bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transgenic inhibition of astroglial NF-κB improves functional recovery in EAE by suppressing chronic neuroinflammation. (50.7)
Authors: Bethea John R , Brambilla Roberta , Shestopalov Valery I , Barnum Scott R 
Published: January 2023

Abstract
In the CNS the transcription factor NF-κB is a key regulator of inflammation and secondary injury processes. Following trauma or disease, the expression of NF-κB-dependent genes is activated, leading to both protective and detrimental effects. Here we show that transgenic inactivation of astroglial NF-κB (GFAP-IκBα-dn mice) resulted in reduced disease severity and improved functional recovery following experimental autoimmune encephalomyelitis (EAE). At the chronic stage of the disease, transgenic mice exhibited an overall higher presence of leukocytes in spinal cord and brain, and a markedly higher percentage of CD8+CD122+ T regulatory cells compared to WT, which correlated with the timing of clinical recovery. We also observed that expression of proinflammatory genes in both spinal cord and cerebellum was delayed and reduced, while the loss of neuronal-specific molecules essential for synaptic transmission was limited compared to WT mice. Furthermore, death of retinal ganglion cells in affected retinas was almost abolished, suggesting the activation of neuroprotective mechanisms. Our data indicate that inhibiting NF-κB in astrocytes results in neuroprotective effects following EAE, directly implicating astrocytes in the pathophysiology of this disease.
Revisiting the effect of anti-VLA-4 monoclonal antibody treatment in experimental autoimmune encephalomyelitis (50.9)
Authors: Ji Niannian Eva , Forsthuber Thomas G. 
Published: January 2023

Abstract
Blocking of adhesion molecule VLA-4 has been shown to ameliorate disease in human MS patients and in experimental autoimmune encephalomyelitis (EAE). We were interested in determining long-term effects of anti-VLA-4 monoclonal antibody (mAb) treatment on persistence and function of myelin-reactive T cells in EAE. Unexpectedly, we found that anti-VLA-4 mAb (PS/2) treated mice succumbed to toxic shock-like death after repeated injection of the mAb. Investigating the underlying mechanism we found that treatment of mice with PS/2 in combination with Pertussis toxin (PTX) which is commonly used to facilitate induction of disease in mouse EAE models resulted in death of the animals. Our results show that CD4+ T cells are critical for this effect and that systemic release of cytokines including IL-1 β and TNF-α may play a role. The results reveal a previously not appreciated effect of VLA-4 antibody treatment in mouse EAE model and could be relevant for the treatment of MS patients.
The lipid environment regulates DM-dependent loading of foreign antigens onto MHC class II in dendritic cells (78.17)
Authors: Berger Adam C. , Roche Paul A. 
Published: January 2023

Abstract
MHCII resides on intraluminal vesicles contained within cholesterol-rich lysosomal compartments in immature DCs. This localization is proposed to allow efficient interaction with the MHCII-like chaperone protein DM (localized to the lysosomal limiting membrane). In this study, we investigated the role of the lipid environment in regulating DM-dependent loading of foreign antigens onto MHCII through the use of U18666A, an inhibitor of lysosomal cholesterol egress. U18666A treated DCs upregulate CD40 and CD86 upon stimulation, have similar cellular MHCII levels, and efficiently internalize and degrade foreign protein antigens. Nevertheless, these DCs have a diminished ability to stimulate naïve antigen-specific T cells. We demonstrate that U18666A pretreatment reduces MHCII-peptide surface expression by 60% and completely inhibits the LPS-maturation induced increase in cellular expression of complexes. Microscopic analysis of U18666A treated DCs shows that MHCII molecules are retained on the limiting membrane of cholesterol engorged lysosomal structures and that these molecules are largely devoid of peptide. MHCII-CLIP levels are also significantly decreased in both immature and mature DCs. We conclude that when MHCII and DM are retained on the same membrane, DM retains the ability to elicit CLIP removal from MHCII, but not to allow efficient peptide loading.
This work is supported by the NCI.
The membrane distribution of MHC-II-peptide complexes and its role in T cell activation (78.18)
Authors: Bosch Pages Berta , Roche Paul A. 
Published: January 2023

Abstract
The efficiency of the interaction between MHC-II-peptide complexes (pMHC-II) and T cell receptor depends on the amount of antigen present at the surface of DCs. MHC-II molecules are constitutively present in plasma membrane lipid rafts, membrane microdomains that are important to induce T cell activation at low antigen doses. In this work we investigated if DCs can possess a specific pMHC-II distribution at the surface that can enhance T cell activation. In murine bone marrow derived mature DCs (mDCs), MHC-II molecules displayed a clustured phenotype. Using an antibody that recognizes specific IAk-HEL pMHC-II complexes, we observed that pMHC-II also showed a clustered distribution on the surface of antigen-loaded mDCs. While DCs treated with LPS for only 12 h had 50% less IAk-HEL pMHC-II complexes at the cell surface than DCs treated for 30 h, both cell types showed a clustured distribution of these complexes. Despite the fact that 12 h DCs expressed less IAk-HEL pMHC-II complexes and less CD86/CD40 molecules at the cell surface, T cell activation was similar using 12 h- or 30 h-mature DCs. We are currently investigating the relationship between pMHC-II complex number and cluster distribution over time with the antigen presenting cell function to elucidate the role of microdomain association of pMHC-II in T cell activation.
This work is supported by NCI.
Inherent plasticity of a T-cell receptor binding interface prior to pMHC recognition (78.2)
Authors: Faraldo-Gómez José D , Dash Banaja 
Published: January 2023

Abstract
Structural and biophysical studies have established that the recognition of antigenic peptide-MHC complexes (pMHC) by T-cell receptors (TCR) involves conformational changes in the so-called CDR loops, which define the binding interface of the TCR. This plasticity is believed to underlie the receptors' cross-reactivity, a key feature given the vast diversity of antigens and the limited T-cell repertoire. It remains unclear, however, whether this plasticity is induced upon recognition of specific pMHC, or whether it is an intrinsic characteristic of the CDR loops. To gain insights into this question, we present results from large-scale, atomically-detailed computer simulations of the molecular dynamics of a TCR in its unliganded form and in complex with two distinct pMHC. Our results indicate that the CDR loops can populate bound-like conformational states prior to the engagement of the pMHC, and thus, that the structural plasticity of the binding interface is indeed inherent. It follows that cross-reactivity of this TCR may not be solely determined by their potential interactions with specific pMHC complexes, but also by the nature of this pre-existing conformational equilibrium.
H. influenzae and M. catarrhalis trigger a potent immune response through activation of dendritic cells (78.23)
Authors: Dew Kristin E , Henry Curtis J. , Mitchell Latoya M. , Hiltbolt Elizabeth M. , Swords W. Edward 
Published: January 2023

Abstract
Otitis media is one of the most common pediatric public health problems worldwide. It is caused by bacterial opportunists that normally reside in the nasopharynx such as non-typeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat). Once established, these infections are largely resistant to clearance by host immune effectors. Much remains to be learned regarding how these pathogens persist in the middle ear. Dendritic cells (DC) are the major antigen presenting cell at mucosal surfaces and are the link between the innate and adaptive immune responses. The goal of this study was to determine if NTHi and Mcat activate DC in vitro, and if these activated DC are able to stimulate effector T cell responses. Mouse bone marrow derived DC were stimulated with NTHi strain 86-028NP or 2019, Mcat strain 7169, or lipooligosaccharide (LOS) and the level of co-stimulatory molecule expression (CD86, CD80, CD44 and I-A[b]) was measured using flow cytometry. Bacteria activated DC were then used to stimulate CD8+ and CD4+ T cells, and their proliferation and cytokine production were measured. The results indicate that both NTHi and Mcat stimulate DC maturation in vitro. Based on this data, it appears that the mechanism of persistence of these agents in otitis media does not involve evasion of antigen presenting cells. Ongoing work in our laboratory will focus on defining why immune effectors fail to resolve these infections.
Statins impair CD1d-mediated antigen presentation (78.5)
Authors: Khan Masood A , Gallo Richard , Gourpura Renukaradhya , Brutkiewicz Randy 
Published: January 2023

Abstract
ABSTRACTStatins are widely used as cholesterol-lowering agents that also decrease inflammation, and target enzymes essential for prenylation, an important process in the activation and intracellular transport of proteins vital for a wide variety of cellular functions. Here, we report that statins impair a critical component of the innate immune response, CD1d-mediated antigen presentation. The addition of specific intermediates in the isoprenylation pathway reversed this effect, whereas specific targeting of enzymes responsible for prenylation mimicked the inhibitory effects of statins on antigen presentation by CD1d as well as MHC class II molecules. This study demonstrates the importance of isoprenylation in the regulation of antigen presentation and suggests a mechanism by which statins reduce inflammatory responses.
The absence of ER trimming alters peptides presented by non-classical MHC class I molecules (78.8)
Authors: Nagarajan Niranjana A , Gonzalez Federico , Shastri Nilabh 
Published: January 2023

Abstract
The nature, function and pathways used to produce peptides for presentation by non-classical MHC class I molecules is poorly understood. Here we show that cells from mice lacking the ER aminopeptidase associated with antigen processing (ERAAP) present an immunologically distinct peptide-MHC class I repertoire. Wild-type mice immunized with ERAAP-deficient cells mount robust CD8 T cell responses specific for peptides presented by classical as well as non-classical MHC I molecules. These CD8 T cells produce pro-inflammatory cytokines and effectively kill ERAAP-deficient target cells in vitro as well as in vivo. Further, peptides presented by non-classical MHC class I molecules are expressed in a tissue-specific manner and elicit CD8 T cell responses both by direct and cross-priming. Thus, ERAAP trims the final peptides presented by classical as well as non-classical MHC class I molecules, and may be involved in trimming peptides for cross-presentation.
This research was supported by grants from the NIH (AI060040) to N.S.; N.A.N. is supported by the Irvington Institute Fellowship Program of the Cancer Research Institute.
CD8 T cell depletion in a chronic asthma model inhibits resolution of lung inflammation (79.12)
Authors: McNamara Jeffrey Thomas , Singh Anurag , Secor, Jr Eric , Guernsey Linda , Lefrancois Leo , Thrall Roger 
Published: January 2023

Abstract
Although the pro-inflammatory role of CD4 T cells in the development of allergic airway disease (AAD) has been extensively studied the role of CD8+ T cells remains controversial. CD8 T cells have been shown to be pro-inflammatory in certain models and suppressive in others. We have previously demonstrated that acute daily OVA aerosol exposure (3-14days) results in AAD while continued daily aerosol (42 days) results in resolution of inflammation and the development of local inhalational tolerance (LIT). This biphasic model uniquely enables the investigation of CD8 T cells in the resolution of AAD and development of LIT. CD8 T cells were depleted after AAD (but prior to LIT) using rat IgG anti mouse CD8α (clone YTS 169AG 101HL). This protocol depleted CD8 T cells by &gt; 95% in the perripheral blood and lymph nodes. Control mice received non-specific rat IgG. Bronchoalveolar lavage (BAL) and lung histology were used to assess lung injury at LIT. CD8 T cell depletion resulted in enhanced lymphocytic perivascular /peribronchial inflammation (H&E) and increased collagen deposition (Trichrome) as compared to the control group. There was no evidence of increased mucus production (PAS), lung tissue eosinophilia or increased eosinophils in the BAL. This suggests CD8 T cells may play a role in development and/or maintenance of tolerance in this model.
Early life chlamydial infection enhances allergic airways disease through age-dependent differences in immunopathology (79.20)
Authors: Hansbro Phil M , Starkey Malcolm R , Horvat Jay C , Kim Richard Y , Phipps Simon , Gibson Peter G , Foster Paul S 
Published: January 2023

Abstract
Chlamydial respiratory tract infections are associated with the development and exacerbation of asthma in both children and adults, but the mechanisms underpinning this association remain unknown. We investigated the effect of the age of chlamydial infection on key features of asthma in later life using mouse models of Ovalbumin-induced allergic airways disease (AAD). Neonatal and infant, but not adult infection resulted in differential and permanent alterations in airway eosinophils, T-cell cytokines and dendritic cells (DCs). Infection of neonates suppressed eosinophil influx into the airways and reduced T-cell cytokine release which correlated with a significant reduction in the number and activation of DCs. In stark contrast, infant infection augmented eosinophil influx and increased T-cell cytokine release which correlated with increased DC numbers and activation. Importantly, both neonatal and infant infections enhanced physiological (mucus secreting cell hyperplasia and airways hyper-responsiveness) responses in AAD in later life, which correlated with enhanced IL-13 expression in the lung. Furthermore, neonatal infection induced substantial alterations in lung structure which was linked with increased TGF-β in lung tissue. Thus, early life infection enhances pivotal features of AAD through age dependent, differential affects on immune responses and lung structure.
A critical role for c-kit on dendritic cells in regulating in T helper cell differentiation and allergic asthma (79.3)
Authors: Krishnamoorthy Nandini , Oriss Timothy , Fei Mingjian , Paglia Melissa , Yarlagadda Manohar , Vanhaesebroeck Bart , Ray Anuradha , Ray Prabir 
Published: January 2023

Abstract
Dendritic cells are integral in instructing the differentiation of T helper cells into Th1, Th2 and Th17 subsets and IL-6 is a key regulator of CD4 T cell differentiation .In this study, we investigated pathways in DCs that promote IL-6 production. We show exposure of DCs to house dust mite (HDM) or the mucosal adjuvant cholera toxin (CT) promotes cell surface expression of c-Kit and its ligand, stem cell factor (SCF), on DCs. This dual upregulation of c-Kit and SCF results in sustained signaling downstream of c-Kit, thereby promoting IL-6 secretion. Intranasal administration of antigen into c-Kit-mutant mice or neutralization of IL-6 in cultures from the lung-draining lymph nodes of immunized wild-type mice blunted the Th2 and Th7 responses. DCs lacking functional c-Kit or those unable to express membrane-bound SCF secreted lower amounts of IL-6 in response to HDM or CT. Expression of the Th2-Notch ligand Jagged-2 was also reduced in DCs from c-Kit-mutant mice in response to CT or HDM and the Th1-inducing adjuvant, CpG oligodeoxynucleotide, did not promote either c-Kit or Jagged-2 expression. DCs expressing nonfunctional c-Kit were unable to induce a robust Th2 or Th17 response and elicited diminished allergic airway inflammation when adoptively transferred into WT mice. DCs generated from mice expressing a catalytically inactive form of the p110delta subunit of phosphatidylinositol-3 (PI3) kinase secreted lower amounts of IL-6 upon stimulation with cholera toxin. Taken together, these results reveal the importance of the c-Kit-PI3 kinase-IL-6 signaling axis in DCs in the regulation of T cell responses.
ROG, repressor of GATA, regulates Th2-driven allergic airway inflammation and airway hyperresponsiveness (79.8)
Authors: Nakayama Toshinori , Hirahara Kiyoshi , Yamasahita Masakatsu 
Published: January 2023

Abstract
Studies of human asthma and of animal models of allergic inflammation/asthma highlight a crucial role for type 2 helper T (Th2) cells in the pathogenesis of allergic asthma. Repressor of GATA (ROG) is a POZ (BTB) domain-containing Kruppel type zinc finger family (or POK family) repressor. A repressive function to GATA3, a master transcription factor for Th2 cell differentiation is indicated. The aim of this study is to clarify the regulatory roles of ROG in the pathogenesis of Th2-driven allergic diseases, such as allergic asthma. We examined allergic airway inflammation and airway hyperresponsiveness in three different mouse models, which use either ROG-deficient (ROG-/-) mice, ROG transgenic mice or adoptive transfer of cells. In ROG-/- mice, Th2 cell differentiation, Th2 responses, eosinophilic airway inflammation and airway hyperresponsiveness were enhanced. In ROG transgenic mice, the levels of eosinophilic airway inflammation and airway hyperresponsiveness were dramatically reduced. Furthermore, adoptive transfer of Th2 cells with increased or decreased levels of ROG expression into the asthmatic mice resulted in reduced or enhanced airway inflammation, respectively. These results indicate that ROG regulates allergic airway inflammation and airway hyperresponsiveness in a negative manner, and thus ROG may represent another potential therapeutic target for the treatment of asthma patients.
Cigarette smoke suppresses in vitro allergic activation of mouse mast cells (80.1)
Authors: Mortaz Esmaeil , Folkerts Gert , Engels Ferdi , Nijkamp Frans P , Redegeld Frank A 
Published: January 2023

Abstract
Abstract
Background: Mast cells are important effector cells in innate or acquired immunity that contribute to host defense. Excessive activation of mast cells can result in the development of allergic diseases, including atopic asthma. Mast cell activation by IgE and specific antigen induces the cells to release spasmogenic, vasoactive, and proinflammatory mediators, which enhance airway smooth muscle contraction, vascular permeability, and inflammatory cell recruitment. Recently, we have demonstrated that exposure of mast cells to cigarette smoke medium (CSM) triggered mast cells to produce chemokines. On the other hand, smoking may decrease the risk of allergic sensitization, which could be explained by a reduced IgE production or a diminished response of mast cells to activation of the IgE receptor.
Objective: In this study, we investigated the effect of CSM on allergic activation of mast cells through IgE and antigen.
Methods: Primary cultured murine mast cells were exposed to CSM and activated with IgE and antigen or lipopolysaccharide (LPS). The releases of granules, production of leukotrienes, chemokines and cytokines was determined in supernatants by ELISA. The effect of CSM exposure on intracellular signaling, especially the NF-κB and Erk1/2 pathways, was analyzed by Western blotting.
Results: CSM suppressed IgE-mediated degranulation and cytokine release, but no effect was observed on leukotriene release. CSM induced phosphorylation of Erk1/2 in mast cells. In CSM-exposed mast cells ATF-1 was phosphorylated after stimulation with IgE/Ag. LPS activated mast cells were not influenced by CSM.
Conclusion: Our study suggests that exposure to cigarette smoke may lead to a
reduced allergic activation of mast cells without affecting their response to activation via e.g. bacterial derived LPS.
Interactions between eosinophils and sensory neurons in atopic dermatitis (80.11)
Authors: Fitch Erin L , Nie Zhengying , Fryer Allison , Jacoby David 
Published: January 2023

Abstract
Atopic dermatitis (AD) is a disease characterized by extreme itch, increased density of nerve terminals in the skin, and a large number of circulating eosinophils. Itch is transmitted by sensory neurons whose cell bodies are located in the dorsal root ganglia (DRG). Extracellular eosinophil products, indicating eosinophil activation, are present at high levels in atopic dermatitis lesions. We used immunostaining to visualize eosinophils and nerves in normal and atopic human skin. Using antibodies to eosinophil major basic protein (MBP) and to the nerve-specific protein, PGP9.5, demonstrated that 20-60% of nerves are physically associated with MBP in atopic skin, while normal human skin contains no MBP. We cultured DRG neurons from mice and showed that they produce eotaxin-1, a chemotactic factor for eosinophils, as well as the adhesion molecules ICAM-1 and VCAM-1. When co-cultured with mouse eosinophils for 24 hours, DRG neurons bind eosinophils. This interaction dramatically alters the morphology of DRG, causing increased branching and longer neurites. Thus, eosinophils and nerves interact in the skin of atopic dermatitis patients. This interaction may mediate increased nerve growth and contribute to the increased sensation of itch in AD.
Peanuts can contribute to anaphylactic shock by activating complement (80.2)
Authors: Khodoun Marat , Strait Richard , Orekov Tatyana , Hogan Simon , Karasuyama Hajime , Herbert De'Broski R. , Köhl Jörg , Finkelman Fred D. 
Published: January 2023

Abstract
Peanut allergy is the most common food-related cause of lethal anaphylaxis, typically persists into adulthood, and can reappear in individuals who have become peanut tolerant. These observations suggest that peanuts have special characteristics that increase their allergenicity. We evaluated whether i.v. injection of water-soluble peanut extract (PE) into unimmunized mice made more susceptible to shock by pretreatment with a β-adrenergic blocker and long-acting IL-4 can induce shock through an innate immune mechanism. We found: 1) LPS-free PE induces dose-dependent shock; 2) PE activates complement in vivo in mice and in vitro in mice and humans; 3) Tree nut extracts, which also cause severe anaphylaxis, also activate complement, while milk and egg white, which cause relatively mild food allergy, do not; 4) C3a, and, to a lesser extent, FcγRs contribute to PE-induced shock; 5) PE-induced shock depends more on macrophages and basophils than on mast cells and is T and B cell-independent; 6) platelet activating factor and, to a lesser extent, histamine contribute to PE-induced shock; and 7) PE and IgE-mediated mast cell degranulation synergistically induce shock in mice that have not been pretreated with IL-4 or a β-adrenergic agonist. These observations suggest that complement activation by peanuts may be a reason for the severity of peanut-induced anaphylaxis.