The Lung and the Immune System

Lung infections bullet 5: Streptococcus pneumoniae

“…It has been found, for example, that alveolar macrophages from patients with community acquired pneumonia are hyporesponsive to stimulation, with less release of pro-inflammatory cytokines than either circulating monocytes from the same patients or from alveolar macrophages from healthy control subjects 94. This is in keeping with the general tendency of alveolar macrophages to reduce or dampen down the immune response within the alveoli 95. It has also been observed that viable S pneumoniae in suspension inhibit the release of reactive oxygen species from PMNs, in contrast to Staphylococcus aureus and Klebsiella pneumoniae which each stimulate PMNs to release increased amounts of extracellular reactive oxygen species 46…”