Early Stages Of Infection Research Articles

A generic cell-based biosensor converts bacterial infection signals into chemoattractants for immune cells.

Bacterial infections are a major challenge to human health. Although various potent antibiotics have emerged in the last decades, current challenges arise from an increasing number of multi-drug-resistant species. Infections associated with implants represent a particular challenge since they are usually diagnosed at an advanced state, and are difficult to treat with antibiotics due to the formation of protecting biofilms. In this study, we designed and explored a synthetic biology-inspired, cell-based bio-sensor/actor for the detection and counteraction of bacterial infections. The system is generic as it senses diverse types of infections and acts by enhancement of the endogenous immune system. The strategy is based on genetically engineered sensor/actor cells that can sense type I interferons (IFNs), which are released by immune cells at the early stages of infections. IFN signalling activates a synthetic circuit to induce reporter genes with a sensitivity of only 5 pg/ml of IFN and leads to a therapeutic protein output of 100ng/ml, resulting in theranostic cells that visualize and fight infections. Robustness and resilience were achieved by the implementation of a positive feedback loop. We show that diverse gram-positive and gram-negative implant-associated pathogenic bacteria activate the cascade in co-culture systems in a dose-dependent manner. Finally, we show that this system can be used to secrete chemoattractants facilitating the infiltration of immune cells in response to bacterial triggers. Together, the system is not only universal to bacterial infections but at the same time hypersensitive allowing the sensing of infections at initial stages.

Footprints of innate immune activity during HIV-1 reservoir cell evolution in early-treated infection.

Antiretroviral treatment (ART) initiation during the early stages of HIV-1 infection is associated with a higher probability of maintaining drug-free viral control during subsequent treatment interruptions, for reasons that remain unclear. Using samples from a randomized-controlled human clinical trial evaluating therapeutic HIV-1 vaccines, we here show that early ART commencement is frequently associated with accelerated and efficient selection of genome-intact HIV-1 proviruses in repressive chromatin locations during the first year after treatment initiation. This selection process was unaffected by vaccine-induced HIV-1-specific T cell responses. Single-cell proteogenomic profiling demonstrated that cells harboring intact HIV-1 displayed a discrete phenotypic signature of immune selection by innate immune responses, characterized by a slight but significant upregulation of HLA-C, HLA-G, the IL-10 receptor, and other markers involved in innate immune regulation. Together, these results suggest an accelerated immune selection of viral reservoir cells during early-treated HIV-1 infection that seems at least partially driven by innate immune responses.

Time-Course Transcriptome Analysis Reveals Distinct Transcriptional Regulatory Networks in Resistant and Susceptible Grapevine Genotypes in Response to White Rot

Grapevine (Vitis vinifera L.) is a globally significant economic crop. However, its widely cultivated varieties are highly susceptible to white rot disease. To elucidate the mechanisms of resistance in grapevine against this disease, we utilized time-ordered gene co-expression network (TO-GCN) analysis to investigate the molecular responses in the grapevine varieties ‘Guifeimeigui’ (GF) and ‘Red Globe’ (RG). An assessment of their resistance demonstrated that GF is highly resistant to white rot, whereas RG is highly susceptible. We conducted transcriptome sequencing and a TO-GCN analysis on leaf samples from GF and RG at seven time points post-infection. Although a significant portion of the differentially expressed genes related to disease resistance were shared between GF and RG, the GF variety rapidly activated its defense mechanisms through the regulation of transcription factors during the early stages of infection. Notably, the gene VvLOX3, which is a key enzyme in the jasmonic acid biosynthetic pathway, was significantly upregulated in GF. Its upstream regulator, Vitvi08g01752, encoding a HD-ZIP family transcription factor, was identified through TO-GCN and yeast one-hybrid analyses. This study provides new molecular insights into the mechanisms of grapevine disease resistance and offers a foundation for breeding strategies aimed at enhancing resistance.

Identification and Functional Analysis of Git3 G Protein-Coupled Receptors in Ganoderma boninense PER71

G protein-coupled receptors (GPCRs) are integral components of eukaryotic heterotrimeric G proteins, playing crucial roles in detecting extracellular signals and initiating the activity of signaling proteins within cells to activate cellular responses to these signals. The objectives of this study are to identify and characterize the function of Git3, a Class III GPCR protein, in the oil palm pathogen Ganoderma boninense. To identify the potential genes encoded for GPCR in this fungus, intensive data mining on the genome and transcriptome data has been carried out. A total of six classes of GPCRs have been identified. These include Class II pheromone detectors, Class III carbon detectors, Class IV nitrogen detectors, Class VII proteins similar to glycosyltransferase, Class VIII proteins similar to hemolysin, and Class X protein receptors. Among these, the Class III protein Git3, postulated to be involved in glucose sensing and fungal pathogenicity, was selected for gene knockdown using RNA interference (RNAi). A plasmid, designated pUChph-GIT3, was constructed, to target git3 silencing by incorporating a hygromycin resistance gene cassette and antisense sequences of git3. Transformation of G. boninense PER71 with pUChph-GIT3 produced five potential Δgit3 gene-silenced mutants. PCR analysis confirmed the integration of the RNAi expression cassette into the fungal genome. Quantitative PCR (qPCR) analysis revealed significant reductions in git3 expression in three G. boninense mutants, M42, M66, and M5 by 47%, 23%, and 13%, respectively. The Disease Severity Index (DSI) indicated slower disease progression in oil palm plantlets infected with Δgit3 mutants compared to those infected with wild-type G. boninense PER71. In conclusion, this study successfully isolated and characterized the git3 GPCR from G. boninense and demonstrated that it might play a role during the early stages of infection, as the mutants were able to slow the progression of infection in oil palm plantlets.

Identification of the HbZAR1 Gene and Its Potential Role as a Minor Gene in Response to Powdery Mildew and Anthracnose of Hevea brasiliensis

Powdery mildew and anthracnose are the main diseases of rubber trees. In recent years, there have been large outbreaks in the rubber-planting areas of Asia, seriously affecting the yield and quality of rubber latex. ZAR1 is a conserved and distinctive coiled-coil nucleotide-binding leucine-rich (CNL) repeat in the plant kingdom, playing a crucial role in disease-resistance processes. To elucidate the function of the HbZAR1 gene in rubber trees (Hevea brasiliensis), three candidate HbZAR1 genes were identified using bioinformatics methods and comprehensively analyzed. The results indicate that the HbZAR1 protein is conserved in different plant species. Examination of cis-regulatory element sequences of HbZAR1genes reveals that the HbZAR1 gene promoter exhibits a remarkable enrichment of stress, light, and hormone elements. An expression analysis shows that the expression levels of the three HbZAR1 genes are highest in the bark and lowest in latex. Three HbZAR1 genes can respond to both rubber tree Erysiphe quercicola and Colletotrichum siamense infection; especially, HbZAR1.1 and HbZAR1.2 show significant upregulation in expression levels during the early stages of infection. These findings suggest that the three HbZAR1 genes may be involved in rubber tree susceptibility to E. quercicola and C. siamense through different immune mechanisms. Subcellular localization results indicate that the HbZAR1 genes are expressed in the nucleus and plasma membrane. This study also shows that the three HbZAR1 genes and activated mutant HbZAR1.1D481V do not induce stable ROS production and cell death, suggesting possible gene degradation, functional redundancy, or acting as minor genes in disease resistance. This research provides valuable insights for further studying the function of HbZAR1 genes in rubber trees and the mechanisms of immune molecules.

Clostridium spiroforme-induced diarrhea in a patient with acute myeloid leukemia: A case report

Clostridium spiroforme is a Gram-positive, obligate anaerobic bacillus. Previous studies have suggested that C. spiroforme mainly causes typhlocolitis and enterotoxemia in rabbits, with few documented cases of human infections. We present a rare case of acute diarrhea caused by C. spiroforme in a 78-year-old female patient with acute leukemia. In the early stages of infection, the patient experienced up to 10 episodes of diarrhea per day. She was subsequently treated with live Clostridium butyricum capsules to modulate the intestinal microflora, and her symptoms resolved after 7 days of treatment. This case report highlights an uncommon intestinal infection with C. spiroforme in a patient with a hematologic malignancy, contributing valuable clinical insights into this rare infection.

Early-Stage Infection-Specific Heterobasidion annosum (Fr.) Bref. Transcripts in H. annosum–Pinus sylvestris L. Pathosystem

Transcriptomes from stem-inoculated Scots pine saplings were analyzed to identify unique and enriched H. annosum transcripts in the early stages of infection. Comparing different time points since inoculation identified 131 differentially expressed H. annosum genes with p-values of ≤0.01. Our research supports the results of previous studies on the Norway spruce–Heterobasidion annosum s.l. pathosystem, indicating the role of carbohydrate and lignin degradation genes in pathogenesis at different time points post-inoculation and the role of lipid metabolism genes (including but not limited to the delta-12 fatty acid desaturase gene previously reported to be an important factor). The results of this study indicate that the malic enzyme could be a potential gene of interest in the context of H. annosum virulence. During this study, difficulties related to incomplete reference material of the host plant species and a low proportion of H. annosum transcripts in the RNA pool were encountered. In addition, H. annosum transcripts are currently not well annotated. Improvements in sequencing technologies (including sequencing depth) or bioinformatics focusing on small subpopulations of RNA would be welcome.

Immune Response of Silver Pomfret (Pampus argenteus) CC Chemokine Ligand Gene Family to Photobacterium damselae Subsp. Damselae and Nocardia seriolae Infections.

Chemokines play a crucial role in immune responses by facilitating the migration of cells expressing corresponding chemokine receptors along concentration gradients. Photobacterium damselae subsp. Damselae (PDD) and Nocardia seriolae (NS) are known to induce substantial mortality in silver pomfret populations, yet there exists a dearth of research regarding the immune response of CCLs in PDD- or NS-infected silver pomfret. In our investigation, we identified 10 PaCCLs, which include one fish-specific CCL (PaCCL44). Phylogenetic analysis revealed considerable diversity in CCL types and copy numbers among various teleost fishes. Notably, silver pomfret lacks specific CCL genes, with most PaCCLs exhibiting heightened expression levels in immune-related organs such as the spleen and kidney, and some being expressed in mucosal immune-related organs like the skin and gills. Transcriptome analysis conducted on silver pomfret infected with NS and PDD elucidated that the expression changes of PaCCLs primarily manifested in the spleen during the initial stages of NS infection, shifting to the kidney in later stages. Conversely, the expression changes of PaCCLs following PDD infection predominantly occurred in the kidney. Invitro studies using silver pomfret spleen cell lines demonstrated an early peak in PaCCLs expression during infection, followed by gradual decline with NS treatment and rapid diminishment with PDD treatment. These findings suggest that PaCCLs primarily support the innate immunity of silver pomfret, potentially exhibiting chemotactic effects in the early infection stages, such as the synergistic action of PaCCL4 and PaCCL25, and later serving as direct antibacterial agents. NS invasion is characterised by a chronic infection affecting multiple organs, whereas PDD primarily inflicts severe damage to the kidney. PaCCL19a and PaCCL19b are specific to PDD, and their expression levels may decrease in the later stages of infection due to PDD immune escape. These data offer initial insights into understanding the mechanism underlying the innate immune response of the CCL gene family in silver pomfret and provide theoretical underpinnings for fish culture practices.

Dual RNA-Seq Unveils Candidate Key Virulence Genes of Vibrio harveyi at the Early Stage of Infection in Hybrid Grouper (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus)

Vibrio harveyi is a major bacterial pathogen that causes disease in aquaculture animals worldwide. Although V. harveyi consistently harbors a range of traditional virulence genes, it remains unclear which specific genes are crucial for virulence at different infection stages. Dual RNA-seq is a cutting-edge RNA sequencing technology that is ideal for investigating the gene expression patterns of pathogens within the host, which is highly effective in identifying key virulence genes. In previous artificial infection experiments, we have identified the liver of hybrid grouper (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus) as the main target organ for pathogenic V. harveyi GDH11385 during the initial infection phase. To further explore the key virulence factors of V. harveyi at the early stage of infection, the liver of the hybrid grouper infected with strain GDH11385 was analyzed here by dual RNA-seq. The transcriptome data were compared with that of in vitro cultured bacteria. The results showed that 326 and 1140 DEGs (differentially expressed genes) were significantly up- and down-regulated, respectively, at 4 h post-infection (hpi). Further pathway enrichment analyses revealed that these up-regulated DEGs in vivo were mainly enriched in siderophore biosynthesis and transport, type VI secretion system (T6SS), flagellar assembly, glycolysis/gluconeogenesis, and ribosome. Notably, all genes involved in the metabolism and utilization of vibrioferrin (a carboxylate class of siderophore produced by Vibrio), and most of the genes within one of three T6SSs, were significantly up-regulated in vivo. This indicates that siderophore-dependent iron competition and T6SS-mediated delivery of virulence factors are vital for the successful colonization of V. harveyi at the early stage of infection. This study provides more precise clues to reveal the virulence mechanism of V. harveyi during the initial phase of infection.

BW312 Hordeum vulgare semi-dwarf mutant exhibits a shifted metabolic profile towards pathogen resistance.

Plant hormonal mutants, which do not produce or are insensitive to hormones, are often affected in their growth and development, but other metabolic rearrangements might be involved. A trade-off between growth and stress response is necessary for the plant survival. Here, we explore the metabolic profile and the pathogen resistance of a brassinosteroid-insensitive Hordeum vulgare L. semi-dwarf mutant, BW312. We investigate BW312 metabolism through a chemical enrichment analysis, confirming a shifted metabolic profile towards pathogen resistance. The effective pathogen resistance of the mutant was tested in presence of Pyrenophora teres and Fusarium graminearum. Four compound families were increased in the mutant (pyrrolidines, basic amino acids, alkaloids, monounsaturated fatty acids), while two compound families were decreased (pyrrolidinones, anthocyanins). Dipeptides were also altered (increased and decreased). BW312 displayed a better resistance to Pyrenophora teres in the earliest stage of infection with a 21.5% decrease of the lesion length 10days after infection. BW312 also exhibited a reduced lesion length (43.3%) and a reduced browning of the lesions (55.5%) when exposed to Fusarium graminearum at the seedling stage. The observed metabolomic shift strongly suggests that the BW312 semi-dwarf mutant is in a primed state, resulting in a standby state of alertness to pathogens.

Evaluation of the Epitogen Lyme Detect IgG ELISA: a novel peptide multiplexing approach.

Lyme Borreliosis (LB), or Lyme disease, is a growing health concern caused by Borrelia burgdorferi sensu lato (Bbsl) bacteria transmitted through tick bites, and untreated cases can lead to severe health complications. Existing serology tests, while valuable, have low sensitivity in early infection stages where diagnosis is vital, interpretation variability, and false positives from cross-reactivity, while direct detection methods also suffer from low sensitivity, due to the inconsistent presence of Bbsl components in clinical samples. This study validated the diagnostic performance of the novel Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay (ELISA) based on scaffold-displayed peptide antigens, using 120 specific immunodominant epitopes selected from 37 antigenic bacterial proteins corresponding to the main pathogenic Bbsl genospecies. Using 220 serum samples from Scottish patients with early, late, and disseminated LB, the assay's sensitivity was compared with that of the LIAISON Borrelia IgG CLIA, while specificity was assessed with 198 control samples, including healthy individuals and patients with diseases that are humorally similar. The Epitogen Lyme Detect IgG assay demonstrated comparable performance to the LIAISON Borrelia IgG in disseminated and late LB (Lyme neuroborreliosis, acrodermatitis chronica atrophicans, and Lyme arthritis). Notably, the Epitogen Lyme Detect IgG showed significantly higher sensitivity in patients with suspected erythema migrans, while maintaining high specificity. The Epitogen Lyme Detect IgG ELISA offers a promising advancement in LB diagnostics, demonstrating its potential for more accurate and timely diagnosis, particularly in the early stages of LB infection.IMPORTANCELyme Borreliosis (LB), caused by Borrelia burgdorferi sensu lato bacteria, poses significant health risks if undiagnosed or diagnosed late. Current diagnostic tests have limitations, especially in early-stage detection. This study validates the Epitogen Lyme Detect IgG enzyme-linked immunosorbent assay, demonstrating superior sensitivity in early LB detection while maintaining high specificity. The Epitogen Lyme Detect IgG comprises a suite of 120 immunodominant IgG epitopes/peptides from 37 bacterial antigens, covering the main LB-causing species: Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, and Borrelia mayonii. The novel design of multiplexing peptide antigens onto a scaffold to facilitate expression, correct folding, and orientation of the relevant peptides offers a promising advancement, potentially leading to more accurate and timely LB diagnoses and improving patient outcomes.

Flawonoidy – naturalne związki o potencjale przeciwwirusowym i przeciwnowotworowym

Flavonoids are a group of plant secondary metabolites that have a number of health-promoting properties and have both preventive and therapeutic effects. Research confirms that flavonoids work, among others: antiviral and anticancer. Apigenin, luteolin, isorhamnetin, kaempferol, myricetin, quercetin, hesperetin, naringenin, epicatechin and genistein have documented antiviral activity. The discovery of the anticancer activity of flavonoids (including apigenin, naringenin, hesperetin) initiated a number of studies to identify the most active compounds against various cancers and to understand the mechanism of their action. However, the relationship between flavonoid intake and cancer risk appears to be non-linear. Available literature data suggest that flavonoids may act as therapeutic agents in the early stages of virus infection and as an anticancer agent and should be included in the daily diet by increasing the consumption of primarily fruit (chokeberry, elderberry, cherry, mandarin), vegetables (parsley, celery, onion) and herbs and spices (mint, oregano, lovage, moringa, saffron). Flavonoids present in food are transported by passive diffusion (hydrophobic aglycones) and by active transport (hydrophilic glycosides). Individual classes of flavonoids differ in the amount they appear in food, the metabolites they produce and their possible impact on health. The aim of this review is to summarize the current knowledge on the potential use of selected flavonoids in the treatment of diseases of various etiologies, with an indication of their anticancer and antiviral effects. The perspectives and possibilities of using these compounds are presented, taking into account the problems resulting from their bioavailability.

Genomic transfer via membrane vesicle: a strategy of giant phage phiKZ for early infection.

Our study shed light on the processes of phage phiKZ early infection stage, expanding our understanding of possible strategies for the development of phage infection. We show that phiKZ virion content during injection is packed inside special membrane structures called early phage infection (EPI) membrane vesicles originating from the bacterial inner cell membrane. We demonstrated the EPI vesicle fulfilled the role of the safety transport unit for the phage genome to the phage nucleus, where the phage DNA would be replicated and protected from bacterial immune systems.

Cloning and Identification of Common Carp (Cyprinus carpio) PI3KC3 and Its Expression in Response to CyHV-3 Infection.

Phosphoinositide 3-kinases (PI3Ks) are a class of key regulatory factors in eukaryotes that can inhibit viral replication by influencing autophagy. Currently, cyprinid herpesvirus 3 (CyHV-3) poses a serious threat to common carp culture. However, PI3K has not yet been identified in common carp. In this study, full-length PI3KC3 from common carp (CcPI3KC3), consisting of an open reading frame (ORF) of 2664 bp encoding a polypeptide of 887 amino acids, with a predicted molecular mass of 101.19 kDa and a theoretical isoelectric point (pI) of 5.97, was cloned. The amino acid and nucleotide sequences of CcPI3KC3 displayed high similarity to yellow catfish's (Tachysurus fulvidraco) PI3KC3. The tissue expression profile revealed that the mRNA levels of CcPI3KC3 in the liver, spleen, and head kidney were significantly greater than those in the brain, heart, intestines, gills, eyes, testes, and ovaries of common carp. We compared the expression patterns of CcPI3KC3 between "Longke-11" mirror carp (CyHV-3-resistant carp) and German mirror carp (non-resistant to CyHV-3) at different times (0, 48, 96, 144 h, 192, 240, 288 h post-infection (hpi)) after CyHV-3 infection. The results revealed that CcPI3KC3 mRNA expression significantly increased in the early infection stage. In the CyHV-3-resistant mirror carp variety, the relative expression of CcPI3KC3 was significantly greater at 48, 96, and 144 hpi compared with the nonbreeding strain groups after infection (p < 0.001). These results indicate that the full-length CcPI3KC3 sequence was successfully cloned from common carp for the first time, and it might play an important role in the immune system of common carp against CyHV-3 infection. This study provides a theoretical basis for the molecular mechanism of CyHV-3 resistance.

CqProfilin enhances WSSV infection by promoting viral intracellular transport through binding to both viral nucleocapsid and actin cytoskeleton

White spot syndrome virus (WSSV) is a large nuclear-replicating DNA virus of crustaceans such as shrimp and crayfish; however, the molecular mechanisms facilitating its transport from the invasion site to the cell nucleus have not yet been well elucidated. In this study, a CqProfilin (CqPFN) with a conserved PROF domain was identified from the red claw crayfish Cherax quadricarinatus. CqPFN was ubiquitously expressed in all examined tissues and hemocyte, with the highest levels in the hemocyte, followed by hematopoietic tissue (Hpt) from which the hemocyte were derived in crayfish. The transcript of WSSV genes such as IE1 and VP28 was obviously decreased both in vivo in hemocyte and Hpt, as well as in vitro in cultured Hpt cells, after CqPFN gene silencing; in contrast, the expression of viral genes was significantly increased by the introduction of a recombinant CqPFN protein in Hpt cells in vitro. Moreover, CqPFN was clearly colocalized with the main viral nucleocapsid protein VP664 and F-actin cytoskeleton, respectively, during the early stage of WSSV infection in Hpt cells. In addition, CqPFN was confirmed to interact with a truncated VP6642,405-2,535 and another viral nucleocapsid protein VP15 of WSSV and Cqβ-Actin from Hpt by co-immunoprecipitation assays. Further studies found that VP664 also colocalized with F-actin in the Hpt cell cytoplasm after WSSV infection, suggesting that the actin cytoskeleton was involved in the intracellular transport of incoming viral nucleocapsid. Taken together, CqPFN might combine with the actin cytoskeleton to promote WSSV infection through binding with viral nucleocapsid proteins VP664 and VP15, promoting intracellular transport of viral incoming nucleocapsid for further releasing genome into the nucleus for transcription. Collectively, these results provided an understanding of the WSSV pathogenesis, which will contribute to the development of an antiviral strategy against WSSV disease.

PK205R targets the proximal element of IFN-I signaling pathway to assist African swine fever virus to escape host innate immunity at the early stage of infection.

African swine fever virus (ASFV) is a nuclear cytoplasmic large DNA virus (NCLDV) that causes devastating hemorrhagic diseases in domestic pigs and wild boars, seriously threatening the development of the global pig industry. IFN-I plays an important role in the body's antiviral response. Similar to other DNA viruses, ASFV has evolved a variety of immune escape strategies to antagonize IFN-I signaling and maintain its proliferation. In this study, we showed that the ASFV early protein pK205R strongly inhibited interferon-stimulated genes (ISGs) as well as the promoter activity of IFN-stimulated regulatory elements (ISREs). Mechanistically, pK205R interacted with the intracellular domains of IFNAR1 and IFNAR2, thereby inhibiting the interaction of IFNAR1/2 with JAK1 and TYK2 and hindering the phosphorylation and nuclear translocation of STATs. Subsequently, we generated a recombinant strain of the ASFV-pK205R point mutation, ASFV-pK205R7PM. Notably, we detected higher levels of ISGs in porcine alveolar macrophages (PAMs) than in the parental strain during the early stages of ASFV-pK205R7PM infection. Moreover, ASFV-pK205R7PM attenuated the inhibitory effect on IFN-I signaling. In conclusion, we identified a new ASFV immunosuppressive protein that increases our understanding of ASFV immune escape mechanisms.

Characterisation of the antibody-mediated selective pressure driving intra-host evolution of SARS-CoV-2 in prolonged infection.

Neutralising antibodies against the SARS-CoV-2 spike (S) protein are major determinants of protective immunity, though insufficient antibody responses may cause the emergence of escape mutants. We studied the humoral immune response causing intra-host evolution in a B-cell depleted, haemato-oncologic patient experiencing clinically severe, prolonged SARS-CoV-2 infection with a virus of lineage B.1.177.81. Following bamlanivimab treatment at an early stage of infection, the patient developed a bamlanivimab-resistant mutation, S:S494P. After five weeks of apparent genetic stability, the emergence of additional substitutions and deletions within the N-terminal domain (NTD) and the receptor binding domain (RBD) of S was observed. Notably, the composition and frequency of escape mutations changed in a short period with an unprecedented dynamic. The triple mutant S:Delta141-4 E484K S494P became dominant until virus elimination. Routine serology revealed no evidence of an antibody response in the patient. A detailed analysis of the variant-specific immune response by pseudotyped virus neutralisation test, surrogate virus neutralisation test, and immunoglobulin-capture enzyme immunoassay showed that the onset of an IgM-dominated antibody response coincided with the appearance of escape mutations. The formation of neutralising antibodies against S:Delta141-4 E484K S494P correlated with virus elimination. One year later, the patient experienced clinically mild re-infection with Omicron BA.1.18, which was treated with sotrovimab and resulted in an increase in Omicron-reactive antibodies. In conclusion, the onset of an IgM-dominated endogenous immune response in an immunocompromised patient coincided with the appearance of additional mutations in the NTD and RBD of S in a bamlanivimab-resistant virus. Although virus elimination was ultimately achieved, this humoral immune response escaped detection by routine diagnosis and created a situation temporarily favouring the rapid emergence of various antibody escape mutants with known epidemiological relevance.

Serum lipidome reveals lipid metabolic dysregulation in severe fever with thrombocytopenia syndrome

BackgroundSevere fever with thrombocytopenia syndrome (SFTS) is a rapidly progressing infectious disease with a high fatality rate caused by a novel bunyavirus (SFTSV). The role of lipids in viral infections is well-documented; however, the specific alterations in lipid metabolism during SFTSV infection remain elusive. This study aims to elucidate the lipid metabolic dysregulations in the early stages of SFTS patients.MethodsThis study prospectively collected peripheral blood sera from 11 critical SFTS patients, 37 mild SFTS patients, and 23 healthy controls during the early stages of infection for lipidomics analysis. A systematic bioinformatics analysis was conducted from three aspects integrating lipid differential expressions, lipid differential correlations, and lipid-clinical indices correlations to reveal the serum lipid metabolic dysregulation in SFTSV-infected individuals.ResultsOur findings reveal significant lipid metabolic dysregulation in SFTS patients. Specifically, compared to healthy controls, SFTS patients exhibited three distinct modes of lipid differential expression: increased levels of lipids including phosphatidylserine (PS), hexosylceramide (HexCer), and triglycerides (TG); decreased levels of lipids including lysophosphatidylcholine (LPC), acylcarnitine (AcCa), and cholesterol esters (ChE); and lipids showing “dual changes” including phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Finally, based on lipid metabolic pathways and literature analysis, we systematically elucidated the potential mechanisms underlying lipid metabolic dysregulation in the early stage of SFTSV infection.ConclusionsOur study presents the first global serum lipidome profile and reveals the lipid metabolic dysregulation patterns in the early stage of SFTSV infection. These findings provide a new basis for the diagnosis, treatment, and further investigation of the disease.

Multiple mechanisms enable broad-spectrum activity of the Pelargonium sidoides root extract EPs 7630 against acute respiratory tract infections.

There is clinical evidence showing that the Pelargonium sidoides root extract EPs 7630 is a safe and effective treatment for a range of acute infectious respiratory illnesses. Moreover, EPs 7630 has been shown to reduce the use of antibiotics, which is important in the context of rising antibiotic resistance levels. A wide range of mechanisms appears to contribute to the beneficial effects of EPs 7630, e.g. antibacterial, antiviral, immunomodulatory, and epithelial barrier effects. This broad spectrum of pharmacological activities seems to enable the clinical activity of EPs 7630 against multiple respiratory infections. In particular, the combination of antiviral and immunomodulatory effects may enable EPs 7630 to tackle acute viral respiratory infections both in early stages of the disease process, which are driven by virus replication, as well as in later stages, which are caused by an overshooting immune response. Hence, EPs 7630 is a prime example of a plant extract with evidence-based clinical efficacy, including a solid understanding of the underlying mechanisms of action. The example of EPs 7630 demonstrates that plant extracts have a potential role as evidence-based clinical treatments and that they deserve pre-clinical and clinical testing and investigation in the same way as any other drug class.

Singapore grouper iridovirus VP12 evades the host antiviral immune response by targeting the cGAS-STING signalling pathway.

The emergence of Singapore grouper iridovirus (SGIV) has caused huge losses to grouper farming. SGIV is a DNA virus and belongs to the genus Ranavirus. Groupers infected with SGIV showed haemorrhaging and swelling of the spleen, with a mortality rate of more than 90% within a week. Therefore, it is of great significance to study the escape mechanism of SGIV from host innate immunity for the prevention and treatment of viral diseases in grouper. In this study, the viral proteins that interact with EccGAS were identified by mass spectrometry, and the SGIV VP12 protein that inhibits cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-mediated antiviral innate immunity was screened by the dual-luciferase reporter gene assay. VP12 belongs to the late gene of the virus. The immunofluorescence analysis demonstrated that VP12 was aggregated and distributed in the cytoplasm during the early stage of virus infection and translocated into the nucleus at the late stage of virus infection. VP12 inhibited the activation of IFN3, ISRE and NF-κB promoter activities mediated by cGAS-STING, EcTBK1 and EcIRF3. Quantitative real-time PCR analysis showed that VP12 inhibited the expression of interferon-related genes, including those mediated by cGAS-STING. VP12 enhanced the inhibition of IFN3, ISRE and NF-κB promoter activity by EccGAS, EccGAS-mab-21 and EccGAS-delete-mab21. The interaction between VP12 and EccGAS was found to be domain independent. The immunoprecipitation results demonstrated that VP12 interacted and co-localized with EccGAS, EcTBK1 and EcIRF3. VP12 degraded the protein levels of EcTBK1 and EcIRF3 and degraded EcIRF3 through the protease pathway. These results suggest that SGIV VP12 protein escapes the cGAS-STING signalling pathway and degrades EcIRF3 protein expression through the protease pathway.