Malaria in the Immune System
By: Lindsay
What is it?
- Malaria is a disease that is transferred
usually by mosquito
- The mosquito passes on parasites that
it contains in it’s own system. The
parasites are passed into the blood
stream.
Symptoms
Protection
- Immune protection against malaria requires
continued exposure
- People who get effected by malaria in a “risk
zone” and then leave, are more apt to get it
when they return to a risk zone
- Immune system needs the parasites to be in
the body for an amount of time so that they
can produce antibodies and combating cells
to fight of the disease
- Risk Zones include: Africa, Central American,
Mexico, South America and Southern Asia
Effects on the Immune
System
- Immune system defenses include:
antibodies, lymphocytes, monocytes,
macrophages, natural kill (NK) cells and
neutrophils
Antibodies
-
neutralize the parasites
Stunt parasite development
prevent them from entering target cells
help macrophages to engulf the
parasites and infected cells.
NK Cells and Neutrophils
- First line of defense against malaria
- Macrophages attack the malaria
infected cells, along with infected RBC,
and engulf them
- Macrophages eventually clear parasites
from blood stream
Cellular Immunity
- Considered very helpful in the
prevention of malaria
- Cytokines are also helpful to prevent
malaria
- This chemical is secreted by
lymphocytes
- They enhance the process of cellular
immunity
Malaria in the Liver
-
causes the liver to become enlarged
Becomes firm and tender
Parasites travel to the liver first
This is where they change to a new form that
can effect red blood cells and cause them to
burst (decreases RBC count :/)
- Parasite cells accumulate calcium ions that
disguise the infected cell so the immune
system doesn’t “see” the infection right off
QuickTime™ and a
decompressor
are needed to see this picture.
Parasite-filled merosomes (green)
move from an infected liver cell (pink)
into a blood vessel full of red blood
cells but avoid being 'eaten' by white
blood cells of the immune system
(blue).
Credit: Science
Red Blood cell
bursting after
Malaria
infection
Problems
- Malaria parasites presents a different group
of targets (antigens) to the immune system
- Malaria parasites mutate rapidly generating
different variant
- This ability to generate different forms and a
diversity within targets of the host's immune
system help the parasites to bypass malarial
immunity.
- Parasite diversity makes it difficult to create a
vaccine for malaria because the parasites
changes so one vaccine might not effect
diverse malarial parasites
Extra Facts
- Malaria kills more than 3,000 children
under the age of five per year
- More than 1.5 million/year
- Infection rate of approx. 400 to 500
million/year