Extracellular Bacteria 2a Flashcards
lecture 26-27
what recognizes invading extracellular antigens presented by macrophages and DCs?
CD4+ (antigens by MHC I and II)
CD8+ T cells (antigens by MHC I)
CD4+ polarized into Th1,2, 17 Tregs
between gram positive and negative bacteria, which one can MACs be established in?
gram negative, not in gram positive because there is no lipid bilayer
basic idea behind PRR recognition?
they can be located on the cell surface and intracellularly by TLRs
TLRs NLRs CDSs CLRs Scavenger receptors N-Formyl met-leu-phe receptors
what are some innate immunity reactions to extracellular bacteria?
defensins
complement pathway and opsonization (alternative, classical, lectin pathways)
MACs (negative gram bacteria, Neisseria)
what is the effect of antibody response to bacteria?
neutralization opsonization and Fc receptor mediated phagocytosis phagocytosis of C3b coated bacteria inflammation lysis of microbe
what are the effects of cytokine mediated antibody responses?
inflammation from IL-17, TNF, cytokines
macrophage activation to phagocytosis via IFN gamma
antibody response from other cytokines
what is the effect of the antibody on extracellular bacteria?
block penetration of microbe through epithelial lining
blocks binding of microbe and infection of cells
blocks binding of toxin to cell receptor
this type of infection contains viable microbes or microbial products in the blood?
sepsis
what are primary cytokine mediators of sepsis? what does this cause?
TNF, IL-6, and IL-1
systemic inflammatory response syndrome
what are some injurious effects of immune responses to extracellular bacteria?
cross reactive antibodies
rheumatic fever
carditis
immune complex deposition (nephritis)
this is when you have crossreactive antibodies to bacterial antigens with self antigens
immunopatholgy
pharyngeal infection
group A beta hemolytic strep
bacterial cell wall
M protein
rheumatic fever
what are the mechanism of immune evasion by extracellular bacteria?
resistance to phagocytosis
resistance to ROS in phagocytosis
resistance to complement activation
resistance to antimicrobial peptide biotics
this organism has resistance to phagocytosis
pneumococci
this organism has resistance to ROS in phagocytosis
staphylococci