Malaria is weird.
I just summarized the life cycle of malaria in 3 twitters. I'm so cool.
Anyway, if you're curious, it's as follows:
First off: Sporozoite, merozoite, gametocyte, and zygote refer to various stages of the malaria parasite. A hepatocyte is a liver cell.
A mosquito bites a person and transfers in (a) sporozoite(s). The sporozoites circulate in the blood for 30 minutes or less, enter hepatocytes in the liver, multiply & develop into merozoites there, and lyse (break) the cells to enter the bloodstream. From there, they enter red blood cells (RBCs), and multiply until the RBCs break open (lyse). Repeat this step. Symptoms develop here, and they cycle every 48 hours or so, because that's how long this portion of the cycle takes. It's also why people with malaria become anemic and have enlarged spleens -- the spleen deals with pieces of blood cells.
Anyway, after all that the parasites develop into gametocytes while in the bloodstream. A mosquito bites the unfortunate victim, and picks up a few gametophytes. In its salivary glands (eew), they grow into gametes, form zygotes, and multiply and develop into sporozoites. Then the mosquito bites a person and we're back at the beginning.
It's pretty hard for the immune system to attack something like this. Usually, the adaptive immune system (antibodies, B and T cells, etc -- basically, stuff specific to antigens) gets ahold of a particular protein or something that invaders put out on their surface. However, malaria *changes* so many times it's hard to catch -- and even then, the antibodies can't get to it while it's in a cell, only while it's in the bloodstream. Even when the right antibodies *do* get out there, the parasite gets rid of its protein coating, so they end up attacking an empty coat thing and not the actually harmful pathogen.
Anyway, I think it's neat how this organism has evolved to so effectively reproduce in something else's body, in an organism that really has a pretty good immune system, without really altering the immune response at all, just hiding from it. I'd love to study parasite evolution. There's some interesting things different bacteria do, as well, but if I started in on that I'd be too interested to go to sleep, and I really should get around to that.
Anyway, was that whole ramble hard to follow? Any jargon I didn't define, or other confusing things I can maybe help explain?
Did I bore you out of your skull? Inquiring minds want to know.
Anyway, if you're curious, it's as follows:
First off: Sporozoite, merozoite, gametocyte, and zygote refer to various stages of the malaria parasite. A hepatocyte is a liver cell.
A mosquito bites a person and transfers in (a) sporozoite(s). The sporozoites circulate in the blood for 30 minutes or less, enter hepatocytes in the liver, multiply & develop into merozoites there, and lyse (break) the cells to enter the bloodstream. From there, they enter red blood cells (RBCs), and multiply until the RBCs break open (lyse). Repeat this step. Symptoms develop here, and they cycle every 48 hours or so, because that's how long this portion of the cycle takes. It's also why people with malaria become anemic and have enlarged spleens -- the spleen deals with pieces of blood cells.
Anyway, after all that the parasites develop into gametocytes while in the bloodstream. A mosquito bites the unfortunate victim, and picks up a few gametophytes. In its salivary glands (eew), they grow into gametes, form zygotes, and multiply and develop into sporozoites. Then the mosquito bites a person and we're back at the beginning.
It's pretty hard for the immune system to attack something like this. Usually, the adaptive immune system (antibodies, B and T cells, etc -- basically, stuff specific to antigens) gets ahold of a particular protein or something that invaders put out on their surface. However, malaria *changes* so many times it's hard to catch -- and even then, the antibodies can't get to it while it's in a cell, only while it's in the bloodstream. Even when the right antibodies *do* get out there, the parasite gets rid of its protein coating, so they end up attacking an empty coat thing and not the actually harmful pathogen.
Anyway, I think it's neat how this organism has evolved to so effectively reproduce in something else's body, in an organism that really has a pretty good immune system, without really altering the immune response at all, just hiding from it. I'd love to study parasite evolution. There's some interesting things different bacteria do, as well, but if I started in on that I'd be too interested to go to sleep, and I really should get around to that.
Anyway, was that whole ramble hard to follow? Any jargon I didn't define, or other confusing things I can maybe help explain?
Did I bore you out of your skull? Inquiring minds want to know.