Changes in HPBMC markers of immmune function following controlled short-term inhalation exposures of humans to hardwood smoke

<p>Previous studies have shown that complex mixtures containing particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) produce systemic immunotoxicity in animal models following inhalation exposures. While we and others have shown that emissions associated with hardwood smoke (HWS), cigarette smoke and diesel exhaust can suppress the immune systems of animals <i>in vitro</i> and <i>in vivo</i>, there have been few immune function studies on human peripheral blood mononuclear cells (HPBMC) following exposure of humans to HWS. Our work shows that T cells are an important targets of PM and PAH immunotoxicity. These studies were conducted on HPBMC from 14 human volunteers receiving four 2 h nightly exposures to clean air or HWS at a concentration of 500 ug/m³. We measured anti-CD3/anti-CD28 stimulated T-cell proliferation and HPBMC cytokine production in cell supernatants, including interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), TH1 cytokines γIFN and IL-2, TH2 cytokine IL-4, Th17 cytokine interleukin 17A (IL-17A) and interleukin 10 (IL-10). We analyzed results using analysis of variance (ANOVA), <i>t</i>-tests and Pearson correlation. Results showed that there was significant variation in the amount of T-cell proliferation observed following polyclonal activation with anti-CD3/anti-CD28 antibodies in both the air and HWS-exposed groups. There was not a significant effect of HWS on T-cell proliferation. However, we did find a strong relationship between the presence of proinflammatory cytokines (IL-1β, TNF-α, IL-6, but not IL-8) and the amount of T-cell proliferation seen in individual donors, demonstrating that brief exposures of humans to HWS can produce changes in systemic immunity that is associated with proinflammatory cytokines.</p

Inhalation delivery of topotecan is superior to intravenous exposure for suppressing lung cancer in a preclinical model

<p>Intravenous (IV) topotecan is approved for the treatment of various malignancies including lung cancer but its clinical use is greatly undermined by severe hematopoietic toxicity. We hypothesized that inhalation delivery of topotecan would increase local exposure and efficacy against lung cancer while reducing systemic exposure and toxicity. These hypotheses were tested in a preclinical setting using a novel inhalable formulation of topotecan against the standard IV dose. Respirable dry-powder of topotecan was manufactured through spray-drying technology and the pharmacokinetics of 0.14 and 0.79 mg/kg inhalation doses were compared with 0.7 mg/kg IV dose. The efficacy of four weekly treatments with 1 mg/kg inhaled vs. 2 mg/kg IV topotecan were compared to untreated control using an established orthotopic lung cancer model for a fast (H1975) and moderately growing (A549) human lung tumors in the nude rat. Inhalation delivery increased topotecan exposure of lung tissue by approximately 30-fold, lung and plasma half-life by 5- and 4-folds, respectively, and reduced the maximum plasma concentration by 2-fold than the comparable IV dose. Inhaled topotecan improved the survival of rats with the fast-growing lung tumors from 7 to 80% and reduced the tumor burden of the moderately-growing lung tumors over 5- and 10-folds, respectively, than the 2-times higher IV topotecan and untreated control (<i>p</i> < .00001). These results indicate that inhalation delivery increases topotecan exposure of lung tissue and improves its efficacy against lung cancer while also lowering the effective dose and maximum systemic concentration that is responsible for its dose-limiting toxicity.</p

rPA antibody-specific Toxin Neutralization Assay (TNA) and ED50 values (μg/mL).

<p>(A) generated from vaccinated wild type and (B) mutant rPA (geometric mean with error bars representing the 95% confidence interval).</p

Experimental Procedures and Schedule.

<p>^aThrice daily observations performed on Days 72–74. Twice daily observations performed other days.</p><p>^bBody weight obtained at randomization, on Day 0 and weekly thereafter.</p><p>^cAnimals vaccinated via intramuscular injection on Day 0 or Days 0 and 28 (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130952#pone.0130952.t001" target="_blank">Table 1</a>).</p><p>^dBlood collected and sera isolated for TNA and ELISA on Days -6, 14, 28, 42 and 65 ± 4, when moribund euthanized or at terminal euthanasia (Day 84).</p><p>^eRabbits challenged with 200 x ± 50 LD₅₀<i>B</i>. <i>anthracis</i> (Ames) spores. The published inhalation LD₅₀ for NZW rabbits is 1.1 x 10⁵ spores.</p><p>^fBlood collected for CBC and differential.</p><p>^gBlood collected and sera isolated for clinical chemistry parameters.</p><p>^hBlood collected for quantitative bacteriology.</p><p>ⁱBlood collected and sera isolated for electrochemiluminescence assay (ECL).</p><p>^jMoribund euthanized or found dead rabbits received a limited gross necropsy.</p><p>^kEuthanized or found dead rabbits received a gross necropsy and select tissues collected for bacteriology or histopathology.</p><p>Experimental Procedures and Schedule.</p

Recovery of <i>B</i>. <i>anthracis</i> from Select Tissues of vaccinated, unvaccinated control, and sham vaccinated control rabbits.

<p>Recovery of <i>B</i>. <i>anthracis</i> from Select Tissues of vaccinated, unvaccinated control, and sham vaccinated control rabbits.</p

Kaplan-Meier Survival Curve of vaccinated, unvaccinated control, and sham vaccinated control rabbits.

<p>Kaplan-Meier Survival Curve of vaccinated, unvaccinated control, and sham vaccinated control rabbits.</p

p Values Associated with Comparison of Ig anti-PA Values between Vaccine Groups as Analyzed by Repeated Measures ANOVA.

<p>Ig anti-PA levels from blood draws between day -1 and 65 were analyzed by repeated measures ANOVA.</p><p>The Ig anti-PA response of non-vaccinated groups (None and Vehicle, not shown above) were significantly lower (p < 0.0001) than every other group except each other.</p><p>^↓Indicates the Ig anti-PA response of the vaccine group listed on the left is significantly less than the corresponding vaccine group listed on the top of the table.</p><p>^↑Indicates the Ig anti-PA response of the vaccine group listed on the left is significantly greater than the corresponding vaccine group listed on the top of the table.</p><p>NS, no statistical significance between the two groups.</p><p>p Values Associated with Comparison of Ig anti-PA Values between Vaccine Groups as Analyzed by Repeated Measures ANOVA.</p

Study Summary of Fate and Immune Status Relevant to B. anthracis Challenge on Day 70.

<p>^aLower limit of quantitation < 30 μg/mL.</p><p>^bSamples which returned an incalculable ED50 (by Gen 5 software) were assigned an ED50 value of 1.</p><p>Study Summary of Fate and Immune Status Relevant to B. anthracis Challenge on Day 70.</p