c39 Flashcards
what is immunology
the ways in which our bodies fight off invading organisms and infection
cells, tissues and molecules involved in defending us
immune system
resistant to infection
immune (having immunity)
disease causing agents
pathogens
SARS-CoV-2 variants have changes in their __________ to better infect us and avoid our immune system
spike proteins
early method of inducing immunity to smallpox by deliberately exposing a person to material taken from smallpox sores of an infected individuals
variolation
the process of introducing a substance, such as a vaccine or pathogen, into the body to stimulate an immune response
inoculation
who provided first human vaccine in 1885 for Rabies
Louis Pasteur
fragment of pathogen
antigen
vaccines expose us to ______ or _______
non-lethal doses of pathogen
or
antigen (fragment of pathogen)
network of vessels with lymph (fluid derived from blood plasma)
lymphatic system
largest lymph vessel, drains into the bloodstream
thoracic duct
kill bacteria but also maintain good bacteria (commensal microbes) and prevent viral infection
defensins (alpha and beta)
all cells have what MHC (major histocompatibility complex) molecules
MHC 1
peptides are presented on what
MHC molecules (major histocompatibility complex molecules)
Professional antigen presenting cells (pAPCs) present what MHC molecule
BOTH actually
immune cells enter from the blood into lymph nodes via
HEV: high endothelial venule
embryonic stem cells are called
pluripotent which give rise to all cell types in the body
adult stem cells are called
multipotent which give rise to tissue-specific cell types
stem cells are found where
in the bone marrow
all our immune cells originate from a stem cell called…
Hematopoietic stem cell (HSC) or blood stem cell
what is hematopoiesis
maturation of HSC into immune cells
what are the primary lymphoid organs
bone marrow and thymus
specialized cells maintain the niche for immune cell development
stromal cells
HSCs (Hematopoietic stem cells) give rise to what
red blood cells (erythrocytes) and white blood cells (leukocytes)
leukocytes arise from what two progenitor cells
myeloid progenitor = myeloid cells
lymphoid progenitor = lymphocytes
myeloid progenitors/cells give rise to what part of the immune system
innate immune system
lymphoid progenitors give rise of what part of the immune system
adaptive immune system
myeloid progenitors give rise to what three things?
- leukocytes (white blood cells) in the innate immune system
- red blood cells/erythrocytes
- megakaryoctes and platelets for clotting
what are the 4 myeloid leukocytes/myeloid cells?
- monocytes: give rise to macrophages (and dendritic cells)
- granulocytes: give rise to eosinophils, basophils, neutrophils (and mast cells)
- mast cells
- dendritic cells
what kind of cells come from granulocytes (4)
- neutrophils
- Eosinophil
- basophil
- mast cell
myeloid –> granulocytes –> neutrophil, eosinophil, basophil and mast cell
granules are different for each cell type
contain proteins to harm pathogens, recruit immune cells or remodel tissue
temporary increase in neutrophil development
leukocytosis
what is the most abundant innate immune cell/leukocyte
neutrophils (50-70%)
- very short lived
-very mobile - increase very fast in number when there is an infection (leukocytosis)
- it is a phagocyte, but not very good, it eats pathogen and then dies
when neutrophils die/undergo apoptosis what do they do
create nets when they die, they explode contents in the extracellular area
also called NETosis = NETosis is a specialized form of programmed cell death in neutrophils that results in the release of neutrophil extracellular traps (NETs)—web-like structures composed of decondensed chromatin, histones, and antimicrobial proteins. These NETs trap and kill pathogens like bacteria, fungi, and viruses, helping to contain infections.
there is NETosis (slow cell death) and then Non-lytic NETOsis (rapid release from live cells) dont die here just spit
a type of myeloid cell and granulocyte that contributes to allergies and asthma
eosinophils, mast cells and basophils (both basophils and mast cells are non phagocytic)
who are the expert phagocytes (they don’t die after eating one thing
macrophages
macrophages are also known as
professional antigen presenting cells (pAPCs)
why does pus form at sites of infection?
neutrophils are present in large numbers at the infection site
what comprise the adaptive immune system
- T cells: differentiate into helper or cyototoxic (killer) T cells
- B cells: differentiate into plasma cells to secrete antibodies
also dendritic cells
every B cell has a unique B cell receptor (BCR) thats why we have really specific binding etc (respond to a multitude of pathogens)
yeah!
B cells are also pAPRcs like
macrophages and dendritic cells
what is the sole function of B cells
to make antibodies
what is the ligand (molecule that binds to a receptor) for T cell
major histocompatibility complex molecule (MHC) molecule
genes that encode MHC molecules are clustered in a chromosomal region called the
Major histocompatibility complex (MHC)
A membrane-bound glycoprotein comprising four immunoglobulin-like domains and closely resembling the single antigen-binding arm of an IgG molecule
T-cell receptor
we know that a TCR (T cell receptor) is composed of two different polypeptide chains of similar size but how many antigen-binding cites does it have?
only one antigen binding site
lymphoid progenitors give rise to what
- lymphocytes in the adaptive immune system: T cells and B cells
- innate lymphoid cells (ILCs)
what are the two cell types B cells can become once they have been activated/interacted with some pathogen
plasma cells: secrete antibodies
memory B cells: the cells that remember how to deal with an infection
B cells differentiate into what
plasma cells that secrete antibodies
what molecule is a helper T cell distinguished by
CD4
how can we identify immune cells
through CD molecules (ex. CD4 and CD8 on helper and cytotoxic cells)
cell to cell interactions are called what
(mix of receptors including CD molecules, integrins (adhesion molecules), MHC molecules and antigen receptors)
immunological synpase
ex. a dendritic cell and a T cell interacting
