bluuebunny/crossref_metadata_2025_split huggingface dataset:
FVIII-Fixed Splenocytes Induce Tolerance in Hemophilic Mice (65.4)
Authors: Su Yan , Miller Stephen , Scott David 
Published: January 2023

Abstract
Monogenic diseases, such as hemophilia A, can be treated with protein therapeutics, such as recombinant factor VIII. A problem with this therapy is the patient’s immune response to the human protein to which they are not tolerant. This is manifested by antibody formation in up to 30% of patients. Called “inhibitors”, such antibodies block the efficacy of therapeutic FVIII. Administration of human FVIII to hemophilia A mice (Exon 16 deleted FVIII-/- [E16]) is a small animal model for the immune response and tolerance to FVIII. These mice manifest a robust, T-cell dependent, antibody response to exogenous FVIII treatment even when given via tolerogenic routes. Tolerance to FVIII requires multiple high doses of FVIII and is costly. Hence, therapeutics for inducing tolerance to these inhibitory antibodies are desired. Ethylene carbodiimide (ECDI) cross-linking of antigens to splenocytes has been utilized to generate tolerance in multiple models. We show that ECDI-fixed splenocytes specifically suppress anti-FVIII responses in the E16 mouse hemophilia model. We coupled a FVIII immunodominant peptide (C22310-2330) and transferred coupled splenocytes into FVIII deficient Balb/c E16 mice. Upon challenge with C22310-2330 and OVA323-339 peptides, these recipients exhibited specifically reduced T-cell responses to FVIII. This strategy has potential as a novel therapeutic for treating hemophilia patients with inhibitors
Drak2 contributes to type 1 diabetes by mediating effects on effector and regulatory T cells (65.7)
Authors: Creasy Blaine , McGargill Maureen 
Published: January 2023

Abstract
Drak2 is a serine/threonine kinase that is primarily expressed in B and T lymphocytes. Previously, we showed Drak2 deficient mice are resistant to autoimmune disease in models of type 1 diabetes and multiple sclerosis. Our studies suggest the resistance to disease is due to a defect in the survival of autoreactive T cells. However, Mao et al. demonstrated expression of Drak2 in pancreatic β-islet cells and suggested that Drak2 is involved in cytokine induced apoptosis of β-islet cells. Thus, we investigated whether the resistance to diabetes is T cell intrinsic or due to the role of Drak2 in β-islet cell apoptosis. Adoptive transfer experiments revealed the resistance to diabetes is T cell intrinsic. Upon further investigation we found that not only do Drak2-/- T effector cells have an inherent survival defect, but mice lacking Drak2 have an increased proportion of T regulatory cells. In addition, Drak2-/- T regulatory cells were more effective at suppressing the proliferation of WT or Drak2-/- cells in vitro and in vivo. We are currently investigating the possible suppressive mechanisms responsible for these results. Most interestingly, Drak2-/- Treg cells were able to prevent WT pathogenic T cells from inducing diabetes in adoptive transfer models. These data reveal the resistance to diabetes in Drak2-/- mice is T cell intrinsic and occurs due to a slight shift in the ratio of pathogenic T cells to Tregs along with enhanced Treg suppressive activity in the absence of Drak2.
Calpastatin is a crucial regulator of macrophage activation that limits in vivo inflammation (66.1)
Authors: Hoffmann Peter , Rose Aaron , Hoffmann FuKun , Norton Robert , Huang Zhi 
Published: January 2023

Abstract
Calpain enzymes regulate cellular function through the proteolytic modulation of structural and signaling proteins. Calpain activity is positively regulated by the binding of calcium and negatively regulated by the endogenous inhibitor, calpastatin (CAST). We have revealed a novel role for CAST in attenuating macrophage activation. While calpain is constitutively expressed in macrophages, CAST levels increase upon activation of macrophages and decreases cleavage of specific calpain targets. Interestingly, we found that CAST increased when macrophages were stimulated with LPS, IFNγ, and TNFα, but not with IL-4, -10, or -17A. We utilized siRNA to inhibit the increase in CAST protein levels that arises from stimulation with TNFα, and decreased CAST expression led to increased NF-κB nuclear translocation and over-production of IL-6 upon stimulation with CpG DNA. CAST knockout mice were examined for markers of inflammation, and results showed that CAST-deficiency led to increased inflammation in the colons of these mice. In addition, serum levels of the pro-inflammatory chemokine, MCP-1, was increased in CAST knockout mice compared to wild-type mice. Overall, CAST plays a key role in limiting macrophage activation and defects in CAST expression increase susceptibility to the development of inflammation in vivo.
Identification of novel subsets of CD5+ B-1a cells reveals layered populations with distinct innate-like functions (67.2)
Authors: Wang Hongsheng , Shin Dong-Mi , Abbasi Sadia , Kovalchuk Alexander , Jain Shweta , Morse Herbert 
Published: January 2023

Abstract
B-1a cells are found to contribute significantly to circulating natural antibodies and mucosal immunity as well as to immunoregulation. These various functional attributes of B-1a are often presented as reflecting the repertoire of all B-1a cells, while understanding how these functions are fulfilled at the clonal level is rather limited. Here we show that B-1a cells can be subdivided into two distinct stable subsets based on differing expression of the plasma cell alloantigen 1 (PC1), also known as ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1), an enzyme involved primarily in hydrolysis of ATP at the cell surface. One subset that we term PC1lo, expresses ENPP1 at low levels, whereas the second subset, designated PC1hi, expresses ENPP1 at high levels. These subsets are distinguishable by gene expression profiles, VH gene usage and time of development. Adoptively transferred PC1lo cells secret significantly more circulating natural IgM and intestinal IgA than PC1hi cells. In contrast, PC1hi cells produce more IL-10 than PC-1lo cells when stimulated with LPS and PMA. Furthermore, PC1lo cells generate antigen-specific IgM responses to pneumococcal polysaccharide antigens whereas PC1hi cells do not. We conclude that the classic B-1a functions segregate quite cleanly between these two subsets and the identification of PC1lo and PC1hi cells extends the concept of a layered immune system.
Bacterial lipopeptides and heat-killed Staph aureus modulate lung vascular endothelial permeability via Toll-like receptor 2 (TLR2) (67.3)
Authors: Hellman Judith , Wilhelmsen Kevin , Mesa Kailin , Xu Fengyun 
Published: January 2023

Abstract
Background: Endothelial cell (EC) TLR2 activation modulates endothelial permeability. We hypothesized that heat-killed Staph aureus (HKSA) induces lung vascular permeability via TLR2, and mapped out the role of NF-κB and MAP kinases in TLR2 agonist modulation of EC permeability. Methods: Electric Cell-substrate Impedance Sensing was used to quantify permeability of lung microvascular EC (LMVEC) monolayers treated with bacterial lipopeptides or HKSA. Signaling pathways were probed by inhibiting MAP kinases and NF-κB. Lung permeability was assessed after IT challenge with HKSA. Results: Bacterial lipopeptides had a biphasic effect on permeability of human LMVEC, with an initial decrease at 1-2 hours that was JNK-dependent, followed by a sustained increase that was NF-κB-dependent. HKSA also induced LMVEC permeability. Anti-TLR2 IgG reduced the HKSA-induced LMVEC permeability. The permeability effects of HKSA were also reduced in LMVEC from TLR2 KO versus WT mice. IT challenge with bacterial lipopeptide and HKSA induced lung vascular leak in mice via TLR2. Conclusions: Bacterial lipopeptides and HKSA modulate endothelial and lung vascular permeability via TLR2. We speculate that the early TLR2-induced reduction in permeability may serve to limit spread of bacteria out of the vascular space, thereby reducing the development of tissue foci of infection, whereas the later increased permeability facilitates WBC trafficking and later reparative processes during active infection.
CD163/WC1 functions as pattern recognition receptors and co-receptors for the gamma delta TCR (68.17)
Authors: Chen Chuang , Herzig Carolyn , Hsu Haoting , Telfer Janice , Baldwin Cynthia 
Published: January 2023

Abstract
γδ T cells are deemed critical to immune surveillance and protection since they are found as resident cells in many organs and tissues including in humans, cattle and mice. It is known that γδ T cells contribute to cellular immunity and protection against important pathogens, organizing granulomas in response to Mycobacteria and producing IFNγ following vaccination to Leptospira. However, it is not clear how best to engage γδ T cells and few efforts have directly addressed the contribution of co-receptor stimulation for doing so. We are filling this gap by addressing the hypothesis that the CD163/WC1 co-receptors on γδ T cells, as an example of PRRs on nonconventional T cells, can be exploited to fully activate these cells when combined with TCR activation. In this study, the complexity of the WC1 multi-gene family in cattle has been resolved. The WC1 family is composed of 13 genes with three structural forms whose sequences are conserved among individual cattle and breeds. These three structural forms have different intracytoplasmic tail sequences which require phosphorylation of distinct tyrosines for transmission of signaling through the TCR and lead to different functional outcomes. In addition, the specific activation of subpopulations of γδ T cells can be defined by the WC1 gene products expressed. The work will inform how PRR families might be exploited for efficacious vaccine design to activate nonconventional T cells that bridge innate and adaptive immune responses.
Leucine rich repeats and calponin homology containing protein 4 (Lrch4) is a novel regulator of Toll-like receptor signaling (68.8)
Authors: Aloor Jim , Gowdy Kymberly , Azzam Kathleen , Madenspacher Jennifer , Draper David , Guardiola-Bright John , Merrick Alex , Dhungana Suraj , Fessler Michael 
Published: January 2023

Abstract
Toll-like receptor (TLR)4 signaling involves assembly of multi-protein complexes in lipid rafts. We identified Leucine rich repeats and calponin homology containing protein (Lrch)4 in a proteomic screen as a protein recruited to rafts of lipopolysaccharide (LPS)-exposed macrophages. Lrch4 had no published function, but structure predictions, including a transmembrane domain and leucine rich repeats, were suggestive of a receptor. Subcellular fractionation studies verified Lrch4 localization to the plasma membrane. qRT-PCR of 14 mouse tissues revealed that Lrch4 is ubiquitous. Lrch4 silencing in RAW 264.7 cells using lentiviral shRNAs and siRNAs attenuated LPS induction of TNFα and activation of mitogen-activated protein kinases and NF-κB. Lrch4 knockdown also reduced TNFα induction by ligands to several other TLRs. Lrch4 knockdown in TLR2 or TLR4 stable MD2-CD14-293 cells revealed that Lrch4 regulates human TLR but not TNFα -receptor signaling. Lrch4 and MD2 co-precipitated with biotin-LPS, and Lrch4 knockdown reduced cell binding of biotin-LPS without altering surface display of TLR4, together suggesting that Lrch4 interacts either directly or indirectly with LPS as part of a receptor complex. Lrch4 moreover co-precipitated with both MyD88 and TLR2. Lentiviral shRNA-mediated knockdown of Lrch4 in the murine airway reduced LPS-induced neutrophil influx into the airspaces in vivo. Taken together, we hypothesize that Lrch4 is a novel regulator of the innate immune response.
Enhanced T cell activation in lymphocytes from transgenic mice expressing LAT molecules resistant to ubiquitination (69.5)
Authors: Rodriguez-Pena Ana B. , Balagopalan Lakshmi , Gomez-Rodriguez Julio , Kortum Robert L. , Feigenbaum Lionel , Sommers Connie L. , Samelson Lawrence E. 
Published: January 2023

Abstract
Linker for activation of T cells (LAT) is critical for the propagation of T cell signals from the plasma membrane to the cytoplasm upon T cell activation. Previous studies demonstrated that substitution of LAT lysines with arginines (2KRLAT) resulted in a decrease in LAT ubiquitination and elevated T cell signaling, indicating that LAT ubiquitination is a molecular checkpoint for attenuation of T cell signaling. To investigate the role of LAT ubiquitination in vivo, we have generated transgenic mice expressing WT and ubiquitin-defective 2KRLAT. Upon TCR stimulation, proximal T cell signaling was elevated in lymphocytes expressing 2KRLAT versus WT cells as evidenced by higher levels of phospho(p)-tyrosine proteins, p-LAT, p-phospholipase C-gamma and cytosolic calcium flux. Evaluation of various cell surface markers also revealed an enhanced memory T cell profile in 2KR lymphocytes. Moreover, upon TCR stimulation, a higher percentage of T cells expressing greater levels of effector molecules such as intracellular interferon-gamma, tumor necrosis factor-alpha and interleukin-2 was found in 2KR versus WTLAT mice. We have thus identified enhanced proximal T cell signaling, an enhanced memory T cell profile and higher expression of cytokine effector molecules in lymphocytes from 2KRLAT transgenic mice. These results suggest that 2KR mice may respond more efficiently to pathogenic challenges, an hypothesis that will be tested in various experimental models of mouse infection.
Antigen specific changes of CDR3 fragment distribution of Vδ2 chain of human γδ T cells stimulated by Mycobacterium tuberculosis heat resistant antigen (70.11)
Authors: Li Baiqing , Ma Fei , Guo Shujun , Lü Hezhuo , Xue Zhuping 
Published: January 2023

Abstract
Recent studies show that phosphate antigen activated γδ T cells fail to, but Mycobacterium tuberculosis (Mtb) activated γδ T cells potentially inhibit intracellular Mtb growth, and BCG-stimulated γδ T cells display more restricted TCR diversity than phosphate activated γδ T cells. Mtb heat resistant antigen (Mtb-HAg), peptide antigen, has been shown to preferentially stimulate Vγ9Vδ2 T cells. However, the characteristics of diversity of TCR Vδ2 region of Mtb-HAg stimulated Vγ9Vδ2 T cells has not been investigated. In this study, by using size-spectratyping analysis of length of complementarity-determining region (CDR) 3 fragment of Vδ2 gene, the length of the predominant peaks of CDR3 fragment of Vδ2 gene in γδ T cells that stimulated by Mtb-HAg was significantly larger than that in γδ T cells cultured with IL-2 only and that in fresh PBMC groups. However, there were no significant different changes in the variations and length of CDR3 fragment of all other subfamilies of V gene of γδ T cells stimulated with Mtb-HAg. By sequencing Vδ2-CDR3 transfected clones, Vδ2-CDR3 regions showed two conserved “CACD” and “FGXG” at the N-terminus and the C-terminus, respectively. In conclusion, our results indicate that biased distribution of CDR3 fragment of Vγ9Vδ2+ T cells stimulated by Mtb-HAg is antigen specific changed and the clonally restricted. There might be important implications for the development of prophylactic vaccines related to protective and pathogen-specific γδ T cells.
Campylobacter jejuni modulates mucosal immune responses in the murine small intestine (70.13)
Authors: Maue Alexander , Mohawk Krystle , Hill Christina , Poly Frederic , Ferderber Jason , Patterini Dawn , Guerry Patricia 
Published: January 2023

Abstract
Campylobacter jejuni is among the most common causes of diarrheal disease worldwide. Evidence of immunity to C. jejuni following natural infection has been documented; however, relatively little is known regarding the mucosal immune response and correlates of protection against C. jejuni. To determine the role that the capsular polysaccharide (CPS) of C. jejuni plays in colonization and its effect on cytokine production by intestinal T cells, we utilized a mouse intestinal colonization model following oral infection with either CPS-deficient or wild type (CPS-replete) strains of C. jejuni. Initially, mouse colonization levels were similar between strains. Around 7 days post-infection, a significant reduction in bacterial shedding was seen in mice infected with the CPS-deficient strain. The production of IFN-γ and IL-17 was analyzed in lymphocytes from the epithelium, lamina propria and Peyer’s patches at various timepoints post-infection. IL-17 expression was significantly higher in lamina propria and Peyer’s patch CD4+ cells from mice infected with CPS-deficient bacteria compared to mice infected with wild type C. jejuni. Additionally, the percentage of CD8+ intraepithelial lymphocytes expressing IFN-γ was increased in mice infected with CPS-deficient bacteria. These data suggest that the production of IFN-γ and IL-17 is associated with clearance of unencapsulated C. jejuni from the mouse intestine and that CPS modulates cytokine production from intestinal T cells.
Qa-1b deficiency results in increased inflammatory response in aerogenic Mycobacterium tuberculosis infection (70.14)
Authors: Bian Yao , Shang Shaobin , Shanmuganad Sharmila , Wang Chyung-Ru 
Published: January 2023

Abstract
The murine MHC Ib molecule Qa-1b is known to play roles in both antigen presentation during infection by intracellular pathogens, as well as an immunoregulatory role in autoimmune and viral infection disease models. It has been shown that Qa-1b is able to suppress NK cell and CD8+ T cell activity through the interaction of Qa-1b /self-peptide complexes with inhibitory CD94/NKG2A molecules on activated effector cells. We find that Qa-1b expression is upregulated on a variety of cell types in a mouse model of low-dose, aerogenic infection with Mycobacterium tuberculosis (Mtb). Further, Mtb-infected, Qa-1b -deficient mice demonstrate increased production of INF-γ and IL-17A as compared to wild-type mice, suggesting that Qa-1b primarily plays an immunoregulatory role in Mtb infection. Qa-1b -deficient mice also display increased expression of inhibitory CD94/NKG2A complexes on CD8+ T cells during infection, indicating a potential mechanism by which Qa-1b is able to control immune responses during Mtb infection.
Deficiency of prolactin-inducible protein leads to a lower Th1 immune response in vitro and in vivo (70.2)
Authors: Li Jintao , Liu Dong , Blanch Anne , Jia Ping , Myal Yvonne , Uzonna Jude 
Published: January 2023

Abstract
The prolactin-inducible protein (PIP) is a secretory protein strategically located at several ports of pathogen entry into the body and hence might play a role in the first line of immune defense against invading pathogens. To date, there are no studies that address the contributions of PIP against infection. Our previous studies show that PIP knockout (KO) mice had enlarged submandibular lymph nodes and thymic medulla. Here, we assessed the phenotype and responsiveness of immune cells from PIP KO mice to polyclonal T cell stimulators and model antigens in vitro and in vivo. We found that PIP KO mice have comparable numbers or frequency of immune cells, including T, B, natural killer and dendritic cells. In depth phenotypic analysis revealed that the PIP KO mice had slightly but significantly lower numbers of CD4+ T cells in their spleens and lymph nodes. Furthermore, CD4+ T cells from PIP KO mice showed significantly decreased proliferation, IL-2 production and impaired differentiation into Th1 subsets in vitro. The impaired in vitro Th1 response was confirmed in vivo where CD4+ T cells from OVA-immunized PIP KO mice showed significantly impaired proliferation and IFN-γ production following restimulation with OVA. Collectively, our findings implicate PIP as an important CD4+ modulatory protein that enhances Th1 cell response, and suggest that this protein might play critical roles in cell-mediated immunity and resistance to intracellular pathogens.
Goblet cell-associated antigen passages and luminal antigen delivery to intestinal dendritic cells (71.6)
Authors: Miller Mark , McDole Jeremiah , Wheeler Leroy , McDonald Keely , Knoop Kathryn , Newberry Rodney 
Published: January 2023

Abstract
Understanding how pathogen-specific immunity is elicited in the gut against the overwhelming background of foreign antigens from food and normal flora is essential for treating intestinal infections and inflammatory diseases. Oral tolerance is mediated in part by intestinal dendritic cells (DCs) that promote the development of regulatory T cells. Beneath the villous epithelium, the lamina propria (LP) contains a large population of DCs (CD11c+ CD11b+ MHCII+ cells), CD103+ CX3CR1- DCs, which can promote IgA production, imprint gut homing on lymphocytes, and induce the development of regulatory T cells, and CD103- CX3CR1+ DCs, which can contribute to TNFα production, colitis, and the development of Th17 T cells. How luminal antigens are captured by LP-DCs in the steady-state is controversial. Using a combination of in vivo two-photon imaging and ex vivo analyses we show that goblet cells (GCs) within the small intestine function as passages to deliver low-molecular weight antigens from the intestinal lumen to underlying CD103+ LP-DCs, a phenomenon we have termed goblet-cell associated antigen passages (GAPs). The preferential delivery of antigens to CD103+ LP-DCs has important implications for peripheral tolerance induction at the mucosa. The mechanisms that regulate GAP function during homeostasis and pathogenic infection are the focus of ongoing work.
Higher numbers of Gr1hiCD11b+ cells suppress B cell differentiation and autoantibody production in male BWF1 mice (72.7)
Authors: Trigunaite Abhishek , Khan Ayesha , Der Evan , Jorgensen Trine 
Published: January 2023

Abstract
(NZBxNZW) F1 (BWF1) mice spontaneously develop a lupus-like disease characterized by elevated levels of anti-nuclear autoantibodies (ANA) and systemic inflammation and with a similar female bias as observed in humans. Bone marrow (BM) chimera studies have shown intrinsic disease-driving properties of female BM cells and subsequent flow-based analyses identified significantly less Gr1hiCd11b+ myeloid cells in BWF1 female mice as compared to males. As Gr1hiCD11b+ cells have been suggested to be immunosuppressive, we hypothesized that these cells suppress B cell activation and differentiation and protect against lupus-like disease in male BWF1 mice. We analyzed the effect of male and female Gr1hiCD11b + cells on 1) cytokine-driven B cell differentiation in vitro, 2) antibody responses to immunization, and 3) spontaneous autoantibody production. We found that Gr1hiCD11b+ cells from both male and female 4 wk old BWF1 mice significantly suppressed cytokine-driven plasma cell differentiation in vitro in a dose dependent manner. Likewise, treatment of male BWF1 mice with depleting anti-Gr1 antibody resulted in elevated antibody response to Np-CGG immunization. And finally, spontaneous production of ANA were significantly increased in male BWF1 mice during and after anti-Gr1 antibody treatment, with ANA levels comparable to those of unmanipulated BWF1 females. These data suggest a new and important role for immunosuppressive Gr1hiCD11b+ cells during antibody-mediated autoimmunity.