Specific immunity, T cells

There are two types of T cells which involved in the specific immunity. One type is cytotoxic T cell or killer T cell. In this case when pathogen enter the cell, and that cell moves the protein to its surface, a patrolling T cell recognizes and binds to this protein and release profferrin, a protein which raptures a membrane of the infected cell. T cell can destroy a cancer cell.The second type of T cell is helper T cell. The role of helper T cell is to activate B cell. The B cell that responses has the same antigen that activates the helper T cells. The T cell sends out chemical signals that effect various immune cells. These chemicals stimulate B cells to divide and produce a clone of antibody releasing cells.
http://www.youtube.com/watch?v=tqjhMHG7J08&feature=related

Disruption of apoptosis in tumorogenesis

Apoptosis also known as cell suicide or “ programmed cell death” is a mechanism of the multicellular organisms that maintain the homeostasis of the lymphocytes (immune cells) and eliminates damaged or anneeded cells. We have learned in our Bio440 class that human body makes 100 million lymphocytes each day and that this process is absolutely necessary for the control of the number of immune cells. In this critical feature of clonal delution and self tolerance surviving lymphocyte will only respond to foreign antigens and not to autoantigens.

However, this short video clip shows that apoptosis is involved in development of many cancers. The key mediator of disruption of that mechanism and mutations of the cells is the P53 tumor suppressor gene that causes excessive cell growth and tumorogenesis. These cell mutations disrupt the natural suicide response and can cause cancer cells to develop resistance to both radiotherapy and chemotherapy.

http://www.researchapoptosis.com/apoptosis/multimedia/videos/video2/index.m

The Human Immune System: Vaccination

I really liked this animation, becuase it is very simple and very easy to understand what is going on. It shows antigents as dead pathogens that are injected into the human body. Then the lymphocytes detect the antigen and multiply, and then produce antibodies and memory cells. Then the antobodies gradually disappear but the memory cells stay for many years. When alive pathogens of the same type infects the body, the memory cells immediately make antibodies and destroy the pathogens.

http://resources.schoolscience.co.uk/ABPI/immune/immAnim3.htm

Cloning an Army of T Cells for Immune Defense

In unit 4 we studied immune system. The sells of our immune system discover and destroy foregn invaders, like bacteria or virus, that enter our bodies and may threaten our health. We learned that immune system cells defend out bodies by acting as a coordinated team. Specific molecules on their surfaces mediate the communication among immune system cells. In this animation we can see how one type of immune cell-the helper T cell- interprets a message (an antigen )presented at the surface of the cell membrane by MCH-II molecule. T cell will release many molecules of the protein interleukin-2 and after the series of processes in the cell there is a result -the production of many clones of the helper T cell. These indentical T cells can serve as a brigale forming an essential communication network to activate B cells, which make antibodies that will specifically attack the activating antigen.

http://www.hhmi.org/biointeractive/animations/tcell/tcell_print.htm

INFLAMMATION

Damaged to the body's tissues through heat, chemicals, sunburn, cuts, or microbial infecions trigger inflammation. Sings and symptoms of inflammation include redness, pain, heat, swelling, and sometimes loss of function. Inflammation has three main functions: to destroy the agent causing injury, to limit the effects to the rest of the body, and repair or replace damaged tissue. Damaged cells release several chemicals such as histamines,prostaglandins, and leukotrienes. Certain components of the complement system can also cause the release of histamine. One function of this chemicals is vasodilation and increase in a diameter of blood vessels. Vasolilation results in more blood and more phagocytes, nutrients, or oxygen is delivered to the site of injury. So, the increased of blood flow results in redness, heat, swelling, and some of the pain associated with inflammation. The increase of blood flow release phagocyte migration such as monocytes and nuetrophils to the scene. The phagocytes stick to the walls of the blood vessels called migration. Then squeeze throught the gaps between cells in the process called diapedesis(emigration). Within an hour, phagocytes begin to destroy the invading microorganism by phagocytosis. After engulfing the microorganisms and damaged tissue, phagocytes die forming phagosome. The final stage of inflammation is tissue repair. The increased of nutrients and oxygen from vasodilation aids the tissue. Other components of the blood heals the injury as well. I chose this video clip because in class we covered inflammation and functions of it. So, this clip is knowleagable and it is a good reminder of what we covered in class.

URL LINK: http://www.sbs.utexas.edu/psaxena/MicrobiologyAnimations/Animations/Inflammation/PLAY_inflammation.html

T Cells Dependent Antigens

The video about T Cells Dependent Antigens is related to what we've already learned in our microbiology class.
Proteins need the help of T-helper cells to make B cells into antibody-producing cells and memory cells. As the protein enters the macrophage, it gets broken into peptide pieces; the Class II MHC then moves it out of the macrophage. The T-helper cell starts working as the T-cell receptor, which is on the top of the T-helper, senses the peptide compounds coming from the macrophage. After that, T-helper cell can stimulate B cells. Same as the macrophage, B cells are capable of ingesting protein antigens; an antibody, which rests on top of B cells, interacts with the antigen which causes the antigen to get swallowed by the B cell in which it gets broken into peptides and then carried out of the B cell on a Class II MHC. As the Class II MHC of the B cell, which carries the antigen, acts with the T-cell receptor, the T-helper brings cytokines into existence. The cytokines then cause B cells to produce plasma and memory cells. http://www.1lecture.com/Immunology/T%20Cells%20Dependent%20Antigens/index.html