Adaptive immune system

Adaptive immune system - Vaccine's, such as the polio...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Vaccine's, such as the polio vaccine, take advantage of our bodies' adaptive immune system. Adaptive Immune System The cells of the immune system are not located in any one place or bound together to form a tissue as in most other systems in our body, nor is the immune system controlled by any central organ, such as the brain. Rather, the immune system is composed of a host of individual cells, an army of defenders that rush to the site of infection to combat invading microbes. These cells communicate and coordinate their actions through the release of chemical signals called cytokines (essentially a type of hormone) or sometimes through direct contact with each other via specific receptors. The cells of the immune system are derived from white blood cells. White blood cells , along with red blood cells, are formed from the cells in the bone marrow called hematopoietic stem cells . White blood cells are produced in the bone marrow and circulate in the blood. They are also found in lymph nodes, spleen, liver, thymus and bone marrow. Of the 100 trillion cells in the adult human, 2% are white blood cells. White blood cells include the phagocytes (macrophages and neutrophils) and lymphocytes (natural killer cells and T and B cells) (see figure 1). Macrophages, neutrophils and natural killer cells are all part of the innate immune system (discussed in the previous e-module), while the B and T cells function in the adaptive immune system . Adaptive Immune System Figure 1 Blood Cell Lineage Figure 3 B-cell Receptor Figure 2 Antigens Binding A major difference between the innate and adaptive immune system is the ability to recognize specific pathogens. In other words, while the innate immune system may recognize bacteria in general, the adaptive immune system will recognize a specific bacterium, such as Bordetella pertussis that causes whooping cough. By remembering a specific microbe, the adaptive immune system can respond more quickly and strongly to subsequent encounters with that microbe. This is why you may develop an infection with the first encounter of the microbe, such as the virus that causes chickenpox, but you won't get sick a second time. B and T cells are the immune cells that comprise the adaptive immune system. These cells can remember the microbes they encounter by recognizing very specific cell surface markers on those microbes. Every cell, including microbes, has molecules protruding from its surface. These molecules can be proteins, sugars or lipids. Antigens are these molecules that stick out from the surface of the microbe that stimulate B and T cells by binding to receptors located on B and T cells. Receptors are proteins that are usually located on the surface of a cell that can bind specific molecules. When a receptor is bound, specific information is communicated to the cell that dictates some sort of action by the cell. Each B or T cell expresses only one kind of receptor and therefore can bind only one type of antigen (see figure 2).type of antigen (see figure 2)....
View Full Document

Page1 / 12

Adaptive immune system - Vaccine's, such as the polio...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online