TNF impairs macrophage killing of Streptococcus pneumoniae

As people age, the levels of tumour necrosis factor (TNF) in their blood tend to increase. TNF is a major chemical messenger responsible for causing inflammation. Older adults with high levels of TNF in their blood are more likely to catch pneumonia. People with high blood TNF levels are also more likely to be admitted to the ICU or die after being hospitalised for pneumonia. TNF worsens the ability of immune cells called macrophages to destroy the bacteria that cause pneumonia. This purpose will explore how inflammation and TNF impair macrophage function. It will examine whether TNF can be targeted to improve older adults’ responses to infections and to understand whether higher levels of TNF in males explains their increased susceptibility to and death from pneumonia compared to females.