometry. Real time PCR was performed to investigate molecular mRNA expressions of signalling pathways. Protein level was measured by ELISA.

Results

HCQ could enhance efferocytosis with dose-dependent manner in both RAW264.7 cell lines and peritoneal macrophages of PIL with increased expression of GAS6 and MFG-E8 signallings. Both Gas6/Axl and MFG-E8/TG2 Signalling pathways play important roles in HCQ-enhanced efferocytosis. In HCQ-treated mice of PIL, HCQ reduced of IL-6 (p<0.0036) and TNF-α (p<0.06) protein levels in their ascites.

Conclusions

Our study shows that HCQ can enhance efferocytosis through both Gas6/Axl and MFG-E8/TG2 Signalling pathways and suppress the production of IL-6 and TNF-α. Our findings provide novel insights into understanding the mechanisms of HCQ, which could have the long-term beneficial effects on the therapy of SLE.
Amelioration of skin and kidney disease in a spontaneous murine lupus model via CD6 modulation
Authors: Chalmers Samantha A. , Garcia Sayra J , Ramachandran Rajalakshmy Ayilam , Mohan Chandra , Herlitz Leal , Ampudia Jeanette , Ng Cherie , Connelly Stephen , Putterman Chaim
Published: January 2023

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease that can affect multiple organ systems, including the kidneys, skin, and brain. T cells are an important mediator in this end organ damage. CD6 is a co-stimulatory receptor, predominantly expressed on T cells, which binds with activated leukocyte cell adhesion molecule (ALCAM), a ligand expressed on antigen presentation cells and various epithelial and endothelial tissues. This signaling pathway is vital for T cell activation, proliferation, differentiation and trafficking. We found increased expression of both CD6 and ALCAM in the kidneys of MRL/lpr mice (a spontaneous model of SLE) versus healthy control B6 mice. In a separate experiment, female MRL/lpr mice were aged to 9–10 weeks of age, at which point we began treating with either anti-CD6 antibody (60 ug/dose, intraperitoneally twice per week), isotype control (60 ug/dose, twice per week), or cyclophosphamide (25 mg/kg, once per week). We also included a no treatment group and a group of MRL/MpJ mice, a congenic healthy control strain. Mice treated with anti-CD6 show lower levels of proteinuria and BUN (p<0.05), improved survival rates, and decreased renal pathology compared to isotype control mice. Flow cytometry revealed decreased numbers of activated and effector T cells within the kidneys of anti-CD6 treated mice compared to isotype control mice. While there was no difference in anti-DNA levels, anti-CD6 treatment significant improved the spontaneous skin lesions associated with disease progression. Overall, these results indicate that targeting CD6-ALCAM interactions may have promising therapeutic potential within the context of different end organ pathologies within lupus.
Tumor necrosis factor like weak inducer of apoptosis (TWEAK) Promotes Inflammatory Activity in Keratinocytes with IL-17 and TNF to Drive Psoriasis
Authors: Gupta Rinkesh Kumar , Gracias Donald Tom , Burkly Linda C , Croft Michael
Published: January 2023

Psoriasis is an autoimmune skin disease caused by hyper-proliferation of keratinocytes driven by distinct inflammatory cells making cytokines such as IL-17 and TNF. Our previous studies with knockout animals revealed that the TNF-related cytokine TWEAK (TNFSF12) was also a critical contributor to skin inflammation and could be a potential therapeutic target in psoriasis. As Fn14, the receptor for TWEAK, is expressed by keratinocytes, we examined the inflammatory effects of TWEAK alone and with IL-17A and TNF in modulating psoriatic genes in human keratinocytes using RNA-seq. We found that TWEAK upregulated the expression of multiple chemokines and cytokines, such as IL-36G, IL-23A, IL-19, CCL5, CCL20, and other inflammation-associated genes, that have previously been found highly expressed in the skin of patients with psoriasis. TWEAK’s action was partially overlapping with IL-17 and TNF, but interestingly, in combination with IL-17 or TNF, TWEAK had strong synergistic effects in enhancing the expression of a number of these inflammatory genes. We then tested the impact of TWEAK neutralization on already existing skin inflammation in an imiquimod-induced psoriasis model. Mice treated therapeutically with anti-TWEAK showed significantly decreased numbers of immune cell infiltrates in the skin, with fewer γδ T cells, neutrophils and macrophages. These mice also exhibited a marked reduction in epidermal thickening, similar to mice treated with anti-IL-17 alone. Furthermore, co-neutralization of TWEAK and IL-17 demonstrated a greater effect in terms of reducing clinical symptoms. These data suggest that blocking TWEAK could be considered as a potential therapeutic avenue in humans to overcome the pathophysiology of psoriasis.
The VR23 anticancer proteasome inhibitor also exhibits anti-inflammatory activity through the downregulation of the IL-6-JAK-STAT pathway
Authors: Durkin Amanda , Lee Hoyun
Published: January 2023

We previously demonstrated that the novel proteasome inhibitor, VR23, possesses anti-tumor activity without causing any ill-effects to animals. We have now shown that the compound VR23 also possesses potent anti-inflammatory activity. Our data from a monocyte cell model shows that VR23 down-regulates pro-inflammatory cytokines IL-1β, TNF-α, IL-6, and IL-8 at similar efficacy as dexamethasone, a steroid widely used for the control of inflammatory conditions. Studies from a rheumatoid arthritis (RA) cell model show that VR23 can not only down-regulate IL-6 but also inhibit the cell migration. Importantly, the down-regulation of pro-inflammatory cytokines by VR23 is more pronounced in the primary synovial cells from RA patients than those from healthy donors. Since VR23 down-regulates not only STAT3 phosphorylation but also the expression of its downstream pathways, our data is consistent with the notion that VR23 exhibits its anti-inflammatory properties through the downregulation of the IL-6-JAK-STAT signaling pathway. The latter down-regulation is at the level of transcription of several important members of the IL-6-JAK-STAT family. Finally, VR23 effectively reduces neutrophil migration, TNF-α secretion, and tissue inflammation in mice with an LPS-induced acute lung injury. Our data thus suggest that VR23 is an agent with significant potential of controlling cancer as well as acute and chronic inflammatory conditions.
Tolerogenic nanoliposomes for the treatment of Rheumatoid Arthritis
Authors: Kenison-White Jessica , Nowakowska Dominika J , Jhaveri Aditi , Khase Nikita , Tezza Sara , Sherr David , Quintana Francisco Javier
Published: January 2023

Rheumatoid arthritis (RA) is a T-cell mediated chronic inflammatory disease characterized by inflammation of the synovial joints, and cartilage and bone tissue destruction. Therapeutic approaches for the induction of immune tolerance are of high clinical significance, and approaches aimed at controlling the balance of effector and regulatory T cells in an antigen-specific manner remain an unmet medical need. Based on its role in the control of the immune response, the ligand-activated transcription factor aryl hydrocarbon receptor (AhR) represents a strong candidate target for the development of novel immunotherapies. Here, we report the development of nanoliposomes (NLPs) which co-deliver a tolerogenic AhR ligand, ITE, and collagen type IIa. These NLPs ameliorated disease symptoms in the collagen-induced arthritis (CIA) model of RA in preventive and therapeutic treatment paradigms. CIA amelioration was associated with reduced levels of pro-inflammatory cytokines in the joints and decreased collagen type II specific IgG antibodies in serum. In addition, treatment with tolerogenic NLPs induced the expansion of FoxP3+ and IL10+ regulatory T cells and suppressed collagen-specific IFNγ+ effector T cells. Taken together, these results suggest that NLPs suppressed both T-cell and B-cell pathogenic responses and represent a novel therapeutic platform to induce antigen-specific tolerance for the treatment of autoimmune diseases.
Pneumocystis jiroveci pneumonia in rheumatoid arthritis patient treated with methotrexate but without prednisolone: A case report
Authors: Noh Jungwon , Han Seungtae
Published: January 2023

Background/Purpose

Methotrexate (MTX) is an anchor drug for rheumatoid arthritis (RA) if there is no contraindication. However, MTX can increase the risk of opportunistic infections including Pneumocystis jiroveci pneumonia (PCP) if combined with other immunosuppressive drugs such as prednisolone. Herein, we report a case of an RA patient who developed PCP during MTX treatment without prednisolone.

Methods

A 63-year-old woman with RA was admitted with high fever and shortness of breath. She had demonstrated stable RA activity after taking MTX 12.5 mg/week in addition to leflunomide 10mg daily for RA; however, about five months ago, she stopped taking low dose prednisolone. Computerized tomography (CT) of the chest demonstrated diffuse ground glass opacities in bilateral middle and lower lung fields. Laboratory examinations showed β-D-glucagon 140.2 pg/ml. A polymerase chain reaction (PCR) assay of bronchoalveolar lavage (BAL) fluid showed Pneumocystis carinii (PC). MTX and leflunomide were immediately discontinued. High dose trimethoprim/sulfamethoxazole (TMP-SMX) and methylprednisolone pulse therapy were administered. Following treatment, clinical and radiographic improvement were noted.

Results

The risk factors for RA-PCP have been reported by several studies. However, in this case, the patient had not taken prednisolone for more than five months before the occurrence of PCP and was considered low risk for PCP. In the RA patient, with or without risk factors, PCP should be considered in the differential diagnosis for respiratory infection and interstitial pneumonitis, including MTX-induced pneumonitis.

Conclusion

In the RA patient, MTX should be considered an important risk factor of PCP.
Generation of islet antigen-specific engineered Treg for use in T1D therapy via homology-directed gene editing of conventional CD4+ T cells
Authors: Yang Soo Jung , Singh Akhilesh , Cook Peter , Honaker Yuchi , Tappen Tori , Mauk Kelsey , Smith Jessica , Sommer Karen , Rawlings David J , Buckner Jane H
Published: January 2023

Adoptive transfer of regulatory T cells (Treg) is therapeutic in T1D mouse models. Notably, Treg specific for pancreatic islets are more potent than polyclonal Treg in blocking disease. However, the frequency of antigen-specific Treg is extremely low and ex vivo expansion has the potential to destabilize Treg leading to an effector phenotype. Here, we developed methods to generate durable, antigen-specific engineered (ed)Treg from primary human CD4+ T cells using a combination of lentiviral TCR transduction and FOXP3 homology-directed repair (HDR)-editing. Using TCRs derived from clonally expanded CD4+ T cells in T1D, we generated islet-specific edTreg that exhibit a Treg-like phenotype. Islet-specific edTreg effectively suppress proliferation and cytokine production by islet-specific effector T cells (Teff). Notably, edTreg suppress Teff recognizing the identical peptide as well as bystander Teff recognizing alternative islet antigens. Consistent with this, islet-specific edTreg suppress polyclonal islet-specific T cells derived from PBMC. Further, edTreg expressing TCR with high avidity have superior suppressive capacity to those expressing TCR with low avidity. To directly assess the capacity of edTreg to modulate T1D in vivo, we established an identical HDR-editing strategy in islet-specific murine cells. Adoptively transferred islet-specific mu-edTreg homed to the pancreas and blocked diabetes triggered by islet-specific Teff in recipient mice. Collectively, our approach enables the production of edTreg specific to pancreatic islets with the capacity to efficiently suppress islet specific responses. This approach has the capacity to deliver targeted islet specific therapy to treat or prevent T1D.