Innate and Adaptive Immunity Flashcards

Vocabulary flashcards based on lecture notes about Innate and Adaptive Immunity.

Innate Immunity

Fast response, typically within minutes post-infection. Recognizes stereotypical pathogen signatures (PAMPS). Always present.

Adaptive Immunity

Slower response; 2 weeks post 1st infection and 3 days after subsequent infection. Recognizes specific molecules that are specific to a pathogen. Requires gene arrangement.

Physical Barriers (Innate Immunity)

Skin (keratin & dead cells, low pH, salty), Respiratory system (ciliary escalator, coughing & sneezing, mucus), GI tract (peristalsis, lysozyme, gastric juice, anti-peristalsis 'vomiting', defecation, diarrhea), Eyes (teardrops, lysozyme), Ears (earwax), Urogenital tract (urine, vaginal secretion, low pH).

Neutrophil

Granular leukocyte; Polymorphonuclear (PMN) cell; First responder of infection; Phagocyte; 50-70% of WBC.

Eosinophil

Granular leukocyte; Less than 3% of WBC; Elevated count is a response to parasite infection or allergies; Secrete peroxide to kill parasites; Stain with acid-fast (Eosin dye).

Basophil

Granular leukocyte; Produces histamine as a response to allergy; Circulating in blood; Stained with methylene blue (basic dye).

Mast Cell

Granular leukocyte; Similar to basophil; Secretes histamine for allergy and inflammation; Fixed in tissue and does not circulate.

Dendritic Cell

Agranular leukocyte; Sentinel cells are professional Antigen-Presenting Cells (APC); Communicate between innate and adaptive immunity.

Macrophage

Agranular leukocyte; Monocyte turns into macrophage; Largest phagocyte; Professional APC; Eats in bulk.

Natural Killer (NK) Cell

Non-phagocytic; Active against cancer or viral-infected cells; Uses perforin & granzymes to kill.

Perforin

Creates channels in the target cells, causing them to burst (cytolysis).

Granzymes

Enzymes which digest protein inside the target cell, inducing apoptosis of that cell.

PAMPs

Pathogen-Associated Molecular Patterns; recognized by Innate immune system.

TLRs

Toll-like receptors; Membrane-bound receptors responsible for recognizing external PAMPs.

NLRs

NOD-like receptors; Cytoplasmic molecules that recognize intracellular PAMPs.

Membrane Attack Complex (MAC)

Pokes holes into a membrane, leading to cell lysis.

Interferons (IFNs)

IFN-α & IFN-β signal to neighboring cells about viral infections. IFN-γ signals macrophages to become more effective in combating bacterial infection.

Antimicrobial Peptides (AMPs)

Directly kill microbes, block cellular function, recruit immune cells, neutralize bacterial products, promote auto-inflammation; short chain of amino acids (between 12 to 50)

Defensin

Antimicrobial peptide that works by membrane rupture; produced by Epithelial cells

Cathelicidin

Antimicrobial peptide that causes membrane disruption. Secreted by: Keratinocytes.

Polymyxin B

Microbial AMP; Permeabilizes bacterial outer membrane.

Modulin

Microbial AMP; Produced by S. epidermidis to limit the growth of S. aureus & E. coli; causes bacterial lysis