Immunology

IRAK4, also known as Interleukin-1 receptor-associated kinase 4, is a serine/threonine-protein kinase that plays a critical role in initiating innate and adaptive immune responses against foreign pathogens. It activates NF-kappaB in both Toll-like receptor (TLR) and T-cell receptor (TCR) signaling pathways.

Target of the antiproliferative 1 (TAPA1), also known as CD81, is found in the plasma membrane in lymphocytes and plays an important role in the regulation of lymphoma cell growth. This transmembrane 4 superfamily (TM4SF) protein is primarily found on CD4⁺CD8⁺ thymocytes as well as broadly in the periphery, with high-level expressed in cell cohorts such as B-cells, NK cells, macrophages, and dendritic cells.

Macrophage mannose receptor 1 (MRC1), also known as CD206, is a Pattern Recognition Receptor (PRR). PRRs are expressed by antigen processing and presentation cells, and are activated upon detection of Pathogen-Associated Molecular Patterns (PAMPs). PAMPs are molecular sequences shared by large groups of pathogens, which are essential for microbial survival and/or pathogenicity and include cell wall components such as glycoproteins.

The nuclear factor kappa B (NFkB) is a ubiquitous transcription factor essential for the activation of immune and inflammatory responses. NFkB activity is inhibited when it is associated with IkB proteins in the cell cytoplasm. IkB proteins are phosphorylated by the IkB kinase complex. The IKK serine protein kinase consists of alpha and beta subunits (IKK alpha and IKK beta). These subunits interact with each other and together, are essential for NFkB activation. IKK alpha is expressed in variety of human tissues.

The Toll-like receptor 9 (TLR9) protein, also known as CD289, belongs to the family of Toll-like receptor (TLR) proteins which play a large role in pathogen recognition and the activation of innate immunity. Scientists using TLR9 antibodies have found that TLRs are highly conserved from Drosophila to humans, with a high degree of structural and functional homology^1,2.

Transient receptor potential A1 (TRPA1) is an ion channel found on the plasma membrane of many cell types that functions in diverse sensory processes such as pain and temperature. The TRPA1 ion channel is specifically expressed in nociceptive neurons, as well as neurons who express the related protein TRPV1. In fact, Brierly et al used a TRPA1 antibody to discover that this ion channel is largely present on smaller neurons vs larger ones (1).

Platelet endothelial cell adhesion molecule 1 (PECAM1), also known as cluster of differentiation 31 (CD31), is a cell-surface glycoprotein expressed on platelets, monocytes, neutrophils, some types of T-cells and NK (natural killer) cells. It makes up a large portion of the endothelial cell intercellular junctions. CD31/PECAM1 is a member of the immunoglobulin superfamily and plays many different roles involving leukocyte migration under most inflammatory conditions, angiogenesis, integrin activation, atherosclerosis and thrombopoiesis.

TLR1 belongs to the Toll-like receptor (TLR) family, and is a key player in the recognition of pathogens as well as the activation of the innate immunity system. TLRs are highly conserved proteins with a high degree of structural and functional homology from Drosophila to humans. By recognizing pathogen-associated molecular patterns (PAMPs) that are exhibited across a spectrum of ligands, including infectious agents, TLRs modulate cellular cytokine production needed for efficient innate immunity development.

The protein TLR6 is one member of the large Toll-like receptor (TLR) family, which governs the activation of the innate immunity system and pathogen recognition in cells. The TLR family is highly conserved from Drosophila to humans, and all the family members have a high degree of both functional and structural homology. TLRs modulate cytokine production by cells that is required to effectively establish innate immunity.

CD4, also known as Cluster of Differentiation 4, interacts with major histocompatibility complex class II antigens, acts as a receptor for the human immunodeficiency virus and induces the aggregation of lipid rafts. It is expressed in T lymphocytes, B cells, macrophages, granulocytes, dendritic cells and specific regions of the brain.