Lecture 26 - Immunity and Infection

Question 1

Factors of immunity and infection - microbial?

Answer 1

type, virulence, amount, route of entry

Question 2

Factors of immunity and infection - host?

Answer 2

integrity of innate barriers, adaptive immune competence, HLA, Ig and TCR genes, previous exposure, other infections

Question 3

Pathogens and antigens - viruses?

Answer 3

capsid antigens or HLA I presented metabolic or internal structured components

Question 4

Pathogens and antigens - bacteria and fungi?

Answer 4

extracellular (aureus) or intracellular (m. tuberculosis), structural components and metabolic components and toxins

Question 5

Cytotoxic T cells vs antibodies?

Answer 5

rather than antigens outside cells of body (toxins, bacteria, viruses), is effective against intracellular protein antigens (viral cytoplasmic peptides, tumour cells, transplanted organs)

Question 6

Complement cascade?

Answer 6

DRAW IT MOTHER FUCKER

Question 7

Immunity to bacteria - antibodies and complement?

Answer 7

prevent adherence or reduce mobility, enhance bacterial destruction (complement), enhance phagocytosis (opsonisation)

Question 8

Bacterial tactics to avoid antibodies?q

Answer 8

opsonisation resistant capsules e.g. Haemophilus influenzae, intracellular growth e.g. M tuberculosis

Question 9

Mucosal immunity?

Answer 9

IgA in mucosa first blockade, then IgE presenting mast cells detect antigen and release vasoactive and chemotactic factors, causing blood vessels to release IgG, complement, neutrophils and eosinophils

Question 10

Receptors of K/NK cells?

Answer 10

Fc(gamma) receptor for ADCC, killer-activating and killer-inhibitory receptor for natural killing activity

Question 11

NK cell physiology?

Answer 11

binding of killer-inhibitory receptro to HLA I gives no action, lack of binding leads to cell killing, enhanced by IL-2 and IFN-(gamma), important in early viral infection and cancer

Question 12

Acute viral infection?

Answer 12

virus amount on the rise, interferon from infected cells rise accordingly, Nk activity follows suit, delay then cytotoxic T cells have been formed and rise, antibodies rise last and are to prevent re-infection rather than fight illness

Question 13

Pro-inflammatory cytokines?

Answer 13

early, induce acute phase proteins, fever and behavioural changes, tissue repair (bone reabsorption, fibroblast proliferation, collagenase synthesis, leukocyte adhesion), T and B cell activation

Question 14

Chemokines?

Answer 14

aid chemotaxis, direct effector cell traffic

Question 15

Interferons?

Answer 15

induce transient antiviral state, activate NK cel activity, upregulate MHC expression (therefore improving cytotoxic T cell killing)