The human immunodeficiency viruses (HIV) are two species of Lentivirus that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, the average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype.
Simian immunodeficiency virus (SIV) is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was isolated from the mainland by rising sea levels about 11,000 years ago, it has been concluded that SIV has been present in monkeys and apes for at least 32,000 years, and probably much longer.
C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines.
Following infection with HIV-1, the rate of clinical disease progression varies between individuals. Factors such as host susceptibility, genetics and immune function, health care and co-infections as well as viral genetic variability may affect the rate of progression to the point of needing to take medication in order not to develop AIDS.
C-X-C chemokine receptor type 4 (CXCR-4) also known as fusin or CD184 is a protein that in humans is encoded by the CXCR4 gene. The protein is a CXC chemokine receptor.
Chemokine ligand 5 is a protein which in humans is encoded by the CCL5 gene. The gene has been discovered in 1990 by in situ hybridisation and it is localised on 17q11.2-q12 chromosome. It is also known as RANTES. RANTES was first described by Dr. Tom Schall who named the protein, the original source of the name Rantes was from the Argentine movie Man Facing Southeast about an alien who shows up in a mental ward who was named Rantés, the rather clunky acronym was only made to fit the name.
HIV tropism refers to the cell type in which the human immunodeficiency virus (HIV) infects and replicates. HIV tropism of a patient's virus is measured by the Trofile assay.
Chemokine receptors are cytokine receptors found on the surface of certain cells that interact with a type of cytokine called a chemokine. There have been 20 distinct chemokine receptors discovered in humans. Each has a rhodopsin-like 7-transmembrane (7TM) structure and couples to G-protein for signal transduction within a cell, making them members of a large protein family of G protein-coupled receptors. Following interaction with their specific chemokine ligands, chemokine receptors trigger a flux in intracellular calcium (Ca2+) ions (calcium signaling). This causes cell responses, including the onset of a process known as chemotaxis that traffics the cell to a desired location within the organism. Chemokine receptors are divided into different families, CXC chemokine receptors, CC chemokine receptors, CX3C chemokine receptors and XC chemokine receptors that correspond to the 4 distinct subfamilies of chemokines they bind. The four subfamilies of chemokines differ in the spacing of structurally important cysteine residues near the N-terminal of the chemokine.
Chemokine ligand 7 (CCL7) is a small cytokine that was previously called monocyte-chemotactic protein 3 (MCP3). CCL7 is a small protein that belongs to the CC chemokine family and is most closely related to CCL2.
CXC chemokine receptors are integral membrane proteins that specifically bind and respond to cytokines of the CXC chemokine family. They represent one subfamily of chemokine receptors, a large family of G protein-linked receptors that are known as seven transmembrane (7-TM) proteins, since they span the cell membrane seven times. There are currently six known CXC chemokine receptors in mammals, named CXCR1 through CXCR6.
Chemokine ligand 16 (CXCL16) is a small cytokine belonging to the CXC chemokine family. Larger than other chemokines, CXCL16 is composed of a CXC chemokine domain, a mucin-like stalk, a transmembrane domain and a cytoplasmic tail containing a potential tyrosine phosphorylation site that may bind SH2. These are unusual features for a chemokine, and allow CXCL16 to be expressed as a cell surface bound molecule, as well as a soluble chemokine. CXCL16 is produced by dendritic cells found in the T cell zones of lymphoid organs, and by cells found in the red pulp of the spleen. Cells that bind and migrate in response to CXCL16 include several subsets of T cells, and natural killer T (NKT) cells. CXCL16 interacts with the chemokine receptor CXCR6, also known as Bonzo. Expression of CXCL16 is induced by the inflammatory cytokines IFN-gamma and TNF-alpha. The gene for human CXCL16 is located on chromosome 17.
CD4 immunoadhesin is a recombinant fusion protein consisting of a combination of CD4 and the fragment crystallizable region, similarly known as immunoglobulin. It belongs to the antibody (Ig) gene family. CD4 is a surface receptor for human immunodeficiency virus (HIV). The CD4 immunoadhesin molecular fusion allow the protein to possess key functions from each independent subunit. The CD4 specific properties include the gp120-binding and HIV-blocking capabilities. Properties specific to immunoglobulin are the long plasma half-life and Fc receptor binding. The properties of the protein means that it has potential to be used in AIDS therapy as of 2017. Specifically, CD4 immunoadhesin plays a role in antibody-dependent cell-mediated cytotoxicity (ADCC) towards HIV-infected cells. While natural anti-gp120 antibodies exhibit a response towards uninfected CD4-expressing cells that have a soluble gp120 bound to the CD4 on the cell surface, CD4 immunoadhesin, however, will not exhibit a response. One of the most relevant of these possibilities is its ability to cross the placenta.
C-C chemokine receptor type 7 is a protein that in humans is encoded by the CCR7 gene. Two ligands have been identified for this receptor: the chemokines ligand 19 (CCL19/ELC) and ligand 21 (CCL21). The ligands have similar affinity for the receptor, though CCL19 has been shown to induce internalisation of CCR7 and desensitisation of the cell to CCL19/CCL21 signals. CCR7 is a transmembrane protein with 7 transmembrane domains, which is coupled with heterotrimeric G proteins, which transduce the signal downstream through various signalling cascades. The main function of the receptor is to guide immune cells to immune organs by detecting specific chemokines, which these tissues secrete.
C-C chemokine receptor type 1 is a protein that in humans is encoded by the CCR1 gene.
Chemokine like receptor 1 also known as ChemR23 is a protein that in humans is encoded by the CMKLR1 gene. Chemokine receptor-like 1 is a G protein-coupled receptor for the chemoattractant adipokine chemerin and the omega-3 fatty acid eicosapentaenoic acid-derived specialized pro-resolving molecule, resolvin E1. The murine receptor that shares almost 80% homology with the human receptor, is called Dez.
C-C chemokine receptor type 3 is a protein that in humans is encoded by the CCR3 gene.
Chemokine receptor 8, also known as CCR8, is a protein which in humans is encoded by the CCR8 gene. CCR8 has also recently been designated CDw198.
G protein-coupled receptor 15 is a protein that in humans is encoded by the GPR15 gene.
Atypical chemokine receptor 3 also known as C-X-C chemokine receptor type 7 (CXCR-7) and G-protein coupled receptor 159 (GPR159) is a protein that in humans is encoded by the ACKR3 gene.
Vpx is a virion-associated protein encoded by human immunodeficiency virus type 2 HIV-2 and most simian immunodeficiency virus (SIV) strains, but that is absent from HIV-1. It is similar in structure to the protein Vpr that is carried by SIV and HIV-2 as well as HIV-1. Vpx is one of five accessory proteins carried by lentiviruses that enhances viral replication by inhibiting host antiviral factors.
