Semaphorin-4A is a cell surface protein with known functions in neural development and immune regulation, but the mechanism for immune modulation is unclear. Here the authors show that ILT-4, previously found on myeloid cells, is the receptor of Semaphorin-4A on activate human CD4 T cells for mediating T cell co-stimulation.
- Ning Lu
- Ying Li
- Lieping Chen