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At least 217 records · Page 12

Zika virus dynamics: Effects of inoculum dose, the innate immune response and viral interference

Experimental Zika virus infection in non-human primates results in acute viral load dynamics that can be well-described by mathematical models. The inoculum dose that would be received in a natural infection setting is likely lower than the experimental infections and how this difference affects the viral dynamics and immune response is unclear. Here we study a dataset of experimental infection of non-human primates with a range of doses of Zika virus. We develop new models of infection incorporating both an innate immune response and viral interference with that response. We find that such a model explains the data better than models with no interaction between virus and the immune response. We also find that larger inoculum doses lead to faster dynamics of infection, but approximately the same total amount of viral production.

59 BASIC BIOLOGICAL SCIENCES↗

Both the intratumoral immune and microbial microenvironment are linked to recurrence in human colon cancer: results from a prospective, multicenter nodal ultrastaging trial

Background: Colon cancer (CC) is the third most common cancer diagnosed in the United States and the incidence has been rising among young adults. We and others have shown a relationship between the immune infiltrate and prognosis, with improved disease-free survival (DFS) associated with a higher expression of CD8+ T cells. Additionally, numerous studies indicate the gut microbiota is linked to colon cancer and clinical outcomes. Therefore, we hypothesized a microbial signature might be associated with both the intratumoral immune cells as well as DFS. Results: Ninety-one patients were randomly selected from a prospective NCI-sponsored multicenter trial evaluating ultrastaging in CC to investigate the intratumoral microbiota by 16S rRNA gene amplicon sequencing. Operational taxonomic units (OTUs) were grouped by 97% sequence similarity. A series of clinical, immunohistochemical, and microbiota-related data were first evaluated by univariable cox regression to determine candidate variables associated with DFS. DFS was influenced by three parameters: N-stage, CD8+ labeling, and one microbiota principal component by multivariate analysis (MVA). Not only were the microbiota and CD8 significant contributors to the DFS model, but they were also significantly associated with each other. Alpha diversity showed an inverse correlation to CD8+ T cells (p=0.010, R=-0.278) and beta diversity showed an association with the CD8+ T cells (u-UniFrac p=0.026, w-UniFrac p=0.034). Further analysis at the OTU level with false discovery correction revealed one OTU, OTU_104, belonging to the order Clostridiales to be associated with increased recurrence (HR 1.21, CI 1.08 to 1.36). This OTU_104 was then found to be inversely correlated to CD8+ T cells (p=0.031, R=-0.35). Conclusions: This study is the first to demonstrate an association between the intratumoral microbiota, CD8+ T cells, and recurrence in CC. An increased relative abundance of a specific OTU_104 was inversely associated with CD8+ T cells and increased CC recurrence. The link between this microbe, CD8+ T cells and DFS has not been previously shown. Further studies are warranted to examine the role of infiltrating immune cells and the microbiota on colon cancer.

colon cancer↗

Acid external and internal environment exchange the Oreochromis niloticus tissue immune gene expression compared to the mouse macrophage polarization model

The water environment plays an important role in animal physiology. In this study, we sought to evaluate the effect of the acid environment on the Oreochromis niloticus (Nile tilapia) internal microenvironment immune response compare to the mouse macrophage model (J77A.1). The acid environment treated mouse macrophage J774A.1 model have shown that acidic treatment is able to polarize macrophages into M2-like macrophages via an increase in Ym1, Tgm2, Arg1, Fizz1, and IL-10 expression. Metabolic analysis of mouse macrophages (J774A.1) at pH 2 vs. pH 7 and pH 4 vs. pH 7 have been shown to promote the expression of intracellular acetylcholine, choline, prochlorperazine, L-leucine, and bisphenol A,2-amino-3-methylimidazo[4,5-f] quinolone metabolites in the M2-like macrophage. Immune gene expression of the O. niloticus spleen and liver treated at pH 2, 4, and 7 was shown to reduce TNF-α, IL-1 β, IL-8, and IL-12 expression compared to pH 7 treatment. Immune gene was induced in O. niloticus following culture at pH 5, 6, and 7 fresh water environment. Taken together, we found that the acid internal environment polarizes tissues into an M2 macrophage developmental microenvironment. However, if the external environment is acid, tissues are exposed to an M1 macrophage developmental microenvironment.

59 BASIC BIOLOGICAL SCIENCES↗

The immune system in space and microgravity

Space flight and models that created conditions similar to those that occur during space flight have been shown to affect a variety of immunological responses. These have primarily been cell-mediated immune responses including leukocyte proliferation, cytokine production, and leukocyte subset distribution. The mechanisms and biomedical consequences of these changes remain to be established. Among the possible causes of space flight-induced alterations in immune responses are exposure to microgravity, exposure to stress, exposure to radiation, and many more as yet undetermined causes. This review chronicles the known effects of space flight on the immune system and explores the possible role of stress in contributing to these changes.

unmanned↗

Changes in the immune system during and after spaceflight

The results of immunological analyses before, during and after spaceflight, have established the fact that spaceflight can result in a blunting of the immune mechanisms of human crew members and animal test species. There is some evidence that the immune function changes in short-term flights resemble those occurring after acute stress, while the changes during long-term flights resemble those caused by chronic stress. In addition, this blunting of the immune function occurs concomitant with a relative increase in potentially infectious microorganisms in the space cabin environment. This combination of events results in an increased probability of inflight infectious events. The realization of this probability has been shown to be partially negated by the judicious use of a preflight health stabilization program and other operational countermeasures. The continuation of these countermeasures, as well as microbial and immunological monitoring, are recommended for continued spaceflight safety.

manned↗

Physical Model of Immune Inspired Computing

Artificial Immune System is a rapidly growing field of information processing and computing based upon immune inspired paradigns of nonlinear dynamics. This paper introduces stochastic models which mimic the phenomenology of basic functions of immune systems such as self-nonself discrimination, self-repair, predator-prey pursuit, and reproduction.

Immune↗

Thoracic Imaging of Solid Tumor Patients Treated with Immune Checkpoint Inhibitors

Purpose of Review: Immune checkpoint inhibitors harness the patient’s own immune system to fight cancer. They are now approved for treating a number of solid malignancies, with more agents and indications expected in the coming months and years. Because of their unique mechanism of action, these agents may lead to unusual imaging appearances. Recent Findings: Rare patients may experience pseudoprogression, whereby tumors may initially increase in size or number despite response to therapy. Many patients will experience autoimmune side effects including pneumonitis, which may lead to respiratory compromise and will necessitate cessation of therapy. Occasionally pneumonitis or a sarcoid-like reaction can mimic metastatic disease. Summary: It is imperative that radiologists be aware of these unusual imaging manifestations in patients on immunotherapy so that they are able to assist oncologists in appropriately treating these patients. In particular, we urge caution in interpreting new or enlarging lesions, since these may not always mean progression of disease. Additionally, radiologists should look out for potential immune-related side effects of these therapies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Intestinal microbiota and immune related genes in sea cucumber (Apostichopus japonicus) response to dietary β-glucan supplementation

β-glucan is a prebiotic well known for its beneficial outcomes on sea cucumber health through modifying the host intestinal microbiota. High-throughput sequencing techniques provide an opportunity for the identification and characterization of microbes. In this study, we investigated the intestinal microbial community composition, interaction among species, and intestinal immune genes in sea cucumber fed with diet supplemented with or without β-glucan supplementation. The results show that the intestinal dominant classes in the control group are Flavobacteriia, Gammaproteobacteria, and Alphaproteobacteria, whereas Alphaproteobacteria, Flavobacteriia, and Verrucomicrobiae are enriched in the β-glucan group. Dietary β-glucan supplementation promoted the proliferation of the family Rhodobacteraceae of the Alphaproteobacteria class and the family Verrucomicrobiaceae of the Verrucomicrobiae class and reduced the relative abundance of the family Flavobacteriaceae of Flavobacteria class. The ecological network analysis suggests that dietary β-glucan supplementation can alter the network interactions among different microbial functional groups by changing the microbial community composition and topological roles of the OTUs in the ecological network. Dietary β-glucan supplementation has a positive impact on immune responses of the intestine of sea cucumber by activating NF-κB signaling pathway, probably through modulating the balance of intestinal microbiota. - Highlights: • Dietary β-glucan supplementation increases the abundance of Rhodobacteraceae and Verrucomicrobiaceae in the intestine. • Dietary β-glucan supplementation changes the topological roles of OTUs in the ecological network. • Dietary β-glucan supplementation has a positive impact on the immune response of intestine of sea cucumber.

60 APPLIED LIFE SCIENCES↗

Induction of immune-related gene expression by seminal exosomes in the porcine endometrium

Highlights: • Exosomes are present in sperm-rich fraction of porcine seminal plasma (SP). • Exosomes present in SP regulate immune-related genes in the porcine uterus. • Seminal exosomes may pave the way for sperm and fertilized egg transport. Seminal plasma (SP) is considered as a vehicle to carry sperm into female reproductive tract, of which functions have not been completely understood. This study aimed to identify the function of seminal exosomes on porcine endometrium. Exosomes were isolated from the sperm-rich fraction of boar semen and were confirmed by the expression of exosome marker HSP70 and size distribution using nano-sight tracking analysis. Porcine endometrial epithelial cells (EECs) were then treated with seminal exosomes, and RNA extracted were subjected to global expression analysis. Transcripts related to “immune response”, “inflammatory response” and their associated signaling pathways were up-regulated in EECs treated with seminal exosome, whereas those associated with “steroid biosynthesis”, “metabolic pathways” and “T cell differentiation” were down-regulated. The decrease in PMVK, SC5D, INSIG1, HSD17B7, NSDHL, HMGCR, SQLE and FDFT1, and increase in CCL20, TNFSF15, AMCFII, CXCL2 and CXCL8 were also found in the endometrium from the naturally mated pigs. Moreover, changes in exosome-induced CYP24A1, EBP, CCL20, AMCFII and IL1A expression were not regulated by the exosome removed SP. These observations indicated that exosomes present in SP are involved in the immune-related gene regulation in the uterus, which could pave the passage for sperm and possibly fertilized eggs.

60 APPLIED LIFE SCIENCES↗

Mechanical stress to Drosophila larvae stimulates a cellular immune response through the JAK/STAT signaling pathway

Acute inflammation can cause serious tissue damage and disease in physiologically-challenged organisms. The precise mechanisms leading to these detrimental effects remain to be determined. In this study, we utilize a reproducible means to induce cellular immune activity in Drosophila larvae in response to mechanical stress. That is, forceps squeeze-administered stress induces lamellocytes, a defensive hemocyte type that normally appears in response to wasp infestation of larvae. The posterior signaling center (PSC) is a cellular microenvironment in the larval hematopoietic lymph gland that is vital for lamellocyte induction upon parasitoid attack. However, we found the PSC was not required for mechanical stress-induced lamellocyte production. In addition, we observed that mechanical injury caused a systemic expression of Unpaired3. This cytokine is both necessary and sufficient to activate the cellular immune response to the imposed stress. These findings provide new insights into the communication between injured tissues and immune system induction, using stress-challenged Drosophila larvae as a tractable model system.

60 APPLIED LIFE SCIENCES↗

Immune inhibitory receptor LILRB2 is critical for the endometrial cancer progression

Although leukocyte immunoglobulin-like receptor subfamily B member 2 (LILRB2) is known as an immune inhibitory receptor to suppress the immune system, its function in cancer development remains largely unknown. Herein, we provide the first body of information showing that LILRB2 is highly expressed in the endometrial cancer. More importantly, the expression levels of LILRB2 are inversely correlated with the overall patients’ survival. Knockdown of LILRB2 results in a dramatic decrease in the proliferation, colony formation and migration in several endometrial cancer cell lines in vitro. Furthermore, in vivo xenograft experiments reveal a notable reduction of tumor cell growth. Mechanistically, LILRB2 enhances the SHP2/CaMK1/CREB signaling pathways to support the expansion and migration of the endometrial cancer cells. These findings unravel an unexpected role of LILRB2 in solid cancers except for its canonical role in immune surveillance, which may serve as a potential endometrial stem cell marker and may benefit the development of novel strategies for the treatment of endometrial cancers.

60 APPLIED LIFE SCIENCES↗

Far upstream element-binding protein 1 is up-regulated in pancreatic cancer and modulates immune response by increasing programmed death ligand 1

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. So far, almost all treatments are almost ineffective for pancreatic cancer. Thus, there is an urgent need to develop novel therapeutics for pancreatic cancer treatment. Immune checkpoints blockade therapies, including anti-PD-L1 and anti-PD-1, show promising anti-tumor efficacy for a various type of solid tumors. However, pancreatic cancer is disappointed for anti-PD-L1 therapy alone. The expression level of PD-L1 is considered as one of determinant of checkpoint immunotherapy efficacy. The far upstream element-binding protein 1 (FUBP1) is an important transactivator of c-Myc proto-oncogene. Here, we demonstrate that FUBP1 is overexpressed in pancreatic cancer and associated with poor prognosis. Moreover, we show that FUBP1 promotes tumor cell proliferation and migration and regulates the cancer cell immunity by increasing the PD-L1 expression mediated by Myc in pancreatic cancer cells. Taken together, these findings uncover important aspects of the function of FUBP1 in cancer immunity and elucidated the specific mechanism regulating PD-L1 expression. Targeting FUBP1 may be a novel therapeutic strategy to overcome the immunotherapy resistance in pancreatic cancer.

60 APPLIED LIFE SCIENCES↗

Overcoming Steric Restrictions of VRC01 HIV-1 Neutralizing Antibodies through Immunization

Broadly HIV-1 neutralizing VRC01 class antibodies target the CD4-binding site of Env. They are derived from VH1-2*02 antibody heavy chains paired with rare light chains expressing 5-amino acid-long CDRL3s. They have been isolated from infected subjects but have not yet been elicited by immunization. Env-derived immunogens capable of binding the germline forms of VRC01 B cell receptors on naive B cells have been designed and evaluated in knockin mice. However, the elicited antibodies cannot bypass glycans present on the conserved position N276 of Env, which restricts access to the CD4-binding site. Efforts to guide the appropriate maturation of these antibodies by sequential immunization have not yet been successful. Here, we report on a two-step immunization scheme that leads to the maturation of VRC01-like antibodies capable of accommodating the N276 glycan and displaying autologous tier 2 neutralizing activities. Our results are relevant to clinical trials aiming to elicit VRC01 antibodies.

59 BASIC BIOLOGICAL SCIENCES↗

Engineering the AAV capsid to evade immune responses

Gene therapy is progressively emerging as a promising and powerful therapeutic modality, and adeno-associated virus (AAV) is a major delivery vehicle for such therapies. Among the most significant challenges that limit AAV's utility, however, is the immune response it elicits. Antibodies elicited by prior exposure to natural virus or vector can bind to an AAV vector, preventing it from entering the cell. Furthermore, even if AAV manages to infect a target cell, these cells can then be attenuated by lymphocytes. Improvements in our understanding of how the immune system responds to AAV have guided engineering of the capsid to reduce those responses, yielding capsid variants that are much stealthier and more effective. This review summarizes recent advances in understanding the immune response to AAV as well as highlights engineering methods that enhance AAV's potential as a gene therapy vector.

59 BASIC BIOLOGICAL SCIENCES↗

Prospective Clinical Investigation of the Efficacy of Combination Radiation Therapy With Immune Checkpoint Inhibition

Immune checkpoint inhibitors (ICIs) lead to durable responses in a subset of patients with cancer, but most patients do not respond to ICI, prompting interest in combining immunotherapy with other therapeutic regimens. Preclinical evidence supports the potential for therapeutic synergy between immunotherapy and radiation therapy through modulation of the tumor microenvironment and antitumor immune responses. Local therapy also has the potential to overcome localized sites of relative immune suppression and resistance. Prospective clinical trials have been initiated to test these hypotheses in the clinic as well as to investigate the toxicities and adverse events associated with combination immunotherapy and radiation therapy. In this review, we discuss the emerging results from prospective clinical trials of combination immunotherapy and radiation therapy, the safety and efficacy of their combination, concordance with preclinical and retrospective data, and some of the remaining open questions to be addressed by future clinical trials.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Thiol dependent NF-κB suppression and inhibition of T-cell mediated adaptive immune responses by a naturally occurring steroidal lactone Withaferin A

Withaferin A (WA), a steroidal lactone isolated from ayurvedic medicinal plant Withania somnifera, was shown to inhibit tumor growth by inducing oxidative stress and suppressing NF-κB pathway. However, its effect on T-cell mediated adaptive immune responses and the underlying mechanism has not been investigated. Since both T-cell responses and NF-κB pathway are known to be redox sensitive, the present study was undertaken to elucidate the effect of WA on adaptive immune responses in vitro and in vivo. WA inhibited mitogen induced T-cell and B-cell proliferation in vitro without inducing any cell death. It inhibited upregulation of T-cell (CD25, CD69, CD71 and CD54) and B-cell (CD80, CD86 and MHC-II) activation markers and secretion of Th1 and Th2 cytokines. WA induced oxidative stress by increasing the basal ROS levels and the immunosuppressive effects of WA were abrogated only by thiol anti-oxidants. The redox modulatory effects of WA in T-cells were attributed to its ability to directly interact with free thiols. WA inhibited NF-κB nuclear translocation in lymphocytes and prevented the direct binding of nuclear NF-κB to its consensus sequence. MALDI-TOF analysis using a synthetic NF-κB-p50 peptide containing Cys-62 residue suggested that WA can modify the cysteine residue of NF-κB. The pharmacokinetic studies for WA were also carried out and in vivo efficacy of WA was studied using mouse model of Graft-versus-host disease. In conclusion, WA is a potent inhibitor of T-cell responses and acts via a novel thiol dependent mechanism and inhibition of NF-κB pathway. - Highlights:: • Withaferin A (WA) inhibited T-cell and B-cell mediated immune responses. • WA increased basal ROS levels in lymphocytes. • WA directly interacted with GSH as studied using spectrophotometry and HPLC. • WA inhibited NF-κB nuclear translocation and binding of nuclear NF-κB to DNA. • WA inhibited induction of the graft-versus-host disease in mice.

60 APPLIED LIFE SCIENCES↗

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10–10,000 pg/kg body weight/day; PCB 153: 0.09–1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes. - Highlights: • Early life exposure to TCDD affects programming of energy and immune homeostasis. • Early life exposure to PCB 153 affects programming of energy homeostasis. • Both compounds act sex-specifically. • Lowest derived BMDLs for both TCDD and PCB 153 are not lower than current tolerable daily intakes.

60 APPLIED LIFE SCIENCES↗

Genistein prevention of hyperglycemia and improvement of glucose tolerance in adult non-obese diabetic mice are associated with alterations of gut microbiome and immune homeostasis

Although studies have linked soy phytoestrogen 4,7,4-trihydroxyisoflavone genistein (GEN) to reduced type 1 diabetes (T1D) risk, the mechanism of dietary GEN on T1D remains unknown. In our studies, adult non-obese diabetic (NOD) mouse model was employed to investigate the effects of GEN exposure on blood glucose level (BGL), glucose tolerance, gut microbiome, and immune responses. Adult male and female NOD mice were fed with either soy-based or casein-based diet, and received GEN at 20 mg/kg body weight by gavage daily. The BGL and immune responses (represented by serum antibodies, cytokines and chemokines, and histopathology) were monitored, while the fecal gut microbiome was sequenced for 16S ribosomal RNA to reveal any alterations in gut microbial communities. A significantly reduced BGL was found in NOD males fed with soy-based diet on day 98 after initial dosing, and an improved glucose tolerance was observed on both diets. In addition, an anti-inflammatory response (suggested by reduced IgG{sub 2b} and cytokine/chemokine levels, and alterations in the microbial taxonomy) was accompanied by an altered β-diversity in gut microbial species. Among the NOD females exposed to GEN, a later onset of T1D was observed. However, the profiles of gut microbiome, antibodies and cytokines/chemokines were all indicative of pro-inflammation. This study demonstrated an association among GEN exposure, gut microbiome alteration, and immune homeostasis in NOD males. Although the mechanisms underlying the protective effects of GEN in NOD mice need to be explored further, the current study suggested a GEN-induced sex-specific effect in inflammatory status and gut microbiome. - Highlights: • GEN reduces blood glucose level and improves glucose tolerance in NOD males. • GEN delayed type 1 diabetes onset in NOD females. • GEN produces a perturbed gut microbiota in both NOD males and females. • GEN produces anti-inflammatory responses in NOD males. • GEN produces pro-inflammatory responses in NOD females.

60 APPLIED LIFE SCIENCES↗