Immune System Part III: Adaptive Immune System & Cell Mediated Immunity.
Study of the Immune System
description
Transcript of Study of the Immune System
![Page 1: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/1.jpg)
Study of the Immune System
![Page 2: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/2.jpg)
Now that we know all about microbes…..
What provokes us to fight against microbes? How do we know that they are foreign? What initiates the response?
![Page 3: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/3.jpg)
Introduction to Antigens Antigen (Ag)
Any substance that stimulates an immune response
Requirements for antigenicity foreignness (recognition of
nonself) large size complexity
most antigenic
![Page 4: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/4.jpg)
Characteristics of Antigens
Epitope antigenic determinant small molecular group that
is recognized by: Antibodies B cells T cells
![Page 5: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/5.jpg)
Defense Mechanisms of the Host Immune system
relies on a multilevel network of physical barriers, immunologically active cells, and a variety of chemicals
3 main lines of defense:
first line of defense any barrier that blocks invasion at the portal of entry nonspecific
second line of defense protective cells and fluids inflammation and phagocytosis nonspecific
third line of defense acquired with exposure to foreign substance Stronger immune response produces protective antibodies and creates memory cells specific
![Page 6: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/6.jpg)
![Page 7: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/7.jpg)
Physical or Anatomical Barriers: First Line of Defense
• Skin and mucous membranes: outermost layer of skin
few pathogens can penetrate if intact flushing effect of sweat glands mucous coat impedes attachment and
entry of bacteria blinking and tear production stomach acid nasal hair traps larger particles Vaginal secretions
![Page 8: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/8.jpg)
Structure and Function of the Organs of Defense and Immunity
Immunology study of the body’s second
and third lines of defense Functions of a healthy
functioning immune system:1. Constant surveillance of the
body2. Recognition of foreign
material3. Destruction of entities
deemed to be foreign
![Page 9: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/9.jpg)
Blood Plasma
Serum - fluid portion complement proteins and
antibodies Three types of formed elements
Erythrocytes Platelets Leukocytes
Divided into granulocytes and agranulocytes
![Page 10: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/10.jpg)
White Blood Cells White Blood Cells LeukocytesLeukocytes
Housekeeping and defenseHousekeeping and defense Scavenge dead or worn-out cellsScavenge dead or worn-out cells Disease organismsDisease organisms
Squeeze out of blood vessels and enter Squeeze out of blood vessels and enter tissuestissues
Develop from stem cells in bone marrowDevelop from stem cells in bone marrow GranulocytesGranulocytes
NeutrophilsNeutrophils EosinophilsEosinophils Basophils Basophils
Agranulocytes Agranulocytes MonocytesMonocytes Macrophages Macrophages
Lymphocytes Lymphocytes B-cellsB-cells T-cells T-cells
![Page 11: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/11.jpg)
White Blood Cells
Neutrophils 55-90% lobed nuclei with lavender granules phagocytes
Eosinophils 1-3% orange granules and bilobed nucleus destroy eukaryotic pathogens
Basophils, mast cells 0.5% constricted nuclei, dark blue granules release potent chemical mediators
Lymphocytes 20-35% large nucleus involved in specific immune responses
B (humoral immunity) T cells (cell-mediated immunity)
Monocytes, macrophages 3-7% large nucleus Phagocytic
Dendritic cells Activate lymphocytes Produce cytokines
![Page 12: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/12.jpg)
![Page 13: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/13.jpg)
Innate Immunity“Second” line of defense
![Page 14: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/14.jpg)
Second Line of Defense cells and mechanisms that defend the host
from infection by other organisms genetically-encoded to recognize:
common pathogenic features foreign substances
does not confer long-lasting or protective immunity to the host
provide immediate defense against infection
![Page 15: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/15.jpg)
Actions of the Second Line of Defense
• Recognition• Inflammation• Phagocytosis• Interferon• Complement
![Page 16: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/16.jpg)
1. Recognition Toll-like receptors (TLRs)
protein receptors within cell membrane of macrophages
recognize structurally conserved molecules derived from microbes
Detect foreign molecules and signal the macrophage to produce chemicals cytokines
stimulate an inflammatory response (nonspecific)
promote the activity of B and T cells (specific)
![Page 17: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/17.jpg)
2. Functions of inflammation
1. Mobilize and attract immune cells to site2. Set mechanisms to repair tissue damage3. Destroy microbes and block further invasion
![Page 18: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/18.jpg)
2. Inflammatory ResponseClassic signs and symptoms
characterized by: Redness
increased circulation and vasodilation in injured tissue
Warmth heat given off by the increased
blood flow Swelling
increased fluid escaping into the tissue as blood vessels dilate
edema WBC’s, microbes, debris and fluid
collect to form pus helps prevent spread of infection
Pain stimulation of nerve endings
Possible loss of function
![Page 19: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/19.jpg)
Fever Initiated by circulating pyrogens
cytokines produced by some leukocytes reset the hypothalamus to increase body temperature signals muscles to increase heat production and
vasoconstrict
Benefits of fever: inhibits multiplication of temperature-sensitive
microorganisms impedes nutrition of bacteria increases metabolism and stimulates immune reactions
![Page 20: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/20.jpg)
3. Phagocytosis
nonspecific defense mechanism
clear microbes from infected tissues
capture and digestion of foreign particles
![Page 21: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/21.jpg)
Phagocytes3 main types of phagocytes:
1. Neutrophils • general-purpose• react early to bacteria and other foreign materials,
and to damaged tissue2. Eosinophils
• attracted to sites of parasitic infections and antigen-antibody reactions
3. Macrophages • derived from monocytes• scavenge and process foreign substances to prepare
them for reactions with B and T lymphocytes
![Page 22: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/22.jpg)
4. Interferon Type of cytokine Produced in response
to viruses, RNA, immune products, and various antigens
Bind to cell surfaces and induce expression of antiviral proteins
Inhibit expression of cancer genes
![Page 23: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/23.jpg)
5. Complement (C) Consists of 26 blood proteins
proteins are activated work in concert to destroy
bacteria and viruses
![Page 24: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/24.jpg)
Adaptive Immunity“Third” line of defense
![Page 25: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/25.jpg)
Adaptive Line of Defense acquired immunity stronger immune response as well as
immunological memory Production of specific antibodies
dual system of B and T lymphocytes in response to an encounter with a foreign molecule
allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells
![Page 26: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/26.jpg)
Specific Immunity – Adaptive Line of Defense Two features that characterize specific
immunity: specificity
antibodies produced function only against the antigen that they were
produced in response to memory
lymphocytes are programmed to “recall” their first encounter with an antigen
respond rapidly to subsequent encounters
![Page 27: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/27.jpg)
Classifying Immunities Active immunity
person is challenged with antigen that stimulates production of antibodies
creates memory, takes time and is lasting Passive immunity
preformed antibodies are donated to an individual does not create memory, acts immediately, and is short
term Natural immunity
acquired as part of normal life experiences Artificial immunity
acquired through a medical procedure such as a vaccine
![Page 28: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/28.jpg)
Combinations of acquired immunity
Natural active immunity acquired upon infection and
recovery Natural passive immunity
acquired by a child through placenta and breast milk
Artificial active immunity acquired through inoculation
with a selected Ag Artificial passive immunity
administration of immune serum or globulin
![Page 29: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/29.jpg)
Development of the Immune Response System
Cell receptors or markers confer specificity and identity of a cell
Major functions of receptors are:1. perceive and attach to nonself or foreign
molecules2. promote the recognition of self molecules3. receive and transmit chemical messages
among other cells of the system4. aid in cellular development
![Page 30: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/30.jpg)
Acquired Immunity Generates Two Responses to Most Pathogens B lymphocytes
(B cells) involved in producing
antibodies against epitopes
Humoral immune response T lymphocytes
(T cells) provide resistance through
lysis of infected or abnormal cells
Cell-mediated immune response
![Page 31: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/31.jpg)
Lymphocyte Receptors Lymphocyte’s role in surveillance and
recognition is a function of their receptors B-cell receptors
bind free antigens T-cell receptors
bind processed antigens
![Page 32: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/32.jpg)
Antibody Structure and Functions Immunoglobulins Large Y-shaped protein Contains 2 identical fragments (Fab) with ends
that bind to specific antigen Fc binds to various cells and molecules of the
immune system
![Page 33: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/33.jpg)
Classes of Antibodies IgD
important in B cell activation IgM
released by plasma cells during the primary immune response
IgG crosses the placenta and confers passive immunity
IgA helps prevent attachment of pathogens to epithelial cell
surfaces IgE
causing histamine release when activated
![Page 34: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/34.jpg)
B-cell Activation and Antibody Production
Antibodies in Serum (Antiserum) The 1st introduction of an Ag to the immune system
produces a primary response gradual increase in Ab titer
The 2nd contact with the same Ag produces a secondary, or anamnestic, response due to memory cells produced during the initial
response
![Page 35: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/35.jpg)
T Cells & Cell Mediated Immunity Cell mediated immunity requires the direct
involvement of T lymphocytes T cells act directly against Ag and foreign cells when
presented in association with an MHC carrier T cells secrete cytokines that act on other cells Sensitized T cells proliferate into long-lasting memory
T cells
![Page 36: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/36.jpg)
Antibody-Antigen Interactions Opsonization
process of coating microorganisms or other particles with specific antibodies more readily recognized by phagocytes
Agglutination Ab aggregation cross-linking cells or particles into large clumps
Neutralization Abs fill the surface receptors on a virus or the active site on a
microbial enzyme prevent it from attaching
Antitoxins special type of Ab that neutralize a bacterial exotoxin
![Page 37: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/37.jpg)
Immunization Passive immunization
patient is given preformed antibodies form of immunotherapy
Active immunization patient is vaccinated with a microbe or its
antigens providing a form of advance protection
![Page 38: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/38.jpg)
Vaccines Type of active immunity Provide an antigenic stimulus
that does not cause disease Most vaccine preparations are
based on one of the following antigen preparations:1. Killed whole cells or inactivated
viruses2. Live, attenuated cells or viruses3. Antigenic molecules derived
from bacterial cells or viruses4. Genetically engineered
microbes or microbial antigens
![Page 39: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/39.jpg)
Disorders in Immunity
![Page 40: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/40.jpg)
Immunopathology Allergy, hypersensitivity
misdirected expression of immune responses to an allergen (antigen)
Autoimmunity abnormal responses to
self Ag Immunodeficiency
deficiency or loss of immunity
Four types…..
![Page 41: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/41.jpg)
Type Systems involved
Examples
I Immediate Hypersensitivity
IgEMast cells
Hay feverAsthma
II Antibody Mediated IgG AbIgM Ab
Blood group incompatability
III Immune Complex Mediated
IgGAb-mediated inflammation
ArthritisSerum sickness
IV T-cell Mediated Delayed hypersensitivity Cytotoxic rxns
Injection rxnsContact dermatitisGraft rxns
![Page 42: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/42.jpg)
1. Type I Hypersensitivity Two levels of severity:
Atopy any chronic local allergy Ex: hay fever or asthma
Anaphylaxis a systemic, often explosive reaction that involves
airway obstruction and circulatory collapse
![Page 43: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/43.jpg)
Contact With Allergens
Generalized predisposition to allergies is familial not to a specific allergy
Allergy can be affected by age, infection, and geographic area
Atopic allergies may be lifelong or may be “outgrown” may also develop later in life
![Page 44: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/44.jpg)
Mechanism of Type I AllergyDevelop in stages: Sensitizing dose
on first contact with allergen
specific B cells form IgE which attach to mast cells and basophils
generally no signs or symptoms
Provocative dose subsequent exposure with
the same allergen binds to the IgE-mast cell
complex
![Page 45: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/45.jpg)
Chemical Mediators and Allergic Symptoms
General targets include: skin, upper respiratory tract,
GI tract, and conjunctiva Responses
rashes, itching, redness, rhinitis, sneezing, diarrhea, shedding tears
Systemic targets smooth muscles, mucous
glands, and nervous tissue Responses
vascular dilation and constriction resulting in change in blood pressure and respiration
![Page 46: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/46.jpg)
Specific Diseases Atopic disease
hay fever, rhinitis; seasonal, inhaled plant pollen or mold
asthma Food allergy
intestinal portal can affect skin and respiratory tract
vomiting, diarrhea, abdominal pain possibly severe eczema, hives, rhinitis, asthma, occasionally
anaphylaxis Drug allergy
common side effect of treatment reaction from mild atopy to fatal anaphylaxis
Sudden respiratory and circulatory disruption that can be fatal in a few minutes
Bee stings, antibiotics or serum injection
![Page 47: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/47.jpg)
Treatment and Prevention General methods include:1. Avoiding allergen2. Use drugs
• block the action of the lymphocytes, mast cells
• antihistamines3. Desensitization
therapy • injected allergens
![Page 48: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/48.jpg)
2. Type II Hypersensitivity Involve antibodies and complement
leading to lysis of foreign cells Transfusion reactions
ABO blood groups Rh factor
hemolytic disease of the newborn
![Page 49: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/49.jpg)
Human ABO Antigens and Blood Types
Genetically determined RBC glycoproteins inherited as 2 alleles of A, B, or O
4 blood types: A, B, AB, or O type O persons lack both A and B
antigens Tissues other than RBCs also
carry A and B antigens
![Page 50: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/50.jpg)
Antibodies Against A and B Antigens Serum contains pre-formed antibodies
that react with blood of another antigenic type-agglutination
Type A contains Abs that react against B antigens
Type B contains Abs that react against A antigens
Type O contains Abs that react against A and B
antigens Type AB
contains no Abs that react against A or B antigens
![Page 51: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/51.jpg)
Rh Factor Rhesus factor RBC antigen
type results from combination of 2 alleles Either there or not
Rh- Rh+
Inheriting one dominant gene results in the production of the Rh antigen
![Page 52: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/52.jpg)
Rh Factor and Hemolytic Disease of the Newborn
Hemolytic Disease of the Newborn (HDN) Rh- mother forms antibodies to her
Rh+ fetus requires subsequent exposure to
the antigen to be hemolytic Prevention
use of passive immunization with antibodies against the Rh antigen
prevents sensitization of mother
![Page 53: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/53.jpg)
3. Type III Hypersensitivity Large quantity of foreign Ag
stimulates Ab produce small, soluble Ag-Ab
complexes Immune complexes become
trapped in tissues and incite a damaging inflammatory response arthus reaction
local reaction to series of injected Ag to same body site
serum sickness systemic disease resulting
from repeated injections of foreign proteins
![Page 54: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/54.jpg)
4. Type IV Hypersensitivity T cell-mediated Delayed response to Ag involving activation of and
damage by T cells Delayed allergic response
skin response to allergens tuberculin skin test, contact dermititis from plants, metals,
cosmetics Graft rejection
reaction of cytotoxic T cells directed against foreign cells of a grafted tissue MHC markers of donor tissue (graft) are different
host may reject graft; graft may reject host
![Page 55: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/55.jpg)
Immunodeficiency Diseases Components of the immune response system are absent
B and T cells, phagocytes, and complement 2 general categories:
primary immunodeficiency Congenital usually genetic errors T-cell or B-cell defect severe combined immunodeficiency (SCID)
secondary diseases acquired after birth caused by natural or artificial agents Chemotherapy AIDS
![Page 56: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/56.jpg)
Evasion of the Immune System by Pathogenic
Microorganisms
![Page 57: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/57.jpg)
Why develop a strategy for evasion?
Pathogen evolution Microorganism capable of causing disease Must subvert host immune system
Successful pathogens = effective evasion
![Page 58: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/58.jpg)
Defenses against human host responses Antiphagocytic factors
Glycocalyx / Capsules (Encapsulation) Host cell invasion
Grow intracellularly Neighbor cell transfer Syncytium Latency
Genetic changes Antigenic shift Antigenic drift
![Page 59: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/59.jpg)
Antiphagocytic Factors
![Page 60: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/60.jpg)
The Bacterial Surface Coating Glycocalyx
Coating of molecules external to the cell wall
Functions: attachment inhibits killing by WBCs
Talaro, 2008
![Page 61: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/61.jpg)
Capsules Formation correlates with pathogenicity Encapsulated cells protect against WBCs
Chemicals similar to those in human body Negative charges on capsule and
phagocyte surface Slippery
Pseudopodia cannot grip them
http://medicineworld.org/stories/lead/2-2009/how-a-deadly-fungus-evades-the-human-immune-system.html
Bauman, 2011
“Some Killers Have Pretty Nice Capsules”
S. pneumoniaeK. pneumoniaeH. influenzaeP. aeruginosaN. meningitidisC. neoformans
![Page 62: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/62.jpg)
Streptococcus pyogenes GAS Most serious
streptococcal pathogen
Many surface antigens that enable virulence and evasion
Talaro, 2008
![Page 63: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/63.jpg)
Capsule made of hyaluronic acid (HA)
Chemically masked from HA in human tissues
M-protein Makes surface projections that resist phagocytosis
C-carbohydrates Protect bacterium from being dissolved by lysozyme
C5a protease Catalyzes cleavage of C5a protein(hinders C-associated aspects & neutrophil response)
S. pyogenes…. “There’s an app for that”
![Page 64: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/64.jpg)
Host Cell Invasion
![Page 65: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/65.jpg)
Survive inside phagocytes after ingestion
Ingested by alveolar phagocytes Prevent fusion with
lysosomes Multiply intracellularly After cell death, attract
more phagocytes and continue cycle
Mycobacterium
Bauman, 2011
![Page 66: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/66.jpg)
Neighboring cell transfer
Can escape out of phagosomes
Transfer to neighbor cells w/o leaving host cell Not exposed to Ab
Listeria monocytogenes
Pommerville, 2007
![Page 67: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/67.jpg)
Syncytium
Induces cells to fuse Multinucleate giant cell Allows pathogen to move
from cell to cell HIV RSV Paramyxoviruses
Talaro, 2008
![Page 68: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/68.jpg)
Latency Pathogen remains
inactive for period of time
Reactivate at later date
Herpes
Bauman, 2011
![Page 69: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/69.jpg)
Genetic Changes
![Page 70: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/70.jpg)
Viruses
Glycoprotein spikes Adherence Recognized by host
immune system Influenza A & B
Contains two types of spikes
Hemagglutin (HA) Neuraminidase (NA)
Pommerville, 2007
![Page 71: Study of the Immune System](https://reader036.fdocuments.us/reader036/viewer/2022062315/56816093550346895dcfb9e5/html5/thumbnails/71.jpg)
Genetic changes of viruses Antigenic drift
Mutation in spikes Change their aa composition
Small changes Single strain
Antigenic shift Shift of gene strand with one
from another host Human, pig, birds, etc.
Abrupt, major change Reorganization of strains H1N1
Bauman, 2011