Tools needed for Host Defense Lecture Sep 30

Question 1

What are all immune system cells descendants of?

Answer 1

A pleuripotent hematopoietic stem cell found int he bone marrow

Question 2

What two signallers will regulate the repertoire of cells produced during hematopoiesis?

Answer 2

growth factors and cytokines

Question 3

What are the two important subdivisions of hematopoiesis projenitors?

Answer 3

Common Lymphoid Progenitors and Common Myeloid Progenitors.

Question 4

The myeloid cells include…

Answer 4

Neutrophils, Eosinophils, Basophils, Monocytes and Dendritic Cells. Monocytes transform into macrophage upon entry to tissues. Mast cells are assume to be populated into tissues by blood borne precursor cells produced in the Bone Marrow.

Question 5

The lymphoid cells include…

Answer 5

B-cells, T-cells, NKT cells and NK cells

Question 6

How do B cells and plasma cells (further differentiated B cells) differ in how they express immunoglobulin?

Answer 6

B cells express immunoglobulin as the antigen receptor and will secrete homologou immunoglobulins as antibody

Plasma cells do NOT express surface immunoglobulin but secrete large amounts of antibody

Question 7

What are the granular white blood cells?

what are the non-granular white blood cells?

Answer 7

THe granular inclue the leukocytes (like mast cells and basophils) - they collect their cytokines in granules and undergo triggered release

The non-granular cells include monocytes and lymphocytes (they immediately release their cytokines, so there is no triggered release)

Question 8

Where do blood cells develop?

Answer 8

All the stem cells are located in the bone marrow

the myelocytes and lymphocytes will develop in the bone marrow

the T cells will develop in the thymus (newborn through puberty only)

Question 9

What do macrophages mainly use to destroy bacteria?

Answer 9

ROS

Question 10

How do monocytes and macrophages differ?

Answer 10

the monocyte is in circulation

macrophages are in the tissue

otherwise they are the same thing

a macrophage is more irregularly shaped.

Question 11

What is the main role of a mast cell?

Answer 11

Start inflammaton by releasing histamine, heparin, and TNF alpha

Question 12

What three things will cuase mast cell degranulation?

Answer 12

antibodies coopted by the mast cell bind the antigen and cross link

injury

complement activation

Question 13

What is the main role of a neutrophil?

Answer 13

They are the first respinders that phagocytose and activate bactericidal mechanisms. then they die.

Question 14

How are neutrophils released into circulation?

Answer 14

THey are short lived and produced on demads…

a large number of cirulatory neutrophils are bound to the surface of bascular beds

stress with cortisol and epinephrine will stimulate demarginalization - release of neutrophils into circulation

Question 15

What are the most prevelane leukocytes?

Answer 15

neutrophils

Question 16

How do neutrophils recognize invaders?

Answer 16

They have receptors for antibody Fc regions and receptors for complement

Question 17

What are eosinophils associated with?

Which antibodies mediate their action?

Answer 17

They are involved in attack on helminthic parasites and allergies

they have receptors for IgE

They secrete peroxidase and leukotrienes

Question 18

Where are basophils located?

What do they release?

Answer 18

Basophils are located in the lymph nodes are are associated with histamine release in hypersensitivity responses. They sample the same materials the T cells are sampling in the lymph nodes and are activated by IgE

They are the samllest and least abundant

the main function is considered to be regulation of the inflammatory processes

Question 19

What do NK cells screen for?

What will they induce?

Do they have an antigen receptor?

Answer 19

They screen for absence of MHC Class 1

if no MHC is presented, they will induce apoptosis in the target cell

they do NOT have an antigen receptor

Question 20

WHat do dendritic cells do?

Answer 20

They will pick up material rom sites of inflammation using PAMP receptors.

They will then present the antigens on MHC Class II displays to the naive T cells to activate them

Question 21

What are some characteristics of cytokines?

Answer 21

they are soluble mediates that are small glycoprptines synthesized on demand

they act through autocinre and paracrine methods only

THey are uiquitously found

THey direct cellular differentiation through sequential cascade patterns

Question 22

WHat cytokines direct cell development?

Answer 22

growth factors initiate the whole thing, but the interleukins (IL3, 4, 5, 6, and 7) take over to refine the development process as needed

Question 23

What MCH class is expressed on dendritic cells, macrophges and B cells?

Answer 23

MHC class 2

Question 24

What cells express MCH class 1?

What’s presented on class 1?

Answer 24

all cells except for RBCs

The antigen display is all self proteins

Question 25

What determines what kind of T cell a T0 cell will develop into?

Answer 25

the type of PAMP presented by the dendritic cell on its MCH class 2