02/17/11

• AIM: Why is HIV so dangerous ?• DO NOW: What does your body

“PRODUCE” (make) to give you immunity?

Pathogenic diseases•Disease caused by _____________(living

organisms).•Pathogenic diseases are infectious or

_______________•Ex_____________

•___________________

White Blood cells• Are of 3 types• 1)____________________________________

_____________________________

• 2)_________________

Three types of White Blood Cells• Macrophages (the ‘big

eaters’)

• T cells andB cells (Lymphocytes)

• There are different types of T cells and B cells

How do macrophages ‘EAT’

• By ______________• The process is called

__________________• So we also call them

_________________

• T cells

• B cells

Different types of T and B cells

Helper T cell

Killer T cell

Plasma B cells

Memory B cells

• Who is this?

ANTIGEN

• Protein marker on the ____________________________________• RECEPTORPresent on______________________________Receptors help ___________________________

_____________________________________

What makes your immune cells recognize the foreigner?

• A foreigner is recognized by the presence of ANTIGEN on its surface.

• T and B cells have receptors to recognize the antigen

• How?• On the surface of each

lymphatic cell (T cell and B

cell) are receptors that enable them to recognize foreign substances.

• These receptors are very specialized – match only one specific antigen.

• The body makes many different types of lymphocyte cells so that the immune system can recognize nearly all invaders.

• Could be a T or a B cell 

ANTIBODIES

• Y-shaped proteins made by ___________________

Against specific _________________________

• But the really cool thing about the immune system is that it has the ability to "remember" enemies that it has fought in the past. If the immune system detects a "registered" invader, it will strike much more quickly and more fiercely against it. As a result, an invader that tries to attack the body a second time will most likely be wiped out before there are any symptoms of disease. When this happens, we say that the body has become immune.

• Bacteria and Viruses: Our Main Enemies• A virus needs a host cell to reproduce. • Now that you know a bit about our

defenses, let's take a closer look at our primary enemies. Bacteria and viruses are the organisms most often responsible for attacking our bodies.

• Most bacteria are free living, while others live in or on other organisms, including humans. Unfortunately, many bacteria that have human hosts produce toxins (poisons) that damage the body. Not all bacteria are harmful, though. Some are neutral and many are even desirable as they fulfill important functions in the body.

• Bacteria are complete organisms that reproduce by cell division. Viruses, on the other hand, cannot reproduce on their own. They need a host cell. They hijack body cells of humans or other species, and trick them into producing new viruses that can then invade other cells. Frequently, the host cell is destroyed during the process.

• We find and "eat" bacteria, viruses, and dead

or injured body cells…um Yummy!

Some of us have gone really bad and make trouble…we can make poisons/toxins that damage the body

I wish I could sneak in ____ ______ without being recognized by those stupid immune cells...sigh!

Damn it! The protein on my surface gives away who I’m and alerts those scary looking _________ cells who can eat me alive or throw nasty weapons

called ___________ on me.

My job is to take the first step in the event of attack.

•I make trouble

Well, I’m a foreigner…but I so badly want to live inside that yummy body

No entry please, first you need to get through me…

We defend the whole body… we make the defense force

I make the enemy look appetizing for eater cells (macrophage)…

I triggers a reaction from the immune system

I travel through your body until I find an antigen of the right size and shape to match my specific receptor

• My only job is to activate B cells and killer T cells.• My job seems simple, but guess what, B cells and killer T cells can do nothing if I

don’t inform them of the invader• When I see (with the help of my receptor) a phagocyte who has just eaten a

foreigner/invader, I get hyper!• I can tell which phagocyte has eaten a foreigner because there is a part of it

sticking out! • I’m a martyr…I present the foreigner to the Helper-T cell and then B cells and

killer T cells kill me because I’m infected…u think its fair? • Hi, we make the army of higher rank…we are specialized

• I can not only recognize a foreigner…I can tell exactly who it is. Thanks to my special receptors! Oh well, the only problem is that I only have eyes (I mean receptors) to recognize one type of foreigner…but my other buddies can recognize others..

Once I find an antigen (enemy! Intruder! A foreigner!) that matches my receptor, I’m on it. I’ll make 2 special cells: one to make weapons, and the other to remember the intruder…

I don’t take any chances…I will kill you even if you are one of our own just because you look sick and infected with pathogens

We help and we kill too…

Why is HIV virus so dangerous?

AIM: Why is HIV virus so dangerous?

• HIV virus attacks the helper T cells and brings down the whole immune system.

• Copy

Helper T cell

HIV Virus

How does AIDS kill you?• Acquired immune Deficiency

Syndrome• People with AIDS die because

their _____________________ is weak and they

can’t fight infections

• They die of diseases like Pneumonia, Meningitis, etc., which are caused by bacteria

• copy

Let’s start with a story…

In 1796 an English physician, Edward Jenner, attempted a very famous and risky experiment. In those days people used to

die of a deadly disease called smallpox, and there was no cure for it. Jenner noticed that

people who worked in farms with cows, almost never contracted the deadly disease smallpox. They however would get sick with

a milder disease called cowpox, which somehow protected them from getting

smallpox. Based on this observation, Jenner took an eight year old boy and infected him with cowpox (milder disease). When the boy

recovered from the disease, he now infected the boy with the deadly disease,

smallpox. The boy did not get sick! Did cowpox protect the boy from smallpox?

How could a previous illness protect a person from getting sick again?

• HOW DO VACCINES WORK???

Immune system

• Made up of Immune cells (White Blood Cells)• And lymphatic organs; spleen, tonsils, and

thymus• WBC are of three types• Macrophages (or phagocytes), T cells and B

cells (also called lymphocytes)

Three types of White Blood Cells• Macrophages (the ‘big

eaters’)

• T cells and• B cells

• There are different types of T cells and B cells

A B

A

2nd attack

Vaccination • Injection has ____________ _____________• Pathogen triggers (starts)__________________

• ____________________ are made

• Next time when the real _________________ enters the body ___________________ recognize it and initiate (start) _________________ production against the ______________ giving us ___________

• _____________(resistance)

Vaccination gives us____________And this type of Immunity where body makes its OWN

_________________ is called ACTIVE IMMUNITY. Since memory cells stick around for a long time, it is a

_____________term IMMUNITY.

PASSIVE IMMUNITY• When you get an INJECTION of the

_________________ to fight against a disease.• Gives you short-term IMMUNITY (protection)

against the disease.

Acquired immunity