Basophils, Eosinophils, and Monocytes

Question 1

Basophils

Answer 1

• matures in BM
• basophilic granules (lots so difficult to observe maturation)
• bilobed nucleus
  circulate in blood until directed to inflamed tissue
• 60-hour lifespan; anti-apoptotic

Question 2

this is critical for basophil differentiation

Answer 2

IL-3

contributes to long lifespan (60 hrs)

Question 3

these initiate and mediate allergic response

Answer 3

• basophils
• receptors for IgE
• type I hypersensitivity

Question 4

these regulate immune response and releases cytokines to regulate T-helper cells

Answer 4

basophils

Question 5

these assist eos in control of helminth infections

Answer 5

basophils

Question 6

Basopenia

Answer 6

low basophils (disorder); hard to assess due to the low number of basophils

Question 7

eosinophils

Answer 7

• bilobed nucleus; azurophilic granules
• IL-5 critical for proliferation and survival
• concentrated at mucosal surfaces
• remains in circulation for about 18 hrs
• reside in tissues for 2-5 days

Question 8

T or F. eosinophils act as antigen presenting cells

Answer 8

T!

Question 9

Charcot-Leyden protein

Answer 9

• eosinophil
• lysophospholipase
• hydrolyzes different types of phospholipid membranes

Question 10

eosinophil cationic protein

Answer 10

destroys membranes

Question 11

major basic protein of eosinophilic granules

Answer 11

disrupts membranes

Question 12

eosinophil peroxidase

Answer 12

generates toxic radicals

Question 13

histaminase

Answer 13

produced by eos; inhibits histamine

Question 14

10% of leukocytes

Answer 14

monocytes

Question 15

monocytes are derived from…

Answer 15

granulocyte-monocyte progenitor cells

Question 16

housekeeping functions of monocytes

Answer 16

• remove debris
• destroy senescent RBCs and stores iron
• production of proteins, enzymes, interleukins, complement, growth factors, etc.

Question 17

monocytosis

Answer 17

caused by inflammation, infections, hypersensitivity, tissue repair, neutropenia, drugs, stress, malignancies

Question 18

monocytopenia

Answer 18

• rare ; other cytopenia involved

- aplastic anemia, EBV chemo, or steroid therapy

Question 19

Niemann-Pick disease

Answer 19

• lipid storage disease of monocytres (def of sphingomyelinase)
• accumulation of sphingomyelin in macrophages giving foamy cytoplasm with lipid filled vesicles

Question 20

Basophil granules

Answer 20

• histamine
• chondroitin sulfates
• eosinophilic chemotactic factor
• prostaglandin D2
• leukotrienes
• interleukins

Question 21

Gaucher disease

Answer 21

• monocyte disorder
• lysosomal lipid storage
• def in B-glucocerebrosidase
• glucocerebroside accumulates in macs giving cytoplasm a wrinkled/striated appearance

Question 22

largest reservoir of monocytes

Answer 22

• red pup of spleen

- releases them in response to tissue damage

Question 23

T or F. basophils are phagocytic

Answer 23

F! non-phagocytic

Question 24

basophil granules

Answer 24

• histamine = hypersensitivity + inflammation
• chrondroitin sulfates = heparan sulfate
• eiosinophilic chemotactic factor
• prostaglandin D2 (vasodilation)
• leukotrienes (mediates inflammation)
• interleukins

Question 25

type I hypersensitivity

Answer 25

• IgE mediated
• first exposure = B cells produce IgE which bind to mast cell and basophil membranes
• second = antigen binds IgE causing cross-linking and degranulation
• symptoms = vessel dilation, airway constriction, itching, mucous secretion

Question 26

Basophilia

Answer 26

• most common: MPN
• allergic rhinitis
• hypersensitivity to food or drugs
• chronic infections/inflammatory conditions
• bee stings

Question 27

Mast cells

Answer 27

• lots of granules and dispersed chromatin
• not “true” leukocytes
  > derived from hematopoietic precursors
  > mast cell progenitors travel from BM to tissues to mature
• involved in both innate ad adaptive immunity (effector cells in allergic reaction)

Question 28

where are mast cells found?

Answer 28

• skin and mucous membranes (skin, intestines)

- long lifespan in tissues

Question 29

eosinophil functions

Answer 29

• immune regulation: acts as antigen-presenting cells
• hypersensitivity: activation + regulation of basophils and mast cells, release IL-8 to activate neuts and T-cells, dampens effect of monocytes and basophils (via histaminases)
• regulate inflammation: inactivate substances released by basophils and mast cells
• destroy helminthic paasites
• allergic disorders (asthma)

Question 30

Eosinophils release this to activate neutrophils and T cells

Answer 30

IL-8

Question 31

eosinophil phagocytosis

Answer 31

• kills parasites too large to be phagocytosed
• via IgE complement coating the parasite
• T cells and basophils release interleukins to attract eosinophils
• eosinophils bind tightly to parasite and release granular contents
• frustrated phagocytosis

Question 32

eosinophilia

Answer 32

• allergies
• parasitic infections
• drugs reactions
• malignancies
• skin disorders
• pulmonary disorders

Question 33

major cytokine causing proliferation of monocytes

Answer 33

macrophage colony-stimulating factor

Question 34

T or F. monocytes are released directly into circulation once mature

Answer 34

T!

Question 35

T or F. Monocytes have a marginating and circulating pool in the peripheral blood

Answer 35

T!

• remain in circulation for 3 days
• responds to infection/inflammation immediately
• becomes resident cells
• lifespan ranges from hours (inflammatory macs) to 21 days (Kupffer cells)

Question 36

Monocyte functions in innate immunity

Answer 36

• recognize bacterial pathogens
• produce inflammatory cytokines
• phagocytosis
• synthesize nitric oxide (Cytotoxic)

Question 37

adaptive immunity functions of monocytes

Answer 37

• macs and dendritic cells are APCs

- activate B and T lymphs