Interleukin-1- and Type I Interferon-Dependent Enhanced Immunogenicity of an NYVAC-HIV-1 Env-Gag-Pol-Nef Vaccine Vector with Dual Deletions of Type I and Type II Interferon-Binding Proteins

ABSTRACTNYVAC, a highly attenuated, replication-restricted poxvirus, is a safe and immunogenic vaccine vector. Deletion of immune evasion genes from the poxvirus genome is an attractive strategy for improving the immunogenic properties of poxviruses. Using systems biology approaches, we describe herein the enhanced immunological profile of NYVAC vectors expressing the HIV-1 clade Cenv,gag,pol, andnefgenes (NYVAC-C) with single or double deletions of genes encoding type I (ΔB19R) or type II (ΔB8R) interferon (IFN)-binding proteins. Transcriptomic analyses of human monocytes infected with NYVAC-C, NYVAC-C with theB19Rdeletion (NYVAC-C-ΔB19R), or NYVAC-C withB8RandB19Rdeletions (NYVAC-C-ΔB8RB19R) revealed a concerted upregulation of innate immune pathways (IFN-stimulated genes [ISGs]) of increasing magnitude with NYVAC-C-ΔB19R and NYVAC-C-ΔB8RB19R than with NYVAC-C. Deletion ofB8RandB19Rresulted in an enhanced activation of IRF3, IRF7, and STAT1 and the robust production of type I IFNs and of ISGs, whose expression was inhibited by anti-type I IFN antibodies. Interestingly, NYVAC-C-ΔB8RB19R induced the production of much higher levels of proinflammatory cytokines (tumor necrosis factor [TNF], interleukin-6 [IL-6], and IL-8) than NYVAC-C or NYVAC-C-ΔB19R as well as a strong inflammasome response (caspase-1 and IL-1β) in infected monocytes. Top network analyses showed that this broad response mediated by the deletion ofB8RandB19Rwas organized around two upregulated gene expression nodes (TNF and IRF7). Consistent with these findings, monocytes infected with NYVAC-C-ΔB8RB19R induced a stronger type I IFN-dependent and IL-1-dependent allogeneic CD4+T cell response than monocytes infected with NYVAC-C or NYVAC-C-ΔB19R. Dual deletion of type I and type II IFN immune evasion genes in NYVAC markedly enhanced its immunogenic properties via its induction of the increased expression of type I IFNs and IL-1β and make it an attractive candidate HIV vaccine vector.IMPORTANCENYVAC is a replication-deficient poxvirus developed as a vaccine vector against HIV. NYVAC expresses several genes known to impair the host immune defenses by interfering with innate immune receptors, cytokines, or interferons. Given the crucial role played by interferons against viruses, we postulated that targeting the type I and type II decoy receptors used by poxvirus to subvert the host innate immune response would be an attractive approach to improve the immunogenicity of NYVAC vectors. Using systems biology approaches, we report that deletion of type I and type II IFN immune evasion genes in NYVAC poxvirus resulted in the robust expression of type I IFNs and interferon-stimulated genes (ISGs), a strong activation of the inflammasome, and upregulated expression of IL-1β and proinflammatory cytokines. Dual deletion of type I and type II IFN immune evasion genes in NYVAC poxvirus improves its immunogenic profile and makes it an attractive candidate HIV vaccine vector.

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Human Cytomegalovirus DNA Polymerase Subunit UL44 Antagonizes Antiviral Immune Responses by Suppressing IRF3- and NF-κB-Mediated Transcription

Journal of Virology ◽

10.1128/jvi.00181-19 ◽

2019 ◽

Vol 93 (11) ◽

Cited By ~ 9

Author(s):

Yu-Zhi Fu ◽

Shan Su ◽

Hong-Mei Zou ◽

Yi Guo ◽

Su-Yun Wang ◽

...

Keyword(s):

Immune Responses ◽

Dna Polymerase ◽

Inflammatory Cytokines ◽

Immune Evasion ◽

Innate Immune ◽

Transcriptional Level ◽

Type I ◽

Innate Immune Responses ◽

Type I Ifns ◽

Antiviral Genes

ABSTRACT Innate immunity is the first line of host defense against viral invasion. The induction of type I interferons (IFNs) and inflammatory cytokines is essential to host antiviral immune responses, which are also key targets of viral immune evasion. Human cytomegalovirus (HCMV) can establish long-term latent infections, in which immune evasion is a pivotal step. In this study, we identified HCMV protein UL44, a DNA polymerase processivity factor, as an inhibitor of the interferon regulatory factor 3 (IRF3)- and NF-κB-dependent antiviral response. Ectopic expression of UL44 inhibited HCMV-triggered induction of downstream effector genes and enhanced viral replication. Conversely, knockdown of UL44 potentiated HCMV-triggered induction of downstream antiviral genes. UL44 interacted with IRF3 and p65, and it inhibited the binding of IRF3 and NF-κB to the promoters of their downstream antiviral genes. These findings reveal an important mechanism of immune evasion by HCMV at the transcriptional level. IMPORTANCE Induction of type I IFNs and inflammatory cytokines plays pivotal roles in host antiviral innate immune responses. Viruses have evolved various mechanisms to interfere with these processes. HCMV causes severe ailments in immunodeficient populations and is a major cause of birth defects. It has been shown that HCMV antagonizes host innate immune defenses, which is important for establishing immune evasion and latent infection. In this study, we identified the HCMV DNA polymerase subunit UL44 as a suppressor of antiviral innate immune responses. Overexpression of UL44 impaired HCMV-triggered induction of type I IFNs and other antiviral genes and thus potentiated viral replication, whereas UL44 deficiency showed opposite effects. Mechanistic studies indicated that UL44 acts by inhibiting the binding of IRF3 and NF-κB to the promoters of downstream antiviral genes. These findings defined an important mechanism of HCMV immune evasion at the transcriptional level, which may provide a therapeutic target for the treatment of HCMV infection.

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Intron-containing RNA from the HIV-1 provirus activates type I interferon and inflammatory cytokines

10.1101/128447 ◽

2017 ◽

Author(s):

Sean Matthew McCauley ◽

Kyusik Kim ◽

Anetta Nowosielska ◽

Ann Dauphin ◽

Leonid Yurkovetskiy ◽

...

Keyword(s):

T Cells ◽

Antiviral Therapy ◽

Antiviral Drug ◽

Cell Types ◽

Innate Immune ◽

Type I ◽

Infected People ◽

Innate Immune Signaling ◽

Post Transcriptional Regulation ◽

Hiv 1

ABSTRACTHIV-1-infected people who take drugs that suppress viremia to undetectable levels are protected from developing AIDS. Nonetheless, these individuals have chronic inflammation associated with heightened risk of cardiovascular pathology. HIV-1 establishes proviruses in long-lived CD4+memory T cells, and perhaps other cell types, that preclude elimination of the virus even after years of continuous antiviral therapy. Though the majority of proviruses that persist during antiviral therapy are defective for production of infectious virions, many are expressed, raising the possibility that the HIV-1provirus or its transcripts contribute to ongoing inflammation. Here we found that the HIV-1 provirus activated innate immune signaling in isolated dendritic cells, macrophages, and CD4+T cells. Immune activation required transcription from the HIV-1 provirus and expression of CRM1-dependent, Rev-dependent, RRE-containing, unspliced HIV-1 RNA. Ifrevwas providedin trans, all HIV-1 coding sequences were dispensable for activation except thosecis-acting sequences required for replication or splicing. These results indicate that the complex, post-transcriptional regulation intrinsic to HIV-1 RNA is detected by the innate immune system as a danger signal, and that drugs which disrupt HIV-1 transcription or HIV-1 RNA metabolism would add qualitative benefit to current antiviral drug regimens.

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Arterivirus nsp4 Antagonizes Interferon Beta Production by Proteolytically Cleaving NEMO at Multiple Sites

Journal of Virology ◽

10.1128/jvi.00385-19 ◽

2019 ◽

Vol 93 (12) ◽

Cited By ~ 7

Author(s):

Jiyao Chen ◽

Dang Wang ◽

Zheng Sun ◽

Li Gao ◽

Xinyu Zhu ◽

...

Keyword(s):

Immune Evasion ◽

Interferon Beta ◽

Substrate Recognition ◽

Innate Immune ◽

Equine Arteritis Virus ◽

Single Site ◽

Respiratory Syndrome Virus ◽

Type I ◽

Type I Ifn ◽

Recognition Mechanism

ABSTRACTEquine arteritis virus (EAV) and porcine reproductive and respiratory syndrome virus (PRRSV) represent two members of the familyArteriviridaeand pose major threats for the horse- and swine-breeding industries worldwide. A previous study suggested that PRRSV nsp4, a 3C-like protease, antagonizes interferon beta (IFN-β) production by cleaving the NF-κB essential modulator (NEMO) at a single site, glutamate 349 (E349). Here, we demonstrated that EAV nsp4 also inhibited virus-induced IFN-β production by targeting NEMO for proteolytic cleavage and that the scission occurred at four sites: E166, E171, glutamine 205 (Q205), and E349. Additionally, we found that, besides the previously reported cleavage site E349 in NEMO, scission by PRRSV nsp4 took place at two additional sites, E166 and E171. These results imply that while cleaving NEMO is a common strategy utilized by EAV and PRRSV nsp4 to antagonize IFN induction, EAV nsp4 adopts a more complex substrate recognition mechanism to target NEMO. By analyzing the abilities of the eight different NEMO fragments resulting from EAV or PRRSV nsp4 scission to induce IFN-β production, we serendipitously found that a NEMO fragment (residues 1 to 349) could activate IFN-β transcription more robustly than full-length NEMO, whereas all other NEMO cleavage products were abrogated for the IFN-β-inducing capacity. Thus, NEMO cleavage at E349 alone may not be sufficient to completely inactivate the IFN response via this signaling adaptor. Altogether, our findings suggest that EAV and PRRSV nsp4 cleave NEMO at multiple sites and that this strategy is critical for disarming the innate immune response for viral survival.IMPORTANCEThe arterivirus nsp4-encoded 3C-like protease (3CLpro) plays an important role in virus replication and immune evasion, making it an attractive target for antiviral therapeutics. Previous work suggested that PRRSV nsp4 suppresses type I IFN production by cleaving NEMO at a single site. In contrast, the present study demonstrates that both EAV and PRRSV nsp4 cleave NEMO at multiple sites and that this strategy is essential for disruption of type I IFN production. Moreover, we reveal that EAV nsp4 also cleaves NEMO at glutamine 205 (Q205), which is not targeted by PRRSV nsp4. Notably, targeting a glutamine in NEMO for cleavage has been observed only with picornavirus 3C proteases (3Cpro) and coronavirus 3CLpro. In aggregate, our work expands knowledge of the innate immune evasion mechanisms associated with NEMO cleavage by arterivirus nsp4 and describes a novel substrate recognition characteristic of EAV nsp4.

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Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

Journal of Virology ◽

10.1128/jvi.02749-15 ◽

2015 ◽

Vol 90 (5) ◽

pp. 2403-2417 ◽

Cited By ~ 41

Author(s):

Chuan Xia ◽

Madhuvanthi Vijayan ◽

Curtis J. Pritzl ◽

Serge Y. Fuchs ◽

Adrian B. McDermott ◽

...

Keyword(s):

Signaling Pathway ◽

Influenza A Virus ◽

Influenza A ◽

Type I Interferon ◽

Innate Immune ◽

Host Cells ◽

Type I ◽

Type I Ifn ◽

Type I Ifns ◽

Ha Protein

ABSTRACTInfluenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity.IMPORTANCEInfluenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling pathway. Here, we uncovered that influenza viral hemagglutinin (HA) protein causes the degradation of type I IFN receptor subunit 1 (IFNAR1). HA promoted phosphorylation and polyubiquitination of IFNAR1, which facilitated the degradation of this receptor. The HA-mediated elimination of IFNAR1 notably decreased the cells' sensitivities to type I IFNs, as demonstrated by the diminished expression of IFN-induced antiviral genes. This discovery could help us understand how IAV regulates the host innate immune response to create an environment optimized for viral survival in host cells.

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SAMHD1 Phosphorylation Coordinates the Anti-HIV-1 Response by Diverse Interferons and Tyrosine Kinase Inhibition

mBio ◽

10.1128/mbio.00819-18 ◽

2018 ◽

Vol 9 (3) ◽

Cited By ~ 15

Author(s):

Matthew A. Szaniawski ◽

Adam M. Spivak ◽

James E. Cox ◽

Jonathan L. Catrow ◽

Timothy Hanley ◽

...

Keyword(s):

Tyrosine Kinase ◽

Tyrosine Kinase Inhibitors ◽

Kinase Inhibitors ◽

Restriction Factor ◽

Type I ◽

Dependent Manner ◽

Type Ii ◽

Type Iii ◽

Type Iii Ifn ◽

Hiv 1

ABSTRACTMacrophages are susceptible to human immunodeficiency virus type 1 (HIV-1) infection despite abundant expression of antiviral proteins. Perhaps the most important antiviral protein is the restriction factor sterile alpha motif domain and histidine/aspartic acid domain-containing protein 1 (SAMHD1). We investigated the role of SAMHD1 and its phospho-dependent regulation in the context of HIV-1 infection in primary human monocyte-derived macrophages and the ability of various interferons (IFNs) and pharmacologic agents to modulate SAMHD1. Here we show that stimulation by type I, type II, and to a lesser degree, type III interferons share activation of SAMHD1 via dephosphorylation at threonine-592 as a consequence of signaling. Cyclin-dependent kinase 1 (CDK1), a known effector kinase for SAMHD1, was downregulated at the protein level by all IFN types tested. Pharmacologic inhibition or small interfering RNA (siRNA)-mediated knockdown of CDK1 phenocopied the effects of IFN on SAMHD1. A panel of FDA-approved tyrosine kinase inhibitors potently induced activation of SAMHD1 and subsequent HIV-1 inhibition. The viral restriction imposed via IFNs or dasatinib could be overcome through depletion of SAMHD1, indicating that their effects are exerted primarily through this pathway. Our results demonstrate that SAMHD1 activation, but not transcriptional upregulation or protein induction, is the predominant mechanism of HIV-1 restriction induced by type I, type II, and type III IFN signaling in macrophages. Furthermore, SAMHD1 activation presents a pharmacologically actionable target through which HIV-1 infection can be subverted.IMPORTANCEOur experimental results demonstrate that SAMHD1 dephosphorylation at threonine-592 represents a central mechanism of HIV-1 restriction that is common to the three known families of IFNs. While IFN types I and II were potent inhibitors of HIV-1, type III IFN showed modest to undetectable activity. Regulation of SAMHD1 by IFNs involved changes in phosphorylation status but not in protein levels. Phosphorylation of SAMHD1 in macrophages occurred at least in part via CDK1. Tyrosine kinase inhibitors similarly induced SAMHD1 dephosphorylation, which protects macrophages from HIV-1 in a SAMHD1-dependent manner. SAMHD1 is a critical restriction factor regulating HIV-1 infection of macrophages.

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Herpes Simplex Virus 1 UL36USP Antagonizes Type I Interferon-Mediated Antiviral Innate Immunity

Journal of Virology ◽

10.1128/jvi.01161-18 ◽

2018 ◽

Vol 92 (19) ◽

Cited By ~ 14

Author(s):

Hui Yuan ◽

Jia You ◽

Hongjuan You ◽

Chunfu Zheng

Keyword(s):

Innate Immune ◽

Type I ◽

Type I Ifn ◽

Herpes Simplex Virus 1 ◽

Type I Ifns ◽

Specific Protease ◽

Ubiquitin Specific Protease ◽

Simplex Virus ◽

Antiviral Innate Immunity ◽

Hsv 1

ABSTRACT Type I interferons (IFNs), as major components of the innate immune system, play a vital role in host resistance to a variety of pathogens. Canonical signaling mediated by type I IFNs activates the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway through binding to the IFN-α/β receptor (IFNAR), resulting in transcription of IFN-stimulated genes (ISGs). However, viruses have evolved multiple strategies to evade this process. Here, we report that herpes simplex virus 1 (HSV-1) ubiquitin-specific protease (UL36USP) abrogates the type I IFN-mediated signaling pathway independent of its deubiquitinase (DUB) activity. In this study, ectopically expressed UL36USP inhibited IFN-β-induced activation of ISRE promoter and transcription of ISGs, and overexpression of UL36USP lacking DUB activity did not influence this effect. Furthermore, UL36USP was demonstrated to antagonize IFN-β-induced activation of JAKs and STATs via specifically binding to the IFNAR2 subunit and blocking the interaction between JAK1 and IFNAR2. More importantly, knockdown of HSV-1 UL36USP restored the formation of JAK1-IFNAR2 complex. These findings underline the roles of UL36USP-IFNAR2 interaction in counteracting the type I IFN-mediated signaling pathway and reveal a novel evasion mechanism of antiviral innate immunity by HSV-1. IMPORTANCE Type I IFNs mediate transcription of numerous antiviral genes, creating a remarkable antiviral state in the host. Viruses have evolved various mechanisms to evade this response. Our results indicated that HSV-1 encodes a ubiquitin-specific protease (UL36USP) as an antagonist to subvert type I IFN-mediated signaling. UL36USP was identified to significantly inhibit IFN-β-induced signaling independent of its deubiquitinase (DUB) activity. The underlying mechanism of UL36USP antagonizing type I IFN-mediated signaling was to specifically bind with IFNAR2 and disassociate JAK1 from IFNAR2. For the first time, we identify UL36USP as a crucial suppressor for HSV-1 to evade type I IFN-mediated signaling. Our findings also provide new insights into the innate immune evasion by HSV-1 and will facilitate our understanding of host-virus interplay.

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Inhibition of Angiogenesis by Type I Interferons in Models of Kaposi'S Sarcoma

The International Journal of Biological Markers ◽

10.1177/172460089901400411 ◽

1999 ◽

Vol 14 (4) ◽

pp. 257-262 ◽

Cited By ~ 11

Author(s):

C. Marchisone ◽

R. Benelli ◽

A. Albini ◽

L. Santi ◽

D. M. Noonan

Keyword(s):

Kaposi's Sarcoma ◽

Kaposi’S Sarcoma ◽

Inhibitory Effect ◽

Type I Interferons ◽

Endothelial Cell Migration ◽

Type I ◽

Type I Ifns ◽

Hiv 1

Kaposi's Sarcoma (KS) is a pathology which occurs with increased frequency and in a particularly aggressive form in AIDS patients. The HIV-1 Tat protein appears to be an important co-factor in the induction of the extensive neo-vascularization associated with AIDS-KS. Tat acts as a chemoattractant for endothelial cells in vitro, inducing both chemotactic and invasive responses. Several clinical trials have been performed testing the effectiveness of diverse biological agents in therapy of KS, among these the type I interferons. Type I IFNs have diverse biological functions besides their anti-viral activity, including anti-angiogenic properties. We have shown that IFNα and IFNβ are potent inhibitors of both primary and immortalized endothelial cell migration and morphogenesis in vitro as well as neo-angiogenesis induced by HIV-1 Tat in vivo. The inhibitory effect of IFN class I on HIV-Tat associated angiogenesis further supports its use as a therapy for epidemic Kaposi's sarcoma. The use of recombinant IFNs at the levels required to obtain a therapeutic effect are associated with side effects and toxicity, therefore we are now developing a gene therapy approach for constant and local delivery type I IFNs.

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Upregulation of BST-2 by Type I Interferons Reduces the Capacity of Vpu To Protect HIV-1-Infected Cells from NK Cell Responses

mBio ◽

10.1128/mbio.01113-19 ◽

2019 ◽

Vol 10 (3) ◽

Cited By ~ 3

Author(s):

Jérémie Prévost ◽

Suzanne Pickering ◽

Mitchell J. Mumby ◽

Halima Medjahed ◽

Gabrielle Gendron-Lepage ◽

...

Keyword(s):

Transmembrane Domain ◽

Nk Cell ◽

Restriction Factor ◽

Type I ◽

Cell Responses ◽

Viral Release ◽

Type I Ifns ◽

Infected Cells ◽

Ifn Treatment ◽

Hiv 1

ABSTRACTThe HIV-1 accessory protein Vpu enhances viral release by counteracting the restriction factor BST-2. Furthermore, Vpu promotes NK cell evasion by downmodulating cell surface NTB-A and PVR, known ligands of the NK cell receptors NTB-A and DNAM-1, respectively. While it has been established that Vpu’s transmembrane domain (TMD) is required for the interaction and intracellular sequestration of BST-2, NTB-A, and PVR, it remains unclear how Vpu manages to target these proteins simultaneously. In this study, we show that upon upregulation, BST-2 is preferentially downregulated by Vpu over its other TMD substrates. We found that type I interferon (IFN)-mediated BST-2 upregulation greatly impairs the ability of Vpu to downregulate NTB-A and PVR. Our results suggest that occupation of Vpu by BST-2 affects its ability to downregulate other TMD substrates. Accordingly, knockdown of BST-2 increases Vpu’s potency to downmodulate NTB-A and PVR in the presence of type I IFN treatment. Moreover, we show that expression of human BST-2, but not that of the macaque orthologue, decreases Vpu’s capacity to downregulate NTB-A. Importantly, we show that type I IFNs efficiently sensitize HIV-1-infected cells to NTB-A- and DNAM-1-mediated direct and antibody-dependent NK cell responses. Altogether, our results reveal that type I IFNs decrease Vpu’s polyfunctionality, thus reducing its capacity to protect HIV-1-infected cells from NK cell responses.IMPORTANCEThe restriction factor BST-2 and the NK cell ligands NTB-A and PVR are among a growing list of membrane proteins found to be downregulated by HIV-1 Vpu. BST-2 antagonism enhances viral release, while NTB-A and PVR downmodulation contributes to NK cell evasion. However, it remains unclear how Vpu can target multiple cellular factors simultaneously. Here we provide evidence that under physiological conditions, BST-2 is preferentially targeted by Vpu over NTB-A and PVR. Specifically, we show that type I IFNs decrease Vpu’s polyfunctionality by upregulating BST-2, thus reducing its capacity to protect HIV-1-infected cells from NK cell responses. This indicates that there is a hierarchy of Vpu substrates upon IFN treatment, revealing that for the virus, targeting BST-2 as part of its resistance to IFN takes precedence over evading NK cell responses. This reveals a potential weakness in HIV-1’s immunoevasion mechanisms that may be exploited therapeutically to harness NK cell responses against HIV-1.

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Interferon type I and type II responses in an Atlantic salmon (Salmo salar) SHK-1 cell line by the salmon TRAITS/SGP microarray

Physiological Genomics ◽

10.1152/physiolgenomics.00064.2007 ◽

2007 ◽

Vol 32 (1) ◽

pp. 33-44 ◽

Cited By ~ 68

Author(s):

S. A. M. Martin ◽

J. B. Taggart ◽

P. Seear ◽

J. E. Bron ◽

R. Talbot ◽

...

Keyword(s):

Atlantic Salmon ◽

Cell Line ◽

Host Response ◽

Transcriptional Response ◽

Pcr Analysis ◽

Type I ◽

Type Ii ◽

Type I Ifns ◽

A Cell ◽

Differential Gene

Interferons (IFNs) are cytokines that have proinflammatory, antiviral, and immunomodulatory effects and play a central role during a host response to pathogens. The IFN family contains both type I and type II molecules. While there are a number of type I IFNs, there is only one type II IFN. Recently both type I and type II IFN genes have been cloned in salmonid fish and recombinant proteins produced showing IFN activity. We have stimulated an Atlantic salmon cell line (SHK-1) with both type I and type II recombinant salmonid IFNs and analyzed the transcriptional response by microarray analysis. Cells were exposed to recombinant IFNs for 6 or 24 h or left unexposed as controls. RNA was hybridized to an Atlantic salmon cDNA microarray (salmon 17K feature TRAITS/SGP array) in order to assess differential gene expression in response to IFN exposure. For IFN I and II, 47 and 72 genes were stimulated, respectively; most genes were stimulated by a single IFN type, but some were affected by both IFNs, indicating coregulation of the IFN response in fish. Real-time PCR analysis was employed to confirm the microarray results for selected differentially expressed genes in both a cell line and primary leukocyte cultures.

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