There was no change in the peak day of shedding (Figure 2Ciii). Open in a separate window Figure 3. Virus shedding among ferrets infected with human respiratory syncytial virus (hRSV), followed at intervals of 3, 7, or 11 days by 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09). and .05 and ** .01. and and .05 and ** .01. Primary infection Eucalyptol with A(H1N1)pdm09 prevented subsequent infection with hRSV in 3 of 4 ferrets when primary infection and challenge were separated by 3 days. Shedding of hRSV was minimal in the single ferret infected, compared with control animals (Figure 1B and ?and1C).1C). No ferrets in this group seroconverted to hRSV (Figure 2Bi and 2Bii). Primary Rabbit Polyclonal to RPL30 infection with A(H1N1)pdm09 prevented infection with hRSV in 2 of 4 ferrets when infections were separated by 7 days (Figure 1D). Ferrets that did not shed virus did not seroconvert (Figure 2Bi and 2Bii), while ferrets that shed virus seroconverted to hRSV (Figure 2Bi and 2Bii). Prior infection with A(H1N1)pdm09 did not prevent infection with hRSV 11 days later (Figure 1E), with all ferrets showing a similar pattern of virus shedding (Figure 1B) and antibody titers to control animals Eucalyptol that Eucalyptol received hRSV alone (Figure 2Bi and 2Bii). The kinetics of hRSV shedding was examined in animals not protected from hRSV challenge. The peak of hRSV shedding was delayed in ferrets infected with A(H1N1)pdm09 followed by hRSV as compared to control animals infected with hRSV alone (median, 8 vs 6 days; = .0091 by the Mann-Whitney test; Figure 2Ci). There was no change in the duration of virus shedding (Figure 2Cii). Clinical signs following hRSV challenge were minimal (Supplementary Figure 2), consistent with our previous study [21]. All ferrets, except 1 control ferret infected with hRSV, maintained or gained weight (Supplementary Figure 2= .0196 by the Mann-Whitney test; Figure 2Civ). There was no change in the peak day of shedding (Figure 2Ciii). Open in a separate window Figure 3. Virus shedding among ferrets infected with human respiratory syncytial virus (hRSV), followed at intervals of 3, 7, or 11 days by 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09). A and D, Control ferrets infected with A(H1N1)pdm09 alone. B, C, and E, Ferrets underwent primary infection with 105 plaque-forming units (PFU) of hRSV strain Long following by challenge with 103.5 50% tissue culture infectious doses of A(H1N1)pdm09 3 (B), 7 (E), or 11 (C) days later. Note that control animals in panel A were in the same experiment as the test ferrets in the 3-day interval (B) and 11-day interval (C) groups, whereas control animals in panel D were in the same experiment as the test ferrets in the 7-day interval group (E). Quantitative reverse-transcription polymerase chain reaction analysis was used to detect the A(H1N1)pdm09 hemagglutinin gene (filled) and the hRSV N gene (striped) in viral RNA from nasal wash (NW) samples. The lower dotted lined indicate the limit of detection of infectious A(H1N1)pdm09, and the upper dotted lines indicate the limit of detection of infectious hRSV. Prior infection with hRSV did reduce disease following infection with A(H1N1)pdm09. The mean maximum weight loss (SD) among 8 control ferrets infected with A(H1N1)pdm09 was 10.6% 3.7% (Supplementary Figure 3and 3= .0002 by the Mann-Whitney test). No fever was detected following A(H1N1)pdm09 infection (Supplementary Figure 3= .2828 by the Mann-Whitney test; Supplementary Figure 5= .097; granzyme A, = .18; Figure 5E and ?and5F).5F). On day 6/7 after infection, levels of granzyme A, granzyme B, IFN-, interleukin 17, and MCP-1 mRNA were significantly higher in animals infected with A(H1N1)pdm09 as compared to those infected with hRSV (Figure 5FCH, ?,5M,5M, and ?and5N).5N). There was significant increase in expression of interleukin 8 (IL-8) mRNA 2 days after infection and of interleukin 1, IL-6, and IL-8 mRNAs 6/7 days after infection in ferrets infected with hRSV as compared to A(H1N1)pdm09 (Figure 5C, ?,5I,5I, and ?and5J).5J). This suggests a localized inflammatory response was induced after hRSV infection, which coincided with the increase in hRSV virus.
