Fight for your Life! A Short Story about the Immune

System

Once upon a time on the planet we call Earth, there existed thousands and thousands of microorganisms. Just like people, there were good and bad microorganisms. The bad microorganisms, the ones that caused disease, were called pathogens.

Who should be the main pathogen in our story first?

Bob, the bacterial pathogen!

Vinny, the viral pathogen!

Bob the bacteria needs to find a new home that will provide him shelter and nourishment. So, who better to find a home in than YOU! One day Bob tries to invade you, but luckily you have your first line of defense: your skin! Your skin helps guard the body’s internal environment.

But, Bob the pathogen is smart, and he knows that your skin is not perfectly secure. There are other openings to the inside of the body that he can sneak in. However, these openings are hard to get through. They are lined with saliva, tears, mucus, and sweat. This is known as your second line of defense.

Hmmm, this looks likea good spot to sneak in!

Bob got stuck in the mucus lining the nose, and decided to go back the way he came from. He tried one last opening, in an open cut, and BAM! He was inside your body!

Goodbye nose! Hello open wound!So nice to see you today! Hahahaha (maniacal laugh)

Bob was able to enter the bloodstream through the cut. He received a warm welcome from your body’s third line of defense: Macrophages! As soon as the Macrophage saw Bob, it ate him right up. As the story goes, Bob did die . But, the good news is your body stayed healthy.

Bob-0 Your Body-1Winning!

Om, nom, nom!

What do you think about Bob?

• Was the body’s defenses (the skin, mucus, and macrophages) specific to Bob? In other words, would they only kill Bob the bacteria, or do you think they defend against ALL invaders?

• You’re right. The body’s defenses were NOT specific to Bob, which is why they are called nonspecific barriers.

A real life example of Bob.• Bob represented a bacterial pathogen. A bacterial

pathogen you may be familiar with is E.coli. • E. coli is found in human waste, and if it enters the

body/bloodstream orally, it can have detrimental effects.

• E. coli and other bacteria can cause dysentery that results in severe diarrhea containing blood and mucus in the feces, with fever and abdominal pain.

Acne is caused by bacteria too! http://www.sharecare.com/health/acne-skin-pimples/what-bacteria-cause-pimples

Vinny the virus comes alive when he invades humans, and he is looking for his next victim! Vinny is a master of disguise and was able to get into your body through your nose, no problemo. However, as soon as Vinny entered your body, your immune system was ready to put up a fight!!

As soon as Vinny the virus entered your body, your specific immune response was triggered because Vinny is a recognizable guy! The Macrophages(cells that eat toxins and diseases) are the generals in our immune army, and they are calling on their recruits, the Helper T Cells, to get rid of Vinny.

Attention! Calling all Helper T Cells!Let’s get rid of Vinny!

The Helper T Cells realize they can’t kill Vinny on their own, so they send a secret message into the bloodstream asking other cells to assist them. The message says lymphokine in cell language (this translates to SOS in English). The Killer T Cells intercept the message, and they are coming to the rescue!

Help! Help!We willHelp you Fight this battle!

The Killer T Cells recognize Vinny the virus and the cells he already infected. The Killer T Cells do their job and destroy Vinny and the infected cells. You immediately to start to feel better because Vinny the Virus is a goner!

What do you think?• Is the type of response you just read about

cell-mediated or antibody-mediated?• You’re right. It was cell-mediated because lots

of cells are involved, but no antibodies!

Macrophage

Real Life Example of Vinny

• The Flu Virus (Influenza virus)https://www.youtube.com/watch?v=Rpj0emEGShQ

What type of cellate the flu virus?

Now, it’s your turn!• You are your partner

are going to create a children’s book on the antibody-mediated response.

• Use the bottom of page 311, the pictures on page 312, and explanation on page 313 to help you!

• Get started now by picking your bacteria or virus!

PathogensAntibody

Group of Antibodies

Brainpop!

• http://www.brainpop.com/health/bodysystems/immunesystem/