Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Subscribe

Logo for

Science 340 (6129): 207-211

Copyright © 2013 by the American Association for the Advancement of Science

Persistent LCMV Infection Is Controlled by Blockade of Type I Interferon Signaling

John R. Teijaro1,*, Cherie Ng1,*, Andrew M. Lee1,{dagger}, Brian M. Sullivan1, Kathleen C. F. Sheehan2, Megan Welch1, Robert D. Schreiber2, Juan Carlos de la Torre1, and Michael B. A. Oldstone1,{ddagger}

1 Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
2 Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA.


Figure 1
View larger version (17K):
[in this window]
[in a new window]

 
Fig. 1. IFN-I is elevated early after onset of persistent virus infection. Serum levels of IFN-β (A) and IFN-α species (B) as measured by enzyme-linked immunosorbent assay (ELISA) after initiation of persistent Cl13 or acute Arm infections in mice at 18, 24, 48, 120, and 240 hpi in C57BL/6J mice. (C) pDCs are preferentially infected early after Cl13 infection. Percent of GFP-positive pDCs infected with {Delta}GP-Cl13 or {Delta}GP-ARM viruses 24 hpi. *P < 0.05; ***P < 0.005. Results are representative of two to three independent experiments and represent the SEM from three to five mice per group.

 

Figure 2
View larger version (55K):
[in this window]
[in a new window]

 
Fig. 2. IFN-I signaling is essential for the expression of the negative immune regulators IL-10 and PD-L1 and lymphoid tissue disorganization after persistent virus infection. Mice were treated with anti-IFNAR1 1 day before infection. (A) Serum levels of IL-10 as measured by ELISA on days 1, 5, and 9 after cl13 infection in C57BL/6J mice treated with either isotype control antibodies or anti-IFNAR1. (B) Mean fluorescent intensity (MFI) of PD-L1 expression as determined by flow cytometry on either LCMV viral antigen positive (VL-4+) or viral antigen negative (VL-4) splenic DCs 1 day after cl13 infection. (C) Representative histograms of PD-L1 expression as determined by flow cytometry on either infected or uninfected (shaded histograms) CD8α-negative DCs (left) or compiled PD-L1 expression (right) at day 5 after Cl13 infection. (D) Histogram of PD-L1 expression (left) and mean fluorescent intensity (right) as determined by flow cytometry on splenic CD8α-negative dendritic cells at day 9 after Cl13 infection. Histopathological and immunofluorescent analysis of spleens on days 9 (E) and 14 (F) after Cl13 infection from naïve mice or mice infected with Cl13 and treated with isotype antibodies or anti-IFNAR1 as above. (Top) Hematoxylin and eosin (H&E) histopathological analysis. (Middle) Staining for a stromal cell marker (ER-TR7, a marker for fibroblastic reticular cells) and T cells (CD3). (Bottom) B cell staining (B220). Images were taken with a 5x objective. Scale bars indicate 500 μm. **P < 0.01; ***P < 0.005. Results are representative of two independent experiments and represent the SEM from five mice per group.

 

Figure 3
View larger version (15K):
[in this window]
[in a new window]

 
Fig. 3. IFN-I signaling blockade controls persistent virus infection. C57BL/6J mice were treated with either isotype control antibody or anti-IFNAR1 1 day before infection with Cl13 (A and B) or 10 days after Cl13 infection (C and D). (A) Serum viral titers determined by plaque assay at the indicated times postinfection. (B) Viral titers in serum or indicated tissues at day 40 after infection. (C and D) Mice were infected with Cl13 and, 10 dpi, treated with three doses of anti-IFNAR1 (500 μg on days 10 and 12 and 250 μg on day 14). The graphs illustrate serum titers of mice 50 dpi in the serum (C) and lung and liver (D). **P < 0.01; ***P < 0.005; #P = 0.07. Results are representative of more than five independent experiments and represent the SEM from five mice per group. PFU, plaque-forming units.

 

Figure 4
View larger version (48K):
[in this window]
[in a new window]

 
Fig. 4. Control of persistent virus by IFN-I blockade correlates with altered T cell trafficking and requires CD4 T cells. C57BL/6J mice were treated with isotype control antibody or anti-IFNAR1 before infection with CL13. (A) At 5 and 14 dpi, mice received adoptive transfers of CFSE-labeled naïve T cells. Two hours after transfer, spleens were harvested to analyze homing and localization of naïve T cells (green) to T cell zones [CD3, red; fibroblastic reticular cells (ER-TR7), blue]. Images were taken with a 20x objective. Scale bars, 100 μm. (B) Quantitation of naïve T cell localization. The number of transferred CFSE-labeled naïve T cells was counted in 10 random white pulp regions per spleen. (C) Total number of cytokine-producing GP33-41 LCMV-specific CD8 T cells in the spleen on day 9 postinfection. (D) Total number of cytokine-producing GP61-80 LCMV-specific CD4 T cells in the spleen on day 9 postinfection. (E to G) Mice treated with anti-CD4 and/or anti-IFNAR1 or control antibodies were infected with 2 x 106 PFU of Cl13, and viral titers were measured in the serum and tissues at the indicated times postinfection. Viral titers in the serum were quantified by plaque assay on days 14, 21, and 40 (E) and 50 (F) in the serum. (G) Viral titers in the lung, kidney, and brain in CD4-depleted mice treated with isotype or anti-IFNAR1 on day 75 postinfection. n.s., not significant; *P < 0.05; **P < 0.01; ***P < 0.005. Results are representative of two independent experiments and represent SEM from four or five mice per group.

 


To Advertise     Find Products


Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882