Immune Response Flashcards
what is the major reaction of innate immunity
inflammation
what are pathogen-associated molecular patterns
microbial structures recognized by receptors that are expressed by phagocytes, dendritic cells & others, shared among similar microbes
what is damage-associated molecular patterns
the substances released from injured & necrotic cells
cells that recognize these harmful molecules
pattern recognition receptors
what does adaptive immunity consist of
A. Humoral immunity; is mediated by Ab produced by B lymphocytes (Bc)
B. Cellular immunity = cell-mediated immunity is mediated by T lymphocytes (Tc
where do lymphocytes develop from
primary lymphoid organs
where do T and B lymphocytes cells develop
Tc → mature in the thymus
Bc →mature in the bone marrow
what are receptors for Bc and Tc
Antibodies
T Cell Receptors (TCR)
what are the secondary lymphoid organs
lymph nodes, spleen, mucosal lymphoid tissues
what is clone selection
when a specific antigen binds to the lymphocyte, activating the clones of those lymphocytes with the same antigen
Describe the action of
- Naïve lymphocytes
- Effector lymphocytes
- Memory lymphocytes
- express Ag receptors, but have not responded to Ag (no function)
- induced by lymphocyte activation. Perform the function that eliminate microbes
- ; induced during activation. Survive in a functionally silent state even after Ag is eliminated. Respond rapidly upon subsequent encounters with the Ag
what do T-lymphocytes help the B cells do
to produce Ab against protein Ag
Tc cells cannot recognize free circulating antigens but sense peptide fragments displayed by __________________
Major Histocompatibility Complex (MHC)
Tc can only recognize Ag presented by other cells
what are the types of T cells
(1-2.)CD4 & CD8 are expressed on distinct Tc subsets & act as co-receptors during Tc activation
- CD28 positive Tc- receptor for co-stimulators
- Regulatory Tc- suppress immune response
- Ƴδ Tc- recognize non-protein molecules e.g bacterial lipoglycans
- Natural killer c- express markers of both Tc & natural killer c
what are these T cells called, their function and what do they bind to
a) CD4
B) CD8
a) Helper Tc binding to MHC I, help Bc prod Ab
b) Cytotoxic Tc binding to MHC II, kill infected cell
what is (the major histocompatibility complex [MHC] in humans)
Human Leukocyte Antigen (HLA)
what mediates humoral immunity
B- lymphocytes
how do B lymphocytes recognize antigens
by means of membrane bound Ab of IgM class expressed on the cell surface together with signaling molecules =B-cell receptor complex (BCR)
what are the classes of Ig
IgA, IgG, IgM, IgE, IgD
what cells lack TCR
innate lymphocytic cells
what are the types of receptors on natural killer cells
Inhibitory rec. →recognize self-class I MHC on healthy cells Activating rec →recognize infected cells
what are the subsets of innate lymphocytic cells
TH1, TH2 and TH17
what do cytokines released by natural killer cells do
activate macrophages to destroy ingested microbes
what are the most important type of antigen presenting cells
dendritic cells
where are dendritic cells located
at the right place to capture Ag→under epithelia, interstitial tissue
what is an example of a dendritic cell
Langerhans cell in skin
dendritic cells have numerous _____________ and express many _________, high levels of ______ for Ag presentation
fine cytoplasmic processes
receptors
MHC
what is a major source of Interferon I
Plasmacytoid dendritic cell
what cells display Ag to Bc in lymphoid follicles
Follicular dendritic cells
what are other types of antigen presenting cells
- macrophages
* B cells
