Men get sick because they don’t have the hormones that boost women’s immune system, according to new research
Scientists from Harvard University have shown that a lack of oestrogen makes men more likely to succumb to pneumonia and other respiratory diseases.
Yet a simple dose of oestrogen was enough to cure both males and females of the serious lung infection.
Professor Lester Kobzik at the Harvard University School of Public Health found females are naturally more resistant to respiratory infections than males.
The study showed that increased resistance to bacterial pneumonia in female mice is linked to the enzyme nitric oxide synthase 3 (NOS3), which is ultimately activated by the release of the female sex hormone estrogen
Female mice and male mice that had been treated with oestrogen were able to clear the bacteria from their lungs more rapidly than normal male mice.
The scientists then took another set of male and female mice and removed the gene responsible for the production of NOS3, an enzyme activated by oestrogen.
They found that deleting this gene meant that the female mice were no longer more resistant to infection.
The team hopes that, in the future, this knowledge could be used to enhance resistance to common and serious lung infections and prevent flu developing into more serious pneumonia.
Professor Kobzik said: “Ultimately, this work could be especially useful in reducing risk of secondary bacterial pneumonias during seasonal or pandemic influenza.
“We were quite pleased that the work led us to NOS3-targeting drugs that are already available and that can indeed improve resistance to pneumonia in our mouse model.”