bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning tumor immunity through integrin transregulation (P5077)
Authors: Cantor Joseph , Slepak Marina , Ginsberg Mark 
Published: January 2023

Abstract
Recent trials using adoptive cellular immunotherapy for cancer have shown the exciting potential of this approach. However, ex vivo-modified tumor-specific T cells are limited by poor homing to solid tumors. Surprisingly this problem has received relatively little attention. α4 integrins are crucial in governing the migration of T cells to sites of infection and inflammation. Blocking phosphorylation of α4 integrin by mutating Ser988 to Ala prevents release of the adaptor protein paxillin, and boosts LFA-1-dependent migration in trans. We thus generated a mouse with this mutation to test effects on leukocyte migration in vivo. Here we report that the α4(S988A) mutation, which boosts VLA-4/LFA-1 integrin transregulation, selectively increases migration of lymphocytes to both inflammatory and tumor sites; myeloid cell homing was unaffected. Melanoma tumor growth was greatly reduced, associated with increased migration of α4(S988A) T cells to tumors, suggesting that boosting integrin trans-regulation is a promising approach to improve adoptive cellular immunotherapy for cancer.
T cells autonomously disengage from Functionalantigen presenting cells after entering the G1 phase of cell cycle (P5089)
Authors: Ma Zhengyu , Han Huihui , Finkel Terri 
Published: January 2023

Abstract
Activation of naïve T cells requires prolonged engagement with antigen presenting cells (APCs). Once activated, however, T cells need to disengage from the APC, exit lymphoid organs, and migrate to the site of infection to fulfill their functions. Although much has been learned about how T cells stop and engage antigen-bearing APCs, it remains unclear how the interaction between T cell and APC ends. It has been generally assumed that T cell disengagement is a result of diminished antigen presentation by APCs or upregulation of certain chemokine receptors by T cells. Here, using Chinese Hamster Ovary (CHO) cells presenting antigens at a constant level, we demonstrate that T cell disengagement from APC is autonomous and independent of antigen presentation by APCs or exogenous chemokines. The motility of T cells gradually increases over time and T cells start to disengage from APCs before the T cell enters the S phase of the cell cycle. Using phase-specific cell cycle blockers, we confirmed that entering the G1 phase is required for T cell disengagement of APC. Our study suggests that T cells actively end interaction with APCs as soon as they are committed to cell division. This active disengagement may contribute to the efficiency of immune responses by making the APC available to other T cells and by initiating early migration to sites of infection. Our results also suggest a mechanism that links cell cycle control with the actin network driving T cell motility and migration.
Alveolar macrophages regulate the susceptibility of alveolar epithelial cells to influenza A virus infection and the outcome of infection. (P4241)
Authors: Cardani Amber , Kim Taeg , Braciale Thomas 
Published: January 2023

Abstract
Influenza A virus (IAV) is a major human pathogen. Patients with lethal primary influenza pneumonia exhibit severe diffuse lung inflammation, respiratory tract injury, and diffuse alveolar damage. While IAV is cytolytic, the host immune response has recently been appreciated to also be a significant cause of lung injury during IAV infections. To explore the role of alveolar macrophages (AMs) in virus clearance and lung injury/repair during IAV infection, we developed a novel mutant mouse strain with a selective deficiency in the AM compartment. We found that AM deficient mice die following a sub-lethal (in control mice) IAV infection in spite of a normal immune response and virus clearance. However, these mice undergo a rapid decline in O2 saturation at the onset of the adaptive immune response (5-6 dpi) and also demonstrate an increased susceptibility of alveolar type I epithelial cells to IAV infection. Destruction of this critical cell type necessary for oxygen exchange by virus or the adaptive response likely accounts for their loss of lung function and death. Thus AMs may have a critical function in controlling the susceptibility of alveolar epithelial cells to IAV infection and therefore the severity of infection.
Primed effector macrophages mediate rapid worm expulsion after N. brasiliensis infection (P4247)
Authors: Chen Fei , Wu Wenhui , Millman Ariel , Patel Nirav , Gause William 
Published: January 2023

Abstract
The innate immune cell populations that mediate macroparasite expulsion remain largely undefined. We examined the role of innate cells in the immune response to the nematode parasite, Nippostrongylus brasiliensis, hypothesizing that they may mediate the markedly accelerated CD4-independent worm expulsion occurring after secondary inoculation. By three days after secondary inoculation, immunofluorescence microscopy demonstrated a localized infiltrate of macrophages and eosinophils surrounding the L3 in the lung, and lung L3 showed reduced ATP, indicating impaired metabolism. Transfer of macrophages from N. brasiliensis primed WT mice to naïve recipients resulted in accelerated expulsion after primary inoculation, similar to WT mice given a secondary inoculation; this protective effect was blocked when primed macrophages were transferred from IL-4Rα-/- donor mice. Culture of L3 with sorted macrophages from primed WT, but not IL-4Rα-/-, mice resulted in macrophage adhesion to L3, decreased L3 metabolism and increased L3 mortality. Neutrophil (Ly6G+) depletion during priming blocked protective immunity after secondary inoculation and depletion of neutrophils in primed mice blocked protective effects of transferred macrophages in recipient mice and inhibited their in vitro binding to L3. These data indicate that neutrophils in the context of a type 2 cytokine environment prime effector macrophages that can directly bind parasites and mediate worm damage and expulsion.
Radiation-induced depletion of cutaneous dendritic cells: Functional consequences of a breakdown in the cutaneous immunological barrier (P4259)
Authors: Gerber Scott , Cummings Ryan , Ryan Julie , Haidaris Constantine , Lord Edith 
Published: January 2023

Abstract
The United States continues to be a prime target for attack by terrorist organizations in which nuclear detonation or dispersal of radiological material are legitimate threats. These types of attacks could result in devastating consequences to a multitude of individuals in the form of radiation injury to particular organ systems. One of these organs, the cutaneous system, which provides the first line of defense against invading pathogens, is particularly sensitive to ionizing radiation (IR) leaving the host vulnerable to cutaneous pathogen invasion. Our laboratory demonstrated that exposure to IR depleted murine cutaneous dendritic cells (cDCs); a network of cells responsible for forming a cutaneous immunological barrier that is critical in protecting the host against microorganism infection. This IR-induced depletion was caused by a migration of cDCs out of the skin responding to abnormal upregulation of cDC migratory factors, CCR7 and CCL21. As a result, this breakdown in the immunological barrier left the host susceptible to a cutaneous Candida albicans challenge where the pathogen was not contained locally but rather disseminated systemically to the kidneys. Interestingly, a subcutaneous treatment with IL-12 prevented the IR-induced depletion of cDCs offering a potential radiation countermeasure to preserve the cutaneous immunological barrier and perhaps prevent the lethal dissemination of opportunistic pathogens following radiation exposure.
Pregnane X receptor regulates the innate inflammatory response against intracellular bacterial infection (P4209)
Authors: Qiu Zhijuan , Mukherjee Subhajit , Schouten Jonathan , Acharya Nandini , Maher Leigh , Salazar Juan , Cervantes Jorge , Mani Sridhar , Khanna Kamal 
Published: January 2023

Abstract
Pregnane X receptor (PXR) is a member of the nuclear receptor family and is primarily expressed in stromal cells of liver and intestine. It’s well established that PXR regulates the metabolism of xenobiotics. Here we demonstrate that PXR signaling specifically in hematopoietic cells is also essential for regulating innate antimicrobial immune responses. Compared to wild type mice, Pxr-/- animals exhibited significantly higher inflammatory response to intracellular bacteria Listeria Monocytogenes (LM) infection. However, strikingly, despite the more robust innate immune response, Pxr-/- mice were unable to control LM infection. Our data demonstrated that the inflammatory monocyte response was significantly reduced in Pxr-/- mice, and these monocytes produced elevated amounts of TNF-α and reactive oxygen species that are known to induce cell death. We propose that the dysregulated inflammatory response in Pxr-/- monocytes results in their increased cell death and thus elevated bacterial burden. Surprisingly, increased activation of the TLR pathway in Pxr-/- mice was the singular determinant of the susceptibility since Pxr-/-Tlr4-/- mice were efficient in clearing LM. In conclusion, our study for the first time defines a novel role of PXR as a critical negative regulator of the innate immune response. Our results also illustrate the need for exquisite fine tuning and balance of the innate inflammatory pathways to ensure the clearance of an intracellular pathogen.
C-reactive protein exacerbates renal ischemia reperfusion injury (P4021)
Authors: Pegues Melissa , McCrory Mark , Zarjou Abolfazl , Szalai Alexander 
Published: January 2023

Abstract
Renal ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) after kidney transplantation, hypotension, and cardiovascular surgery. Mortality from AKI is high due to incomplete knowledge of the pathogenesis of IRI and the lack of an effective therapy. Inflammation accompanies IRI and increases the blood level of C-reactive protein (CRP), a biomarker of worsened outcomes in AKI. To test if CRP is causal in AKI we subjected wild type mice (WT), human CRP transgenic mice (CRPtg) and CRP deficient mice (CRP-/-) to bilateral renal IRI (both pedicles clamped for 30 min at 37°C then reperfused for 24 h). Serum human CRP level was increased ~six-fold after IRI in CRPtg (11.58 ± 1.40 µg/ml at baseline versus 65.75 ± 7.90 µg/ml at 24 h) but was not elevated by sham surgery wherein kidneys were manipulated but not clamped. Compared to WT, serum creatinine and urine albumin was increased after IRI in CRPtg mice. Histological evidence of kidney damage was greater in CRPtg than in WT, whereas CRP-/- kidneys were protected. RT-PCR analysis of mRNA isolated from whole kidneys subjected to IRI revealed that expression of FcγRs increased in CRP-/- kidneys and markers of macrophage activation indicated a stronger classically activated (M1) macrophage response in CRPtg kidneys. Our finding that CRP exacerbates IRI induced AKI by shifting the balance of beneficial and detrimental FcγRs and macrophages, makes CRP a promising therapeutic target for the treatment of AKI.
The p110δ isoform of PI3K modulates TLR4 signalling and is crucial for survival from endotoxin and Escherichia coli infection (P4023)
Authors: Okeke Emeka , Okwor Ifeoma , Jia Ping , Uzonna Jude 
Published: January 2023

Abstract
Sepsis, a systemic immune response to severe bacterial infection, is a leading cause of death in critical care medicine caused by dysregulated immune response to bacteria endotoxin LPS which is recognised by TLR4. The p110δ isoform of PI3K is expressed mostly on leukocytes and has been shown to be important in leukocyte recruitment to sites of inflammation and infection. We report that pharmacological or genetic inhibition of p110δ signalling led to increased expression of TLR4 upon LPS stimulation an effect which was not observed for p110α and p110β. Differential cell counting showed higher numbers of inflammatory cells in the peritoneum of p110δ knock-in [p110δ(D910A)] mice compared to wild type mice. Macrophages from p110δ(D910A) mice induced higher proinflammatory cytokines compared to WT mice in response to LPS. In addition, absence of p110δ activity led to mortality in an otherwise non lethal dose of LPS accompanied by exaggerated production of proinflammatory cytokines. We authenticate our findings by showing that p110δ(D910A) mice are unable to recover from a non lethal dose of Escherichia coli infection. Thus modulation of p110δ signalling is a potential therapeutic target in acute inflammation and sepsis
Gut commensal flora influence the sterile inflammatory response to ventilated lung ischemia reperfusion injury by altering the activation state of alveolar macrophages and recruitment of differentially-activated neutrophils (P4029)
Authors: Prakash Arun , Sundar Shirin , Hellman Judith 
Published: January 2023

Abstract
Background: Ischemia reperfusion (IR) injury is a sterile inflammatory process occurring in diverse and potentially life-threatening clinical scenarios. Acute lung injury is a major cause of morbidity and mortality in severely-ill trauma patients in part due to IR injury. We previously demonstrated a role for TLR4 and alveolar macrophages in lung IR injury and hypothesize that the gut microbiome contributes to this process. Methods: A surgical model of left pulmonary artery occlusion in mice was used and the nature of the inflammatory response examined. Mice were also pretreated with antibiotics to deplete gut commensal flora in order to investigate their influence on the inflammatory response to lung IR. Results: We demonstrate that the activation state of neutrophils recruited in our lung IR injury model is altered as compared to LPS models. Interestingly, the depletion of gut commensal flora results in a significant reduction in inflammatory cell recruitment to the lung following IR. Alveolar macrophages from these antibiotic-treated mice produce lower levels of inflammatory cytokines when stimulated ex vivo with TLR agonists. This suggests that circulating endotoxin from commensal flora maintain alveolar macrophages in a primed state to respond to lung IR. However, the neutrophils recruited appear to be quiescent. This may represent an evolutionary mechanism to mobilize neutrophils to sites of lung IR, where they are ready to respond only if pathogen is present.
Pancreatic β-cells undergo apoptosis in a TLR4 and macrophage cell-dependent manner (P4031)
Authors: Rosendahl Alexander , Cucak Helena , Mayer Chistopher , Tonnensen Morten 
Published: January 2023

Abstract
To elucidate the expression and effect of TLR4 on pancreatic β-cells, we studied mouse islets and the murine β-cell line MIN6 in the presence of macrophages (MΦ). Diabetic islets had 40% less TLR4+ β-cells, while twice as many TLR4+ MΦ compared to healthy islets. TLR4 activation with LPS induced a 5-10 fold induction of cytokines in healthy and diabetic islets. MIN6 cells were only weakly TLR4+ and did not produce cytokines in response to LPS. LPS stimulated diabetic systemic MΦ released 3-10 fold more cytokines per cell compared to healthy MΦ. Interestingly, diabetic MΦ co-cultured with MIN6 cells secreted higher levels of cytokines compared to MΦ alone. We also measured apoptosis in healthy and diabetic islets treated with LPS and found no effect. However, a 3-fold induction of MIN6 apoptosis was obtained when co-cultured with diabetic MΦ and 2-fold when cultured with media from LPS activated MΦ. Taken together, our data suggest that the majority of the TLR4 response in the islet appears to be mediated through MΦ. Moreover a cell-dependent MΦ- β-cell interaction appears to contribute to the enhanced local immunity in the islet. Thus targeting either TLR4 or macrophages may provide a novel treatment regime for type 2 diabetes.
IL-12 regulates psoriatic plaque formation by inhibiting γδ T cells (P4033)
Authors: Kulig Paulina , Haak Stefan , Pantelyushin Stanislav , Gyülveszi Gabor , Sallusto Federica , Becher Burkhard 
Published: January 2023

Abstract
Cytokines are key mediators of immune responses and IL-23 is a critical player in psoriasis pathogenesis. New effective monoclonal antibody directed against common subunit p40 of both IL-12 and IL-23 is currently used in clinics to treat plaque type psoriasis. Recently was shown that Aldara cream, a drug commonly used in the treatment of benign skin disorders, is a potent stimulator of psoriasis-like plaque formation and implicates proinflammatory cytokines like IL-17A, IL-17F and IL-22 in the disease pathogenicity. Using this model we found that mice deficient in p40 as well as mice treated with neutralizing anti-p40 mAbs have a substantially reduced skin inflammation upon Aldara treatment. As anti-p40 Abs target both IL-12 and IL-23, we hypothesed, that IL-12 might have a protective role in psoriatic plaque formation. We found that skin inflammation was highly increased in mice lacking IL-12 (IL-12p35-/-) or when IL-12 signalling (IL-12Rb2-/-) was disrupted. Local injection of IL-12Fc significantly reduced skin inflammation that was corroborated by reduced leucocytes infiltrations as well diminished IL-17A expression in the skin. IL-12 stimulated CD27- γδ T cells secrete lower levels of IL-17A and F compared to their unstimulated controls suggesting direct effect of IL-12 on γδ T cells. Taken together, our findings suggest a protective role of IL-12 in psoriatic inflammation and support the need of introducing more specific treatment targeting the IL-23/IL-17 axis.
TLR2 initiates intestinal ischemia/reperfusion induced tissue damage (P4003)
Authors: Fleming Sherry , Pope Michael 
Published: January 2023

Abstract
Reperfusion (the return of blood flow) significantly magnifies ischemia (lack of blood flow) induced tissue damage in multiple clinical conditions including trauma and hemorrhage. During reperfusion, naturally occurring antibodies recognize endogenous damage-associated molecular patterns (DAMP), followed by an excessive complement activation, neutrophil infiltration and inflammatory response which frequently results in an excessive systemic inflammatory response which may lead to death. TLRs recognize DAMP and TLR4 is required for intestinal ischemia-reperfusion (IR). As TLR2 has been proposed to be the receptor for at least one DAMP, the serum protein, β2-glycoprotein I (β2-GPI) which is critical in intestinal ischemia reperfusion (IR), we hypothesized that IR-induced intestinal damage requires TLR2 for subsequent inflammation and tissue damage. Using TLR2-/- mice, we demonstrate that TLR2 is required for excessive IR-induced complement activation and pro-inflammatory cytokine production. TLR2-/- mice not only lacked the appropriate antibody repertoire to induce intestinal IR but treatment with wildtype antibodies was not sufficient to induce tissue damage or inflammation. Compared to wildtype mice, TLR2-/- mice have increased serum β2-GPI but β2-GPI is not deposited on ischemic intestinal tissue. Our data suggest that TLR2 interacts with β2-GPI and is required for neo-antigen expression and initiation of the systemic inflammatory response during intestinal IR.
Protective role of anti-viral human defensins during acute HIV infection (P4049)
Authors: Corleis Bjorn , Gostic William , Kwon Douglas 
Published: January 2023

Abstract
Background Human defensins are small cationic peptides with anti-bacterial and anti-viral activity. Beta defensins are expressed by epithelial cells and innate immune cells in tissue and circulating leukocytes, respectively. They are part of the first line of innate immune defense against invading pathogens at mucosal sites. Methods We investigated anti-HIV activity and production of beta defensins in intestinal mucosal biopsies and PBMCs from individuals with chronic untreated HIV, immunologically controlled HIV, acute HIV and HIV uninfected individuals using ELISA, immunohistochemistry, quantitative PCR and viral inhibition assays. Results Human beta defensin expression in PBMCs was found exclusively in classical monocytes whereas epithelial cells were found to be the main source in the intestinal tract. Expression of human beta defensins was not altered in gut tissue or PBMCs from HIV progressors and controller compared to HIV negative control sample. However, we observed increased expression in PBMCs from HIV acute patient samples. Further, recombinant human beta defensins showed anti-HIV activity in vitro. Conclusions Our data suggest that beta defensins have a direct effect on HIV and might act as an intrinsic antiviral factor early during HIV infection. Specific delivery of recombinant defensins might be a powerful tool to reduce viral burden during acute infection.
Severe pulmonary damages and high mortality rates shown in mice with combined burn and radiation injuries (P4005)
Authors: Nakamura Kiwamu , Cox Robert , Cornforth Michael , Herndon David , Kobayashi Makiko , Suzuki Fujio 
Published: January 2023

Abstract
Non-clinical human radiation exposure events are often coupled with burns, and victims with combined injuries are extremely susceptible to sepsis stemming from various local infections, as compared with that of patients either exposed to burns or radiation alone. In patients with combined injuries, infectious complications result in a high mortality rate, and Pseudomonas aeruginosa is a pathogen frequently isolated from these patients. In this study, the severities of burn wound infections with P. aeruginosa were studied in mice with combined radiation and burn injuries (CI-mice). All of the CI-mice infected with 10 CFU/mouse of P. aeruginosa died within 2 days of the infection, while mice with either injury alone survived more than 4 weeks after the same infection. Five CFU/mouse of P. aeruginosa was shown to be 1 LD50 in CI-mice, while 3 - 9 x 103 CFU/mouse of the pathogen were required to kill all of the mice with either injury alone. Severe pulmonary inflammation and decreased alveolar spaces were specifically observed in CI-mice. Lineage−CD45+CD34+CD44+CD49b+ cells appeared in association with combined injuries inhibited bactericidal activities of alveolar macrophages isolated from normal mice. Lineage−CD45+CD34+CD44+CD49b+ cells may play a role on the high susceptibility of CI-mice to P. aeruginosa burn wound infection.
IL17A receptor (IL17RA) signaling is important for protection against oral infection with Listeria monocytogenes (P4011)
Authors: Alam Mohammad , Kuo Jennifer , Babu Uma , Ganies Dennis , Pereira Marion , Williams Kristina 
Published: January 2023

Abstract
Foodborne Listeria monocytogenes (LM) causes serious illness & death every year in the US. Ingestion of LM can lead to septicemia, meningitis, & abortion. IL17 is secreted by T cells and regulates the production of CXC chemokines for monocyte and neutrophil recruitment to infected tissue. Foodborne LM infection occurs through the oral route, but mice are highly resistant to oral infection. Here, using a murinized LM strain, we explored the role of IL17RA signaling following oral LM infection. Mortality & body weight loss were compared after LM infection of C57BL/6 & IL17RA-KO mice. LM-specific proliferative responses of splenocytes isolated from infected mice were performed. Viable LM from liver & spleen tissue were enumerated. Neutrophil infiltration & inflammation were evaluated histologically. RT-PCR arrays were used to quantitate cytokine/chemokine mRNA expression in infected tissues. IL17RA-KO mice lost more body weight and died earlier following oral infection than infected WT mice. LM-Ag treated splenocytes from KO mice proliferated less vigorously than WT splenocytes. Tissues from infected IL17RA-KO mice had lower mRNA expression for IFN-γ, IL1-β & iNOS. Liver, spleen & gastric tissues from infected IL17RAKO mice showed increased necrotic tissue damage & increased LM burden. These results indicate that IL17RA signaling is important in host resistance to oral LM infection.