Basic Immunology - Leukocytes & antibodies (PAIS)

Question 1

What are the two types of leukocytes?

Answer 1

Innate leukocytes and acquired leukocytes (lymphocytes)

Question 2

What are some examples of innate leukocytes?

Answer 2

• Granulocytes (Kill parasites/bacteria, induce inflammation)
• Phagocytes (Phagocytose stuff)
• Mast cells (Worms and allergies)
• Natural Killer cells (Kill virally infected cells)

Question 3

What are some examples of acquired leukocytes?

Answer 3

• T Cells (cell mediated immunity)

- B Cells (Humoral immunity)

Question 4

Where do T-cells mature?

Answer 4

Thymus

Question 5

Where do B-cells mature?

Answer 5

Bone marrow

Question 6

Where are acquired leukocytes found in highest concentrations?

Answer 6

Lymph nodes (remember because acquired leukocytes are LYMPHocytes)

Question 7

What are the 5 types of antibodies?

Answer 7

• IgM (first response, pentamer)
• IgG (secondary response, most abundant)
• IgA (found in saliva and secretions, dimer)
• IgE (Cause mast cells to release histamine)
• IgD (function unknown)

Question 8

Characteristics of innate immunity?

Answer 8

• Non specific
• Induce inflammation
• Activated without prior exposure
• Phagocytosis
• Cytotoxicity
• Inflammation

Question 9

Where are leukocytes made?

Answer 9

Haematopoiesis in the bone marrow

Stem cells give rise to either:-

• Lymphoid progenitors (T & B cells, lymphocytes/acquired leukocytes)
• Myeloid progenitors (other white blood cells)

Question 10

Where are naive lymphocytes found?

Answer 10

Only circulate between lymph nodes and blood in spleen

Question 11

What happens when a naive T/B cell is exposed to an antigen?

Answer 11

• Naive cells + Ag —> swells into a blast cell
• Blast cell proliferates (via clonal expansion), creating effector and memory cells
• Effector cells circulate peripheral tissues (including site of injury/infection) and die off in absence of antigen
• Memory cells remain for FASTER and LARGER secondary response when exposed to same antigen

Question 12

Types of T-cells?

Answer 12

• Naive
• T Helper (Th1 - help B cells makes Ab. Th2 - Help innate cells uptake and kill microbes)
• T Cytotoxic (kill infected and tumour cells)
• T Regulatory (dampen inflammatory response)
• T Memory cells

All involved in cell mediated immunity

Question 13

Types of B cells?

Answer 13

• Naive
• Plasma cells
• Memory cells

All involved in humoral immunity.

Secrete antibody and present antigen to T-cells.