11-5-13 10AM Qualtieri Acute and Chronic Inflammation Lecture and CILS

8/14/2019 11-5-13 10AM Qualtieri Acute and Chronic Inflammation Lecture and CILS

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Inflammation Lecture and CILSLecturer: Julianne Qualtieri, MD11/5/13 Lecture; 11/6/13 CILS

Learning Objectives:

1. Define acute and chronic inflammations.

2. Contrast acute and chronic inflammations in regard to common causes and

morphologic manifestations. Identify acute or chronic inflammation in a microscopic

image.

3. Define granulomatous inflammation and list causative agents. Identify

granulomatous inflammation in a microscopic image.

4. Describe the vascular events associated with acute inflammation.

5. Describe the sequence of cellular events involved in leukocyte extravasation and

phagocytosis.

6. Identify the molecules that are primarily involved in leukocyte rolling, endothelial

adhesion, transmigration and interstitial migration.

7. Describe basic pathophysiologic mechanisms involved in chronic inflammation.

8. List important chemical mediators of inflammation.

9. List important actions of chemical mediators.

10. Describe systemic manifestations of inflammation.

Key Words:

Inflammation

Acute inflammation

Chronic inflammation

Granulomatous inflammation

Extravasation

Phagocytosis

Rolling

Adhesion

Transmigration

Chemical mediators

Blood and Lymphatics: Immunology Infrastructure

Fundamentals of Cellular Medicine Course November 7th

, 2013 10am

Julianne Qualtieri, M.D. [email protected]

Vocabulary or key words presented in session:


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bone marrow hematopoietic stem

cell (HSC)

differentiation thymus

-cytosis -penia neutrophil monocyte

eosinophil basophil lymphocyte plasma cell

lymph lymph node cortex lymphoid follicle lymph node medulla

macrophage dendritic cell innate immunity adaptive immunity

Objectives: At the end of this session the student will:

1. Diagram the basic life cycle of a hematopoietic stem cell and how this pertains to normalhematopoiesis and the development of stem cell disorders.

2. Describe anatomic structures needed for surveillance of the entire human body against

pathogens.3. Describe the major differences and similarities between innate and adaptive immune

responses and which types of leukocytes are involved in each.

4. Explain the events necessary to complete an adaptive immune response to a foreign antigen

and where each event occurs in the body.

5. Become familiar with complete blood count (CBC) and peripheral blood smear abnormalities

and how these can be used to guide patient diagnosis and treatment.

Assigned Reading: R&C: PBD, 8thEd., Chapter 2 (pp. 43-77).

Reading Assignments:

Guyton & HallMedical Physiology

Chapter 33: Macrophage and neutrophil responses during inflammation

through Leukopenia pp. 428-431

Chapter 33: Beginning through Lifespan of white blood cells pp. 423-424

Chapter 34: Beginning through Millions of specific types of lymphocytes

are stored in the lymphoid tissue pp. 433-435

Robbins and CotranPathologic Basis of Di sease

Chapter 6: Tissues of the immune system pp. 188-190

NOTES:

11/5/13 Lecture Acute/Chronic Inflammation


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Types of inflammatory responses Acute inflammation Chronic inflammation Granulomatous inflammation

Why does inflammation occur? Inflammation is the bodys protective response to eliminate pathogens and removeinjured tissuesremove injured tissues. Injuries from chemical physical and micro

trauma.

Body has a set way to deal with insult -- given sequence of innate events that occur uponinsult to the body (first line defense, reproducible) before a more specific response can be

deployed.

Coordinated dance between vascular, tissues and recruited cells (immune cells). Alsoadaptive response (with lymphocytes in the blood, spleen)this often requires the extra-vascular accumulation of blood/lymphocytes. We want a very protein rich environment in

our area of injurywant lots of immune cells/blood flow (Involves extravascular

accumulation of fluid and leukocytes). Eloquent system. Injury can happen anywhere/anytime. Our body works to be ready at alltimes to acquire an injury anywhere. These coordinated events involve:

Vascular Reactions Local Tissue Reactions Recruitment of Innate and Adaptive Immune cells

Balance of inflammation is needed to prevent unwanted responses (below). Excessive response

Sepsisbody is trying to wall off/fight of bacterial infections, some cytokinescannot be neutralized and get into the circulation causing some of the

inflammation events throughout the entire body -- which is bad. Inappropriate response

Autoimmune diseasesin response to our own antigens Allergic reactionsarent noxious to us, but our body determines as noxious.

Ineffective response Immunodeficiency statesdont have an appropriate response to any trigger

Inflammation is easily recognizable clinically.

4 Cardinal sign of inflammation --- Heat, Redness, Swelling & Pain

Often come about quite rapidly

ACUTE INFLAMMATION: Arises quickly Short durationprovided it is an effective response Hyperemiaincreased blood (accounting for redness/ blood) Neutrophils WBC

Causes of acute inflammation:

Infection


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Foreign bodies -- immune system is military based, looking for non-self (splinter, micro-organism, etc)

Tissue necrosis -- dead tissue Trauma Physical and chemical agents -- chemical exposure, caustic agents

Immune reactions -- inappropriate antibody response (autoimmune, allergic, etc.)

**Chronic inflammation involves a lot of the same eventsjust the timeline is different and a lot

of the cellular components are different Many of the mediators between acute and chronic

inflammation are similar

Vascular Reactions Vasodilationhistamine secreted by mast cells in the damaged tissuesincreased blood

flow to the area, lots of proteins, nutrients, cells to fight infectionaccounts for rednessand heat

Increased permeabilityhappens in the venules, occurs through a variety of mechanisms:

endothelial cells retract creating gaps (endothelial gaps) provide flux of fluid,plasma proteins and cells into the tissuethis gets the cells right to the site of theinfection/trauma.

transcytosis physical defect: Sometimes the trauma just damages the tissue releasing a lot of

fluid, also releasing hemorrhage.

edema (tumor): This is often the result of the influx of fluids, plasma proteins andcells.

Vascular Stasis: Blood is typically whizzing by quickly. There needs to be vascularstasis, so the cell will dilate creating turbulent flow. This will get the leucocytes to jump

around and literally bump into the sides of the vessel. This has a similar theory to a

chemical reaction, the more they bump into it, the more likely they will be to bind to anendothelial cell.

Exudate vs. Transudate ExudateLocal cells release cytokines and they tell the endothelial cells to retract

allowing cells, proteins and fluid to come out for good. In an inflammatory reaction we

usuallyare dealing with an exudate (fluid that filter from the circulatory system intolesions or areas of inflammation).

Transudatesomething wrong with pressure, protein synthesisoncotic pressure. Fluidis literally squeezing out. This is typically pathologic. Abnormal. Not related to an

inflammatory responseNot good. Normal situations --balance. So that we dont swell up.

Cellular Reactions

Just getting a Leukocyte from the blood into the tissue is quite a project. Cells cantpass the cellular (capillary) epithelium (to keep so form hemorrhaging everywhere).

They pass via a controlled process, where we have just the cells we want leaving the

lumen while keeping the others (RBCs) within the blood vessels (lumen). Extravasationleaving of the cells from the blood into the tissues.


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Stasis is going to increase bumping against the walls Rolling to a stop

Selectins: express (on endothelial cells) just at the right time (only in areasof inflammation), because we dont want neutrophils sticking to the

surface of every vessel in the body. This would not be good. These are

expressed under the influence of cytokines. Neutrophils bind to selectinscausing them slowing down and cascade in a process called rolling Adhesion -- tight adherence to the epithelium in preparation for transmigration

Integrins: Binding of selectines and activation of neutrophils expressedintegrin on the surface of both the neutrophil and the endothelium cell.This tight binding of integrin is what allows the neutrophil to completely

stop and anchor in to get ready to squeeze through the endothelial cells.

Transmigration -- literally squeezing through the junctions of the epithelium. PCAM-1 (CD31): Allows transmigration, or squeezing through.

Marginationleukocytes being pushed to the edge of the vessel

Any defect in these molecules can cause clinical problems to fight off infections.

Chemotaxistells the cells Exactly where to go. Helps to cells locate the injury Leukocytes (cells) from the blood are attracted to the site of injury by a chemical

gradient of signaling. Chemical gradient triggers signaling which activates thecytoskeleton within the cells and they crawl towards the site of injury, propelled

by their cytoskeleton network.

Molecules that promote chemotaxis are often foreign moleculessuch as aminoacids unique to bacteria (Formyl-Methionyl)The body immediately says this

isnt a part of me and starts creating a chemogradients.

Activationactivation enzymes are closely coordinated, because we do not want themactivated in the wrong place or at the wrong time.

Signal the cell to adhere to endothelium, bind to tissues, create its own cytokinesto help bring in more cells and to create toxic molecules to actually kill the cell

PhagocytosisThe whole point of acute inflammation is to bring the immune cells to thesite of inflammation so that they can gobble up stuff phagocytosis.

Macrophages/Neutrophils are the main gobblers

Must recognize there is something to eat Enhance by recognition of strange chemical structures (bacterial cell wall),

opsinization or covering of a material with something such as compliment.

Phagocytic cells have receptors for compliment.If immunoglobins are

bound to a particle they will likely be recognized, because macrophageshave a Receptor for the FC portion of immunoglobins.

Engulf: We have binding of foreign thing. Need to get inside cytoplasm. Ifantibody binds compliment, triggers membrane of cell to undergo invagination

creating the phagosome. The purpose of this is to bring the microorganism/particle into its own compartment within the cell because we are going

to be destroying this micro organism by releasing some really toxic chemicals

which we do not want released to other tissues and other organisms.


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Eat (Kill/Degrade): largely by oxygen-dependent mechanisms (Reactive oxidativespecies ~~ bleach, which produce H2O2 that reacts with NO species causing free

radical damage) when a phagosome fuses with a lysosome. Most bacteria do nothave a way to respond to free radical damage. Bodys have ability to neutralize

free radicals.

Chronic Inflammatory states like atherosclerosis, Cancers, etc. This happenswhen our inactivaters (neutralize free radicals) get overwhelmed and we have tomuch free radical production.

Acute Inflammation Timeline

Edema -- rush of fluid (few hours)

Neutrophils -- day

Monocytes -- slower, but longer lived cell capable of phagocytosis and presentingantigens to activate other portions of the immune system if it is necessary... (couple days)

Typical time Course for Acute Inflammation 0-12 h: vasoactive changes edema 12-24 h: beginning infiltration of neutrophils 24-36 h: peak of neutrophil infiltration 36-96 h: influx of macrophages begin process of repair, granulation tissue, angiogenesis

and, in some cases, collagen deposition (patch over holesliterally) 96 h-3 wk: resolution or formation of a scar

Morphology of Acute Inflammation:

Appendicitis:o normal appendix: shiny outer surface and fine vasculature.

o inflamed appendix (acute appendicitis): inflammatory stimulus such as -- fecalmatter can back up and bacteria can clog it by bacteria proliferating. The localepithelium becomes injured, swollen, red, hemorrhage, white extradative material(composed of neutraphils,bacteria, etc) etc (from all the blood flow).

Acute Meningitis:o Causes inflammation along the meninges. Cerebral Disfunction. Lethal.

Can see a lot of little neutrophilslittle cluster of grapes, ants crawlingaroundmulti-lobated nuclei. Lots of neutrophils dying off, thats

why the nuclear material is becoming dark and pigmented, in addition

to the anucleic debris in there. Acute inflammatory cells in bacteria.

We like inflammation because it can help us combat microorganisms,

the problem is that the reactive species and harmful enzymes can bereleased outside of the cellNeutrophils only survive for about a day

and than they die off, which is when the toxic species can be released

and cause damage to our tissues. Lot of collateral damage (localdestruction) involved in acute inflammation. The body tries to avoid

this, but it would rather have some local destruction than an infection

that overtakes and overwhelms the organism.Option after acute inflammatory response happens:


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ResolvesMacrophages will eat up dead bacteria, cells will be cleared away through thelymphatics, completely normal tissue.

Neutrophils are a little over activated, the enzymes can destroy the vascular in the tissues.Resulting in an abscess. Which is a collection of neutrophils, bacteria, cell debris, which

cant really be cleaned up because the main supply route (to supply nutrients,

macrophages for fibrious, etc) has been cut off. The Neutrophils Shot their own foot.This will eventually result in healing, but will be more of a scar. Abscess's can be

difficult to treat. Often antibiotics are given to stimulate clearance of the micro organism,however antibiotics are transported through the vasculature which has been destroyed --

this is difficult. No way to get the antibiotics to the abscessrequire surgery to clear the

dead tissue.

Another option is maybe we didnt do such a good job clearing the agent so now it is timeto call out the special troops -- chronic inflammation which will increase angiogenesis,

bringing more nutrients to the area, more cells to gobble things up, lymphocytes (provide

specified killing power). Will typically result in chronic damage/fibrosis. The more

Macrophages that come in, the more fibrotic responses are elicited.

CHRONIC INFLAMMATION

Prolonged duration Concurrent tissue injury and repair Macrophages, lymphocytesandplasmacells

First line of defense has failed, need to bring in some more powerful weaponry, which is

mediated by macrophages, lymphocytes, plasma cells (these more powerful mechanisms have

their own kind of collateral damage). This is why we can get tissue injury.

Macrophages play roles in both acute and chronic responsesLymphocytes & Plasma cells: are ONLY seen in chronic responses NOT seen in acute

responses.

Chronic inflammation can start while acute inflammation is still present. (Back-Up) Can see both

at the same timenot separate entities

Common Causes of Chronic Inflammation: Basically didnt get rid of the agent

Acute Inflammation

Persistent Infections

Prolonged Irritationforeign substances

Autoimmunity

Macrophages are similar to a garbage truck, but

smart. Recruit other macrophages and secrete piecesof cells on their surface

Macrophages are produced via a feedback loopAntibodyB-Lymp


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Direct KillT-Lymph

Activaetion of Macrophages results in Tissue injury and Fibrosis. However, to much fibrosis canbe bad, harming organs. Tissue injury results by secreting reactive oxidative species.

Morphology of Chronic Inflammation:

Lots of lymphocytes, plasma cells (which make antibodies to neutralize) and macrophages laying

down fibrosis, bands of collage, forming nodules (characteristic of hepatitis). When chronic

inflammation occurs in the liver, like in Hep C, the biliary system can become chocked off andinhibit bile production.

Chronic Inflammation is present in rheumatoid arthritis resulting in joint deformalitieschronic

inflammation of the synovial, lymphocytes and plasma cellsr eacting to the bodys ownantibodies.

Granulomatous Inflammation: Special Form of chronic inflammation

Epithelioid Macropahges

Macrophage can eat, but not digest organism. Becomes multi-nucliate in their ownattempted to wall-off and neutralize the infection.

Causes:o TBo Fungalo Asbestos (Non-infectious)

Granulomas formwalled of infection/foreign particle

We probably have old granulomas because we have been exposed toHistoplasma

capsulatum fungalin the Ohio River Valley. If we had a weakened Immune system andwere unable to do this, this could become very dangerous.

Foreign body GranulomaCommon to see in pathologic specimens with previoussurgeriesdissolvable suture

Foreign material that is not pathologicwhatsoever.

Granulona does not equal Granulation Tissue:

Granulomainflammation/Walling Off organisms or Insult. Generally not helpful.

Granulation TissueHealthy, regenerative tissue with a lot of fibroblast laying downscar tissue. This is how the body heals itself. Good.

Chemical Mediators:

Come from cells/Liver(constantly synthesizing proteins)

Good that the liver is constantly creating these, so there is little lag time and control ofthe process. Want strong mediators to be carefully controlledwhile we want some of

the other ones around all the


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Chemical Mediators: A lot of them have checks and balances against one another (most ofthen can also have both pro- and anti- inflammatory responses)

Vasoactive amines --- histamine, vasodilation Plasma proteases --- break down destructive enzymes Arachidonic acid metabolites --- control inflammatory response Platelet-activating --- factor activation of epithelium migration Cytokines --- recruiting cells Chemokines --- Nitric oxide --- vasodilation Lysosomal enzymes ---

Reactive oxygen species --- Tissue Damage

Fever: Triggered by cytokines (TNF-alpha, IL-1 and IL-6)triggering the hypothalamus to

constrict the arterials and conserve heat, raising the body temperature. When the temperature is

raised we are capable of synthesizing heat shock proteinsthis can be done only when we have

a fever.

Leukocytosis: Elevated WBC, accelerated release from marrow and increased immature

neutrophils

During acute inflammation we have more proteins around to provide/scavenge nutrients to

eliminate tissue damage and enhance the immune response. Acute Phase Proteins: C-reactive proteinopsonization6 to 10 hours response timecan be used as a

laboratory test to evaluate the whole inflammatory burden in someones body.

Fibrinogencoagulation

Alpha(1)-antitrypsinprotease inhibitor

Haptoglobinbinds hemoglobin

C3 -- complement

Ceruloplasminbind copper


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Alpha(2)-macroglobulinprotease inhibitor

Systemic Effects of Inflammation:

Laboratory Evaluations of Inflammation:

White Blood Cell Count (How many leukocytes have been recruited?)o Normal: 4,50010,000 /microLo Leukocytosis: 10,00020,000 /microLo Leukemoid reactions are often confused pith acute leukemia, but there are no bad

effects from them

o Cell Type in the blood can help us tell what is going on Clinically

Neutrophilia Eosinophilia Monocytosis (become

macrophages)

Lymphocytosis

Bacterial InfectionsBurnsTissue Necrosis

Parasitic InfectionsAllergic DisordersColleen Vascular

Disease

Chronic InfectionsTBMalaria

IBD

Viral infectionBordetella pertusisi w/monocytosis in TB

Erythrocyte Sedimentation rate (ESR)o Lots of proteins will interfere with the net negative charge and the RBCs stick

together.


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o sediment more rapidly than monodispersed RBCso An increased sed rate is considered non-specific evidence of an inflammatory

process

C- Reactive Protein (CRP)o Secreted rapidly by the liver in response to inflammation

o Elevation persists while inflammation exists Serum Protein electrophoresis

o Serum proteins are classified on the basis of their electrophoretic mobility:

o albumin 1 2

Clinical Implications of the inflammatory response.

FYI: Leuko = White (When WBCs pile up, they look white)

11-7-13 Blood and Lymphatics NOTES:

Components of an Effective Immune System:

HeadquartersBone marrow Endless source of recruitsBone marrow

Bone Marrow: hematopoietic cells(Multipotent, self-renewal,

differentiation, special microenvironment, Can multiple without externalsignal, sometimes allowing it to get out of control --- this can often result

in a cancer (block in differentiation, and division goes on and on). Aplastic

anemia: STEM cells for RBCs die off.)

Erythroid Precursorswhere red cells come from hanging out onthe iron islands

Myeloid Precursors: thegranulocyteprecursor cell inbone marrow
http://en.wikipedia.org/wiki/Granulocytehttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Bone_marrowhttp://en.wikipedia.org/wiki/Granulocyte


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Megakaryocytes: produce plateletssit in sinusoids of bonemarrow and poop out platelets.

Lymphocytes Lymphocyte Primary Maturation

Occurs in the bone marrow

Ig gene rearrangement occurs in the bone marrow Assembly of the b-cell receptor in the bone marrow At his point they leave the bone marrow called

nave b-cells, they havent met their antigen

(epitope) yet. If they dont find their match, theywill die. Peripheral lymph node tissues are where

they will meet up. -- Only respond to epitopes that

are foreign to the body.

Granulocyteslymphocytes, etc develop from this. Majorcomponents of cellularity of Bone Marrow. Because a neutrophils

life span is 24h and we need a ton of them.

Granulocyte maturation: Major leukocytes of our blood.Start out as blasts in which the nucleus is the majorimportant organellehigh nucleus/cytoplasmic ratio.

As the cells mature, DNA condenses and nucleus shrinks. All this maturation occurs in the bone marrow. Only see mature form in the blood.

Plasma cells: produce antibodies Monocyte/macrophages

Stromal cells less clear that they are directly involved in disease processes,however they do provide support and lay down a nice supportive network

often via fibrogen.

Fibroblasts/reticulin Adipose -- bone marrow is replaced by fat eventually Osteoclasts/blasts Endothelial cellsplay important role in release of cells/signaling

Transportation Blood and Lymphatics Blood: Less direct Lymphatics: Express Shuttle, Direct connection to lymph nodes,

Coordinate Immune Response

Have to be careful, because the more transportation you open up, the morechance there is for intruders (microbes tumors cells) to get in. So you have

to be careful about this, so that they do not spread all over the place). Lymphatics also provide a drainage route. Lymph fluid will be dumped

back into the circulation.

Continuous surveillanceMacrophages

Ingests Digests Presents antigen to regional authorities

Lymph nodes for tissues


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Langerhans cellsresident dendritic cells in the skinwillpick up the antigen (if it enters through the skin) and start

secreting cytokines. Acute inflammatory cascade will begincytokine/chemokine release, local epithelial cells will

start producing selectin (basically waving a flag to any

passing neutrophil to come and help) there lymphocyteswill slow down, adhere and enter the tissue helping to fightthe infection. Macrophages will digest, display and take the

antigen to the lymphatic's. This is already mobilizing that

adaptive immune response. Macrophages are educating the lymphocytes in the

lymph nodes about a new antigen, seeing if their antibody

fits within it.

B cell will go through hyper mutation, in hopes of gettingan even better match for its antigen. Lot of deleterious

mutations so a lot of less good b-cells.

Germinal center is where lot of death and destructionoccurs. A lot of macrophages in here eating up dead b-cells that

didnt make it through the final selection

At the end you get a b-cell with amazing affinity for theantigendifferentiate into memory/plasma cells (plasma

cells secrete antibodies)

Spleen for foreign invaders of the blood streamknown as thelymph node for the entire blood stream

Dendritic cells: residents of the tissues, highly specialized antigenpresenting cells. Gobbling up, showing antigens and traveling to lymph

nodes. First responders Innate immunity Acute inflammatory response

Recruited by cytokines Immediate/Acute Not antigen Specific Control infection while special forces are mobilized Neutrophils:

Innate protection from bacteria and fungi Enzyme releasePath of destruction

Tissue destruction protective walling off Tissue destruction destroys circulation (could form abscess)

Acute inflammation Predominant Leukocyte

Eosinophil Innate protection from parasitic Infection Involved in allergic response (Eosinophil cause more harm than

health in our bodiesbecause we dont have parasites -- often

involved in allergic response.) Enzyme release


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Minor amount in blood (0-8%) Basophil

Not sure why we have basophiles Release histamines Hypersensitivity reaction

Very minor Leukocyte in blood (0-1%) Natural Killer Cells Innate response to viruses Antitumor activity Variable killer inhibitory receptors Cytotoxic granules release (like lymphocytes, but with granules)

Special forces Adaptive immunity know exactly which cell needs to be targetfor degradationtakes a little bit of time

B and T cells Adaptive Immunity Self vs. Non-Self Recognition

T cells: Targeting killing/cytokine release Intracellular Pathogens

B cells Antibody production, specific to antigen Tag pathogens for phagocytosis (by macrophages) Activate complement

Communication systemCytokines Weaponry/armsRadicals/NO/Enzymes

11-5-13 10AM Qualtieri Acute and Chronic Inflammation Lecture and CILS

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