scholarly journals Subclinical Infection of Macaques and Baboons with A Baboon Simarterivirus

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 701 ◽  
Author(s):  
Connor Buechler ◽  
Matthew Semler ◽  
David Baker ◽  
Christina Newman ◽  
Joseph Cornish ◽  
...  

Simarteriviruses (Arteriviridae: Simarterivirinae) are commonly found at high titers in the blood of African monkeys but do not cause overt disease in these hosts. In contrast, simarteriviruses cause severe disease in Asian macaques upon accidental or experimental transmission. Here, we sought to better understand the host-dependent drivers of simarterivirus pathogenesis by infecting olive baboons (n = 4) and rhesus monkeys (n = 4) with the simarterivirus Southwest baboon virus 1 (SWBV-1). Surprisingly, none of the animals in our study showed signs of disease following SWBV-1 inoculation. Three animals (two rhesus monkeys and one olive baboon) became infected and sustained high levels of SWBV-1 viremia for the duration of the study. The course of SWBV-1 infection was highly predictable: plasma viremia peaked between 1 × 107 and 1 × 108 vRNA copies/mL at 3–10 days post-inoculation, which was followed by a relative nadir and then establishment of a stable set-point between 1 × 106 and 1 × 107 vRNA copies/mL for the remainder of the study (56 days). We characterized cellular and antibody responses to SWBV-1 infection in these animals, demonstrating that macaques and baboons mount similar responses to SWBV-1 infection, yet these responses are ineffective at clearing SWBV-1 infection. SWBV-1 sequencing revealed the accumulation of non-synonymous mutations in a region of the genome that corresponds to an immunodominant epitope in the simarterivirus major envelope glycoprotein GP5, which likely contribute to viral persistence by enabling escape from host antibodies.

2018 ◽  
Author(s):  
Connor Buechler ◽  
Matthew Semler ◽  
David A. Baker ◽  
Christina Newman ◽  
Joseph P. Cornish ◽  
...  

AbstractSimarteviruses (Arteriviridae:Simartevirus) are commonly found at high titers in the blood of African monkeys but do not cause overt disease in these hosts. In contrast, simarteviruses cause severe disease in Asian macaques upon accidental or experimental transmission. Here, we sought to better understand the host-dependent drivers of simartevirus pathogenesis by infecting olive baboons (n=4) and rhesus macaques (n=4) with the simartevirus Southwest baboon virus 1 (SWBV-1). Surprisingly, none of the animals in our study showed signs of disease following SWBV-1 inoculation. Three animals (two rhesus monkeys and one olive baboon) became infected and sustained high levels of SWBV-1 viremia for the duration of the study. The course of SWBV-1 infection was highly predictable: plasma viremia peaked between 1×107and 1×108vRNA copies/ml at 3–10 days post-inoculation, which was followed by a relative nadir and then establishment of a stable set-point between 1×106and 1×107vRNA copies/ml for the remainder of the study (56 days). We characterized cellular and antibody responses to SWBV-1 infection in these animals, demonstrating that macaques and baboons mount similar responses to SWBV-1 infection, yet these responses are ineffective at clearing SWBV-1 infection. SWBV-1 sequencing revealed the accumulation of non-synonymous mutations in a region of the genome that corresponds to an immunodominant epitope in the simartevirus major envelope glycoprotein GP5, which likely contribute to viral persistence by enabling escape from host antibodies.One Sentence SummarySimartevirus infection has multiple disease manifestations following cross-species transmission.Accessible Summary/ImportanceSimarteviruses are known to infect African monkeys, such as olive baboons, without causing overt disease. In contrast, accidental infection of Asian monkeys, such as rhesus monkeys, has resulted in severe and often fatal disease. We used a simartevirus found circulating among captive olive baboons (Southwest baboon virus 1; SWBV-1) to experimentally infect both olive baboons and rhesus monkeys to model infection with the same virus in both natural and non-natural hosts. Surprisingly, neither baboons nor macaques displayed any laboratory abnormalities or signs of disease over the course of infection, despite robust SWBV-1 replication. In the accompanying study by Cornish et al., a similar experimental approach was undertaken: African patas monkeys and rhesus monkeys were infected with the simartevirus simian hemorrhagic fever virus (SHFV). In contrast to our study, SHFV caused disease in both of these hosts, albeit with much more severe disease developing in the macaques. Interestingly, we observed similar levels of immune cell activation in simartevirus-infected animals across both studies, suggesting that finer nuances of the host response, and perhaps properties of each individual simartevirus, may influences pathogenicity of these viruses in primates. Taken together, our collective findings highlight the wide clinical spectrum of simartevirus infection, ranging from highly-lethal hemorrhagic disease to persistent infection without any overt signs of disease, even in non-natural primate hosts.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Robert W. Cross ◽  
Zachary A. Bornholdt ◽  
Abhishek N. Prasad ◽  
Viktoriya Borisevich ◽  
Krystle N. Agans ◽  
...  

AbstractMonoclonal antibodies (mAbs) and remdesivir, a small-molecule antiviral, are promising monotherapies for many viruses, including members of the genera Marburgvirus and Ebolavirus (family Filoviridae), and more recently, SARS-CoV-2. One of the major challenges of acute viral infections is the treatment of advanced disease. Thus, extending the window of therapeutic intervention is critical. Here, we explore the benefit of combination therapy with a mAb and remdesivir in a non-human primate model of Marburg virus (MARV) disease. While rhesus monkeys are protected against lethal infection when treatment with either a human mAb (MR186-YTE; 100%), or remdesivir (80%), is initiated 5 days post-inoculation (dpi) with MARV, no animals survive when either treatment is initiated alone beginning 6 dpi. However, by combining MR186-YTE with remdesivir beginning 6 dpi, significant protection (80%) is achieved, thereby extending the therapeutic window. These results suggest value in exploring combination therapy in patients presenting with advanced filovirus disease.


2018 ◽  
Author(s):  
Joseph P. Cornish ◽  
Ian N. Moore ◽  
Donna L. Perry ◽  
Abigail Lara ◽  
Mahnaz Minai ◽  
...  

ABSTRACTSimian hemorrhagic fever virus (SHFV) causes a fulminant and typically lethal viral hemorrhagic fever (VHF) in macaques (Cercopithecinae: Macaca spp.) but causes subclinical infections in patas monkeys (Cercopithecinae: Erythrocebus patas). This difference in disease course offers a unique opportunity to compare host-responses to infection by a VHF-causing virus in biologically similar susceptible and refractory animals. Patas and rhesus monkeys were inoculated side-by-side with SHFV. In contrast to the severe disease observed in rhesus monkeys, patas monkeys developed a limited clinical disease characterized by changes in complete blood counts, serum chemistries, and development of lymphadenopathy. Viremia was measurable 2 days after exposure and its duration varied by species. Infectious virus was detected in terminal tissues of both patas and rhesus monkeys. Varying degrees of overlap in changes in serum concentrations of IFN-γ, MCP-1, and IL-6 were observed between patas and rhesus monkeys, suggesting the presence of common and species-specific cytokine responses to infection. Similarly, quantitative immunohistochemistry of terminal livers and whole blood flow cytometry revealed varying degrees of overlap in changes in macrophages, natural killer cells, and T-cells. The unexpected degree of overlap in host-response suggests that relatively small subsets of a host’s response to infection may be responsible for driving pathogenesis that results in a hemorrhagic fever. Furthermore, comparative SHFV infection in patas and rhesus monkeys offers an experimental model to characterize host-response mechanisms associated with viral hemorrhagic fever and evaluate pan-viral hemorrhagic fever countermeasures.IMPORTANCEHost-response mechanisms involved in pathogenesis of VHFs remain poorly understood. An underlying challenge is separating beneficial, inconsequential, and detrimental host-responses during infection. The comparison of host-responses to infection with the same virus in biologically similar animals that have drastically different disease manifestations allows for the identification of pathogenic mechanisms. SHFV, a surrogate virus for human VHF-causing viruses likely causes subclinical infection in African monkeys such as patas monkeys but can cause severe disease in Asian macaque monkeys. Data from the accompanying article by Buechler et al. support that infection of macaques and baboons with non-SHFV simarteviruses can establish persistent or long-term subclinical infections. Baboons, macaques, and patas monkeys are relatively closely taxonomically related (Cercopithecidae: Cercopithecinae) and therefore offer a unique opportunity to dissect how host-response differences determine disease outcome in VHFs.


2020 ◽  
Vol 57 (4) ◽  
Author(s):  
Katja Ester ◽  
William Lauman Ragland

Immunosuppressive viruses cause substantial economic losses to the poultry industry. Chicken anaemia virus (CAV) causes severe disease in young chickens, whereas subclinical infection in older birds causes immunosuppression. In this study, we addressed the ability of CAV to interfere with production of antimicrobial molecule nitric oxide (NO) by macrophages. NO production in chicken macrophage cell line HD11 was induced using both Toll-like receptor 4 agonist, bacterial lipopolysaccharide, and an immune modulator, interferon-γ. In addition, we treated macrophages with CAV propagated in chicken lymphoblastoid cells. The levels of NO were measured by the Griess reaction. Addition of CAV decreased both the interferon-γ and the lipopolysaccharide associated induction of NO. Observed effect was not caused by CAV-related cytotoxicity, as no decrease in number of viable cells was observed. Although CAV could not completely abrogate NO production, attenuation of NO induction was clearly present. We have previously shown that CAV interferes with the expression of interferons in chickens during subclinical infection. Since the signalling pathways of expression of interferons and type 2 nitric oxide synthase, enzyme involved in NO formation, overlap, we conclude that measured decrease in NO levels is a consequence of CAV interference with interferon and NO synthase signalling. Regardless of the fact whether the attenuation of NO serves as a viral primary defence, or is only a secondary effect, it could impair the immune response to other pathogens and contribute to the global immunosuppression in chicken houses.Key words: chicken; immunosuppression; chicken anaemia virus (CAV); macrophage; nitric oxide (NO) VIRUS PIŠČANČJE ANEMIJE VPLIVA NA PROIZVODNJO DUŠIKOVIH OKSIDOV V MAKROFAGIH PIŠČANEV HD11 Povzetek: Imunosupresivni virusi povzročajo velike gospodarske izgube v perutninski industriji. Virus piščančje anemije (CAV) pri mladih piščancih povzroča hudo bolezen, medtem ko subklinična okužba pri starejših pticah povzroča oslabljen imunski odziv. V tej raziskavi je bil spremljan vpliv CAV na proizvodnjo dušikovih oksidov (NO) v makrofagih. Proizvodnja NO v piščančjih makrofagih v celični liniji HD11 je bila sprožena z uporabo agonista Toll-u podobnega receptorja 4, bakterijskega lipopolisaharida in imunskega modulatorja interferona-γ, makrofagi pa so bili okuženi s CAV, razmnoženim v piščančjih limfoblastoidnih celicah. Ravni NO so izmerili po Griessovi reakciji. Prisotnost CAV je zmanjšala proizvodnjo NO, spodbujeno tako z interferonom-γ, kot z lipopolisaharidom. Opaženega učinka ni povzročila citotoksičnost, povezana s CAV, saj ni bilo opaziti zmanjšanja števila živih celic. Čeprav CAV ni popolnoma zavrla nastajanja NO, je bilo očitno prisotno zmanjšanje nastajanja NO. Pred tem so pokazali, da CAV moti izražanje interferonov pri piščancih med subklinično okužbo. Ker se poti znotrajceličnega prenosa urejanja izražanja interferonov in sintaze dušikovih oksidov tipa 2, encima, ki sodeluje pri tvorbi NO, prekrivajo, predvidevamo, da je izmerjeno znižanje ravni NO posledica motenj CAV pri znotrajceličnem prenosu sporočila interferona do sintaze dušikovih oksidov. Ne glede na to, ali zaviranje nastajanja NO služi kot primarna virusna obramba ali je le sekundarni učinek, lahko poslabša imunski odziv na druge patogene in prispeva k splošnemu zmanjšanju imunskega odziva v kurnikih ali na kokošjih farmah.Ključne besede: piščanci; zmanjšanje imunskega odziva; virus piščančje anemije (CAV); makrofagi; dušikov oksid (NO)


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Joseph Cornish ◽  
Ian Moore ◽  
Donna Perry ◽  
Abigail Lara ◽  
Mahnaz Minai ◽  
...  

Simian hemorrhagic fever virus (SHFV) causes a fulminant and typically lethal viral hemorrhagic fever (VHF) in macaques (Cercopithecinae: Macaca spp.) but causes subclinical infections in patas monkeys (Cercopithecinae: Erythrocebus patas). This difference in disease course offers a unique opportunity to compare host responses to infection by a VHF-causing virus in biologically similar susceptible and refractory animals. Patas and rhesus monkeys were inoculated side-by-side with SHFV. Unlike the severe disease observed in rhesus monkeys, patas monkeys developed a limited clinical disease characterized by changes in complete blood counts, serum chemistries, and development of lymphadenopathy. Viral RNA was measurable in circulating blood 2 days after exposure, and its duration varied by species. Infectious virus was detected in terminal tissues of both patas and rhesus monkeys. Varying degrees of overlap in changes in serum concentrations of interferon (IFN)-γ, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 were observed between patas and rhesus monkeys, suggesting the presence of common and species-specific cytokine responses to infection. Similarly, quantitative immunohistochemistry of livers from terminal monkeys and whole blood flow cytometry revealed varying degrees of overlap in changes in macrophages, natural killer cells, and T-cells. The unexpected degree of overlap in host response suggests that relatively small subsets of a host’s response to infection may be responsible for driving hemorrhagic fever pathogenesis. Furthermore, comparative SHFV infection in patas and rhesus monkeys offers an experimental model to characterize host–response mechanisms associated with viral hemorrhagic fever and evaluate pan-viral hemorrhagic fever countermeasures.


2020 ◽  
pp. 1198-1204
Author(s):  
Nicholas P.J. Day

Leptospirosis, caused by pathogenic spirochetes of the genus Leptospira, is a bacterial zoonosis with a worldwide impact on human and animal health. For human infection rodents are the most important reservoir; infection follows exposure to contaminated water, soil, or urine, the organism entering through skin abrasions or mucosal surfaces. Subclinical infection is common, but symptomatic disease usually begins with abrupt onset of fever, chills, headache, and myalgia. Most cases are undiagnosed due to the poor availability of diagnostic tests in regions where transmission occurs. Whether treatment of mild leptospirosis with antibiotics prevents more severe disease remains controversial, most experts recommend empirical treatment if leptospirosis is suspected.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 741
Author(s):  
John F. Murphy ◽  
H. Tucker Hallmark ◽  
Thiruvarangan Ramaraj ◽  
Anitha Sundararajan ◽  
Faye Schilkey ◽  
...  

Tobacco etch virus (TEV; genus Potyvirus) is flexuous rod shaped with a single molecule of single-stranded RNA and causes serious yield losses in species in the Solanaceae. Three TEV strains (HAT, Mex21, and N) are genetically distinct and cause different disease symptoms in plants. Here, a transcriptomic RNA sequencing approach was taken for each TEV strain to evaluate gene expression of the apical stem segment of pepper plants during two stages of disease development. Distinct profiles of Differentially Expressed Genes (DEGs) were identified for each TEV strain. DEG numbers increased with degree of symptom severity: 24 from HAT, 1190 from Mex21, and 4010 from N. At 7 days post-inoculation (dpi), when systemic symptoms were similar, there were few DEGs for HAT- and Mex21-infected plants, whereas N-infected plants had 2516 DEGs. DEG patterns from 7 to 14 dpi corresponded to severity of disease symptoms: milder disease with smaller DEG changes for HAT and Mex21 and severe disease with larger DEG changes for N. Strikingly, in each of these comparisons, there are very few overlapping DEGs among the TEV strains, including no overlapping DEGs between all three strains at 7 or 14 dpi.


2017 ◽  
Author(s):  
Maja Križnik ◽  
Marko Petek ◽  
David Dobnik ◽  
Živa Ramšak ◽  
Špela Baebler ◽  
...  

AbstractPotato virus Y is the most economically important potato viral pathogen. We aimed at unraveling the roles of small RNAs (sRNAs) in the complex immune signaling network controlling the establishment of tolerant response of potato cv. Désirée to the virus. We constructed a sRNA regulatory network connecting sRNAs and their targets to link sRNA level responses to physiological processes. We discovered an interesting novel sRNAs-gibberellin regulatory circuit being activated as early as 3 days post inoculation before viral multiplication can be detected. Increased levels of miR167 and phasiRNA931 were reflected in decreased levels of transcripts involved in gibberellin biosynthesis. Moreover, decreased concentration of gibberellin confirmed this regulation. The functional relation between lower activity of gibberellin signaling and reduced disease severity was previously confirmed in Arabidopsis-virus interaction using knockout mutants. We further showed that this regulation is salicylic acid-dependent as the response of sRNA network was attenuated in salicylic acid-depleted transgenic counterpart NahG-Désirée expressing severe disease symptoms. Besides downregulation of gibberellin signaling, regulation of several other parts of sRNA network in tolerant Désirée revealed similarities to responses observed in mutualistic symbiotic interactions. The intertwining of different regulatory networks revealed shows how developmental signaling, disease symptom development and stress signaling can be balanced.


2018 ◽  
Vol 19 (9) ◽  
pp. 2686 ◽  
Author(s):  
Tingting Sun ◽  
Feng Liu ◽  
Wenju Wang ◽  
Ling Wang ◽  
Zhuqing Wang ◽  
...  

Catalases, which consist of multiple structural isoforms, catalyze the decomposition of hydrogen peroxide in cells to prevent membrane lipid peroxidation. In this study, a group II catalase gene ScCAT2 (GenBank Accession No. KF528830) was isolated from sugarcane genotype Yacheng05-179. ScCAT2 encoded a predicted protein of 493 amino acid residues, including a catalase active site signature (FARERIPERVVHARGAS) and a heme-ligand signature (RVFAYADTQ). Subcellular localization experiments showed that the ScCAT2 protein was distributed in the cytoplasm, plasma membrane, and nucleus of Nicotiana benthamiana epidermal cells. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the ScCAT2 gene was ubiquitously expressed in sugarcane tissues, with expression levels from high to low in stem skin, stem pith, roots, buds, and leaves. ScCAT2 mRNA expression was upregulated after treatment with abscisic acid (ABA), sodium chloride (NaCl), polyethylene glycol (PEG), and 4 °C low temperature, but downregulated by salicylic acid (SA), methyl jasmonate (MeJA), and copper chloride (CuCl2). Moreover, tolerance of Escherichia coli Rosetta cells carrying pET-32a-ScCAT2 was enhanced by NaCl stress, but not by CuCl2 stress. Sporisorium scitamineum infection of 10 different sugarcane genotypes showed that except for YZ03-258, FN40, and FN39, ScCAT2 transcript abundance in four smut-resistant cultivars (Yacheng05-179, YZ01-1413, YT96-86, and LC05-136) significantly increased at the early stage (1 day post-inoculation), and was decreased or did not change in the two smut-medium-susceptibility cultivars (ROC22 and GT02-467), and one smut-susceptible cultivar (YZ03-103) from 0 to 3 dpi. Meanwhile, the N. benthamiana leaves that transiently overexpressed ScCAT2 exhibited less severe disease symptoms, more intense 3,3′-diaminobenzidine (DAB) staining, and higher expression levels of tobacco immune-related marker genes than the control after inoculation with tobacco pathogen Ralstonia solanacearum or Fusarium solani var. coeruleum. These results indicate that ScCAT2 plays a positive role in immune responses during plant–pathogen interactions, as well as in salt, drought, and cold stresses.


2020 ◽  
Author(s):  
Elodie Monchatre-Leroy ◽  
Sandrine Lesellier ◽  
Marine Wasniewski ◽  
Evelyne Picard-Meyer ◽  
Céline Richomme ◽  
...  

AbstractUnderstanding the pathogenesis of the SARS-CoV-2 infection is key to develop preventive and therapeutic strategies against COVID-19, in the case of severe illness but also when the disease is mild. The use of appropriate experimental animal models remains central in the in-vivo exploration of the physiopathology of infection and antiviral strategies. This study describes SARS-CoV-2 intra-nasal infection in ferrets and hamsters with low doses of low-passage SARS-CoV-2 clinical French isolate UCN19, describing infection levels, excretion, immune responses and pathological patterns in both animal species. Individual infection with 103 pfu SARS-CoV-2 induced a more severe disease in hamsters than in ferrets. Viral RNA was detected in the lungs of hamsters but not of ferrets and in the brain (olfactive and/or spinal bulbs) of both species. Overall, the clinical disease remained mild, with serological responses detected from 7 days and 10 days post inoculation in hamsters and ferrets respectively. Virus became undetectable and pathology resolved within 14 days. The kinetics and levels of infection can be used in ferrets and hamsters as experimental models for understanding the pathogenicity of SARS-CoV-2, and testing the protective effect of drugs.


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