Lecture 1 - Overview of Immunology Flashcards
4 types of antigens? Examples for each.
- Pathogens: bacteria, viruses, fungi, parasites
- Molecules: proteins, polysaccharides, lipids, drugs, nucleic acids
- Transplanted organs or tissues
- Malignant cells
2 parts of the immune system? Describe each
- Central lymphoid tissue: source of immune cells => bone marrow and thymus
- Peripheral lymphoid tissue: site of antigen response => lymph nodes, spleen, tonsils, Peyer’s patches in gut, appendix, other mucosa such as the bronchial linings
Where does the transport of immune cells occur?
- Blood
2. Lymph
What is special about the role of the peripheral lymphoid tissue in the gut?
Needs to discriminate good nonself (food antigens and commensal bacteria) from bad nonself (pathogenic microorganisms)
Where is the family tree of immune cells rooted?
Bone marrow
What do white blood cells develop from?
Hematopoietic pluripotent stem cells in bone marrow
What are the 2 types of WBCs? Describe each.
- Lymphoid lineage => lymphocytes: T lymphocytes, B lymphocytes, natural killer cells, innate lymphoid cells
- Myeloid lineage => monocytes/macrophages/dendritic cells, granulocytes, mast cell precursors, erythrocytes, and megakaryocytes
Other name for granulocytes? Why?
Polymorphonuclear leukocytes because of their irregularly shaped nuclei
What are mononuclear leukocytes?
- Lymphocytes
2. Monocytes/macrophages/dendritic cells
How do lymphocytes learn to discriminate self from nonself? What is this called?
- Interaction of newly formed immune cells with other cells of the body
- Elimination of strongly binding autoreactive cells through death (deletion), anergy (made unresponsive), or suppression (held in check by regulatory cells)
- Surviving cells have no response to self => tolerant or “educated”
= EDUCATION
What are the 6 main types of immune cells and their function(s)?
- B lymphocytes => synthesize and secrete ag binding glycoproteins (antibodies)
- T lymphocytes => kill, help, regulate
- Natural killer cells => kill
- Dendritic cells and macrophages => take up and display antigens
- Neutrophils => phagocytosis
- Basophils, eosinophils, and mast cells => inflammation
How can we distinguish immune cells from each other?
- By their surface proteins: receptors for ags, signaling molecules, and adhesion molecules
- By their immune status
- By protein secretion
What are the 4 surface proteins of B lymphocytes?
- MHC
- Ig
- CD40
- BCR: B-cell receptor for antigen
What are the 4 surface proteins of T lymphocytes?
- TCR: T-cell receptor for antigen
- MHC
- CD4/8
- CD3
What are 3 types of T-lymphocytes based on their immune status? Describe each.
- Naïve T lymphocyte: prior to ag encounter, requires stronger signals to activate
- Activated, effector T lymphocyte: responding to ag
- Memory T lymphocyte: recognized ag in the past, activated more rapidly
How do immune cells communicate?
- Cell-cell interactions
2. Communication by soluble factors = cytokines
What is another name for cell-cell interactions between immune cells?
Receptor-ligand interactions
3 types of cell-cell interactions between immune cells? Provide an example for each.
- Antigen recognition: T Cell Receptor (TCR)—MHC molecule
- Adhesion: CD4/CD8—MHC
- Signaling: TCR—CD3
What is the role of the CD3 surface protein of T lymphocytes?
Help send antigen recognition signals to inside the T lymphocyte to activate it
What are cytokines? How do they work?
Hormone-like proteins secreted by a variety of cell types that bind cell surface receptors on a variety of cells to alter gene expression, causing:
- Differentiation
- Proliferation
- Activation/Inactivation
- Migration (chemokines)
What are 3 types of T-lymphocytes based on protein secretion?
- T helper 1: IFN-gamma
- T helper 2: IL-4
- T cytotoxic: perforin
Role of perforin?
Causes other cells to lyse