parasites Flashcards
organism in which the parasite undergoes SEXUAL reproduction
definitive host
the organism in which the LARVAL or ASEXUAL stages of parasite lives
intermediate host
type of lesions that parasites can cause
destructive intraparenchymal lesions
types of mechanisms to escape host immune defenses
- masking
- blocking
- intracellularity
- antigenic variation
- immunosupression
- defense against complement
- defense against non-specific host responses
parasite has host Ig’s that they coat the surface with
masking
antibodies from the host bind to the parasite and prevent the cytotoxic antibodies from binding
blocking
live within the cells so the immune system doesnt catch them
intracellularity
change surface antigens each time there is humoral response or developmental stage
antigenic variation
- stimulate growth of non-specific antibody
- stimulate supressor T cells (inhibiting immune) or supressor factors
- antigen overload
immunosupression
-long surface proteins that bind complement but dont form membrane attack complex OR prevent complement cascade
defense against complement
parasite produces anti-oxidants to combat host attack
defense against non-specific host responses
combat intracellular organisms like protozoa
cell mediated immunity
th-1 subset and interferon gamma
combat parasites like intestinal worms
antibody immunity
th-2 (with Il-4 and Il-6)
primary cytotoxic effector cells
macrophages and eosinophils
antiparasitic immunoglobulin classes
IgM, IgG, IgE
