L1/L2: Intro to Immune System Flashcards
Antigens (Ag)
foreign material, bound by antibodies or lymphocytes
Antibodies (Ab; immunoglobulins)
Proteins that recognize/bind antigens very specifically
Cytokines:
low molecular weight proteins that are similar to hormones (Interleukins, interferons, etc.)
Histamine
a compound which is released by cells in response to injury and in allergic and inflammatory reactions, causing contraction of smooth muscle and dilation of capillaries.
Complement
system of proteins for defense against pathogens; some proteins are enzymes, others are involved in recognition/communication
Mucosa Associated Lymphoid Tissue (MALT)
present in surface mucosa of respiratory, gastro-intestinal, and genitourinary tracts
Gut Associated Lymphoid Tissue (GALT)
includes Peyer’s patches, appendix, solitary lymphoid nodules in submucosa
Lymphoid
T cells, B cells, NK cells (express Ag-specific Receptors)
Myeloid
Neutrophils, Basophils, Eosinophils, Monocytes, Macrophages, Dendritic cells, and Mast cells
Endocytosis
Engulfing macromolecules
• Nonspecific pinocytosis or specific,
receptor-mediated uptake
• Fusion with endosomes, then with lysosomes containing degradative enzymes
Phagocytosis
Engulfing whole cells/viral particles (intracellular killing)
• Can be used in either innate or acquired immune responses
Polymorpho- nuclear (PMN) leukocytes
granulocytes: Eosinophils, basophils, neutrophils
Short-lived; contain lysosomes; produce peroxide, nitric oxide, etc.
Macrophages
Large phagocytic cells that process and “present” antigens on the cell surface, to stimulate other immune system cells
Dendritic cells (DC)
Phagocytose, process, then “present” antigens on the cell surface, to stimulate other immune system cells
Natural Killer (NK) & Natural Killer T (NKT) cells
Cytotoxic functions; NK T cells also secrete cytokines
