IL5 Immunity to Bacterial Infection

Question 1

Extracellular bacteria involves ______-mediated immunity.
Intracellular bacteria involves ______-mediated immunity.

Answer 1

Antibody.
Cell (T-cell)

Question 2

Basic responses of innate immunity

Answer 2

Complement binds and kills.
Neutrophils phagocytose and kill.
Macrophages will phagocytose and kill.
DC will take up antigens for presentation.

Question 3

Phagocytes

Answer 3

Neutrophils, monocytes, dendritic cells, macrophages

Question 4

Development of macrophages

Answer 4

Express PRRs to detect microbe. Engagement initiations phagocytic receptors and cytoskeletal rearrangements. Internalisation of microbe, phagosome/lysosome fusion to form the phagolysosome.

Question 5

Lysosome enzymes

Answer 5

Proteolytic enzymes to degrade microbial proteins into short peptides

Question 6

Class II MHC containing vesicles

Answer 6

Present in the cytoplasm of AP cells, and fuse with phagolysosomes to be transported to the cell surface.

Question 7

DC presentation of microbial derived peptides

Answer 7

Presents to CD4+ cells in the lymph node.

Question 8

Antigen processing consequences

Answer 8

Presence of microbial proteins in the cytoplasm of infected cells. All proteins are cleaved, MHC-I molecules are loosely attached to the transporter associated antigen presentation.

Question 9

TAP function

Answer 9

Drives transport of cytoplasmic proteins in to the E.R. lumen where they’d an associate with MHC-I molecules.

Question 10

Processof antigen presentation to T cells

Answer 10

CD4 binds to class II MHC on dendritic cells. Co-stimulation through B7-CD28 interactions are also required for T cell activation. Results in the interleukin-2 and interleukin-2 receptor genes being transcribed.

Question 11

Clonal expansion

Answer 11

T cells proliferate upon presentation of antigens and activation of IL-2/IL-2Rs.
Some will be effector cells, other long-lived memory cells.

Question 12

Naive lymphocyte circulation

Answer 12

Circulate between secondary and tertiary lymphoid tissues.

Question 13

CD8+ T cell activation

Answer 13

In the lymph node, antigens are carried to the B cell area and trapped on the surface of complement receptors. Receptor mediated cytosis or diffusion. Engaged B cells move to the boundary and Stimulated B cells move about in the T cell until they make contact with an antigen specific T cell.

Question 14

B cell activation

Answer 14

Co-stimulationn via cell surface ligand-receptor pairs and additional help via cytokines. B cell then proliferates to express the same antigen-specific antibody.

Question 15

T helper cells and specific cytokines

Answer 15

Dictate which isotope class of antibody the plasma cell will secrete

Question 16

Intracellular bacterial infection

Answer 16

Some bacteria avoid humoral immunity by hiding inside the cells; upon phagocytosis they can escape the phagosome.

Question 17

How are intracellular pathogens detected

Answer 17

Class MHC I is constantly presenting new protein antigens in the cytoplasm, including escaped bacterial and viral antigens. CD8 T cells can recognise this cell!

Question 18

Tuberculosis overview

Answer 18

LIves inside the phagosome, prevents phagosome-lysosome fusion to resist killing.
IFN-γ from T cells helps but IFN activation is shut down.

Question 19

Th1 cell mediated immunity

Question 20

Incipient tubercle and caseous necrosis

Question 21

Granuloma formation