Does the HIF-1α hypoxia response in tumor-infiltrating T lymphocytes induce functional CD137 ( 4-1BB ) for immunotherapy?
CD137 (4-1BB) is an important molecular target to augment antitumor immunity. Hypoxia in the tumor microenvironment as sensed by the HIF-1α system increases expression of CD137 on tumor-infiltrating lymphocytes that thereby become selectively responsive to the immunotherapeutic effects of anti-CD137 agonist monoclonal antibodies as those used in ongoing clinical trials.
Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans.