Protists Flashcards
What is the immune response of humans against protists?
Most protozoa infections are harmless, but some can be detrimental to human and animal health i.e., Plasmodium
Protozoa may be phagocytosed by macrophages, but many are resistant as replicatr within macrophages
T.b. gambiense induce humoral response due to extracellular location
Leishmania use cellular defence mechanisms which depend on CD4+ T-lymphocytes –> Macrophages –> Th1 cytokines
Plasmodium has diverse defence depending on Ag and protozoan location. So can be cellular or humoral
Tell me about duffy antigens and malaria
Duffy antigen is located on the surface of RBC
They produce IgG subclass antibodies
It is also a receptoe for P. Vivax
Duffy-negative individuals are resistant to P.vivax infection
Define definitive host
The definitive host is the one which harbors the adult parasite and where the parasite reproduces sexually.
Define intermediate host
The intermediate host is the host which harbors the larval stage or the asexual forms of the parasite.
What is a type I hypersensitivity reaction?
Involves IgE against soluble antigen
Results in mast cell degranulation and the release of histamine and other inflammatory mediators
B-cells stimulated by CD4+ Th2 cells –> IgE produced (these can be systemic or localised)
Pathogenesis of malaria?
Anaemia
Acidosis
ruptured blood cells –> release toxins –> activate peripheral blood mononuclear cells –> stimulate release of cytokines, growth factors and other effector molecules which determine the severity
What is the prevention and control for toxoplasmosis?
- Avoid drinking untreated water
- Wear gloves when gardening as could come into contact with cat faeces which contains toxoplasmosis
Pathogenesis of toxoplasma?
The two critical intracellular stages of T.gondii are the rapidly circulating tachyzoite stage and slow growing bradyzoite stage
Different symotoms of toxoplasma?
Treatment?
Healthy person: Flu like symptoms
Mother-to-baby (congenital): Can cause miscarriage, still born or child born with congential toxoplasmosis which is where they have an abnormally large or small head
TREATMENT: Pyrimethamine
Prevention and control for African Trypanosomes aka sleeping sickness
- Cover exposed skin
- Avoid bushes
- Insect repellant
Pathogenesis for african trypanosomiasis?
Two stages: Haemo-lymphatic and CNS stage (able to cross BBB)
parthogenesis; B-cell proliferation first in lymph nodes then the brain and meninges and this response can lead to tissue damage
symptoms: fatigue, anxiety, motor, sensory and neurological problems, myocarditis and hypogonadism
Pathogenesis for south american trypanosomiasis
T. cruzi
Triatomine bug
two phases
Acute: Parasite in circulating blood, Mild or asymptomatic, fever or swelling
Chronic: Heart rhythm abnormalities can lead to sudden death, dilated heart that can’t pump blood well, dilated oesophagus or colon which can lead to problems eating or passing stool
What effect do wolbachia have on mosquitoes and how?
Reduce their ability to transmit viruses like Zika, Chikungyun and yellow fever by…
- cytoplasmic incombatability
- Pathogen blocking
- Life shortening
What is Wolbachia pipentis
A vertically transmitted obligate intracellular symbiont of arthropods
Why are model organisms good for drug testing?
- Easy and cheap to maintain
- Phylogenetically related
- Conserved neurobiology
- Genetically tractable
- Suitable for high through-put chemical screening
- Suitable for delinating mode of action
