Humoral Immunity Flashcards
humoral immunity
defense against extracellular pathogens
mediated by B cells
plasma cells
produce antibodies in lymph tissues/organs
antibodies perform function at sites distant from production
effector function of antibodies?
neutralization, opsonization, and complement activation
neutralization
antibody binds to pathogen so it can’t gain entry to cell
sterically hinders the pathogens
**only requires binding to antigen
opsonization
microbe that is crosslinked with IgG
-phagocyte binds the Fc-gamma-RI receptors and activate it to ingest an kill pathogen
ADCC
antigen-dependent cellular cytotoxicity
NK binds to antibody-coated cells by Fc receptor and destroy these cells
mucosal immunity
IgA is secreted
**very important
neonatal immunity
antibody transport across the placenta and ingested in breast milk
IgG FcRn - transports across placenta
IgA in breat milk
what Abs for complement activation?
IgG and IgM
why is IgG so much more protective than IgM
IgM can only activate complement
IgG can activate phagocytosis and complement
-IgG also activates NK cells
CD19+ population?
B cells
CD3+ populaiton?
pan T cell marker
hyper IgM immunodeficiency
inability to class switch** aka HIGM
five genetic types
prone to bacterial and opportunistic infections
neutropenia, failure to thrive, thrombocytopenia, and anemia are common
X-linked HIGM?
defective CD40L expression
why are there antibodies to blood group antigens but not to tetanus toxoid antigens?
blood antigens - sugars
-t independent only produce IgM
tetanus - proteins
