Written exam

Question 1

How do cells of the innate immune system sense pathogens? Give one example how innate immune cells can recognize pathogens.

Answer 1

The innate immune cells carry pattern recognition receptors which are found on the cell membrane, cytosol and endosomal membrane. They can bind to the cell wall or the DNA/viral RNA to detect the pathogen.

Question 2

What does recognition of a pathogen by an innate immune cell typically lead to?

Answer 2

Natural killer cells can recognise infected cells and tumors and can induce apoptosis in these cells and they also release cytokines. Mast cells can release histamine, initiate inflammation, release cytokines and carry enzymes that can kill bacteria. Dendritic cells responds to microbes by producing cytokines, initiate inflammation and stimulate adaptive immune responses. Neutrophils travel around the bodies fluids but can also enter tissues at sites of infection where they can perform phagocytosis to destroy microbes. They can only survive for hours in tissues and act only as first responders. The cytokines will cause a release of neutrophils from the bone marrow and monocytes who travel through the bodies fluids will mature into macrophages in response to the cytokines where they can destroy microbes.

Question 3

Immune cell effector functions Macrophages

Answer 3

Phagocytosis (and antigen presentation)

Question 4

B Cells

Answer 4

Antibody Production

Question 5

Cytotoxic

Answer 5

Enhancement Of Epithelial Barriers

Question 6

T Cells

Answer 6

Killing Of Virus-infected cells

Question 7

Dendritic cells

Answer 7

Antigen Presentation

Question 8

1.Which kind of antigens are presented in which MHC molecule? To Specify:where do the antigens originate from, that are presented on either MHC class 1 or 2?

Answer 8

MHC class I is found on all nucleated cells in the body. Class II is only found in dendritic cells, macrophages and B cells.

Question 9

Angen-presentaonon either MHC class 1 or class 2 leads to the acavactivation of two different types of T Cells. Describe which T cell type recognizes antigens which MHC molecule.

Answer 9

Class 1 presents antigens to cytotoxic T cells and class 2 presents to helper T cells.

Question 10

he two T cell types differ fundamentally in their effector functions. Describe The Most important effector functions Of the two cell types

Answer 10

Cytotoxic T cells can induce apoptosis in cells. T helper cells prevent damage to tissues by limiting immune response reactions.

Question 11

Malaria true or false The most widely used treatment malaria was found in Chinese Traditional Medicine

Answer 11

True

Question 12

Malaria true or false In some areas in Africa, a genetic mutation is common that can cause severe anemia in individuals who are homozygotes but can protect against severe malaria in heterozygotes.

Answer 12

True

Question 13

Malaria true or false Blood Smear Microscopy Can Be Used To Diagnose Malaria

Answer 13

-True

Question 14

Malaria true or false: An important measure for malaria prevention is vaccination

Answer 14

-False

Question 15

There are many different types of human viruses that all have a specific life cycle from infecting the cell and spreading to another human host. Compare three different types of viruses and explain how their specific characteristics can explain the type of disease they cause,how they transmit between humans,and how they can be treated. (6p)

Answer 15

RNA viruses, they replicate and mutate fast as they can start protein transcription immediately but they lack proof reading which causes them to be genetically unstable. This means that they can mutate to spread to a new species and they can cause acute infections. DNA viruses have a bigger genome and proof reading. They have proof reading which makes them more genetically stable.

Question 16

Some viruses have unstable genomes, which helps them mutate and evade the immune system. Please explain the difference between influenza antigenic drift and antigenic shift and what importance it has for the spread of the virus? (3p)

Answer 16

Antigenic drift is the accumulation of mutations in the viral genome that codes for viral surface proteins that antibodies recognise. This means that the immune system will be weaker against the new viral strain. Antigenic shift is when two or more viral strains combine to form a new virus creating a mixture of surface proteins.

Question 17

True or false All five hepatitis viruses have viral RNA as genetic material and contain icosahedral capsids as structural surface protein.

Answer 17

-False

Question 18

Hepatitis D is the only hepatitis virus with reverse-transcriptase-like replication pathway of its genome.

Answer 18

-False

Question 19

Among hepatitis viruses the hepatitis B and viruses cause the most severe diseases of the liver.

Answer 19

-True

Question 20

The effective anti-HCV drugs inhibit the HCV non-structural protease and RNA-dependentRNA-polymerase enzymes.

Answer 20

-True

Question 21

he effective anti-HCV drugs inhibit the HCVviralRNA transcription and viral protein trimming.

Answer 21

-True

Question 22

There are some bacterial infections that can cause death within just a few days after symptoms develop if left untreated and cholera is one example. Present what you know about cholera (3 p).

Answer 22

Cholera causes serious diarrhea and it spreads through water and unsanitary conditions. The cholera toxin causes leakage from chloride ion channels which leads to osmosis which leads to diarrhea.

Question 23

which cells in our immune system are the major phagocytic cells?

Answer 23

neutrophils, macrophages, dendritic cells, and B lymphocytes

Question 24

Malaria infections constitute a large burden of disease globally with an estimated 219 million cases and 435 000 deaths in 2017 (WHO World Malaria Report 2018). Prompt and accurate diagnosis of an infection with the malaria parasite is important to be able to give correct medication. Please name the diagnostic methods used in diagnosing a patient with a malaria infection. Also note which diagnostic method that is considered “the gold standard”.

Answer 24

Clinical diagnosis is based on symptoms and physical findings, antigen detection using PCR and blood smear which is considered the golden standard.

Question 25

All viruses depend on the host cell for replication, putting into question whether they should be defined as living or not. Although a large number of viruses are inert components of our genomes, the most well-known viruses are those that are pathogenic. Describe three ways to classify different viruses

Answer 25

If it’s DNA/RNA viruse, if they have an envelope or not an envelope and after their capsid

Question 26

HBV:s genetic material consist of plus-polarized segmented RNA (+ssRNA).

Answer 26

False

Question 27

HBVs genetic material consist of partially double-strained DNA (dsDNA)

Answer 27

True

Question 28

HCV cannot occur as persistent infection

Answer 28

False

Question 29

The immune system can be divided into humoral and cellular mechanisms. What is the main function and importance of the humoral immune defense against influenza virus?

Answer 29

B-cells make antibodies, antibodies (IgG, IgA, IgM) which are special protein that bind to pathogens and then to each other creating clumps that can easier be phagocytes and degraded by other immune cells as well as can’t spread in the body as easily.

Question 30

What does the innate immune system consist of?

Answer 30

Physical barrier(skin)
Mucosal barrier(mucosa in nose can catch viruses before they go down to the lung and then sneeze it out but many mucus membranes also have chemical properties that protect against pathogens).
Stomach acids, low pH and digestive enzymes can break down many pathogens.
The body’s ability to create inflammation, inducing fever etc.
Myeloid cells are part of the innate immune system. The immune cells include neutrophils, macrophages, natural killer cells, mast cells, dendritic cells.

Question 31

What does the adaptive immune system consist of?

Answer 31

Humoral immunity works through antibodies which is a specific form of protein which are made from white blood cells and they travel through the body’s humors so fluids like blood and lymph.
Lymphoid cells are cells that belong to the adaptive immune system. They include B lymphocytes, T helper cells, T regulatory cells and T cytotoxic cells.

Question 32

What does B lymphocytes do?

Answer 32

They travel around the body and have thousands of receptors to recognise pathogens. When they detect pathogens they start to rapidly divide some becoming effector cells which mass produce antibodies and some become memory cells.

Question 33

What T cells are there?

Answer 33

T-cells cause inflammation, activate macrophages, recruit other T-cells, and regulate immune response. T helper cells regulate immune response, cytotoxic T cells induce apoptosis and T memory cells.

Question 34

Describe what you know of malaria

Answer 34

It’s a mosquito carried disease that affect humans and other animals. It leads to fever, tiredness, vomiting and head aches and can in severe cases lead to coma and death.

Question 35

Describe what you know of hepatisis

Answer 35

Hepatisis B and C can lead to chronic infections. It rpelicated in the liver and can enter red blood cells. It’s spread through body fluids, and contaminated food and water.