bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-18-MyD88 signaling axis is important in the attainment of a robust virus-specific effector NK cell response but dispensable for memory formation (P1248)
Authors: Madera Sharline , Sun Joseph 
Published: January 2023

Abstract
Although natural killer (NK) cells are considered part of the innate immune system, studies have demonstrated the ability of NK cells to contribute to potent recall responses similar to T and B cells. The precise signals that promote the generation of a long-lived NK cell response are largely undefined. Using cytokine and cytokine receptor deficient mice we investigated the role of the pro-inflammatory cytokine IL-18 on NK homeostasis, activation, expansion, and memory cell formation in response to mouse cytomegalovirus (MCMV) infection. We demonstrate that IL-18 receptor-deficient (IL-18RKO) NK cells exhibit a defect in NK cell expansion following MCMV infection; however, the generation of IL-18RKO memory NK cells was unaffected, as IL-18RKO and wildtype NK cells were detected greater than 5 weeks following MCMV challenge. NK cells deficient in MyD88, the adapter protein which mediates signaling downstream of the IL-1 and IL-18 receptors, also showed a similar defect in expansion. No defect was observed in IL-1RKO NK cells. Interestingly, IL-18RKO NK cells exhibit comparable homeostatic proliferation as wildtype. Thus, these data together highlight the importance of an IL-18-MyD88 signaling axis in NK cell priming, and in the attainment of a robust virus-specific effector NK cell response. Understanding the full contribution of the signals necessary for a protective anti-viral NK cell response will be of interest in the development of vaccines and therapeutics.
The abundance of memory-like T cells depends on TCR/MHC interactions (P1442)
Authors: Kazansky Dmitry , Silaeva Yulia , Kalinina Anastasia , Vagida Murad , Khromykh Ludmila , Deikin Alexei , Ermolkevich Tatiana , Sadchikova Elena , Goldman Igor 
Published: January 2023

Abstract
To investigate impact of TCR transgenic chains in formation of activation surface phenotype of T lymphocytes, we have generated mouse strain expressing transgenic beta-chain of TCR 1D1 (belonging to Vbeta6 family) on genetical background B10.D2(R101). Genomic sequence encoding TCR 1D1 beta-chain was isolated from memory T-hybridoma specific to Kb molecule. In thymus of transgenic mice accumulation of CD4-CD8-CD3- T lymphocytes takes place on the rate exceeding by several times the number of these cells in wild type animals. In transgenic animals about 70-80% of peripheral T lymphocytes express Vbeta6, whereas the percent of these cells does not exceed 5-7% in wild type animals. The ratio of peripheral CD4 and CD8 T lymphocytes stayed unchanged in transgenic mice. The percent of T cells with naive phenotype CD44-CD62L+ was significantly increased, whereas the levels of effector memory CD44+CD62L- and central memory CD44+CD62L+ T lymphocytes were markedly decreased. T lymphocytes expressing endogenous beta-chains mostly had the phenotype of memory-like T cells. Expression of 1D1 beta-chain was associated with naïve phenotype and lowered MLR-responses. These results suggest that appearance of memory-like T cells depends on interactions between TCRs and endogenous MHC/peptide complexes, whereas abundances of naive and memory-like T cells are regulated by competition of naive T cells for restricted number of appropriate MHC/peptide complexes in lymphoid tissue.
Infant immune activation, HIV susceptibility and ochratoxin A exposure in Khayelitsha, South Africa (P6159)
Authors: Wood Lianna , Jaspan Heather , Sodora Donald 
Published: January 2023

Abstract
In Khayelitsha, South Africa, 25% of new mothers are HIV-infected, and despite HIV acquisition through breast milk, WHO guidelines recommend breastfeeding to reduce infant mortality. One unexplained observation is that mixed fed infants (breast milk with formula/cereals) have up to an 11 fold increased risk of HIV acquisition. We hypothesized that this increase in HIV susceptibility is due to higher immune activation in response to non-breast milk foods. In fact, using non-invasive oral mucosa sampling, we observed increased CD4+ cells in mixed fed infants by flow cytometry. One immunomodulatory factor that may induce this immune activation in mixed fed infants is the common food contaminant Ochratoxin A (OTA). We measured OTA levels in plasma samples from infants in Khayelitsha, and found that at 2 weeks of age all infants had low OTA levels. However, at 6 weeks of age, OTA levels increased by 2 fold only in non-breastfed infants. Additionally, OTA plasma levels positively correlated with plasma levels of CXCL10 and TNF-alpha and negatively with IFN-alpha. Together, these data show that: 1. mixed fed infants have increased mucosal HIV target cells, 2. infant foods in Khayelitsha are contaminated with OTA, and 3. OTA exposure correlates with increased inflammatory and decreased antiviral activity in infant plasma. These findings suggest a mechanism for increased HIV susceptibility in mixed-fed infants and a role for food contaminants in infant HIV susceptibility.
Role of MGL and galectin-1 cross-talk in the regulation of T cell apoptosis (P1288)
Authors: Ilarregui Juan , García-Vallejo Juan , Rabinovich Gabriel , van Kooyk Yvette 
Published: January 2023

Abstract
Recently we showed that the interaction of MGL, expressed by tolerogenic dendritic cells (DCs), with GalNAc-decorated CD45 on effector cells inhibits T cell function leading to T cell death. The LacNAc binding lectin Gal1 also binds CD45 inducing apoptosis of Th1 and Th17 effector T cells. However, whether these lectins may act in concert to control effector T cell functions remain to be explored. Firstly, we incubated both lectins with Jurkat T cells and measured apoptosis by annexin V. We found higher and faster apoptosis induction compared to each lectin alone. A mechanistic analysis of this result by ImageStream® technology revealed that MGL triggers Gal1 expression that later colocalizes with CD45 in the membrane inducing high levels of receptor clustering and, in this manner, leads to augmented apoptosis. This effect is CD45 mediated and T cell specific, since Jurkat T cells devoid of this receptor or CD45-expressing carcinoma or adenocarcinoma cell lines are protected from apoptosis when incubated with MGL. Next, we isolated and activated mouse CD4+ T cells and showed that MGL1 but not MGL2 homologue induces apoptosis. However, there is no additive effect in primary CD4+ T cells. Although more work is required to fully elucidate the observed effects, these results indicate that both MGL and Gal1 may modify effector T cell function, through the interaction with specific CD45 glycoforms, potentially contributing to the homeostasis of the immune response.
Dysregulated neutrophil function promotes chronic intestinal parasite infection (P3068)
Authors: Hughes Michael , Antignano Frann , Snyder Kim , Gold Matthew , Oudhoff Menno , Zaph Colby , McNagny Kelly 
Published: January 2023

Abstract
Clearance of intestinal helminth infection and acquired resistance is dependent on an appropriate type-2 immune response. In the Trichuris muris (Tm) infection model in mice, resistant strains expel worms via a Th2 cell-mediated response whereas susceptible strains produce high levels of Th1 cell-associated cytokines and become chronically infected. Myeloid-cell specific deletion of Ship1 (SHIPΔLysM) in a normally resistant mouse strain (C57Bl6) results in chronic infection because of inappropriate production of IL12 in the intestine and mesenteric lymph nodes (mLNs) in Tm-infected mice. Although Ship1-deficient macrophages overproduce IL12 in vitro and in vivo and thus likely contribute to the Tm-susceptibility of SHIPΔLysM mice; surprisingly, deletion of Ship1 in the neutrophil lineage alone (SHIPΔPMN) is sufficient to render a resistant strain susceptible. Chronic worm burden in SHIPΔPMN mice is associated with elevated IL12, IFNγ and decreased IL13 production in the intestine and mLNs. These data suggest that regulation of neutrophil function by Ship1 is required for parasite clearance in response to Tm infection. Although neutrophils are rapidly recruited to the intestine following Tm infection, neutrophils are not required for clearance of parasites. However, our results suggest that dysregulated neutrophil activity can contribute to chronic parasitic infection.
Role of heme oxygenase in the immune response to Mycobacterium tuberculosis in humans (P3095)
Authors: Collins Angela , Marciano Denise , Graviss Edward , Shiloh Michael 
Published: January 2023

Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is the cause of over two million deaths every year. We have previously shown that in mice, Mycobacterium tuberculosis infection induces the production of heme oxygenase, and the subsequent production of carbon monoxide gas is sensed by the bacteria to initiate a dormancy program. Mouse macrophages deficient in heme oxygenase are defective in controlling intracellular Mycobacterium tuberculosis infection and mice deficient in heme oxygenase succumb to disease more readily than wild type mice. While the mechanisms used by mouse macrophages to control intracellular Mycobacterium tuberculosis infection, including nitric oxide synthase, the respiratory burst, acidification and heme oxygenase are well studied; how human macrophages control Mycobacterium tuberculosis infection remains poorly understood. We now show that a polymorphism in the heme oxygenase promoter confers susceptibility to human tuberculosis, that heme oxygenase is induced in human tuberculosis lesions, and that Mycobacterium tuberculosis infection of human macrophages in vitro also induces heme oxygenase. We also show by confocal microscopy that heme oxygenase colocalizes with Mycobacterium tuberculosis in human macrophages, and hee oxygenase enzymatic activity in human macrophages is necessary for inflammatory cytokine production. Thus, we demonstrate an important role for heme oxygenase in controlling Mycobacterium tuberculosis infection.
Nonreplicating Toxoplasma gondii elicits potent antitumor responses (P3100)
Authors: Bzik David , Fox Barbara , Sanders Kiah 
Published: January 2023

Abstract
Toxoplasma gondii stimulates a dramatic host response marked by early IL-12 production and development of IFN-γ and CD8 T cell dependent immune control of natural infection. We demonstrate that intratumoral injection of an engineered nonreplicating nonreverting uracil auxotroph T. gondii strain (cps) elicited potent antitumor responses against established aggressive orthotopic ovarian cancer. IL-12 and IFN- γ were required for this antitumor response and the response was elicited by both type I and type II strains. The antitumor response was not diminished by pre-existing CD8 T cell dependent immunity to T. gondii, and was boosted by additional sequential treatments, suggesting that early IL-12 production was required. However, heat-killed parasites that do not actively invade host cells, parasite secreted molecules, parasite cytosol, and whole parasite extracts failed to stimulate any detectable antitumor response when exogenously introduced into the tumor environment. These results implicate active invasion and intracellular manipulation of host cells by the introduction of parasite-secreted molecules directly into the host cell cytosol as mediators of this antitumor response. To explore this mechanism we developed genetically defined cps strains that lack injected parasite molecules associated with manipulation of cells or host cell IL-12 production. The role of these novel parasite injected molecules in stimulating antitumor responses will be presented.
Neutrophils in pulmonary granulomas from Mycobacterium tuberculosis-infected cynomolgus macaques upregulate granzyme B expression in response to mycobacterial products and pro-inflammatory signals (P3058)
Authors: Mattila Joshua , Sun Tao , Flynn JoAnne 
Published: January 2023

Abstract
The role of neutrophils in tuberculosis (TB) and whether neutrophils can express granzyme B (grzB), a pro-apoptotic enzyme associated with cytotoxic T cells, are controversial. We compared neutrophil and T cell grzB expression in peripheral blood and pulmonary granulomas from cynomolgus macaques to better understand the biology of neutrophils in TB. Flow cytometric analysis indicated that T cells were the dominant grzB-producing cell in unstimulated peripheral blood whereas very few neutrophils expressed grzB. Similarly, neutrophil-depleted PBMCs had significantly more grzB activity than neutrophils. Stimulation with M. tuberculosis culture filtrate, but not peptide antigens, caused neutrophil upregulation of grzB to levels equivalent to stimulation with LPS from E. coli. In contrast to peripheral blood, we found that more neutrophils than T cells expressed grzB in granulomas. Granuloma neutrophils contained significantly more grzB than T cells with respect to the cross-sectional area of the cell occupied by grzB and number of granules per cell. Perforin, a protein required for target cell pore formation and grzB-mediated cytotoxicity, was found on T cells but not neutrophils, suggesting that neutrophils in granulomas may not use grzB as a cytotoxic effector. These data indicate mycobacterial products in the pro-inflammatory environment of granulomas upregulate neutrophil grzB expression and suggest a previously unappreciated aspect of neutrophil biology in TB.
Efficient sensing of infected cells in absence of virus particles by plasmacytoid dendritic is blocked by the viral ribonuclease Erns (P6114)
Authors: Summerfield Artur , Python Sylvie , Ruggli Nicolas 
Published: January 2023

Abstract
Plasmacytoid dendritic cells (pDC) have been shown to efficiently sense HCV- or HIV-infected cells. Here we demonstrate for classical swine fever virus, a member of the Flaviviridae, that this process is much more efficient in terms of interferon-alpha induction when compared to direct stimulation by virus particles. By employment of virus replicon particles which can replicate but not form de novo virions, we exclude a transfer of virus from the donor cell to the pDC. pDC activation by infected cells to pDC was mediated by a contact-dependent RNA transfer to TLR7, requiring intact cytoskeleton, lipid rafts, but not involving membrane vesicles such as exosomes. We further demonstrate that a unique viral protein with ribonuclease activity, the Erns protein of pestiviruses, efficiently prevented this process. This required intact ribonuclease function in intracellular compartments. The present study underlines the importance of pDC activation by infected cells and identifies a novel pathway of virus escaping the interferon system. This pathway of activation could be of particular importance for viruses which are cell-associated and cause persistent infection. Considering that Erns is required for pestiviruses to establish persistent infection of foetuses after transplacental virus transmission resulting in the development of immunotolerant animals, this report also points on a possible role of pDC in preventing immunotolerance after viral infection of foetuses.
Nonclassical monocyte-derived macrophages are essential for preventing pyelonephritis upon urinary tract infection in mice (P4229)
Authors: Partida-Sanchez Santiago , Cortado Hanna , Horvath Dennis , Li Rollin , Flaño Emilio , Justice Sheryl 
Published: January 2023

Abstract
Phagocytes protect the urinary tract from bacterial infections (UTI). Neutrophils are required early upon infection for clearing off bacteria, however much less is known regarding the function of monocyte-derived macrophages during UTI. Two main subsets of blood monocytes can be distinguished by differential expression of the chemokine receptors CCR2 and CX3CR1. To determine the functional role of monocyte-derived phagocytes, we used CX3CR1 and CCR2 deficient mice and monitored the trafficking of monocyte-derived macrophages during the course of uropathogenic Escherichia coli (UPEC) induced UTI. We found that Ly6+hi/CCR2+hi/CX3CR1+low, classical inflammatory monocytes were recruited from the blood to the bladder and kidney at 8-24h after infection. A subset of Ly6+low/CCR2+low/CX3CR1+hi nonclassical blood monocytes was recruited to urinary organs early (4h) after infection. UPEC induced bacterial burden was significantly elevated in the bladder of CCR2 KO but not CX3CR1 KO mice at 16h post-infection, notoriously, CX3CR1 KO mice were unable to clear UPEC at 48h post-infection; instead, bacteria spread from the bladder to the kidney causing pyelonephritis in these mice but not in WT controls. Our studies indicate that classical monocyte derived macrophages are required to clear bacteria from the bladder during early UTI infection, in contrast, nonclassical macrophages are required for preventing later bacterial spreading, and likely the clearance of bacteria in the kidney.
FcγRI-mediated production of superoxide, induction of autophagy and intracellular reduction of Rhodococcus equi load (P4231)
Authors: Bhandari Mahesh , Shivalingappa Prashanth , Gilbertie Jessica , Wiechert Sarah , Jones Douglas , Sponseller Brett 
Published: January 2023

Abstract
Macrophages are the host cells for Rhodococcus equi. Activation of FcγRI can induce phagocytosis, antigen presentation, cytokine production, antibody-dependent cell mediated cytotoxicity, reactive oxygen species (ROS) production, and induction of autophagy machinery in macrophages. Here we demonstrate enhanced macrophage bactericidal activity against intracellular R. equi concurrent with superoxide production and induction of autophagy. Following ligation of IFN-γ, TLR4 and FcγRI receptors, murine bone marrow-derived macrophages, equine pulmonary-alveolar macrophages and monocyte-derived macrophages were tested for superoxide production, induction of autophagy and bacterial load through Image Stream, flow cytometry, western blot and confocal microscopy. Results show that ligation of these receptors alone or in combination enhanced superoxide production and induction of LC3II. Importantly, however, FcγRI activation with a synthetic homodimeric peptide resulted in a sustained effect leading to a profound reduction in bacterial load as compared with other receptor agonists. These data are consistent with the notion that production of superoxide enhances autophagy resulting in reduction of bacterial load in infected macrophages.
Innate immune detection of flagellin positively and negatively regulates Salmonella infection. (P4001)
Authors: Lai Marvin , Quarles Ellen , Lopez-Yglesias Americo , Zhao Xiaodan , Hajjar Adeline , Smith Kelly 
Published: January 2023

Abstract
Salmonella enterica Typhimurium is a flagellated bacterium and one of the leading causes of gastroenteritis in humans. Bacterial flagellin is critical for motility and also a prime target of the innate immune system. Innate immune recognition of flagellin is mediated by at least two independent pathways, TLR5 and Naip5-Naip6/NlrC4/Caspase-1. The functional significance of each of the two independent flagellin recognition systems in innate immunity to wild type Salmonella infection is complex, and contribute to both protection and susceptibility. We hypothesized that this was due to efficient modulation of flagellin expression in vivo and evasion of innate immune detection. Salmonella deficient in the anti-sigma factor flgM overexpress flagellin, are attenuated in vivo, and this attenuation is dependent on flagellin expression. In this study, we used flgM- Salmonella to determine if flagellin recognition by the innate immune system is responsible for the attenuation of flgM- S. typhimurium, and to dissect the contribution of each flagellin recognition pathway to bacterial clearance, inflammation and infection. We demonstrate that caspase-1 controls systemic infection of flgM- S. Typhimurium, and also limits intestinal inflammation and injury. In contrast, TLR5 paradoxically promotes bacterial colonization in the cecum, and attenuates intestinal inflammation. Our results indicate that Salmonella evasion of caspase-1 dependent flagellin recognition is critical for establishing systemic infection and that evasion of TLR5 and caspase-1 dependent flagellin recognition help Salmonella induce intestinal inflammation and establish a niche in the inflamed gut.
Low-dose amphotericin B with murine dialyzable spleen extracts protects against systemic Candida infection in mice (P4053)
Authors: Robledo Avila Frank , Limón Flores Alberto , Pavón Romero Lenin , Hernández Pando Rogelio , Estrada Parra Sergio , Estrada García Iris , Pérez Tapia Sonia 
Published: January 2023

Abstract
Candida albicans is a fungus that causes opportunistic mucocutaneaous and systemic infections. Despite the development of several antifungal agents, mortality of systemic Candida infection remains high. Dialyzable spleen extracts (mDSE) are low molecular weight dialyzable products from immune cells which transmit the ability to express delayed-type hypersensitivity and cell mediated immunity from sensitized donors to non immune recipients. mDSE have been successfully used to treat patients with mucocutaneous candidiasis, but their effectiveness in systemic Candida infection has not been evaluated. In this study low-dose amphotericin B (AmB) was supplemented with mDSE to treat systemic candidasis in mice. We report a marked efficacy of this combined treatment on improvement of survival and reduction of the fungal burden in the kidney, correlating with high levels of serum hepcidin. Histopathological analyses of kidneys showed decrease damage, no inflammation and lower fungal burden than control kidneys. Combined treatment of low dose AmB and mDSE caused an immunomodulatory effect, increasing serum IL-6, as well as kidney IFN-γ and TGF-β1 levels, but downregulating TNF-α and IL-6. In conclusion, our data suggest that low dose AmB plus mDSE help to clear the infectious agent and reduce tissue damage due to excess inflammation, possible by the action of hepcidin.
Persistent inflammation and fibrosis of the lung are long-term complications of sepsis in baboons (P4015)
Authors: Lupu Florea , Silasi-Mansat Robert , Keshari Ravi , Peer Glenn , Popescu Narcis , Lupu Cristina , Taylor Fletcher , Lambris John , Kinasewitz Gary 
Published: January 2023

Abstract
Sepsis-induced inflammation of the lung leads to acute respiratory distress syndrome (ARDS), which may trigger persistent fibrotic responses. We have developed a baboon model of E. coli sepsis-induced ARDS and characterized the long-term (6-24 months) effects of sepsis on the lung. By immunocytochemistry, we detected focal accumulation of neutrophils, M2 macrophages, IL17 and TGF-β positive cells, which indicates persistent inflammation in the lung, months after clinical recovery from the acute sepsis episode. Microscopical and biochemical quantification demonstrated an almost doubling of collagen content amount in the lungs of animals that survived sepsis as compared to age-matched nonexposed controls. Electron microscopy showed myofibroblast accumulation within the alveolar wall. Co-staining for fibroblast and cell proliferation markers demonstrated active cell proliferation in fibroblastic foci. Immunostaining with antibodies to procollagens showed active collagen synthesis within the fibroblastic foci and interalveolar septa. These fibroblasts were also stained with phospho Smad-2 and CTGF antibodies, suggesting that TGF-β signaling was one of the main mediators of fibrosis. In conclusion, we show that E. coli sepsis-induced ARDS triggers chronic inflammation, fibroblast proliferation and collagen deposition in the primate. These long-lasting fibrotic responses perpetuate the lung injury and may contribute to post ARDS morbidity and mortality observed in humans.