Autoimmunity Part 1 Flashcards
What are TLRs?
membrane bound receptors of the innate immune cells that recognize PAMPS. Activate NF-KB which increases cytokines and leukocytes causing inflammation and activates INF that stimulates antiviral cytokines
What is an NLR
A nod-like receptor that recognizes DAMPs and produce IL-1
Cell mediated immunity defends against _____ and is mediated by ______.
Intracellular pathogens; T cells
Humoral immunity defends against _______ and is mediated by ________
extracellular pathogens; B cells
What are the two type of antigen presenting cells?
macrophages and dendritic cells
An infiltrate of T cells expressing identical gene rearrangement of their T cells receptors are _____ and therefore represent_______.
clonal; a neoplastic population of malignant T cells
CD3 can be used to differentiate _______ cells
T cells
Which are more common CD4 or CD8 T cells? What is their function?
CD4 (60% vs 30%)–> secrete cytokines to help macrophages and B cells fight infection
Where is CD28 located?
on the T cell
What is the function of IL-2?
induces and sustains proliferation of activated T cells
What do TH1 cells secrete?
INF-gamma–> activates macrophages
stimulate B cells–> to secrete oposonizing and complement fixing antibodies (IgG)
What cells are involved in mediating delayed type hypersensivity?
TH1
What do TH2 cells secrete?
IL4–> induces synthesis of IgE from B cells
IL5–> results in activation of eosinophils
What do TH17 cells secrete?
IL-17–> recruit neutrophils and some monocyts
What is required for signal transduction following antigen binding in a B cell?
CD79
What are present on the surface of a naive developing B cell?
IgM and IgD
What are the 3 steps to B cell activation?
1) antigen must bind to antibody
2) CD21/CR2 on the B cell must bind to complement
3) CD40 on the T cell must be activated by T cells
What are 2 opsonizing agents?
IgG and C3b
What are the 2 types of dendritic cells?
1) interdigiting–> located in epithelial and interstitial tissues (Langerhan cells) and are important for initiating T Cell response via MHCII on initial encounter with the antigen
2) Follicular–> located in germinal center and are important for mediating ongoing immune responses (humoral immunity) by presenting antigens that have been opsonized to B cells
What are the targets of NK cells?
viruses and tumors
CD16 is located on which cells?
NK cells; it binds to IgG
What are the two ways NK cells target cells for lysis?
1) Antibody dependent cell mediated cytotoxicity (CD16 binds IgG)
2) Monitoring MHC class I and stress molecules
What are the 5 functional classes of cytokines (ILs)?
1) mediate innate immunity
2) regulate lymphocytes
3) activate inflammatory cells
4) chemokines (affecting lymphocyte movement)
5) stimulate hematopoiesis
What is the function of IL-12?
It induces cells to differentiate along the TH1 pathway
