Intracellular Pathogens

Question 1

What are the adaptive immune defences

Answer 1

T cells, B cells, antibodies

Question 2

Symptoms of Tuberculosis

Answer 2

Coughing up blood, weight loss, night sweats, caseating granulomas, necrosis, cavitation

Question 3

Percentage of population in which tb causes infection

Answer 3

30%

Question 4

What are the types of cells which Mtb infects

Answer 4

Macrophages, dendritic cells and monocytes

Question 5

Methods by which phagocytes kill Mtb after it enters the cell via phagocytosis?

Answer 5

Matures to phagolysosome, nutrient deprivation, membrane permeation, hydrolases, reactive oxygen and nitrogen species and acidification

Question 6

How does Mtb evade innate responses?

Answer 6

Prevents phagosome maturation by preventing fusion with endosome

Question 7

How do APCs detect pathogenic invasion?

Answer 7

Detect PAMPs (pathogen associated molecular patterns)

Question 8

What are the results of macrophage activation during Mtb infection?

Answer 8

Increase no of MHC molecules, TNF, IFNg receptors.

Release TNF, il-1, il-12 and il-18

Question 9

What do NK cells release to further activate macrophages in Mtb infection?

Answer 9

IFNg

Question 10

How is the adaptive immune response activated when infected with Mtb?

Answer 10

Dendritic cells migrate to lymph nodes and activate TH1 CD4+ cells which in turn activate CD8+ T cells to launch cytotoxic attack

Question 11

What is the last resort if all other attempts to prevent infection from Mtb fail?

Answer 11

Form a granuloma around the infected cells to prevent spreading

Question 12

What are the 3 subfamilies of herpesvirus

Answer 12

Alpha, beta, gamma

Question 13

What family of herpesvirus does EBV belong to?

Answer 13

Gamma

Question 14

Which programme does EBV enter when it infects a naive B cell and what are the results?

Answer 14

Growth programme which activates the B cell

Question 15

Which programme does EBV enter when it infects a germinal cell centre B cell and what are the results?

Answer 15

Default programme causes activated B cell to differentiate to memory cell

Question 16

Which programme does EBV enter when it infects a blood memory B cell and what are the results?

Answer 16

Latency programme causing lifetime persistence

Question 17

Which programme does EBV enter when it infects a dividing blood memory B cell and what are the results?

Answer 17

EBNA-1 only programme causing viral DNA in latency programme cells to divide

Question 18

Which programme does EBV enter when it infects a plasma B cell and what are the results?

Answer 18

Lytic programme causing virus to replicate in cell

Question 19

What is the purpose of NK cells secreting IFNg upon infection with EBV?

Answer 19

Activate T cells

Question 20

Which interleukin is secreted by dendritic cells for optimal IFNg responses?

Answer 20

IL-12

Question 21

Where is the latency reservoir generated?

Answer 21

In lymphoblastoid cell line like cells (LCL cells)

Question 22

Name 3 human carcinomas which are related to EBV infection

Answer 22

Burkitts lymphoma
Hodgkin’s lymphoma
Nasopharyngeal carcinoma

Question 23

What are the innate defences

Answer 23

Skin, mucous, membranes, NK cells, phagocytosis, complement and interferon