Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2013 Jan 21;5(1):295-320.
doi: 10.3390/v5010295.

Innate and adaptive immune response to pneumonia virus of mice in a resistant and a susceptible mouse strain

Affiliations
Comparative Study

Innate and adaptive immune response to pneumonia virus of mice in a resistant and a susceptible mouse strain

Ellen R T Watkiss et al. Viruses. .

Abstract

Respiratory syncytial virus (RSV) is the leading cause of infant bronchiolitis. The closely related pneumonia virus of mice (PVM) causes a similar immune-mediated disease in mice, which allows an analysis of host factors that lead to severe illness. This project was designed to compare the immune responses to lethal and sublethal doses of PVM strain 15 in Balb/c and C57Bl/6 mice. Balb/c mice responded to PVM infection with an earlier and stronger innate response that failed to control viral replication. Production of inflammatory cyto- and chemokines, as well as infiltration of neutrophils and IFN-γ secreting natural killer cells into the lungs, was more predominant in Balb/c mice. In contrast, C57Bl/6 mice were capable of suppressing both viral replication and innate inflammatory responses. After a sublethal infection, PVM-induced IFN-γ production by splenocytes was stronger early during infection and weaker at late time points in C57Bl/6 mice when compared to Balb/c mice. Furthermore, although the IgG levels were similar and the mucosal IgA titres lower, the virus neutralizing antibody titres were higher in C57Bl/6 mice than in Balb/c mice. Overall, the difference in susceptibility of these two strains appeared to be related not to an inherent T helper bias, but to the capacity of the C57Bl/6 mice to control both viral replication and the immune response elicited by PVM.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Weight loss and accumulation of virus in the lungs following infection with PVM 15 in Balb/c and C57Bl/6 mice. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu, 300 pfu, or 3000 pfu of PVM 15 and weighed daily for 7 days following infection, and 4 mice per group were sacrificed daily. (A-B) median weight for each group, expressed as a percentage of the starting weight, with error bars indicating the interquartile range. (C-D) median viral load for each group with error bars indicating the interquartile range. a: p <0.05 compared to control group; b. p <0.05 between 3000 and 300 pfu; c: p <0.05 between 3000 and 30 pfu; d: p <0.05 between 300 and 30 pfu. Differences in virus replication with the control groups are not shown.
Figure 2
Figure 2
Histopathological analysis of PVM-infected mice. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu, 300 pfu, or 3000 pfu of PVM 15 and lungs were collected from four mice on day 6 p.i. for histopathological analysis. In (A), representative lung sections for animals scoring 0, 1, 2, and 3 are shown, with the upward arrows (↑) indicating infiltrating inflammatory cells and the downward arrows (↓) indicating oedema in the tissue. The bronchiole is labeled with the letter B and the blood vessel with V. Scores were given on the basis of the severity and dissemination of the lesions visible in duplicate lung sections, and median values are shown for each group (B).
Figure 3
Figure 3
Cytokine expression by Balb/c and C57Bl/6 mice following infection with PVM 15. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu, 300 pfu, or 3000 pfu of PVM 15 and lungs were collected from four mice per group on days 3 (A and C) and 5 p.i. (B and D). Expression levels of IFN-α (A and B) and IFN-γ (C and D) transcripts were calculated using the Bio-Rad analysis software (Bio-Rad CFX Manager Version 2.0), normalized against the expression of both β-actin and GAPDH housekeeping genes, and expressed as the normalized fold-change over mock-infected control animals euthanized on the same day p.i.. Each data point represents a single animal and the line represents the group median. *, p <0.05.
Figure 4
Figure 4
Chemokine expression by Balb/c and C57Bl/6 mice following infection with PVM 15. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu, 300 pfu, or 3000 pfu of PVM 15 and lungs were collected from four mice per group on days 3 (AD) and 5 p.i. (EH). The expression levels of CXCL8 (A and E), CXCL10 (B and F), CCL3 (C and G), and CCL2 (D and H) were calculated using the Bio-Rad analysis software (Bio-Rad CFX Manager Version 2.0), normalized against the expression of both β-actin and GAPDH housekeeping genes, and expressed as the normalized fold-change over mock-infected control animals euthanized on the same day p.i.. Each data point represents a single animal and the line represents the group median. *, p <0.05.
Figure 5
Figure 5
Infiltration of immune cells in Balb/c and C57Bl/6 mice in response to PVM infection. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu, or 300 pfu of PVM 15 and sacrificed on days 3 and 5 p.i.. Cells collected from the pooled lung washes of 4–6 animals were stained and analyzed for the presence of macrophages, neutrophils, lymphocytes , and eosinophils. The average number of these cells is shown, calculated based on the number of total cells collected from the group and the proportion of these cell populations in the lungs.
Figure 6
Figure 6
Percentage of IFN-γ secreting NK cells in lungs of Balb/c and C57Bl/6 mice in response to PVM infection. Five to six week old-mice were inoculated with medium (control), or 30 pfu (Balb/c), or 300 pfu (C57Bl/6) of PVM 15 and sacrificed on day 6 p.i.. Cells collected from pooled lungs of five animals were stained with anti-CD8a-FITC, anti-CD3-PE, anti-CD4-FITC, anti-CD335(NKp46)PerCP-CyTM 5.5 for surface markers, followed by permeabilization and fixation with BD Cytofix/CytopermTM Plus and staining with anti-IFN-γ-APC. Flow cytometry was performed using a FACS Calibur (BD Biosciences), and data analysis was performed using Kaluza software. Median values with interquartile range are shown. **, p <0.01; ***, p <0.001.
Figure 7
Figure 7
PVM-specific antibody response in the serum and lungs. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu (Balb/c) or 300 pfu (C57Bl/6) of PVM 15 and sacrificed on days 14, 28, and 42 p.i.. Time course of (A) lung IgA, (B) lung IgG, and (C) serum IgG, represented as the group median with vertical lines indicating the interquartile range. VN titres on day 28 in lung (D) and serum (E). Each data point represents a single animal and the line represents the group median. *, p <0.05; **, p <0.01.
Figure 8
Figure 8
PVM-specific IFN-γ-secreting (A) and IL-5-secreting (B) splenocytes following in vitro restimulation with PVM-infected cell lysates. Five to six week-old Balb/c and C57Bl/6 mice were inoculated with medium, 30 pfu (Balb/c) or 300 pfu (C57Bl/6) and sacrificed on days 14, 28, and 42 p.i.. The PVM-specific response is calculated by subtracting the number of cytokine-secreting cells restimulated with mock-infected cell lysates from those restimulated with PVM-infected lysates. The data points represent individual animals, with the median indicated by a line. **, p <0.01.

Similar articles

Cited by

References

    1. Bonville C.A., Bennett N.J., Koehnlein M., Haines D.M., Ellis J.A., DelVecchio A.M, Rosenberg H.F., Domachowske J.B. Respiratory dysfunction and proinflammatory chemokines in the pneumonia virus of mice (PVM) model of viral bronchiolitis. Virology. 2006;349:87–95. doi: 10.1016/j.virol.2006.02.017. - DOI - PubMed
    1. Rosenberg H.F., Bonville C.A., Easton A.J., Domachowske J.B. The pneumonia virus of mice infection model for severe respiratory syncytial virus infection: Identifying novel targets for therapeutic intervention. Pharmacol. Ther. 2005;105:1–6. doi: 10.1016/j.pharmthera.2004.09.001. - DOI - PubMed
    1. El-Hajje M.J., Lambe C., Moulin F., Suremain N., Pons-Catalano C., Chalumeau M., Raymond J., Lebon P., Gendrel D. The burden of respiratory viral disease in hospitalized children in Paris. Eu. Eur. J. Pediatr. 2008;167:435–436. doi: 10.1007/s00431-007-0529-5. - DOI - PubMed
    1. Deshpande S.A., Northern V. The clinical and health economic burden of respiratory syncytial virus disease among children under 2 years of age in a defined geographical area. Arch. Dis. Child. 2003;88:1065–1069. doi: 10.1136/adc.88.12.1065. - DOI - PMC - PubMed
    1. Iwane M.K., Edwards K.M., Szilagyi P.G., Walker F.J., Griffin M.R., Weinberg G.A., Coulen C., Poehling K.A., Shone L.P., Balter S., et al. Population-based surveillance for hospitalizations associated with respiratory syncytial virus, influenza virus, and parainfluenza viruses among young children. Pediatrics. 2004;113:1758–1764. doi: 10.1542/peds.113.6.1758. - DOI - PubMed

Publication types

MeSH terms

LinkOut - more resources