Immunology SBA

Question 1

What leads to DiGeorge syndrome

Answer 1

Infants with this syndrome lack a thymus and so have no circulating T-cells. They have a normal number of B-cells but cannot make an effective antibody response against most antigens. Caused by deletion of part of chromosome 22. Diagnosed- fluorescent in stiu hybridisation. Symptoms also include palatal abnormalities and learning difficulties -> SCID

Question 2

What leads to Kaposi’s sarcoma

Answer 2

HHV8 - AIDS predisposes you for this condition

Question 3

What leads to SCID - severe combined immunodeficiency

Answer 3

mutations in genes for cytokine signalling molecules e.g. IL-2 receptor and Jak3 (a protein kinase)

Other causes of SCID include RAG 1/2 and adenosine deaminase (ADA) mutations

Defect in T-cells

Question 4

Definitive diagnosis for AIDS?

Answer 4

Reduction in CD4 T cells (below 200 microL-1)

Question 5

Cell surface molecule that recognises LPS?

Answer 5

TLR4

Question 6

Rearrangement after primary immune response

Answer 6

• somatic recombination in B
• cells driven by VDJ recombinase complex within heavy chain.
• V&;J with light chain (no D genes).

Also note affinity maturation – where antibody affinity is higher in secondary challenge.

Question 7

What is thymic atrophy?

Answer 7

reduction in size of thymus, and consequent reduction in T cell production. Deficiency leads to SCID

Question 8

What is ADA?

Answer 8

adenine deaminase - breaks down a key enzyme important for lymphocyte production. Deficiency leads to SCID. SCID is a defect in T-cells and has mutations.

caused by mutations in genes for cytokine signalling molecules e.g. IL-2
• RAG 1/2 and adenosine deaminase (ADA) mutations

Question 9

Which Ig component is most polymorphic?

Answer 9

the variable region within the heavy chain as it contains VDJ genes. Note: light chain only contains VJ (no D genes)

Question 10

What Ig component recognises LPS?

Answer 10

toll like receptors (mainly TLR-4).

NOD1;2 – peptidoglycan recognition.

RIG – viruses

Question 11

What haplotype out of the list is most associated with autoimmune disorders

Answer 11

HLA

Question 12

What causes granulation tissue?

Answer 12

macrophages surrounded by T cells - mycobacterial

Question 13

type of hypersensitivity for SLE, systemic anaphylaxis and serum sickness

Answer 13

Systemic anaphylaxis – type I hypersensitivity

Serum sickness – type III hypersensitivity

Question 14

Whitelock

Answer 14

Mg

Question 15

Treg

Answer 15

suppresses other T-cells. Cytokine 3rd signal: TGF-B. Cytokines produced: TGF-B and IL-10

Question 16

Preventing viral replication

Answer 16

acyclovir

Question 17

Organ transplant

Answer 17

Alloreactive CD4 respond to HLA II

alloreactive CD8 respond to HLA I

Question 18

Immunology molecules/receptors and their function - HLA, Ig, KIR

Answer 18

KIR are expressed on NK cells

Question 19

HLA

Answer 19

particular variant of HLA gene more likely to get an autoimmune disease

Question 20

GVHD

Answer 20

Allogenic-HLA matched

medical complication following the receipt of transplanted tissue from a genetically different person. GvHD is commonly associated with stem cell transplants such as those that occur with bone marrow transplants. GvHD also applies to other forms of transplanted tissues such as solid organ transplants. APC activation leads to target tissue destruction.

Question 21

Graft tolerance immunosuppression

Answer 21

-corticosteroids; cyclosporin (immunosuppression)

Question 22

Cyclosporin

Answer 22

> gingival overgrowth

Question 23

What happens in XLA?

Answer 23

reduction in B cells

Question 24

Which is the most polymorphic gene?

Answer 24

notes say:
HLA alleles – most polymorphic variants in the population

Cheat sheet says:
gene encoding T cell receptor

Question 25

Encodes cell surface molecule that recognises LPS?

Answer 25

TLR variable region gene

Question 26

Is most highly polymorphic?

Answer 26

HLA I think but could. be TCR variable-region gene as HLA is the answer to the haplotypes qs

Question 27

Has haplotypes associated with autoimmune diseases?

Answer 27

HLA

Question 28

Tregs

Answer 28

suppression of T cell response e

IL10 and TGFb

Question 29

Th2

Answer 29

mast cell and B cell activation

Question 30

Naïve t cells?

Answer 30

not encountered antigen yet

senses antigen in primary immune response

Question 31

Th1?

Answer 31

promotes formation of granulomas

Question 32

CD8?

Answer 32

killing virally infected cells

Question 33

T-follicular helper cell?

Answer 33

class switching

Question 34

consequence of X-linked agammaglobulinemia?

Answer 34

low circulating B cells

Question 35

evidence of AIDS?

Answer 35

circulating antibodies in HIV

Question 36

leads to SCID?

Answer 36

ADA deficiency

Question 37

Evidence of DiGeorge?

Answer 37

thymic atrophy

Question 38

Associated with HHV8?

Answer 38

Kaposi’s sarcoma

Question 39

Consequence of complement mediated chemotaxis?

Answer 39

Neutrophil act

Question 40

Percentage for extreme dental anxiety?

Answer 40

12% - extreme, 36% moderate

Question 41

What leads to DiGeorge syndrome?

Answer 41

Infants with this syndrome lack a thymus and so have no circulating T-cells. They have a normal number of B-cells but cannot make an effective antibody response against most antigens. Caused by deletion of part of chromosome 22.

Diagnosed- fluorescent in stiu hybridisation.

Symptoms also include palatal abnormalities and learning difficulties -> SCID

Question 42

What leads to Kaposi’s sarcoma?

Answer 42

HHV8 - AIDS predisposes you for this condition

Question 43

What leads to SCID - severe combined immunodeficiency?

Answer 43

Mutation in RAG1/2 & ADA & IL-2 receptor. Defect in T-cells

Question 44

Definitive diagnosis for AIDS?

Answer 44

Reduction in CD4 T cells (below 200 microL-1)