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Development of a model for marburgvirus based on severe-combined immunodeficiency mice.

Warfield KL, Alves DA, Bradfute SB, Reed DK, VanTongeren S, Kalina WV, Olinger GG, Bavari S - Virol. J. (2007)

Bottom Line: Here, we demonstrate that serially passaging liver homogenates from MARV-infected severe combined immunodeficient (scid) mice was highly successful in reducing the time to death in scid mice from 50-70 days to 7-10 days after MARV-Ci67, -Musoke, or -Ravn challenge.We performed serial sampling studies to characterize the pathology of these scid mouse-adapted MARV strains.These scid mouse-adapted MARV models appear to have many similar properties as the MARV models previously developed in guinea pigs and nonhuman primates.

View Article: PubMed Central - HTML - PubMed

Affiliation: United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA. kelly.warfield@us.army.mil

ABSTRACT
The filoviruses, Ebola (EBOV) and Marburg (MARV), cause a lethal hemorrhagic fever. Human isolates of MARV are not lethal to immmunocompetent adult mice and, to date, there are no reports of a mouse-adapted MARV model. Previously, a uniformly lethal EBOV-Zaire mouse-adapted virus was developed by performing 9 sequential passages in progressively older mice (suckling to adult). Evaluation of this model identified many similarities between infection in mice and nonhuman primates, including viral tropism for antigen-presenting cells, high viral titers in the spleen and liver, and an equivalent mean time to death. Existence of the EBOV mouse model has increased our understanding of host responses to filovirus infections and likely has accelerated the development of countermeasures, as it is one of the only hemorrhagic fever viruses that has multiple candidate vaccines and therapeutics. Here, we demonstrate that serially passaging liver homogenates from MARV-infected severe combined immunodeficient (scid) mice was highly successful in reducing the time to death in scid mice from 50-70 days to 7-10 days after MARV-Ci67, -Musoke, or -Ravn challenge. We performed serial sampling studies to characterize the pathology of these scid mouse-adapted MARV strains. These scid mouse-adapted MARV models appear to have many similar properties as the MARV models previously developed in guinea pigs and nonhuman primates. Also, as shown here, the scid-adapted MARV mouse models can be used to evaluate the efficacy of candidate antiviral therapeutic molecules, such as phosphorodiamidate morpholino oligomers or antibodies.

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Histological changes in livers of mice infected with 'scid-adapted' MARV. Scid mice were challenged IP with 1000 pfu of 'scid-adapted' MARVCi67 and tissue samples were collected on days 0, 2, 4, 6, and 8 after challenge (n = 4–5/group). (A, C, and E) Tissues from the MARV-infected mice were stained with hematoxylin and eosin and representative pictures from day 0 (A), 4 (C), and 6 (E) are shown. The liver from the MARV-infected mouse contains multifocal necrosis, hepatocellular disruption, fatty cell degeneration, scattered hepatocellular viral inclusions, and inflammation composed of variable numbers of neutrophils and lesser numbers of macrophages and lymphocytes. (B, D, and F) Immunohistochemistry was performed on tissue sections from days 0 (B), 4 (D), and 6 (F) and MARV antigen appears brown. In the liver, MARV antigen is localized at the hepatocellular surface and most prominently noted along the sinusoids. Magnifications for A-B and D-F were 20× and panel C is shown at 40×.
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Figure 5: Histological changes in livers of mice infected with 'scid-adapted' MARV. Scid mice were challenged IP with 1000 pfu of 'scid-adapted' MARVCi67 and tissue samples were collected on days 0, 2, 4, 6, and 8 after challenge (n = 4–5/group). (A, C, and E) Tissues from the MARV-infected mice were stained with hematoxylin and eosin and representative pictures from day 0 (A), 4 (C), and 6 (E) are shown. The liver from the MARV-infected mouse contains multifocal necrosis, hepatocellular disruption, fatty cell degeneration, scattered hepatocellular viral inclusions, and inflammation composed of variable numbers of neutrophils and lesser numbers of macrophages and lymphocytes. (B, D, and F) Immunohistochemistry was performed on tissue sections from days 0 (B), 4 (D), and 6 (F) and MARV antigen appears brown. In the liver, MARV antigen is localized at the hepatocellular surface and most prominently noted along the sinusoids. Magnifications for A-B and D-F were 20× and panel C is shown at 40×.

Mentions: Compared to uninfected scid mice (Figure 5A–B), within the livers of mice infected with "scid-adapted" MARV, there was single-cell hepatocellular necrosis with neutrophilic infiltrates beginning at day 4 which progressed from multifocal to coalescing areas of moderate to severe hepatocellular degeneration and necrosis (Figures 5C and 5E) by days 6 and 8. Fatty cell degeneration of the remaining hepatocytes was also a consistent finding at days 6 and 8. TUNEL-positive apoptotic-like bodies were frequently co-located within areas of hepatocellular necrosis and foci of neutrophilic inflammation (data not shown). Immunohistochemically, within 4 days of infection, many hepatocytes and Kupffer cells expressed strong surface immunoreactivity for MARV antigen (Figure 5D) and within 6 days, almost all hepatocytes and Kupffer cells were positive for MARV antigen.


Development of a model for marburgvirus based on severe-combined immunodeficiency mice.

Warfield KL, Alves DA, Bradfute SB, Reed DK, VanTongeren S, Kalina WV, Olinger GG, Bavari S - Virol. J. (2007)

Histological changes in livers of mice infected with 'scid-adapted' MARV. Scid mice were challenged IP with 1000 pfu of 'scid-adapted' MARVCi67 and tissue samples were collected on days 0, 2, 4, 6, and 8 after challenge (n = 4–5/group). (A, C, and E) Tissues from the MARV-infected mice were stained with hematoxylin and eosin and representative pictures from day 0 (A), 4 (C), and 6 (E) are shown. The liver from the MARV-infected mouse contains multifocal necrosis, hepatocellular disruption, fatty cell degeneration, scattered hepatocellular viral inclusions, and inflammation composed of variable numbers of neutrophils and lesser numbers of macrophages and lymphocytes. (B, D, and F) Immunohistochemistry was performed on tissue sections from days 0 (B), 4 (D), and 6 (F) and MARV antigen appears brown. In the liver, MARV antigen is localized at the hepatocellular surface and most prominently noted along the sinusoids. Magnifications for A-B and D-F were 20× and panel C is shown at 40×.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2164958&req=5

Figure 5: Histological changes in livers of mice infected with 'scid-adapted' MARV. Scid mice were challenged IP with 1000 pfu of 'scid-adapted' MARVCi67 and tissue samples were collected on days 0, 2, 4, 6, and 8 after challenge (n = 4–5/group). (A, C, and E) Tissues from the MARV-infected mice were stained with hematoxylin and eosin and representative pictures from day 0 (A), 4 (C), and 6 (E) are shown. The liver from the MARV-infected mouse contains multifocal necrosis, hepatocellular disruption, fatty cell degeneration, scattered hepatocellular viral inclusions, and inflammation composed of variable numbers of neutrophils and lesser numbers of macrophages and lymphocytes. (B, D, and F) Immunohistochemistry was performed on tissue sections from days 0 (B), 4 (D), and 6 (F) and MARV antigen appears brown. In the liver, MARV antigen is localized at the hepatocellular surface and most prominently noted along the sinusoids. Magnifications for A-B and D-F were 20× and panel C is shown at 40×.
Mentions: Compared to uninfected scid mice (Figure 5A–B), within the livers of mice infected with "scid-adapted" MARV, there was single-cell hepatocellular necrosis with neutrophilic infiltrates beginning at day 4 which progressed from multifocal to coalescing areas of moderate to severe hepatocellular degeneration and necrosis (Figures 5C and 5E) by days 6 and 8. Fatty cell degeneration of the remaining hepatocytes was also a consistent finding at days 6 and 8. TUNEL-positive apoptotic-like bodies were frequently co-located within areas of hepatocellular necrosis and foci of neutrophilic inflammation (data not shown). Immunohistochemically, within 4 days of infection, many hepatocytes and Kupffer cells expressed strong surface immunoreactivity for MARV antigen (Figure 5D) and within 6 days, almost all hepatocytes and Kupffer cells were positive for MARV antigen.

Bottom Line: Here, we demonstrate that serially passaging liver homogenates from MARV-infected severe combined immunodeficient (scid) mice was highly successful in reducing the time to death in scid mice from 50-70 days to 7-10 days after MARV-Ci67, -Musoke, or -Ravn challenge.We performed serial sampling studies to characterize the pathology of these scid mouse-adapted MARV strains.These scid mouse-adapted MARV models appear to have many similar properties as the MARV models previously developed in guinea pigs and nonhuman primates.

View Article: PubMed Central - HTML - PubMed

Affiliation: United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA. kelly.warfield@us.army.mil

ABSTRACT
The filoviruses, Ebola (EBOV) and Marburg (MARV), cause a lethal hemorrhagic fever. Human isolates of MARV are not lethal to immmunocompetent adult mice and, to date, there are no reports of a mouse-adapted MARV model. Previously, a uniformly lethal EBOV-Zaire mouse-adapted virus was developed by performing 9 sequential passages in progressively older mice (suckling to adult). Evaluation of this model identified many similarities between infection in mice and nonhuman primates, including viral tropism for antigen-presenting cells, high viral titers in the spleen and liver, and an equivalent mean time to death. Existence of the EBOV mouse model has increased our understanding of host responses to filovirus infections and likely has accelerated the development of countermeasures, as it is one of the only hemorrhagic fever viruses that has multiple candidate vaccines and therapeutics. Here, we demonstrate that serially passaging liver homogenates from MARV-infected severe combined immunodeficient (scid) mice was highly successful in reducing the time to death in scid mice from 50-70 days to 7-10 days after MARV-Ci67, -Musoke, or -Ravn challenge. We performed serial sampling studies to characterize the pathology of these scid mouse-adapted MARV strains. These scid mouse-adapted MARV models appear to have many similar properties as the MARV models previously developed in guinea pigs and nonhuman primates. Also, as shown here, the scid-adapted MARV mouse models can be used to evaluate the efficacy of candidate antiviral therapeutic molecules, such as phosphorodiamidate morpholino oligomers or antibodies.

Show MeSH
Related in: MedlinePlus