Three papers published online this week in Nature Immunology show that a previously uncharacterized protein called Themis is essential for proper development of T cells. These immune cells are critical for the recognition and elimination of pathogens.
Using distinctly different experimental approaches, teams led by Nicholas Gascoigne, Paul Love and Ronald Schwartz and Richard Cornall demonstrated that Themis is expressed exclusively in T cells. Each group independently generated and studied Themis-deficient animals, which they found contained few mature and functional T cells.
Adding to the mystery surrounding this unfamiliar protein, the three teams offer somewhat different explanations for how exactly Themis ― which bears little structural resemblance to any other proteins involved in T cell development ― facilitates T cell maturation. Future work is needed to clarify the mechanisms through which Themis influences development of this important immune cell lineage.