Heterozygous OAS1 gain-of-function variants cause an autoinflammatory immunodeficiency

Analysis of autoinflammatory and immunodeficiency disorders elucidates human immunity and fosters the development of targeted therapies. Oligoadenylate synthetase 1 is a type I interferon–induced, intracellular double-stranded RNA (dsRNA) sensor that generates 2′-5′-oligoadenylate to activate ribonuclease L (RNase L) as a means of antiviral defense. We identified four de novo heterozygous OAS1 gain-of-function variants in six patients with a polymorphic autoinflammatory immunodeficiency characterized by recurrent fever, dermatitis, inflammatory bowel disease, pulmonary alveolar proteinosis, and hypogammaglobulinemia. To establish causality, we applied genetic, molecular dynamics simulation, biochemical, and cellular functional analyses in heterologous, autologous, and inducible pluripotent stem cell–derived macrophages and/or monocytes and B cells. We found that upon interferon-induced expression, OAS1 variant proteins displayed dsRNA-independent activity, which resulted in RNase L–mediated RNA cleavage, transcriptomic alteration, translational arrest, and dysfunction and apoptosis of monocytes, macrophages, and B cells. RNase L inhibition with curcumin modulated and allogeneic hematopoietic cell transplantation cured the disorder. Together, these data suggest that human OAS1 is a regulator of interferon-induced hyperinflammatory monocyte, macrophage, and B cell pathophysiology.

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OAS1/RNase L executes RIG-I ligand–dependent tumor cell apoptosis

Science Immunology ◽

10.1126/sciimmunol.abe2550 ◽

2021 ◽

Vol 6 (61) ◽

pp. eabe2550

Author(s):

Daniel F. R. Boehmer ◽

Simone Formisano ◽

Carina C. de Oliveira Mann ◽

Stephan A. Mueller ◽

Michael Kluge ◽

...

Keyword(s):

Affinity Purification ◽

Type I Interferons ◽

Type I ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Bona Fide ◽

Translational Arrest ◽

Effector Pathways ◽

Induced Apoptosis ◽

Mediated Priming

Cytoplasmic double-stranded RNA is sensed by RIG-I–like receptors (RLRs), leading to induction of type I interferons (IFN-Is), proinflammatory cytokines, and apoptosis. Here, we elucidate signaling mechanisms that lead to cytokine secretion and cell death induction upon stimulation with the bona fide RIG-I ligand 5′-triphosphate RNA (3p-RNA) in tumor cells. We show that both outcomes are mediated by dsRNA-receptor families with RLR being essential for cytokine production and IFN-I–mediated priming of effector pathways but not for apoptosis. Affinity purification followed by mass spectrometry and subsequent functional analysis revealed that 3p-RNA bound and activated oligoadenylate synthetase 1 and RNase L. RNase L–deficient cells were profoundly impaired in their ability to undergo apoptosis. Mechanistically, the concerted action of translational arrest triggered by RNase L and up-regulation of NOXA was needed to deplete the antiapoptotic MCL-1 to cause intrinsic apoptosis. Thus, 3p-RNA–induced apoptosis is a two-step process consisting of RIG-I–dependent priming and an RNase L–dependent effector phase.

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B cell depletion impairs vaccination-induced CD8+ T cell responses in a type I interferon-dependent manner

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-220435 ◽

2021 ◽

pp. annrheumdis-2021-220435

Author(s):

Theresa Graalmann ◽

Katharina Borst ◽

Himanshu Manchanda ◽

Lea Vaas ◽

Matthias Bruhn ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

B Cell ◽

Cell Expansion ◽

De Novo ◽

T Cell Responses ◽

Type I ◽

Cell Responses ◽

T Cell Expansion

ObjectivesThe monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses.MethodsCD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens.ResultsRituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I.ConclusionsDepending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses.

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Anti-Human Immunodeficiency Virus Activity of Tau Interferon in Human Macrophages: Involvement of Cellular Factors and β-Chemokines

Journal of Virology ◽

10.1128/jvi.77.23.12914-12920.2003 ◽

2003 ◽

Vol 77 (23) ◽

pp. 12914-12920 ◽

Cited By ~ 24

Author(s):

Christine Rogez ◽

Marc Martin ◽

Nathalie Dereuddre-Bosquet ◽

Jacques Martal ◽

Dominique Dormont ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Monocyte ◽

Type I ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Hiv Replication ◽

Human Macrophages ◽

Hiv Rna ◽

Type I Ifns ◽

Immunodeficiency Virus

ABSTRACT Tau interferon (IFN-τ) is a noncytotoxic type I IFN responsible for maternal recognition of the fetus in ruminants. IFN-τ inhibits human immunodeficiency virus (HIV) replication more strongly than human IFN-α, particularly in human monocyte-derived macrophages. In this study performed in human macrophages, IFN-τ efficiently inhibited the early steps of the biological cycle of HIV, decreasing intracellular HIV RNA and inhibiting the initiation of the reverse transcription of viral RNA into proviral DNA. Two mechanisms induced by IFN-τ treatment in macrophages may account for this inhibition: (i) the synthesis of the cellular antiviral factors such as 2′,5′-oligoadenylate synthetase/RNase L and MxA protein and (ii) an increased production of MIP-1α, MIP-1β, and RANTES, which are natural ligands of CCR5, the principal coreceptor of HIV on macrophages. Our results suggest that IFN-τ induces the same antiviral pathways in macrophages as other type I IFNs but without associated toxicity.

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Zika Virus Production Is Resistant to RNase L Antiviral Activity

Journal of Virology ◽

10.1128/jvi.00313-19 ◽

2019 ◽

Vol 93 (16) ◽

Cited By ~ 9

Author(s):

Jillian N. Whelan ◽

Yize Li ◽

Robert H. Silverman ◽

Susan R. Weiss

Keyword(s):

Antiviral Activity ◽

Zika Virus ◽

Viral Genome ◽

Molecular Mechanisms ◽

Virus Production ◽

Type I ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Zikv Infection ◽

Initial Report

SUMMARYThere is currently no knowledge of how the emerging human pathogen Zika virus (ZIKV) interacts with the antiviral endoribonuclease L (RNase L) pathway during infection. Since activation of RNase L during infection typically limits virus production dramatically, we used CRISPR-Cas9 gene editing technology to knockout (KO) targeted host genes involved in the RNase L pathway to evaluate the effects of RNase L on ZIKV infection in human A549 cells. RNase L was activated in response to ZIKV infection, which degraded ZIKV genomic RNA. Surprisingly, despite viral genome reduction, RNase L activity did not reduce ZIKV infectious titers. In contrast, both the flavivirus dengue virus and the alphavirus Sindbis virus replicated to significantly higher titers in RNase L KO cells compared to wild-type (WT) cells. Using MAVS/RNase L double KO cells, we demonstrated that the absence of increased ZIKV production in RNase L KO cells was not due to compensation by enhanced type I interferon transcripts to thus inhibit virus production. Finally, when synthetic double-stranded RNA was detected by OAS3 to induce RNase L antiviral activity prior to ZIKV infection, we observed reduced ZIKV replication factory formation, as well as a 42-fold reduction in virus yield in WT but not RNase L KO cells. This study proposes that ZIKV evades RNase L antiviral activity by generating a viral genome reservoir protected from RNase L cleavage during early infection, allowing for sufficient virus production before RNase L activation is detectable.IMPORTANCEWith the onset of the 2015 ZIKV outbreak, ZIKV pathogenesis has been of extreme global public health interest, and a better understanding of interactions with the host would provide insight into molecular mechanisms driving the severe neurological outcomes of ZIKV disease. Here is the initial report on the relationship between ZIKV and the host oligoadenylate synthetase-RNase L (OAS-RNase L) system, a potent antiviral pathway effective at restricting replication of diverse viruses. Our study elucidated a unique mechanism whereby ZIKV production is impervious to antiviral RNase L activity, through a mechanism of viral RNA protection that is not mimicked during infection with numerous other RNase L-activating viruses, thus identifying a distinct replication strategy potentially important for ZIKV pathogenesis.

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Efficacy of tocilizumab therapy in a patient with severe pancytopenia associated with a STAT3 gain-of-function mutation

BMC Immunology ◽

10.1186/s12865-021-00411-1 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Wenjie Wang ◽

Luyao Liu ◽

Xiaoying Hui ◽

Ying Wang ◽

Wenjing Ying ◽

...

Keyword(s):

T Cells ◽

Next Generation Sequencing ◽

B Cells ◽

Early Onset ◽

De Novo ◽

Gene Sequencing ◽

Immune Dysregulation ◽

Effector Memory ◽

Gain Of Function ◽

Generation Sequencing

Abstract Background We aimed to report the clinical characteristics, immunological features, and treatment of one patient with a de novo STAT3 gain-of-function mutation identified by next generation sequencing. We investigated the efficacy of tocilizumab therapy in immune dysregulation diseases caused by STAT3 mutation. Results The patient was a 16-year-old girl. She presented with recurrent respiratory infections and chronic diarrhea after birth. She had life-threatening autoimmune pancytopenia at 14 years old. After receiving glucocorticoid therapy, she developed diabetes. However, her pancytopenia relapsed when the glucocorticoid was tapered. Next-generation sequencing showed a de novo heterozygous mutation in the STAT3 gene, c.1261G > A (p. G421R), which was previously described as a gain-of-function mutation. After tocilizumab therapy, her pancytopenia fully resolved, and insulin and glucocorticoid therapies were gradually discontinued within 12 months. She had lymphopenia and an inverted CD4/CD8 ratio before therapy. Lymphocyte subpopulation analysis indicated an expansion of effector memory CD4+, effector memory CD8+ and central memory CD4+ T cells. The proportions of memory B cells and naive CD4+ T cells were decreased, and the proportion of naïve B cells was increased. None of the abnormal lymphocytic changes improved significantly. STAT3 GOF mutations were identified by next gene sequencing in those with early-onset multi-organ autoimmunity. Including our patient, 13 patients with STAT3 GOF mutations received targeted treatment. Twelve of them were treated with tocilizumab alone or combination tocilizumab with JAK inhibitor, and ten patients improved. Conclusions Gene sequencing should be performed for patients with early-onset refractory or multiorgan immune dysregulation diseases. Targeted drugs can effectively improve the clinical problems associated with STAT3 gain-of-function mutations, while nontargeted immunosuppressive therapy is usually insufficient.

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ABCE1 Regulates RNase L-Induced Autophagy during Viral Infections

Viruses ◽

10.3390/v13020315 ◽

2021 ◽

Vol 13 (2) ◽

pp. 315

Author(s):

Barkha Ramnani ◽

Praveen Manivannan ◽

Sarah Jaggernauth ◽

Krishnamurthy Malathi

Keyword(s):

Cellular Proliferation ◽

Viral Infections ◽

Antiviral Effect ◽

Host Protein ◽

Type I ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Interferon Stimulated Genes ◽

Antiviral Effects ◽

Increased Activity

Host response to a viral infection includes the production of type I interferon (IFN) and the induction of interferon-stimulated genes that have broad antiviral effects. One of the key antiviral effectors is the IFN-inducible oligoadenylate synthetase/ribonuclease L (OAS/RNase L) pathway, which is activated by double-stranded RNA to synthesize unique oligoadenylates, 2-5A, to activate RNase L. RNase L exerts an antiviral effect by cleaving diverse RNA substrates, limiting viral replication; many viruses have evolved mechanisms to counteract the OAS/RNase L pathway. Here, we show that the ATP-binding cassette E1 (ABCE1) transporter, identified as an inhibitor of RNase L, regulates RNase L activity and RNase L-induced autophagy during viral infections. ABCE1 knockdown cells show increased RNase L activity when activated by 2-5A. Compared to parental cells, the autophagy-inducing activity of RNase L in ABCE1-depleted cells is enhanced with early onset. RNase L activation in ABCE1-depleted cells inhibits cellular proliferation and sensitizes cells to apoptosis. Increased activity of caspase-3 causes premature cleavage of autophagy protein, Beclin-1, promoting a switch from autophagy to apoptosis. ABCE1 regulates autophagy during EMCV infection, and enhanced autophagy in ABCE1 knockdown cells promotes EMCV replication. We identify ABCE1 as a host protein that inhibits the OAS/RNase L pathway by regulating RNase L activity, potentially affecting antiviral effects.

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RNase L Antiviral Activity Is Not a Critical Component of the Oas1b-Mediated Flavivirus Resistance Phenotype

Journal of Virology ◽

10.1128/jvi.00946-19 ◽

2019 ◽

Vol 93 (22) ◽

Author(s):

J. C. Madden ◽

Dan Cui ◽

M. A. Brinton

Keyword(s):

Antiviral Activity ◽

Full Length ◽

Viral Rna ◽

Type I ◽

Mrna Levels ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Resistant Mouse ◽

Resistance Phenotype

ABSTRACT In mice, resistance to central nervous system (CNS) disease induced by members of the genus Flavivirus is conferred by an allele of the 2′-5′ oligoadenylate synthetase 1b gene that encodes the inactive full-length protein (Oas1b-FL). The susceptibility allele encodes a C-terminally truncated protein (Oas1b-tr). We show that the efficiency of neuron infection in the brains of resistant and susceptible mice is similar after an intracranial inoculation of two flaviviruses, but amplification of viral proteins and double-stranded RNA (dsRNA) is inhibited in infected neurons in resistant mouse brains at later times. Active OAS proteins detect cytoplasmic dsRNA and synthesize short 2′-5′-linked oligoadenylates (2′-5′A) that interact with the latent endonuclease RNase L, causing it to dimerize and cleave single-stranded RNAs. To evaluate the contribution of RNase L to the resistance phenotype in vivo, we created a line of resistant RNase L−/− mice. Evidence of RNase L activation in infected RNase L+/+ mice was indicated by higher levels of viral RNA in the brains of infected RNase L−/− mice. Activation of type I interferon (IFN) signaling was detected in both resistant and susceptible brains, but Oas1a and Oas1b mRNA levels were lower in RNase L+/+ mice of both types, suggesting that activated RNase L also has a proflaviviral effect. Inhibition of virus replication was robust in resistant RNase L−/− mice, indicating that activated RNase L is not a critical factor in mediating this phenotype. IMPORTANCE The mouse genome encodes a family of Oas proteins that synthesize 2′-5′A in response to dsRNA. 2′-5′A activates the endonuclease RNase L to cleave single-stranded viral and cellular RNAs. The inactive, full-length Oas1b protein confers flavivirus-specific disease resistance. Although similar numbers of neurons were infected in resistant and susceptible brains after an intracranial virus infection, viral components amplified only in susceptible brains at later times. A line of resistant RNase L−/− mice was used to evaluate the contribution of RNase L to the resistance phenotype in vivo. Activation of RNase L antiviral activity by flavivirus infection was indicated by increased viral RNA levels in the brains of RNase L−/− mice. Oas1a and Oas1b mRNA levels were higher in infected RNase L−/− mice, indicating that activated RNase L also have a proflaviviral affect. However, the resistance phenotype was equally robust in RNase L−/− and RNase L+/+ mice.

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Activation of RNase L by Murine Coronavirus in Myeloid Cells Is Dependent on BasalOasGene Expression and Independent of Virus-Induced Interferon

Journal of Virology ◽

10.1128/jvi.03036-15 ◽

2016 ◽

Vol 90 (6) ◽

pp. 3160-3172 ◽

Cited By ~ 24

Author(s):

L. Dillon Birdwell ◽

Zachary B. Zalinger ◽

Yize Li ◽

Patrick W. Wright ◽

Ruth Elliott ◽

...

Keyword(s):

Gene Expression ◽

Antiviral Activity ◽

Hepatitis Virus ◽

Mouse Hepatitis Virus ◽

Myeloid Cells ◽

Type I ◽

Rnase L ◽

Oligoadenylate Synthetase ◽

Double Stranded Rna ◽

Murine Coronavirus

ABSTRACTThe oligoadenylate synthetase (OAS)-RNase L pathway is a potent interferon (IFN)-induced antiviral activity. Upon sensing double-stranded RNA, OAS produces 2′,5′-oligoadenylates (2-5A), which activate RNase L. Murine coronavirus (mouse hepatitis virus [MHV]) nonstructural protein 2 (ns2) is a 2′,5′-phosphodiesterase (PDE) that cleaves 2-5A, thereby antagonizing RNase L activation. PDE activity is required for robust replication in myeloid cells, as a mutant of MHV (ns2H126R) encoding an inactive PDE fails to antagonize RNase L activation and replicates poorly in bone marrow-derived macrophages (BMM), while ns2H126Rreplicates to high titer in several types of nonmyeloid cells, as well as in IFN receptor-deficient (Ifnar1−/−) BMM. We reported previously that myeloid cells express significantly higher basal levels of OAS transcripts than nonmyeloid cells. Here, we investigated the contributions ofOasgene expression, basal IFN signaling, and virus-induced IFN to RNase L activation. Infection with ns2H126Ractivated RNase L inIfih1−/−BMM to a similar extent as in wild-type (WT) BMM, despite the lack of IFN induction in the absence of MDA5 expression. However, ns2H126Rfailed to induce RNase L activation in BMM treated with IFNAR1-blocking antibody, as well as inIfnar1−/−BMM, both expressing low basal levels ofOasgenes. Thus, activation of RNase L does not require virus-induced IFN but rather correlates with adequate levels of basalOasgene expression, maintained by basal IFN signaling. Finally, overexpression of RNase L is not sufficient to compensate for inadequate basal OAS levels.IMPORTANCEThe oligoadenylate synthetase (OAS)-RNase L pathway is a potent antiviral activity. Activation of RNase L during murine coronavirus (mouse hepatitis virus [MHV]) infection of myeloid cells correlates with high basalOasgene expression and is independent of virus-induced interferon secretion. Thus, our data suggest that cells with high basalOasgene expression levels can activate RNase L and thereby inhibit virus replication early in infection upon exposure to viral double-stranded RNA (dsRNA) before the induction of interferon and prior to transcription of interferon-stimulated antiviral genes. These findings challenge the notion that activation of the OAS-RNase L pathway requires virus to induce type I IFN, which in turn upregulates OAS gene expression, as well as to provide dsRNA to activate OAS. Our data further suggest that myeloid cells may serve as sentinels to restrict viral replication, thus protecting other cell types from infection.

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PKR and RNase L Contribute to Protection against Lethal West Nile Virus Infection by Controlling Early Viral Spread in the Periphery and Replication in Neurons

Journal of Virology ◽

10.1128/jvi.00489-06 ◽

2006 ◽

Vol 80 (14) ◽

pp. 7009-7019 ◽

Cited By ~ 182

Author(s):

Melanie A. Samuel ◽

Kevin Whitby ◽

Brian C. Keller ◽

Anantha Marri ◽

Winfried Barchet ◽

...

Keyword(s):

West Nile Virus ◽

Mortality Rate ◽

Type I ◽

Rnase L ◽

Type I Ifn ◽

Oligoadenylate Synthetase ◽

West Nile ◽

Peripheral Tissues ◽

Viral Spread ◽

Viral Burden

ABSTRACT West Nile virus (WNV) is a neurotropic, mosquito-borne flavivirus that can cause lethal meningoencephalitis. Type I interferon (IFN) plays a critical role in controlling WNV replication, spread, and tropism. In this study, we begin to examine the effector mechanisms by which type I IFN inhibits WNV infection. Mice lacking both the interferon-induced, double-stranded-RNA-activated protein kinase (PKR) and the endoribonuclease of the 2′,5′-oligoadenylate synthetase-RNase L system (PKR−/− × RL−/−) were highly susceptible to subcutaneous WNV infection, with a 90% mortality rate compared to the 30% mortality rate observed in congenic wild-type mice. PKR−/− × RL−/− mice had increased viral loads in their draining lymph nodes, sera, and spleens, which led to early viral entry into the central nervous system (CNS) and higher viral burden in neuronal tissues. Although mice lacking RNase L showed a higher CNS viral burden and an increased mortality, they were less susceptible than the PKR−/− × RL−/− mice; thus, we also infer an antiviral role for PKR in the control of WNV infection. Notably, a deficiency in both PKR and RNase L resulted in a decreased ability of type I IFN to inhibit WNV in primary macrophages and cortical neurons. In contrast, the peripheral neurons of the superior cervical ganglia of PKR−/− × RL−/− mice showed no deficiency in the IFN-mediated inhibition of WNV. Our data suggest that PKR and RNase L contribute to IFN-mediated protection in a cell-restricted manner and control WNV infection in peripheral tissues and some neuronal subtypes.

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Structural Insights into the IL12:IL12 Receptor Complex Assembly by Molecular Modeling, Docking, and Molecular Dynamics Simulation

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666201207113745 ◽

2020 ◽

Vol 23 ◽

Author(s):

Sakshi Singh ◽

Geeta Rai

Keyword(s):

Structure Prediction ◽

Md Simulation ◽

De Novo ◽

3D Structure ◽

Computational Method ◽

Dynamics Simulation ◽

Hematopoietic Progenitor Cell ◽

Interleukin 12 ◽

Type I ◽

Progenitor Cell Proliferation

Background: Interleukin-12 receptor (IL12R) is a type I cytokine receptor that can promote hematopoiesis and regulate innate and adaptive immunity. It binds with the IL12 ligand, which activates the IL-12 signaling pathway that triggers hematopoietic progenitor cell proliferation and differentiation process. The structure of IL12:IL12R complex is not known. Objective: The present work describes a de novo computational method for rational protein designing to elucidate the structure of IL12:IL12R complex. Methods: Homology modeling, docking, and MD simulation methods were used to design mimics of the interaction of IL12 and IL12R. Results: 3D structure prediction and validation confirms the accurate structure of IL12R protein that contains immunoglobin domain, fibronectin type three domain, cytokine-binding domain, and WSXWS motif. Molecular docking and MD simulation revealed that IL12R bound tightly with IL12 ligand at their interface. The estimated binding energy of the docked complex was -26.7 kcal/mol, and the interface area was 281.4 Å2. Hotspot prediction suggested that ARG34, SER58, GLU61, CYS62, LEU63, SER73, ASP142, GLN146, LYS168, THR169 ARG181, ARG183, ARG189, and TYR193 residues in IL12 ligand interacted with SER175, ALA176, CYS177, PRO178, ALA179, ALA180, GLU181, GLU182, ALA192, VAL193, HIS194, ARG208, TYR246, GLN289, ASP290, ARG291, TYR292, TYR293 and SER294 residues in IL12 receptor. Conclusion: The results of the study provides a simulated molecular structure of IL12:IL12R complex that could offer a promising target complex to substantiate IL12 based drug-designing approaches.

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