Costimulationsmarker

Costimulationsmarker is a nonstandard term used in immunology to denote a molecular indicator involved in co-stimulatory signaling during immune cell activation. The term is more commonly described in English as a co-stimulatory marker or co-stimulatory molecule, and in some Nordic-language sources it may appear as costimuleringsmarkør. In the canonical model of T cell activation, a first signal is delivered when the T cell receptor recognizes an antigen-MHC complex. A second signal, delivered by co-stimulatory receptors and ligands, is required for optimal activation, proliferation, and survival.

Key co-stimulatory pathways include CD28–B7 (CD80/CD86), ICOS–ICOSL, CD40–CD40L, 4-1BB (CD137), and OX40 (CD134). Inhibitory counterpoints such as CTLA-4 and PD-1 regulate or dampen co-stimulatory signaling, shaping the balance between activation and tolerance. The landscape of co-stimulation is thus a network rather than a single interaction, with context-dependent outcomes in different cell types and microenvironments.

Researchers refer to these molecules as costimulatory markers because their presence or engagement indicates active co-stimulation and helps predict T cell responses. Detection methods include flow cytometry for surface proteins, transcript analysis to assess expression, and functional readouts such as IL-2 production, T cell proliferation, or NF-κB activation.

Applications of understanding costimulatory markers span vaccine development, cancer immunotherapy (including checkpoint inhibitors and co-stimulatory agonists), and transplantation tolerance. Terminology is context-dependent; while costimulationsmarker can appear in some sources, the standard terms are co-stimulatory molecule or co-stimulatory pathway.