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Basic Immunology- Module 1 > Immune responses to viruses > Flashcards

Flashcards in Immune responses to viruses Deck (39)
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1

What is a virus?

an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy and is able to multiple only within the living cells of a host

2

What is the programme viruses have to self-replication and multiplication?

gene expression; genome replication; virus assmebl; virus release and transmission

3

how are viruses classified?

Baltimore classificaation: type of genoma and method of replication

4

Give examples of dsDNA viruses?

herpes; poxvirus; adenovirus; papillomavirus

5

Give examples of ssDNA viruses?

adeno-associated virus

6

Give examples of dsRNA viruses?

reovirus

7

Give examples of negative ssRNA viruses?

influenza

8

Give examples of positive ssRNA viruses?

poliovirus; hep A and C

9

Give exaample of reverse RNA virus?

HIV

10

Give an example of a reverse DNA virus?

hep b

11

Give an example of a cytopathic virus

hep B

12

Give an example of a non-cytopathic virus?

rhinovirus

13

What is involved in immmunity against chronic viruses?

T cells

14

what is involved in immunity against acute viruses?

neutralising antibodies

15

What aer the features of barrier protection against infection in the skin?

epithelial cells joined by tight junctions; longitudinal flow of air/fluid; fatty acids; antibacterial peptides; normal flora

16

What are the type III interferons?

IFN delta 1,2,3

17

What are the functions of type I and type III IFNs?

induce antiviral repsonses and limit viral replication

18

Which cells are IFN receptors found on?

all nucleated cells

19

What do NK cells secrete to lyse cells?

perforin and granzyme B

20

What activates invariant and unconventional T cells?

lipids; microbiota metabolites or cytokines

21

What are the types of invariant and unconventional T cells?

NKT; MAIT and yd T cells

22

How is infection related to viral load and T cell response?

infection occurs at the same time as T cell reponse not at the peak of the viral load

23

How are antibodies invovled in the removal of viruses?

coat infected cell which leads to ADCC by NK cells; activate complement; opsonise for phagocytosis

24

Which cells are specialised for production of type I IFns?

plasmacytoid DCs

25

What is the function of Th1 cells in viral responses?

provide help for opsonising and complement fixing virus specific abs that block entry into uninfected cells and activate complemetn to destroy enveloped viruses

26

Why do RNA viruses have a higher rate of replication than DNA viruses?

have to replicate their genoma using RNA polymerase which lacks the proofreading ability of DNA polymerase

27

What is the benefit of RNA polymerase for RNA viruses?

high rate of mutations allows them to change the antigenic epitopes recognised by the adaptive immune system

28

Aside from RNA polymerase, what other mutation mechanism do RNA viruses have?

segmented genomes which they can rearrange during viral replication

29

What are the major viral surface glycoproteins?

haemagluttinin and neuramidase

30

What is antigenic drift?

point mutations which change the epitopes on the viral surface glycoproteins recognised by adaptive immune system