Essay questions

Question 1

What are t-reg cells 7

Answer 1

.Type of T cell to prevent disease
.uses t-factor foxp3 for development
.Produced in thymus
.2 types: nat t regs (immune tolerance) induced (control infl)
. stops growth of self reactive t cells
. donme by antiinflammatory enzymes
. role: controls IS response, dif between harmful/less cells, prevents AI diseases

Question 2

Phagocytosis 4

Answer 2

.Ingests and kills pathogens
.Uses N+M
.PAMP binds to TLR on phagocyte
. steps

Question 3

Pattern recognition receptors 5

Answer 3

.Detects pathogens

. Dif between self/non

.rec by binding to pamps

.Found on N+M DC MC

. Toll like cell surface LPS; Rig-1 Cytoplasm (viral RNA) ; C-type Cell surface carbs

Question 4

Types of antibody/isotopes

Answer 4

.5 types of Ig MADGE,BMIBP
. Heavy and light chain
. held by disuplhide bond
. cell sends receptor which best for fit
.FAB binds to antigen

Question 5

Exogeneous pathway 5

Answer 5

. EC pathway, presents A to IS
.Steps:APC gains A by P/E surrounded by phagosome broken by lysosome
Put onto MHCll on surface
.cd4 binds to rec

.(cd28-TC + B7-APC)
CD$ prod cytokines

Question 6

Endogeneous pathway

Answer 6

IC,Presents antigens on surface with MHCl
G: responds 2 IC Pathogens, attack IC, act cd8
steps:Antigen broken by proteasome, moves to ER with TAP, binds to MHCl, move 2 GA, antigen to IS, cytotoxic cd8 bind + rec, releases enzymes 4 apoptosis

Question 7

Innate response

Answer 7

1st line, fast NS no memory,
skin, muc MB,Acid, lysozyme tears+Sal
M+N, NK, DC present
PRR binds 2 PAMP on PAth
Trigs IMFL response, enhanced by CS

release enzymes 4 opsonisation, inc ror, cytokines + interferons attract NK

Question 8

Inflammatory mediators during degranulation

Answer 8

Role: Inc eff of IS+CS
Histamine: Inc perm, inc BF vasodilation
Cytokines: Brings/attracts IC to INFl site, trigs IR
Proteases: Breaks PAth cell wall, allows IC to enter
Serotonin sim to Hist

Question 9

The different immune responses of innate and adaptive 2

Answer 9

I: Fast,NS, uses Pamps + trr, uses M+N, DC and NK, uses complement, no mem, helps to activate adaptive system

A: 1st slow 2nd fast, S, B+T 8k,4h,releases cytokines

Question 10

Complement pathway 4

Answer 10

Uses a series of proteins to eliminate pathogens,
1: igG binds to A on AS, c1 binds to c2+4=c4b2a, this tags proteins

LP: Binding lectin, binds to P on S, act MASPS, splits c2+4=c3…. prods c3b=coats pathogen

AP: no pathogen need… c3=c3bBb= amplified response….

opsonisation, MAC= pierces

Question 11

Immunology response during hypersensitivity 4

Answer 11

1. Trig by allergens stps: become sensitive IgE, rec by MC, response sensitised, degranulation
2. cytotoxic: cell dest due 2 AB, igG+M prod, AB bind to A, phagocytosis by M+N e.g goodpasture
3. Antigens deposited on tissue, IgG+M bind to antigen- deposited, activates CS acts inflamms c3a+5 attacks, APC, T cell release enzyme e.g arthiritis
4. APC presents A to cd4, th1 release cytokines, cd8 attack APC, t cell release enzyme, e.g tb

Question 12

Role of MHC1 in antigen presenting + t cell functions

Answer 12

Presents endogenous antigens, In ER peptides bind to mhc1, moves to surface through GA, 2b displayed
In t cell: Rec cd8, binds to tcr acts cd8 prods cytotoxic t lmyph = destroy abnormal cells

Question 13

How immunoglobulin contributes to the removal of infectious microbes 5

Answer 13

Produced by b cells , marks for destruction

1. neutralisation - AB binds to P, stops spread
2. opsonisation - Coats antigen for dest by M+N
3. Complement acti - BInding of AB act CP = forms MAC - cell lysis
4. Antibody dependent cell mediated cytotoxicity - AB binds to A, NK rec = releases cytotoxic material = apoptosis