However, the physiological functions of DCIR are not fully understood. DCIR has been associated with some autoimmune Regorafenib diseases. DCIR was detected at the surface of plasmacytoid DCs and may regulate DC expansion. In myeloid or plasmacytoid DCs, internalization of DCIR inhibits the response of TLR8 or TLR9, two Toll-like receptors known to play an important role in innate immunity against viruses. DCIR is the product of the human gene CLEC-4A, which encodes a protein 237 amino acid residues in length and is unique among the lectin receptors due to the presence of several unique structural motifs. It contains an intracellular signalling consensus sequence known as immunoreceptor tyrosine-based inhibition motif or ITIM, a neck domain important for HIV-1 binding that includes a carbohydrate recognition domain extracellular portion, and an EPS motif, that is, a specific galactose recognition domain. We have determined that the ITIM motif is required for Niltubacin DCIR-mediated enhancement of HIV- 1 infection. Furthermore, we have shown, using antibodies directed against the EPS motif or CRD domain, or by deleting the neck domain, that these extracellular portions are both involved in the binding of HIV-1 and its subsequent transfer to CD4TL. Given this potentiation of HIV infection through interaction with DCIR, our objective was to develop a molecule to inhibit HIV binding to DCIR. Considering that the virus-encoded viral envelope glycoprotein gp120 is one of the most heavily glycosylated proteins known in nature and that DC-SIGN-dependent HIV-1 capture requires interaction between gp120 and the CRD domain of DCSIGN, it might be that a similar interaction allows DCIR to act as an attachment factor for HIV-1. The EPS motif of DCIR is known to bind specifically to galactosyl residues of glycoproteins. Since galactosyl residues are present on the surface of HIV-1, we designed and synthesized chemical inhibitors targeting the EPS and/or CRD domains of DCIR. Virtual screening has recently helped to discover ligands and inhibitors based on crystallographic and homology models of target proteins. Studies have shown that virtual docking to homology models frequently yields enrichment of known ligands as good as that obtained by docking to a crystal structure of the actual target protein. This structure-based approach to inhibitor design has been used to identify several inhibitors of 17bhydroxysteroid dehydrogenases and RNA-dependent RNA polymerase. Methodical analysis of the structure of DCIR is required to design potent and specific inhibitors of its interaction with HIV-1, via the CRD and/or EPS motifs, thereby generating potential new drugs. Since no complete or partial tertiary structure has been published for DCIR, we built a homology model using the structure of the CRD of CLEC4M, which also interacts with gp120, as a template. Based on this model, several inhibitors were selected using virtual screening and tested using various methods.