Streptococcus pneumoniae (S. pneumoniae) are Gram positive bacteria that normally colonize the nasopharynx of most healthy individuals, but can lead to invasive infections including pneumonia, a disease responsible for 1.6 million deaths annually worldwide. Neutrophils are one of the first responders during S. pneumoniae lung infection and are required for control of infection. We previously found that extracellular adenosine (EAD) production by CD73 regulates host resistance and neutrophilic responses during infection. EAD is produced by exonucleosidases and signals via four G-protein coupled receptors, A1R, A2AR, A2BR and A3R that are expressed on neutrophils. However, the contribution of specific receptor(s) to host resistance against S. pneumoniae is unknown. For my thesis I am investigating the role of A2BR, a low affinity adenosine receptor in neutrophil responses and host resistance during infection.