Germs are like wangsters (wannabe gansters).
Most of the time, they don’t trespass the little white picket fence (barrier: skin, mucous, acid).
This is the first line of defense.
But when some wangsters are triple-dog-dared to trespass, they do, and that’s when the second line of defense kicks in.
During an Inflammitory response, Histamine and his good friend Prostaglandins work together to vasodilate the blood vessels so that phagocytes (Cops) can rush in.
Chemokines, the residents of the area that live in the blood vessel endothelium call the cops in, and Pyrogens, which are hot women, (hot cause they raise our temperatures) make it difficult for microbes to concentrate on functioning properly.
Because of budget cuts, the cops come to the crime scene in taxis (chemotaxis).
There are 2 kinds of cops: good cop and bad cop.
The good cop is a Neutrophil, which dies a few days after engulfing microbes.
The bad cop goes trigger happy and Transformers on us and turn into Macrophages, which extend pseudopods and wage a chemical warfare by using 2 funky toxic forms of oxygen: superoxide anion and nitric oxide, along with lysozymes.
They eat and eat and eat microbes for a long period of time until they explode from eating too much, and then they become part of Puss, which is comparable to mass grave sites, I suppose.
Complement is a bunch of proteins that make invading cells POP.
Interferons put a “kick me” sign on the backs of microbes so that Natural killer cells can see it and kick butt.
Then, the third line of defense kicks in, and this time, things are getting specific.
Stem cells in the bone marrow grow and differentiate into different cells. That is high school.
But some students go to a community college near home—they stay in the bone marrow to become B cells.
Others go to ThymusUniversity and become T cells.
These B and T cells patrol the very important buildings called blood, lymph, and lymphatic tissue.
B cells find it Humoral (response) to make antibodies to fight against a mafia-like gang called Disease. But sometimes they need to be told to work (stimulated) by T cells or they jump to work when the encounter well known juvenile delinquents: Virus and Bacteria.
T cells, like Lawyers (?) want to make sure that there are prosecuting the right guy and don’t kill until the Antigen presenting Cell shows evidence that “THIS CELL IS CORRUPT” by displaying foreign antigens on the surface.
Cytotoxic T rex cells KILL (eat?) infected cells because they have antigen receptors that can sniff out the foreign antigen that APC MHC1 displays. When the Cytotoxic T rex binds (bites?) into the mhc1, a CD8 protein holds the t rex and ACP (?) together until the T rex cell is activated and wants to go on a killing spree (kinda like that shark in finding nemo. Once he got a little sniff of blood, he wanted MORE!!) And the T rex cell makes more of itself and differentiate into plasma and memory cells. T rex cells kill by chemical warfare too, using perforin.
Helper T cells is like the woman to screams OH MAH GAWSH WE’RE BEING INVADED! AHHH! IMMUNE SYSTEMS GO!Their receptors bind to protein fragments displayed by MHC 2 and a CD4 protein holds the two cells together until the helper is activated. Then, it too proliferates and turns into plasma and memory cells.
The helpers help stimulate other T cells and B cells by releasing cytokins and interleukin 1 and 2.
MHC’s are AKA HLA. Heres a little almost rhyme to remember where theyre found:
MHC 1 is on all (nucleated) cells
MHC2 is on a few (rhymes with TWO!!) specialized cells (macrophages, b cells, t cells) In Clonal selection, Antigenic Molecules pick (bind to) a select few, specific B or T cells (like during the Great Depression, jobless men would gather round, hoping to be picked for the day job)
Once the workers are selected, they get categorized and given jobs called “Plasma Cell” and “Memory Cell”
Plasma cells, sadly, don’t live very long. They get KIA during the Primary Immune response when they fight antigens.
Lucky for those who get to be memory cells, though, because they get to live loooong lives and die of old age :] They never forget a face because they have Immunological Memory. I call it long-term memory! :D same diff…, so when the same juvenile delinquent comes around again, the body knows exactly how to kick its butt faster. (secondary immune response)
Macrophages like to do APC’s job and present fragments (oh, maybe like the criminal’s arm or leg or… NOSE HAIR) of the invader on the cell surface using MHC2. A helper T goes OOHH…MHC complex…..-toouuuchh- and gets activated. It starts to see double then quadruple then…8-iple vision! There are soon thousands of itself who all celebrate their creation by throwing cytokine confetti in the air. The confetti makes T cells and B cells work more cause they’re happy to work and kill and fight infections.
Antibody’s real name is Immunoglobin. They’re so anti social that theyre socially awkward and ask “Y” all the time. Their why questions have 2 heavy parts and 2 light parts, 4 constant, and 4 not constant (variable) regions.
If misery loves company, then antipeople love antigens and, so, antigens are found the the Y’s of the anti body people.
G-MADE (Gaby-MADE/created) antibodies (whose real name is immunoglobin, did I mention? :P) kill antigens in 2 ways.
Way one is to disarm the enemy (neutralize) and clump em into a complex named after both the antigen and antibody: antigen antibody complex. And the our Big-bad-cop-turned-macrophage EATS the clump. YUM.
Way two: the Gaby Made antibodies signed a treater called Complement Fixation with the sorority/fraternity complement. The Complement does its job and make the bad guys go POP (like popcorn!) Passive immunity will soon pass away. It doesn’t stay around very long. It doesn’t stick around as a life-long friend because it knows that you didn’t make it (he feels sad cause this kind of immunity was ADOPTED!) the antibodies were injected into the person to fight the disease. Or, the antibodies in the mommy milk is drunk by the baby and the baby gets immunity for a little bit. BUT THAT’S NOT ALL, FOLKS! The GGinjection (gamma globulin) can grant passive immunity too.
If you want to be immune for a life time, stay active in making your own antibodies. Either after getting infected or getting immunization shots—you can make them yourselves. Its really easy and it saves you money! SO easy that you can DO IT AT HOME! For FREEEEEEEEEE!(does it? I don’t know. Making things yourself always seems to save something)
The first exposure to a vaccine gives a primary (“first”..cause its first, duh) response and is followed by a gradual decline of the antibody level.(its not gonna jump off the mountain. Its gonna climb down slowly..or hike down. Whichever.)
Then the second exposure gives a sescondary response, which kicks butt faster because it KNOWS the face of these delinquents. And so the RIGHt anti personnels go out and kill faster until sickness is gone. And because these antipersonnel/bodies are your OWN, they don’t gotta run away from HOME and they stay with you for evers and evers and support you even when you’re old!
UH OH. ACHOO! I’m hypersensitive to dust! Achoo achoo! This allergens make me destroy my tissue box. (cause they usually involve tissue damage. Lawl?) It feels like ive got a COLD. The second line of defense is kicking in and Histamine is making me Itchy, Reddish, Runny, Coughy, and Sneezy. (not 7, but 5 dwarfs? :P) Allergens aren’t wangsters. Theyre GANGsters who break into homes.(blood stream). Ana and Phil act shocked! Ana faints, dropping their babies Press and Sure, to the floor. (blood pressure drops).
Delayed responses are started up by memT cells. The response has a supervisor called Cytokine, who was hired from T-Mac (cytokines secreted by t cells an macrophages), a very reliable company.