Intro to the Immune System

Question 1

What cells are found in the cortex of a lymph node?

Answer 1

B Lymphocytes

Question 2

What do B cells in the cortex do after encountering antigen?

Answer 2

They form a germinal center and undergo proliferation

Question 3

What cells are found in the paracortex of a lymph node?

Answer 3

T Lymphocytes

Question 4

What cells are found in the medulla of a lymph node?

Answer 4

APC’s (essentially macrophages)

Question 5

What are the cells of the myeloid lineage?

Answer 5

Eosinophils, Basophils, Neutrophils (PMN’s), Monocytes, Macrophages, Dendritic cells

Question 6

What is the main function of eosinophils?

Answer 6

Protection against parasites

Question 7

What is the main function of basophils?

Answer 7

Protection against parasites (similar to eosiniphils)

Question 8

What is the main function of Neutrophils?

Answer 8

Short lived, primary phagocytic cell of the innate immune system

Question 9

What is the function of monocytes?

Answer 9

Circulating precursors of tissue macrophages

Question 10

What is the function of macrophages?

Answer 10

Mononuclear phagocytic cells in the tissue, derived from monocytes, participate in innate and adaptive immunity

Question 11

What is the function of dendritic cells?

Answer 11

Antigen presentation to lymphocytes

Antigen presenting cells

Question 12

What are the cells of the Lymphoid Lineage?

Answer 12

Large lymphocytes: NK cells

Small lymphocytes: B and T cells

Question 13

What is the function of NK cells?

Answer 13

Innate immunity to viruses and tumors

Question 14

What is the function of B cells?

Answer 14

Ab production

Question 15

What is the function of T cells?

Answer 15

Cytokine production

Question 16

Granulocyte CD?

Answer 16

CD15+

Question 17

Monocyte CD?

Answer 17

CD14+

Question 18

Dendritic CD?

Answer 18

CD11c+

Question 19

T Lymphocyte CD?

Answer 19

All T lymphocytes are CD3+

Question 20

T helper lymphocyte CD?

Answer 20

CD3+ CD4+

Question 21

Cytotoxic T lympocyte CD?

Answer 21

CD3+ CD8+

Question 22

B lymphocyte CD?

Answer 22

CD19+

Question 23

NK cell CD?

Answer 23

CD56+

Question 24

What are the proportions of immune cells in the blood?

Answer 24

Neutrophils (40-75%) > Lymphocytes (20-50%) > Monocytes (2-10%) > Eosinophils (1-6%) > Basophils (NL-MEB)

Question 25

Where are blood borne pathogens filtered and create an immune response?

Answer 25

The spleen

Question 26

The lymph node collects antigen from where?

Answer 26

Epithelium and connective tissue

Question 27

What are self antigen (markers of self?)

Answer 27

MHC molecules, which in humans are made up of various HLA types

Question 28

What are the HLA types of Class I MHC, and where are they found?

Answer 28

MHC type I: HLA type A, B, C Found in virtually all tissues

Question 29

What are the HLA types of Class II MHC, and where are they found?

Answer 29

MHC type II: HLA type DP, DQ, DR Found exclusively in B cells, monocytes/macrophages, and Dendritic cells (These are antigen presenting cells, they carry MHC class II in addition to MHC class I)

Question 30

What are components of the innate immune system?

Answer 30

Barriers (skin, tears), Macrophages, Granulocytes, NK cells

Question 31

What are components of the adaptive immune system?

Answer 31

T cells (cell-mediated) and B cells (humoral)

Question 32

What is cell mediated immunity, and against what is it directed?

Answer 32

killing of cells by cytotoxic T lymphocytes (CTL's) and the production of cytokines directed against infected cells, defective cells, and non-self cells

Question 33

What is humoral immunity and against what is it directed?

Answer 33

antibodies produced by immunoglobulin-producing B cells (plasma cells) directed against cell associated and free floating antigen

Question 34

What do T helper cells secrete when they are activated by antigen, and what does it do?

Answer 34

cytokines --> are absolutely necessary for other T and B cells to terminally differentiate

Question 35

What happens to a cytotoxic T cell when it is activated by antigen?

Answer 35

It produces perforin & granzymes that it will release directly into the target cell via cell-cell contact

Question 36

Do B cells require antigen presentation in the context of self?

Answer 36

No -- B cell Ig binds to the antigen itself, without the need for self antigen

Question 37

What is necessary for a T helper cell to bind Ag?

Answer 37

A T helper cell (CD4+) requires Ag presented in the context of MHC class II

Question 38

What is necessary for a cytotoxic T cell to bind Ag?

Answer 38

A cytotoxic T cell (CD8+) requires Ag presented in the context of MHC class I

Question 39

Describe the process after a B cell recognizes a foreign Ag

Answer 39

A B cell Ig recognizes Ag presented by an antigen presenting cell The Ig/Ag is endocytosed and is broken down along with the Ag attached to it The B cell places Ag peptide in the context of MHC Class II and displays it on the surface The B cell Ag/MHC-II stimulates a helper T cell, which proliferates, terminally differentiates, and produces cytokines The cytokines stimulate B cells to terminally differentiate into plasma cells which secrete Ig against the specific Ag The cytokines also stimulate cytotoxic T cells to proliferate and differentiate and migrate to kill infected cells

Question 40

Give some examples of passive immunity. Is it short or long term?

Answer 40

Mother passing Ab to her infant, antiserum Short term

Question 41

Give some examples of active immunity. Is it short or long term?

Answer 41

Naturally acquired (infection), vaccination Long term

Question 42

What are the two types of autoimmune diseases? | Give some examples of each

Answer 42

Organ specific: MS, type I diabetes, Hashimoto's Thyroiditis Systemic: Systemic Lupus (SLE), Rheumatoid Arthritis