Mid Semester Exam Study Flashcards Preview

CHI305 - Immunology > Mid Semester Exam Study > Flashcards

Flashcards in Mid Semester Exam Study Deck (42)
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0
Q

Escherichia?

A

A prokaryote (cell that lacks a membrane bound nucleus)

1
Q

Amoeba?

A

A eukaryote ( a cell that contains a nucleus)

2
Q

Vision?

A

Mature virus comprising all parts

3
Q

Viroid?

A

Infectious circular RNA plant pathogen

4
Q

Prion?

A

Infectious protein

5
Q

Viral nucleic acid

A
  • does not contain genes needed for synthesis of new virus
  • does not contain genes needed for energy generation
  • only RNA or DNA not both (single stranded or double stranded)
6
Q

Viral capsid

A
  • protein coat covering virus
  • symmetrical
  • antigenic properties
  • protects nucleic acid from enzymes
  • assists in attachment and entry
7
Q

Viral envelope

A

-lipid bilayer made from membrane of host cell

8
Q

A virus lacking an envelope is considered to be?

A

A naked virus

9
Q

Naked viruses are considered more resistant to the environment because?

A
  • the envelope is damaged easily
10
Q

Inactivation of a virus outside of a host cell

A
  • heat of 60 degrees for 30 minutes
  • envelope can be destroyed by detergent
  • chemically harder to kill than bacteria
  • some can last days at 4 degrees
  • some are stable in salt solution
  • generally stable at pH 5-9
11
Q

Virus classification

A
  • classified by:
  • nucleic acid
  • DNA virus
  • RNA virus
12
Q

A virus genome is either?

A
  • DNA or RNA
13
Q

What is a genome?

A
  • a virus genome is RNA or DNA never both
  • it is encoded in its nucleic acid
  • may be single stranded, double stranded, circular or linear, positive sense (mRNA) or negative sense
14
Q

Structure of a virus

A
  • nucleic acid genome
  • enclosed in protein coat or capsid
  • can be further enclosed in envelope
  • non- living
  • smallest infectious agent
15
Q

3 types of cell cultures for growing a virus?

A
  • primary cell culture
  • secondary cell culture
  • immortal cell culture
16
Q

What is involved in a primary cell culture?

A
  • embryonic tissue removed from embryo using sterile techniques
  • tissue must then be broken down to individual cells physically (chopped) and chemically (trypsin and/or detergent)
  • cells are then placed into an appropriate liquid medium
17
Q

What is involved in a secondary cell culture?

A
  • cells are derived by re-trypsination and re-culture in fresh medium of successfully grown primary cells
18
Q

What is involved in an immortal cell culture?

A
  • using originate from tumour and are therefore cancer cells, such as CHO, Hela and vero cells
19
Q

Making vaccines- advantages and disadvantages

A
  • traditional method for influenza virus vaccine production was to use chicken eggs
  • pros: inexpensive, well established
  • cons: need millions of eggs, production time is 6 months
20
Q

Characteristics of a Prion

A
  • abnormal proteins
  • transmitted or inherited
  • slow onset (10-30 years)
  • no vaccine or treatment available
  • causes slow reduced function of brain
  • no immunological activity
  • in mammalian species
  • survives in pastures
  • causative agent of spongiform encephalopathies
21
Q

Prions are resistant to what?

A
  • chemical disinfectants
  • heats (360 degrees, 1 hour)
  • DNAse and RNAse
  • UV lighting
  • ionising radiation
  • high temp autoclaving
  • burying for 3 years
  • formaldehyde fixation
22
Q

Polymerase chain reaction objective?

A
  • to amplify unknown DNA, generating millions of copies of a single DNA piece of a DNA sequence
23
Q

What occurs in polymerase chain reaction?

A
  • primer binds to unknown DNA
  • amplify DNA
  • compared with known sequences
24
Q

Steps of polymerase chain reaction

A
  1. Denaturation
    - 1 minute at 94 degrees
  2. Annealing
    - 45 seconds at 54 degrees
  3. Extension
    - 2 minutes at 72 degrees
25
Q

What is innate immunity?

A
  • NOT SPECIFIC for the pathogen
  • combats all pathogens no matter their type (bacteria, viruses, pathogens)
  • innate defence
26
Q

What is involved in innate defence?

A
  • surface barriers
  • phagocytic cells
  • natural killer cells
  • inflammation
  • anti microbial proteins
  • fever
27
Q

What is an antibody?

A
  • protein
  • made by B cells
  • is a receptor of B cells
  • binds to antigens
  • product of adaptive immunity
  • end product of humeral immunity
28
Q

What are Kinins?

A
  • act on smooth muscle (causes contractions)
  • block nervous impulses (causes muscle relaxation)
  • causes contractions of vascular endothelial cells (bradykinin)
  • releases endothelial cell adhesion molecules
  • responsible for pain and itching with inflammation
  • inactivated by proteases
29
Q

What are cytokines?

A
  • soluble mediators of the immune system
  • chemical drivers of the immune system
  • mediate signals between leukocytes (interleukin 1-23)
30
Q

What is acquired immunity?

A
  • the immunity that our body gains over time
  • the body generates special chemicals, also known as antibodies that neutralise the harmful toxins produced by the pathogen
  • each specific such of pathogen needs a custom chemical to neutralise it
31
Q

What are the major cell types of acquired immunity?

A
  • T lymphocytes

- B lymphocytes

32
Q

4 branches of acquired immunity?

A
  • specificity
  • diversity
  • discrimination between self and non- self
  • memory
33
Q

Immunological memory

A
  • the ability of lymphocytes to respond faster and more strongly to a re-encounter of the same antigen
34
Q

Variable region of an antibody

A
  • V regions are the variable part of an antibody

- C regions are the constant part of an antibody

35
Q

The immunoglobulin Ig structure?

A
  • Y-shapes molecule that consists of four polypeptide chains, two identical heavy chains and two identical light chains, connected by disulfide bonds
36
Q

What is the crystallisable region of an antibody?

A
  • also known as the Fc region is the tail region of the antibody that interacts with cell surface receptors called Fc receptors
  • this property allows antibodies to activate the immune system
37
Q

What is CD3?

A
  • cluster of differentiation 3
  • protein complex and is composed of 4 distinct chains
  • these chains associate with T-cell receptors to generate an activation signal in T lymphocytes
38
Q

What are the two types of T cells?

A
  • CD4 T cells and CD8 T cells
  • in healthy individuals ratio in circulation is 2CD4: 1CD8
  • CD4 binds to cells expressing MHC class 2 molecules
  • CD4 cells: dendritic cells, macrophages, B cells and thymus epithelial cells
  • CD8 cells bind to cells expressing MHC class 1 molecules ( all nucleated cells)
39
Q

What are the co-receptors on T cells and what do they bind to?

A
  • activation of T cells require co- receptors
  • co- receptors are the CD4 and CD8 molecule which are provided by the T cell
  • CD4 T cells are helper T cells and bind to MHC class 2 ( exogenous antigens)
  • CD8 T cells are cytotoxic and bind to MHC class 1 ( endogenous antigens)
40
Q

What cells have MCH1, 2, CD3, CD4, CD8?

A
  • MHC1: viral replication cells, bacterial cells, parasites, tumours
  • MHC2: dendritic cells, macrophages, B cells, thymus epithelial cells
  • CD4: T helper cells
  • CD8: cytotoxic cells (killer cells)
  • CD3: expressed on surface of mature T cells
41
Q

Primary and secondary immune response?

A
  • primary response: first encounter with virus or bacteria. Naive T cells and B cells are activated and form memory cells
  • secondary response: re-encounter of the same virus/ bacteria which you now have memory T cells and B cells causing a rapid response