Innate Immunity (4)

Exam 2 MicroBio

Immediate defense reaction. NO memory of aggressors

Innate immunity

Slow defense reaction. Specific. Memory cells enabling vaccination

Adaptive immunity

____ immunity is essential for effective host defense at the early stage of infection

Innate

____ immunity is essential for microbe clearance

Adaptive

Steps of innate immune response (4 things)

• Recognition of the pathogen by host cells

• Recruitment of host cells at the site of infection

• Activation of destructive effector mechanisms

• Sentinel cells alert rest of immune that there is a danger

Which cells are accessible to soluble molecules & phagocytes?

Extracellular

Which cells require killing or activation of infected cells?

Intracellular

NK cells kill microbes where?

cytoplasmic; intracellular

Innate immunity recognizes what?

Many structures not present on normal host cells

PRR (Pattern Recognition Receptors) encoded in germline possess ____ diversity

Limited

Molecules expressed and/ or produced solely by microbes are called?

Pathogen Associated Molecular Patterns (PAMPs)

PRR expression and ligands are ____

Redundant

TLR4 will bind to _____

Lipopolysaccharide

Recruitment of what adaptor proteins leads to activation of transcription factors and cytokine production?

MyD88 and TRIF

___ recruits TRIF and triggers IFNa/B production

TLR3

___ (once it binds to LPS) recruit MyD88 and TRIF (adaptive proteins)

TLR4

(only receptor that recruits two)

NLRP3 Inflammasome assembly is initiated by ____ _____ molecules

sensing several

Inflammasome assembly leads to activation of what?

Capase-1 activation

Capase-1 activation results in?

Cleavage of pro-IL1B (inflam. cytokine) and Secretion of IL-1B

IL-1 B induces what?

Accumulation of neutrophils and monocytes at the site

Cell that is most abundant (1×10^11 / day) and is short lived (6 hours)

Neutrophils

Do neutrophils have lysosomes?

No

What mediates the earliest phase of inflammatory responses?

Neutrophils

What differentiates into macrophages in tissues?

Monocytes

What are the “second responders?” They are dominate effector cells that divide and persist at inflammation site

Macrophages

Function and activation of classical or M1 Macrophages

Trigger inflammation

Kill microbes

What cell type possess dendrites and phagocytic capabilities

Dendritic cells

Classical dendritic cells link ____ and ___ immune responses

innate and adaptive

Plasmacytoid Dendtric Cells produce what? Function?

Type 1 interferon (IFNalpha/B), possesses antiviral activity

Plasmacytoid DC bind to what?

dsRNA via TLR3

NK Cells produce what interferon?

IFNy

IFNy Function?

Activates macrophages that leads to the killing of phagocytosed microbes

How do NK cells kill virus infected cells?

via Perforin / granzyme

Activated Mast cells release proteolytic enzymes that contribute to what?

Inflammation, histamine, prostaglandin, heparin, leukotrienes, TNFa

Mast cell, basophil, and eosinophil are good in protecting against ___?

Helminth

What are the two signals lymphocyte activation requires?

• Signal 1: Antigen binding to antigen receptor

• Signal 2: Molecules provided by innate cells