RESUMO
BACKGROUND: Growing evidence has suggested that Type I Interferon (I-IFN) plays a potential role in the pathogenesis of Down Syndrome (DS). This work investigates the underlying function of MX1, an effector gene of I-IFN, in DS-associated transcriptional regulation and phenotypic modulation. METHODS: We performed assay for transposase-accessible chromatin with high-throughout sequencing (ATAC-seq) to explore the difference of chromatin accessibility between DS derived amniocytes (DSACs) and controls. We then combined the annotated differentially expressed genes (DEGs) and enriched transcriptional factors (TFs) targeting the promoter region from ATAC-seq results with the DEGs in RNA-seq, to identify key genes and pathways involved in alterations of biological processes and pathways in DS. RESULTS: Binding motif analysis showed a significant increase in chromatin accessibility of genes related to neural cell function, among others, in DSACs, which is primarily regulated by members of the activator protein-1 (AP-1) transcriptional factor family. Further studies indicated that MX Dynamin Like GTPase 1 (MX1), defined as one of the key effector genes of I-IFN, is a critical upstream regulator. Its overexpression induced expression of AP-1 TFs and mediated inflammatory response, thus leading to decreased cellular viability of DS cells. Moreover, treatment with specific AP-1 inhibitor T-5224 improved DS-associated phenotypes in DSACs. CONCLUSIONS: This study demonstrates that MX1-mediated AP-1 activation is partially responsible for cellular dysfunction of DS. T-5224 effectively ameliorated DS-associated phenotypes in DSACs, suggesting it as a potential treatment option for DS patients.
Assuntos
Síndrome de Down , Fator de Transcrição AP-1 , Humanos , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Sequenciamento de Cromatina por Imunoprecipitação , RNA-Seq , Síndrome de Down/tratamento farmacológico , Síndrome de Down/genética , Cromatina , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismoRESUMO
One of the major causes of early pregnancy loss is heat stress. In ruminants, interferon tau (IFNT) is the embryo signal to the mother. Once the interferon signaling pathway is activated, it drives gene expression for interferon-stimulated genes (ISGs) and alters neutrophils responses. The aim of the present study was to evaluate interferon (IFN) pathway, ISGs and gene expression in polymorphonuclear leukocytes (PMN) and oxidative stress in dairy cows under heat stress. Pregnant cows had their estrous cycle synchronized and randomly assigned to a comfort or heat stress group. Blood samples were collected at artificial insemination (AI) and on Days 10, 14 and 18 following AI. Pregnant cows were pregnancy checked by ultrasound on Day 30 and confirmed on Day 60 post-AI. Results are presented as mean ± SEM. The corpus luteum (CL) diameter was not different between groups of pregnant cows; concentration of progesterone of pregnant cows on Day 18 following AI was greater in comfort group compared to heat stressed group. Comfort pregnant cows had higher expression of all analyzed genes from interferon pathway, except for IFNAR1, on both Days 14 and 18. Conversely, heat stressed cows did not show altered expression of IFNT pathway genes and ISGs between Days 10, 14, and 18 after AI. The oxidative stress, determined as malondialdehyde (MDA) levels, was greater in heat stress group on Days 10, 14 and 18, independent of pregnancy status. Heat stress negatively influences expression of ISGs, IFN pathway gene expression in neutrophils, and oxidative stress. Our data suggest that lower conception rates in cows under heat stress are multifactorial, with the association of interferon pathway activation and the unbalanced oxidative stress being main contributing factors.
Assuntos
Resposta ao Choque Térmico/genética , Interferons/metabolismo , Neutrófilos/metabolismo , Estresse Oxidativo , Animais , Bovinos , Corpo Lúteo/diagnóstico por imagem , Corpo Lúteo/fisiologia , Citocinas/genética , Citocinas/metabolismo , Feminino , Inseminação Artificial/veterinária , Malondialdeído/sangue , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Neutrófilos/citologia , Gravidez , Progesterona/sangue , Temperatura , UltrassonografiaRESUMO
BACKGROUND: Genetic background may be an important host determinant of respiratory syncytial virus (RSV) disease severity, but full characterization of susceptibility genes remains unclear. This study aimed to assess the presence of specific single-nucleotide polymorphisms (SNPs) in selected genes codifying for different components of the antiviral innate immune response, to determine their role for developing RSV life-threatening disease (LTD). METHODS: Prospective cohort study including previously healthy full-term infants hospitalized with a first RSV infection during 2017-2018. RSV detection, quantification and subgroup determination, and genotyping for SNPs in Toll-like receptor 4 (TLR4 rs4986790, rs4986791), Toll-like receptor 8 (TLR8 rs3761624), macrophage receptor with collagenous structure(MARCO rs1318645) and myxovirus resistance 1(MX1 rs469390) were performed by real-time polymerase chain reaction in nasopharyngeal aspirates obtained on admission. Patients with LTD were those admitted to the intensive care unit requiring ventilatory support. RESULTS: Seventy-five patients were studied, 15 (20%) developed LTD. Infants with concurrent SNPs in MX1 and TLR8, MARCO and TLR8 or MARCO, MX1 and TLR8 had an increased risk of developing LTD. Multivariable logistic regression analysis confirmed this significant association (odds ratio [OR] = 3.75, P = 0.046; OR = 3.92, P = 0.040; OR = 5.56, P = 0.010, respectively). No differences were seen in viral load of patients with LTD compared with those with better outcome (P = 0.737). In addition, no differences in viral load were seen in patients with the described high-risk SNPs compared with those without these polymorphisms. CONCLUSIONS: Life-threatening RSV infection in previously healthy infants was significantly associated with the presence of combined SNPs in MARCO, MX1 and TLR8.
Assuntos
Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Infecções por Vírus Respiratório Sincicial/genética , Criança Hospitalizada , Feminino , Humanos , Imunidade Inata , Lactente , Masculino , Proteínas de Resistência a Myxovirus/genética , Estudos Prospectivos , Receptores Imunológicos/genética , Infecções por Vírus Respiratório Sincicial/imunologia , Receptor 4 Toll-Like/genética , Receptor 8 Toll-Like/genética , Carga ViralRESUMO
This study characterised the expression of interferon (IFN)-τ-stimulated genes (ISGs) and Type I IFN receptors in circulating polymorphonuclear cells (PMNs) of beef heifers and compared it with expression in peripheral blood mononuclear cells (PBMCs) up to Day 20 of gestation. Nelore heifers (n=26) were subjected to fixed-time AI (FTAI) on Day 0. PMNs and PBMCs were isolated on Days 0, 10, 14, 16, 18 and 20 after FTAI. The abundance of target transcripts (ubiquitin-like protein (ISG15), 2'-5'-oligoadenylate synthetase 1 (OAS1), myxovirus resistance 1 (MX1), myxovirus resistance 2 (MX2), IFN receptor I (IFNAR1) and IFN receptor 2 (IFNAR2)) was determined using real-time quantitative polymerase chain reaction and compared between pregnant (n=8) and non-pregnant (n=9) females. In both PBMCs and PMNs, ISG15 and OAS1 expression was greater in pregnant than non-pregnant heifers on Days 18 and 20. There were no significant differences in the expression of ISGs between PBMCs and PMNs. A time effect on expression was found for IFNAR1 in PBMCs and IFNAR2 in PMNs, with decreased expression of both genes on Days 18 and 20. When the expression of these genes was compared between cell types only in pregnant heifers, IFNAR2 expression in PMNs had an earlier decrease when compared to its expression in PBMCs, starting from Day 18. In conclusion, PMNs do not respond earlier to the conceptus stimulus, and ISG15 and OAS1 expression in both PMNs and PBMCs can be used as a suitable marker for pregnancy diagnosis on Days 18 and 20. In addition, gestational status did not affect IFNAR1 and IFNAR2 expression, but IFNAR2 showed a distinct response between PMNs and PBMCs of pregnant heifers.
Assuntos
2',5'-Oligoadenilato Sintetase/metabolismo , Leucócitos Mononucleares/metabolismo , Proteínas de Resistência a Myxovirus/metabolismo , Neutrófilos/metabolismo , Receptor de Interferon alfa e beta/metabolismo , Ubiquitinas/metabolismo , 2',5'-Oligoadenilato Sintetase/genética , Animais , Bovinos , Feminino , Proteínas de Resistência a Myxovirus/genética , Gravidez , Progesterona/sangue , Receptor de Interferon alfa e beta/genética , Ubiquitinas/genéticaRESUMO
The inflammatory tumor microenvironment is a fertile niche accelerating prostate cancer (PCa). We have reported that heme-oxygenase (HO-1) had a strong anti-tumoral effect in PCa. We previously undertook an in-depth proteomics study to build the HO-1 interactome in PCa. In this work, we used a bioinformatics approach to address the biological significance of HO-1 interactors. Open-access PCa datasets were mined to address the clinical significance of the HO-1 interactome in human samples. HO-1 interactors were clustered into groups according to their expression profile in PCa patients. We focused on the myxovirus resistance gene (MX1) as: (1) it was significantly upregulated under HO-1 induction; (2) it was the most consistently downregulated gene in PCa vs. normal prostate; (3) its loss was associated with decreased relapse-free survival in PCa; and (4) there was a significant positive correlation between MX1 and HMOX1 in PCa patients. Further, MX1 was upregulated in response to endoplasmic reticulum stress (ERS), and this stress triggered apoptosis and autophagy in PCa cells. Strikingly, MX1 silencing reversed ERS. Altogether, we showcase MX1 as a novel HO-1 interactor and downstream target, associated with ERS in PCa and having a high impact in the clinical setting.
Assuntos
Biologia Computacional/métodos , Heme Oxigenase-1/metabolismo , Proteínas de Resistência a Myxovirus/metabolismo , Neoplasias da Próstata/metabolismo , Estudos de Casos e Controles , Proliferação de Células , Mineração de Dados , Bases de Dados Genéticas , Estresse do Retículo Endoplasmático , Regulação Neoplásica da Expressão Gênica , Heme Oxigenase-1/genética , Humanos , Masculino , Proteínas de Resistência a Myxovirus/genética , Células PC-3 , Neoplasias da Próstata/genética , Análise de Sobrevida , Microambiente TumoralRESUMO
The bovine viral diarrhea virus (BVDV-1) is a pathogen responsible for high economic losses in the cattle industry worldwide. This virus has the capacity to modulate the immune system of several higher vertebrates, but there is little information available on the cell infection mechanism. To further investigate the effects of BVDV-1 on the activation of the immune response, the Madin-Darby bovine kidney cell line was infected with the cytopathic CH001 field isolate of BVDV-1, and the proinflammatory and antiviral cytokine expression profiles were analyzed. The results showed that BVDV-1 was able to induce the production of BCL3, IL-1ß, IL-8, IL-15, IL-18, Mx-1, IRF-1, and IRF-7 in a way similar to polyinosinic-polycytidylic acid. Interestingly, all BVDV-1 activities were blocked by pharmacological inhibitors of the NF-κB signaling pathway. These results, together with in silico analyses showing the presence of several regulatory consensus target motifs, suggest that BVDV-1 regulates gene expression in bovines through the activation of several key transcription factors. Collectively, these data identified BVDV-1 as a viral regulator of immune marker expression, even from early infection. Additionally, this is the first report to find BVDV-1 modulating the activation of cytokine production and transcriptions factors mainly through the NF-κB pathway in vertebrates.
Assuntos
Vírus da Diarreia Viral Bovina/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Interleucinas/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Nitrilas/farmacologia , Sulfonas/farmacologia , Animais , Proteína 3 do Linfoma de Células B , Biomarcadores/metabolismo , Bovinos , Linhagem Celular , Vírus da Diarreia Viral Bovina/crescimento & desenvolvimento , Vírus da Diarreia Viral Bovina/imunologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Células Epiteliais/virologia , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/imunologia , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/imunologia , Interleucinas/genética , Interleucinas/imunologia , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Poli I-C/farmacologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/imunologia , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/imunologiaRESUMO
Lichen planus (LP) is a common inflammatory skin disease of unknown etiology. Reports of a common transactivation of quiescent human endogenous retroviruses (HERVs) support the connection of viruses to the disease. HERVs are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancer and autoimmune diseases. We explored the transcriptional activity of HERV sequences as well as the antiviral restriction factor and interferon-inducible genes in the skin from LP patients and healthy control (HC) donors. The study included 13 skin biopsies from patients with LP and 12 controls. Real-time PCR assay identified significant decrease in the HERV-K gag and env mRNA expression levels in LP subjects, when compared to control group. The expressions of HERV-K18 and HERV-W env were also inhibited in the skin of LP patients. We observed a strong correlation between HERV-K gag with other HERV sequences, regardless the down-modulation of transcripts levels in LP group. In contrast, a significant up-regulation of the cytidine deaminase APOBEC 3G (apolipoprotein B mRNA-editing), and the GTPase MxA (Myxovirus resistance A) mRNA expression level was identified in the LP skin specimens. Other transcript expressions, such as the master regulator of type I interferon-dependent immune responses, STING (stimulator of interferon genes) and IRF-7 (interferon regulatory factor 7), IFN-ß and the inflammassome NALP3, had increased levels in LP, when compared to HC group. Our study suggests that interferon-inducible factors, in addition to their role in innate immunity against exogenous pathogens, contribute to the immune control of HERVs. Evaluation of the balance between HERV and interferon-inducible factor expression could possibly contribute to surveillance of inflammatory/malignant status of skin diseases.
Assuntos
Retrovirus Endógenos/metabolismo , Produtos do Gene env/metabolismo , Produtos do Gene gag/metabolismo , Interferon beta/metabolismo , Líquen Plano/imunologia , Proteínas de Membrana/metabolismo , Proteínas da Gravidez/metabolismo , Pele/metabolismo , Superantígenos/metabolismo , Desaminase APOBEC-3G , Adulto , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Retrovirus Endógenos/genética , Feminino , Regulação Viral da Expressão Gênica , Produtos do Gene env/genética , Produtos do Gene gag/genética , Humanos , Vigilância Imunológica , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/metabolismo , Interferon beta/genética , Líquen Plano/genética , Líquen Plano/virologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas da Gravidez/genética , Pele/virologia , Superantígenos/genética , Ativação Transcricional , Regulação para Cima , Adulto JovemRESUMO
Certain host single nucleotide polymorphisms (SNPs) affect the likelihood of a sustained virological response (SVR) to treatment in subjects infected with hepatitis C virus (HCV). SNPs in the promoters of interleukin (IL)-10 (-1082 A/G, rs1800896), myxovirus resistance protein 1 (-123 C/A, rs17000900 and -88 G/T, rs2071430) and tumour necrosis factor (TNF) (-308 G/A, rs1800629 and -238 G/A, rs361525) genes and the outcome of PEGylated α-interferon plus ribavirin therapy were investigated. This analysis was performed in 114 Brazilian, HCV genotype 1-infected patients who had a SVR and in 85 non-responders and 64 relapsers. A significantly increased risk of having a null virological response was observed in patients carrying at least one A allele at positions -308 [odds ratios (OR) = 2.58, 95% confidence intervals (CI) = 1.44-4.63, p = 0.001] or -238 (OR = 7.33, 95% CI = 3.59-14.93, p < 0.001) in the TNF promoter. The risk of relapsing was also elevated (-308: OR = 2.87, 95% CI = 1.51-5.44, p = 0.001; -238: OR = 4.20, 95% CI = 1.93-9.10, p < 0.001). Multiple logistic regression of TNF diplotypes showed that patients with at least two copies of the A allele had an even higher risk of having a null virological response (OR = 16.43, 95% CI = 5.70-47.34, p < 0.001) or relapsing (OR = 6.71, 95% CI = 2.18-20.66, p = 0.001). No statistically significant association was found between the other SNPs under study and anti-HCV therapy response.
Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antivirais/administração & dosagem , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/administração & dosagem , Regiões Promotoras Genéticas , Ribavirina/administração & dosagem , Fator de Necrose Tumoral alfa/genética , Quimioterapia Combinada , Genótipo , Hepatite C Crônica/genética , /genética , Proteínas de Resistência a Myxovirus/genética , Polimorfismo de Nucleotídeo Único , Falha de Tratamento , Carga ViralRESUMO
Certain host single nucleotide polymorphisms (SNPs) affect the likelihood of a sustained virological response (SVR) to treatment in subjects infected with hepatitis C virus (HCV). SNPs in the promoters of interleukin (IL)-10 (-1082 A/G, rs1800896), myxovirus resistance protein 1 (-123 C/A, rs17000900 and -88 G/T, rs2071430) and tumour necrosis factor (TNF) (-308 G/A, rs1800629 and -238 G/A, rs361525) genes and the outcome of PEGylated α-interferon plus ribavirin therapy were investigated. This analysis was performed in 114 Brazilian, HCV genotype 1-infected patients who had a SVR and in 85 non-responders and 64 relapsers. A significantly increased risk of having a null virological response was observed in patients carrying at least one A allele at positions -308 [odds ratios (OR) = 2.58, 95% confidence intervals (CI) = 1.44-4.63, p = 0.001] or -238 (OR = 7.33, 95% CI = 3.59-14.93, p < 0.001) in the TNF promoter. The risk of relapsing was also elevated (-308: OR = 2.87, 95% CI = 1.51-5.44, p = 0.001; -238: OR = 4.20, 95% CI = 1.93-9.10, p < 0.001). Multiple logistic regression of TNF diplotypes showed that patients with at least two copies of the A allele had an even higher risk of having a null virological response (OR = 16.43, 95% CI = 5.70-47.34, p < 0.001) or relapsing (OR = 6.71, 95% CI = 2.18-20.66, p = 0.001). No statistically significant association was found between the other SNPs under study and anti-HCV therapy response.
Assuntos
Antivirais/administração & dosagem , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/administração & dosagem , Regiões Promotoras Genéticas , Ribavirina/administração & dosagem , Fator de Necrose Tumoral alfa/genética , Quimioterapia Combinada , Feminino , Genótipo , Hepatite C Crônica/genética , Humanos , Interleucina-10/genética , Masculino , Pessoa de Meia-Idade , Proteínas de Resistência a Myxovirus/genética , Polimorfismo de Nucleotídeo Único , Falha de Tratamento , Carga ViralRESUMO
OBJECTIVES: Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. METHOD: Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. RESULTS: We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (p<0.0001). The C/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. CONCLUSION: Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 genes. The combined analysis of the suppressor of cytokine signaling 3 and IL28B genotypes more effectively predicted sustained virologic response than IL28B analysis alone.
Assuntos
Hepatite C Crônica/tratamento farmacológico , Interleucinas/genética , Proteínas de Resistência a Myxovirus/genética , Osteopontina/genética , Polimorfismo Genético/genética , Proteínas Supressoras da Sinalização de Citocina/genética , Adulto , Antivirais/uso terapêutico , Feminino , Frequência do Gene , Marcadores Genéticos , Genótipo , Hepacivirus/efeitos dos fármacos , Humanos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Interferons , Masculino , Pessoa de Meia-Idade , Proteínas de Resistência a Myxovirus/efeitos dos fármacos , Osteopontina/efeitos dos fármacos , Polietilenoglicóis/uso terapêutico , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/uso terapêutico , Ribavirina/uso terapêutico , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/efeitos dos fármacos , Resultado do TratamentoRESUMO
OBJECTIVES: Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. METHOD: Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. RESULTS: We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (p<0.0001). The C/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. CONCLUSION: Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus ...