Myeloid Cells and the Innate Immune Response

Myeloid Cells

Subset of leukocytes in the innate immune system.

Granulocytes

Type of myeloid cells including neutrophils, eosinophils, basophils.

Neutrophils

Primary phagocytes in innate immune response.

Eosinophils

Combat multicellular parasites and allergic reactions.

Basophils

Release histamine in allergic responses.

Mast Cells

Release mediators like histamine during inflammation.

Monocytes

Circulate in blood, differentiate into macrophages.

Macrophages

Phagocytose pathogens and present antigens.

Dendritic Cells

Bridge innate and adaptive immunity, antigen presenting.

Pattern Recognition Receptors (PRRs)

Detect broad classes of pathogens, trigger immune response.

Toll-like Receptors (TLRs)

Recognize PAMPs, activate immune signaling pathways.

NOD-like Receptors (NLRs)

Intracellular sensors for detecting bacterial infections.

C-type Lectin Receptors (CLRs)

Bind carbohydrates, detect fungal components.

Pathogen-Associated Molecular Patterns (PAMPs)

Molecular patterns recognized by TLRs on pathogens.

NF𝚱B

Master transcription factor for inflammatory responses.

Inflammasome

Multi-protein complex activating inflammatory cytokines.

Phagocytosis

Uptake and destruction of pathogens by phagocytes.

Reactive Oxygen Species (ROS)

Toxic oxygen species produced during phagocyte activation.

NADPH Oxidase

Enzyme complex generating ROS in phagocytes.

Chronic Granulomatous Disease

NADPH oxidase deficiency leading to infection susceptibility.

Granuloma

Chronic inflammatory response to persistent infections.

Granuloma

Localized inflammatory response involving macrophages.

Multi-nucleated giant cell

Fused macrophages in chronic inflammation.

Anti-inflammatory drugs

Medications to reduce inflammation in patients.

Anti-fungal drugs

Medications targeting fungal infections.

Antimicrobial proteins

Proteins that directly combat pathogens.

Lysozyme

Enzyme in tears and saliva with antibacterial properties.

Defensins

Peptides secreted by phagocytes at mucosal sites.

Histatins

Proteins active against fungi in oral cavity.

Granulocytes

White blood cells containing inflammatory mediators.

Neutrophils

Type of granulocyte that engulfs pathogens.

Basophils

Granulocytes involved in allergic responses.

Eosinophils

Granulocytes that combat parasitic infections.

Mast cells

Cells releasing histamine during allergic reactions.

Mast cell degranulation

Release of mediators from mast cells.

Prostaglandins

Lipid mediators increasing vascular permeability.

Leukotrienes

Mediators attracting neutrophils and causing bronchoconstriction.

Platelet-Activating Factor (PAF)

Mediates bronchoconstriction and recruits eosinophils.

NETs

Neutrophil extracellular traps capturing pathogens.

C3 Convertase

Enzyme cleaving C3 into C3a and C3b.

Opsonization

Process enhancing phagocytosis of pathogens.

Membrane Attack Complex (MAC)

Complex forming pores in bacterial membranes.

Decay activating factor (DAF)

Prevents complement activation on self-cells.

Factor H

Regulates C3b cleavage to prevent self-damage.

Nisseria meningitidis

Pathogen that inactivates C3b to evade immune response.

Staphylococcus aureus

Bacterium inhibiting complement components.

Pathogen Entry

Initial access point for invading pathogens.

Pathogen Recognition

Identifying pathogens that breach physical barriers.

TLR

Toll-like receptors; recognize pathogens.

NLR

NOD-like receptors; detect intracellular pathogens.

CLR

C-type lectin receptors; bind carbohydrates on pathogens.

Phagocytosis

Process of engulfing and destroying pathogens.

Antimicrobial Proteins

Proteins that inhibit pathogen growth.

Granule Release

Discharge of cytotoxic substances to kill pathogens.

NETs

Neutrophil extracellular traps; trap and kill pathogens.

Complement MAC

Membrane Attack Complex; lyses pathogen membranes.

Inflammation

Response to infection; recruits immune cells.

NFkB Activation

Transcription factor activated by TLRs and NLRs.

Complement Pathway

Series of proteins aiding in pathogen elimination.

C3a

Anaphylatoxin; promotes inflammation and immune response.

CD18

Cell surface marker for leukocyte adhesion.

TLR4

Specific TLR that recognizes bacterial lipopolysaccharides.

C9

Component of the complement system; forms MAC.

C3b

Complement component that opsonizes pathogens.

Classical Pathway

Complement activation pathway triggered by antibodies.

Lectin Pathway

Complement pathway activated by lectin binding.

CCR1

Chemokine receptor aiding macrophage migration.

CCR5

Chemokine receptor involved in immune cell trafficking.

LFA-1

Integrin important for leukocyte adhesion and migration.