immuno- L2: cells and lymphoid organs

adaptive

which type of immunity- innate or adaptive- can differentiate pathogens?

adaptive

are T and B cells related to innate or adaptive immunity?

mucous membranes

what is the primary barrier between the external world and internal body?

pluripotent stem cell

immune cells are all derived from what precursor cell?

bone marrow

immune cells originate in the _____

bone marrow

except T cells, which mature in the thymus

where do immune cells mature?

a cell capable of self renewing and converting into a different cell type

what is a stem cell?

1. environment (which organ)

2. exposure to cytokines and growth factors

what 2 factors influence the cell that the stem cells differentiate into?

the precursor of granulocytes, macrophages, dendritic cells, mast cells

what is a myeloid progenitor?

cells that recognize the pathogen- macrophages, dendritic cells, mast cells

what are sentinel cells?

pathogen-associated molecular patterns- molecules on the pathogens that serve as ligands for recognition molecules such as toll like receptors

what are PAMPS?

on sentinel cells (macrophages, mast cells, dendrites)

where are toll like receptors located?

recognize microbes via PAMPS and trigger inflammation, and have cytokines that can be released

what do toll like receptors do?

lipopolysaccharides (TLR4) and bacterial DNA (TLR9)

what are the 2 main types of toll like receptors?

monocytes

what is the immature form of macrophages?

immature macrophages

what are monocytes?

1/2 circulating the blood and 1/2 in the spleen

where are monocytes found?

monocytes

what is the largest leukocyte?

replenish macrophages.

in response in inflammation, they go to the site of infection and divide into macrophages and dendritic cells

what is the role of monocytes?

monocyte

a macrophage is a mature _______

2 days

how long can macrophages circulate in the blood?

innate

are macrophages involved in innate or adaptive immunity?

phagocytosis and antigen presentation

what is the role of macrophages?

chemokines

_____ direct macrophages

opsonized (coated with antibodies or complement)

in order for a macrophage to phagocytize, the pathogen has to be ______

microglial cells

macrophages in the brain are called...

macrophages in connective tissue

what are histiocytes?

alveolar macrophages or intravascular macrophages

what are the macrophages located in the lung called?

macrophages in the liver

what are Kupffer cells?

interleuken 1 (IL-1)

tumor necrosis factor (TNF)

what are the main cytokines secreted by macrophages?

promotes further growth and reproduction of lymphocytes

attract lymphocytes

what does interleukin 1 do?

mediates inflammation

attract neutrophils

what does tumor necrosis factor (TNF) do?

heat, swelling, pain, redness

an increase in TNF (tumor necrosis factor) causes....

controlling initiation in adaptive immunity

dendritic cells have a key roll in _______

process antigen and present it to T cells

act as a messenger between innate and adaptive immune system

what is the main function of dendritic cells?

yes

can dendritic cells identify the type of pathogen?

migrates towards a lymph node, so it can present it to T cells

once the dendritic cell engulfs the pathogen and displays it on the surface, what does it do?

major histocompatibility complexes (MHC)

antigen presenting cells have ______ on their surfaces

macrophages, dendritic cells, B lymphocytes

which are the antigen presenting cells?

cytotoxic T cells

APCs with MHC I present the antigen to _______

T helper cells

APCs with MHC II present the antigen to _______

it displays antigen peptides on its MCH

what occurs when the phagocyte ingests the antigen?

the T cell receptor

when the MHC has antigen peptides, it is presented to what part of the T cell?

the phagocyte secretes interleukins, which activate the T helper cell

when the MHC II with the antigen peptide and the T cell receptor bind, what happens?

T helper

MHC II is recognized by ________ cells

cytotoxic T cells

MHC I is recognized by ________ cells

secretes cytokines that stimulates it to proliferate, and binds to B cell in order to activate it

what does a T helper cell do when acitvated?

allows minding of the MHC II of the phagocyte and of the T helper cell

what does CD4 do?

B

T helper cells activate ______ cells

proliferates and differentiates into plasma cells/memory cells, which secrete antibodies

what does an activated B cell do?

when an activated T helper cell binds and secretes interleukins

how does a B cell become activated?

on the surface of all cells

where is MHC I?

cytotoxic T cells

MHC I is recognized by _______ cells

allows the cytotoxic T cell and MHC I to bind

what does CD8 do?

immune cells (dendritic cells, B cells, macrophages)

MHC II is on the surface of ______ cells

T helper cells and the MHC II of an immune cell

CD4 allows the binding of what 2 cells?

neutrophil

which is the most abundant leukocyte?

innate

is the neutrophil involved in the innate or adaptive immune system?

inflammation

in increased number of neutrophils indicates...

neutrophil

what cell is the first to arrive to an infection?

by chemotaxis

how do neutrophils migrate to the site of inflammation?

chemical signals that trigger a cell to move to a certain area (usually the site of infection)

what is chemotaxis?

kill invaders and then phagocytize the remains

what do neutrophils do?

no

are neutrophils antigen presenting?

bone marrow

when needed, neutrophils are rapidly released from________

eosinophils

which leukocyte is the main defense against parasitic infections?

they degranulate

once activated, what happens to eosinophils?

chemical mediators and proteins

what composes the granular contents of eosinophils?

inflammatory reactions- that cause allergic symptoms

basophils cause.....

IgE

the protein receptors on basophils can bind _____

basophils

which leukocyte has receptors on its surface that binds IgE?

small blood vessels

mast cells reside near...

release substances that affect vascular permeability (histamine)

when activated, what do mast cells do?

mast cells

what cell releases histamine?

basophil, eosinophil, mast cell

what 3 leukocytes are involved in allergy?

kill parasites

what do eosinophils do?

release histamines that dilate blood vessels

what do mast cells do?

mast cells

which cell triggers a local inflammatory response by releasing substances that act on blood vessels?

common lymphoid progenitor

what is the precursor of lymphocytes?

B cells

T cells

what are the 2 types of lymphocytes?

cytotoxic T cells

T helper cells

what are the 2 types of T cells?

kill virus infected cells

what do cytotoxic T cells do?

activate B cells

what do T helper cells do?

do not directly attack microorganisms, but attack infected cells and tumor cells

what do NK and NKT cells do?

NKT cells have both NK and T cell properties

NK cells do not have antigen specific receptors

what is the difference between NK cells and NKT cells?

innate

are NK cells innate or adaptive?

yes

do NK cells produce cytokines?

granulocyte

which is bigger, granulocyte or lymphocyte?

the CD-

CD3 is on all T cells (but not B cells)

CD4 is on T helper cells

CD8 is on cytotoxic T cells

what can be used to distinguish different cells?

major histocompatibility complex- the receptor for antigen presentation

what is MHC?

MHC I

which type of MHC is on all cells?

MHC II

which type of MHC is only on antigen presenting cells?

MHC

antigen presentation to TCR is mediated by _______

no

do MHC molecules discriminate between foreign and self peptides?

-stimulation of growth and proliferation of cytotoxic and suppressor T cells

-stimulation of B cell growth and differentiation to form plasma cells and antibodies

-activation of macrophages

what are the functions of lymphokines?

T helper cells

lymphokines are secreted by...

in the peripheral lymphoid organs- lymph nodes, spleen, mucosal lymphoid tissue

where do the antigen and lymphocytes encounter eachother?

APCs (antigen presenting cells)

antigens are carried to lymphocytes by...

regulate maturation of lymphocytes

what do primary lymphoid organs do?

no, only in the secondary lymphoid organs

do lymphocytes encounter antigens in the primary lymphoid organs?