Tutorial 1 Flashcards
What is clonal selection?
Many antigen specific receptors are created with many different specificities on their surface.
When one of these diverse receptors comes into contact with respective antigen it replicates very quickly.
Immune response becomes tailored to the new antigen
What is memory?
Memory is the ability to create memory cells that respond more rapidly in secondary immune response due to presence of long-lived memory cells.
What are naïve lymphocytes?
Cells with receptors for antigens that have never encountered an antigen before.
What is the antibody response like in secondary response?
Much higher and more specific than the first response.
What is clonal expansion?
Increase in number of antigen-specific lymphocytes to keep pace with the microbes
What is contraction and homeostasis?
A decrease in number of immune cells to respond appropriately to the decrease in pathogens that were encountered. (i.e post disease recovery)
What is specialization?
Response is optimal for defence against different types of microbes.
What are the cells that initiate T cell response?
Dendritic cells
What is the effector phase of cell-mediated immunity?
Macrophages
What do follicular dendritic cells do?
Display antigens to B lymphocytes in humoral immune response
How are antigens eliminated?
T lymphocyte cytotoxicity
Monocytes and macrophages through phagocytosis
Granulocytes: neutrophils and eosinphils
What do helper T cells do?
They recognize pathogenic antigens and respond by releasing cytokines which stimulate activation of macrophages, inflammation, and activation of T and B lymphocytes
What do cytotoxic T lymphocytes do?
They recognize intracellular antigens by recognizing peptides bound to MHC molecules
What do regulatory T lymphocytes?
They limit activation of other lymphocytes especially T cells to prevent autoimmunity from occuring
What do NK cells do?
Recognize infected self cells and destroy them
Where do lymphocytes develop?
Common lymphoid precursors develop into mature forms in the bone marrow (for B cells) and thymus (for T cells)
What happens to naïve lymphocytes after interacting with foreign antigens?
Naïve lymphocytes recognize microbial antigens and differentiate and proliferate into effector lymphocytes after the appropriate additional signals are given to them
What do effector cells do?
Effector cells function to eliminate antigens. B cells are antibody secreting. CD4 lineage produce cytokines and CD8 cells are cytotoxic
What else do effector cells differentiate into?
Memory lymphocytes
Where do memory T cells migrate after differentiation?
Typically they are heterogenous with one subset that goes to lymph nodes, one subset to mucosa, and one subset to inflamed tissues
Where do effector lymphocytes go after differentiation and proliferation?
Inflamed tissues preferentially
Where do Naïve cells migrate after they are formed?
Peripheral lymph nodes
What types of antibodies are produced by Naïve cells?
IgM and IgD
What types of antibodies are produced by effector B cells?
IgG IgA and IgE
