Lecture 4: Adaptive Immunity Flashcards
Hematopoietic stem cell
stem cell for all immune cells
produced in the bone marrow
These two cells are derived from hematopoietic stem cell
Myeloid Progenitor cell and Lymphoid Progenitor cell
What cell types are produced by the Myeloid Progenitor cell?
- RBC
- Platelet
- Neutrophil
- Eosinophil
- Basophil
- Monocyte- produce dendritic cell and macrophage
Monocyte can be further subdivided into:
Dendritic cell and Macrophage
Myeloid Progenitor cell produces cell types that are linked to what type of immunity?
Innate immunity
What are the cells produced by myeloid progenitor cell that are responsible for inflammation in innate immunity?
- Neutrophil
- Eosinophil
- Basophil
- Monocyte- dendritic cell and macrophage
Cell types produced by Lymphoid Progenitor cell
- Natural Killer cell
- T Lymphocytes
- B Lymphocyte
What cell type is produced by the Lymphoid Progenitor cell that plays a role in innate immunity?
Natural killer cell
What are the two cell types produced by the Lymphoid Progenitor cell that plays a role in adaptive immunity?
T Lymphocytes and B Lymphocyte
Examples of T Lymphocytes
- Helper cells
- Regulatory cells
- Cytotoxic cells
B Lymphocyte can further specialize into ________ cell which then generate ________
Plasma, Antibodies
Adaptive Immunity
Immune response mediated by B and T lymphocytes (B cell/T cell) to infectious agents and noninfectious molecules.
Difference of innate and adaptive immune response when it comes to detection?
Innate immunity- detects common microbial structures
Adaptive immunity- Detects vast repertoire of specific molecules on the pathogen
Difference of innate and adaptive immunity in terms of receptors?
Innate immunity- receptors are encoded in the germline. No recombination that occurs in the genome to create receptors.
Adaptive immunity- receptors generated by somatic recombination.
Difference of innate and adaptive immunity in terms of repeat exposure
Innate immunity- same magnitude of response upon repeat exposure.
Adaptive immunity- Improved “adapted” response to repeat exposure.
Adaptive immune responses are generated in response to “________”
Antigens
Antigen (Ag)
A “foreign” molecule, typically from a pathogen. Usually it’s foreign, but there are some that are not.
B cells recognize broad types of antigens. What are these antigens?
- Proteins
- Lipopolysaccharides
- Lipids
- Nucleic acids
T cells are highly specific when recognizing different types of antigens. What are the types of antigens recognized by T cells?
peptides (long peptides) derived from proteins
What are the critical mediators of the adaptive immune response?
B cells and T cells
Antigen presenting cells (APC)
T cells require antigen presentation by dedicated antigen presenting cells.
T cells don’t recognize antigen directly without some form of presentation.
Presents the antigen to the T cell receptor (TCR) of a T cell
How does the B cell detect antigen?
B Cell receptor (BCR) directly recognizes its cognate antigen.
B cells directly recognize the antigen through its BCR.
Two forms of adaptive immunity
- Humoral Immunity
- Cellular Immunity
Humoral Immunity
- directed against extracellular microbes.
- mediated by B lymphocytes
- B lymphocytes secrete antibodies that NEUTRALIZE and ELIMINATE microbes and microbial toxins.
- production and secretion of antibodies.
What happens in humoral immunity?
- Microbe binds to the B cell receptor (BCR) of the B cell.
- B cell gets activated
- Production of antibodies
Cellular Immunity
- directed against intracellular microbes.
- mediated by T lymphocytes
- T lymphocytes activate phagocytes and lymphocytes or kill infected host cells.
What happens in cellular immunity?
- T lymphocyte (T cell) receptor binds to the receptor of a host cell. Host cell has intracellular microbes
- T lymphocytes activate phagocytes and lymphocytes or kill infected host cells.
Why is it not enough to just rely on antibodies?
It’s not enough because some microbes might get inside the cells and not be found by antibodies.