bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exosome-mediated B cell activation (36.11)
Authors: Saunders Ute , Kearney John F 
Published: January 2023

Abstract
The mature B cell population is divided into splenic follicular (FO) B, marginal zone (MZ) B and B1 B cells by phenotype, localization, and function. MZ B and B1 B cells participate in the early immune response against blood-borne T-independent (TI) antigens to bridge the temporal gap between the innate and adaptive immune response. We previously described the capture and transport of bacteria to the spleen by blood-derived CD11c immature dendritic cells (DCs), which are responsible for initiating immune responses to TI-2 antigens. However, the molecular basis of the DC-B cell interaction is complex, since supernatant (SN) from bacteria-primed DCs alone initiates antigen (Ag)-specific MZ B cell differentiation in vitro. Therefore, we propose that bacteria-primed DCs release factors able to initiate Ag-specific plasmablast generation. Recent findings that DCs secrete exosomes, which have the ability to stimulate T-dependent (TD) immune responses, support our hypothesis. To determine whether exosomes are involved in TI immune responses, we isolated exosomes from SN of bacteria-primed DCs (BMDC) and cocultured them with splenic B cells from M167 heavy chain transgenic (tg) mice expressing a dominant B cell clone, reactive with phosphorylcholine (PC). Using this system, we show that exosomes isolated from SN of Streptococcus pneumoniae primed BMDCs can specifically activate the M167 B cell clones, but not B cells from hen-egg-lysozyme (HEL)-specific MD4 tg B cell mice. These results suggest an involvement of exosomes in Ag-specific MZ B cell differentiation.
MHC Class II Expression and Antigen Presentation Function of Mouse Developing-B Cells (36.12)
Authors: Chen Xinjian , Chen Leo C , Gu Yapeng , Jensen Peter E 
Published: January 2023

Abstract
Developing-B cells (d-BC) in bone marrow (including pro-, pre- and immature B-cells) express MHC class II (MHC-II) for reasons not yet understood. We have studied mouse d-BCs for their MHC-II expression and antigen presentation function. Similar to human d-BCs, mouse d-BCs express MHC-II in the absence of co-stimulatory molecules or CD40, and do not express H2-O. Surprisingly, however, no H2-M expression is identified using antibody specific for H2-Mb2, despite the presence of H2-M activity as indicated by lack of cell-surface CLIP that are identified on H2-M-deficient d-BCs. Real-time PCR reveals only H2-Mb1 but not Mb2 mRNA, suggesting that H2-M activity in the d-BCs is derived from H2-Mb1. In vitro, d-BCs can present both peptide and protein antigens. In mixed lymphocyte cultures, d-BCs only stimulate allogeneic CD8 but not CD4 T cells to proliferate, and the d-BC-exposed CD4 T cells loss their rigor to respond to subsequent stimulation by similar allogeneic dendritic cells. Our results indicate that mouse d-BC selectively express components of the MHC-II antigen processing pathway, can present antigens and appear to be tolerogenic to CD4 T cells.
B220− murine splenic natural killer dendritic cells (NKDC) can acquire MHC II expression and become potent stimulators of T cells (36.14)
Authors: Chaudhry Umer Iqbal , Plitas George , Kingham T. Peter , Raab Jesse , DeMatteo Ronald P. 
Published: January 2023

Abstract
Introduction: NKDC (CD3−NK1.1+CD11c+B220+/−) are novel immune cells with characteristics of NK cells and DC. As NKDC exhibit broad cell surface expression of B220, we explored the functional and phenotypic differences between B220+ and B220− NKDC.
Methods: Phenotype analysis was performed on wild-type (WT) and Flt3L expanded B6 splenic NKDC. WT NKDC were FACS purified based on B220 expression and used in various assays. T cell activity was measured by mixed leukocyte reaction (MLR). Supernatant IFN-γ levels were measured with a cytometric bead array. TLR9 ligand CpG (ODN 1826) and IL-18 were added to some wells. NK cells and DC were used as controls.
Results: B220+ NKDC accounted for 33% of total NKDC, were larger in size, and expressed a higher level of MHC II by flow cytometry. After 24 hr culture in media alone, however, B220− NKDC gained high expression of MHC II and other co-stimulatory molecules (MHC I, CD40, CD80, CD86). Additionally, Flt3L expansion, which activates NKDC, led to a similar high level expression of MHC II on B220+ and B220− NKDC. When cultured in IL-18 and CpG for 72 hr, B220+ NKDC secreted higher levels of IFN-γ (73.3±7.4 vs. 50.1±4.1 ng/ml). Compared to B220+ NKDC, B220− NKDC caused lower allostimulation of T cells in an MLR. However, 2 hr activation with CpG prior to culture lead to an increase (and equalization) in allostimulatory capacity of both NKDC subtypes.
Conclusion: B220− NKDC are an immature subtype of NKDC that possess the capacity to gain MHC II expression and become potent stimulators of allogeneic T cells.
Mycobacterium tuberculosis heat shock protein 70 preferentially activates and delivers antigen to CD11b+ mouse dendritic cells (36.18)
Authors: Guerrero Faimola O. , Jund Michelle D. , Goudy Brian D. , Ingulli Elizabeth G. , Pennell Christopher A. 
Published: January 2023

Abstract
Stress proteins are intracellular chaperones that also function as immune adjuvants, linking innate and adaptive immune responses. Some stress proteins, such as heat shock protein 70, deliver their chaperoned peptides to professional antigen presenting cells and enhance ensuing immune responses up to four orders of magnitude more than peptide alone. The net result is T cell-mediated protection in animal models of viral and tumor immunity. To gain insights into how stress proteins elicit immune responses in vivo, we have tracked mouse dendritic cells activated by a fusion protein containing ovalbumin linked to heat shock protein 70 derived from Mycobacterium tuberculosis (OVA.TBhsp70). We find that lymph node resident and migrant CD11b+ dendritic cells preferentially internalize OVA.TBhsp70, leading to their activation and enhanced ability to cross-present antigen to antigen-specific CD8+ T cells. We will present data regarding the nature of the dichotomy between the responses of CD11b+ and CD8alpha+ dendritic cells to OVA.TBhsp70.
(Supported by NIH grants T32CA009138 (F.O.G.) and R01CA113576 (C.A.P.).
IncuCyteTM, a New Multi-well, Intra-incubator Imaging Technology: Time Lapse Photography of T Cell/Stromal Cell Interactions and Apoptosis. (36.31)
Authors: Lundy Steven K. , Memarsadeghi Sohiel , Neagle Bradley D. , Schroeder Kirk S. , Fox David A. 
Published: January 2023

Abstract
IncuCyteTM, a recently developed digital imaging platform, fits inside cell culture incubators and captures phase contrast images at timed intervals. The design allows for imaging from multiple tissue culture vessels while maintaining the cultures in a stationary position. Interactions of T cell subsets with fibroblast-like synoviocytes (FLS) in the presence or absence of superantigen, SEA, were observed at 10 minute intervals over a 6 day period using IncuCyteTM. Beginning on the first day of co-culture, both CD4+ and CD8+ T cells displayed a close association with FLS only when SEA was present. T cell morphology was enlarged and spread. The T cells were highly active in crawling on the surface of the FLS. Individual T cells appeared to maintain association with the same FLS throughout the duration of observation, and a modest proliferation or accumulation of T cells on the FLS surface resulted in 4–10 T cells bound to each stromal cell. Between 24 and 60 hours, FLS cultured with purified CD8+ T cells and SEA underwent apoptosis with profound morphologic changes being observed within a 30 minute time period for individual cells. Purified CD4+ T cells also induced FLS apoptosis, but the timing was delayed compared to CD8+ T cells. This is the first reported visual demonstration of T cell-mediated apoptosis of fibroblast-like synoviocytes.
Research support from the Dryer Foundation.
Transforming Growth Factor β Inhibition of CD1d-mediated Antigen Presentation (36.5)
Authors: Bailey Jennifer C. , Gourapura Renukaradhya J. , Brutkiewicz Randy R. 
Published: January 2023

Abstract
CD1d is an antigen presenting molecule structurally similar to MHC class I and presents lipid antigens to natural killer T (NKT) cells. We have previously shown that the mitogen-activated protein kinases (MAPK), p38 and ERK1/2, reciprocally regulate CD1d-mediated antigen presentation--p38 activation leads to its inhibition, whereas ERK1/2 activation leads to its promotion. Transforming growth factor β (TGF β) is a strong regulator of immune responses as well as cell proliferation, apoptosis and differentiation, and can induce the activation of p38. Our studies have shown that CD1d-mediated antigen presentation is inhibited by TGF β in murine LMTK fibroblasts expressing CD1d. Similar inhibition occurs after TGF β treatment of bone marrow-derived dendritic cells (BMDC). Our studies are aimed at dissecting the mechanisms by which TGF β influences CD1d-mediated antigen presentation.
This work was supported by NIH grant PO1 AI056097 to RRB.
Antigen presenting cells modified with polyunsaturated fatty acids evade T cell mediated lysis by extracellular release of lipids (36.6)
Authors: Shaikh Saame Raza , Edidin Michael 
Published: January 2023

Abstract
Polyunsaturated fatty acids (PUFAs) can be used as adjuvant immunosuppressants to alleviate symptoms of inflammation associated with obesity, heart disease, autoimmune disorders, and the metabolic syndrome. However, the targets and molecular mechanisms by which PUFAs affect pathways not directly linked to inflammatory processes are poorly understood. In the present study, we tested the effects of the ω-6 PUFA arachidonic acid (AA) and the ω-3 PUFA docosahexaenoic acid (DHA) on antigen presentation through the MHC class I pathway. Treatment of human B lymphoblasts (APCs) with AA and DHA lowered their susceptibility to alloreactive CD8+ T cell lysis. Similar effects were observed for mouse APCs. Peptide specific lysis of PUFA-modified B lymphoblasts by CD8+ T cells transgenic for the 2C TCR was lower than lysis of controls. We found that extracellular release of lipids by PUFA-modified APCs was responsible for the reduction in lysis by cognate T cells. Our data suggest that T cell uptake of molecules from lipid modified APCs may be a mechanism by which T cell responses are regulated in response to dietary intake of fatty acids. In addition, elimination of pathogen-derived peptides could be compromised by using PUFAs as immunosuppressants.
Differential T cell responses to glycoantigens (36.7)
Authors: Neaga Andreea , Cobb Brian A. 
Published: January 2023

Abstract
Adaptive immune responses to proteins derived from extracellular pathogens are mediated by MHCII, leading to CD4+ T cell activation. Recently, it was demonstrated that zwitterionic polysaccharide molecules (glycoantigens), such as PSA from the capsule of B. fragilis, are also presented by MHCII and induce T cell activation. However, unpublished anecdotal data has suggested that some individuals fail to respond to glycoantigens in T cell activation assays. In the present study, blood samples were drawn from volunteers to measure T cell responsiveness as measured by proliferation and cytokine production. The data indicates that glycoantigen presentation can induce the development of a TH1 response characterized by robust production of IFNγ and T cell proliferation as previously reported in the literature. Interestingly, T cells from some individuals fail to proliferate in response to glycoantigen, yet produce high concentrations of IFNγ in a T cell-dependent fashion. These data represent the first documented evidence of differential glycoantigen-mediated T cell responses in humans and lead to questions of restriction and allelic specificity during antigen presentation. A complete understanding of the presentation and recognition of glycoantigens during T cell activation could lead to advances in vaccine design using carbohydrate antigens.
This work was supported by a grant to B.A. Cobb (AI062707).
Successful inhibition in contact hypersensitivity by topical painting of CD86 siRNA oligo (37.14)
Authors: Azuma Miyuki , Ritprajak Patcharee , Hashiguchi Masaaki 
Published: January 2023

Abstract
Induction of a costimulatory molecule CD86 on dendritic cells located in peripheral tissues is a critical event for inducing antigen-specific T cell responses. We here investigated therapeutic effects of transdermal administration of siRNA directed against CD86 on skin allergic diseases. In a hapten-induced contact hypersensitivity model, topical painting of cream-base ointment containing a CD86 siRNA oligo without any special delivery system efficiently inhibited the ear swelling. This effect was dose-dependent and comparable to that of intraperitoneal injection of antagonistic anti-CD86 mAb. Histological analyses of the ears revealed that the numbers of infiltrating cells and CD86+ or MHC class II+ cells in the dermis were markedly decreased in the CD86-siRNA -painted ears. The total cell numbers and the percentages of hapten-carrying CD11c+ dendritic cells (DCs) in the regional LNs 24 h after challenge were significantly decreased by the CD86 siRNA treatment. In addition, the expression of MHC class II as well as CD86 on DCs in the regional LNs was also decreased. These results suggest that the silencing of CD86 in local dendritic cells may induce a marked inhibition of allergen-specific T cell responses in the regional LNs and result in the reduction of peripheral inflammatory responses. The use of CD86 siRNA that targets cutaneous DCs may provide great advantages for clinical treatment for skin allergic diseases.
Aqueous allergenic extracts of Parietaria judaica contain non proteic compounds critical for DC maturation and production of Th2-related cytokines independently from specific sensitization. (37.17)
Authors: De Palma Raffaele , D’Aiuto Elena , Abbate Gianfranco , Fontana Angelo , Gorski Jack 
Published: January 2023

Abstract
The pollen of Parietaria judaica (Pj) is a main source of allergenic sensitization in Mediterranean area and in other countries. Recently, many evidences suggests that pollens are a complex mixture of different compounds able to affect the immune response. Here we show that aqueous extracts of whole pollen, but not protein extracts or purified allergens of Pj, induce maturation of human DC prepared from peripheral blood from both sensitized and non sensitized donors. As assessed by flow cytometry, these cells expressed high levels of HLA-DR, CD80, CD54 and CD86 and were able to strongly stimulate allogenic T cells in MLR. Moreover, the whole-pollen extract induce a strong production of IL-10 and IL-13 and expression of several chemokine receptors. The protein extract, as well as the purified allergen failed to induce DC maturation and stimulated only a weak production of IL-4. These findings were independent from the sensitization status of the donors. Taken together, these results further indicate that pollens should not to be considered merely as a carrier of allergenic proteins but, rather, they are complex antigens and affect directly the immune response in sensitized and non sensitized individuals. Therefore, we propose to reconsider the importance of pollens as complex antigens and to further exploit their ability to elicit different immune responses other than classical IgE-mediated reactions.
Dual functionality of B7-DC-expressing dendritic cells in lung draining lymph nodes: Effects on Th1, Th2, and Th17 (37.8)
Authors: Oriss Timothy B , Arora Meenakshi , Dixon-McCarthy Barbara , Ray Prabir , Ray Anuradha 
Published: January 2023

Abstract
The B7 costimulatory family member B7-DC is expressed on activated, but not resting DCs. It is known to inhibit T cells via binding to PD-1, but in PD-1-deficient animals it reportedly delivers a stimulatory signal via an unidentified receptor. We found that it is differentially expressed on lung lymph node DCs from animals undergoing airway inflammation, and examined the functional consequences of this. One day after 3 daily intranasal immunizations, we observed that a majority of lung lymph node myeloid DCs expressed B7-DC. However, expression rapidly diminished only to be re-expressed by 5 days post-immunization. DCs sorted based upon B7-DC expression 1 day following immunization enhanced T cell cytokine production compared to DCs lacking expression, whereas those isolated 5 days post-immunization stimulated less cytokine production. This effect was evident will all three types of T helper cells (Th1, Th2, and Th17) using several different antigen/adjuvant systems. The results could not entirely be explained by differential expression of PD-1 since similar data was obtained with naïve T cells, which do not initially express PD-1, and with activated T cells, which do. These data support a dual role for B7-DC and further suggest that mature myeloid-type DCs can be both stimulatory or inhibitory based upon B7-DC expression.
(RO1 HL77430 to A.R. and RO1 HL60207 to P.R.)
A rapid method for the isolation of Eosinophils without Ficoll or RBC Lysis (38.1)
Authors: Fairhurst Maureen A , Nauer Melany , Thomas Terry E 
Published: January 2023

Abstract
Eosinophils typically comprise 1–5% of blood leucocytes in non-allergic, healthy humans. Allergic and asthmatic reactions result in activation of eosinophils with resultant release of cytoplasmic granules, cytokines and lytic enzymes. Eosinophils are also mediators of responses against parasitic infections. Many protocols for their isolation stress the avoidance of ammonium chloride lysis as this interferes with eosinophil antigen processing, cytokine responses and alters cell morphology.
We describe a rapid and simple method for the enrichment of eosinophils from normal blood that does not require Ficoll or lysis steps and yields good purity and recovery. Blood was collected with heparin and RBC were removed by HetaSep sedimention. The eosinophils were then enriched using immunomagnetic, column-free negative selection (EasySep®). Briefly, cells were labeled with a cocktail of antibodies targeting unwanted cells. These were then coupled to magnetic nanoparticles and the sample was placed in a magnet. The labeled cells were thus removed leaving unlabeled eosinophils. The entire separation procedure can be automated with a pipetting robot (RoboSep®).
Purity of eosinophils assessed by cytospin and Wright’s stain was 98–99%. By flow cytometry (FACS) eosinophils were defined as CD45+CD66b+ and CD16 negative with low side scatter. Final purity assessed by FACS was 94 ± 3%. Recovery averaged 69 ± 21 (n=11).
Basophils function as initiators rather than effectors in IgE-mediated chronic allergic inflammation, independently of T cells and mast cells (38.6)
Authors: Karasuyama Hajime , Mukai Kaori , Obata Kazushige , Ishiwata Kenji , Watanabe Naohiro , Kawano Yohei , Minegishi Yoshiyuki 
Published: January 2023

Abstract
Basophils have often been considered as minor and possibly redundant “circulating mast cells”. We recently demonstrated that basophils play a pivotal role in the development of IgE-mediated chronic allergic inflammation (IgE-CAI), independently of T cells and mast cells. A single subcutaneous injection of multivalent antigens elicited not only immediate- and late-phase ear swelling but also delayed-onset ear swelling with massive eosinophil infiltration in mice sensitized with antigen-specific IgE. Here, we show that basophils function as initiators of the recruitment of eosinophils and neutrophils rather than effectors of inflammation in IgE-CAI. Even though basophils accounted for only 1–2% of the infiltrating cells in the skin legions, treatment of the IgE-sensitized mice with a newly-developed basophil-depleting mAb during the progression of IgE-CAI resulted in suppression of delayed-onset ear swelling with drastic reduction in numbers of not only basophils but also eosinophils and neutrophils infiltrating in the skin legions. Upon activation with IgE and corresponding antigens in vitro, basophils secreted soluble factors that stimulated skin adherent cells to produce soluble factors capable of attracting eosinophils and neutrophils. These findings indicate a novel mechanism of development of chronic allergic inflammation that is initiated and amplified by basophils.
Substance P stimulates human mast cells and together they activate T cells: Inhibition by luteolin (38.8)
Authors: Kempuraj Duraisamy , Iliopoulou Bettina P , Clemons Anthony , Boucher William , Tagen Michael , Vasiadi Magdalini , House Michael , Wolfberg Adam , Theoharides Theoharis C 
Published: January 2023

Abstract
Mast cells are important effector cells in IgE- and Th2-mediated immune responses. Mast cells are located close to substance P (SP) containing nerves. SP can activate connective tissue-type mast cells, but not mucosal mast cells. Here we examined the effect of SP on (a) mediator release from human umbilical cord blood-derived cultured mast cells (hCBMCs) grown in the presence of stem cell factor (SCF), IL-6 plus IL-4; (b) IL-2 from activated T cells alone or together with mast cells. SP dose-dependently released histamine, tryptase and IL-8 (at 10 μM, release was 72.8 ± 7.42%, 5390 ± 954 ng/106 cells and 1140 ± 103 pg/106cells, respectively) compared to controls (6.3 ± 2.4 %, 397 ± 235 ng/106 cells and 583 ± 40 pg/106 cells, respectively). Addition of mast cells to T cells, activated by anti-CD3/anti-CD28, for 24 h stimulated IL-2 production from 38.4 ± 9.2 pg/ml to 1450 ± 63 pg/ml (p&lt;0.05). Addition of SP (10 μM) to mast cells further stimulated activated T cells to release 1747 ± 279 pg/ml (p&lt;0.05) of IL-2. Pretreatment for 15 min with the flavonoid luteolin (10 μM) blocked (&gt;90%) both SP-induced hCBMCs activation and T cell IL-2 release. Mast cells can superactivate T cells and could constitute a new therapeutic target for diseases such as multiple sclerosis. Luteolin could be used to inhibit this interaction.
This work was supported by Theta Biomedical Consulting and Development Co., Inc. (Brookline, MA).
Changes in syk expression in human basophils (HB) induced by a non-IgE-dependent receptor, LIR7 (38.9)
Authors: MacGlashan Donald , Arm Jonathan , Sloane David 
Published: January 2023

Abstract
Expression of syk in HB is highly variable among subjects and correlates with the ability of the cell to respond to FceRI aggregation. Because evidence suggests a post-translational influence on syk expression, we sought ways that syk could be down-regulated by the activation of non-IgE-dependent receptors. HB express LIR7 and aggregation of LIR7 induces mediator secretion kinetically similar to IgE-mediated release. These studies test whether aggregation of LIR7 reduces expression of syk and whether LIR7 operates through syk to induce histamine release (HR). HB were stimulated with mouse anti-LIR7 and anti-mouse Ab (the combination abbreviated to: aLIR7) and assessed for syk phosphorylation and for changes in syk expression. HR was examined ± the presence of a third generation syk inhibitor. aLIR7 induced syk phosphorylation and a modest loss of syk in 18 hour cultures (14±5% loss, n=11, p=0.013) compared to anti-IgE (53±10% loss). There was a correlation between the amount of syk loss induced by anti-IgE and the loss induced by aLIR7 (r=0.63). There was a correlation, r=0.97, between HR induced by anti-IgE and that induced by aLIR7 (means= 43%&25%). The IC50 for inhibition of aLIR7-induced HR was 0.2 μM (IC50 for anti-IgE was 0.038 μM). Each of these data sets is consistent with a dependence of LIR7 signaling on syk and shows that a non-IgE-dependent stimulus can alter syk expression levels.
Supported NIH-AI20253