TIM-3

T cell immunoglobulin and mucin-containing molecule 3 (Tim-3), which was originally identified as a marker specific to interferon (IFN-γ) producing CD4+ T-cells, is emerging as one of the crucial immune checkpoint molecules in the pathogenesis of chronic diseases such as asthma, tuberculosis, rheumatoid arthritis, hepatitis C and tumors. 

TIM-3 in T cells

The first study of Tim-3 indicated it is important for autoimmune disease by regulating macrophage activation in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Notably, Tim-3 is considered a key obstacle to superable chronic viral infections and anti-tumour immunity in T cell dysfunction and exhaustion. 

TIM-3 in non-T cells

Experimental and clinical studies have found that Tim-3 is not only expressed on T cells but non-T cells including macrophages (MФ), dendritic cells (DCs), natural killer (NK) cells, and monocytes. Accumulating data indicate that Tim-3 has diverse roles of immune functions depending on the cell types and under various pathological conditions.