General Overview of Immunology, Lecture notes of Immunology

Download General Overview of Immunology and more Lecture notes Immunology in PDF only on Docsity!

General Overview of ImmunologyGeneral Overview of Immunology

Kimberly S. Schluns, Ph.D.Associate ProfessorDepartment of ImmunologyUT MD Anderson Cancer Center

Objectives^ •^ Describe differences between innate andadaptive immune responses^ •^ Describe the immune cells that mediate andregulate immune responses^ •^ Define common terminology^ •^ Explain how immune cells recognize andrespond to foreign entities^ •^ Relate basic concepts of immunology to itsapplications in immunotherapy

Immune Reponses

Adaptive

Innate

• Always available • First line of defense • Specific for generaltypes of pathogens butnot an individualpathogen • Does not lead to lastingimmunity
  • Develops during lifetimeas an adaptation toinfections with pathogens • Is antigen specific (ex. H1N1 strain of flu but notall Influenza strains) • Confers long lastingimmunity

Function of Immune Reponses

• Immune Recognition-detects the presence of infection. • Immune Effector Function- contains and eliminateinfection (degradative enzymes, complement, Ab, celllysis) • Immune Regulation-controls immune response toprevent damage • Immunological Memory- protects against recurringdisease to the same pathogen^ All are accomplished by innate and adaptive immunecells except immunological memory

The myeloid lineage comprises most of the

cells of the innate immune system

Granulocytes

Short lived cells that possess granules containing degradativeenzymes and anti-microbial substances^ Neutrophils, Eosinophils, Basophils are sometimes referred to aspolymorphonuclear leukocytes:

Allergy

(Bloodmast cells)

Three Main Antigen Presenting Cells (APCs)

Immature DCsvery efficient atAg processing (in tissues)

Mature DCsvery efficient atAg presentation (in LNs)

Professional APCs present Ag to naïve T cells and induce activation

Lymphocytes Generally: small inactive cells

3 Types: T and B cells -mediate adaptiveresponses(recognize very specific antigensvia antigen-receptors) NK cells -mediate innateresponses(recognize generalfeatures on tumorand virus-infectedcells)

PAMP Receptors

are enriched on, but are not restricted to innate

Innate responses are initiated upon recognition of immune cells

common

features of pathogens (PAMPs) by pattern recognition receptors

PAMPs (Pathogen-associated moleculepatterns)-examples:lipopolysaccride onbacterial cell walls (LPS),unmethylated CpG DNA,mannose-richoligosaccarides

Infectious agents first activate innate immunecells resulting in an inflammatory responseCytokines-proteins that immune cells use to communicate/regulateother immune cells, not all cytokines are inflammatory Chemokines- group of cytokines that attract other immune cells

adaptivecellsarrivelater

DCs are important for initiating adaptive

immune responses

This is an important bridge between innate and adaptive responses;a failure to stimulate innate immune cells can lead to poor T cell and B cell responses.

Natural Killer Cells (NK cells) NK cells express inhibitory and activating receptors that recognizeself MHC class I and NK cell receptor ligands respectively

No NK cell activation Preformedgranules

/DC

CD8 MemoryCD8 T cell

MemoryCD4 T cell Memory

Adaptive Immune Responses

Antibodiespresent inblood allowimmunityto betransferredviaproteins

Immunityis mediatedby cells

Antigen Receptors

Antibody (Ab)

(Cell surface only)

(Cell surface and secreted)

T cell Receptor (TCR)