B1 viral replication

Question 1

What is immunosuppression?

Answer 1

The dampening down, full or partial suppression of the immune response, either naturally or through deliberate intervention.

Question 2

What are some conditions that require immunosuppression?

Answer 2

Autoimmune diseases (RA, SLE, Crohn’s), allergies (asthma, hay fever), organ transplantation, GVHD.

Question 3

. What are the six main ways to suppress the immune system?

Answer 3

Corticosteroids
Cytotoxic drugs
Non-cytotoxic drugs
Trapping activated T cells
Antibodies
Radiation

Question 4

What are corticosteroids?

Answer 4

Steroid hormones that are powerful anti-inflammatory and immunosuppressive agents.

Question 5

Where are corticosteroids naturally produced?

Answer 5

In the adrenal gland.

Question 6

What are the two main classes of corticosteroids?

Answer 6

Glucocorticoids and mineralocorticoids.

Question 7

What is the natural glucocorticoid derivative?

Answer 7

Cortisol.

Question 8

What is prednisone?

Answer 8

A widely used synthetic corticosteroid that is a pro-drug converted into prednisolone in the liver.

Question 9

How do corticosteroids work?

Answer 9

They bind to cytoplasmic steroid receptors, enter the nucleus, and activate transcription of anti-inflammatory genes.

Question 10

What are the effects of corticosteroids?

Answer 10

Reduction in CD4+ T cells, decreased macrophage activation, and inhibition of mast cell degranulation.

Question 11

What are some clinical uses of corticosteroids?

Answer 11

Treatment of autoimmune diseases (RA, SLE), allergies (asthma), inflammatory diseases (Crohn’s), and preventing allograft rejection.

Question 12

What are common side effects of corticosteroids?

Answer 12

Weight gain, osteoporosis, mood swings, cataracts, hypertension, and increased infection risk.

Question 13

What are cytotoxic drugs?

Answer 13

Drugs that kill dividing cells by targeting DNA synthesis.

Question 14

What are examples of cytotoxic drugs?

Answer 14

Cyclophosphamide, methotrexate, mycophenolate mofetil, leflunomide, azathioprine.

Question 15

What are the limitations of cytotoxic drugs?

Answer 15

They are non-specific and affect all rapidly dividing cells, leading to toxicity.

Question 16

What are the main uses of cytotoxic drugs?

Answer 16

Cancer treatment, autoimmune disease management, and preparation for bone marrow transplant.

Question 17

How does cyclophosphamide work?

Answer 17

It alkylates DNA, preventing replication and inducing cell death.

Question 18

What are the side effects of cyclophosphamide?

Answer 18

Bone marrow suppression, alopecia, bladder irritation, sterility, and teratogenic effects.

Question 19

How does methotrexate work?

Answer 19

It inhibits dihydrofolate reductase (DHFR), blocking purine synthesis and T-cell apoptosis.

Question 20

What are the uses of methotrexate?

Answer 20

RA, psoriasis, Crohn’s disease, and some cancers.

Question 21

How does mycophenolate mofetil work?

Answer 21

It inhibits inosine monophosphate dehydrogenase (IMPDH), blocking purine synthesis in T and B cells.

Question 22

What are the uses of mycophenolate mofetil?

Answer 22

Kidney transplant prophylaxis and autoimmune diseases (SLE, nephritis, uveitis).

Question 23

How does leflunomide work?

Answer 23

It inhibits dihydroorotate dehydrogenase (DHODH), blocking pyrimidine synthesis needed by T cells.

Question 24

What are the side effects of leflunomide?

Answer 24

Severe hepatotoxicity (especially with methotrexate) and teratogenic effects.

Question 25

What are non-cytotoxic drugs?

Answer 25

Drugs that do not kill cells but specifically target T-cell signalling.

Question 26

What are examples of non-cytotoxic drugs?

Answer 26

Drugs that do not kill cells but specifically target T-cell signalling.

Question 27

What are examples of non-cytotoxic drugs?

Answer 27

Cyclosporin A, Tacrolimus (FK506), and Sirolimus (Rapamycin).

Question 28

How do cyclosporin A and tacrolimus work?

Answer 28

They bind to intracellular proteins, forming a complex that inhibits calcineurin, blocking IL-2 production and T-cell activation.

Question 29

How does Sirolimus (Rapamycin) work?

Answer 29

It binds to FKBP and inhibits mTOR, blocking cytokine signal transduction and T-cell proliferation.

Question 30

What is the role of S1P in T-cell migration?

Answer 30

Sphingosine 1-phosphate (S1P) helps T cells exit lymph nodes into circulation.

Question 31

How does Fingolimod (FTY720) work?

Answer 31

It binds to S1PR1, trapping T cells in lymph nodes and preventing them from reaching target tissues.

Question 32

What is Fingolimod used for?

Answer 32

Treatment of multiple sclerosis.

Question 33

What are the side effects of Fingolimod?

Answer 33

Headache, colds, nausea, heart rate changes, and macular oedema.

Question 34

What are polyclonal antibodies?

Answer 34

Antibodies derived from animal sera (horse/rabbit) that deplete T cells via complement-mediated lysis.

Question 35

What is a major issue with polyclonal antibodies?

Answer 35

Batch variations and risk of anaphylaxis.

Question 36

What are monoclonal antibodies?

Answer 36

Engineered antibodies targeting specific immune components, reducing unwanted immune responses.

Question 37

What is OKT3 (Muromonab)?

Answer 37

A mouse-derived monoclonal antibody targeting CD3ε on T cells to prevent their activation.

Question 38

What is Basiliximab?

Answer 38

A chimeric anti-CD25 monoclonal antibody that blocks IL-2 induced T-cell proliferation.

Question 39

What is Daclizumab?

Answer 39

A humanised anti-CD25 monoclonal antibody used for kidney transplants and MS.

Question 40

What are the risks of immunosuppression?

Answer 40

Opportunistic infections, increased cancer risk, and other long-term health complications.

Question 41

Why are immunosuppressive drug combinations used?

Answer 41

To enhance effectiveness while reducing individual drug toxicity.

Question 42

What is azathioprine, and how does it work?

Answer 42

A pro-drug converted into 6-mercaptopurine, which inhibits purine synthesis, blocking lymphocyte proliferation.

Question 43

What are the main uses of azathioprine?

Answer 43

Preventing organ transplant rejection, treating autoimmune diseases (RA, Crohn’s, lupus).

Question 44

What are the key side effects of azathioprine?

Answer 44

Bone marrow suppression, nausea, hepatotoxicity, increased infection risk.

Question 45

What is belatacept, and how does it work?

Answer 45

A fusion protein (CTLA-4-Ig) that binds CD80/CD86, preventing T cell co-stimulation via CD28.

Question 46

What is belatacept used for?

Answer 46

Preventing kidney transplant rejection as an alternative to calcineurin inhibitors.

Question 47

What is rituximab, and what does it target?

Answer 47

A monoclonal antibody targeting CD20 on B cells, leading to B cell depletion.

Question 48

What is rituximab used for?

Answer 48

Rheumatoid arthritis, lupus, certain lymphomas, and B cell-mediated autoimmune diseases.

Question 49

What is tocilizumab, and what does it block?

Answer 49

A monoclonal antibody that blocks IL-6 receptors, reducing inflammation.

Question 50

What is tocilizumab used for?

Answer 50

Rheumatoid arthritis, cytokine release syndrome, giant cell arteritis.

Question 51

What is abatacept, and how does it work?

Answer 51

A CTLA-4-Ig fusion protein that inhibits T cell co-stimulation (similar to belatacept but used for autoimmune diseases).

Question 52

What are JAK inhibitors, and how do they work?

Answer 52

Small molecules (e.g., tofacitinib, baricitinib) that inhibit Janus kinases (JAKs), blocking cytokine signalling and T cell activation.

Question 53

What conditions are JAK inhibitors used for?

Answer 53

Rheumatoid arthritis, psoriasis, ulcerative colitis.

Question 54

What is eculizumab, and how does it work?

Answer 54

A monoclonal antibody that inhibits C5, preventing complement activation.

Question 55

What conditions is eculizumab used for?

Answer 55

Paroxysmal nocturnal haemoglobinuria (PNH), atypical haemolytic uremic syndrome (aHUS).

Question 56

What is alemtuzumab, and what does it target?

Answer 56

A monoclonal antibody targeting CD52 on T and B cells, leading to profound lymphocyte depletion.

Question 57

What is alemtuzumab used for?

Answer 57

Multiple sclerosis (MS), chronic lymphocytic leukaemia (CLL).

Question 58

What are common side effects of monoclonal antibodies?

Answer 58

Cytokine release syndrome, infusion reactions, increased infection risk, reactivation of latent infections (e.g., TB, hepatitis B).

Question 59

What is the difference between polyclonal and monoclonal antibodies?

Answer 59

Polyclonal antibodies: Derived from multiple B cell clones, broader target range. → Monoclonal antibodies: Derived from a single B cell clone, highly specific.

Question 60

Why are calcineurin inhibitors (cyclosporin/tacrolimus) nephrotoxic?

Answer 60

They reduce renal blood flow and increase vasoconstriction, leading to kidney damage over time.

Question 61

What is sirolimus (rapamycin) often used with in transplant therapy?

Answer 61

Used with cyclosporin/tacrolimus but at lower doses to reduce nephrotoxicity.

Question 62

What is the benefit of using mycophenolate mofetil over azathioprine?

Answer 62

More selective for T and B cells, fewer side effects, less bone marrow suppression.