Immunology 1 Flashcards
Which immune response is responsible for inflammation, complement activation, phagocytosis, and destruction of pathogen?
Innate immune response
Compare the typical time after infection for the start of immune response in the innate vs adaptive
innate is minutes vs adaptive which could be hours to days
How quickly does immunological memory take to begin?
days to weeks
Which immune response is responsible for interaction between antigen-presenting dendritic cells and antigen specific T cells and T cell proliferation and differentiation?
Adaptive immune response
What is considered to be the bridge between the innate and adaptive immune system?
Dendritic cells
What are the two major functions of macrophages?
APC
Phagocytosis
What cell is considered to be a “professional” APC? Explain their function.
Dendritic cells - uptake antigen in the periphery and present antigen to lymph nodes
What is 3 ways in which neutrophils clear pathogens?
Phagocytosis
NETs
Respiratory burst
Which cells are the 1st to respond in the innate immune system?
neutrophils
Which cells release histamine containing granules?
Mast cells
______ cells promote allergic response and augmentation of anti-parasitic immunity
Basophils
Which cells kill antibody-coated parasites?
eosinophils
What are Toll-like receptors responsible for on a macrophage?
sense pathogens and activate signaling pathways to induce immune and inflammatory genes
What do Toll-like receptors recognize?
patterns
What is the type 1 interferon response?
Anti-viral response - induce resistance to viral replication, increase MHC 1, activate dendritic cells, NK cells, and induce chemokines
What do mature dendritic cells activate?
naive T cells in lymphoid organs
Which cells present antigen to T cells?
B cells
While B cells can be activated independently, in most cases what do B cells need to be activated?
T cells
What occurs with antigen-receptor binding and costimulation of T cells by dendritic cells?
proliferation and differentiation of T cell to acquire effector function
What occurs with antigen-receptor binding and activation of B cells by T cells?
Proliferation and differentiation of B cells to acquire effector function
Being that the epitopes recognized by T cell receptors are often buried or embedded, what must happen?
Antigen first must be broken down into peptide fragments so that the epitope peptide can bind to a MHC molecule and both the MHC and epitope peptide complex can bind to TCR
Unlike TCRs which are embedded, where do BCRs recognize antigen
on the surface of the protein
Explain the function of ITAMs
highly conserved region in the cytoplasmic domain of signaling chains and receptors and is a critical mediator of intracellular signals.
What molecule is an important marker for T cell recognition and signaling?
CD3
Explain the structural difference between MHC class 1 and 2
The binding group on MHC 2 is bigger with an alpha and beta tail versus only the alpha tail in MHC 1
What is T cell proliferation mediated by?
cytokines
How is a naive T cell stimulated?
naive T cell must recognize a foreign peptide bound to a self MHC molecule. Simultaneously, a co-stimulatory signal by a specialized antigen-presenting cell must be delivered
Explain the impact of IL-2 on proliferation and the consequence of there being too much or too little
IL-2 is a necessary for recognition by the receptor (IL-2 receptor) for T cell proliferation. If there is too little proliferation will not occur and if there is too much the T cell will die
What are Th1 cells important for and what is an important molecule associated with them?
TH1 cells recognize complex of bacterial peptide with MHC II and activates macrophages - IFN-y is important
In general what are T helper cells important for?
recognition of complex of antigenic peptide with MHC II to activate B cells
What are the important molecules associated with TH2 cells?
IL-4,IL-5, IL-13
Which T helper cell is proinflammatory?
TH-17
What are TFH cells important for?
follicles mediate response that differentiates B cells
What do Treg cells do?
Silence CD4 or CD8 - anti-inflammatory
Which molecule is important for isotype switching and affinity maturation?
TFH cells
Explain the BCR complex
BCR complex consists of an antigen-binding subunit known as the membrane immunoglobulin which is composed of two immunoglobulin light chains and two immunoglobulin heavy chains as well as two heterodimer subunits of Ig-α and Ig-β with an ITAM region for cell signaling
In the BCR complex, why are the two heterodimer subunits Ig-a and Ig-b necessary?
There is a short cytoplasmic tail
Within the variable region of the heavy and light chains of the BCR, what is there that recognizes antigen?
hypervariable region
