bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone marrow-derived RELMα regulates immunity and inflammation to gastrointestinal helminth Nippostrongylus brasilienis through effects on macrophages
Authors: Nair Meera G. 
Published: January 2023

Abstract
RELMα is a highly secreted protein in type 2 cytokine-induced inflammation including helminth infection and allergy. We previously showed that RELMα dampens Th2 immune responses to helminth Nippostronglyus brasiliensis (Nb). RELMα is expressed by immune cells such as macrophages, and by epithelial cells (EC), however, the functional impact of immune versus EC-derived RELMα is unknown. We generated bone marrow (BM) chimeras that were RELMα deficient (RELMα−/−) in BM or non BM cells and infected them with Nb. Non BM RELMα−/− chimeras had comparable inflammatory responses and parasite burdens to RELMα+/+ mice, suggesting that EC-derived RELMα does not significantly influence immune responses to Nb. In contrast, both RELMα−/− and BM RELMα−/−mice exhibited increased Nb-induced lung and intestinal inflammation, correlated with elevated macrophage responses, Th2 cytokines and Nb killing. CD11c+ lung macrophages were the dominant BM-derived source of RELMα and have been shown to mediate Nb killing. Therefore, we employed a macrophage-worm co-culture system to investigate whether RELMα regulates macrophage-mediated Nb killing. Compared to RELMα+/+macrophages, RELMα−/−macrophages exhibited increased binding to Nb and functionally impaired Nb development including decreased motility, growth and viability. Collectively, these studies demonstrate that BM- derived RELMα is necessary and sufficient to dampen Nb immune responses, and identify that one mechanism of action of RELMα is through inhibiting macrophage recruitment and interaction with Nb. Our findings suggest that RELMα acts as an immune brake that provides mutually beneficial effects for the host and parasite by limiting tissue damage and delaying parasite expulsion.
Splenocytes from young mice protect immunocompromised mice against death from malaria infection, but they do not proliferate well.
Authors: Opata Michael M. , Smith Margaret R. , Johnson Corey M. , Campbell Logan , Santos Hugo 
Published: January 2023

Abstract
The immune system plays an essential role in the elimination of malaria parasites. CD4+ T cells are imperative in the immune response to the infection, but immune response to malaria especially in young children is poorly understood, due to a lack of a better young animal model to study the pathogenesis of the disease. We have developed a young mouse (pup) model using day 15 pups to help understand the pathogenesis, and development of protective CD4 T cells in malaria infection. Here, we determined the ability of pup cells to protect immunocompromised RAGKO mice from malaria infection. We infected day 15 old pups with Plasmodium chabudi at 1×105 iRBCs, and transferred splenocytes to RAGKO mice on day 8 post-infection. RAGKO mice were then infected. Mice that received pup cells looked healthier and active throughout the experiment, compared to their counterparts who received adult spleen cells. During the peak of infection, mice that received adult cells lost more weight than the pup cell recipients. On day 60 post-transfer, we observed same numbers of CD4 T cells, central memory and effector memory T cells. There were significantly lower proportions and numbers of IFNγ and TNFα positive cells from pups compared to adult cells. We next determined if there was any difference in the proliferation of CD4 T cells and all splenocytes in pup cells. We purified CD4+ T cells using EasySep kit and cultured them on αCD3/CD28 pre-coated plates, compared to all splenocytes. There was a significant growth in purified CD4 T cells from adult than pup cells. Interestingly, all splenocytes from pups proliferated better than adults. Therefore, our data suggest that pup cells protect RAGKO mice from death, but do not develop into functional memory due to poor proliferation.
Cholera toxin requires microbiota metabolites short-chain fatty acids for its mucosal adjuvant activity
Authors: Yang Wenjing , Xiao Yi , Huang Xiangsheng , Chen Feidi , Chen Liang , Bilotta Anthony James , Xu Leiqi , Yao Suxia , Cong Yingzi 
Published: January 2023

Abstract
Cholera toxin (CT) is a potent mucosal adjuvant, however, the mechanisms by which CT induces both mucosal and systemic immune responses are still not completely understood. It has been shown recently that gut microbiota is critical in inducing immune response by CT, however, the mechanisms involved remain largely unknown. We demonstrated in this study that gut microbiota metabolites short-chain fatty acids (SCFA), which are solely metabolic products of gut microbiota from dietary fiber, are required for CT in inducing antigen-specific IgG and IgA responses after oral immunization. Depleting of gut bacteria by antibiotics significantly decreased mucosal and systemic IgG and IgA responses in mice orally immunized with ovalbumin (OVA) and CT. Feeding SCFA acetate and butyrate rescued antibody responses in antibiotics-treated WT mice. Furthermore, deficiency of GPR43, a SCFA binding receptor, impaired CT’s adjuvant activity. Acetate and butyrate did not directly act on B cells to promote IgG production, but promoted B cell IgG production and plasma B cell differentiation related genes in the presence of WT but not GPR43−/− DC. Furthermore, SCFA increased IgG production by both WT and GPR43−/− B cells when cultured with WT DC, indicating a crucial role for DC expression of GPR43 in SCFA induction of B cell IgG production. Mechanistically, SCFA promoted DC expressions of BAFF, a B cell activating factor, and Aldh1a2, an enzyme promoting production of retinoic acid (RA) from Vitamin A. Blockade either RA or BAFF signaling significantly inhibited SCFA induced B-cell IgG production. Therefore, our study indicated a critical role of gut microbiota and their metabolites SCFA in promoting the mucosal adjuvant activity of CT through partially GPR43.
Critical role for the microbiota in limiting inflammatory intestinal T cell responses
Authors: Kim Myunghoo , Galan Carolina , McAlester Andrea Hill , Wu Wan-Jung , Song Hyo Won , Littman Dan R. , Diehl Gretchen 
Published: January 2023

Abstract
Efficient functioning of the intestine and intestinal immune system depends on interactions between the host and microbiota. Breakdown in these interactions leads to reduced ability to respond to intestinal pathogens along with increased intestinal inflammation which together can lead to pathologic inflammatory conditions such as inflammatory bowel disease.
While a number of intestinal immune cells are likely regulated by the microbiota, we have found critical regulation of intestinal antigen presenting cells (APCs) expressing the chemokine receptor, CX3CR1. CX3CR1+ APCs are able to secrete both pro- and anti-inflammatory cytokines and are capable of mediating intestinal protection or pathology.
Using in vivo models, we identified a regulatory loop whereby intestinal CX3CR1+ APCs reduced induction of Th1 cells against intestinal pathogens and promoted generation of regulatory T cells against soluble food antigens and the microbiota itself. This regulatory response depends on anti-inflammatory cytokine IL-10 production by CX3CR1+ APCs. Disruption of the intestinal microbiota switched the functional capacity of CX3CR1+ APCs so they now drove inflammatory Th1 responses and mediated pathology in a model of colitis. Mechanistically, we determined that epithelial attachment by intestinal microbes was required to turn on anti-inflammatory functions by CX3CR1+ APCs. Our results identify a cellular mechanism by which the microbiota limits intestinal inflammation and promotes homeostasis. Our study demonstrates the potential therapeutic benefits of microbiota and host immune cell manipulation with the goal of amplifying or inhibiting intestinal T cell responses.
HDAC10 Targeting Regulates Foxp3 Promoter, Enhances T-regulatory (Treg) Function and Suppresses Autoimmune Colitis
Authors: Dahiya Satinder , Wang Liqing , Beier Ulf H. , Han Rongxiang , Hancock Wayne W. 
Published: January 2023

Abstract
Targeting histone/protein deacetylases (HDACs), especially by isoform-selective targeting, has major promise as a means to enhance the function of Tregs and thereby suppress immune-related disorders, such as colitis. We present data on the functions of HDAC10 in Treg cells. We found that HDAC10 binds to the Foxp3 promoter in the Tregs, is able to physically bind and deacetylate Foxp3 (at K31), and regulates the transcriptional activity of the Foxp3 promoter. Next, we evaluated the function of HDAC10 using HDAC10 KO mice. Overall, such mice were healthy and HDAC10 deletion: (i) enhanced Treg suppressive function both in vitro (Treg suppression assays) and in vivo (homeostatic proliferation assays), compared to wild-type (WT) Tregs; (ii) modestly enhanced the stability of monomeric Foxp3 (reducing gels) but the oligomeric forms, which are more relevant functionally, were increased by more than two-fold (native gels); (iii) increased H3K4Me3 (activating) marks on Foxp3 promoter and the key regulatory region of Foxp3 promoter-CNS2; and (iv) enhanced binding of ATF/CREB and FoxO1 at the Foxp3 promoter and CNS2 sites. We then evaluated the effects of HDAC10 deletion in Tregs in colitis models using adoptively transferred Rag1 KO mice. We found that HDAC10 KO Tregs were superior to WT Tregs in: (i) a ‘prevention of induction’ model of colitis, whereby WT T effector cells were injected with a limiting ratio of Tregs that allowed for weight loss as an indicator of colitis; and (ii) rescuing from colitis. Studies to develop and test HDAC10-specific inhibitors are currently underway. Overall, we show that HDAC10 has a key role in Foxp3+ Treg cells, and is an important new target for therapeutic intervention in autoimmune diseases, including colitis.
Epigallocatechin-3-gallate (EGCG) ameliorates dextran sulfate sodium (DSS) –induced inflammatory bowel disease
Authors: Payan Brittany A. , Vanarsa Kamala , Ding Huihua , Soomro Sanam , Baig Sahar , Du Yong , Hicks John , Mohan Chandra 
Published: January 2023

Abstract

Background
Given the potential side effects associated with conventional medical treatment of Inflammatory Bowel Disease (IBD), dietary supplements have been investigated by several groups. We tested if epigallocatechin gallate (EGCG) may be beneficial in IBD.

Methods
36 C57BL/6J mice were subjected to dextran sulfate sodium (DSS)-induced IBD and divided into 3 groups: model group (MD; no EGCG), low dose EGCG group (LE, 20 mg/kg/d) and high dose EGCG group (HE, 50 mg /kg/d).

Results
Both high and low dose EGCG treatment alleviated clinical manifestations of IBD including body weight loss and disease activity index (DAI): HE: 3.3 and LE: 2.8 vs. 8.3 in MD (p &lt; 0.001, n=8–10 mice/group). Macroscopic severity score (MSS) of HE and LE groups were 2.4, and 2.2, respectively, significantly lower than in MD (5.0, P &lt; 0.01). The mean colon length of MD group was 5.8 cm; treatment with EGCG restored colon length (HE: 6.5 cm; LE: 6.4 cm). Intestinal permeability was improved as demonstrated by FITC-Dextran assay (HE: 3.28; LE: 2.85, vs. MD group: 6.69 ng/ml, P &lt; 0.001) .The colitis histology score of HE (1.54) and LE (0.42) groups were significantly lower than that in MD (4.3, P &lt; 0.001). In addition, EGCG treatment reduced colonic levels of pro-inflammatory cytokines: IL-6 (HE: 0.45; LE group: 0.41 vs MD: 0.89 ng/g tissue, P =0.03), MCP-1 (HE: 1.83; LE: 1.87, vs MD: 3.5 ng/g tissue P = 0.01) and TNF-alpha (HE: 8.87; LE: 10 vs MD: 21.7 ng/g tissue, P &lt;0.001). Lower CD3+ T cell and CD68+ macrophage infiltration was also noted in HE and LE mice (P &lt; 0.001), compared to MD controls.

Conclusion
These results underscore the therapeutic potential of EGCG in the treatment of IBD, which appear to be mediated through multiple inflammatory pathways.
Anti-inflammatory activity of the piperazino-enaminone JODI-19 in vitro and in vivo
Authors: Szollosi Doreen , Sun Junjiang , Ghoneim Ola , Bill Ashley , Edafiogho Ivan 
Published: January 2023

Abstract
Data to characterize novel anti-inflammatory agent enaminone E121 have shown a marked decrease in the release of pro-inflammatory cytokines in macrophages stimulated with lipopolysaccharide (LPS) compared to the control (DMSO) group. Literature has described that when an N-alkylated piperazine motif is added to the terminal end of the lead compound, it is able to increase the CCR2 antagonistic activity. We hypothesized that incorporating the N-alkylated piperazine motif into the existing E-121 enaminone pharmacophore could lead to a ligand with dual functionality as a cytokine inhibitor and chemokine receptor antagonist. The resultant series (JODI) were studied in vitro, and data suggest they can suppress TNF-alpha and IL-6 in a dose-dependent manner, superior to that of dexamethasone. Additionally, macrophages stimulated with chemokine MCP-1 and treated with JODI compounds, (but not E121), are able to block CCR2 signaling as evidenced by decreased total ERK1/2. To determine if JODI-19 has activity in vivo, it was utilized in a mouse model of hemarthrosis to assess decreased inflammation as evidenced by local cytokine suppression. In a pilot study, FIX−/−mice were subjected to hemarthrosis induction with or without JODI administration. At different timepoints from four hours to four weeks after hemarthrosis, synovial fluid was collected by lavage for multiple cytokine analyses. Administration of JODI-19 significantly decreased TNFα, IL-1α, MCP-1 and MIP-1α levels in the synovial fluid. As such, JODI-19 may be a novel approach to better manage hemophilia arthropathy and its associated bone damage.
Syngeneic stem cell transplantation generates antigen-specific T cells that maintain myeloma-immune equilibrium
Authors: Minnie Simone , Vuckovic Slavica , Smith David , Gartlan Kate H. , Watkins Thomas S. , Kuns Rachel D. , Guillerey Camille , Chesi Marta , Markey Kate A. , Miles John J. , Smyth Mark J. , Hill Geoffrey R. 
Published: January 2023

Abstract
Multiple myeloma (MM) is a largely incurable hematological malignancy characterized by clonal expansion of plasma cells in bone marrow (BM). Autologous stem cell transplantation (ASCT) remains a standard treatment for MM, allows intensive cytoreduction and induces inflammation in the context of lymphodepletion. We hypothesized that SCT may overcome myeloma-induced immune defects to restore immune-equilibrium. To address this, we developed a model of ASCT for MM using Vk*MYC myeloma. Surprisingly, we demonstrate the induction of T cell-dependent MM control after SCT as recipients of syngeneic BM grafts containing T cells had prolonged survival and reduced tumor burden compared to BM alone. This anti-myeloma activity was independent of γδ T, natural killer (NK) and NK T cells and was dependent on CD4+and CD8+ T cells. MM-primed T cells, harvested from SCT recipients with controlled MM, protected against relapse in secondary recipients and were Vk*MYC clone-specific. Recipients of MM-primed T cells had increased central memory CD8+ T cells and transfer of MM-primed CD8+ T cells was sufficient to prevent relapse. Furthermore, TCR sequencing of CD8+ T cells from mice with controlled MM revealed a higher clonotype overlap relative to MM-free SCT recipients, consistent with MM-specific T cells. Donor IFNγ secretion and signaling was critical to protective immunity and CD8+ T cells from mice with relapsed MM had impaired IFNγ production compared to those with controlled disease. Importantly, IFNγ production was profoundly augmented by CD137 agonist treatment such that majority of mice controlled disease. These data provide new insights into the mechanisms of action of SCT in myeloma and suggest the use of CD137 agonists to prevent relapse.
Aquaporin 4 blockade alters T cell trafficking through a novel mechanism of S1PR1 regulation.
Authors: Nicosia Michael , Fan Ran , Miyairi Satoshi , Farr George W. , McGuirk Paul R. , Pelletier Marc F. , Beavers Ashley , Valujskikh Anna 
Published: January 2023

Abstract
The water channels aquaporins mediate a variety of immune functions. We previously demonstrated that aquaporin 4 (AQP4) is expressed by CD4 and CD8 T cells and blockade of AQP4 with small molecule inhibitor AER-270/271 significantly prolongs survival of heart allografts in two robust models of rejection. The goal of this study was to determine the effects of AQP4 blockade on T cells.
Administration of AER-271 into naïve non-transplanted mice (250 μg i.p. every 6 h on d. 0–4) decreased numbers of circulating CD4 and CD8 T cells, but not B cells, by &gt;90%, compared to untreated controls. The T cell frequencies and numbers in the secondary lymphoid organs (SLOs) were not significantly affected by AER-271, suggesting the lack of circulating T cells is not due to systemic depletion but rather to altered T cell trafficking.
The effect of AER-271 treatment was transient, as circulating T cell numbers returned to pretreatment levels by d 21. AER-271 treated animals promptly rejected heart allografts transplanted 24 d after treatment cessation (MST 6 d, n=4).
We next tested the effects of AQP4 blockade on Sphingosine-1 Phosphate Receptor 1 (S1PR1), a key mediator of T cell trafficking. S1PR1 mRNA expression was reduced in isolated mouse spleen T cells within 3 h of in vitro incubation with AER-270. Decreased S1PR1 mRNA expression translated into altered chemotaxis, as AER-270 reduced T cell migration toward S1PR1 ligand, Sphingosine-1 Phosphate (S1P), in a transwell system.
Our data suggest that AER-270/271 treatment results in altered S1PR1 transcription thus changing T cell trafficking and prolonging allograft survival. Therefore, AQP4 blockade may be an attractive therapeutic strategy in transplantation and other immune-mediated diseases.
Lack of B10 and MZ-like B cells in liver-transplant patients with PCH
Authors: Hasan Md Mahmudul , Thompson-Snipes LuAnn , Klintmalm Göran B. , Oh Sangkon , Joo HyeMee 
Published: January 2023

Abstract
Human CD24hiCD27+ B cells subset, also known as B10, is a mixture of marginal zone (MZ)-like B cells (IgD+CD27+) and memory B cells (IgD−CD27+), and can protect against autoimmune/inflammatory damage, in part, by producing IL-10, an anti-inflammatory cytokine. However, the role of B10 and MZ-like B cells in solid organ transplantation is poorly understood. In this study, we examined IL-10-producing human B cells subsets including MZ-like B cells, memory B cells and transitional B cells (CD24hiCD38hi) in the blood of healthy controls compared to liver transplant patients with plasma cell hepatitis (PCH), a variant of late onset rejection. First, we phenotypically and functionally characterized different human B cells subsets that produce cytokine IL-10 in several human tissues including tonsil and spleen, and PBMC. Then, we demonstrated that CD24hiCD27+ B cell is the major source of IL-10 producing cells and capable to suppress alloantigen stimulated T cell proliferation and cytokine production in IL-10 dependent manner. We also found that the frequency of CD24hiCD27+ B, as well as IgD+CD27+MZ-like B cells is significantly lower in PCH+ liver transplanted patients than healthy controls. In line with this, the frequency of IL-10+CD19+ B cells is negligible in PCH+ liver transplant patients compared with healthy controls upon CpG B stimulation. Our findings suggest that a lack of immunosuppressive IL-10 producing B cell subsets could be associated with the rejection in the PCH+ patients.
Antigens Associated with Non-HLA Cardiac Transplant Rejection
Authors: Gates Katherine , Griffiths Leigh 
Published: January 2023

Abstract
Despite advances in management of acute rejection episodes, rejection incidence remain largely unchanged in heart transplant patients. While Human Leukocyte Antigen (HLA) is a common initiator of graft-specific immune responses, cases of non-HLA antibody mediated rejection (AMR) also commonly occur. Identification of non-HLA antigens is therefore critical to increasing understanding of heart transplant rejection. We hypothesize that cardiac non-HLA antigens contribute to AMR and novel proteomic techniques can be utilized to identify multiple antigens simultaneously. Serum from heart transplant patients was collected longitudinally at pre-operation (T1), acute rejection (T2), and post-rejection (T3) time points. Protein was extracted from biopsies of each patient’s donor heart. Human IgG antibodies were isolated with Protein G HP SpinTraps. Resultant human anti-human heart affinity columns were utilized to capture antigenic proteins from individual patient’s heart protein extracts. Proteins eluted from columns were subjected to LC-MS/MS analysis. Proteins were considered antigenic if they significantly increased relative to T1 samples using Gaussian linearized modeling. Non-HLA graft specific antibodies were found to increase at T2 and T3 in all patients. At T2, 82 antigens were identified with a population frequency of 33 to 83%. Over 50% of antigenic proteins were associated with action potential, contractile function, endothelial dysfunction, and other causes of cardiac allograph vasculopathy. The cardiac non-HLA antigens identified in this study further understanding of the immunological mechanisms of transplant rejection and have potential to be utilized as biomarkers for cardiac allograft dysfunction.
Display of CD47 protein on pancreatic islet grafts improves engraftment following intraportal transplantation
Authors: Shrestha Pradeep , Bowen William S. , Batra Lalit , Tan Min , Yolcu Esma S. , Shirwan Haval 
Published: January 2023

Abstract
Intraportal islet transplantation is a curative therapy for type 1 diabetes. However, early islet engraftment is hampered by a thrombotic and inflammatory reaction defined as an instant blood-mediated inflammatory reaction (IBMIR). The CD47 molecule is an important regulator of IBMIR, by blocking phagocytosis. We hypothesized that the transient display of the CD47 protein on the surface of islet grafts may prevent early islet destruction by IBMIR following intraportal transplantation. We generated a chimeric CD47 fused with a modified streptavidin (SA-CD47). SA-CD47 was transiently displayed on the surface of rat splenocytes that had been modified with biotin taking advantage of the strong affinity between biotin and streptavidin (SA). SA-CD47 protein was also effectively displayed on the surface of biotinylated islets. Importantly, in a syngeneic marginal mass intraportal islet transplantation model, 7/8 streptozotocin-diabetic C57BL/6 mice transplanted with 125 SA-CD47 engineered islets established euglycemia long term (&gt;80 days). In marked contrast, only 1/7 mice achieved euglycemia when transplanted with SA-engineered islet grafts. The engrafted islets in the SA-CD47 group had a comparable response to naïve mice in the intraperitoneal glucose tolerance test. Flow cytometric and qRT-PCR analyses of liver tissues did not reveal significant changes in cellular and molecular immune responses between SA-CD47 and SA-engineered control groups, suggesting that inhibition of islet phagocytosis as underlying mechanism of islet engraftment and survival. Collectively, these results demonstrate the utility of SA-CD47 as a regulator of IBMIR for prevention of early islet graft loss following intraportal transplantation