Lecture 1

Question 1

What affects the immune response?

Answer 1

Age
Nutritional Status
Genetics
Confounders/co-infections
Drugs
Stress
Smoking
*Immune cells are not static either!

Question 2

Define Immunology

Answer 2

The study of host defense against disease

Question 3

The divisions of the immune system

Answer 3

Innate (always present) and Adaptive (has to be induced, but highly targeted)

Question 4

Components of Innate Immunity

Answer 4

Humoral:
Complement, Cytokines/chemokines, antimicrobial peptides

Cellular:
Monocytes-Macrophages, dendritic cells
NK cells
Granulocytes-Mast cells, eosinophils, basophils, neutrophils

Question 5

Components of Adaptive immunity

Answer 5

Humoral:
Antibodies

Cellular:
B cells
T cells (Helper, cytotoxic, regulatory)

Question 6

Define Barriers of immune system

Answer 6

Passive defenses
always present
effective at keeping 99.9% of pathogens out

Question 7

Name the barriers

Answer 7

Skin
Mucus membranes
Antimicrobial peptides
Degrading Enzymes
Iron chelators
Movement
Normal flora
Acidic/dry environments

Question 8

Define Detectors

Answer 8

Identify the “non self”

signal to other cells something is going on

Question 9

Name some detectors of the immune system

Answer 9

Pattern Recognition receptors-toll like receptors (TLRs), Danger associated molecular patterns (DAMP)
Complement system
Misc Receptors-Fc receptors, cytokine, acute phase protein receptors (mannose binding lectin, C reactive protein, serum amyloid A, P (SAA,SAP), Acid glycoprotein (AGP)

Question 10

Responders

Answer 10

The cells that mount an immune response

Question 11

Name some innate responders

Answer 11

Granulocytes
-neutrophils
-eosinophils
-basophils
-mast cells
Mononuclear phagocytes
-macrophages
-dendritic cells
Lymphocytes
NK cells

Question 12

Name some Adaptive Responders

Answer 12

Lymphocytes like B and T cells

Question 13

What mediates Immunity?

Answer 13

Organs, cells and molecules and

soluble components, cellular components, tissues

Question 14

When does an immune response occur?

Answer 14

Occurs following a stimulus, but immune system is always working

Question 15

Innate immunity sees what?

Answer 15

Whole pathogen or protein

Question 16

Adaptive immunity sees what

Answer 16

The epitope (a 10-20 AA’s)

Question 17

Cells of the Innate immune system can kill what?

Answer 17

The pathogen or the infected host cell

Question 18

Define soluble components of the immune system

Answer 18

• Released by immune cells .fibroblasts, epithelial cells hepatocytes, others
• Affect differentiation and activities of immune cells
• Can have direct action on invading pathogens or tumors

Question 19

Define cellular components of immune system

Answer 19

• Innate responses and Adaptive responses
• both innate and adaptive rely on wbc’s (leukocytes), which originate in the bone marrow from hematopoietic stem cells
• Depending on the signals (receptor binding and cytokines) encountered, hematopoietic stem cells differentiate along a myeloid pathway or a lymphoid pathway

Question 20

Name the types tissues of immune system

Answer 20

Primary organs

Secondary organs

Question 21

All cells of the immune system arise from where?

Answer 21

bone marrow precursors

cytokines drive differentiation down each pathway

Question 22

Where can you find white blood cells?

Answer 22

both in the tissue and the blood
they migrate into tissues naturally, while others remain in the blood until there is inflammation or tissue injury
ex. neutrophils can be quickly distributed to the tissues in response to an inflammatory stimulus

Question 23

Define cytokines

Answer 23

small proteins that are chemical messengers and coordinate the immune response
they also:
drive immune cell differentiation
regulate the activation of immune cels
direct movement of immune cells

Question 24

Neutrophils

Answer 24

Innate immune cell
also called PMNs
Most numerous innate immune cell
responsible for phagocytosis and digestion of bacteria and particles
2 day lifespan
multilobed nuclei and granules that stain with neutral dyes

Question 25

Do species differ in their % of blood leukocytes

Answer 25

yes | 20-30% in ruminants, 60-75% in carnivores

Question 26

Macrophages

Answer 26

``` Innate immune cell Most important phagocytic cell!! produce cytokines, regulates homeostatic processes and wound healing Phagocytic, kills bacteria -has fc and complement receptors Secrete pro-inflammatory cytokines Present processed antigens to t cells Live longer than the neutrophils do ```

Question 27

Dendritic cells

Answer 27

Innate cell Phagocytic found in low #'s in tissues found in skin epitheila, intestinal, reproductive mucosae migrate to draining lymph nodes following pathogen uptake MOST IMPORTANT antigen presenting cell a link between innate and adaptive in that the present antigens to the t cells of the adaptive immune system

Question 28

Eosinophils

Answer 28

Innate cell Also a PMN, present in low numbers (0.1-3% of blood cells) After release from bone marrow, the migrate to spleen for maturation, then migrate to tissues, especially CT under mucosal surfaces Kill extracellular parasites (have fc receptors on surface, bind antibodies) Bilobed nuclei, cytoplasmic granules that stain with eoosin the granules contain phosphatase, peroxidase, toxic proteins 12 day life span

Question 29

Basophils

Answer 29

Innate cell a PMN present in v low numbers (~.05%) mutilobed nuclelus cytoplasmic granules stain with basophilic dyes such as hematoxylin Granules contain inflammatory molecules (histamine, seratonin) not normally distributed in tissues kill parasites due to presence of antibody receptors

Question 30

Mast cells

Answer 30

Innate cell Long life span reside near blood vessels normally distrubuted in tissues, primarily CT and near body surfaces different morphologies in different tissues Kill parasides due to presence of FceRI which binds IgE cytoplasmic granules contain inflammatory molecules (vasoactive amines like histamine, seratonin)

Question 31

NK cells

Answer 31

Innate cell Lymphocytic lineage, but are not T cells process different antigen receptors than B or t cells do not require thymus for maturation ~15% of blood lymphocytes mostly in secondary lymphoid organs kill tumor cells and virally infected cells Process an Fc receptor allowing them to bind many types of antibodies

Question 32

Innate immunity

Answer 32

ubiquitous in body tissues | ready to respond immediately to threats

Question 33

Innate immune cells are:

Answer 33

sentinel cells directly cytotoxic for bacteria, fungi, parasites (nk cell is exception to this) inflammatory thru secretion factors that -activate other cells -recruit immune cells to sites of iflammation disrupt cell membranes of bacteria fungi, parasites

Question 34

Innate Immune components are:

Answer 34

soluble factors that regulate function of other cells in body damage invading microorganisms promote wound healing

Question 35

Adaptive Immunity is..

Answer 35

Specific to a given molecule mediated by lymphocytes (b,t cells) which have receptors for antigens on pathogens or particles, provide specific immunity, provide memory of specific antigens

Question 36

Bcells

Answer 36

``` produce antibodies (humoral immunity) antibodies bind antigens and interact with components of innate immune system ```

Question 37

T cells

Answer 37

recognize processed antigen on host cells (cell mediated immunity) helper t cells activate or regulate activites of other cells cytotoxic t cells kill host cells bearing a foreign antigen

Question 38

Where do b and t cells differentiate

Answer 38

b-bursa, bone marrow | t-thymus

Question 39

where are lymphocytes found

Answer 39

blood, lymphoid organs

Question 40

Clonal selection

Answer 40

each lymphocyte ca see a few antigens once selected, they undergo clonal replication based on a cell having the correct receptor for a very small defined part of a larger antigen (epitope) other cells of the same type with different receptors are not activated