Germ-Fighting Inhaler Could Fend Off Bioterror Agents

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But Steven Mizel, a professor of microbiology and immunology at Wake Forest University Health Sciences in Winston-Salem, NC, was skeptical.

"If first responders get a cut on their finger, they are still dead," he said.

That's because the protection afforded by ALIIS is limited to inhaled pathogens; challenge with injected bacteria still resulted in death, Scott noted. But Scott believes this finding is also a benefit, as it suggests the drug induces only a localized immune response, rather than a potentially damaging, whole-body one.

Scott also noted that ALIIS neither induced mucus formation not exacerbated asthma, and that repeated exposure of mice to the treatment appeared to cause little long-term damage beyond fibrosis, a thickening of the airways.

ALIIS induces massive stimulation of the so-called innate immune response, a hodge-podge of antimicrobial peptides (proteins), growth factors, and white blood cells that collectively, though non-specifically, deal with potential pathogens. Indeed, it does this so well, Scott said, that microbes died virtually on contact with the lining of the airway.

But ALIIS has no effect on the other arm of immunity, the adaptive response of B and T lymphocytes that are responsible for protective antibodies and long-term immunological memory. As a result, Mizel said, its potential real-world efficacy could be limited.

"I think this research supports the contention that the innate immune response is being triggered, and that is a good holding action," Mizel said. But he added that, "you need adaptive immunity to kick in eventually," especially if the body is exposed to large doses of pathogen, as is likely during a bioterror incident.

"If you are at the epicenter of the attack, and there are high concentrations of bacteria around, I would be shocked if the innate immune system could handle that," he said.

Study senior author Dr. Burton Dickey and Scott have formed a company called Pulmotect to commercialize ALIIS. Clinical trials are in the planning stages, Scott said, but will have to wait at least until safety and efficacy studies in other animal models can be completed.

More information

For more information on infectious disease, visit the U.S. Centers for Disease Control and Prevention.