Parasitic symbiosis can use immune system flashcard to hel with answer specifically how parasites maniulate immune system card

Parasitism Is

• One organism (the parasite) benefits and the other (the host) is harmed.

why can’t parasites take everything from the host?

The parasite has to have a balance of not taking everything from their host cus they’ve to take just enough and not kill it until it’s achieved everything it wants to achieve

What makes a parasites Apicomplexan

if they’ve unique structure within the cell called apicalcomplex, which is made up of smaller components but their primary function is to help parasite invade its host

Explain what the protective coats (thick outer coating)do

They form protective coats around infected cells which forms a protectective environment protecting it from desiccation and temperature and allow parasites to survive an environment for an extended period of time

How do parasites manipulate host cells

Remodel cytoskeleton in order to Manipulate the cell structure

Interferes with apoptosis preventing cell from getting rid of infected cells

Alters cellular metabolism to gel direct nutrients they need to replicate to produce more parasites

Toxoplasma is what type of parasite and related to ?

Coccidan parasite and related to plasmodium

The only host toxoplasma can reproduce sexually is?

Gut of a cat is definitive host

Toxoplasma is a Major problem for what type of people

Pregnant women immuno-compromised individuals especially AIDS patients, transplant patients

what happens when the parasite toxoplasma gets into a cell

it’ll replicate out of those cell and burst out of them, damages cells as its going through their life cycle

what tissues is it common for toxo plasma parasites to form cysts in?

muscle and brain tissue

what type of cyst can toxo plasma parasites form and where

they form protective cysts in tissue

Explain life cycle of toxo plasma in the context of cats and mice

• mice is infected by an oocyst

• they infect mice to by changing their brain chemistry and behaviour to be less afraid of cats.

• cats eat mice and the parasites sexual phase happens in cats guts,

• parasites cells are shared into the environment by cat faeces

• from there they can be picked up from other animals and humans

what is an oocyst

is a protective cyst, that is packed with sporozoites they stay within tissues and persist through environment for long periods highly resistant to heat, cold

How can humans be affected by toxo plasma

Is by infected muscles. We can form cysts inside the muscles of animals that we consume as food, particularly if you haven't cooked things, there is a risk that you haven't killed off the sets.

What measures is important for pregnant women to prevent them having toxo plasma

• not eating undercooked meat.

• careful when changing litter trays

• If you’re working in the garden wear gloves and be careful washing hands after gardening

• clean veggies effectively

Why do we have to clean veggies thoroughly

Because if there’s oocysts in the soil, they can attach themselves to these vegetables.

how can toxo plasma be transmitted during pregnancy

the parasite is capable of crossing the placenta and infecting the foetus

Different forms of toxoplasma

– Oocysts

– Sporozoites

– Trophozoites–

Tachyzoites

– Bradyzoites

what is a Sporozoites

– Infective cells

– Invasive form of toxoplasma

– rapidly develop into tachyzoites upon infection

what is the challenges of creating a treatment for toxoplasma

Different forms of toxoplasma all have slightly different biochemistry, They all activate slightly different genes. So they all behave slightly differently. Because things like the biochemistry is changing, we can’t always target each form as effectively and If we leave any of these forms around in the host, we continue to cycle again. Same thing applies for malaria

what is a Tachyzoites

– rapidly multiplying stage of toxoplasma

– capable of developing into cysts

– capable of infecting the foetus via bloodstream

What is a Bradyzoites

– slow growing

– can form cysts which lead to chronic infection

– Primarily found in brain and muscle tissue

Humans infected by toxo in 2 ways

– ingestion of undercooked meat

– Ingestion of contaminated cat faeces

the eye and the brain is often infected with toxo, particularly if you are infected while you are in utero,

toxo does what to eyes

It impacts the cells of the retina.ultimately that replication cycle. Destroying those cells destroys the cells in the retina, leading to blindness.

how can toxo plasma become a progressive disorder in the eye

because although the act of infection has died down, we still have some of those cysts and cells remaining, They can reactivate. So it's often progressive

what happens if you are infected by toxoplasma during pregnancy

can lead to miscarriage, it can form cysts in the brain, leading to developmental problems in the foetus

The more severe the symptoms are from toxoplasma in

A. Later pregnancy

B. Earlier pregnancy

B. Earlier

Why is there more severe symptoms during early pregnancy than later when iinfected by toxo

in those early stages, it's very much about development changing as you're getting into 3rd tri most of the growth and most of the sort of developmental stuff is done.

Behavioural effects and brain changes by toxo

They impact, the biochemistry of the brain in humans and animals depending on location of the parasite in the brain and sex of the host.

Parasites can differentiate into slow growing bradyzoites and form cysts in the brain

They can change behaviour because lots of the neurochemicals inside our brain influence our behaviour.

Mice infected with parasite lose their fear of cats why?

scientists found is things like the smell of cat urine, which would normally made rodents move away from that particular scent. That was no longer the case. What they have been able to establish is that the parasite is manipulating the brain chemistry to enable the mouse to be less scared. More likely to be prey for the cat to eat. Therefore, the parasites completed its life cycle to sexually produce in the cat gut.

What are theories on the impact of toxo in humans in our brain chemistry and neurological conditions

we do know that things the levels of dopamine are impacted in an infected individuals.

Still discovering if individuals might develop riskier behaviour

how can toxo plasma change dopamine levels in humans

cus it has an enzyme that's involved in the process of converting the amino acid tyrosine into dopamine

what is the result of toxo affecting a neurotransmitter

just by impacting one neurotransmitter, we have the potential to impact a massive number of different processes.

toxoplasma impacts what else in the host that isn’t brain chemistry

alters the host immune response

How does toxo alters the host immune response

Toxoplasma is able to protect itself from the immune system, but it's also very clever in that if the host gets an infection. It doesn't want that something else to kill the host either. is not just protecting itself, but it's actually manipulating the immune system so that the host doesn't get killed by something else.

how do parasites alter the host immune system

It doesn't want to be killed or taken out by the host before completing its life cycle. It will want to turn off the host immune system Or manipulate it so that it doesn't kill the parasite. as the immune system is how the host gets rid of foreign entities

malaria life cycle

is transmitted among humans by female Anopheles mosquitoes

replication of parasite occurs inside the mosquito gut

The mosquito bites its host and transfers parasites through the saliva as it's taking the bite.

once it gets inside the host, we've got two main areas where it replicates inside human

in the liver

once the replication happens in rbc’s

these parasites are then picked up the next time a mosquito bites a human and sucks up some blood

name the different species cause malaria

– Plasmodium falciparum

– P. vivax

– P. malaria

– P. ovale

malaria is from what parasite

plasmodium

what’s the replication of malaria in humans liver like

initial replication inside the liver.

release infected cells are released from the liver which then infect red blood cells

The parasite replicates inside the red blood cells burst out into the bloodstream, infecting red blood cells, and the cycle takes place again.

And these parasites are then picked up the next time a mosquito bites a human and sucks up some blood

majority of replication of malaria takes place where in humans

red blood cells

fever symptom of Malaria is caused by

when the parasites burst out of the red blood cells.

you get a fever.

it infects cells.

he fever disappears the next time they burst, right, we get fever again.

How can we identify what type of malaria someone has

the reoccurrence of getting a fever and other symptoms occur is one of the things that helps identify the type of malaria it is because the different species have slightly different patterns in terms of their replication

Factors That Determine The Occurrence of Malaria

The parasite (malaria)

the vector

the host

All of these components have to be together in the same place for malarias life cycle to be complete and for it to replicate and spread.

if one of these elements is missing we can break the cycle

Which human mutation provides protection against malaria in regions with high mosquito prevalence?

The sickle cell trait offers protection against malaria. This occurs due to a single point mutation in the haemoglobin gene. While sickle-shaped red blood cells are more fragile, this trait disrupts the malaria parasite’s lifecycle. The red blood cells collapse under stress, preventing the parasite from replicating and growing.

How does malaria affect heterozygous individuals with sickle cell?

If you are a heterozygote have that protective, aspect against malaria

Mutation that protects you from malaria

glucose six phosphate dehydrogenase an enzyme is part of the phosphate pathway. If you've got a mutation in that enzyme, it also protects you against malaria.

what is a constraining factors for the relationship between the vector the mosquito and the parasite

the environment, but that can change due to climate change

factors important for mosquitos to grow

temperature and humidity

why is the mosquito life longevity important for spreading malaria

relying on the mosquitoes living long and is mature enough enough to be able to bite someone, to grab a parasite and then bite someone else and transfer the parasite before it dies.

How plasmodium aka malaria invade the human immune system

from a human perspective, we're manipulating many of the same pathways that Toxoplasma manipulates.

we're switching off apoptosis

manipulates cytokines so that we're not producing aspects of the adaptive response so we are not produce the antibodies to get rid of it.

Why don’t anti malaria drugs work

cus parasite is constantly changing

how did the malaria parasite gets around the changing immune system

Its antigenic diversity and the changing how it looks is way that the parasite can manipulate the immune responses. It does this cus it knows the human adapts and recognises it and gets an immune reaction

areas they’re looking into to prevent bacteria

cus we know the issues with drug resistance we are looking into the symbiotic bacteria in mosquito as it impacts transmission of parasite, to possibly prevent transmission, reducing the growth of the parasite inside the mosquito host.

How does the parasite manage equilibrium with the mosquito

The parasite has to balance out, taking what it needs, but still allowing its host to survive, in order for the mosquito to finish the life cycle.