bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aging alters murine peritoneal macrophages in a sex-dimorphic fashion
Authors: Lu Ryan , Wang Eric , Kim Minhoo , Sampatkumar Nirmal K , Benayoun Bérénice A 
Published: January 2023

Abstract
Aging is accompanied by general immune dysfunction, which is hypothesized to underlie the pathogenesis of many age-related diseases. In addition, there is accumulating evidence that aging is highly sex-dimorphic. However, the interactions of age and sex on the genomic and functional landscape of immune cells remain largely unexplored. To address this question, we have interrogated cells of the peritoneal cavity, an easily accessible immune niche, during aging in both sexes of C57BL/6 mice using single cell RNA-seq and flow cytometry. Interestingly, we found that macrophages were the most affected by age and sex among peritoneal immune cells, and that their frequency significantly dropped with aging. Macrophages are important for the initiating and resolving of inflammation, and dysfunction can contribute to inflammaging. Thus, we decided to further investigate the potentially sex-dimorphic impact of aging on the genomic landscape and function of peritoneal macrophages. We generated bulk RNA-seq data from purified peritoneal macrophages and identified genes modulated with aging as a function of sex. Complementing this ‘omic’ dataset, we performed an array of functional assays using purified peritoneal macrophages. We observed sex-dependent functional alterations, such as female-specific decrease in phagocytic ability. From our RNA-seq analysis, we identified potential regulators of phagocytosis that are significantly downregulated with age only in females. We are currently validating whether the potential regulators may indeed drive the observed female-specific decrease in phagocytic capabilities. Ultimately, this project will help delineate sex dimorphic mechanisms modulating immune aging.
This work was supported by a Diana Jacobs Kalman/AFAR Scholarships for Research in the Biology of Aging and NIA T32 AG052374 (to R.J.L.), GCRLE-2020 post-doctoral fellowship from the Global Consortium for Reproductive Longevity and Equality at the Buck Institute, made possible by the Bia-Echo Foundation, (to M.K.), and NIA R00 AG049934, Pew Biomedical Scholar award #00034120, an innovator grant from the Rose Hills foundation, and the Kathleen Gilmore Biology of Aging research award (to B.A.B). This work was also partially supported by NCI Cancer Center Support Grant P30 CA014089 through the use of shared resources.
Do adipose macrophages remember obesity? Innate immune memory in weight cycling
Authors: Caslin Heather L , Cottam Matthew , Winn Nathan , Hasty Alyssa 
Published: January 2023

Abstract
Weight loss improves obesity-associated metabolic disease; however, it is difficult to accomplish and even more difficult to maintain. Thus, many individuals regain weight within a few years. Unfortunately, weight cycling worsens the risk of developing diabetes beyond obesity itself. Adipose immune cells contribute to inflammation and diabetes risk with obesity, but less is known about adipose immune cells in weight loss and weight cycling.
New data from a mouse model in our lab suggest that weight loss rescues glucose tolerance, but the immune landscape is not restored to a lean state. Adipose memory T cells, lipid handling macrophages, and exhausted T cells remain elevated with weight loss and further increase with weight regain suggesting that immune cells remember the state of obesity. Because immune memory can occur in the myeloid lineage, this project aims to determine if weight cycling induces innate memory in adipose macrophages.
We find that adipose macrophages retain their obese phenotype; with increased glycolysis and cytokine production in response to LPS. Interestingly, adipose macrophages from weight cycled mice are even more metabolically active and secrete more basal TNF. We can replicate this phenotype in a cell culture model of innate memory with palmitate or adipose conditioned media, which may be a useful model to determine mechanisms for metabolic memory. Current work is investigating metabolic and epigenetic regulation of both the in vitro and in vivo systems using ATAC-sequencing and metabolic flux analysis. Future studies will explore the contribution of adipose macrophage memory to weight cycling-accelerated metabolic disease and aim to uncover new therapeutic targets to improve metabolic dysfunction.
This work was funded by a Veterans Affairs Merit Award (5I01BX002195) to AH and a T32 Training Grant (DK07563) and AHA Postdoctoral Fellowship (20POST35120547) to HC.
Choline metabolism promotes M2 macrophage polarization in intestinal infection with helminth Heligmosomoides polygyrus
Authors: Kim Sang Yong , Ghorbani Peyman , Woo Daniel , Fullerton Morgan D , Nair Meera G 
Published: January 2023

Abstract
Choline is an essential nutrient functioning as a precursor for membrane phospholipid. In previous studies, LPS polarization augmented both the expression of the choline transporter CTL1 and choline uptake, while specific inhibition of choline transport led to increased TNFα and IL-6. However, whether choline metabolism regulates M2 macrophage polarization or Th2 cytokine inflammation in vivo is unclear. In vitro, CTL1 and phospholipid synthesis was induced in IL-4 polarized M2 macrophages. To determine the function of choline metabolism in M2 polarization in vivo, mice were infected with Heligmosomoides polygyrus, intraperitoneally injected with choline kinase α inhibitor, RSM-932A or vehicle, and sacrificed at day 17 post-infection. RSM-932A treatment impaired weight gain and peritoneal exudate cell numbers in both naïve and infected mice. Within the peritoneal cavity of infected mice, macrophages and B-1 lymphocytes were depleted by RSM-932A treatment, while monocytes and neutrophils were increased. Flow cytometric and intestinal immunofluorescence staining revealed that RSM-932A treatment prevented M2 macrophage polarization in H.polygyrus-infected mice with a significant reduction in expression of PD-L2 and CD206, and conversely increased expression of CD86 and PD-L1. Additionally, RELMα protein in the serum and peritoneal fluid was downregulated by RSM-932A treatment. The impaired M2 polarization was associated with some loss in optimal immunity to H.polygyrus with increased parasite egg burden but no differences in intestinal worm count. This study indicates that choline metabolism is required for M2 macrophage polarization and an optimal immune response against intestinal helminth infection.
NK cell-derived IL-10 enhances Plasmodium-specific CD4+ Tfh differentiation and IL-27 production in mice
Authors: Burrack Kristina S , Harris Morgan , Dileepan Thamotharampillai , Jenkins Marc K , Frosch Anne 
Published: January 2023

Abstract
Malaria, which results from infection with Plasmodium parasites, remains a major public health problem with over 200 million cases and nearly 500,000 deaths annually. Although long-lived, sterilizing immunity does not develop in humans following repeated exposure to Plasmodium parasites, protection against symptomatic disease correlates with the acquisition of humoral immunity. Despite the established role antibodies play in protection to malaria disease, excessive inflammation is thought to contribute to the ineffective immune response to Plasmodium infection. Plasmodium berghei ANKA (PbA) infection results in a fatal severe malaria disease in mice. We previously showed that treatment of mice with IL-15 complex (IL-15C; IL-15 bound to an IL-15Rα-Fc fusion protein) induces IL-10 expression in NK cells, which protects mice from PbA-induced death by dampening the fatal inflammatory response. Interestingly, IL-15C treatment promotes Tfh differentiation at 7 days post-PbA infection (dpi), and genetic deletion of NK cell-derived IL-10 or antibody blockade of IL-10R prevents IL-15C-induced Tfh differentiation. Additionally, IL-15C treatment enhances CD4 T cell-derived IL-27p28 production at 7 dpi and results in increased anti-PbA IgG antibody levels at 42 dpi. These data suggest that IL-15C treatment, via its induction of IL-10 from NK cells, modulates the inflammatory milieu to promote Tfh differentiation, IL-27 production, and PbA-specific antibody generation. These findings will facilitate improved control of malaria infection and protection from disease by informing therapeutic strategies and vaccine design.
Supported by grants from NIH (K22 AI143969-01A1, K08 AI141761-01)
Cell-specific roles for miR-155 during neuroinflammation
Authors: Thompson Jacob W , Huffaker Thomas , Hu Ruozhen , O’Connell Ryan M 
Published: January 2023

Abstract
The pro-inflammatory microRNA-155 (miR-155) is highly expressed in the serum and CNS lesions of patients with multiple sclerosis (MS). The whole-body deletion of miR-155 in mice confers resistance to a mouse model of MS, EAE, by reducing the encephalogenic potential of CNS-infiltrating Th17 T cells. Here we utilize single-cell RNA sequencing and cell-specific conditional miR-155 knockouts to determine the importance of miR-155 expression in distinct cell populations. Time course single-cell sequencing revealed reductions in T cells, macrophages, and dendritic cells in whole-body miR-155 knockout mice compared with wild-type controls at day 21. Deletion of miR-155 in T cells, driven by CD4 cre, reduced disease severity similar to whole-body miR-155 knockouts. CD11c cre-driven deletion of miR-155 in dendritic cells also significantly reduced EAE disease score, with both T cell and dendritic cell-specific knockouts showing a reduction in Th17 T cell infiltration into the CNS. Although miR-155 is highly expressed in macrophages during EAE, deletion miR-155 by LysM cre in did not affect disease severity.
Classification of novel conditional POSH knockout murine models
Authors: Guldenpfennig Caitlyn E , Guan Yue , Teixeiro Emma , Daniels Mark 
Published: January 2023

Abstract
Plenty of SH3 Domains (POSH) is a critical scaffold protein in neuronal and lymphocyte signaling involved in survival, development, and effector function. Our lab has shown a sharp decline in survival and activation in T cells and decreased survival of lymphocyte leukemias upon inhibition of POSH function in vitro. However, the in vivo function of POSH in lymphocyte survival and function has not been examined. We hypothesized that POSH deletion in vivo impacts murine lymphocyte development and effector function. We used the Cre/Lox system to conditionally knockout POSH in T cells (CD4-Cre) or B cells (CD19-Cre) in C57B6 mice. POSH deletion in lymphocytes was examined through Western Blot and RNA extraction, and the effect of the loss of POSH on development and function was assessed via flow cytometry. We found that CD4-Cre T cells showed a developmental block at the maturation stage in the thymus. Upon stimulation, CD4-Cre T cells showed reduced proliferation and cytokine production. Additionally, CD19-Cre B cells showed developmental defects, including more BP-1 expression and a higher frequency of Pre-B early cells. This study demonstrated that the in vivo deletion of POSH impacts development, proliferation, and effector function of lymphocytes. These data corroborate previous in vitro results with our inhibitor. Thus, these novel murine models will enable us to assess the role of POSH in developing a fully functional immune compartment and its role in supporting leukemia oncogenesis and survival.
Supported by grants from NIH-MBARC, NIBIB (EB026560), NIGMS (GM135744), DoD (RT160149)
Mediator complex maintains peripheral T cell tolerance through enforcement of the quiescence module
Authors: Chaudhuri Shuvam Mohan , Zhang Yana , Weinberg Samuel E , Fang Deyu 
Published: January 2023

Abstract
T cell tolerance has traditionally been thought to be maintained at stages after T cell receptor mediated activation either through anergy, exhaustion, contraction or T Regulatory cell mediated dominant suppression. Prior to these mechanisms, however, T cell quiescence is the main factor maintaining T cell tolerance. We have identified Mediator Complex Subunit 1 (Med1), as a novel factor responsible for enforcing T cell quiescence. Mice with T cell specific deletion of Med1 display increased levels of T cell activation despite having a normally functional T Regulatory cell compartment. Med1-deficient T cells were more responsive to T cell receptor mediated activation. Bone marrow chimeras revealed Med1 controls T cell quiescence in a cell intrinsic manner. Bulk and single cell transcriptome sequencing revealed Med1’s transcriptional control over key quiescence factors. By analyzing previously published chromatin immunoprecipitation sequencing we found Med1 controlled a transcription factor network rather than direct quiescence molecules. Med1 is a novel factor responsible for actively enforcing the transcriptional network maintaining T cell quiescence.
Supported by T32DK007169 R01CA257520 R01CA232347
Overcoming inhibitory constraints to TCR signaling by targeting the pH-sensitive phosphatase suppressor of T-cell receptor signaling 1 (STS1)
Authors: Tsai Yuan-Li , Badia Marcel Arias , Kadlecek Theresa A , Shah Neel H , Fong Lawrence , Weiss Arthur 
Published: January 2023

Abstract
T cells are critically important for adaptive immune responses. Therefore, maintaining their proper homeostasis an d controlling the magnitude of their responses is critical. To control T cell responses, T cell activity is negatively regulated by inhibitory molecules. The Cbl protein family are ubiquitin E3 ligases that suppress TCR signaling by mediating the degradation of TCR signaling molecules. However, studies and our results suggest that Cbl proteins down-regulate phospho-proteins without modulating the total level of target proteins, but the mechanisms are unclear. Here, we show that Cbl-b serves as an adapter to recruit STS1, an unconventional tyrosine phosphatase, to dephosphorylate target proteins and inhibit TCR signaling. STS1 binds to a Cbl-b PPVPP motif via its SH3 domain, and the interaction requires Cbl-b phosphorylation by ZAP70. Elimination of the PPVPP motif compromises Cbl-b suppressive activity, and deletion of STS1 leads to T cell hyper responsiveness to TCR activation which phenocopies Cbl-b deficiency. Furthermore, STS1 uniquely relies on histidine to catalyze dephosphorylation, making it hyperactive in acidic environment. As a result, STS1 and Cbl-b deficient T cells remain hyper responsive and insensitive to low pH whereas WT cells are largely suppressed. Animals with STS1 or Cbl-b deletion show delayed tumor growth and improved survival. Together, these results demonstrate Cbl-b partners with STS1 whose activity is responsive to pH changes to modulate TCR signaling. Moreover, they suggest the pH sensitivity of STS1 is uniquely suited to suppress T cell responses that occur in vivo, such those that occur within inflammatory settings and within tumors, where lower pH conditions may be encountered.
Supported by fellowship from Cancer Research Institute (A133417)
Absence of the fatty acid binding protein5 (FABP5) inhibits the establishment of resident memory T cells after a secondary Listeria monocytogenes infection
Authors: Aviszus Katja , Giron Aaron , El Kharbili DiLisio Manale , Zhao Xiaoyun , Gally Fabienne 
Published: January 2023

Abstract
Fatty acid binding protein 5 (FABP5) is a member of the family of fatty acid binding proteins involved in fatty acid uptake, transport, and metabolism. FABP5 is ubiquitously expressed, including in T cells. During the course of an immune reaction, T cells undergo multiple changes to their metabolism. Once naïve T cells are activated, expansion is triggered, and cells differentiate to become effector cells accompanied by a metabolic change from fatty acid oxidation to glycolysis. Once the pathogen is eliminated, effector cells differentiate into memory cells, with central memory (TCM) and effector memory (TEM) cells surveying the circulation and resident memory (TRM) cells establishing a tissue memory pool that can quickly react to localized reinfection. These TRM cells are thought to rely on lipid uptake and fatty acid oxidation for survival. We wanted to investigate the effect of FABP5 on the development of CD8+ TRM cells in the context of a Listeria monocytogenes (Lm) infection. We had previously shown that the lack of FABP5 leads to a resistance to Lm in mice after a single infection, while the overexpression of FABP5 showed increased mortality and bacterial burden. Here, we used WT and FABP5−/− mice in an infection model with Lm-Ova to analyze the innate and antigen-specific adaptive immune responses. To this end, WT and FABP5−/− mice were infected i.v. with Lm-Ova and their immune responses analyzed at various days after. We show that while the primary immune response is improved in FABP5−/−, there was a profound negative effect on the secondary response. This was based on a severe reduction of Ova-specific TRM in the liver while TCM and TEM populations were unaffected. Flow analyses and functional assays taken throughout will be presented.
Supported by NHlDI 1R01HL141264
Supported by NHlDI 1R01HL141264
TCR-enriched microvesicles provide antigen-specific help for class-switched antibody production
Authors: Li Fenglei , Choudhuri Kaushik 
Published: January 2023

Abstract
Extracellular vesicles have shown essential roles in various biological processes, mainly through mediating cell-cell communications by its surface and internal cargo. Recently it was found that activated T cells release TCR enriched microvesicles (Tc-MV) from immunological synapse, but the function of Tc-MV is still a mystery. By analyzing proteomics and miRNA profiles of Tc-MV derived from mouse OT-II CD4 T cells (OVA323–339 specific), we found Tc-MV are enriched with proteins related to T cell helper function, including TCRs, CD40L, CD28, ICOS, OX40 and LFA-1, and also contained B cell function involved miRNAs, such as miR-21a-5p, miR-28a-3p, miR-155-5p and miR-210-3p. Accordantly, by in vitro coculture, OT-II Tc-MV could promote NP-specific B cells to secret IgG when cognate antigen NP-OVA was present, similarly Tc-MV from SMARTA T cell (LCMV GP61–80 specific) could promote B cells with antigen NP-GFP-GP61–80, but switching either the MV or the antigens in these two systems dampened the antibody production, suggesting Tc-MV help B cells in an antigen specific manner. The helper function of the Tc-MV was also confirmed in vivo by serum antibody production of Rag1−/− mice transferred with Tc-MV and B cells and followed by immunization, importantly the endogenous Tc-MV were found in the serum of the WT mice post-immunization, demonstrating a fundamental role of Tc-MV in the physiological condition. In conclusion, our findings revealed a critical role of Tc-MV in promoting antigen specific antibody production of B cells, which can be exploited for vaccine design.
Supported by University of Michigan Startup Funds and NIH: R01AI134999.
Age-dependent changes in the regulatory program of CD8+ Regulatory T cells (CD8+ Tregs)
Authors: Srinivasan Saranya , Chaoyu Ma , Mishra Shruti , Wang Liwen , Fan Kenneth , Zhang Nu 
Published: January 2023

Abstract
Regulatory T cells (Tregs) help maintain the immune homeostasis. Any defect in the Tregs causes dysregulated immune responses that leads to risk of infection, autoimmunity, and cancer. Increased morbidity in the elderly patients is due to age-related changes in the immune system called immune aging. Despite several age-related studies in immune cells, immune aging in CD8+ Tregs are poorly characterized. With the growing number of evidence for the presence of various CD8+ Treg subset, our group has recently discovered that mice with knock out of specific CD8+ Treg subset characterized as CD8+ CD122+ Helios+ developed lethal autoimmune phenotype. To our surprise, the autoimmune phenotype is CD4+ Treg independent which underscores the important role of CD8+ CD122+ Helios+ Tregs in autoimmunity. This study investigated the age-associated changes in the CD8+ CD122+ Helios+ Tregs. We measured the quantitative and phenotypic changes of CD8+ Tregs at homeostasis in young (2 months) and older (12–24 months) mice. Our results demonstrate that at homeostasis, frequency of CD8+ Tregs in total lymphocytes is higher in older mice. Of note, older CD8+ Tregs upregulated the expression of Natural Killer group 2-member protein like NKG2A and NKG2D. We used acute infection model to test the age-related effect of infection/inflammation in the CD8+ Treg. We found that Treg numbers further expanded in older mice during acute infection and functionally superior to young mice. In addition, older CD8+ Tregs exhibited altered metabolic profile which might contribute to the immune senescence. In summary our findings support that CD8+ Treg may contribute to the weakened immune response in the elders.
T cell fate and central tolerance: using iTregs to elucidate the persistence of thymic development on a T cell’s behavior
Authors: White Jason , Ishihara Kazumi , Sakaguchi Shimon 
Published: January 2023

Abstract
Evidence continues to mount in the T cell field that a cell’s affinity for self-peptide MHC predisposes the T cell to particular outcomes when challenged with certain stimuli (whether that stimuli be self or foreign antigen). This aspect of the system suggests that there is, perhaps, some amount of thymic “programming” that occurs during the development of the T cell which serves as another tolerance mechanism; in this case, bridging the central/peripheral tolerance paradigm. In this project, using an induced Treg model and controlling potential disparities in signalling and TCR strength whenever possible, we attempt to determine to what extent the fate of a naive T cell can remain plastic, and to what extent it still reflects the circumstances of its development.
Glucocorticoid signaling and regulatory T cell collaborate to maintain the hair follicle stem cell niche
Authors: Zheng Ye , Liu Zhi , Hu Xianting , Liang Yuqiong , Yu Jingting , Shokhirev Maxim N 
Published: January 2023

Abstract
The maintenance of tissue homeostasis in steady state or under stress is dependent on the proper communication between the stem cells and the supporting cells in their microenvironment or “niche”. In addition to promoting immune tolerance, regulatory T cells (Tregs) have recently emerged as a critical component of the stem cell niche in the hair follicle (HF), injured muscle, bone marrow, and small intestine to support stem cell differentiation or maintain their quiescence. How Treg cells sense the dynamic signals in the niche environment and communicate with stem cells during tissue regeneration is largely unknown. Here, by using HF as a model, we uncover a hitherto unrecognized function of steroid hormone glucocorticoid that instructs skin-resident Treg cells through glucocorticoid receptor (GR) to facilitate hair follicle stem cell (HFSC) activation and HF regeneration. Ablation of GR signaling in Tregs blocked depilation-induced hair regeneration and natural hair growth without affecting Treg’s immune suppressive function. Mechanistic study revealed that GR signaling induces skin-resident Tregs to produce TGF-b3, which directly activates Smad2/3 in HFSCs and facilitates HFSC activation and proliferation. Our study identifies a novel crosstalk between skin-resident Tregs and HFSCs mediated by the GR/TGF-b3 axis, highlighting a new avenue to manipulate Tregs to support tissue regeneration.
Supported by NIH R01-AI107027 NIH R01-AI1511123 NIH R21-AI154919 NIH S10-OD023689