Adaptive immune cells, like T cells, play a critical role in protecting our bodies against invading pathogens, a task that relies upon their ability to recognize pathogens as foreign, or ‘non-self’. This begs the question, though, of how adaptive immune cells distinguish between self and non-self. How is it that T cells know to attack … Continue reading Positive and Negative Selection of T Cells
Much of current immunology research in is founded on enormous data sets, complex interactions, and computer modeling - tackling the microbiome or the origins of autoimmune disease, for example. Fundamental discoveries can seem few and far between amidst Big Data (data sets of size and complexity that computers are required for analysis, ‘-omics (proteomics, genomics, … Continue reading Location Location Location – T cell receptor placement makes or breaks immune response speed!
T cell receptors are required for the activation, regulation, and function of T cells. TCRs are generated by the random joining of gene segments in the TCR gene loci. TCR assembly occurs through a process called V(D)J recombination, so named for the gene segments joined to make the β–chain of the TCR and the heavy … Continue reading How-to make: a T cell receptor (the simpler version)
The history of medicine and epidemiology is full of “bad bug” stories---bacteria have a reputation for causing many horrible diseases like cholera and tuberculosis. More recently, however, research efforts like the Human Microbiome Project have turned to investigating the role that “ good bacteria” plays in everyday health. The human microbiome is complex, and consists … Continue reading When friend becomes foe: gut bacteria triggers autoimmunity in mice and humans
The microbiome is a group of microorganisms living in a particular environment (for example, the human gut). These microorganisms are not just limited to bacteria: viruses, fungi, and archaea can also be present. Microbiomes are not limited to humans or even to mammals--insects and plants have microbiomes that are crucial for their health. Microbiomes are … Continue reading The Mighty, Mighty Microbiome
Central Tolerance Central tolerance refers to the negative selection step in T cell differentiation. It occurs in the thymus, where newly recombined T cell receptors are screened against a bevy of self-antigens and overactive clones are deleted. See Positive and Negative Selection of T Cells. Clonal Deletion - T cells that recombine a TCR with a … Continue reading Regulating “self” versus “non-self” – T cell tolerance mechanisms
Autoimmunity is a blanket term describing pathologies where the immune system attacks its host body. The typical paradigm is that the immune system protects us from foreign invaders- pathogens looking for a niche to colonize. In autoimmune disease, the immune system mistakes our body’s tissues for a target- and harms them. Whether due to a … Continue reading Friendly Fire – an introduction to autoimmune disease
Phagocytosis is the process of a cell ingesting another cell or particle. It works by having the phagocytosing cell bind the desired target onto its surface and bringing it inward while it engulfs the target. This is a relatively simple mechanism that cells such as macrophages of the immune system can use to destroy foreign … Continue reading Neutralizing your enemies by eating them? Just an ordinary day in the life of the immune system!
In 1909, a German scientist named Paul Ehrlich made a simple yet shocking proposal: that cancer arises in our bodies quite frequently, but that it is usually eliminated by cells of the immune system before tumors form. Although radical at the time, Ehrlich’s theory gained experimental support in the mid-to-late 20th century, and it is … Continue reading MHC class I: a novel mediator of the “don’t eat me” signal
The major histocompatibility complex (MHC) genes code for proteins which the immune system uses to identify cells and tissues in the body as “self” or “other”. MHC molecules ‘talk’ to T cells which patrol the body for foreign invaders or dangerously mutated cells. The MHC acts as a window into our cells. It presents snippets … Continue reading What is MHC and why does it matter?