Multi-functional lectin-like transcript-1: A new player in human immune regulation

• LLT1 and CD161 are lectin–like receptors encoded within the NKC.
• LLT1 regulates NK cells, the germinal centre reaction and bone metabolism.
• CD161 is associated with NK cells and innate-like functions across T cell subsets.
• The expression of CD161 in tumours is associated with positive outcomes.

Lectins and C-type lectins are a heterogeneous group of proteins with a diverse range of functions. Two C-type lectins, found in the Natural Killer gene Complex (NKC), Lectin-like transcript 1 (LLT1) and CD161, have recently gained interest from a broad range of immunological and non-immunological fields. LLT1 in particular has a diverse functional repertoire, from NK cell and B cell regulation to bone metabolism. This review seeks to bring together nearly two decades of research on these receptors and describe their importance in the immune system.