Prof. Dr. Dirk Baumjohann
Medical Clinic III for Oncology, Hematology, Immuno-Oncology and Rheumatology
dirk.baumjohann@uni-bonn.de View member: Prof. Dr. Dirk Baumjohann
Clinical science (London, England : 1979)
Bystander activation represents an innate-like mechanism by which T cells, particularly effector and memory subsets, can become activated in the absence of cognate antigen recognition. Using human tonsil organoid cultures as a physiologically relevant model, we investigated bystander activation of CD4+ memory T cells in situ in comparison to superantigen stimulation. Tonsillar T cells were stimulated with pertussis toxin - a component of the childhood pertussis vaccine - in comparison to TSST-1 as the staphylococcal superantigen and assessed for activation status, cytokine expression, RNA expression, and metabolic reprogramming. We observed robust T cell activation and cytokine production as well as transcriptional changes comparable to that elicited by TSST-1. Notably, both bystander- and superantigen-activated T memory cells exhibited a metabolic shift toward glycolysis as the dominant energy pathway. These findings demonstrate the similarities of bystander and superantigen-induced T cell activation and show up pathways to sway bystander activation depending on the immunological context.
Copyright 2026 The Author(s).
PMID: 42417073
Medical Clinic III for Oncology, Hematology, Immuno-Oncology and Rheumatology
dirk.baumjohann@uni-bonn.de View member: Prof. Dr. Dirk Baumjohann