Viruses and the Immune System

Question 1

What are the different types of genetic material found in viruses?

Answer 1

DNA or RNA, single or double stranded

This distinction is crucial in understanding how viruses replicate and interact with host cells.

Question 2

What surrounds the genetic material in a virus?

Answer 2

A protein coat called the capsid

The capsid protects the viral genetic material and aids in the infection of host cells.

Question 3

What do we call the membrane that sometimes surrounds the capsid?

Answer 3

Viral envelope

The viral envelope is derived from the host cell membrane and contains viral glycoproteins.

Question 4

What do we call the proteins in the ‘cell membrane’ of a virus?

Answer 4

Glycoproteins

Glycoproteins play a key role in the virus’s ability to attach to and enter host cells.

Question 5

What is the infamous envelope protein in the Covid virus?

Answer 5

The spike protein (S protein)

The spike protein facilitates entry into human cells and is a target for vaccines.

Question 6

Distinguish between lytic and lysogenic cycles in viruses.

Answer 6

Lytic destroys host cell, lysogenic integrates viral DNA

The lytic cycle leads to immediate viral replication and cell death, while the lysogenic cycle allows the virus to remain dormant within the host.

Question 7

Does HIV have both cycles? What is the significance?

Answer 7

Yes, lysogenic allows dormancy and harder treatment

This dormancy complicates treatment strategies as the virus can evade the immune response.

Question 8

What do we call a global epidemic?

Answer 8

Pandemic

A pandemic affects a large number of people across multiple countries or continents.

Question 9

Who is known as the father of epidemiology?

Answer 9

John Snow

He is famous for his work on cholera and the importance of clean water.

Question 10

What disease did John Snow study the spread of? What was the source of the disease?

Answer 10

Cholera; contaminated water pump

His investigation led to significant public health changes regarding water sanitation.

Question 11

Why were epidemics rare for 95% of human history?

Answer 11

Low population density and limited travel

These factors limited the spread of infectious diseases.

Question 12

What does R naught tell us about epidemics? What virus has a high R naught?

Answer 12

How contagious a disease is; measles has a high R₀

R naught indicates the average number of people one infected person will infect.

Question 13

What virus are we close to eliminating? What do epidemiologists do when there is an outbreak?

Answer 13

Polio; trace and contain the outbreak

Active surveillance and containment strategies are essential in outbreak management.

Question 14

What virus have we eradicated from the human population?

Answer 14

Smallpox

Smallpox is the only human disease to be eradicated through vaccination.

Question 15

What is the term we use to describe the pathogens that we get from animals?

Answer 15

Zoonotic

Zoonotic diseases can be transmitted from animals to humans, often through direct contact or environmental factors.

Question 16

What animals does influenza jump from to infect humans?

Answer 16

Pigs and birds

These animals serve as reservoirs for various strains of the influenza virus.

Question 17

What animals harbor a lot of different viruses?

Answer 17

Bats

Bats are known to carry a wide variety of viruses, including coronaviruses.

Question 18

Why is our skin good at protecting us from pathogens?

Answer 18

It’s a physical barrier, dry, acidic, and tightly packed

These properties help prevent pathogen entry and inhibit growth.

Question 19

What coating protects our epithelial cells (respiratory/digestive) from pathogens?

Answer 19

Mucus

Mucus traps pathogens and particles, facilitating their removal from the body.

Question 20

What are the first cells to encounter pathogens in our bloodstream?

Answer 20

Macrophages

Macrophages play a critical role in the innate immune response.

Question 21

How do macrophages ingest cells?

Answer 21

Phagocytosis

This process involves engulfing and digesting pathogens.

Question 22

How do neutrophils kill pathogens?

Answer 22

By releasing neutrophil extracellular traps (NETs)

NETs trap and kill pathogens extracellularly, contributing to the immune response.

Question 23

What are the 5 markers of inflammation?

Answer 23

Redness, heat, swelling, pain, loss of function

These markers indicate the body’s response to injury or infection.

Question 24

How does the release of cytokines help direct the immune response?

Answer 24

They signal and recruit immune cells to the site

Cytokines are key mediators in coordinating the immune response.

Question 25

What cell does the Macrophage (and/or dendritic cell) activate by showing the antigen?

Answer 25

Helper T cell ## Footnote This activation is crucial for initiating adaptive immunity.

Question 26

What does the Helper-T cell do?

Answer 26

Activates B cells and cytotoxic T cells ## Footnote Helper T cells are essential for orchestrating the adaptive immune response.

Question 27

What virus infects Helper T cells, making the person 'immunodeficient'?

Answer 27

HIV ## Footnote HIV specifically targets and destroys Helper T cells, compromising the immune system.

Question 28

What cell makes antibodies?

Answer 28

B cells ## Footnote B cells are key components of the adaptive immune response, producing antibodies specific to pathogens.

Question 29

What type of T cell can kill cells?

Answer 29

Cytotoxic T cell ## Footnote Cytotoxic T cells are essential for eliminating infected or cancerous cells.

Question 30

What type of T cell calls off the attack?

Answer 30

Regulatory T cell ## Footnote Regulatory T cells help maintain immune tolerance and prevent overactive immune responses.

Question 31

What type of T and B cell will circulate in the blood in case of a second infection?

Answer 31

Memory cells ## Footnote Memory cells provide long-term immunity by quickly responding to previously encountered pathogens.

Question 32

What is considered the perfect vaccine?

Answer 32

Live attenuated vaccine ## Footnote Live attenuated vaccines elicit strong and long-lasting immune responses.

Question 33

What is the second best type of vaccine?

Answer 33

Inactivated or killed vaccine ## Footnote These vaccines are made from viruses that have been killed or inactivated, providing immunity without the risk of disease.

Question 34

Why can’t we make a permanent vaccine for HIV or Influenza virus?

Answer 34

High mutation rates and antigenic variation ## Footnote These factors allow the viruses to evade the immune response and complicate vaccine development.

Question 35

Who came up with the process of the first vaccine? What was the vaccine? What did it successfully prevent?

Answer 35

Edward Jenner; cowpox vaccine; prevented smallpox ## Footnote Jenner's work laid the foundation for modern immunology.

Question 36

Who coined the term 'Vaccine'? Why are vaccines called vaccines?

Answer 36

Louis Pasteur; from Latin 'vacca' for cow ## Footnote The term reflects the origins of vaccination in the use of cowpox to prevent smallpox.

Question 37

What is anti-snake venom?

Answer 37

Antibodies that neutralize snake venom ## Footnote Anti-snake venom is used in medical treatments for snake bites.

Question 38

Who normally produces anti-snake venom?

Answer 38

Horses or other large mammals ## Footnote These animals are immunized with small amounts of venom to produce antibodies.

Question 39

What type of antibodies are used to fight cancer?

Answer 39

Monoclonal antibodies ## Footnote Monoclonal antibodies are designed to target specific cancer cells, enhancing treatment efficacy.