Figure 1.
Aerosolized NTHi lysate protects against hemorrhagic influenza virus pneumonia.
(A) Gross pathologic images of lungs 7 days after influenza A challenge. (B) Mice were challenged with aerosolized influenza A (2.8×104 TCID50/ml) after receiving no NTHi lysate treatment, or NTHi lysate treatment 3 days before, 1 day before, or 1 day after infection (* p = 0.0001, † p = 0.011, ‡ p = 0.043 when each treated group was compared to the untreated group). (C) Weight changes in the same groups of mice shown in A. (D) Viral titers in lung homogenates were measured 4 days after viral challenge, with or without a single NTHi lysate pretreatment 1 day prior to infection (* p = 0.004).
Figure 2.
Protection against influenza A is associated with lung-restricted inflammation.
(A) Lung inflammatory cytokine levels were determined in mice treated with NTHi lysate once (“×1”), every third day for 6 days (“×3”), or not at all. ELISA was performed on BAL fluid obtained 4 h after the final treatment. (B) Lung inflammatory cytokines were measured 3 days after influenza A infection without NTHi lysate pretreatment, following a single treatment on day −1 before infection, or following treatments on days −7, −4, and −1 prior to infection. (C) Serum levels of inflammatory cytokines at designated timepoints after NTHi lysate treatment. (D) Inflammatory cell counts in BAL fluid of mice treated (or not) with NTHi lysate, as in A. (E) Inflammatory cell counts in BAL fluid of mice treated (or not) with NTHi lysate then infected with influenza A, as in B. (*p<0.01 compared with untreated).
Table 1.
Interferon gene expression changes following NTHi lysate treatment.
Figure 3.
Repeated doses of aerosolized NTHi lysate provide prolonged protection against influenza virus without tachyphylaxis.
(A) Mice were challenged with aerosolized influenza A without NTHi lysate pretreatment, following a single treatment on day −1 before infection, or following treatments on days −7, −4, and −1 prior to infection. Survival curves are shown (*p<0.0001). (B) Weight changes in the same groups of mice shown in A.
Figure 4.
Aerosolized NTHi lysate combined with ribavirin effectively treats influenza virus pneumonia.
After aerosolized challenge with ∼107 TCID50/mouse influenza A, mice were treated with high dose ribavirin (Rib), NTHi lysate, or a combination of the two. Combination treated mice received ribavirin+NTHi therapy for the days indicated, up to three days. (A) Survival at day 14 for each of the conditions (*p<0.0001, †p = 0.0002, ‡p0.2 compared with untreated). (B) Survival curves for each of the conditions in A.