Differential role for CD277 as a co-regulator of the immune signal in T and NK cells.

The human butyrophilin (BTN) 3 or CD277 molecules belong to the B7 family members and are expressed in various immune cells such as T and NK cells. Here, we show that CD277 triggering considerably enhances TCR-induced cytokine production and cell proliferation, even when another co-stimulatory molecule, CD28, is engaged. These CD277-induced additive functional effects are in accordance with the detection of early T-cell activation events such as TCR-induced cell signaling being increased upon CD277 engagement.

PD-L2 is expressed on activated human T cells and regulates their function.

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC.

B and T lymphocyte attenuator is highly expressed on CMV-specific T cells during infection and regulates their function.

B and T lymphocyte attenuator (BTLA), like its relative programmed cell death-1 (PD-1), is a receptor that negatively regulates murine T cell activation. However, its expression and function on human T cells is currently unknown. We report in this study on the expression of BTLA in human T cell subsets as well as its regulation on virus-specific T cells during primary human CMV infection.