Lecture 1: Overview of Immune Responses Flashcards
An ____ (also called an antigenic determinant) is a portion of an Ag molecule to which an antibody binds
Epitope
The smallest epitope (antigenic determinant) to which an antibody can be made is about ___ amino acids or about ____ sugar residues
- 3-6 amino acids
- 5-6 sugar residues
T cell receptors recognize ___ amino acid sequences
linear
Antigens which can stimulate an immune response are also called ____
Immunogens (note all immunogens are antigens, but not all antigens are immunogens)
Some very small antigens called ____ can bind to Abs but they can’t initiate an immune response
Haptens
Innate immunity recognizes __ antigens belonging to groups of _____ microbes
common, related
What are the principle components of innate immunity
- Physical and chemical barriers
- Phagocytic cells, dendritic cells, and NK cells
- blood proteins (complement and other mediators of inflammation)
_____ is a system of plasma proteins that enhances the ability of Abs and phagocytic cells to clear pathogens form an organism
Complement
_______ are a large group of blood proteins whose plasma concentrations change in response to tissue injury, acute infections, burns, or inflammation
acute phase proteins (APPs)
A primary adaptive response normally takes
about a week
Each cytokine acts via a _____ expressed on targe cells
specific signaling receptor
Primary function of phagocytes (neutrophils and macrophages)
- To ingest and destroy microbes and get rid of damaged tissues (scavenger function)
Production of neutrophils is stimulated by cytokine called
Granulocyte colony-stimulating factor (G-CSF)
Neutrophils circulate in the blood for
hours or a few days
how long can neutrophils live after entering the tissues
1 to 2 days
Mast cells are common at sites in the body that are exposed to _______. They are also in close proximity to ______, why?
- external environment
- blood vessels, where they can reglate vascular permeability and effector-cell recruiment
Cells of the Macrophage lineage arise from committed precursor cells in the bone marrow, driven by
monocyte/macrophage colony-stimulating factor (M-CSF)
Dendritic cells can be broadly divide to _____ and ___ DCs
- myeloid (mDCs)
- plasmacytoid (pDCs)
Myeloid dendritic cells are derived from _____
monocytes
Antibodies recognize microbial antigens, and then ___ and ___ them
neutralize the infectivity of the microbes, and target microbes for elimination by various effector mechanisms
_____ immunity is conferred by a host response to a microbe or microbial antigen
Active immunity
What is the principle defense mechanims agains extracellular microbes and their toxins
humoral immunity (because secreted Abs can bind to these microbes and toxins and assist in their elimination)
_____ immunity is conferred by adoptive transfer of antibodies or lymphocytes specific for the microbe
passive immunity
