Alloreactive conventional T cell (Tconv) (Tconv)

Alloreactive conventional T cells (Tconv) are a subset of T lymphocytes that recognize non-self major histocompatibility complex (MHC) molecules, serving as the primary mediators of immune-driven transplant complications (Nature Reviews Immunology, 2018). In the context of hematopoietic stem cell transplantation, donor-derived alloreactive Tconv recognize recipient antigens, leading to graft-versus-host disease (GvHD), where they infiltrate and damage organs such as the skin, liver, and gastrointestinal tract (StatPearls, 2023). Conversely, in solid organ transplantation, recipient alloreactive Tconv recognize donor MHC, resulting in graft rejection (Journal of Clinical Investigation, 2017). These cells are characterized by the expression of T-cell receptors (TCR) and coreceptors like CD4 or CD8, and their activation requires costimulatory signals (Frontiers in Immunology, 2020). Pharmacological intervention typically involves the use of calcineurin inhibitors, such as tacrolimus, or T-cell depleting agents like antithymocyte globulin to mitigate their destructive activity (Blood, 2021). A major therapeutic challenge is selectively targeting alloreactive Tconv while preserving regulatory T cells and the beneficial graft-versus-leukemia (GvL) effect (Science Translational Medicine, 2019). Monitoring these cells often involves assessing activation markers like CD25 or HLA-DR and cytokine production such as interferon-gamma (Clinical & Experimental Immunology, 2015).

Other names

Alloreactive T lymphocyteDonor-derived conventional T cellAlloreactive T-cellEffector T cell

Inhibition of calcineurin signaling, blockade of mTOR-mediated proliferation, depletion via antibody-dependent cellular cytotoxicity, and inhibition of costimulatory signals.