Naive T cellIn immunology, a naive T cell (Th0 cell) is a T cell that has differentiated in the thymus, and successfully undergone the positive and negative processes of central selection in the thymus. Among these are the naive forms of helper T cells (CD4+) and cytotoxic T cells (CD8+). Any naive T cell is considered immature and, unlike activated or memory T cells, has not encountered its cognate antigen within the periphery. After this encounter, the naive T cell is considered a mature T cell.
Laboratory mouseThe laboratory mouse or lab mouse is a small mammal of the order Rodentia which is bred and used for scientific research or feeders for certain pets. Laboratory mice are usually of the species Mus musculus. They are the most commonly used mammalian research model and are used for research in genetics, physiology, psychology, medicine and other scientific disciplines. Mice belong to the Euarchontoglires clade, which includes humans.
Cell signalingIn biology, cell signaling (cell signalling in British English) or cell communication is the ability of a cell to receive, process, and transmit signals with its environment and with itself. Cell signaling is a fundamental property of all cellular life in prokaryotes and eukaryotes. Signals that originate from outside a cell (or extracellular signals) can be physical agents like mechanical pressure, voltage, temperature, light, or chemical signals (e.g., small molecules, peptides, or gas).
Wnt signaling pathwayThe Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling pathways use either nearby cell-cell communication (paracrine) or same-cell communication (autocrine). They are highly evolutionarily conserved in animals, which means they are similar across animal species from fruit flies to humans.
LckLck (or lymphocyte-specific protein tyrosine kinase) is a 56 kDa protein that is found inside specialized cells of the immune system called lymphocytes. The Lck is a member of Src kinase family (SFK), it is important for the activation of the T-cell receptor signaling in both naive T cells and effector T cells. The role of the Lck is less prominent in the activation or in the maintenance of memory CD8 T cells in comparison to CD4 T cells. In addition, the role of the lck varies among the memory T cells subsets.
Clonal deletionIn immunology, clonal deletion is the removal through apoptosis of B cells and T cells that have expressed receptors for self before developing into fully immunocompetent lymphocytes. This prevents recognition and destruction of self host cells, making it a type of negative selection or central tolerance. Central tolerance prevents B and T lymphocytes from reacting to self. Thus, clonal deletion can help protect individuals against autoimmunity. Clonal deletion is thought to be the most common type of negative selection.
Notch signaling pathwayThe Notch signaling pathway is a highly conserved cell signaling system present in most animals. Mammals possess four different notch receptors, referred to as NOTCH1, NOTCH2, NOTCH3, and NOTCH4. The notch receptor is a single-pass transmembrane receptor protein. It is a hetero-oligomer composed of a large extracellular portion, which associates in a calcium-dependent, non-covalent interaction with a smaller piece of the notch protein composed of a short extracellular region, a single transmembrane-pass, and a small intracellular region.
Molecular switchA molecular switch is a molecule that can be reversibly shifted between two or more stable states. The molecules may be shifted between the states in response to environmental stimuli, such as changes in pH, light, temperature, an electric current, microenvironment, or in the presence of ions and other ligands. In some cases, a combination of stimuli is required. The oldest forms of synthetic molecular switches are pH indicators, which display distinct colors as a function of pH.
Cell growthCell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater than the overall rate of cellular degradation (the destruction of biomolecules via the proteasome, lysosome or autophagy, or catabolism). Cell growth is not to be confused with cell division or the cell cycle, which are distinct processes that can occur alongside cell growth during the process of cell proliferation, where a cell, known as the mother cell, grows and divides to produce two daughter cells.
Molecular machineMolecular machines are a class of molecules typically described as an assembly of a discrete number of molecular components intended to produce mechanical movements in response to specific stimuli, mimicking macromolecular devices such as switches and motors. Naturally occurring or biological molecular machines are responsible for vital living processes such as DNA replication and ATP synthesis. Kinesins and ribosomes are examples of molecular machines, and they often take the form of multi-protein complexes.
