C-type lectin domain family 2 member D (CLEC2D)

C-type lectin domain family 2 member D (CLEC2D) is a type II transmembrane C-type lectin-like receptor mainly expressed on activated antigen-presenting cells such as B cells, dendritic cells, and subsets of T lymphocytes[2][3][1]. CLEC2D encodes the LLT1 (lectin-like transcript 1) protein, the only functional ligand for CD161 (NKR-P1A) on human NK and T cells[2][1]. Engagement of LLT1 with CD161 modulates immune responses by inhibiting NK cell cytotoxicity and cytokine production, and can costimulate T cell activation under certain conditions, leading to increased inflammatory cytokine release[2]. Increased LLT1 expression on tumor cells has been implicated in immune evasion during cancer, particularly by suppressing NK cell function[2][3]. CLEC2D also inhibits osteoclast formation, contributing to bone homeostasis, and may function as a pattern recognition receptor recognizing histone sequences released from necrotic cells, thus initiating sterile inflammatory responses[1][2]. CLEC2D/LLT1 is under study as a potential therapeutic target in cancer, autoimmunity, and inflammatory diseases due to its regulatory role in both innate and adaptive immunity[2][4][3][1].

Other names

LLT1OCILCLAXLectin-like NK cell receptorLectin-like transcript 1Osteoclast inhibitory lectinC-type lectin related f

Inhibition or modulation of NK-cell mediated lysis via engagement of LLT1 (CLEC2D) on target cells with CD161 (NKR-P1A) on NK and T cells Modulation of cytokine release via receptor-ligand engagement