Activated alloantigen-reactive T cells expressing CD25 and CD71 (CD25+/CD71+ activated T cells)

Activated alloantigen-reactive T cells expressing CD25 and CD71 are the primary cellular mediators of acute Graft-versus-Host Disease (aGvHD) and solid organ transplant rejection (Groth et al., 2019, PubMed). CD25, the alpha chain of the interleukin-2 receptor, and CD71, the transferrin receptor, are markers that are significantly upregulated on the surface of T cells upon activation and entry into the cell cycle in response to foreign antigens (Xenikos, 2024). Targeting this specific cell population allows for the selective depletion of pathogenic, alloreactive T-cell clones while preserving the resting T-cell repertoire necessary for maintaining immunity against infections and tumors. This therapeutic strategy is exemplified by T-Guard, a combination of anti-CD25 and anti-CD71 monoclonal antibodies conjugated to ricin A-chain toxins, which induces targeted cell death in these activated lymphocytes (NCT04183946, ClinicalTrials.gov). By rapidly reducing the burden of activated alloreactive T cells, such therapies aim to suppress the hyper-inflammatory response in patients with steroid-refractory aGvHD.

Other names

Alloreactive T cellsActivated T lymphocytesCD25+ CD71+ T cellsPathogenic alloreactive T cells

Targeted depletion of activated T cells via immunotoxin-mediated inhibition of protein synthesis and induction of apoptosis