Download Immunity Ch. 11.1-6

Immunity Ch. 11.1-6
Microbiology
Immunology
Study of how the body
protects against and
responds to pathogens or
disease to keep you
healthy.
Overview of Immune System
• Protects against disease
(pathogens)
• Three Levels of Defense
1. Physical & Chemical barriersskin, mucous, flora
2. Innate-immediate non-specific,
inflammation, phagocytes
3. Adaptive (acquired)-slower,
develops over time, specific,
antibodies
11.1 Organs of the Immune System
• Thymus
• Spleen
• Tonsils
• Bone marrow
11.1 Tissues of the Immune System
• Lymph Vessels
• Lymph nodes
• Adenoids
• Skin
• Liver
11.1 Cells of the Immune System
Hematopoietic stem cells
• Innate Leukocytes
(white blood cells)
• Phagocytes
• Macrophages
• Neutrophils
• Dendritic cells
• Mast cells
• Eosinophils
• Basophils
• Natural killer (NK) cells
11.1 Cells of the Immune System
• Adaptive Leukocytes
(Lymphocytes)
• B cells-bone marrow
• T cells-thymus
1.1 Human-Microbial
Interactions
Human Microbiome Project
• Flora-Mutualistic both benefit or
Commensal-one benefits, other is not
harmed
• Skin-protection from pathogens
• Gut-vitamins, hormones,
protection, remove toxins &
immune system development
• Relatively few microbes are
pathogenic
11.2 Innate Immune Response
Natural Killer (NK) cells
• Recognize infected or
tumorigenic cells and kill
them.
• Major Histocompatibility
Complex (MHC) I molecules
• Release perforin which makes
the cells self-destruct
(apoptosis)
11.2 Physical & Chemical Barriers
• Skin
• Cilia-lungs
• Tears
• Mucus
• Sweat
• pH-stomach, vagina
11.2 The Complement System
• Around 20 soluble proteins
help destroy extracellular
microorganisms
• Produced by the liver &
macrophages
• Proteins bind to invaders
(non-self) (opsonization) to
identify them for destruction.
11.2 Pathogen Recognition
•
Pathogen-Associated molecular
Patterns (PAMPs)
•
Pattern-Recognition Receptors (PRRs)
1. Cytokines released, trigger
inflammation
2. Interferons warn nearby cells,
apoptosis
3. Interleukins help leukocytes
4. Phagocytosis
11.3 Phagocytosis
Engulfment of foreign material in the
body by a specialized cell
• Macrophages
• Dendritic cells
• Neutrophils
11.3 Antigen-presenting B & T cells
• Recognizes antigens derived from
pathogens.
• If you have a secondary infection
from the same or a similar pathogen,
memory B and T cells will give you
immunity.
• This natural process of creating
immunity is enhanced artificially by
the use of vaccines.
11.4 The Complement System
Three Biochemical Pathways:
1. Classical
2. Alternative
3. Lectin
Four Functions:
1. Opsonization
2. Chemotaxis
3. Lysis
4. Clumping
11.4 Innate Defenders
• Toll-Like Receptors (TLRs) recognize
molecules associated with pathogens
• Iron-Binding Proteins remove iron
from blood to limit pathogenic
growth.
• Antimicrobial peptides kill bacteria,
found on skin and in blood
11.5 Adaptive Immune Response
Humoral Response
• Defends against pathogens using
antibodies against pathogenspecific antigens.
• B & T cells
Differentiation
• Hematopoiesis (stem cells)
11.6 Antigens & Antibodies
Immunodeficiency
• Failure to respond, HIV/AIDS
Antibody Functions
1. Neutralization
2. Opsonization
3. Complement activation