October 27, 2010, B-Cells and T-Cells

Today, we watched two short movie clips.

One was about the role of an antibody.

• neutralization
• aggulination
• precipitation
• complement proteins

The other was about:

• humoral immunity- provided by B-cells, defends primarily vs. bacteria and viruses present in body fluids
• clonal selection

Notes: Page 21, 23, 24
Clonal Selection

• When an antigen enters the body fluids, it binds with B-Cells that have complementary receptors
• The B-cells are then activated; they grow and divide, creating effector cells
• These cells then secrete antibodies specific to that antigen
• plasma cells- make the antibodies
• memory cells- "remember," this is why you don't get the same exact infection again because your body produced the antibodies needed to fight that infection

T-Cells

• Cell-mediated immunity
• Respond to antigens that have already entered the body
• More "hands on" than B-Cells
• 3 kinds- Helper T-Cells, Cytotoxic T-Cells, and Supressor T-Cells

Helper T-Cells

• Macrophages engulf a microbe, produce antigens, and displays the foreign antigens on the cell membrane
• it is essentially saying "I found something and I don't think it's good!"
• The Helper T-Cell binds to the macrophage at the site and determines if it is good or bad
• If bad, the Helper T-Cell divides, produces memory cells, and stimulates activity of cytotoxic T-Cells

Cytotoxic T-Cells (Killer T-Cells)

• Identifies infected body cells and binds to them
• Discharges perforin which is a protein that creates a hole in the infected cell's membrane, causing it to die.
• This needs to happen because the infected cell has become a factory of pathogens and the body needs to have it shut down.

Homework:

• UP pgs. 47 and 57
• UP pg. 5 What is Ecology Good For (E.C.)
• Work on Lab Report, Due: 11/8
• The Test may be on Tuesday, but please still plan on Friday!!!

Next Scribe:

• Claire T