Innate Immunity - Anatomy

CD19, CD20, and CD21 are all normal B-cell surface proteins and can thus be used as markers for B-cell lymphomas.

All of these options, except ICAM-1, are soluble mediators that drive different elements of immune response. These soluble mediators are more like cytokines than is ICAM-1, which is a structural adhesin that facilitates polymorphonuclear cells sticking to the side of blood vessels. This neutrophil margination is the first step toward diapedesis, or the crossing of the cells into the peripheral tissue to carry out their function.

TNF-alpha is routinely involved in inflammation and helps regulate the response of the cells of the innate immune system. Overexpression of TNF-alpha can lead to overstimulation of these immune cells, resulting in the autoimmune disorder of rheumatoid arthritis.

Chemokines are a type of cytokine (signaling molecule) that recruits other cells to the sight of an infection. Interferons have antiviral properties and activate the inflammatory response, interleukins are responsible for growth and differentiation of leukocytes, and tumor necrosis factor is responsible for mediating many immune functions and facilitates the destruction of tumor cells.

When complement is activated, blood vessels dilate, not constrict. Direct consequences of complement activation include: membrane attack complex forms, dilates blood vessels, attracts neutrophils and macrophages, inflammation, mast cells stimulated, bacteria is made more readily engulfed or opsonized, and antibody-antigen complexes are solubilized.

B-lymphocytes are part of the adaptive immunity system, they create plasma cells and antibodies when they recognize a specific antigen. Monocytes are what macrophages are before they leave the bloodstream. Basophils contain granules of histamine which produce an inflammation response when released. Natural killer cells attack infected or cancerous cells.

The white blood cells are typically categorized into several major types. Each of these types have specific roles in the body, and their proportions will change during specific body conditions. Basophils are used to dilate blood vessels by releasing histamine and eosinophils become elevated during parasitic infections and allergy season. Neutrophils play an important role in recruiting other immune cells to damaged tissues. Lymphocytes include B-cells and T-cells and are involved in the adaptive immune response. Monocytes are the preliminary cells that differentiate into macrophages, which are involved in non-specific phagocytosis.

White blood cells can be classified by whether or not they have granules in their cytoplasm (granulocytes and agranulocytes). There are three types of granulocytes, and all of them end in the suffix "-phil." Neutrophils, basophils, and eosinophils are considered granulocytes. Lymphocytes are agranulocytes, and do not have granules present in their cytoplasm.

Basophils are part of the innate immunity, and are a key player for stimulating inflammation. Basophils release histamine, which dilates blood vessels and increases the permeability of capillaries. This allows an infection to be walled off in the affected area and helps other white blood cells migrate to the area.

Eosinphils are involved in parasitic immunity and allergic reactions. Neutrophils, macrophages, and monocytes are responsible for phagocytosing foreign pathogens. B-lymphocytes release antibodies against a specific antigen.

NADPH oxidase is the first enzyme that can be expected to generate radicals from molecular oxygen. Once the radicals have been generated, they react with another enzyme to generate hydrogen peroxide, a more stable molecule. This generation of a stable intermediate protects the polymorphonuclear cell itself from damage.

The final step mediated by myeloperoxidase generates hypochlorite, or bleach, that ultimately kills the ingested pathogens.

Mast cells contain granules which are released to cause inflammation and attract other cells to the area. B-cells that form plasma cells and antibodies when a specific antigen is recognized. Dendritic cells are those that process proteins in lymph fluid, they have long "arms." Macrophages are the cells that engulf and consume cell debris or infectious organisms.

The innate immune system includes structures that prevent infection, as well as those that take on a non-specific, but active role. A macrophage would be a good example of a non-specific, active innate immune cell. The remainder of the options, with the exception of a neuron, are also preventive structures. Epithelial cells form a barrier to the outside, potentially contaminated environment. Microglia are monocyte-derived, macrophage-like cells in the central nervous system. Astrocytes form the blood-brain barrier, preventing potentially infectious material in the blood from getting to the central nervous system. As neurons lie behind this barrier, they would play the least important role in any kind of innate immunity.

Superoxide dismutase is in the same radical pathway that involves NADPH oxidase. As a result, it is most likely to be found in nonspecific cells of the innate immune system, such as polymorphonuclear cells.

C3b is involved in coating bacteria to tag them for degradation by phagosomes, and is activated by the complement system. The alternative complement pathway is activated during innate immunity and activates C3b.

All B-cells are involved in adaptive immunity, including memory B-cells and plasma cells (which as derived from B-cells). C1qrs is involved in the classical complement pathway, but requires antibody-antigen interaction from the adapative immune system.

Plasma cells are the only answer option that is not involved with phagocytosis. Plasma cells are derived from B-cells and serve as the primary source of antibody production during the adaptive immune response.

C3b coats bacteria so that macrophages target them for ingestion. Neutrophils are also capable of causing cell lysis and phagocytosis.

The innate immune system is the non-specific immune system that you are born with. Cells of the innate immune system include mast cells, macrophages, neutrophils (and other white cells), natural killer cells, and complement (a group of proteins found in the blood). The B cells are associated with the adaptive immune system, producing antibodies, and providing a memory component of the immune system. The innate immune system does not have a memory component.

A mast cell is similar to a basophil in that their granules, which contain histamine and heparin, produce inflammation when released. Also, mast cells play a role in angiogenesis during wound healing. A T-cell is a cell that targets infected cells to destroy. Plasma cells are antibody-producing cells. B-cells form plasma and antibodies in response to specific antigens.

B-cells are stimulated by antigens, which in turn leads to antibody production. Antibodies then are used to neutralize invaders or tag them for destruction. T-cells are divided into helper T-cells, killer T-cells, regulatory T-cells types. Natural killer cells destroy cells that have become infected with pathogens and additionally also cancer cells. Basophils are a type of granulocyte that are active in allergic and inflammatory responses.

The white blood cells are typically categorized into several major types. Each of these types have specific roles in the body, and their proportions will change during specific body conditions. Basophils are used to dilate blood vessels by releasing histamine and eosinophils become elevated during parasitic infections and allergy season. Neutrophils play an important role in recruiting other immune cells to damaged tissues. Lymphocytes include B-cells and T-cells and are involved in the adaptive immune response. Monocytes are the preliminary cells that differentiate into macrophages, which are involved in non-specific phagocytosis.