-
Brain, Behavior, and Immunity May 2024Fever plays an indispensable role in host defense processes and is used as a rapid index of infection severity. Unfortunately, there are also substantial individual...
Fever plays an indispensable role in host defense processes and is used as a rapid index of infection severity. Unfortunately, there are also substantial individual differences in fever reactions with biological sex, immunological history, and other demographic variables contributing to adverse outcomes of infection. The present series of studies were designed to test the hypothesis that a history of adolescent alcohol misuse may be a latent experiential variable that determines fever severity using polyinosinic:polycytidylic acid (poly I:C), a synthetic form of double-stranded RNA that mimics a viral challenge. Adult male and female Sprague Dawley rats were injected with 0 (saline) or 4 mg/kg poly I:C to first establish sex differences in fever sensitivity in Experiment 1 using implanted radiotelemetry devices for remote tracking. In Experiments 2 and 3, adolescent males and females were exposed to either water or ethanol (0 or 4 g/kg intragastrically, 3 days on, 2 days off, ∼P30-P50, 4 cycles/12 exposures total). After a period of abstinence, adult rats (∼P80-96) were then challenged with saline or poly I:C, and fever induction and maintenance were examined across a prolonged time course of 8 h using implanted probes. In Experiments 4 and 5, adult male and female subjects with a prior history of adolescent water or adolescent intermittent ethanol (AIE) were given saline or poly I:C, with tissue collected for protein and gene expression analysis at 5 h post-injection. Initial sex differences in fever sensitivity were minimal in response to the 4 mg/kg dose of poly I:C in ethanol-naïve rats. AIE exposed males injected with poly I:C showed a sensitized fever response as well as enhanced TLR3, IκBα, and IL-1β expression in the nucleus of the solitary tract. Other brain regions related to thermoregulation and peripheral organs such as spleen, liver, and blood showed generalized immune responses to poly I:C, with no differences evident between AIE and water-exposed males. In contrast, AIE did not affect responsiveness to poly I:C in females. Thus, the present findings suggest that adolescent binge drinking may produce sex-specific and long-lasting effects on fever reactivity to viral infection, with preliminary evidence suggesting that these effects may be due to centrally-mediated changes in fever regulation rather than peripheral immunological mechanisms.
PubMed: 38777284
DOI: 10.1016/j.bbi.2024.05.027 -
PloS One 2024It is amply demonstrated that cigarette smoke (CS) has a high impact on lung tumor progression worsening lung cancer patient prognosis and response to therapies....
BACKGROUND
It is amply demonstrated that cigarette smoke (CS) has a high impact on lung tumor progression worsening lung cancer patient prognosis and response to therapies. Alteration of immune cell types and functions in smokers' lungs have been strictly related with smoke detrimental effects. However, the role of CS in dictating an inflammatory or immunosuppressive lung microenvironment still needs to be elucidated. Here, we investigated the effect of in vitro exposure to cigarette smoke extract (CSE) focusing on macrophages.
METHODS
Immortalized murine macrophages RAW 264.7 cells were cultured in the presence of CS extract and their polarization has been assessed by Real-time PCR and cytofluorimetric analysis, viability has been assessed by SRB assay and 3D-cultures and activation by exposure to Poly(I:C). Moreover, interaction with Lewis lung carcinoma (LLC1) murine cell models in the presence of CS extract were analyzed by confocal microscopy.
RESULTS
Obtained results indicate that CS induces macrophages polarization towards the M2 phenotype and M2-phenotype macrophages are resistant to the CS toxic activity. Moreover, CS impairs TLR3-mediated M2-M1 phenotype shift thus contributing to the M2 enrichment in lung smokers.
CONCLUSIONS
These findings indicate that, in lung cancer microenvironment of smokers, CS can contribute to the M2-phenotype macrophages prevalence by different mechanisms, ultimately, driving an anti-inflammatory, likely immunosuppressive, microenvironment in lung cancer smokers.
Topics: Animals; Mice; Lung Neoplasms; Macrophages; Tumor Microenvironment; RAW 264.7 Cells; Cell Survival; Macrophage Activation; Smoke; Cell Polarity; Humans; Carcinoma, Lewis Lung
PubMed: 38776331
DOI: 10.1371/journal.pone.0303875 -
Development (Cambridge, England) May 2024In utero infection and maternal inflammation can adversely impact fetal brain development. Maternal systemic illness, even in the absence of direct fetal brain...
In utero infection and maternal inflammation can adversely impact fetal brain development. Maternal systemic illness, even in the absence of direct fetal brain infection, is associated with an increased risk of neuropsychiatric disorders in affected offspring. The cell types mediating the fetal brain response to maternal inflammation are largely unknown, hindering the development of novel treatment strategies. Here, we show that microglia, the resident phagocytes of the brain, highly express receptors for relevant pathogens and cytokines throughout embryonic development. Using a rodent maternal immune activation (MIA) model in which polyinosinic:polycytidylic acid is injected into pregnant mice, we demonstrate long-lasting transcriptional changes in fetal microglia that persist into postnatal life. We find that MIA induces widespread gene expression changes in neuronal and non-neuronal cells; importantly, these responses are abolished by selective genetic deletion of microglia, indicating that microglia are required for the transcriptional response of other cortical cell types to MIA. These findings demonstrate that microglia play a crucial durable role in the fetal response to maternal inflammation, and should be explored as potential therapeutic cell targets.
Topics: Animals; Microglia; Female; Pregnancy; Mice; Brain; Inflammation; Poly I-C; Fetus; Mice, Inbred C57BL; Gene Expression Regulation, Developmental; Neurons
PubMed: 38775708
DOI: 10.1242/dev.202252 -
Clinical, Cosmetic and Investigational... 2024Atopic dermatitis (AD) is a chronic, non-infectious inflammatory dermatosis. Chloroquine (CQ) has long been proven to possess anti-inflammatory properties.
INTRODUCTION
Atopic dermatitis (AD) is a chronic, non-infectious inflammatory dermatosis. Chloroquine (CQ) has long been proven to possess anti-inflammatory properties.
OBJECTIVE
This paper aims to investigate the impact of CQ on type 2 inflammatory response in MC903-induced AD mice.
METHODS
An AD mouse model was established via MC903 induction. After CQ treatment, AD mice were intraperitoneally injected with polyinosinic: polycyclic acid [poly (I:C)] or Nigericin. Dermatitis severity was scored, and the thickness of the left ear was measured. The pathological changes in mouse skin tissues were observed by H&E staining. The number of mast cells was counted via TB staining. The content of peripheral blood T-helper 2 (Th2) cells and levels of immunoglobulin E (IgE), thymic stromal-derived lymphopoietin (TSLP), interleukin (IL)-4, IL-13, interferon (IFN)-γ, IL-1β, and IL-18 were assessed by flow cytometry and ELISA. The levels of toll-like receptor 3 (TLR3), NLRP3, ASC, and cleaved caspase-1 proteins in skin tissues were determined by Western blot.
RESULTS
CQ treatment abated dermatitis severity and left ear thickness in AD mice, alleviated skin damage, reduced mast cell number, diminished IgE, TSLP, IL-4, and IL-13 levels, and peripheral blood Th2 cell content, with no significant changes in IFN-γ level. CQ alleviated type 2 inflammatory response in AD mice by inhibiting the activation of TLR3. CQ suppressed NLRP3 inflammasome activation. Activating TLR3/NLRP3 annulled CQ-mediated alleviation on type 2 inflammatory response in AD mice.
CONCLUSION
CQ alleviated type 2 inflammatory response in AD mice by inhibiting TLR3 activation and NLRP3 inflammasome activation.
PubMed: 38765196
DOI: 10.2147/CCID.S440308 -
Developmental and Comparative Immunology Aug 2024Toll-like receptors (TLRs) are pivotal pattern recognition receptors (PRRs) and key mediators of innate immunity. Despite the significance of channel catfish (Ictalurus...
Toll-like receptors (TLRs) are pivotal pattern recognition receptors (PRRs) and key mediators of innate immunity. Despite the significance of channel catfish (Ictalurus punctatus) in comparative immunology and aquaculture, its 20 TLR genes remain largely functionally uncharacterized. In this study, our aim was to determine the catfish TLR7 agonists, signaling potential, and cellular localization. Using a mammalian reporter system, we identified imiquimod and resiquimod, typical ssRNA analogs, as potent catfish TLR7 agonists. Notably, unlike grass carp TLR7, catfish TLR7 lacks the ability to respond to poly (I:C). Confocal microscopy revealed predominant catfish TLR7 expression in lysosomes, co-localizing with the endosomal chaperone protein, UNC93B1. Furthermore, imiquimod stimulation elicited robust IFNb transcription in peripheral blood leukocytes isolated from adult catfish. These findings underscore the conservation of TLR7 signaling in catfish, reminiscent of mammalian TLR7 responses. Our study sheds light on the functional aspects of catfish TLR7 and contributes to a better understanding of its role in immune defense mechanisms.
Topics: Animals; Imiquimod; Toll-Like Receptor 7; Imidazoles; Ictaluridae; Lysosomes; Fish Proteins; Immunity, Innate; Signal Transduction; Humans; Aminoquinolines; Poly I-C
PubMed: 38763479
DOI: 10.1016/j.dci.2024.105197 -
Biochemical and Biophysical Research... Jul 2024The RNA-binding protein PKR serves as a crucial antiviral innate immune factor that globally suppresses translation by sensing viral double-stranded RNA (dsRNA) and by...
The RNA-binding protein PKR serves as a crucial antiviral innate immune factor that globally suppresses translation by sensing viral double-stranded RNA (dsRNA) and by phosphorylating the translation initiation factor eIF2α. Recent findings have unveiled that single-stranded RNAs (ssRNAs), including in vitro transcribed (IVT) mRNA, can also bind to and activate PKR. However, the precise mechanism underlying PKR activation by ssRNAs, remains incompletely understood. Here, we developed a NanoLuc Binary Technology (NanoBiT)-based in vitro PKR dimerization assay to assess the impact of ssRNAs on PKR dimerization. Our findings demonstrate that, akin to double-stranded polyinosinic:polycytidylic acid (polyIC), an encephalomyocarditis virus (EMCV) RNA, as well as NanoLuc luciferase (Nluc) mRNA, can induce PKR dimerization. Conversely, homopolymeric RNA lacking secondary structure fails to promote PKR dimerization, underscoring the significance of secondary structure in this process. Furthermore, adenovirus VA RNA 1, another ssRNA, impedes PKR dimerization by competing with Nluc mRNA. Additionally, we observed structured ssRNAs capable of forming G-quadruplexes induce PKR dimerization. Collectively, our results indicate that ssRNAs have the ability to either induce or inhibit PKR dimerization, thus representing potential targets for the development of antiviral and anti-inflammatory agents.
Topics: eIF-2 Kinase; Humans; Protein Multimerization; RNA, Viral; Encephalomyocarditis virus; RNA, Double-Stranded; Poly I-C; Nucleic Acid Conformation
PubMed: 38761636
DOI: 10.1016/j.bbrc.2024.150103 -
Scandinavian Journal of Immunology May 2024The IFIH1 gene, encoding melanoma differentiation-associated protein 5 (MDA5), is an indispensable innate immune regulator involved in the early detection of viral...
The IFIH1 gene, encoding melanoma differentiation-associated protein 5 (MDA5), is an indispensable innate immune regulator involved in the early detection of viral infections. Previous studies described MDA5 dysregulation in weakened immunological responses, and increased susceptibility to microbial infections and autoimmune disorders. Monoallelic gain-of-function of the IFIH1 gene has been associated with multisystem disorders, namely Aicardi-Goutieres and Singleton-Merten syndromes, while biallelic loss causes immunodeficiency. In this study, nine patients suffering from recurrent infections, inflammatory diseases, severe COVID-19 or multisystem inflammatory syndrome in children (MIS-C) were identified with putative loss-of-function IFIH1 variants by whole-exome sequencing. All patients revealed signs of lymphopaenia and an increase in inflammatory markers, including CRP, amyloid A, ferritin and IL-6. One patient with a pathogenic homozygous variant c.2807+1G>A was the most severe case showing immunodeficiency and glomerulonephritis. The c.1641+1G>C variant was identified in the heterozygous state in patients suffering from periodic fever, COVID-19 or MIS-C, while the c.2016delA variant was identified in two patients with inflammatory bowel disease or MIS-C. There was a significant association between IFIH1 monoallelic loss of function and susceptibility to infections in males. Expression analysis showed that PBMCs of one patient with a c.2016delA variant had a significant decrease in ISG15, IFNA and IFNG transcript levels, compared to normal PBMCs, upon stimulation with Poly(I:C), suggesting that MDA5 receptor truncation disrupts the immune response. Our findings accentuate the implication of rare monogenic IFIH1 loss-of-function variants in altering the immune response, and severely predisposing patients to inflammatory and infectious diseases, including SARS-CoV-2-related disorders.
PubMed: 38757311
DOI: 10.1111/sji.13373 -
Behavioural Brain Research Jul 2024Epidemiological evidence has shown that maternal infection is a notable risk factor for developmental psychiatric disorders. Animal models have corroborated this link...
Epidemiological evidence has shown that maternal infection is a notable risk factor for developmental psychiatric disorders. Animal models have corroborated this link and demonstrated that maternal immune activation (MIA) induces long-term behavioural deficits and neuroimmunological responses to subsequent immune stress in offspring. However, it is unclear whether MIA offspring are more sensitive or more tolerant to immunological challenges from postnatal infections. Pregnant mice were weighed and injected with a single dose of polyinosinic-polycytidylic acid (poly I:C) or saline at gestational day 9.5, and their male offspring were exposed to poly I:C or saline again during adolescence, adulthood, and middle life. After a two-week recovery from the last exposure to poly I:C, the mice underwent behavioural and neuroendophenotypic evaluations. Finally, the mice were sacrificed, and the expression levels of inflammatory factors and the activation levels of glial cells in the cerebral cortex and hippocampus were evaluated. We found MIA mice have lifelong behavioural deficits and glial activation abnormalities. Postpartum infection exposure at different ages has different consequences. Adolescent and middle life exposure prevents sensorimotor gating deficiency, but adult exposure leads to increased sensitivity to MK-801. Moreover, MIA imposed a lasting impact on the neuroimmune profile, resulting in an enhanced cytokine-associated response and diminished microglial reactivity to postnatal infection. Our results reveal an intricate interplay between prenatal and postpartum infection in neuropsychiatric phenotypes, which identify potential windows where preventive or mitigating measures could be applied.
Topics: Animals; Female; Pregnancy; Prenatal Exposure Delayed Effects; Poly I-C; Mice; Male; Disease Models, Animal; Behavior, Animal; Hippocampus; Postpartum Period; Mice, Inbred C57BL; Phenotype; Cerebral Cortex; Cytokines; Sensory Gating
PubMed: 38754789
DOI: 10.1016/j.bbr.2024.115049 -
ACS Pharmacology & Translational Science May 2024Polyriboinosinic acid-polyribocytidylic acid (Poly I:C) serves as a synthetic mimic of viral double-stranded dsRNA, capable of inducing apoptosis in numerous cancer...
Polyriboinosinic acid-polyribocytidylic acid (Poly I:C) serves as a synthetic mimic of viral double-stranded dsRNA, capable of inducing apoptosis in numerous cancer cells. Despite its potential, therapeutic benefits, the application of Poly I:C has been hindered by concerns regarding toxicity, stability, enzymatic degradation, and undue immune stimulation, leading to autoimmune disorders. To address these challenges, encapsulation of antitumor drugs within delivery systems such as cationic liposomes is often employed to enhance their efficacy while minimizing dosages. In this study, we investigated the potential of cationic liposomes to deliver Poly I:C into the Head and Neck 12 (HN12) cell line to induce apoptosis in the carcinoma cells and tumor model. Cationic liposomes made by the hydrodynamic focusing method surpass traditional methods by offering a continuous flow-based approach for encapsulating genes, which is ideal for efficient tumor delivery. DOTAP liposomes efficiently bind Poly I:C, confirmed by transmission electron microscopy images displaying their spherical morphology. Liposomes are easily endocytosed in HN12 cells, suggesting their potential for therapeutic gene and drug delivery in head and neck squamous carcinoma cells. Activation of apoptotic pathways involving MDA5, RIG-I, and TLR3 is evidenced by upregulated caspase-3, caspase-8, and IRF3 genes upon endocytosis of Poly(I:C)-encapsulated liposomes. Therapeutic evaluations revealed significant inhibition of tumor growth with Poly I:C liposomes, indicating the possibility of MDA5, RIG-I, and TLR3-induced apoptosis pathways via Poly I:C liposomes in HN12 xenografts in J:NU mouse models. Comparative histological analysis underscores enhanced cell death with Poly I:C liposomes, warranting further investigation into the precise mechanisms of apoptosis and inflammatory cytokine response in murine models for future research.
PubMed: 38751634
DOI: 10.1021/acsptsci.4c00121 -
Fish & Shellfish Immunology Jul 2024The interleukin-12 (IL-12) family is a class of heterodimeric cytokines that play crucial roles in pro-inflammatory and pro-stimulatory responses. Although some IL-12...
The interleukin-12 (IL-12) family is a class of heterodimeric cytokines that play crucial roles in pro-inflammatory and pro-stimulatory responses. Although some IL-12 and IL-23 paralogues have been found in fish, their functional activity in fish remains poorly understood. In this study, Pf_IL-12p35a/b, Pf_IL-23p19 and Pf_IL-12p40a/b/c genes were cloned from yellow catfish (Pelteobagrus fulvidraco), four α-helices were found in Pf_IL-12p35a/b and Pf_IL-23p19. The transcripts of these six genes were relatively high in mucus and immune tissues of healthy individuals, and in gill leukocytes. Following Edwardsiella ictaluri infection, Pf_IL-12p35a/b and Pf_IL-23p19 mRNAs were induced in brain and kidney (or head kidney), Pf_IL-12p40a mRNA was induced in gill, and Pf_IL-12p40b/c mRNAs were induced in brain and liver (or skin). The mRNA expression of these genes in PBLs was induced by phytohaemagglutinin (PHA) and polyinosinic-polycytidylic acid (poly I:C), while lipopolysaccharides (LPS) induced the mRNA expression of Pf_IL-12p35a and Pf_IL-12p40b/c in PBLs. After stimulation with recombinant (r) Pf_IL-12 and rPf_IL-23 subunit proteins, either alone or in combination, mRNA expression patterns of genes related to T helper cell development exhibited distinct differences. The results suggest that Pf_IL-12 and Pf_IL-23 subunits may play important roles in regulating immune responses to pathogens and T helper cell development.
Topics: Animals; Catfishes; Fish Proteins; Enterobacteriaceae Infections; Fish Diseases; Gene Expression Regulation; Interleukin-12 Subunit p40; Gene Expression Profiling; Immunity, Innate; Edwardsiella ictaluri; Interleukin-12 Subunit p35; Phylogeny; Amino Acid Sequence; Sequence Alignment; Interleukin-23 Subunit p19; Poly I-C
PubMed: 38750705
DOI: 10.1016/j.fsi.2024.109623