bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune regulation of tissue-expressed B7x and B7-H1 (179.10)
Authors: Zang Xingxing 
Published: January 2023

Abstract
Some B7 family members are expressed in peripheral cells but their in vivo functions remain largely unknown. Here we showed that B7x protein (B7-H4 or B7S1) was not expressed in human or murine immune cells, but was expressed in some peripheral cells such as pancreatic β cells and lung epithelial cells. Using knock-out and transgenic mice, we found that B7x in pancreatic β cells inhibited autoimmune CD8 or CD4 T cell-mediated diabetes, whereas B7x in lung epithelial cells contributed to tumor metastasis and lethal pulmonary infection. B7-H1 (PD-L1) is widely expressed in immune cells and is important in the coinhibition of T cell function via binding its receptor PD-1. We showed that both human and mice intestinal epithelium expressed B7-H1 and mice deficient for B7-H1 were highly susceptible to gut injury and associated mortality and morbidity. Defective B7-H1 led to loss of epithelial integrity and systemic dispersion of commensal bacteria during intestinal inflammation. B7-H1 expressed on parenchymal cells but not on hematopoietic cells controlled intestinal inflammation, which was not dependent on PD-1, B7-1, and the adaptive immunity. Taken together, all these findings suggest that tissue-expressed B7x and B7-H1 critically control immune response and inflammation.
Tr17: a unique subset of T regulatory cells that produce IL-17 and display potent suppressive function (179.11)
Authors: Li Lequn , Patsoukis Nick , Petkova Victoria , Boussiotis Vassiliki 
Published: January 2023

Abstract
Immune suppression by T regulatory (Treg) cells is required for peripheral T cell tolerance. Treg cells display plasticity and are subjected to regulation by other immune cells. We determined previously that co-culture of CD4+CD25- cells and Treg cells in the presence of antigen presenting cells induced Treg cells producing IL-17 (named Tr17 cells). In the present study, we investigated the conditions required for the generation of Tr17 cells and we analyzed their molecular and functional properties. We determined that both IL-1β and IL-2 were required for the development of Tr17 cells. Compared to IL-17- Treg cells, Tr17 cells expressed increased levels of RORγt and Runx1 while retaining expression of Foxp3. To gain insight into how IL-17 transcription is regulated in Treg cells, we performed CHIP assays and found that Runx1 was able to bind to the IL-17 promoter and enhancer. Tr17 cells displayed more potent suppressive activity compared to IL-17- Treg and responder cells co-cultured with Tr17 cells were more prone to cell death than those co-cultured with IL-17- Treg. Tr17 cells expressed increased levels of perforin and granzyme B relative to IL-17- Treg and used this pathway to induce killing of responder cells as determined by degranulation assay. Our findings suggest that Tr17 cells represent a subset of Treg cells that is generated under inflammatory conditions and may have a unique role in suppressing inflammatory responses by inducing effector cell killing.
TGF-β-induced CD4+ regulatory T cells but not nTregs ameliorate autoimmune arthritis by shifting the balance between Tregs and Th17 cells In vivo (179.14)
Authors: Zheng Song Guo , Kong Lin , Lan Qin , Chen Maogen , Wang Julie , Horwitz David , Brand David , Ryffel Bernhard 
Published: January 2023

Abstract
Transferred CD4+CD25+Foxp3+ regulatory cells (Tregs) can prevent autoimmune disease, but generally fail to ameliorate established disease. Here we demonstrate that antigen-specific Tregs induced with IL-2 and TGF-β ex-vivo (iTregs), but not equivalent expanded thymus-derived nTregs can prevent progression of established collagen-induced arthritis. This was because following transfer, nTregs exhibited decreased Foxp3 and Bcl-2 expression, decreased suppressive activity, and many converted to Th17 cells. By contrast, transferred iTregs were more numerous, retained their suppressive activity in the presence of IL-6 and were resistant to conversion. Remarkably, ten days after transfer iTregs shifted the predominance from Th17 to Treg cells in draining LNs. These findings provide evidence that transferred TGF-β-induced iTregs are more stable and functional than nTregs in mice with established autoimmunity. Moreover, iTregs can have tolerogenic effects even in the presence of ongoing inflammation. The therapeutic potential of iTregs in subjects with chronic, immune-mediated inflammatory diseases deserves to be investigated.
Alternate function of Foxp3 in human CD4+ T cells (179.2)
Authors: Martin Sunil , Riley James 
Published: January 2023

Abstract
Foxp3 is the master regulator of T-reg phenotype and function. Unlike murine T cells, human T cells express two versions of Foxp3 of which the smaller form is missing exon 2 (Δ2). Previously we showed that Foxp3Δ2 fails to up-regulate the Pim 2 kinase and others have reported that members of the ROR family bind to exon 2 of Foxp3. Nonetheless, it is not clear if these isoforms differentially affect regulatory and nonregulatory T cell function. This study demonstrate that transduction of Foxp3 and Foxp3Δ2 into primary human CD4+CD45RA+CD25- naïve T cells induced suppressive activity that was identical to natural T-regs. However, in CD4+CD45RA-CD25- memory T cells, the full-length Foxp3 construct was unable to introduce a suppressive phenotype, whereas Foxp3Δ2 retained its ability to promote suppressive activity. Furthermore, memory cells transduced with Foxp3 abrogated the suppressive functions of naïve cells transduced with Foxp3 but not with Foxp3Δ2.Cytokine profiling indicated a 3 fold increase in the IL-2+IFN-γ+ cells within the memory cells transduced with Foxp3. Altogether these observations reveal an isoform dependent alternate function of Foxp3 in the CD4+ memory T cell compartment. These studies support the use of naïve T cells for strategies that transduce effector T cells with Foxp3 expressing vectors as a means to rapidly generate T-regs for use in adoptive T cell therapy against autoimmune diseases.
Alpha7 cholinergic-agonist prevents systemic inflammation by Sepsis. (179.3)
Authors: Thompson-Bonilla Maria del , Vida Gergely , Pena Geber , Ulloa Luis 
Published: January 2023

Abstract
The alpha7 nicotinic acetylcholine receptors (α7nAChR) play a critical role in modulating systemic inflammation in sepsis (1). However, α7nAChR-agonists have failed to provide significant advantages in several pilot studies with septic patients. Since we recently reported that the vagus nerve prevents sepsis by activating regulatory lymphocytes (2), we reasoned that the massive apoptosis of lymphocytes during sepsis may prevent the therapeutic effects of the α7nAChR-agonists. Our results indicate that α7nAChR-agonists failed to prevent systemic inflammation in lymphocyte-deficient nude mice. The transfer of typical regulatory CD3+CD4+CD25+ suppressor/regulatory lymphocytes failed to reestablish the benefits of α7nAChR-agonists. But, the transfer of CD3+CD4+CD25- modulatory lymphocytes reestablished the anti-inflammatory potential of the α7nAChR-agonists. Likewise, α7nAChR-agonist prevented systemic inflammation in polymicrobial sepsis when administered before sepsis. The anti-inflammatory potential and benefits of the α7nAChR-agonists vanishes as the treatment is delayed after the onset of the infection. However, the adoptive transfer of CD3+CD4+CD25- modulatory lymphocytes reestablished the anti-inflammatory potential of the α7nAChR-agonists, even if the treatment is started long after the infection. These results suggest that a new set of CD25- modulatory lymphocytes can provide clinical advantages for the treatment of infections and inflammatory disorders.
Role of class IA PI3K in regulatory T cell function (179.5)
Authors: Fujii Hideki , Matsuda Satoshi , Ohtani Masashi , Koyasu Shigeo 
Published: January 2023

Abstract
PI3K (phosphoinositide 3-kinase) family members control variety of cellular responses, such as cell growth, survival, cytoskeletal remodelling and the trafficking of intracellular organelles, in many cell types, including T lymphocytes. The PI3K pathway has emerged as a key regulator of regulatory T cell (Treg) development and homeostasis and may be required for Treg-mediated suppression. To identify the role of regulatory subunits of class IA PI3K in Treg suppressive function, we compared WT and p85α KO Tregs in their function. WT but not p85α KO Tregs showed suppressive capacity in co-cultures with CD4+CD25- T cells stimulated with anti-CD3-coated APCs in vitro. To determine whether p85α KO Tregs were functional in vivo, we conducted experiments in which Tregs offer protection from colitis caused by the transfer of CD4+CD62L high T cells into RAG2-/- recipients. WT Tregs suppressed the capacity of CD4+CD62L high T cells to cause colitis 2 weeks after transfer. In contrast, mice co-injected with p85α KO Tregs developed colitis 2 weeks after transfer that was indistinguishable from that in mice injected with CD4+CD62L high cells alone. Although the precise mechanism of Treg-mediated suppression is unclear, we suppose that p85α functions through cell-cell contact-dependent manner rather than cytokine-dependent manner. S.K. is a consultant for Medical and Biological Laboratories, Co. Ltd. The authors otherwise have no financial conflicts of interest.
Inhibition of TLR Signaling by TIRAP/Mal-derived Decoy Peptides (180.14)
Authors: Toshchakov Vladimir , Couture Leah , Piao Wenji , Ru Lisa , Vogel Stefanie 
Published: January 2023

Abstract
TIRAP/Mal is an adapter protein that facilitates recruitment of MyD88 to TLR4 and TLR2 signaling complexes. We have previously generated a library of cell-permeating TLR4 TIR-derived decoy peptides fused to the translocating segment of Drosophila antennapedia homeodomain and examined each peptide for the ability to inhibit TLR4 signaling. To expand previous studies we now have generated TIRAP-derived peptides and tested them for the ability to inhibit TLR2 and TLR4 signailng. Five TIRAP peptides, TR3, TR5, TR6, TR9, and TR11, inhibited LPS-induced cytokine mRNA expression and MAPK activation. Inhibition was confirmed at the protein secretion level, as select peptides abolished the LPS-induced cytokine production measured in macrophage supernatants collected 24 h after LPS stimulation. Two TIRAP inhibitory peptides, TR3 and TR6, also inhibited cytokine production induced by a TLR2/TLR1 agonist, S-[2,3-bis(palmitoyloxy)-(2-RS)-propyl]-N-palmitoyl-(R)-Cys-Ser-Lys4-OH (P3C); however, a higher peptide dose was required to achieve TLR2 inhibition. TR3 and TR6 did not block macrophage activation induced by TLR2/6 agonist, S-[2,3-bis(palmitoyloxy)-(2-RS)-propyl]-[R]-Cys-Ser-Lys4-OH (P2C). This study has identified novel peptides that block TLR signaling at low micromolar concentrations. Comparison of TLR4 inhibition by TLR4 TIR- and TIRAP-derived peptides suggests that structurally diverse regions mediate functional interactions of TIR domains.
Development of inhibitory peptide to control TLR9 signaling pathway. (180.17)
Authors: Singh Sujay , Lee Hyun-Ku , Singh Gita , Luo Yi Feng , Chitta Sriram , Rosenberg Jonathan 
Published: January 2023

Abstract
Toll-like receptors (TLRs) play an important role in sensing microbial molecules. Upon recognition of microbial components, TLRs quickly engage with their adaptors and initiate innate immune signals by sequentially recruiting downstream signaling mediators, which provide immediate host protection and stimulate the host’s adaptive immune response. Despite the fact that TLR-mediated innate immune signals are required to combat invading pathogens, when signaling is not well regulated, uncontrolled activation can result in the disruption of host homeostasis leading to chronic inflammation and septic shock. Although there are naturally occurring negative regulators of TLR signaling that function as part of cell homeostasis, these are not adequate in all situations. Hence development of a targeted therapeutic means or molecule that can effectively control TLR-mediated chronic inflammation is crucial. In response to this, we have developed a synthetic peptide based on a CpG-binding motif in the extracellular domain of TLR9, which can inhibit TLR9 signaling. Using TLR9/NF-κB/SEAPorter™ HEK 293 cell line, the inhibitory peptide was validated together with a control peptide in which conserved residues were modified. The inhibitory peptide significantly suppressed CpG-mediated TLR9 activation while the control peptide did not affect TLR9 activation. Test of another peptide with differential residue modification further revealed the key residues involved in CpG-mediated TLR9 activation.
R753Q polymorphism compromises TLR2 signaling functions by altering TLR6-TLR2 hetero-dimerization, TLR2 tyrosine phosphorylation and MyD88 recruitment (180.2)
Authors: Xiong Yanbao , Song Chang , Medvedev Andrei 
Published: January 2023

Abstract
TLR2 senses lipoproteins expressed by Gram positive bacteria, mycoplasma, mycobacteria and fungi. The Arg753Gln (R753Q) polymorphism in the TIR domain of TLR2 has been linked to increased incidence of tuberculosis, leprosy and other diseases. But the molecular mechanisms by which it affects TLR2 functions are unclear. We studied the impact of complementation of HEK293 cells and mouse TLR2-/- macrophages with wild-type (WT) vs. R753Q TLR2 on TLR2 expression, interactions with TLR6, tyrosine phosphorylation, recruitment of MyD88, and functional responses. Transfected WT and R753Q TLR2 variants had comparable expression, and even 100-fold increase in input amounts of R753Q vs. WT TLR2 did not overcome deficiency of the mutant receptor. R753Q TLR2 exhibited deficient agonist-induced tyrosine phosphorylation, hetero-dimerization with TLR6 and recruitment of MyD88. R753Q TLR2 mediated impaired activation of p38, NF-κB, and induction of IL-8 mRNA in response to inactivated Mycobacterium tuberculosis, mycobacteria cell wall, culture filtrate fractions, lipoarabinomannan and Pam3Cys. In contrast, stimulation with TNF-α led to similar NF-κB reporter activation and IL-8 gene expression in cells expressing wild-type or R753Q TLR2. These results revealed deficient TLR2 tyrosine phosphorylation, hetero-dimerization with TLR6 and recruitment of MyD88 as key features underscoring signaling deficiency of the R753Q TLR2.
Enhanced Glycogen Synthase Kinase 3β phosphorylation modulates leukocytes Toll-like receptor-mediated cytokine secretion in obese people. (180.7)
Authors: Yen Chia-Liang , Chang Chin-Sung , Wu Chih-Hsing , Shieh Chi-Chang 
Published: January 2023

Abstract
Obesity is an increasing modern disease which leads to type II diabetes mellitus and cardiovascular diseases. However, the impacts of obesity on immune function and infectious diseases have not been fully understood. To clarify the role of obesity in the immune responses, we investigated the relationship between insulin-induced signaling and Toll-like Receptors (TLRs)-induced leukocyte cytokine secretion in obese subjects. We found decreased TLR-induced IFN-γ, IL-6 secretion and elevated TLR-induced IL-1β, IL-10 secretion by leukocytes isolated from obese subjects when compared with normal leukocytes. Peripheral blood mononuclear cells (PBMCs) from obese subjects showed enhanced basal Akt/Glycogen Synthase Kinase 3β (GSK3β) phosphorylation which was not further increased by insulin and lipopolysaccharide (LPS). Leukocytes isolated from obese subjects also showed increased IκB level. We further investigated the role of GSK3β on LPS-induced cytokine secretion and NF-κB activation in THP-1 cells under hyperinsulinemic and hyperlipidemic conditions. We found that insulin and palmitate stimulation can increase GSK3 phosphorylation and IκB level. We also found that insulin stimulation and GSK3β siRNA knockdown can increase IκB level and IL-10 secretion. We conclude that enhanced leukocyte GSK3β phosphorylation may contribute to aberrant immune response in obese subjects.
Pivotal roles of both Wiskott-Aldrich syndrome protein (WASP) and N-WASP in the activation and attenuation of the B cell receptor (P1093) (42.1)
Authors: Liu Chaohong , Sharma Shruti , Miller Heather , Upadhyaya Arpita , Dahlberg Carin , Westerberg Lisa , Snapper Scott , Song Wenxia 
Published: January 2023

Abstract
Lymphocytes express both Wiskott-Aldrich syndrome protein (WASP) and N-WASP. WASP deficiency, the cause of WAS, generates more severe defects in T-cells than B cells, suggesting a strong compensatory role of N-WASP in B cells. Using knockout mouse models, this study shows that WASP knockout (WKO) reduces B cell spreading, B cell receptor (BCR) aggregation, tyrosine phosphorylation, Btk phosphorylation and F-actin accumulation at the B cell surface induced by membrane-associated antigen, and WASP/N-WASP double knockout nearly abolished these activities. However, in B cells with N-WASP conditional knockout (cNKO), B cell spreading and F-actin accumulation are enhanced, while the merge of BCR aggregates and attenuation of tyrosine and Btk phosphorylation are inhibited. Additionally, cNKO has a much stronger inhibitory effect on BCR endocytosis than WKO. In contrast to Btk-dependent activation of WASP, N-WASP phosphorylation is upregulated by Btk-deficiency but downregulated by SHIP KO. Furthermore, the phosphorylation of WASP and N-WASP is inversely regulated by each other. These results reveal that the combined function of WASP and N-WASP is required for the optimal activation of the BCR and its signaling attenuation, but these two proteins function distinctively: WASP and N-WASP play dominant roles in the initiation and attenuation of BCR activation respectively. Thus, the integrated action of WASP and N-WASP provide a critical regulatory mechanism for BCR activation.
Transcriptional regulation by 2,3,7,8-tetrachlorodibenzo-ρ-dioxin within the human polymorphic hs1,2 enhancer (42.7)
Authors: Liu Jing , Ochs Sharon , Sulentic Courtney 
Published: January 2023

Abstract
The environmental contaminant 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD) inhibits Ig expression and secretion. Within the IgH gene, the 3’IgH regulatory region (3’IgHRR) has been identified as a transcriptional target of TCDD. TCDD inhibits mouse 3’IgHRR and induces aryl hydrocarbon receptor (AhR) binding to dioxin response elements (DREs) within the hs1,2 and hs4 enhancers. The human hs1,2 enhancer is polymorphic due to the presence of one to four invariant sequences (IS) which have been correlated with several autoimmune disorders. Interestingly, TCDD inhibits the transcriptional activity of the mouse hs1,2 enhancer, while the human polymorphic hs1,2 enhancer activity is increased. Several transcription factor binding sites are located within both the mouse and human hs1,2 enhancers, while others are only in the mouse or human. Thus, we hypothesize that the specific transcription factor within the mouse and the human enhancers lead to differential effects by TCDD. Our data show that insertion of Pax5, deletion of the whole IS, or mutation of the AP-1/Ets site outside the IS decreases overall transcriptional activity. However, mutation of the transcription factor binding sites within the IS or the Oct site outside the IS increase the transcriptional activity. These results underscore the complexity of the transcriptional regulation of the hs1,2 enhancer and suggest an interaction between multiple transcription factors, many of which have been shown to be modulated by TCDD.
Structurally identical capsular polysaccharide expressed by intact group B Streptococcus versus Streptococcus pneumoniae elicits distinct murine polysaccharide-specific IgG responses in vivo (43.10)
Authors: Arjunaraja Swadhinya , Paoletti Lawrence , Snapper Clifford 
Published: January 2023

Abstract
Our previous studies using intact Streptococcus pneumoniae type 14 (Pn14) (Gram-positive) and Neisseria meningitidis (Gram-negative) indicated distinct differences in the regulation of the associated polysaccharide (PS)-specific IgG responses. In light of potentially unique contributions of biochemically distinct capsular PS and their characteristic attachments to the underlying bacterium, it remains unresolved whether different bacterial sub-capsular domains can exert differential effects on PS-specific Ig responses. In this study, we utilized a mutant strain of group B Streptococcus (S. agalactiae) type III (GBS-III) that expresses desialylated IIIPS, biochemically identical to type 14 capsular PS (PPS14) of Pn14, to directly compare the PPS14-specific IgG responses to two distinct Gram-positive bacteria. Although both GBS-III and Pn14 elicited relatively rapid primary IgG anti-PPS14 responses that were dependent on CD4+ T cells, CD40L and CD28 costimulation, only GBS-III induced a highly boosted ICOS-dependent PPS14 specific IgG response. Of note, priming with Pn14 and boosting with GBS-III, although not isolated PPS14, elicited a similarly boosted PPS14-specific IgG response that was T cell- dependent. This indicates that Pn14 primes for memory but, unlike GBS-III, fails to elicit it. These data establish that structurally identical capsular PS expressed by two distinct Gram-positive extracellular bacteria can indeed elicit distinct PS specific IgG responses.
Th17, Th22 and regulatory T cells are essential for controlling parasite burden and mucosal inflammation during Toxoplasma gondii infection (43.11)
Authors: Fonseca Denise , Benevides Luciana , Souza Maria do Carmo , Bonfá Giuliano , Solano-Dias Murilo , Basso Alexandre , Silva Neide , Mineo Tiago , Ryffel Bernhard , Silva João 
Published: January 2023

Abstract
The Toxoplasma gondii infection induces intense intestinal inflammation and tissue damage in susceptible hosts. Here, we studied the regulation of immune response during intestinal mucosal inflammation induced by T. gondii, focusing on the role of Th17, Th22 and regulatory T cells (Tregs). C57BL/6-susceptible and BALB/c-resistant mice orally infected with T. gondii exhibited increased frequencies of Th17 and Th22 cells in Lamina Propria and Peyers patches during disease progression. However, whereas C57BL/6 mice exhibited higher frequency of Th17, BALB/c mice showed higher counts of Treg and Th22 cells. The infection also impaired the effector function of Treg cells in susceptible hosts, since Tregs obtained from C57BL/6-infected mice showed a reduced suppressive activity in vitro. The transfer of Foxp3+ cells sorted from non-infected mice, but not from infected mice, increased mice survival. In parallel, we evaluated the role of IL-17 and IL-22 in the disease and we observed that IL-17R-/- and IL-22-/- mice were more susceptible, presented higher parasite burden and intestinal inflammation and lower Treg frequency than C57BL/6. Moreover, IL-17R-/- showed a significant reduction of Th22 cells compared to C57BL/6 mice. Taken together, these findings suggest that IL-17 and IL-22 production are essential for resistance against T. gondii infection, by controlling parasite burden and along with IL-22, Tregs are important for controlling the intestinal inflammation.