Immunosero Lec M3

Question 1

3 Main functions of Cellular Migration

Answer 1

• Deliver of leukocytes of myeloid lineage (mainly neutrophils and monocytes) from the circulation into tissue sites of infection or injury
• Delivery of lymphocytes from their sites of maturation
  (bone marrow or thymus) to peripheral (secondary) lymphoid organs

-Delivery of effector lymphocytes from the secondary lymphoid organs in which they were produced to sites
of infection in any tissue, where they perform their protective functions

Question 2

Deliver of leukocytes of myeloid lineage (mainly neutrophils and monocytes) from the circulation into
tissue sites of infection or injury

Answer 2

1st Main Function

Question 3

Where are neutrophils and monocytes be typically found?

Answer 3

Peripheral Blood (Blood vessels)

Note
Neutrophil and monocytes would just continuously circulate along with blood From the circulation, whenever there would
be an infection or injury, they would travel from the circulation to specific tissue sites of infection or injury

Question 4

Delivery of lymphocytes from their sites of maturation
(bone marrow or thymus) to peripheral (secondary) lymphoid organs

Answer 4

2nd Main Function

Question 5

Lymphocytes that have not yet reached or matured in the bone marrow or thymus

Answer 5

Immature Lymphocytes

Note

Small lymphocytes could either stay in the bone marrow where they would become mature B cells

Question 6

Lymphocytes that have matured either in the bone marrow or the thymus

Answer 6

Mature Lymphocytes

Note

basically a mature B cell or T cell

Question 7

T cell or B cell that have not been exposed to antigens

Answer 7

Naive Lymphocytes

Note

Have not yet encountered bacteria,
fungi, or viruses.
No antigenic stimulation

Question 8

main organ for
hematopoiesis

Answer 8

Bone Marrow

Question 9

Bone marrow creates _________ that would become lymphocytes

Answer 9

Stem Cells

Question 10

In the bone marrow, what are two things that would happen in dealing with lymphocytes

Answer 10

Certain percentage of small lymphocytes will either

• stay in the bone marrow
  or
  -they would travel to
  the types

Note

If they stay in the bone marrow, the small lymphocytes would become B cells

If they travel in the thymus, they would
become T cells.

Question 11

From the circulation, the Mature T cells and Mature B cells would now go to the secondary lymphoid organs, specifically
_______ and _______

Answer 11

lymph nodes and spleen

Question 12

While the mature b cells and t cells are travelling to the secondary lymphoid organs, they
would now be considered ______ T cells and B cells.

Answer 12

Naive

Note

They have basically not yet been exposed to antigenic components

Question 13

When they go the secondary lymphoid
organs (lymph nodes and spleen), they
would encounter antigens which will make them now become an ________ T cell and B cell

Answer 13

Activated

Note

From the activated form, they would be
required to go to different sites of infection to perform their protective function

Question 14

T cell would either develop into ______ and ______

Answer 14

• T helper cell
• T Cytotoxic cell

Question 15

B cell will become ______ or ______

Answer 15

• Plasma Cell
• Memory Cell

Question 16

Delivery of effector lymphocytes from the secondary lymphoid organs in which they were produced to sites
of infection in any tissue, where they perform their protective functions

Answer 16

3rd Main Function

Note

Effector is somewhat synonymous to
activated

Question 17

Sentinel cell refers to _____

Answer 17

Macrophage

Question 18

Macrophage of the liver

Answer 18

Kupffer Cells

Question 19

Whenever the sentinel cells encounter an
antigen, it would now release certain chemicals known as _______

Answer 19

Cytokines

Question 19

Whenever the sentinel cells encounter an
antigen, it would now release certain chemicals known as _______

Answer 19

Cytokines

Question 20

capable of creating molecules known as
chemokines

Answer 20

Microbes and Necrotic Tissue

Question 21

Adhesion of circulating leukocytes to vascular
endothelial cells is mediated by 2 classes of molecules which are

Answer 21

• SELECTINS
• INTEGRINS

Note

Selectins and integrins have ligands or their
receptors

Question 22

Are plasma membrane carbohydrate-binding adhesion molecules that mediate an initial step of low-affinity adhesion of circulating leukocytes to endothelial cells lining post capillary venules

Answer 22

Selectins

Note

Selectins are typically found in the surface of
the endothelium and they would only provide a weak initial attachment or affinity

Question 23

What are two types of selectins?

Answer 23

P-selectin (CD62P) and E-selectin (CD62E)

Question 24

It is stored in cytoplasmic granules of endothelial cells, and is rapidly redistributed to the luminal surface in response to histamine from mast cells and thrombin generated during blood coagulation

Answer 24

P-Selectin (CD62P) *Note* named because it was first found in platelets P (Platelets) - selectin Inside the endothelial lining, there would be cytoplasmic granules Inside the cytoplasmic granules is where P-selectin is

Question 25

How does P-selectin redistribute itself?

Answer 25

Due to histamine from mast cells and thrombin generated during blood coagulation

Question 26

is the one responsible for converting fibrinogen into a fibrin

Answer 26

Thrombin *Note* Thrombin is generated whenever you would have an injury or wound

Question 27

Fibrin would act as a _____ to capture cell decrease

Answer 27

Net

Question 28

is synthesize and expressed on the endothelial cell surface within 1 to 2 hours in response to the cytokines interleukin-1 (IL-1) and tumor necrosis factor (TNF), which are produced by tissue sentinel cells (DCs and macrophages) in response to infection

Answer 28

E-Selectin (CD62E) *Note* Microbial products such as lipopolysaccharide (LPS) also stimulate E-selectin expression on endothelial cells E-selectin is found in the endothelial cell surface In the endothelial lining, there would be endothelial cells. Inside the endothelial cells is where E-selectin is.

Question 29

They are usually produced due to the presence of IL-1 and tumor necrosis factor (TNF)

Answer 29

E-Selectin

Question 30

What causes the expression of your E-selectin or which cytokine causes the expression of E-selectin?

Answer 30

IL-1 and tumor necrosis factor *Note* Whenever macrophage secreted cytokine such as IL-1 and tumor necrosis factor, it would cause the expression of E-selectin

Question 31

A third selectin that is expressed on leukocytes and not on endothelial cells. L-selectin on neutrophils promotes the adhesion of these cells to endothelial cells that are activated by IL-1, TNF, and other inflammatory cytokines.

Answer 31

L-Selectin (CD62L) *Note* This is not part of the main selectins It is found in leukocytes and not on endothelial cells

Question 32

In adaptive immunity, this selectin is required for naïve T and B lymphocytes to home into lymph nodes through specialized blood vessels called high endothelial venules (HEVs)

Answer 32

L-Selectin (CD62L)

Question 33

Entry way of naive T and B cell

Answer 33

High Endothelial Venules (HEVs) *Note* The one that serves as a guide is the L-selectin

Question 34

Which selectin is found in leukocytes?

Answer 34

L-Selectin

Question 35

are cell surface proteins that mediate adhesion of cells to other cells or to extracellular matrix, through specific binding interactions with various ligands

Answer 35

Integrins *Note* Found in cell surface or WBC

Question 36

what stimulate leukocyte movement and regulate the migration of leukocytes from the blood to tissues

Answer 36

Chemokines *Note* are a large family of structurally homologous cytokines that stimulate leukocyte movement and regulate the migration of leukocytes from the blood to tissues. Chemokines would call WBC to the site of injury. Cytokines would also call WBC but cytokines mainly used to activate the different adhesion molecules

Question 37

The name chemokine is a contraction of

Answer 37

Chemotactic Cytokine

Question 38

Chemokines are subdivided into 4 groups. What are the 4 groups?

Answer 38

1st group - CC chemokines 2nd group - CXC chemokines 3rd group - C chemokines 4th group - CX3C chemokines

Question 39

Chemokine plays two roles of inflammation, what are these?

Answer 39

- Increased adhesion of leukocytes to endothelium. - Migration of leukocytes through blood vessels and toward the site of infection or tissue damage *Note* In inflammatory reactions, chemokines serve to recruit circulating leukocytes from blood vessels into extravascular sites

Question 40

Involved in the development of lymphoid organs, and they regulate the traffic of lymphocytes and other leukocytes through different regions of secondary lymphoid organs.

Answer 40

Chemokines *Note* Chemokines are required for the migration of DCs from sites of infection into draining lymph nodes

Question 41

Leukocyte recruitment from the blood into tissues requires adhesion of the leukocytes to the endothelial lining of postcapillary venules and then movement through the endothelium and vessel wall into the extravascular tissue.

Answer 41

Leukocyte-Endothelial Interaction

Question 42

There are four things that would occur whenever there would be a WBC endothelial interaction.

Answer 42

- Rolling - Integrin activation by chemokines - Stable adhesion - Migration through endothelial *Note* Process of Leukocyte-Endothelial interaction' 1. Selectin-mediated rolling of leukocytes on endothelium 2. Chemokine-mediated increase in affinity of integrins 3. Stable integrin-mediated arrest of leukocytes on endothelium 4. Transmigration of leukocytes through the endothelium

Question 43

Leukocyte-endothelial interaction would begin when ever macrophages would be stimulated by microbes such as

Answer 43

- Antigen - Bacteria - Fungi

Question 44

Known as the characteristics of the WBC which they are capable of squeezing through the tissues

Answer 44

Diapedesis

Question 45

serves as a homing signal to find where the organisms is

Answer 45

Chemokines

Question 46

What is the first leukocyte to migrate to sites of infection or tissue injury?

Answer 46

Neutrophils *Note* Monocyte would follow a few hours after