Imunitas Pada Kulit
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Transcript of Imunitas Pada Kulit
Imunitas pada kulit
dr. Rohmania Setiarini
Pathogens(such as bacteria,fungi, and viruses)
INNATE IMMUNITY(all animals)
• Rapid response
Recognition of traits sharedby broad ranges ofpathogens, using a smallset of receptors
•
Recognition of traits specific to particularpathogens, using a vastarray of receptors
•
• Slower response
Barrier defenses:SkinMucous membranesSecretions
Internal defenses:Phagocytic cellsNatural killer cellsAntimicrobial proteinsInflammatory response
Humoral response:Antibodies defend againstinfection in body fluids.
Cell-mediated response:Cytotoxic cells defendagainst infection in body cells.
ADAPTIVE IMMUNITY(vertebrates only)
Immunity Innate & Adaptive
First line of defense
NonspecificRapid onsetNo protective
immunityNo memoryPhagocyte-
mediated
ActivatedVery specificSlowerProtective
immunity possible
Memory possible
Lymphocyte- mediated
Interval between exposures
First exposure
Second exposure
Time
Anti
bod
y C
once
ntr
ati
on
Section 40-2Immune Responses
Roles of the Skin
• The skin or integumentary system has four roles◦ It acts as a barrier against infection and injury◦ It helps to regulate body temperature◦ It removes waste products from the body◦ Provides protection against UV radiation from the
sun• It also serves as a way through which sensations
are transmitted to the nervous system
7
The immune system protects organisms
Most simply, 1. physical barriers prevent pathogens such as bacteria and viruses from entering the body
If a pathogen breaches these barriers, the 2. innate immune system provides an immediate, but non-specific response
If pathogens successfully evade the innate response, vertebrates possess a third layer of protection, the 3. adaptive immune system– Here, the immune system adapts its response during an infection to
improve its recognition of the pathogen– This improved response is then retained after the pathogen has been
eliminated, in the form of an immunological memory, and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered
Innate Immune Features of the Skin
Cells– Phagocytes: Macrophages, neutrophils, NK
cells– Mast cells
Circulating chemicals– Complement
Locally produced chemicals– Cytokines, histamine
Mast Cells Bone marrow-derived Dermal resident Perivascular Mediators
– Preformed (histamine, e.g.)– Newly synthesized (cytokines,
e.g.)
Cells of the Cutaneous Adaptive Immune Response
Langerhans’ cell Dermal dendrocytes Keratinocytes T-cells Endothelial cells
Langerhans’ Cells
Bone marrow-derived– Monocyte lineage
Transient epidermal cells Dendritic cell Electron microscopy: Birbeck granules,
convoluted nucleus
Langerhans’ Cells:Epidermal Transients
Migration and maturationBone marrow Blood Epidermis (LC)
Afferent lymph Lymph node Functions– Antigen capture and processing– Presentation of antigen– Costimulation of naïve T-cells– Produce activating cytokines
Langerhans’ Cell Migration
Antigen
Keratinocytes As Immune Cells
Old view: Keratinocytes... Are passive barrier cells Are passive victims of immune attack
Keratinocytes As Immune Cells
Newer view: Keratinocytes... Produce cytokines
– e.g., IL-1, TNF-, Chemokines Respond to cytokines
– e.g., IFN, IL-1 Upregulate ICAM-1 Present antigen Antimicrobial peptide
Endothelial Cells &Cutaneous Inflammation
Increase permeability When activated, endothelial cells...
– cell surface expression of P-selectin for enhanced leukocyte margination
– synthesis & expression of E-selectin for selective T-cell (CLA +) homing to the skin
– expression of VCAM-1 & ICAM-1 to stop leukocytes and allow diapedesis
Immune response amplified
Cutaneous Lymphocyte Antigen (CLA)
Specific skin homing marker on T-cells CLA+ lymphocytes are memory/effector cells
(CD45RO +) Cell adhesion to endothelial cell
– E-selectin is ligand With cutaneous inflammation, E-selectin up-
regulated, CLA+ cells selected
The Skin Immune System
Components1. APCs: Langerhans cells, dermal
dendrocytes, dermal macrophages2. Keratinocytes3. Endothelial cells4. Skin-homing T-cells5. Draining regional lymph vessels and nodes
Immune-response elements in non-inflamed skin.
Innate immune mechanisms in the skin
Adaptive immune responses in the skin
Immune-surveillance mechanisms in the skin