bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulatory T cells enhance mast cell production of IL6 via a TGFβ dependent innate mechanism (168.20)
Authors: Ganeshan Kirthana , Bryce Paul 
Published: January 2023

Abstract
Recently, Tregs have been proposed to limit mast cell degranulation upon antigen stimulation. However, mast cells also produce many cytokines that regulate both innate and adaptive immunity. Here we show that Tregs inhibit mast cell (BMMC) degranulation but, surprisingly, promotes IL6 in response to innate (LPS or PGN) and adaptive (IgE) activation. This required cell-cell contact and did not require activation via the TCR. Blockade of OX40/OX40L pathway inhibited the Treg effects on BMMC degranulation but had no effect on IL6 production. Conversely, blockade of surface bound-TGFβ ablated IL6 production, suggesting that Tregs influence mast cell responses via distinct mechanisms. Furthermore, TGFβ was sufficient to promote enhanced IL6 but had no effect on degranulation. In innate immunity, IL6 and Tregs have been suggested to influence neutrophil clearance and resolution of inflammation. In an LPS-driven model of lung injury, Treg depletion elevated lung neutrophilia in response to LPS. Similarly, mast cell deficient mice displayed significantly elevated neutrophilia in the lung that was fully corrected upon reconstitution with wildtype mast cells but not by IL6 deficient mast cells, suggesting a critical role for mast cell derived IL-6 in neutrophil clearance during innate inflammation. Our data suggests that Tregs are important in limiting the severity of the inflammatory response during innate activation and that they may do so by promoting mast cell production of IL-6.
Functional plasticity of regulatory T cells (168.7)
Authors: R. Pillai Meenu , Collison Lauren , Finkelstein David , Rehg Jerold , Boyd Kelli , Workman Andrea , Griffith Thomas , Ferguson Thomas , Vignali Dario 
Published: January 2023

Abstract
Regulatory T cells (Tregs) play a pivotal role in maintaining immune homeostasis, preventing autoimmunity, controlling exaggerated immune responses against infections and suppressing anti-tumor immunity. Tregs utilize multiple mechanisms to mediate their function. However, the number of mechanisms critical to exert maximal suppressive activity is unclear. It is conceivable that suppressive mechanisms could be tightly regulated by cross-regulatory networks. It has been shown that interleukin 10 (IL10) and IL35 have critical role in Treg function. Therefore, we assessed the functional capacity of Tregs lacking the ability to secrete IL10 and IL35. Surprisingly, our study revealed that Tregs lacking both IL10 and IL35 (Ebi3-/-Il10-/- or Il12a-/-Il10-/-) were fully functional and were able to suppress Tconv cells both in vitro and in vivo . Absence of IL10 and IL35 was compensated by an increase in cathepsin E (CTSE), influencing the release of soluble TRAIL and thereby resulting in suppression of target cells in a TRAIL-dependent manner. Inhibiting TRAIL activity disrupted the function of Ebi3-/-Il10-/- Tregs. The loss of suppressive function was maximal in Tregs lacking IL10, IL35 and TRAIL (Ebi3-/-Il10-/-Tnfsf10-/-Tregs). These data suggests the existence of cross-regulatory networks which controls the utilization of suppressive factors, thereby maintaining Treg functional plasticity.
Surfactant Protein-A modulates induction of regulatory T cells in the lung via TGFβ (168.8)
Authors: Mukherjee Sambuddho , Giamberardino C. , Thomas J. , Ledford J. , Evans K. , Pastva A. , Wright Jo Rae 
Published: January 2023

Abstract
TCR signaling plays a critical role in regulatory T cell (Treg) development. However, the mechanism for tissue specific induction of Tregs in the periphery remains unclear. Surfactant protein A (SP-A) is a major immune defense protein in the lung. To determine if SP-A contributes to the normal non-inflammatory status mediated by Tregs in the lung, T cells were activated with various stimuli. Compared to WT mice, on ex vivo culture, T cells from lungs of SP-A deficient mice have impaired expression of Foxp3 and fewer CD25+Foxp3+ Treg phenotype cells. These phenotypic effects could be rescued by the addition of exogenous SP-A. Even as cell cycle progression is blocked, both IL-2 levels as well as active TGFβ levels increase on extended culture. In addition, kinetic suppression assays demonstrate that SP-A enhances the frequency of functional Foxp3+Tregs in responder T cell populations in a TGFβ dependent manner. To induce Tregs in the lung in vivo, we modified the extended LPS model described by d’Alessio et al (1). While the proportion of Tregs increased ≈160% in WT mice ~8d post-exposure, SP-A-/- mice showed a much more modest 50% increase over their near identical baselines. We also observed a strong correlation between FR4 and Foxp3 expression in functional Tregs induced by SP-A. Together, these findings suggest that SP-A exerts long-term effects on T cell immune function by the induction of Tregs during activation. (1) D’Alessio et al J Clin Invest. (2009) 119: 2898
NIK overexpression intrinsically inhibits regulatory T cell function (168.9)
Authors: Polesso Fanny , Murray Susan , Rowe Alexander , Parker David 
Published: January 2023

Abstract
Activation of the non-canonical, or alternative, NF-κB pathway depends on NF-κB-inducing kinase (NIK). We have shown that NIK is intrinsically essential for T cells to cause lethal graft-versus-host disease and to respond to OX40 costimulation. We went on to investigate the effects of NIK overexpression in T cells by crossing inducible NIK transgenic mice to CD4-Cre inducer mice and found that modest NIK overexpression limited to T cells (CD4-NIKtg) caused fatal autoimmunity by 4-weeks of age, resembling the phenotype described in FoxP3-/- and scurfy mice. We hypothesized that NIK overexpression in regulatory T cells (Treg) affects their suppressive phenotype. Here we show that NIKtg Treg cells obtained from healthy bone marrow chimeras fail to suppress WT conventional T cell (Tconv) proliferation in vitro. In addition, NIKtg Tconv obtained from these mice are resistant to suppression by WT Treg cells. Transient NIK overexpression in vitro also represses Treg cell function, and preliminary experiments suggest that NIK overexpression destabilizes the Treg phenotype. Lastly, we investigated the effect of more extreme NIK overexpression using a mutant NIK transgene that is not targeted for degradation (NIKΔTRAF3). Contrary to modest NIK upregulation, excessive NIK accumulation is lethal to T cells. Together, these results show that NIK plays a critical T-cell intrinsic role in both Tconv and Treg, and that its tight regulation is crucial for T cell regulation and survival.
Intracranial administration of human activated NK cells in a xenogeneic model of orthotopic glioblastoma (169.18)
Authors: Ames Erik , Hagino Takeshi , Gorin Frederic , Fragoso Ruben , Murphy William 
Published: January 2023

Abstract
Glioblastoma multiforme (GBM) is a highly invasive end-stage glioma which conveys an extremely poor prognosis. Based on our in vitro data showing very powerful anti-tumor activity of cytokine activated human natural killer cells against the GBM cell line U87MG, we sought to develop a xenograft model of GBM engraftment into NSG mice which would be treated with an intracranial administration of human NK cells. Such NK cell-based therapies allow for autologous NK cells to be utilized, thus minimizing toxicities. While rhIL-2 administered every other day significantly increased NK cell engraftment compared to saline treated controls, a single hydrodynamic injection of human IL15-encoding plasmid produced a far superior engraftment in the brain, spleen, liver, bone marrow and peritoneal fluid 4 days after injection with no toxicities observed. Activated human NK cells were then administered to mice bearing U87MG-luciferase gliomas five days after the orthotopic injection of tumor cells along with IL-2. While NK cell therapy provided a significant tumor volume reduction in the first several weeks after administration, this therapy was unable to protect mice in the long-term from tumor growth and death. Future studies will utilize IL-15 as well as IL-2 in a similar model. These combined data demonstrate the feasibility of NK cell-based therapies for gliomas as well as their potential role as a secondary treatment to target chemotherapy- and irradiation-resistant tumor cells.
DRAK2 blockade leads to transplant tolerance by simultaneous deletion of effector T cells and enrichment of regulatory T cells (169.3)
Authors: Weist Brian , Walsh Craig 
Published: January 2023

Abstract
DRAK2 is a serine/threonine kinase that has previously been shown to negatively regulate activation of T cells through the T cell receptor. Additionally, T cells lacking Drak2 are hypersensitive to low levels of stimulation, but are resistant to T cell mediated autoimmunity. Furthermore, Drak2-/- mice have no defects in viral immunity, making DRAK2 a novel target to replace current non-specific immunosuppressants used following transplantation. We hypothesized that Drak2 deficient T cells die after activation, and tested the ability of these T cells to respond to allogeneic stimulation. Using in vitro mixed lymphocyte reactions, Drak2-/- CD8+ T cells exhibited defects in accumulation after 5 days of allostimulation compared to wildtype T cells in vitro. Additionally, in vivo, allogeneic tumors grew uncontrolled by Drak2-/- T cells, and allogeneic skin graft rejection was significantly delayed. Overexpression of anti-apoptotic Bcl-xL in Drak2-/- T cells restored rejection of allogeneic tumors. Additionally, Drak2-/- mice had increased proportions of Tregs, and depletion of Tregs in a skin transplant model significantly enhanced Drak2-/- alloresponses. As a consequence of deletional tolerance, allogeneic memory was drastically reduced post transplant in Drak2-/- mice. Overall, these results demonstrate that DRAK2 plays a significant role in allograft responsiveness and highlight this kinase as a potential pharmacologic target in efforts to block allograft rejection.
Altered T cell profiles in uterine draining lymph nodes of mice with preterm labor (169.31)
Authors: Nijagal Amar , Wegorzewska Marta , Le Tom , Tucker Andrew , Tang Qizhi , MacKenzie Tippi 
Published: January 2023

Abstract
Background: Preterm labor (PTL) is a devastating consequence of fetal interventions such as in utero hematopoietic cell transplantation (IUHCTx). We previously found that PTL after allogeneic IUHCTx is decreased in mice lacking T cells. We hypothesized that the T cell profile in the uterine draining lymph nodes (uLN) would be altered in mothers with PTL. Methods: Mothers carrying semi-allogeneic fetuses underwent IUHCTx at E14.5. At E18.5, we quantified maternal CD4+, CD8+, and CD4+Foxp3+ T cells and measured the production of IL2, IL4, IFN gamma, and IL17 in the uLN, spleen, or non-draining lymph nodes (ndLN). Results: We found equivalent numbers of CD4+ and CD8+ T cells when comparing mothers with and without PTL. We observed a significant increase in the proportion of CD4+Foxp3+ T cells only in the uLN of mothers who experienced complete fetal loss. We also observed equivalent IL2, IFNγ, and IL17 production between all groups. IL4 production by CD4+Foxp3+ T cells was, however, significantly elevated in the uLN of mothers who aborted their entire litter. Conclusions: PTL after fetal intervention leads to expansion of the CD4+Foxp3+ T cell pool in the uLN. The production of IL4 by CD4+Foxp3+ T cells in the uLN suggests that the conversion of these cells to Th2 T effectors may be one potential mechanism by which maternal T cells participate in PTL. Our results support the role of maternal T cells in the pathogenesis of PTL.
IL6 is necessary for the progression of experimental autoimmune myocarditis to dilated cardiomyopathy (171.11)
Authors: Legault Jillian , Baldeviano G. , Barin Jobert , Wu Lei , Ong SuFey , Talor Monica , Cihakova Daniela , Rose Noel 
Published: January 2023

Abstract
Previous findings in our lab have showed that IL17A deficient animals are protected from the progression of experimental autoimmune myocarditis (EAM) to dilated cardiomyopathy (DCM). These findings showed an increase of systemic IL6 in the WT animals that progressed to heart failure, whereas the protected IL17A deficient animals had lower IL6 levels. This was the only cytokine shown to differ consistently between the two groups at both day 14 and 21. We sought to address the question of whether systemic IL6 levels can mediate disease and is therefore critical for DCM development. To investigate the IL17A requirement for DCM development through its induction of IL6, we used two experimental approaches. First, we over-expressed IL6 in WT animals with EAM through hydrodynamic gene delivery on day -1 prior EAM induction. WT mice, which over-expressed an IL6 insert, showed worsening of heart function by echo on day 54 compared to controls with empty plasmid. Second, we blocked IL6R signaling using an anti-IL6R monoclonal antibody (mAb) in WT BALB/c mice with EAM. In mice administered the anti-IL6R mAb on days 6 and 13 of EAM, the mice were protected from heart failure and DCM development by day 60 of disease compared to animals receiving isotype control antibodies. Our data suggest that IL6 early during EAM is necessary for the development of DCM.
Effects of apoptotic cell accumulation caused by Mer deficiency on germinal center B cells and follicular helper T cells (171.12)
Authors: Khan Tahsin , Wong Eric , Rahman Ziaur 
Published: January 2023

Abstract
Mer (MerTK) is a member of the Tyro-3/Axl/Mer (TAM) subfamily receptor tyrosine kinases which facilitates phagocyte clearance of apoptotic cells (ACs). We previously showed that Mer expression in germinal centers (GCs) occurs predominantly on tingible body macrophages (TBMϕs). Furthermore, deficiency in Mer (Mer-/-) results in accumulation of ACs in GCs leading to augmented antibody-forming cell (AFC), GC and Th1-skewed IgG2 Ab responses. Here we show that elevated AFC, GC and IgG2 Ab responses in Mer-/- mice were due to increased proliferation of B cells and higher number of TFH cells in Mer-/- GCs. AC accumulation in Mer-/- GCs was also associated with elevated long-lived primary and secondary AFC, GC B cell, TFH cell and IgG2 Ab responses compared to controls. Interestingly, AC accumulation in Mer-/- GCs was not due to increased B cell apoptosis, rather due to a defect in AC clearance. Finally, by evaluating GC TBMϕ expression of several other bridging molecules and receptors (i.e., Axl, Tyro-3, Mfge-8 and Tim-4) involved in AC clearance, we ruled out the contribution of the potential alteration in the expression of these molecules/receptors to AC accumulation in Mer-/- GCs. These data indicate that accumulation of ACs in Mer-/- GCs is primarily due to Mer deficiency. Together these results highlight the important role of AC clearance by Mer in regulating GC B cell and TFH cell responses and in maintaining peripheral B cell tolerance.
Pain and inflammation coincide in a collagen-induced arthritis model in rats (171.17)
Authors: McCarthy Richard , Goess Christian , Rundell Lian , Cuff Carolyn , Prisca Honore , Andrew Long 
Published: January 2023

Abstract
Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation, swelling and destruction. In patients diagnosed with RA, these symptoms manifest as pain and lead to fatigue, physical impairment and loss of function. This can be modeled pre-clinically using collagen induced arthritis (rat CIA). Historically, increased swelling of the hind paws measured by plethysmography, and inflammation measured by histology in the ankle joints of arthritic rats have been used to evaluate the effects of potential anti-inflammatory therapies. In the present study, we set out to understand the relationship between joint inflammation and pain. To evaluate knee inflammation, we employed a technique that involves lavaging the knee joint to determine the characteristics of the inflammation (cells and cytokines). Knees of arthritic animals had increased cellularity and pro-inflammatory cytokines including IL-1b and IL-6, as well as increases in the neutrophil chemokine KC. To evaluate pain, we used Von Frey monofilaments to elicit mechanical allodynia as measured by paw withdrawal. We initially observed increased paw withdrawal activity on day 11, with maximal pain responses by day 15 that were maintained through day 18. These findings indicate that mechanisms of pain and inflammation are coordinate in the rat CIA model. Measurement of pain in preclinical models of RA will aid in the development of future effective therapies.
Potential roles for soluble MD-1 in disease progression of autoimmune prone MRLlpr/lpr mice (171.2)
Authors: Nagai Yoshinori , Yanagibashi Tsutomu , Watanabe Yasuharu , Ikutani Masashi , Kariyone Ai , Tsuneyama Koichi , Hirai Yoshikatsu , Takatsu Kiyoshi 
Published: January 2023

Abstract
MD-1 is a secreted protein that forms a complex with radioprotective 105 (RP105) on B cells, macrophages and dendritic cells. This complex plays a crucial role in lipopolysaccharide (LPS) recognition by B cells. Disease progression is known to improve in RP105-deficient lupus-prone MRLlpr/lpr mice. Furthermore, a soluble form of the homologous MD-2 protein is present in the plasma of septic patients and can opsonize gram-negative bacteria in cooperation with Toll-like receptor 4. We have now established a flow cytometry-based assay to detect endogenous soluble form of murine MD-1 (sMD-1) and explored potential roles in autoimmunity. The assay was quantitative and validated with sera from MD-1-deficient mice. Interestingly, heat-inactivated murine serum diminished the ability of sMD-1 to bind RP105. The sMD-1 was secreted by bone marrow-derived macrophages from C57BL/6 mice. Autoimmune prone MRLlpr/lpr mice had higher levels of serum sMD-1 than control MRL+/+ mice, and levels markedly increased with disease progression. Expression of MD-1 but not MD-2 mRNA increased with age in the liver and kidney of MRLlpr/lpr mice. Finally, immunohistochemical analyses revealed that MD-1 was present in infiltrated macrophages within perivascular lesions of the MRLlpr/lpr kidney. This correlation suggests that sMD-1 may contribute to pathogenesis in this autoimmune disease model mouse. Also, sMD-1 may be feasible to monitor autoimmune disease severity.
Severity of autoimmune myocarditis is influenced by Connexin43 expression (171.23)
Authors: Glass Aaron , Coombs Wanda , Taffet Steven 
Published: January 2023

Abstract
Myocarditis, or inflammation of the heart muscle, is associated with severe morbidity and mortality, even in young, otherwise healthy individuals. The disease is initiated by exposure to viruses, parasites, and toxins, but can develop into a chronic autoimmune disease which progresses to severe fibrosis and dilated cardiomyopathy. Work in our lab using experimental autoimmune myocarditis (EAM) as a model, has demonstrated alterations in the sub-cellular localization of the cardiac gap junction protein connexin43 (Cx43) in heart tissue adjacent to myocarditis lesions, a potentially arrythmogenic effect. In the present study, we found the converse to be true; a reduction in Cx43 expression altered the course of EAM, resulting in a more pronounced disease. To generate animals with reduced Cx43, we backcrossed CX43+/- mice on the EAM-resistant C57BL/6 background to the EAM-susceptible BALB/c background. After 8 generations, we initiated EAM by two doses of α myosin heavy chain antigenic peptide at days 0 and 7. Hearts were analyzed 21 days after EAM induction for both the area and intensity of immune infiltrate. We determined that mice heterozygous for Cx43 develop more severe disease than wild type littermates. Closer analysis of infiltrating immune cells by immunofluorescence microscopy revealed differences in myeloperoxidase positive and CD3+ cells, with Cx43 heterozygotes having more of both. These results suggest that Cx43 can alter the course of EAM.
Complement component C1q regulates macrophage expression of Mer tyrosine kinase to promote clearance of apoptotic cells (171.31)
Authors: Galvan Manuel , Foreman Deborah , Bohlson Suzanne 
Published: January 2023

Abstract
Failure to efficiently clear apoptotic cells is linked to defects in development and autoimmunity. Complement component C1q is required for efficient clearance of apoptotic cells, and C1q deficiency is the strongest known susceptibility factor for autoimmunity associated with lupus. Despite the importance of C1q in apoptotic cell clearance, the mechanism by which C1q enhances apoptotic cell clearance is poorly understood. Here we describe a novel C1q-dependent engulfment mechanism for apoptotic cells. We found that macrophage activation with C1q resulted in cycloheximide-sensitive enhanced engulfment, indicating a requirement for de novo protein synthesis. To investigate the cycloheximide-sensitive pathway, C1q-elicited macrophage transcripts were identified by microarray. C1q triggered the expression of Mer tyrosine kinase and Gas 6: a receptor-ligand pair that mediates clearance of apoptotic cells. This novel pathway is specific to C1q since MBL, a related collectin, failed to upregulate Mer expression and function. Soluble Mer-Fc fusion protein inhibited C1q-dependent engulfment of apoptotic cells. In addition, Mer-/- macrophages failed to respond to C1q with enhanced engulfment of apoptotic cells, indicating a requirement for Mer. Our results suggest that C1q elicits a macrophage phenotype specifically tailored for apoptotic cell clearance, and these data are consistent with the established requirement for C1q in prevention of autoimmunity.
S100A4 is expressed in myeloid cells invading inflamed pancreatic islets and supports development of Type 1 diabetes (171.33)
Authors: Kendall Peggy , Pedchenko Tetyana , Case James , Sullivan Allison , Kendall Peggy 
Published: January 2023

Abstract
Type 1 diabetes (T1D) results from adaptive autoimmune destruction of insulin-producing beta cells in pancreatic islets. Macrophages and dendritic cells (DCs) have also been implicated in the disease process, although their roles are less well-studied than those of T cells. S100A4 is a small calcium-activated molecule that contributes to cancer metastases and fibrosis, and has recently been linked to autoimmunity. We have discovered S100A4 among inflammatory infiltrates in pancreatic islets in a T1D model. Cells expressing S100A4 bear surface markers associated with antigen-presentation, such as MHCII and CD86. These cells include CD11c+ DCs, CD11b+ macrophages, and CD11b+/CD11c+ myeloid populations. Neither plasmacytoid DCs (PDCA1+/Ly6C+/B220+) nor lymphoid DCs (CD8+) express S100A4. S100A4-deficiency was engineered by GFP-targeting and introgressed onto the nonobese diabetic (NOD) mouse model of T1D for &gt;10 generations. S100A4-/-/NOD mice are protected from the development of T1D, with a concomitant reduction in insulitis. However, GFP-expression in S100A4-deficient cells indicates that these cell populations remain in the inflamed islets. When compared to S100A4-sufficient counterparts, S100A4-deficient bone marrow-derived DCs have decreased ability to upregulate CD86, or to present antigen and activate T cells in vitro. Thus, S100A4 may contribute to the development of T1D by supporting myeloid cell antigen-presentation to autoreactive T cells.