12: Leukocyte Morphology, Kinetics, Functions

neutrophil band

what is this showing?

mature neutrophil

what is this showing?

when do primary granules appear?

late myeloblast/early promyelocyte stage

heterophils and what species has them?

similar to neutrophils, found in birds/reptiles

heterophils

what is this showing?

how to differentiate heterophils from eosinophils:

eosinophils are MUCH MORE GRANULATED

granulocyte/monocyte kinetics

randomly disappear from blood

lymphocyte kinectics

recirculate from tissues to blood

eosinophil kinetics

may return through lymphatics

monocyte kinetics

some may go back to bone marrow

neutrophil kinetics

survive a few days in tissue, will apoptosis randomly in stay in blood

marginating neutrophil pool

loosely attached to BV endothelium in small vessels/capillaries

high CNP, low MNP. diagnosis?

pseudoneutrophilia

% of lymphocytes in blood

2-5%

identity of most blood lymphocytes

naive T/B cells

what happens when lymphocytes recirculate?

bind to HEVS in lymphoid organs or activated endothelium in other tissues

HEVs

high endothelial cenules

describe lymphocyte recirculation

takes 10 hours -> memory leukocytes favor simple tissue -> proliferating cells DO NOT migrate far

how long do T-lymphs live?

years

how long do B-lymphs live?

2-3 weeks in cells, clones can live for years

how long do NK cells live?

2 weeks, constantly recirculating between blood/tissues

what can activate neutrophils?

opsonized material, immune complexes, bacteria, GM-CSF/G-CSF, chemoattractants

what OFFICIALLY activates neutrophils?

B2 integrin tightly binds to ICAMS

ICAMs

intracellular adhesion molecules

what do cells use to chemotax to area?

B1-3 integrin molecules

chemoattractants aiding in chemotaxis

IL-8, C5a, PAF, B4, bacterial products (LPS)

what helps with cell rolling?

selectins

what helps with cell adhesion/diapedesis/haptotaxis?

integrins

what does myeloperoxidase do?

converts H2O2 to HOCL (hydrogen peroxide to hypochlorus acid)

other enzymes used by neutrophils when killing

collagenase, acid/neutral hydrolases, lysozymes

what are the nonenzymatic proteins in a granule?

cationic proteins/peptides like defensins, lactoferrin

what do defensins do?

insert into lipid bilater

what does lactoferrin do?

binds iron

what are NETs?

neutrophil extracellular traps

what do NETs do?

bind/kill pathogens (bac/fungi/parasites/some viruses) WITHOUT phagocytosis

what does NETosis (special killing of neutrophil) require?

SUPEROXIDE FREE RADICALS

dog eosinophil

what is this showing?

cat eosinophil

what is this showing?

horse eosinophil

what is this showing?

describe eosinophils

little phagocytic ability, poor defense against bac/viruses

what does TH2 cytokine-induced inflammation produce?

type 1 HS ALLERGIC rxns

what is TH2 cytokine-induced inflammation used?

invasion of HELMINTHS (roundworms/flukes)

heartworm microfilaria

what is this showing?

what is used to kill helminths?

O2 metabolites, eosinophil catatonic proteins/neurotoxins (in granules)

dog basophil

what is this showing?

cat basophil

what is this showing?

cat mast cells

what is this showing?

origin of basophils AND mast cells

bone marrow

where do basophils mature?

bone marrow

where do mast cells mature?

in tissues

are mature basophils circulating?

YES

are mature mast cells circulating?

NO

do we see mature basophils in tissues?

NO

do we see mature mast cells in tissues?

YES

do mature basophils proliferate?

NO

do mature mast cells proliferate?

YES (limited)

how long do basophils live?

days

how long do mast cells live?

weeks-months

what gives granules a purple color?

histamine bound to polyanions (like heparin)

what do granules release following antigen-IgE binding?

histamine

MAIN functions of basophils/mast cells

EOSINOPHIL RECRUITMENT and explusion of parasites

equine monocyte

what is this showing?

dog monocyte

what is this showing?

monocyte function

phagocytosis

monocytes migrate into tissues and become what?

macrophages or inflammatory dendritic cells

true or false: chemoattractants of monocytes are SIMILAR to those of neutrophils

TRUE

function of M1 macrophages

antimicrobials (kill pathogens)

function of M2 macrophages

wound repair, tissue remodeling

in what infections are macrophages MORE EFFECTIVE?

viral/fungal/protozoal/helminth

in what infections are macrophages LESS EFFECTIVE?

bacterial

macrophage functions

antimicrobials, link innate/adaptive immunity, immune modulation

how are macrophages scavenger receptors?

by removing aged/damaged cells through necrophagocytosis, degrade iron stores for reutilization

lymphocytes with granules

cytotoxic T lymphs and NK cells

lymphocytes

what is this showing?

T-lymphocyte functions

cellular immunity

what do CD4/helper T cells do?

recruit/activate immune cells

what do CD8/cytotoxic T cells do?

antigen-dependent, destroy target cells

B lymphocyte functions

detect and bind antigens to receptor, produce Igs

what is the first Ig synthesized by B lymphs?

IgM

what is the second Ig synthesized by B lymphs if IgM doesn't get the job done?

IgG

plasma cells

what is this showing?

NK cell function

bind to tumor/virus cells, induce apoptosis

NK cell

what is this showing?