Immunology Lecture 2

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How is the immune system classified?

"1. Primary Lymphoid Organs - Development and maturation of lymphocytes"

The central or primary lymphoid organs generate lymphocytes from immature progenitor cells.

The thymus and the bone marrow constitute the primary lymphoid tissues involved in the production and early selection of lymphocytes.

"2. Secondary Lymphoid Organs - Trap Antigens, Allow lymphocytes to interact and react"

Secondary or peripheral lymphoid organs maintain mature naive lymphocytes and initiate an adaptive immune response. The peripheral lymphoid organs are the sites of lymphocyte activation by antigen. Activation leads to clonal expansion and affinity maturation. Mature lymphocytes recirculate between the blood and the peripheral lymphoid organs until they encounter their specific antigen.

Secondary lymphoid tissue provides the environment for the foreign or altered native molecules (antigens) to interact with the lymphocytes. It is exemplified by the lymph nodes, and the lymphoid follicles in tonsils, Peyer's patches, spleen, adenoids, skin, etc. that are associated with the mucosa-associated lymphoid tissue (MALT).

How does the primary and the secondary lymphoid organs connect to one another?

Blood and lymphatic system join the two organ types

Allows transfer of lymphocytes from point of origin to point of action

What constitutes the primary lymphoid organs?

"1. Primary Lymphoid Organs - Development and maturation of lymphocytes"

The central or primary lymphoid organs generate lymphocytes from immature progenitor cells.

The thymus and the bone marrow constitute the primary lymphoid tissues involved in the production and early selection of lymphocytes.

The immune system involves single organs only T/F

Explain answer

Immune system is extremely complex - Involves multiple organs and tissues

Conceptually explain what a leukocyte is

White blood cells, or leukocytes are cells of the immune system involved in defending the body against both infectious disease and foreign materials.

Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell.

They live for about three to four days in the average human body. Leukocytes are found throughout the body, including the blood and lymphatic system.

Participate in the immune response

What are the only leukocytes that directly participate in the immune response?

Lymphocytes (Directly interact with antigens; Specific antigen receptors)

Exhibit all characteristics required for the immune response

Diversity, specificity, memory and self/non-self recognition

What are the 4 characteristics required for the immune response?

What cells directly participate in this?

1. Diversity
2. Specificity
3. Memory
4. Self/non-self recognition

Lymphocytes (Sub-class of leukocytes)

Many cells in the immune response system execute what role in the immune response system?

1. Accessory role, often involved in activation
2. May enhance phagocytosis
3. May induce production / secretion of signaling molecules

Only lymphocytes involved in:
1. Diversity
2. Specificity
3. Memory
4. Self/non-self recognition

How are all blood cells created?

What does this involve?

Hematopoiesis - formation of blood cellular components.

Involves differentiation of hematopoietic stem cells (HSC; Notice this in the figure where this is the beginning portion)

What are the characteristics of HSC? What does HSC stand for?

HSC = Hematopoietic stem cells

1. Capable of differentiating into all types of blood cells
2. Self renewing capability - maintain population by cell division

Where does hematopoiesis begin?

Embryonic yolk sac for mammals

Initially, what do HSCs differentiate into exclusively?

Red Blood Cells

When do HSCs migrate to the spleen and liver?

3rd month

In month three, where do HSCs migrate to?

Spleen and Liver

In month seven, where do HSCs migrate to?

Bone marrow

When do HSCs migrate to bone marrow?

Month seven

What does the term pluripotent mean?

Nika - Capable of differentiating into any or all cell types

Immortal?

During differentiation of hematopoiesis, what are the two types of progenitors that are capable of differentiating into?

LYMPHOID PROGENITOR CELL
Gives rise to:
1. T cells
2. B cells
3. Dendritic cells
4. Natural killer cells (NK)

MYELOID PROGENITOR CELL
Gives rise to:
1. Macrophages
2. Neutrophils
3. Eosinophils
4. Basophils
5. Mast cells
6. RBC
7. Megakaryocytes that give rise to platelets

What do lymphoid progenitor cells give rise to?

LYMPHOID PROGENITOR CELL
Gives rise to:
1. T cells
2. B cells
3. Dendritic cells
4. Natural killer cells (NK)

What do myeloid progenitor cells give rise to?

MYELOID PROGENITOR CELL
Gives rise to:
1. Macrophages
2. Neutrophils
3. Eosinophils
4. Basophils
5. Mast cells
6. RBC
7. Megakaryocytes that give rise to platelets

What is the term of the step that is performed when a cell differentiates into either the lymphoid or the myeloid cell?

What are the consequences of this?

Committal step

Consequence:
1. Can no longer differentiate into any cell type
2. No longer have capacity for self renewal

HSCs have many possible fates (Outcomes), how is this made possible in the cell? What needs to happen?

Cells need instructions due to having many possible fates

What molecule functions as a signaling molecules for HSC stem cell differentiation?

Cytokines

Cytokines (Greek cyto-, cell; and -kinos, movement) are small cell-signaling protein molecules that are secreted by numerous cells and are a category of signaling molecules used extensively in intercellular communication.

Cytokines can be classified as proteins, peptides, or glycoproteins; the term "cytokine" encompasses a large and diverse family of regulators produced throughout the body by cells of diverse embryological origin

What are the consequences for the different cytokines that are stimulated?

Type of cytokine that stimulates HSC to proliferate dictates fate

How many different cytokines are possible?

What is the role of each cytokine?

Over 60 different cytokines

Cytokines are small polypeptide (Proteins) molecules

Role:
Each activates transcription of different subset of genes

Type of cytokine that stimulates HSC to proliferate dictates fate

Where does differentiation of stem cells occur?

Network of bone marrow STROMAL CELLS

Conceptualize what stromal cells are

In cell biology, stromal cells are connective tissue cells of any organ, for example in the uterine mucosa (endometrium), prostate, bone marrow, and the ovary.

They are cells that support the function of the parenchymal cells of that organ.

Fibroblasts, immune cells, pericytes, and inflammatory cells are the most common types of stromal cells.

Stromal cells (in the dermis layer) adjacent to the epidermis (the very top layer of the skin) release growth factors that promote cell division.

This keeps the epidermis regenerating from the bottom while the top layer of cells on the epidermis are constantly being "sloughed" off of the body.

What does differentiation of stem cells within the network of bone marrow stromal cells generate?

Hematopoietic-inducing microenviornment

What's that mean?

Matrix with bound or diffusible growth factors (cytokines)

How were growth factors identified?

Found by practical evidence (empirical data)

Verifiable by observation or experience rather than theory or pure

What do growth factors have the capability of generating?

Stromal cell layer required for differentiation

What is the hypothetical outcome of progenitor cells that lack growth factors?

Progenitor cells will not grow unless media supplemented with growth factors

If progenitor cells are not growing, what is a plausible explanation?

Media has not been supplemented with growth factors

Where did colony stimulating factor (CSF) generate its name?

Growth factors allowed progenitor cells to form colony on stromal cells

There are many classes of CSF (Colony Stimulating Factors). What does each one do differently? What is the consequence of each CSF?

Each activates a different transcription factor

Types of CSF used to stimulate progenitor cell dictates fate

What are the 4 types of CSF (Colony Stimulating Factors)?

1. MULTILINEAGE CSF (IL-3)

2. MACROPHAGE CSF (M-CSF)

3. GRANULOCYTE CSF (G-CSF)

4. GRANULOCYTE-MACROPHAGE CSF (GM-CSF)

What do combinations of CSFs along with cytokines do?

How is this made possible?

"Instruct" HSCs as to what type of cell to differentiate into

Accomplishes by activating specific transcription factors at specific stages of differentiation

What is the life span of a RBC and a T cell?

RBC = 120 Days

T cell = 20-30 years (memory T cell)

Reason for vaccines lasting for a decade or too

Must get new vaccine so that you remain immune

What is the consequence if there is insufficient replenishment of blood cells?

Anemia or immune deficiencies

What is the consequence if there is over abundant replenishment of blood cells?

Cancer (Leukemia)

What is anemia a result of?

consequence if there is insufficient replenishment of blood cells

What is leukemia a result of?

Leukemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts".

consequence if there is over abundant replenishment of blood cells

Conceptualize what leukemia is

Leukemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts".

consequence if there is over abundant replenishment of blood cells

What are the 4 factors involved in regulation of hematopoiesis?

Four factors involved in regulation:

1. Control of types and amounts of cytokines produced by stromal cells in bone marrow

2. Production of cytokines by other cells (activated T cells)

3. Regulation of cytokine receptor expression in HSC and progenitor cells

4. Removal of cells by programmed cell death (apoptosis)

What are the "steps" and characteristics of apoptosis?

Cell decreases in volume

DNA degraded (Chromatin)

Nucleus fragments

Cell ultimately fragments into numerous membrane bound "blebs"

During apoptosis, what occurs when membrane "blebs"?

Macrophages will phagocytize all the intracellular components contained

Yellow cell is macrophage which will engulf the cell

What is the primary differences in apoptosis and necrosis?

Apoptosis Necrosis
Natural: Yes No

Effects: Beneficial Detrimental

Apoptosis is the process of programmed cell death (PCD) that may occur in multicellular organisms. Programmed cell death involves a series of biochemical events leading to a characteristic cell morphology and death.

Necrosis is the premature death of cells and living tissue. Necrosis is caused by external factors, such as infection, toxins or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death.

Seperate fingers in embryo development and prevent tumor (homeostatis between cell death rate and mitosis rate) these intercellular content damage neighbouring cells cause inflammation.
definition: programmed cell death the cell or tissue damage due to external factors.

process: membrane blebbing, shrinkage of cell, nuclear collapse (nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation), appoptopic body formation. Then, engulf by white blood cells

Dying cell swells and burst,releasing the intercellular content.

What does necrotic cell death have the consequence of?

Release of cytosolic components (cause inflammation; which may actually damage tissues)

What are some factors that activate apoptosis?

1. bax
2. bcl-XS
3. fas
4. caspase

What are some factors that inhibit apoptosis?

1. bcl-2
2. bcl-XL

How are factors regulated to allow proper production and removal of blood cells?

Temporally (of or relating to time)

What two things in combination, activate B cells promoting rapid proliferation in regards to apoptosis in the immune response?

Combination of:

1. Antigen interaction with receptor
2. Cytokine stimulation activates B cell, proliferates rapidly

As cytokine receptor expression increase in regards to apoptosis in the immune response, what is an effect?

Bcl - 2 expression decreases

Bcl - 2 expression with decrease when what occurs? (In respect to apoptosis in the immune response)

Cytokine receptor expression increases

In regards to antigen presence, when will occur with cytokine production and expression? (Think about apoptosis in the immune response)

As long as antigen is present cytokines continue prevent apoptosis

Once antigen is cleared, cytokine production ceases

If the Block to apoptosis is removed, what happens in reference to the B-cell?

Effector B cell gets depleted through apoptosis

What cell in the immune system is extremely critical?

Lymphocytes (Type of leukocyte)

(Directly interact with antigens; Specific antigen receptors)

Exhibit all characteristics required for the immune response

Diversity, specificity, memory and self/non-self recognition

What percentage of the total WBC % and lymph % constitute lymphocytes?

WBC = 20-40%

Lymph = 99%

Lymph = Lymph is the fluid that circulates throughout the lymphatic system. The lymph is formed when the interstitial fluid (the fluid which lies in the interstices of all body tissues) is collected through lymph capillaries.

As the blood and the surrounding cells continually add and remove substances from the interstitial fluid, its composition continually changes and it changes into lymph fluid.

It is then transported though lymph vessels to lymph nodes before emptying ultimately into the right or the left subclavian vein, where it mixes back with blood.

What are the three classes of lymphocytes?

1. T cells

2. B cells

3. Null cells

How are the different types of lymphocytes classified?

List the types of lymphocytes?

1. T cells
2. B cells
3. Null cells

Classified based on surface markers

What is characteristic about null cells?

They do not express any distinguishing markers

AKA Natural Killer (NK) cells

What do T and B cells have in common?

They progress through a similar cell cycle

What is the term used for cells that have not encountered an antigen?

Comment on name and size

Naive = Term of a cell that has not encountered an antigen

Size = Small = 6µm

What is the outcome of a cell that is arrested in G₀ phase?

Undergoes apoptosis if antigen is not encountered

What happens if an antigen interacts with the cell surface?

An antigen will stimulate progression through the cell cycle

Cells become larger (15 µm) = Lymphoblast

Lymphoblast completes progression through cell cycle

Division generates effector cells and memory cells

Conceptualize what a lymphoblast is

Lymphoblasts are immature cells which typically differentiate to form mature lymphocytes. Normally lymphoblasts are found in the bone marrow, but in acute lymphoblastic leukemia (ALL), lymphoblasts proliferate uncontrollably and are found in large numbers in the peripheral blood.

The size is between 10 and 20 μm.

Although commonly lymphoblast refers to a precursor cell in the maturation of leukocytes, the usage of this term is sometimes inconsistent.

The Chronic Lymphocytic Leukemia Research Consortium defines a lymphoblast as "A lymphocyte that has become larger after being stimulated by an antigen.

Lymphoblasts look like immature lymphocytes, and were once thought to be precursor cells.". Commonly, when speaking about leukemia, "blast" is used as an abbreviation for lymphoblasts.

Conceptually understand what a plasma cell is

B lymphocyte effector cell
Lacks surface associated B cell receptor (Antibody)
Divides rapidly, produces and secretes antibodies (2000/second)
Dramatically different intracellular structure

Extensive ER
Multiple Golgi
Essential for ↑ secretion
Short life spans (1-2 days)

What is the reasoning behind Extensive ER and Multiple Golgi for a plasma cell?

Dramatically different intracellular structure

They need tons of ability to secrete lots and lots of antibodies and need extensive "shipping coordinators" that can allow all these antibodies to become available.

Divides rapidly, produces and secretes antibodies (2000/second)

Hopes that energy consumptions is WORTH THE INVESTMENT and that you produce sufficient quantities of antibodies

What does a plasma cell lack?

Lacks surface associated B cell receptor (Antibody)

What are the three types of T cells?

1. T-h cells

2. T-c cells

3. T-reg cells

Conceptualize what the role of a T-h cell is

T-h cell = T-helper cell

Activated to produce effector and memory cells

Effector cells produce cytokines essential for activation for immune response

Conceptualize what the role of a T-c cell is

Activated to produce effector and memory cells (Same as T-helper)

Effector cell is the cytotoxic T cell

Mediates killing of altered hos cells or foreign cells

What role do cytotoxic T cells and T helper cells have in common?

Activate to produce effect cells

Helper - Also makes memory cells
Cytotoxic - Makes Immune cells

What do the effector cells of T-h cells produce?

Cytokines essential for activation of immune response

What do the effector cells of T-c cells produce?

Mediates killing of altered hos cells or foreign proteins

What is the T reg role?

T reg common marker with Th (CD4), suppresses the immune response

What is CD4?

In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein found on the surface of immune cells such as T helper cells, monocytes, macrophages, and dendritic cells.

CD4 is a co-receptor that assists the T cell receptor (TCR) with an antigen-presenting cell. Using its portion that resides inside the T cell, CD4 amplifies the signal generated by the TCR by recruiting an enzyme, known as the tyrosine kinase lck, which is essential for activating many molecules involved in the signaling cascade of an activated T cell.

Can you distinguish T and B cells underneath a microscope?

Can you distinguish them at all? What does this distinguishment allow for?

No

Yes; through differences in proteins on the surface

Allows for:
1. Discrimination between T and B
2. Discrimination of T-c and T-h
3. Determine stage of maturation of B, T-c and T-h

Crazy

What does CD stand for in immunology?

Comment on what they are used for

Comment on number around

Cluster of Differentiation

These are surface markers collectively referred to as CD markers

Over 250 exist

CD markers present perform critical roles in B cell function, not just for cool looks

What are B cells named for?

Site of maturation

Initially, this ID process stemmed from avian (Birds) studies

B cells were maturating in the bursa of Fabricius which was the site of hematopoiesis, a specialized organ that, as first demonstrated by Bruce Glick and later by Max Cooper and Robert Good, is necessary for B cell (part of the immune system) development in birds.)

Appropriate for humans = Bone Marrow

What is the distinguishing characteristics on B cells?

Presence of antibodies on surface of the cell

1.5e⁵ = 150000 antibodies

CD markers present perform critical roles in B cell function

What is the role of B220 (CD45R)?

B220 (CD45R) - transduces signal required for activation

What is the role of MHC Class II molecules?

MHC CLASS II MOLECULES - allow B cell to present antigens to TH cells

What is the role of CR1 (CD35)?

CR1 (CD35) - receptor for complement component C3b

What is the role of CR2 (CD21)?

CR2 (CD21) - receptor for complement component C3d

What is the role of FcγRII (CD32)?

FcγRII (CD32) - receptor for Fc region of IgG

What is the role of B7-1 (CD80) ?

B7-1 (CD80) - interaction with TH cells

What is the role of B7-2 (CD84) ?

B7-2 (CD84) - interaction with TH cells

What is the role of CD40 ?

CD40 - interaction with TH cells

Which CD markers interact with T-h cells?

B7-1 (CD80) - interaction with TH cells

B7-2 (CD84) - interaction with TH cells

CD40 - interaction with TH cells

Which CD markers are a receptor for Complement C3b and C3d respectively?

CR1 (CD35) - receptor for complement component C3b

CR2 (CD21) - receptor for complement component C3d

Which CD marker is a receptor for Fc region of IgG?

FcgRII (CD32) - receptor for Fc region of IgG

Which class of molecules allow B cell to present antigens to T-h cells?

MHC class II molecules

What are T cells named for?

Site of maturation; which takes place in the thymus

What do T-cells possess?

Be specific in:
Specificity
Similarity
Recognition capabilities

Membrane receptor for antigen - TCR (T-cell receptor)

1. Distinct from antibody associated with surface of B cell

2. Only similarity is antigen binding cleft

3. Cannot recognize free antigen, only in context of MHC

Do T cells have CD proteins? What is the caveat?

Yes they do

Some are common to T cells, others are distinct to T-h and T-c

What do all T cells express?

CD3 (Signal Transduction)
CD28 (B cell interaction)
CD45 (signal transduction)

What is CD3 used for?

Signal Transduction

What is CD28 used for?

B cell interaction

What is CD45 used for?

Signal Transduction

Which Cluster of Differentiation do T-h cells express?

What is the function of this CD marker?

CD4 - Recognize peptides presented by MHC Class II, only activated by antigen presenting cells

What is the role of CD4 marker?

CD4 - Recognize peptides presented by MHC Class II, only activated by antigen presenting cells

Activation of T-h cells expressing CD4 results in what?

What is the downstream effect of this activation?

Production / secretion of cytokines

Cytokines are essential for activation of T-c and B cells

Why is the type of cytokine produced important when discussing T-h specific CD marker activation?

Type of cytokine produced dictates the type of response

What are the two types of Cytokine responses when discussing T-h specific CD marker activation?

1. TH1 response produces cytokines triggering inflammation and activation of TC and MF (CMI)

2. TH2 response produces cytokines triggering proliferation of B cells and antibody production (humoral)

What is a TH1 response when discussing T-h specific CD marker activation?

TH1 response produces cytokines triggering inflammation and activation of TC and M∅ (Cell Mediated Immunity)

What is a TH2 response when discussing T-h specific CD marker activation?

TH2 response produces cytokines triggering proliferation of B cells and antibody production (humoral)

Which T helper cell response in responsible for Cell Mediated Immunity and which is responsible for humoral immunity?

1. TH1 response produces cytokines triggering inflammation and activation of TC and MF (CMI)

2. TH2 response produces cytokines triggering proliferation of B cells and antibody production (humoral)

What is the CD marker that is activated by T-c cells?

What is its function?

CD8 - Recognizes peptides presented by MHC class I, only activated by altered self

When is the only time CD8 is activated?

What is the result of activation?

Activated only by altered self by T-c cells

CD8 - Recognizes peptides presented by MHC class I, only activated by altered self

Activation results in differentiation into a CYTOTOXIC T LYMPHOCYTE (CTL)

Activation of CD8 results in what?

Activation results in differentiation into a CYTOTOXIC T LYMPHOCYTE (CTL)

What are the 4 characteristics of Cytotoxic T Lymphocytes?

1. Do not secrete cytokines

2. Do not participate in signaling of other immune effectors

3. Can now recognize and kill altered self cells

4. Sole purpose is destruction of infected/altered cells

What's important to remember about what Null Cells do not produce?

What else are they deficient at doing?

Do not produce membrane associated antigen receptors

No immunological memory or specificity, consist mainly of NK cells

Draw the difference in a B cell and a plasma cell

What is the critical role of NK cells / Null Cells?

Critical in destruction of tumor and viral infected cells

What are the two ways in which null cells can participate in destruction of cancer cells?

1. Can mediate killing directly (recognized depletion of surface antigens)

2. Can undergo ANTIBODY DEPENDENT CELL-MEDIATED CYTOTOXICITY (ADCC)
- Antibody attaches to cell due to presence of foreign antigen
- Fc receptor on null cell attaches to antibody

What is antibody dependent cell mediated cytotoxicity?

Antibody attaches to cell due to presence of foreign antigen
- Fc receptor on null cell attaches to antibody

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) is a mechanism of cell-mediated immune defense whereby an effector cell of the immune system actively lyses a target cell, whose membrane-surface antigens have been bound by specific antibodies. It is one of the mechanisms through which antibodies, as part of the humoral immune response, can act to limit and contain infection. Classical ADCC is mediated by natural killer (NK) cells

What are the characteristics of NK 1-T cells?

Hybrid between NK cell and T cell

Possess T cell receptor

Binds to MHC like molecule CD1

Express CD 16 - typical of NK cells

Actively kill cells like cytotoxic T cells

Actively secrete cytokines that stimulate immune system like TH cells

Believed to be rapid response to early infection, takes time for TH to become activated and proliferate

Do NK1-T cells possess T-cell receptor?

Yes

What are NK 1-T cells a hybrid between?

What are the similarities between T cells and what are the similarities of NK cells?

NK cell and T cell

Express CD 16 - typical of NK cells

Actively kill cells like cytotoxic T cells

Actively secrete cytokines that stimulate immune system like TH cells

What CD do NK 1-T cells express?

CD16 - Typical of NK cells

What do NK 1-T cells bind to?

Bind to MHC like molecule CD1

What is believed about NK1 - T cells in there functional role?

Believed to be rapid response to early infection, takes time for TH to become activated and proliferate

What are the two cells that comprise the mononulcear phagocytic system?

1. MONOCYTES - circulate in blood, non-phagocytic

2. MACROPHAGES - monocytes differentiate into MF when they exit the blood stream and enter into tissues

Monocytes are phagocytitic?

Where do they circulate?

Yes

Blood

What is the primary difference in a monocyte and a macrophage?

MACROPHAGES - monocytes differentiate into MF when they exit the blood stream and enter into tissues

What are the morphological changes that accompany the change from a monocyte to a macrophage?

1. Cells becomes much larger (5 to 10 fold), becomes phagocytic

2. Number and complexity of organelles increases

3. Increases production of hydrolyitic enzymes

4. Capable of production of soluble factors (cytokines)

What are the names of different macrophages within different tissue. Name all of them

1. Alveolar MF - reside in lung
2. Histocytes - reside in connective tissue
3. Kupffer cells - reside in liver
4. Mesangial cells - reside in kidney
5. Microglial cells - reside in brain
6. Osteoclasts - reside in bone
7. Intestinal - GI tract

What are the macrophages that reside in the:

lung?
In the kidney?
Brain?
Bone?
GI tract?
Connective tissue?

1. Alveolar MF - reside in lung
2. Histocytes - reside in connective tissue
3. Kupffer cells - reside in liver
4. Mesangial cells - reside in kidney
5. Microglial cells - reside in brain
6. Osteoclasts - reside in bone
7. Intestinal - GI tract

How does a macrophage change when it moves to different tissue?

Only the nomenclature changes

What state are macrophages in when they enter tissue?

What do they need to do in order to perform role in immune system?

Resting state

They need to be activated

What are five mechanisms that can Wlead to macrophage activation?

1. Phagocytosis of particulate antigens (bacteria) can activate

2. Cytokines produced by TH enhance activity

3. Mediators of inflammatory response (histamine)

4. Bacterial cell wall components

5. γ-interferon produced by TH cells

Are NK-1 Cells capable of recognizing antigens?

No

Are monocytes weakly or strongly phagocytic?

Weakly phagocytoic

Conceptually understand what diapelsis is

The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue.

What are the macrophages that reside in the alveoli?

Alveolar MF - reside in lung

What are the macrophage that reside in connective tissue?

Histocytes - reside in connective tissue

What are the macrophage that reside in liver?

Kupffer cells - reside in liver

What are the macrophage that reside in kidney?

Mesangial cells - reside in kidney

What are the macrophage that reside in brain?

Microglial cells - reside in brain

What are the macrophage that reside in bone?

Osteoclasts - reside in bone

What are the macrophage that reside in GI tract?

Intestinal - GI tract

What form of macrophage is the most phagocytic form?

The activated macrophage are more phagocytic than the resting macrophage

What are the differences in activated macrophages and resting macrophages?

Activated MF are more phagocytic than resting MF

Also produce more hydrolytic enzymes, more capable of killing engulfed microbes

Increase secretion of mediators of inflammatory response

Increase secretion of cytotoxic proteins, clears pathogens

Increased expression of MHC class II, increased ability to activate TH cells

Once TH cells activated, secrete cytokines that further activate MF

Therefore MF and TH work synergistically to activate each other

If you have an increased expression of MHC class II receptors, what is the result (reference consequences of macrophage activation)

Increased expression of MHC class II, increased ability to activate TH cells

Once TH cells activated, secrete cytokines that further activate MF

Therefore MF and TH work synergistically to activate each other

What is the primary role of an activated macrophage?

Engulf undesirable material - phagocytosis

What is the difference in reference to exogenous material and endogenous material (phagocytosis)

Also, is phagocytosis complex or simp

May be exogenous material
Particulate matter (dirt)
Whole microorganisms

May be endogenous matter
Dead or damaged tissue
Cell debris
Blood clots

VERY complex involving several steps

How can you conceptualize chemotaxis?

CHEMOTAXIS

phagocytic cell attracted to infection - microbial products, components of WBC or damaged tissues, complement

Conceptualize Adherence in phagocytosis

ADHERENCE - attachment of phagocyte to organism, may be inhibited by presence of capsule, may require OPSONIZATION if capsule present

Conceptualize ingestion in phagocytosis

INGESTION - involves pseudopods, fusion of pseudopods results in internalization, internalized organism in specialized vacuole - PHAGOSOME

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