Strong association of regulatory single nucleotide polymorphisms (SNPs) of the IFITM3 gene with influenza H1N1 2009 pandemic virus infection

Host Innate Antiviral Response to Influenza A Virus Infection: From Viral Sensing to Antagonism and Escape

Influenza virus possesses an RNA genome of single-stranded, negative-sensed, and segmented configuration. Influenza virus causes an acute respiratory disease, commonly known as the "flu" in humans. In some individuals, flu can lead to pneumonia and acute respiratory distress syndrome. Influenza A virus (IAV) is the most significant because it causes recurring seasonal epidemics, occasional pandemics, and zoonotic outbreaks in human populations, globally. The host innate immune response to IAV infection plays a critical role in sensing, preventing, and clearing the infection as well as in flu disease pathology. Host cells sense IAV infection through multiple receptors and mechanisms, which culminate in the induction of a concerted innate antiviral response and the creation of an antiviral state, which inhibits and clears the infection from host cells. However, IAV antagonizes and escapes many steps of the innate antiviral response by different mechanisms. Herein, we review those host and viral mechanisms. This review covers most aspects of the host innate immune response, i.e., (1) the sensing of incoming virus particles, (2) the activation of downstream innate antiviral signaling pathways, (3) the expression of interferon-stimulated genes, (4) and viral antagonism and escape.

IFITM3 inhibits severe fever with thrombocytopenia syndrome virus entry and interacts with viral Gc protein

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne hemorrhagic fever disease with high fatality rate of 10%-20%. Vaccines or specific therapeutic measures remain lacking. Human interferon inducible transmembrane protein 3 (hIFITM3) is a broad-spectrum antiviral factor targeting viral entry. However, the antiviral activity of hIFITM3 against SFTS virus (SFTSV) and the functional mechanism of IFITM3 remains unclear. Here we demonstrate that endogenous IFITM3 provides protection against SFTSV infection and participates in the anti-SFTSV effect of type Ⅰ and Ⅲ interferons (IFNs). IFITM3 overexpression exhibits anti-SFTSV function by blocking Gn/Gc-mediated viral entry and fusion. Further studies showed that IFITM3 binds SFTSV Gc directly and its intramembrane domain (IMD) is responsible for this interaction and restriction of SFTSV entry. Mutation of two neighboring cysteines on IMD weakens IFITM3-Gc interaction and attenuates the antiviral activity of IFITM3, suggesting that IFITM3-Gc interaction may partly mediate the inhibition of SFTSV entry. Overall, our data demonstrate for the first time that hIFITM3 plays a critical role in the IFNs-mediated anti-SFTSV response, and uncover a novel mechanism of IFITM3 restriction of SFTSV infection, highlighting the potential of clinical intervention on SFTS disease.

Influenza Virus Host Restriction Factors: The ISGs and Non-ISGs

Influenza virus has been one of the most prevalent and researched viruses globally. Consequently, there is ample information available about influenza virus lifecycle and pathogenesis. However, there is plenty yet to be known about the determinants of influenza virus pathogenesis and disease severity. Influenza virus exploits host factors to promote each step of its lifecycle. In turn, the host deploys antiviral or restriction factors that inhibit or restrict the influenza virus lifecycle at each of those steps. Two broad categories of host restriction factors can exist in virus-infected cells: (1) encoded by the interferon-stimulated genes (ISGs) and (2) encoded by the constitutively expressed genes that are not stimulated by interferons (non-ISGs). There are hundreds of ISGs known, and many, e.g., Mx, IFITMs, and TRIMs, have been characterized to restrict influenza virus infection at different stages of its lifecycle by (1) blocking viral entry or progeny release, (2) sequestering or degrading viral components and interfering with viral synthesis and assembly, or (3) bolstering host innate defenses. Also, many non-ISGs, e.g., cyclophilins, ncRNAs, and HDACs, have been identified and characterized to restrict influenza virus infection at different lifecycle stages by similar mechanisms. This review provides an overview of those ISGs and non-ISGs and how the influenza virus escapes the restriction imposed by them and aims to improve our understanding of the host restriction mechanisms of the influenza virus.

PRNP gene polymorphism frequencies for comparing possible vulnerability to BSE in Chinese bovine population

Among the numerous transmissible spongiform encephalopathies (TSEs), bovine spongiform encephalopathy (BSE) is the most well-known TSEs. It is a potential Creutzfeldt-Jakob (CJD) disease mutation that can be transferred through cattle to humans. In several animals, the prion protein gene (PRNP) is recognized to take active part in TSE vulnerability or tolerance. Previous studies have found indels polymorphism in PRNP gene promoter and intron1 region linked to BSE vulnerability. It's linked with 23 bp indels polymorphism in putative promoter and 12 bp indel in intron 1 of the PRNP gene. The aim of this study was to compare the allele, genotype and haplotype frequencies of PRNP indel polymorphisms in Zhongdian Yak (Bos grunniens) (YK), Zhongdian Yellow cattle (Bos taurus) (YC) and Zhongdian Yakow (Bos primigenius taurus × Bos grunniens) (PK) with worldwide reported healthy or affected BSE cattle, in order to assess their potential resistance to BSE. A comparison of Chinese bovine populations with healthy and BSE-affected German and Swiss cattle from globally was conducted, and result indicating significant difference (p < .001) between healthy and affected cattle. Additionally, as compared to prior studies with Chinese bovine population, the significant results were found. In this study, the allelic frequency D23 finding high deletion in all analyzed Chinese bovine species, and haplotype D12-D23 exhibited a less significant inclination toward susceptibility to BSE.

The significance of IFITM3 polymorphism in COVID-19 asymptomatic and ICU admission Kurdish patients

BACKGROUND

The Coronavirus Disease 2019 (COVID-19) is a global pandemic that exhibits a wide range of clinical symptoms, from asymptomatic to critically ill infections that require admission to an intensive care unit (ICU). Interferon-induced transmembrane protein 3 (IFITM3) prevents the viral envelope fusion with the cell membrane, hence playing a crucial role in the immune response. The association between single nucleotide polymorphisms (SNPs) in the IFITM3 gene and the severity of COVID-19 is controversial among various ethnic groups.

METHODS

Seven IFITM3 SNPs were genotyped based on DNA sequencing to investigate the association between these variants and asymptomatic and ICU-admitted COVID-19 patients of the Kurdish nation.

RESULTS

The present study found a significant association between rs12252 and the clinical outcome of COVID-19 (chi2 = 14.83, P = 0.00). The dominant, AA genotype model was significantly associated with a 5.212-fold increased risk of asymptomatic disease (P = 0.000, OR = 5.212). Patients with the GTA haplotypes rs12252, rs34481144, rs7478728 were shown to have a 3.9-fold increased risk of being admitted to the ICU (P = 0.003, OR = 3.9).

CONCLUSION

This study demonstrated that the rs12252 AA genotype is probably associated with asymptomatic COVID-19. In addition, the patients having haplotypes of minor alleles rs12252, rs34481144, and rs7478728 may be associated to COVID-19 ICU admission.

A comprehensive review of ACE2, ACE1, TMPRSS2 and IFITM3 gene polymorphisms and their effect on the severity of COVID-19

Recent events have raised concerns about the outbreak of a pandemic by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An infection caused by a virus can provoke an inflammatory reaction, which can result in severe lung damage, failure of several organs, and death. The unique genetic makeup of each individual may be a component in the development of each of these responses. In this context, genetic variants of the genes linked to the invasion of the virus into the host's body can be analyzed. Various elements have a function in viral entry. ACE2 is used by SARS-CoV-2 as a receptor to enter the cell. TMPRSS2 is then responsible for cutting the virus into its components. In addition, lung damage occurs when there is an imbalance between ACE1 and ACE2. Another component that plays a significant role in virus penetration is called IFITM3, which is created as a reaction to interferon. This protein prevents viruses in the Coronaviridae family from entering cells. This study aimed to analyze DNA polymorphisms in the ACE2, ACE1, TMPRSS2, and IFITM3 genes. Findings showed certain polymorphisms appear to be associated with the severity of the disease, including respiratory, coronary, and neurological disorders. The results also indicated that certain polymorphisms were protective against this virus. Varying populations have a different frequency of high-risk polymorphisms, so different treatment and preventative techniques must be implemented. Additional population studies should be conducted in this region to reduce the incidence of COVID-19-related morbidity and mortality.

Interferon-Induced Transmembrane Protein 3 rs34481144 C/T Genotype and Clinical Parameters Related to Progression of COVID-19

Recent research has associated the interferon-induced transmembrane protein 3 gene (IFITM3) with the outcomes of coronavirus disease 2019 (COVID-19), although the findings are contradictory. This study aimed to determine the relationship between IFITM3 gene rs34481144 polymorphism and clinical parameters with COVID-19 mortality. The tetra-primer amplification refractory mutation system-polymerase chain reaction assay was used to analyze IFITM3 rs34481144 polymorphism in 1,149 deceased and 1,342 recovered patients. The clinical parameters were extracted from the patients' medical records. In this study, the frequency of IFITM3 rs34481144 CT genotypes (OR 1.47, 95% CI 1.23-1.76, P < 0.0001) in both sexes was significantly higher in deceased patients than in recovered patients. Moreover, IFITM3 rs34481144 TT genotypes (OR 3.38, 95% CI 1.05-10.87, P < 0.0001) in women were significantly associated with COVID-19 mortality. The multivariable logistic regression model results indicated that mean age (P < 0.001), alkaline phosphatase (P = 0.005), alanine aminotransferase (P < 0.001), low-density lipoprotein (P < 0.001), high-density lipoprotein (P < 0.001), fasting blood glucose (P = 0.010), creatinine (P < 0.001), uric acid (P < 0.001), C-reactive protein (P = 0.004), 25-hydroxyvitamin D (P < 0.001), erythrocyte sedimentation rate (P < 0.001), and real-time PCR Ct values (P < 0.001) were linked with increased COVID-19 death rates. In conclusion, IFITM3 rs34481144 gene polymorphism was linked to the mortality of COVID-19, with the rs34481144-T allele being especially important for mortality. Further studies are needed to confirm the results of this study.

Cyclosporines Antagonize the Antiviral Activity of IFITMProteins by Redistributing Them toward the Golgi Apparatus

Interferon-induced transmembrane proteins (IFITMs) block the fusion of diverse enveloped viruses, likely through increasing the cell membrane's rigidity. Previous studies have reported that the antiviral activity of the IFITM family member, IFITM3, is antagonized by cell pretreatment with rapamycin derivatives and cyclosporines A and H (CsA and CsH) that promote the degradation of IFITM3. Here, we show that CsA and CsH potently enhance virus fusion with IFITM1- and IFITM3-expressing cells by inducing their rapid relocalization from the plasma membrane and endosomes, respectively, towards the Golgi. This relocalization is not associated with a significant degradation of IFITMs. Although prolonged exposure to CsA induces IFITM3 degradation in cells expressing low endogenous levels of this protein, its levels remain largely unchanged in interferon-treated cells or cells ectopically expressing IFITM3. Importantly, the CsA-mediated redistribution of IFITMs to the Golgi occurs on a much shorter time scale than degradation and thus likely represents the primary mechanism of enhancement of virus entry. We further show that rapamycin also induces IFITM relocalization toward the Golgi, albeit less efficiently than cyclosporines. Our findings highlight the importance of regulation of IFITM trafficking for its antiviral activity and reveal a novel mechanism of the cyclosporine-mediated modulation of cell susceptibility to enveloped virus infection.

Targeting CXCL16 and STAT1 augments immune checkpoint blockade therapy in triple-negative breast cancer

Chemotherapy prior to immune checkpoint blockade (ICB) treatment appears to improve ICB efficacy but resistance to ICB remains a clinical challenge and is attributed to highly plastic myeloid cells associating with the tumor immune microenvironment (TIME). Here we show by CITE-seq single-cell transcriptomic and trajectory analyses that neoadjuvant low-dose metronomic chemotherapy (MCT) leads to a characteristic co-evolution of divergent myeloid cell subsets in female triple-negative breast cancer (TNBC). Specifically, we identify that the proportion of CXCL16 + myeloid cells increase and a high STAT1 regulon activity distinguishes Programmed Death Ligand 1 (PD-L1) expressing immature myeloid cells. Chemical inhibition of STAT1 signaling in MCT-primed breast cancer sensitizes TNBC to ICB treatment, which underscores the STAT1's role in modulating TIME. In summary, we leverage single-cell analyses to dissect the cellular dynamics in the tumor microenvironment (TME) following neoadjuvant chemotherapy and provide a pre-clinical rationale for modulating STAT1 in combination with anti-PD-1 for TNBC patients.

Increased risk of COVID-19 mortality rate in IFITM3 rs6598045 G allele carriers infected by SARS-CoV-2 delta variant

BACKGROUND

The interferon-induced transmembrane-protein 3 (IFITM3) is a vital component of the immune system's defense against viral infection. Variants in the IFITM3 gene have been linked to changes in expression and the risk of severe Coronavirus disease 2019 (COVID-19). This study aimed to investigate whether IFITM3 rs6598045, quantitative polymerase chain reaction (qPCR) cycle threshold (Ct) values, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are associated with an increased mortality rate of COVID-19.

METHODS

The genotyping of IFITM3 rs6598045 polymorphism was analyzed using the amplification refractory mutation system-polymerase chain reaction in 1342 recovered and 1149 deceased patients positive for SARS-CoV-2.

RESULTS

In this study, IFITM3 rs6598045 G allele as minor allele frequency was significantly more common in the deceased patients than in the recovered ones. Furthermore, the highest mortality rates were observed in Delta variant and lowest qPCR Ct values. COVID-19 mortality was associated with IFITM3 rs6598045 GG and AG in Delta variant and IFITM3 rs6598045 AG in Alpha variant. A statistically significant difference was observed in the qPCR Ct values between individuals with GG and AG genotypes and those with an AA genotype.

CONCLUSION

A possible correlation was observed between the mortality rate of COVID-19, the G allele of IFITM3 rs6598045, and SARS-CoV-2 variants. However, large-scale research is still required to validate our results.

No association of prion protein gene (PRNP) polymorphisms with susceptibility to the pandemic 2009 swine flu

Background

The pandemic 2009 swine flu is a highly infectious respiratory disorder caused by H1N1 influenza A viruses. A recent study reported that knockout of the prion protein gene (PRNP) induced susceptibility and lethality in influenza A virus-infected mice.

Objective

Thus, we examined the association between genetic variations of the PRNP gene and susceptibility to pandemic 2009 swine flu.

Results

We did not find an association between PRNP polymorphisms and susceptibility to pandemic 2009 swine flu.

Conclusions

To the best of our knowledge, this was the first evaluation of the association between PRNP polymorphisms and vulnerability to pandemic 2009 swine flu.

Comparing the Cytokine Storms of COVID-19 and Pandemic Influenza

Emerging respiratory viruses are major health threats due to their potential to cause massive outbreaks. Over the past 2 years, the coronavirus disease 2019 (COVID-19) pandemic has caused millions of cases of severe infection and deaths worldwide. Although natural and vaccine-induced protective immune mechanisms against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been increasingly identified, the factors that determine morbimortality are less clear. Comparing the immune signatures of COVID-19 and other severe respiratory infections such as the pandemic influenza might help dissipate current controversies about the origin of their severe manifestations. As such, identifying homologies in the immunopathology of both diseases could provide targets for immunotherapy directed to block shared pathogenic mechanisms. Meanwhile, finding unique characteristics that differentiate each infection could shed light on specific immune alterations exploitable for diagnostic and individualized therapeutics for each case. In this study, we summarize immunopathological aspects of COVID-19 and pandemic influenza from the perspective of cytokine storms as the driving force underlying morbidity. Thereby, we analyze similarities and differences in the cytokine profiles of both infections, aiming to bring forward those molecules more attractive for translational medicine and drug development.

Development of a chicken interferon-induced transmembrane protein 3 (IFITM3)-specific monoclonal antibody using phage display

Interferon-induced transmembrane protein 3 (IFITM3) has potent antiviral activity against several viruses. Recent studies have reported that the chicken IFITM3 gene also plays a pivotal role in blocking viral replication, but these studies are considerably limited due to being conducted at the RNA level only. Thus, the development of a chicken IFITM3 protein-specific antibody is needed to validate the function of IFITM3 at the protein level. Epitope prediction was performed with the immune epitope database analysis resource (IEDB-AR) program. The epitope was validated by four in silico programs, Jped4, Clustal Omega, TMpred and SOSUI. Chicken IFITM3 protein-specific monoclonal antibodies were screened by enzyme-linked immunosorbent assay through affinity between recombinant IFITM3 protein and phage-displayed candidate antibodies. Validation of the reactivity of the chicken IFITM3 protein-specific antibody to chicken tissues was carried out using western blotting. We developed a chicken IFITM3 protein-specific monoclonal antibody using phage display. The reactivity of the antibody with peripheral chicken tissues was confirmed using western blotting. To the best of our knowledge, this was the first development of a chicken IFITM3 protein-specific monoclonal antibody using phage display.

Differential Leukocyte Expression of IFITM1 and IFITM3 in Patients with Severe Pandemic Influenza A(H1N1) and COVID-19

Interferon-induced transmembrane (IFITM) proteins mediate protection against enveloped viruses by blocking membrane fusion at endosomes. IFITM1 and IFITM3 are crucial for protection against influenza, and various single nucleotide polymorphisms altering their function have been linked to disease susceptibility. However, bulk IFITM1 and IFITM3 mRNA expression dynamics and their correlation with clinical outcomes have not been extensively addressed in patients with respiratory infections. In this study, we evaluated the expression of IFITM1 and IFITM3 in peripheral leukocytes from healthy controls and individuals with severe pandemic influenza A(H1N1) or coronavirus disease 2019 (COVID-19). Comparisons between participants grouped according to their clinical characteristics, underlying disease, and outcomes showed that the downregulation of IFITM1 was a distinctive characteristic of severe pandemic influenza A(H1N1) that correlated with outcomes, including mortality. Conversely, increased IFITM3 expression was a common feature of severe pandemic influenza A(H1N1) and COVID-19. Using a high-dose murine model of infection, we confirmed not only the downregulation of IFITM1 but also of IFITM3 in the lungs of mice with severe influenza, as opposed to humans. Analyses in the comparative cohort also indicate the possible participation of IFITM3 in COVID-19. Our results add to the evidence supporting a protective function of IFITM proteins against viral respiratory infections in humans.

No Association between Single Nucleotide Polymorphisms (SNPs) of the Interferon-Induced Transmembrane Protein 3 (IFITM3) Gene and the Susceptibility of Alzheimer’s Disease (AD)

Background and Objectives: Alzheimer’s disease (AD) is the most common progressive neurodegenerative disorder, characterized by the accumulation of amyloid-beta (Aβ) in the brain. A recent study reported that the interferon-induced transmembrane protein 3 (IFITM3) protein plays a pivotal role in Aβ processing by the γ-secretase complex. Since several single nucleotide polymorphisms (SNPs) of the IFITM3 gene are related to the function and expression levels of the IFITM3 gene, the relationship between genetic polymorphisms in the IFITM3 gene and susceptibility to AD needs to be investigated. Materials and Methods: We investigated the genotype and allele frequencies of IFITM3 polymorphisms in 177 AD patients and 233 matched healthy controls by amplicon sequencing. In addition, we compared the genotype, allele and haplotype frequencies between AD patients and matched controls and performed an association analysis. Results: There were no significant differences in the genotype, allele or haplotype frequency distributions of the IFITM3 polymorphisms between AD patients and matched controls. Conclusions: To the best of our knowledge, this is the first case-control association study of the IFITM3 gene in AD.

Regulatory Single Nucleotide Polymorphism of the Bovine IFITM3 Gene Induces Differential Transcriptional Capacities of Hanwoo and Holstein Cattle

Interferon-induced transmembrane protein 3 (IFITM3), a crucial effector of the host's innate immune system, prohibits an extensive range of viruses. Previous studies have reported that single nucleotide polymorphisms (SNPs) of the IFITM3 gene are associated with the expression level and length of the IFITM3 protein and can impact susceptibility to infectious viruses and the severity of infection with these viruses. However, there have been no studies on polymorphisms of the bovine IFITM3 gene. In the present study, we finely mapped the bovine IFITM3 gene and annotated the identified polymorphisms. We investigated polymorphisms of the bovine IFITM3 gene in 108 Hanwoo and 113 Holstein cattle using direct sequencing and analyzed genotype, allele, and haplotype frequencies and linkage disequilibrium (LD) between the IFITM3 genes of the two cattle breeds. In addition, we analyzed transcription factor-binding sites and transcriptional capacity using PROMO and luciferase assays, respectively. Furthermore, we analyzed the effect of a nonsynonymous SNP of the IFITM3 gene using PolyPhen-2, PANTHER, and PROVEAN. We identified 23 polymorphisms in the bovine IFITM3 gene and found significantly different genotype, allele, and haplotype frequency distributions and LD scores between polymorphisms of the bovine IFITM3 gene in Hanwoo and Holstein cattle. In addition, the ability to bind the transcription factor Nkx2-1 and transcriptional capacities were significantly different depending on the c.-193T > C allele. Furthermore, nonsynonymous SNP (F121L) was predicted to be benign. To the best of our knowledge, this is the first genetic study of bovine IFITM3 polymorphisms.

Polymorphisms of the prion-related protein gene are strongly associated with cervids' susceptibility to chronic wasting disease

BACKGROUND

Chronic wasting disease (CWD) is a cervid prion disease that is caused by abnormal prion protein (PrP^Sc ). Recent studies have reported that prion family genes showed a strong association with the susceptibility of several types of prion diseases. To date, an association study of the prion-related protein gene (PRNT) has not been performed in any type of cervid prion disease.

METHODS

In the present study, we investigated PRNT polymorphisms in large deer, including 235 elk, 257 red deer and 150 sika deer. We compared genotype, allele and haplotype frequencies of PRNT polymorphisms between CWD-negative animals and CWD-positive animals to find an association of PRNT polymorphisms with the susceptibility of CWD.

RESULTS

We found a total of five novel single nucleotide polymorphisms (SNPs) in the cervid PRNT gene. Interestingly, we observed significantly different distributions of genotypes and allele frequencies of three PRNT SNPs, including c.108C>T, c.159+30C>T and c.159+32A>C, between CWD-negative and CWD-positive red deer. In addition, significant differences of two haplotype frequencies in red deer were found between the CWD-negative and CWD-positive groups. However, the association identified in the red deer was not found in elk and sika deer.

CONCLUSION

To the best of our knowledge, this report is the first to describe the strong association of PRNT SNPs with the susceptibility of CWD.

Host polymorphisms and COVID-19 infection

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus, severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). There is growing evidence that host genetics play an important role in COVID-19 severity. Based on current knowledge about the human protein machinery for SARS-CoV-2 entry, the host innate immune response, and virus-host interactions, the potential effects of human genetic polymorphisms, which may contribute to clinical differences in SARS-CoV-2 pathogenesis, may help to determine the individual risk for COVID-19 infection and outcome.

Phylogenetic and topological analyses of the bovine interferon-induced transmembrane protein (IFITM3)

Interferon-induced transmembrane protein 3 (IFITM3) plays a pivotal role in antiviral capacity in several species. However, to date, investigations of the IFITM3 protein in cattle have been rare. According to recent studies, interspecific differences in the IFITM3 protein result in several unique features of the IFITM3 protein relative to primates and birds. Thus, in the present study, we investigated the bovine IFITM3 protein based on nucleotide and amino acid sequences to find its distinct features. We found that the bovine IFITM3 gene showed a significantly different length and homology relative to other species, including primates, rodents and birds. Phylogenetic analyses indicated that the bovine IFITM3 gene and IFITM3 protein showed closer evolutionary distance with primates than with rodents. However, cattle showed an independent clade among primates, rodents and birds. Multiple sequence alignment of the IFITM3 protein indicated that the bovine IFITM3 protein contains 36 bovine-specific amino acids. Notably, the bovine IFITM3 protein was predicted to prefer inside-to-outside topology of intramembrane domain 1 (IMD1) and inside-to-outside topology of transmembrane domain 2 by TMpred and three membrane embedding domains according to the SOSUI system.

The influence of IFITM3 polymorphisms on susceptibility to SARS-CoV-2 infection and severity of COVID-19

Background and aims

The interferon-induced transmembrane protein 3 (IFITM3) plays an important role in the adaptive and innate immune response by inhibiting viral membrane hemifusion between the host and viral cell cytoplasm. Single nucleotide polymorphisms (SNPs) in the gene IFITM3 have been associated with susceptibility and severity of influenza or other viral infections. We aimed to analyze the role of SNPs in the gene IFITM3 in SARS-CoV-2 infection.

Methods

We performed genotyping of the SNPs rs12252 and rs34481144 in the gene IFITM3 in 239 SARS-CoV-2-positive and 253 SARS-CoV-2-negative patients. We analyzed the association of the SNPs with susceptibility to SARS-CoV-2 infection and severity of COVID-19.

Results

SARS-CoV-2-positive and SARS-CoV-2-negative patients did not differ regarding demographics. Neither IFITM3 rs12252 nor rs34481144 polymorphisms were related to SARS-CoV-2 infection risk or severity of COVID-19. Interestingly, we observed the putative deleterious rs12252 CC genotype only in SARS-CoV-2-positive patients (N = 2). Also, we found a non-significant higher frequency of rs34481144 A-allele carriers in the patients with 'serious' COVID-19.

Conclusions

In summary, we could not confirm the recently reported influence of polymorphisms in the gene IFITM3 on SARS-CoV-2 infection risk or severity of COVID-19 in a German cohort. Additional studies are needed to clarify the influence of the rs12252 CC genotype on SARS-CoV-2 infection risk and the rs34481144 A-allele on course of COVID-19.

Genome-Wide Association Study Identifies Eight Novel Loci for Susceptibility of Scrub Typhus and Highlights Immune-Related Signaling Pathways in Its Pathogenesis

Scrub typhus is a fatal zoonotic disease caused by Orientia tsutsugamushi. This disease is accompanied by systemic vasculitis, lymphadenopathy, headache, myalgia, and eschar. In recent studies, a novel strain that is resistant to current medical treatment was identified in Thailand. Thus, the development of new specific drugs for scrub typhus is needed. However, the exact molecular mechanism governing the progression of scrub typhus has not been fully elucidated. To understand disease-related genetic factors and mechanisms associated with the progression of scrub typhus, we performed a genome-wide association study (GWAS) in scrub typhus-infected patients and found a scrub typhus-related signaling pathway by molecular interaction search tool (MIST) and PANTHER. We identified eight potent scrub typhus-related single nucleotide polymorphisms (SNPs) located on the PRMT6, PLGLB2, DTWD2, BATF, JDP2, ONECUT1, WDR72, KLK, MAP3K7, and TGFBR2 genes using a GWAS. We also identified 224 genes by analyzing protein-protein interactions among candidate genes of scrub typhus and identified 15 signaling pathways associated with over 10 genes by classifying these genes according to signaling pathways. The signaling pathway with the largest number of associated genes was the gonadotropin-releasing hormone receptor pathway, followed by the TGF-beta signaling pathway and the apoptosis signaling pathway. To the best of our knowledge, this report describes the first GWAS in scrub typhus.

The first association study of single-nucleotide polymorphisms (SNPs) of the IFITM1 gene with influenza H1N1 2009 pandemic virus infection

Background

The interferon-induced transmembrane (IFITM) protein family consists of interferon-stimulated genes (ISGs) that show potent antiviral capacity against a broad range of viruses. Many studies have been performed to investigate an association between IFITM3 polymorphisms and pandemic influenza A 2009 H1N1 virus infection. However, an association study of IFITM1 polymorphisms with susceptibility to this infection has not been reported thus far.

Objective

To identify an association between the susceptibility to pandemic influenza A 2009 H1N1 virus infection and IFITM1 polymorphisms, we compared genotype, allele and haplotype frequencies of the IFITM1 gene between healthy controls and pandemic influenza A 2009 H1N1-infected patients. In addition, we investigated linkage disequilibrium (LD) by Haploview 4.2 and the binding ability of transcription factors according to IFITM1 polymorphism alleles by PROMO. Furthermore, we measured the LD value between the IFITM1 gene and the IFITM3 gene.

Results

We found 3 novel single-nucleotide polymorphisms (SNPs) and did not find an association between IFITM1 SNPs and susceptibility to pandemic influenza A 2009 H1N1 virus infection. We found strong LD among IFITM1 SNPs but did not find a difference in the transcription factor-binding ability according to regulatory IFITM1 SNP alleles. In addition, we found strong LD between IFITM1 SNPs and IFITM3 SNPs.

Conclusion

To the best of our knowledge, this report is the first association study of the susceptibility to pandemic influenza A 2009 H1N1 virus infection and IFITM1 polymorphisms.

Strong Association of the rs4986790 Single Nucleotide Polymorphism (SNP) of the Toll-Like Receptor 4 (TLR4) Gene with Human Immunodeficiency Virus (HIV) Infection: A Meta-Analysis

Human immunodeficiency virus (HIV) causes acquired immune deficiency syndrome (AIDS) and enters the host cell via CD4 and either CC-chemokine receptor 5 (CCR) or CXC-chemokine receptor 4 (CXCR4). HIV is directly recognized by toll-like receptor 4 (TLR4) and affects downstream immune-related signal pathways. In addition, stimulated TLR4 inhibits HIV-1 invasion, and the rs4986790 single nucleotide polymorphism (SNP) (D299G) of the TLR4 gene contributes to the risk of HIV-1 infection in an Indian population. To evaluate whether the rs4986790 SNP of the TLR4 gene is related to vulnerability to HIV-1 infection, we collected genetic information from HIV-1 patients in previous studies and performed an association analysis with a matched control population obtained from the 1000 Genomes Project. In addition, to strengthen the results of association analysis, we performed a meta-analysis. We identified a strong association between the rs4986791 SNP and susceptibility to HIV infection in HIV-infected patients in previous studies and a matched control population obtained from the 1000 Genomes Project. In addition, we found that the G allele of the rs4986791 SNP in the TLR4 gene is strongly related to susceptibility to HIV infection in three Caucasian populations (odd ratio = 2.29, 95% confidence interval: 1.72–3.07, p = 1.438 × 10⁻⁷) and all four populations (odd ratio = 2.22, 95% confidence interval: 1.74–2.84, p = 2 × 10⁻¹⁰) in a meta-analysis. To the best our knowledge, this was the first meta-analysis on the association between the rs4986791 SNP of the TLR4 gene and susceptibility to HIV infection.

Strong Correlation between the Case Fatality Rate of COVID-19 and the rs6598045 Single Nucleotide Polymorphism (SNP) of the Interferon-Induced Transmembrane Protein 3 (IFITM3) Gene at the Population-Level

Coronavirus disease 2019 (COVID-19) is a fatal pandemic disease that is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of 13 December, 2020, over 70,000,000 cases and 1,500,000 deaths have been reported over a period of several months; however, the mechanism underlying the pathogenesis of COVID-19 has not been elucidated. To identify the novel risk genetic biomarker for COVID-19, we evaluated the correlation between the case fatality rate of COVID-19 and the genetic polymorphisms of several potential COVID-19-related genes, including interferon-induced transmembrane protein 3 (IFITM3), the angiotensin I converting enzyme 2 (ACE2) gene, transmembrane protease, serine 2 (TMPRSS2), interleukin 6 (IL6), leucine zipper transcription factor-like protein 1 (LZTFL1), and the ABO genes, in various ethnic groups. We obtained the number of COVID-19 cases and deaths from the World Health Organization (WHO) COVID-19 dashboard and calculated the case fatality rate of each ethnic group. In addition, we obtained the allele distribution of the polymorphisms of the IFITM3, ACE2, TMPRSS2, IL6, LZTFL1, and ABO genes from the 1000 Genomes Project and performed Log-linear regression analysis using SAS version 9.4. We found different COVID-19 case fatality rates in each ethnic group. Notably, we identified a strong correlation between the case fatality rate of COVID-19 and the allele frequency of the rs6598045 single nucleotide polymorphism (SNP) of the IFITM3 gene. To the best of our knowledge, this report is the first to describe a strong correlation between the COVID-19 case fatality rate and the rs6598045 SNP of the IFITM3 gene at the population-level.

Ethnic variation in risk genotypes based on single nucleotide polymorphisms (SNPs) of the interferon-inducible transmembrane 3 (IFITM3) gene, a susceptibility factor for pandemic 2009 H1N1 influenza A virus

The interferon-inducible transmembrane 3 (IFITM3) protein is an effector of the host innate immune system that shows defensive activity against a wide range of viruses, including the influenza A virus. Previous studies have reported that three transcription-related regulatory single nucleotide polymorphisms (SNPs), rs12252, rs34481144, and rs6598045, showed potent associations with the severity of pandemic influenza A 2009 infection and susceptibility to this virus, respectively. However, the distribution of the risk genotypes of these three SNPs according to ethnic background has remained elusive. In this study, we compared the genotype and allele frequencies of the IFITM3 polymorphisms among several ethnic groups including American, African, European, South Asian, and East Asian using chi-square test. In addition, we analyzed the worldwide distribution of risk genotypes for pandemic influenza A 2009 virus infection. We found that the genotype and allele distributions of the rs12252, rs34481144, and rs6598045 SNPs were significantly different among several ethnic groups. In addition, the risk genotypes of the IFITM3 polymorphisms were also significantly different worldwide. To the best of our knowledge, this was the first simultaneous estimation of the risk genotypes of the IFITM3 gene with respect to pandemic influenza A 2009 virus infection.

Genetic association between the rs12252 SNP of the interferon-induced transmembrane protein gene and influenza A virus infection in the Korean population

Background

Interferon-induced transmembrane protein 3 (IFITM3) is a potent host antiviral effector protein that blocks the invasion of various viruses, including the influenza A virus (IAV). The C allele of the rs12252 single nucleotide polymorphism (SNP) shows vulnerability to the pandemic 2009 H1N1 IAV in European and Asian populations.

Objective

Here, we estimated the disease susceptibility of the rs12252 SNP with the pandemic 2009 H1N1 IAV infection in the Korean population.

Results

We carried out direct sequencing of the IFITM3 gene and compared the genotype and allele frequencies of the rs12252 SNP of the IFITM3 gene in healthy Koreans and pandemic 2009 H1N1 IAV-infected patients. Notably, we observed that healthy individuals had a similar genotype distribution of the rs12252 SNP (P = 0.140) as patients. The dominant model and recessive model did not find a statistically significant difference in genotype distribution between healthy individuals and patients. In addition, the allele distribution of the rs12252 SNP of in healthy individuals and patients also showed a similar genetic distribution (P = 0.757). However, the genetic distribution of rs12252 SNP in merged patient group (Koreans and Chinese populations) showed significant association with susceptibility of pandemic 2009 IAV (P = 0.0393).

Conclusion

To the best of our knowledge, this was the first evaluation of the susceptibility of the pandemic 2009 H1N1 IAV in the Korean population.

Comprehensive analysis of two potential novel SARS-CoV-2 entries, TMPRSS2 and IFITM3, in healthy individuals and cancer patients

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, with acute respiratory failure as the most significant symptom, has led to a global pandemic. Angiotensin-converting enzyme 2 (ACE2) is considered as the most important receptor of SARS-CoV-2 and wildly expressed in human tissues. Whereas, the extremely low expression of ACE2 in lung could hardly interpret the severe symptom of pneumonia in COVID-19 patients. Here we profiled two SARS-CoV-2 infection related genes, the transmembrane serine protease 2 (TMPRSS2) and the interferon-inducible transmembrane protein 3 (IFITM3), in human tissues and organs. Consistent with the expression and distribution of ACE2, TMPRSS2 was also highly expressed in digestive, urinary and reproductive systems, but low expressed in lung. Notably, the anti-virus protein IFITM3 also expressed much lower in lung than other tissues, which might be related to the severe lung symptoms of COVID-19. In addition, the low expression of IFITM3 in immune cells suggested that SARS-CoV-2 might attack lymphocytes and induce the cytokine release syndrome (CRS). Furthermore, cancer patients were considered as more susceptible to SARS-CoV-2 infection. Our data supposed that fourteen types of tumors might have different susceptibility to the virus according to ACE2, TMPRSS2 and IFITM3 expression patterns. Interestingly the prognosis of six types of cancers including breast carcinoma (BRCA), lung adenocarcinoma (LUAD), uterine corpus endometrial carcinoma (UCEC), renal clear cell carcinoma (KIRC), prostate adenocarcinoma (PRAD), and hepatocellular carcinoma (LIHC) were closely related to these gene expressions. Our study explored the expression and distribution profiles of two potential novel molecules that might participate in SARS-CoV-2 infection and involved in immunity, which may provide a functional basis for preventing infection of SARS-CoV-2.

Polymorphisms of shadow of prion protein gene (SPRN) in Korean native cattle (Hanwoo) and Holstein cattle

Bovine spongiform encephalopathy (BSE) is a fatal infectious neurodegenerative disease caused by the accumulation of pathogenic prion protein (PrP^Sc) in the central nervous system (CNS), particularly in the brain. In a recent study, the shadow of prion protein (Sho), encoded by the shadow of prion protein (SPRN) gene, accelerates the progression of prion diseases, and a 12-bp insertion/deletion polymorphism in the coding region of the SPRN gene is associated with susceptibility to atypical BSE-affected Polish cattle. To date, the genetic study of the SPRN gene in Korean cattle has not been performed. In this study, we investigated the genotype and allele frequencies of SPRN polymorphisms in 235 Hanwoo and 212 Holstein cattle and analyzed the linkage disequilibrium (LD) and haplotypes of SPRN polymorphisms. In addition, we compared the distribution of the 12-bp insertion/deletion polymorphism between atypical BSE-diagnosed Polish cattle and Korean cattle to evaluate the susceptibility of atypical BSE. Furthermore, we estimated a deleterious effect of polymorphisms on the Sho protein using PROVEAN. We found a total of seven polymorphisms, including one novel single nucleotide polymorphism (SNP), c.231G>A. We also found significantly different distributions of genotype, allele and haplotype frequencies of seven polymorphisms between Hanwoo and Korean Holstein cattle. In addition, all polymorphisms showed strong LDs among the seven polymorphisms. Interestingly, Hanwoo cattle showed more potential susceptible distribution in the genotype and allele frequencies of the 12-bp insertion/deletion polymorphisms of the SPRN gene than Holstein cattle. Finally, using PROVEAN, we found one novel deleterious nonsynonymous SNP to Sho protein, c.110G>C (G37A). To the best of our knowledge, this is the first study of the SPRN gene in Korean cattle.

Infectivity and Progression of COVID-19 Based on Selected Host Candidate Gene Variants

Introduction: Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has spread around the globe. Susceptibility has been associated with age, biological sex, and other prior existing health conditions. However, host genes are involved in viral infectivity and pathogenicity, and polymorphisms in these could be responsible for the interethnic/interindividual variability observed in infection and progression of COVID-19. Materials and Methods: Clinical exome data of 103 individuals was analyzed to identify sequence variants in five selected candidate genes: ACE2, TMPRSS2, CD209, IFITM3, and MUC5B to assess their prevalence and role to understand the COVID-19 infectivity and progression in our population. Results: A total of 497 polymorphisms were identified in the five selected genes in the exomes analyzed. Thirty-eight polymorphisms identified in our cohort have been reported earlier in literature and have functional significance or association with health conditions. These variants were classified into three groups: protective, susceptible, and responsible for comorbidities. Discussion and Conclusion: The two polymorphisms described in literature as risk inducing are rs35705950 in MUC5B gene and TMPRSS2 haplotype (rs463727, rs34624090, rs55964536, rs734056, rs4290734, rs34783969, rs11702475, rs35899679, and rs35041537) were absent in our cohort explaining the slower infectivity of the disease in this part of India. The 38 functional variants identified can be used as a predisposition panel for the COVID-19 infectivity and progression and stratify individuals as "high or low risk," which would help in planning appropriate surveillance and management protocols. A larger study from different regions of India is warranted to validate these results.

Investigation of Human IFITM3 Polymorphisms rs34481144A and rs12252C and Risk for Influenza A(H1N1)pdm09 Severity in a Brazilian Cohort

Influenza is a major public health problem that causes acute respiratory infection in humans. Identification of host factors influencing in disease outcome is critical for recognition of individuals with increased risk. Investigations on the role of rs34481144A and rs12252C IFITM3 polymorphisms in influenza A(H1N1)pdm09 severity is not yet conclusively determined. This study aimed to evaluate such polymorphisms frequencies and IFITM3 levels in an infected Brazilian cohort of 314 influenza A(H1N1)pdm09 cases and its putative association with clinical, epidemiological and virological data. Individuals were clinically classified into mild, severe and fatal cases. IFITM3 polymorphisms were detected by specific Taqman probes in real time PCR reactions. IFITM3 levels were determined by quantitative real time PCR. Thus, the different clinical groups presented similar distribution of rs34481144 and rs12252 genotypes and allelic frequencies. There was no significant association between the polymorphisms with severity of disease by using distinct genetic models. Additionally, geographic distribution of mutants showed that rs34481144A allele was more predominant in Brazilian Southern region. In contrast, rs12252C allele presented similar frequencies in all regions. Individuals with the distinct rs34481144 and rs12252 genotypes showed similar levels of IFITM3 and viral load in their respiratory specimens. Furthermore, IFITM3 levels were comparable in the distinct clinical groups and were not correlated with influenza viral load in analyzed samples. Thereby, rs34481144A and rs12252C polymorphisms were not associated with severity or mortality of influenza A(H1N1)pdm09 infection nor with IFITM3 transcript levels and influenza viral load in upper respiratory tract samples in a Brazilian cohort.

Identification of Prion Disease-Related Somatic Mutations in the Prion Protein Gene (PRNP) in Cancer Patients

Prion diseases are caused by misfolded prion protein (PrP^Sc) and are accompanied by spongiform vacuolation of brain lesions. Approximately three centuries have passed since prion diseases were first discovered around the world; however, the exact role of certain factors affecting the causative agent of prion diseases is still debatable. In recent studies, somatic mutations were assumed to be cause of several diseases. Thus, we postulated that genetically unstable cancer tissue may cause somatic mutations in the prion protein gene (PRNP), which could trigger the onset of prion diseases. To identify somatic mutations in the PRNP gene in cancer tissues, we analyzed somatic mutations in the PRNP gene in cancer patients using the Cancer Genome Atlas (TCGA) database. In addition, to evaluate whether the somatic mutations in the PRNP gene in cancer patients had a damaging effect, we performed in silico analysis using PolyPhen-2, PANTHER, PROVEAN, and AMYCO. We identified a total of 48 somatic mutations in the PRNP gene, including 8 somatic mutations that are known pathogenic mutations of prion diseases. We identified significantly different distributions among the types of cancer, the mutation counts, and the ages of diagnosis between the total cancer patient population and cancer patients carrying somatic mutations in the PRNP gene. Strikingly, although invasive breast carcinoma and glioblastoma accounted for a high percentage of the total cancer patient population (9.9% and 5.4%, respectively), somatic mutations in the PRNP gene have not been identified in these two cancer types. We suggested the possibility that somatic mutations of the PRNP gene in glioblastoma can be masked by a diagnosis of prion disease. In addition, we found four aggregation-prone somatic mutations, these being L125F, E146Q, R151C, and K204N. To the best of our knowledge, this is the first specific analysis of the somatic mutations in the PRNP gene in cancer patients.

Identification of the novel polymorphisms and potential genetic features of the prion protein gene (PRNP) in horses, a prion disease-resistant animal

Prion diseases, a protein misfolded disorder (PMD) caused by misfolded prion protein (PrP^Sc), present in a wide variety of hosts, ranging from ungulates to humans. To date, prion infections have not been reported in horses, which are well-known as prion disease-resistant animals. Several studies have attempted to identify distinctive features in the prion protein of horses compared to prion disease-susceptible animals, without the study on polymorphisms of the horse prion protein gene (PRNP). Since single nucleotide polymorphisms (SNPs) of PRNP in prion disease-susceptible animals are major susceptibility factors, the investigation of SNPs in the horse PRNP gene is important; however, only one study investigated a single horse breed, Thoroughbred. Thus, we investigated genetic polymorphisms and potential characteristics of the PRNP gene in 2 additional horse breeds. To this end, we performed amplicon sequencing of the horse PRNP gene and investigated SNPs in Jeju and Halla horses. We compared genotype, allele and haplotype frequencies among three horse breeds, namely, Thoroughbred, Jeju and Halla horses. In addition, we evaluated the potential influence of the identified nonsynonymous SNPs on the prion protein using PolyPhen-2, PROVEAN, and PANTHER. Furthermore, we measured the aggregation propensity of prion proteins using AMYCO and analyzed linkage disequilibrium (LD) between PRNP and prion-like protein gene (PRND) SNPs. A total of 4 SNPs were found, including two nonsynonymous SNPs (c.301 T > A, c.525 C > A) and three novel SNPs (c.-3A > G, c.301 T > A and c.570 G > A). There were significant differences in genotype, allele and haplotype frequencies among the three horse breeds. The nonsynonymous SNP, c.301 T > A (W101R), was predicted to be benign, deleterious, and possibly damaging by PolyPhen-2, PROVEAN and PANTHER, respectively. In addition, the amyloid propensity of horse prion protein according to 4 haplotypes of nonsynonymous SNPs was predicted to be benign by AMYCO. Finally, we identified weak LD between PRNP and PRND SNPs.

Absence of Strong Genetic Linkage Disequilibrium between Single Nucleotide Polymorphisms (SNPs) in the Prion Protein Gene (PRNP) and the Prion-Like Protein Gene (PRND) in the Horse, a Prion-Resistant Species

Prion disease is a fatal neurodegenerative disorder caused by a deleterious prion protein (PrP^Sc). However, prion disease has not been reported in horses during outbreaks of transmissible spongiform encephalopathies (TSEs) in various animals in the UK. In previous studies, single nucleotide polymorphisms (SNPs) in the prion protein gene (PRNP) have been significantly associated with susceptibility to prion disease, and strong linkage disequilibrium (LD) between PRNP and prion-like protein gene (PRND) SNPs has been identified in prion disease-susceptible species. On the other hand, weak LD values have been reported in dogs, a prion disease-resistant species. In this study, we investigated SNPs in the PRND gene and measured the LD values between the PRNP and PRND SNPs and the impact of a nonsynonymous SNP found in the horse PRND gene. To identify SNPs in the PRND gene, we performed direct sequencing of the PRND gene. In addition, to assess whether the weak LD value between the PRNP and PRND SNPs is a characteristic of prion disease-resistant animals, we measured the LD value between the PRNP and PRND SNPs using D’ and r² values. Furthermore, we evaluated the impact of a nonsynonymous SNP in the Doppel protein with PolyPhen-2, PROVEAN, and PANTHER. We observed two novel SNPs, c.331G > A (A111T) and c.411G > C. The genotype and allele frequencies of the c.331G > A (A111T) and c.411G > C SNPs were significantly different between Jeju, Halla, and Thoroughbred horses. In addition, we found a total of three haplotypes: GG, AG, and GC. The GG haplotype was the most frequently observed in Jeju and Halla horses. Furthermore, the impact of A111T on the Doppel protein was predicted to be benign by PolyPhen-2, PROVEAN, and PANTHER. Interestingly, a weak LD value between the PRNP and PRND SNPs was found in the horse, a prion disease-resistant animal. To the best of our knowledge, these results suggest that a weak LD value could be one feature of prion disease-resistant animals.

The First Report of Genetic and Structural Diversities in the SPRN Gene in the Horse, an Animal Resistant to Prion Disease

Prion diseases are fatal neurodegenerative diseases and are characterized by the accumulation of abnormal prion protein (PrP^Sc) in the brain. During the outbreak of the bovine spongiform encephalopathy (BSE) epidemic in the United Kingdom, prion diseases in several species were reported; however, horse prion disease has not been reported thus far. In previous studies, the shadow of prion protein (Sho) has contributed to an acceleration of conversion from normal prion protein (PrP^C) to PrP^Sc, and the shadow of prion protein gene (SPRN) polymorphisms have been significantly associated with the susceptibility of prion diseases. We investigated the genotype, allele and haplotype frequencies of the SPRN gene using direct sequencing. In addition, we analyzed linkage disequilibrium (LD) and haplotypes among polymorphisms. We also investigated LD between PRNP and SPRN single nucleotide polymorphisms (SNPs). We compared the amino acid sequences of Sho protein between the horse and several prion disease-susceptible species using ClustalW2. To perform Sho protein modeling, we utilized SWISS-MODEL and Swiss-PdbViewer programs. We found a total of four polymorphisms in the equine SPRN gene; however, we did not observe an in/del polymorphism, which is correlated with the susceptibility of prion disease in prion disease-susceptible animals. The SPRN SNPs showed weak LD value with PRNP SNP. In addition, we found 12 horse-specific amino acids of Sho protein that can induce significantly distributional differences in the secondary structure and hydrogen bonds between the horse and several prion disease-susceptible species. To the best of our knowledge, this is the first report regarding the genetic and structural characteristics of the equine SPRN gene.

Macrophages reprogrammed by lung cancer microparticles promote tumor development via release of IL-1β

Despite their mutual antagonism, inflammation and immunosuppression coexist in tumor microenvironments due to tumor and immune cell interactions, but the underlying mechanism remains unclear. Previously, we showed that tumor cell-derived microparticles induce an M2 phenotype characterized by immunosuppression in tumor-infiltrating macrophages. Here, we further showed that lung cancer microparticles (L-MPs) induce macrophages to release a key proinflammatory cytokine, IL-1β, thus promoting lung cancer development. The underlying mechanism involves the activation of TLR3 and the NLRP3 inflammasome by L-MPs. More importantly, tyrosine kinase inhibitor treatment-induced L-MPs also induce human macrophages to release IL-1β, leading to a tumor-promoting effect in a humanized mouse model. These findings demonstrated that in addition to their anti-inflammatory effect, L-MPs induce a proinflammatory phenotype in tumor-infiltrating macrophages, promoting the development of inflammatory and immunosuppressive tumor microenvironments.