Molecules, Vol. 25, Pages 3102: Granzyme B PET Imaging of the Innate Immune Response

Molecules, Vol. 25, Pages 3102: Granzyme B PET Imaging of the Innate Immune Response Molecules doi: 10.3390/molecules25133102 Authors: Kathleen M. Capaccione Mikhail Doubrovin Nikunj Bhatt Akiva Mintz Andrei Molotkov The human immune system is a complex system which protects against invaders and maintains tissue homeostasis. It is broadly divided into the innate and adaptive branches. Granzyme B is serine protease that plays an important role in both and can serve as a biomarker for cellular activation. Because of this, a granzyme B PET agent (GZP) has recently been developed and has been shown to be able to monitor response to immunotherapy. Here, we evaluated the utility of granzyme B PET imaging to assess the innate immune response. We subcutaneously administered LPS to mice to induce inflammation and performed granzyme B PET imaging after 24 and 120 h. We dissected out tissue in the region of injection and performed granzyme B immunofluorescence (IF) to confirm specificity of the GZP radiotracer. Granzyme B PET imaging demonstrated increased uptake in the region of LPS injection after 24 h, which normalized at 120 h. Granzyme B immunofluorescence showed specific staining in tissue from the 24 h time point compared to the PBS-injected control. These findings support the use of granzyme B PET for imaging innate immunity. In certain clinical contexts, the use of GZP PET imaging may be superior to currently available agents, and we therefore suggest further pr...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research