LECOM MMS Immunology 2C Adaptive Immunity

What is the response time of Innate Immune Response?

Fast

What is the recognition of Innate Immune Response?

Non-specific

What are the cell types of Innate Immune Response?

NK cells, macrophages

Does Innate Immune Response have memory?

No

Does Innate Immune Response have specificity?

Limited

Does Innate Immune Response have diversity?

Limited

What is the response time of Adaptive Immune Response?

Slow; takes weeks

What is the recognition of Adaptive Immune Response?

Specific

What are the cell types of Adaptive Immune Response?

T cells, B cells, and Antibodies

Does Adaptive Immune Response have memory?

Yes

Does Adaptive Immune Response have specificity?

Yes

Does Adaptive Immune Response have diversity?

Yes

What are the Features of Adaptive Immunity?

• Specificity:

- Activated by and responds to a specific antigen

• Diversity:

- Recognizes variety of antigens

• Clonal expansion:

- Naïve activation leads to proliferation of clones

• Memory:

- Recalls an antigen previously seen

• Specialization:

- Response optimal against different types of microbes

• Nonreactivity to self:

- Only responds to foreign substances and ignores self

What are the two types of Adaptive Immunity responses?

Humoral Immunity and Cell-mediated Immunity

What does Humoral Immunity contain?

- B cells: Membrane bound antibodies

- Plasma cells: Secrete antibodies

What does Cell-mediated Immunity contain?

T cells

* CD4+ and CD8+

- Cytokines or killing

What are the Peripheral (Secondary) Lymphoid Organs/Tissues?

Lymph nodes, spleen, mucosal, and cutaneous immune system

What do the Peripheral (Secondary) Lymphoid Organs/Tissues function to do?

Concentrate APCs, antigens, and lymphocytes

In Peripheral (Secondary) Lymphoid Organs/Tissues, are B and T cells segregated?

Yes

What is the function of the Lymph nodes?

- Lymph drained by lymphatic vessels from tissues

- Travels to the lymph nodes before reentering blood circulation

- Gives APCs a chance to find antigens

Where will B cells always be found?

Primary follicle

Where are T cells always found?

Paracortex

Where are activated B or T cells found?

Germinal centre of secondary follicle

How do B or T cells enter from blood back into the lymph?

High Endothelial Venule (HEV)

Where are Plasma cells found?

Medullary cords

How do cells enter the lymph?

Afferent lymphatic

How do cells exit the lymph?

Efferent lymphatic

What does the spleen do to blood-borne antigens?

The spleen filters blood and removes blood-borne antigens by exposing them to immune cells in the white pulp.

Where are B cells located in the spleen?

B cell zone (follicle)

Where are T cells located in the spleen?

T cell zone (periarteriolar lymphoid sheath PALS)

Where do Naive lymphocytes go?

From blood to peripheral lymphoid organs

What happens when Naive lymphocytes are activated?

They migrate to the site of infection

What do B Cell Receptors (BCR) recognize?

Macromolecules

Do B Cell Receptors (BCR) have a unique specificity?

Yes

- Variable (V) region on heavy and light chain

What do you need to activate B cells?

Igα and Igβ

What do T Cell Receptors (TCR) recognize?

Antigens displayed on MHCs

In TCRs, what does each clone have?

A unique specificity

What do TCRs contain?

CD3 and ζ

Where are B cells made?

Bone marrow

Where do B cells mature?

Bone marrow

What happens when B cells are activated?

Leads to plasma cells

What is the function of plasma cells?

Secrete antibodies

Where do CD4+ Helper T cells develop?

Bone marrow

Where do CD4+ Helper T cells mature?

Thymus

What happens when CD4+ Helper T cells are activated?

- Secretes cytokines to stimulate other immune responses

OR

- Down regulate the immune response

Where do CD8+ Cytotoxic T cells develop?

Bone Marrow

Where do CD8+ Cytotoxic T cells mature?

Thymus

What happens when CD8+ Cytotoxic T cells are activated?

Will find infected (or tumor) cells and kill them

What will CD8+ Cytotoxic T cells release?

Perforin and Granzyme just like NK cells

What is Clonal Selection?

Selection of 1 B cell

What is Clonal Expansion?

Making clones of 1 B cell

What will most B cells differentiate into?

Plasma cells

What will happen to a small amount of B cells?

They will become memory B cells

What is Immunologic Memory?

It is the ability of the adaptive immune system to respond faster, stronger, and more effectively when it encounters the same antigen again.

Dendritic cell enters a lymph node through which lymph node structure?

Afferent Lymphatic Vessel

Which lymph node structure is where activated B cells will be found?

Germinal center

During recirculation, a lymphocyte enters the lymph node from the blood through which lymph node structure?

HEV

Which location in the lymph node is where plasma cells are primarily located?

Medullary cords

A researcher is currently designing an experiment to further investigate clonal selection and expansion. She is discussing the project with a peer and is asked what cells do you plan on using? Which of the following cells should the researcher use?

A. B cells

B. Dendritic cells

C. Eosinophils

D. Macrophages

E. Neutrophils

A. B cells

For the following statements indicate if they are describing BCRs or TCRs:

1. This receptor protein is only ever membrane-bound

2. This receptor has 2 identical antigen binding sites

3. This receptor is a Y-shaped immunoglobulin molecule

4. This receptor only has 1 antigen binding site

5. This receptor requires CD3 for signal transduction

6. This receptor protein comes in membrane-bound or secreted form

1. TCR

2. BCR

3. BCR

4. TCR

5. TCR

6. BCR