innate immune cells

neutrophils

First phagocytic responder by forming NETs

Wide range of pathogens

Granular

Yes

monocytes

Differentiate into macrophages and DCs

Wide range of pathogens

Agranular

Yes

macrophages

APCs, major phagocytic cell

Pathogens, necrotic tissues

Agranular

Yes

DC’s

Capture and present Ag to activate naive T-cells

Wide range of pathogens

Agranular

Yes

cDC1

CD8+ T-cells; cross presentation

cDC2

CD4+ T-cells

plasmacytoid

response to viruses, produce interferons (cytokine subtype) that help eliminate viruses

produce type I IFNs (antiviral)

In blood & some lymphoid organs

inflammatory DC

Monocyte derived DC - more likely to have inflammatory phenotype, derived from bone marrow. Once monocyte has reached tissue, it further differentiates based on environment signals it receives into a DC

anti-inflammatory

repair; derived from yolk sac progenitor 

tissue resident DC more likely involved in repair - same for macrophages and neutrophils

mast cells

Release histamines and have a high affinity for IgE Abs

Helminths, allergens

Granular

No

basophils

Histamine and also have receptor for IgE	Helminths, allergens	Granular	No

eosinophils

Enzymes against helminths and Igs receptors	Helminths	Granular	Yes

ILC’s

Activate macrophages, produce ILs and IFNs

Virus, bacteria, parasites

Agranular

No

ILC-1

• similar to T helper 1

• Release cytokines that deal w viruses (intracellular pathogens)

  • Activate macrophages

ILC-2

• similar to T helper 2

• Release cytokines that help w parasites (extracellular pathogen)

  • Aids in vasodilation & mucus release

ILC-3

• similar to T helper 17

• Release cytokines thats help w bacteria or fungi (other extracellular pathogens)

  • Also associated w mucosal protection 

  • Intestinal barrier & immune homeostasis

NK’s

Destroy malignant/ infected cells using perforin and granzymes

Malignant/ infected cells

Granular

No