Lassa virus antigen distribution and inflammation in the ear of infected strain 13/N Guinea pigs

Lassa virus (LASV) is a mammarenavirus (arenavirus) that causes zoonotic infection in humans that can lead to fatal hemorrhagic Lassa fever (LF) disease. Currently, there are no FDA-approved vaccines or therapeutics against LASV. Development of treatments against LF and other related arenavirus-induced hemorrhagic fevers (AHFs) requires relevant animal models that can recapitulate clinical and pathological features of AHF diseases in humans. Laboratory mice are generally resistant to LASV infection, and non-human primates, while being a good animal model for LF, are limited by their high cost. Here, we describe a small, affordable, and convenient animal model that is based on outbred Hartley guinea pigs infected with Pichinde virus (PICV), a mammarenavirus that is non-pathogenic in humans, for use as a surrogate model of human LF. We conducted a detailed analysis of tissue histopathology and immunohistochemical analysis of different organs of outbred Hartley guinea pigs infected with different PICV strains that show differential disease phenotypes and pathologies. Comparing to infection with the avirulent PICV strain (P2 or rP2), animals infected with the virulent strain (P18 or rP18) show extensive pathological changes in different organs that sustain high levels of virus replication. The similarity of tissue pathology and viral antigen distribution between the virulent PICV–guinea pig model and lethal human LASV infection supports a role of this small animal model as a surrogate model of studying human LF in order to understand its pathogenesis and for evaluating potential preventative and therapeutic options against AHFs.

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A Lassa Virus Live-Attenuated Vaccine Candidate Based on Rearrangement of the Intergenic Region

mBio ◽

10.1128/mbio.00186-20 ◽

2020 ◽

Vol 11 (2) ◽

Cited By ~ 3

Author(s):

Yingyun Cai ◽

Masaharu Iwasaki ◽

Daisuke Motooka ◽

David X. Liu ◽

Shuiqing Yu ◽

...

Keyword(s):

Intergenic Region ◽

Guinea Pigs ◽

Cultured Cells ◽

Vaccine Candidate ◽

Lassa Fever ◽

Lassa Virus ◽

Wild Type ◽

Live Attenuated Vaccine ◽

Attenuated Vaccine ◽

Western Africa

ABSTRACT Lassa virus (LASV) poses a significant public health problem within the regions of Lassa fever endemicity in Western Africa. LASV infects several hundred thousand individuals yearly, and a considerable number of Lassa fever cases are associated with high morbidity and lethality. No approved LASV vaccine is available, and current therapy is limited to an off-label usage of ribavirin that is only partially effective and associated with significant side effects. The impact of Lassa fever on human health, together with the limited existing countermeasures, highlights the importance of developing effective vaccines against LASV. Here, we present the development and characterization of a recombinant LASV (rLASV) vaccine candidate [rLASV(IGR/S-S)], which is based on the presence of the noncoding intergenic region (IGR) of the small (S) genome segment (S-IGR) in both large (L) and S LASV segments. In cultured cells, rLASV(IGR/S-S) was modestly less fit than wild-type rLASV (rLASV-WT). rLASV(IGR/S-S) was highly attenuated in guinea pigs, and a single subcutaneous low dose of the virus completely protected against otherwise lethal infection with LASV-WT. Moreover, rLASV(IGR/S-S) was genetically stable during serial passages in cultured cells. These findings indicate that rLASV(IGR/S-S) can be developed into a LASV live-attenuated vaccine (LAV) that has the same antigenic composition as LASV-WT and a well-defined mechanism of attenuation that overcomes concerns about increased virulence that could be caused by genetic changes in the LAV during multiple rounds of multiplication. IMPORTANCE Lassa virus (LASV), the causative agent of Lassa fever, infects several hundred thousand people in Western Africa, resulting in many lethal Lassa fever cases. No U.S. Food and Drug Administration-licensed countermeasures are available to prevent or treat LASV infection. We describe the generation of a novel LASV live-attenuated vaccine candidate rLASV(IGR/S-S), which is based on the replacement of the large genomic segment noncoding intergenic region (IGR) with that of the small genome segment. rLASV(IGR/S-S) is less fit in cell culture than wild-type virus and does not cause clinical signs in inoculated guinea pigs. Importantly, rLASV(IGR/S-S) protects immunized guinea pigs against an otherwise lethal exposure to LASV.

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Diagnosis and Clinical Virology of Lassa Fever as Evaluated by Enzyme-Linked Immunosorbent Assay, Indirect Fluorescent-Antibody Test, and Virus Isolation

Journal of Clinical Microbiology ◽

10.1128/jcm.38.7.2670-2677.2000 ◽

2000 ◽

Vol 38 (7) ◽

pp. 2670-2677 ◽

Cited By ~ 101

Author(s):

D. G. Bausch ◽

P. E. Rollin ◽

A. H. Demby ◽

M. Coulibaly ◽

J. Kanu ◽

...

Keyword(s):

Gold Standard ◽

Virus Isolation ◽

Fluorescent Antibody ◽

Lassa Fever ◽

Virus Antigen ◽

Lassa Virus ◽

Indirect Fluorescent Antibody ◽

Rt Pcr ◽

Prognostic Information ◽

Course Of Illness

The Lassa virus (an arenavirus) is found in West Africa, where it sometimes causes a severe hemorrhagic illness called Lassa fever. Laboratory diagnosis has traditionally been by the indirect fluorescent-antibody (IFA) test. However, enzyme-linked immunosorbent assays (ELISAs) for Lassa virus antigen and immunoglobulin M (IgM) and G (IgG) antibodies have been developed that are thought to be more sensitive and specific. We compared ELISA and IFA testing on sera from 305 suspected cases of Lassa fever by using virus isolation with a positive reverse transcription-PCR (RT-PCR) test as the “gold standard.” Virus isolation and RT-PCR were positive on 50 (16%) of the 305 suspected cases. Taken together, Lassa virus antigen and IgM ELISAs were 88% (95% confidence interval [CI], 77 to 95%) sensitive and 90% (95% CI, 88 to 91%) specific for acute infection. Due to the stringent gold standard used, these likely represent underestimates. Diagnosis could often be made on a single serum specimen. Antigen detection was particularly useful in providing early diagnosis as well as prognostic information. Level of antigenemia varied inversely with survival. Detection by ELISA of IgG antibody early in the course of illness helped rule out acute Lassa virus infection. The presence of IFA during both acute and convalescent stages of infection, as well as significant interobserver variation in reading the slides, made interpretation difficult. However, the assay provided useful prognostic information, the presence of IFA early in the course of illness correlating with death. The high sensitivity and specificity, capability for early diagnosis, and prognostic value of the ELISAs make them the diagnostic tests of choice for the detection of Lassa fever.

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Treatment of Lassa virus infection in outbred guinea pigs with first-in-class human monoclonal antibodies

Antiviral Research ◽

10.1016/j.antiviral.2016.08.012 ◽

2016 ◽

Vol 133 ◽

pp. 218-222 ◽

Cited By ~ 28

Author(s):

Robert W. Cross ◽

Chad E. Mire ◽

Luis M. Branco ◽

Joan B. Geisbert ◽

Megan M. Rowland ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Virus Infection ◽

Guinea Pigs ◽

Lassa Virus ◽

Human Monoclonal Antibodies

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Faculty Opinions recommendation of Temporal progression of lesions in guinea pigs infected with lassa virus.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734888476.793555402 ◽

2019 ◽

Author(s):

Igor Lukashevich

Keyword(s):

Guinea Pigs ◽

Lassa Virus

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Zone electrophoresis of poliovirus partially inactivated by formaldehyde

Epidemiology and Infection ◽

10.1017/s0022172400038560 ◽

1960 ◽

Vol 58 (4) ◽

pp. 419-425 ◽

Cited By ~ 4

Author(s):

A. Polson ◽

J. W. F. Hampton ◽

D. Deeks

Keyword(s):

Electrophoretic Mobility ◽

Guinea Pigs ◽

Virus Antigen ◽

Antigen Concentration ◽

Live Virus ◽

Virus Particles ◽

Antigenic Properties ◽

Main Fraction ◽

Zone Electrophoresis ◽

Main Component

It was shown in this work that the electrophoretic mobility of the MEF1 strain of poliovirus was increased approximately 25% after interrupted inactivation with formaldehyde. This is in accordance with past observations on the behaviour of formaldehyde-treated proteins. The residual live virus had the same mobility as the ‘killed’ virus, thus indicating that the surfaces of all the virus particles have been affected to the same degree by the inactivating agent.Gel precipitin tests performed on the different samples obtained by zone electro-phoresis showed, in addition to the main antigen, the presence of a small amount of a second component of slightly higher mobility, and, as it occurs in the main fraction and the sample thereafter it probably has a slightly higher mobility than the main component.The antigenic properties of the different fractions as shown by the production of antibodies in guinea-pigs correspond with the presence of precipitating antigen in the samples in the region of highest antigen concentration. The faint antigenicities of the fractions obtained from the regions higher up in the zone electrophoresis column are due to small amounts of virus antigen similar to that found in the column on electrophoresis of untreated MEF1 virus, bearing in mind that the inactivated virus was concentrated approximately 2000 times for zone electrophoresis.

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Thioaptamer decoy targeting of AP-1 proteins influences cytokine expression and the outcome of arenavirus infections

Journal of General Virology ◽

10.1099/vir.0.82499-0 ◽

2007 ◽

Vol 88 (3) ◽

pp. 981-990 ◽

Cited By ~ 29

Author(s):

Susan M. Fennewald ◽

Erin P. Scott ◽

Lihong Zhang ◽

Xianbin Yang ◽

Judith F. Aronson ◽

...

Keyword(s):

Guinea Pigs ◽

Viral Infections ◽

Lassa Virus ◽

Proof Of Concept ◽

Macrophage Response ◽

Pichinde Virus ◽

Viral Haemorrhagic Fever ◽

Transcription Factor Proteins ◽

Normal Macrophage

Viral haemorrhagic fever (VHF) is caused by a number of viruses, including arenaviruses. The pathogenesis is believed to involve dysregulation of cytokine production. The arenaviruses Lassa virus and Pichinde virus have a tropism for macrophages and other reticuloendothelial cells and both appear to suppress the normal macrophage response to virus infection. A decoy thioaptamer, XBY-S2, was developed and was found to bind to AP-1 transcription factor proteins. The P388D1 macrophage-like cell line contains members of the AP-1 family which may act as negative regulators of AP-1-controlled transcription. XBY-S2 was found to bind to Fra-2 and JunB, and enhance the induction of cytokines IL-6, IL-8 and TNF-α, while reducing the binding to AP-1 promoter elements. Administration of XBY-S2 to Pichinde virus-infected guinea pigs resulted in a significant reduction in Pichinde virus-induced mortality and enhanced the expression of cytokines from primary guinea pig macrophages, which may contribute to its ability to increase survival of Pichinde virus-infected guinea pigs. These data demonstrate a proof of concept that thioaptamers can be used to modulate the outcome of in vivo viral infections by arenaviruses by the manipulation of transcription factors involved in the regulation of the immune response.

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