This invention describes an advance in understanding the regulation of the immune response. Triggering Receptors in Myeloid Cells (TREM) recently were discovered to modulate innate and adaptive immunity. Specifically, TREM1 amplifies the response to sepsis in innate immunity by activating neutrophils and other leukocytes; and TREM2 potentiates dendritic cell maturation in adaptive immunity. This invention describes a new inhibitory TREM like Transcript, TLT-1.

TLT-1 is the first inhibitory receptor discovered to reside within the TREM gene locus. This discovery implies the receptor has an important regulatory role in both innate and adaptive immunity. Structurally, TLT-1 also possesses inhibitory domains that indicate this regulatory function. TLT-1 is highly expressed in peripheral blood platelets and may modulate many other types of myeloid cells. Potential therapeutic implications are for immune disorders, cancer, septic shock, infectious disease, stroke, heart disease, myocardial infarction, vascular disorders, and other platelet-associated disorders.