Immunology

BAFF belongs to the tumor necrosis factor (TNF) family, and its downstream signaling plays a critical role in B-cell survival and maturation. BAFF overproduction is associated with a variety of autoimmune diseases. BAFF is the functional ligand for three receptors:

VEGF is homodimeric, disulfide-linked glycoprotein cytokine that serves as the ligand for FLT1 (VEGFR-1 receptor) and FLK1 (VEGFR-2 receptor) tyrosine kinases. It is a key modulator of physiological angiogenesis, vasculogenesis, and endothelial cell growth during basic developmental processes such as embryogenesis, skeletal growth, and reproductive functions.

Toll-like receptor 4 (TLR4) belongs to the family of Toll-like receptors (TLR), and plays a main role in pathogen recognition and innate immunity system activation. The TLR family members are highly conserved proteins that all contain a high degree of structural and functional homology in organisms from Drosophila all the way up to humans. TLRs regulate the cellular cytokine production required for efficient innate immunity development through their recognition of pathogen-associated molecular patterns (PAMPs) expressed across a wide range of ligands, including infectious agents.

TLR2 is a member of the broad family of Toll-like receptors (TLR) that play an important role in pathogen recognition and innate immunity.

Beta-catenin is a cytosolic, 88 kDa intracellular protein associated with cell surface cadherin glycoproteins. It is a member of the larger calcium-dependent catenin family that includes alpha-catenin, beta-catenin, and gamma-catenin (also known as plakoglobin). Beta-catenin enters the nucleus to interact with TCF/LEF (Lymphoid enhancer factor-1) transcription factor family. It is normally inhibited by the GSK (glycogen synthase kinase) or CK1 (casein kinase 1) as phosphorylation of beta-catenin targets it for ubiquitin-mediated degradation.

CAS9 is a novel DNA-cutting enzyme that is the main component of an intrinsic DNA editing system used by bacteria to kill attacking viruses. Clustered regularly interspaced short palindromic repeats (CRISPR) are distinct features of most bacterial genomes, and thought to be involved in resistance to bacteriophages. CRISPR is a primitive immune system of sorts that determines resistance specificity, as published by the Danisco Corporation in Science¹.

The LAG3 protein belongs to the Ig superfamily and contains 4 extracellular Ig-like domains (D1-D4). This molecule plays an key role in the immune response through negative regulation of T-cell proliferation, function, and homeostasis. It is required for maximum natural and induced regulatory T-cell function. LAG3 is closely related to the T-cell co-receptor CD4, and like CD4, binds to MHC class II molecules - but with a significantly higher affinity. It is expressed exclusively in activated T- and natural killer (NK) lymphocytes.

TNF alpha is a multifunctional proinflammatory cytokine that belongs to the tumor necrosis factor (TNF)-receptor superfamily. It is involved in the regulation of a wide spectrum of biological processes: cell proliferation, differentiation, apoptosis, inflammation, lipid metabolism, and coagulation. TNF alpha has been implicated in a variety of autoimmune diseases (rheumatoid arthritis, Crohn's disease, multiple sclerosis, and psoriasis), insulin resistance, septic shock, and tumor metastases related to cancer.

The products of MHC genes are antigen-presenting molecules (APMs) designed for antigen fragment (peptide) presentation to the T-cell receptor. In particular, MHC Class I molecules play a key role in the immune system by presenting endogenously synthesized peptides derived from the endoplasmic reticulum (ER) lumen to CD8+ T-lymphocytes, which are usually cytotoxic T-cells. MHC Class I antigens are heterodimers consisting of one 44kD highly polymorphic alpha chain non-covalently complexed with an invariant 11.5kD beta2-microglobulin subunit.

Viruses infect host cells with their genetic material and then reproduce. They are found in humans, plants, bacteria and other places where they can infect cells, adapt and change. In celebration of Virus Appreciation Day, a day discover more about viruses, learn more about viruses in our infographic.