1.
INNATE IMMUNITY
Our Non-Specific Defenses
References:
1. Immunology by Kuby
2. Microbiology by Tortora
3. Essentials of Immunology by Roitt
Marilen M. Parungao-Balolong

2.
WHAT YOU NEED TO KNOW
Differentiate innate from adaptive immunity
Define important terms related to innate
immunity
Be familiar with the 4 types of defense/
barriers in innate immunity
Be familiar with cells of the innate
immunity and their important roles

3.
Innate vs Adaptive Immunity
Susceptibility: Lack of Resistance to a Disease
Immunity: Ability to ward off disease
Innate immunity: Defenses against any pathogen
Adaptive immunity: Immunity, resistance to a specific
pathogen

4.
Recall: the Lymphatic System
Q: Why do you
think your lymph
nodes swell when
there is infection?

5.
4 Types of Defensive Barriers in Innate Immunity
Anatomic/Physical
Physiologic
Phagocytic
Inflammatory

6.
Anatomic: Skin
Serves as a Physical Barrier
Epidermis consists of tightly
packed cells with KERATIN, a
protective protein
Normal Microbiota:
Microbial antagonism/
competitive exclusion:
Normal microbiota
compete with pathogens

7.
Anatomic:
Mucous
Membranes
Ciliary escalator: Microbes
trapped in mucus are transported
away from the lungs
Lacrimal apparatus: Washes eye
Saliva: Washes microbes off
Urine: Flows out
Vaginal secretions: Flow out

8.
SUMMARY: Skin & Mucous
Membranes

9.
physiologic: low pH & Chemicals
Fungistatic fatty acid
in sebum
Low pH (3-5) of skin
Lysozyme in
perspiration, tears,
saliva, and tissue
fluids
Low pH (1.2-3.0) of
gastric juice
Transferrins in blood
find iron (Bind Serum
iron)
NO inhibits ATP
production

10.
Physiologic:
Temperature (FEVER)
Increased in Body Temperature
Hypothalamus normally set at 37°C
Gram-negative endotoxin cause
phagocytes to release interleukin–1
(IL–1)
Hypothalamus releases prostaglandins
that reset the hypothalamus to a high
temperature
Body increases rate of metabolism and
shivering which raise temperature
When IL–1 is eliminated, body
temperature falls (crisis)

11.
Physiologic:
Temperature (FEVER)
Advantages
Increase transferrins
Increase IL–1 activity
Disadvantages
Tachycardia
Acidosis
Dehydration

12.
Nice to
KNow:
Sickle Cell
Gene &
Malaria
Resistance

13.
Differential White
Cell Count
1. Neutrophils: Phagocytic
2. Basophils: Produce histamine
3. Eosinophils: Toxic to parasites and some
phagocytosis
4. Dendritic cells: Initiate adaptive immune
response
5. Monocytes: Phagocytic as mature
macrophages
a. Fixed macrophages in lungs, liver,
and bronchi
b. Wandering macrophages roam
tissues
6. Lymphocytes: Involved in specific
immunity

14.
To Be
Discussed
Fully in the
next Lecture :
Adaptive
Immunity

15.
phagocytosis
Phago: from Greek, meaning
eat
Cyte: from Greek, meaning cell
Ingestion of microbes or
particles by a cell,
performed by phagocytes

16.
Phagocytic
Barrier
*** PLay
Detailed Video

17.
Who Can Evade This
Process...

18.
Inflammatory
Barriers
Signs & Symptoms: Redness, Pain, Heat,
Swelling (edema)
Processes Involved
Acute-phase proteins activated (complement,
cytokine, and kinins)
Vasodilation (histamine, kinins, prostaglandins,
and leukotrienes)
Margination and emigration of WBCs
Tissue repair

19.
What are Released?

20.
Important Steps:
1. Tissue Damage
2. Vasodilation &
Increased Blood
Vessel
Permeability

21.
3. Migration
4. Tissue Repair
*** PLAY Detailed
Video

22.
the complement system
Serum proteins activated in a cascade *** PLay
Detailed Video

23.
alternative versus
classical
be Familiar with the
Similarities &
Differences...

24.
the lectin pathway

25.
Effects of Complement
Activation
Opsonization or
immune
adherence:
Enhanced
phagocytosis
Membrane attack
complex: Cytolysis
Attract phagocytes

26.
Some Bacteria Can Evade
This Process...
How?
Capsules Prevent C Activation
Surface lipid-carbohydrates prevent
MAC formation
Enzymatic digestion of C5a

27.
Interferons
Host-Cell Specific but not Virus Specific
SO HOW DOES IT STOP VIRUSES???
Alpha IFN and Beta IFN: Cause cells to produce antiviral
proteins that inhibit viral replication
Gamma IFN: Causes neutrophils and macrophages
to phagocytize bacteria

28.
Interferons

29.
To Summarize....

30.
NEXT MEETING:
ADAPTIVE OR
ACQUIRED
IMMUNITY