defence cells

Question 1

what are the defence cells od myeloid origin?

Answer 1

neutrophils
macrophages
mast cells
eosinophils and basophils

Question 2

what is periodontitis?

Answer 2

chronic inflammatory disease
destruction of soft and hard tissues which support teeth
plaque build up-microbial dysbiosis
immune dysregulation plays a role

Question 3

what is the inflammatory infiltrate in diseased tissue composed of?

Answer 3

defence cells recruited to the tissue in response to microbial biofilm present on the tooth surface

Question 4

what are monocytes?

Answer 4

circulate in blood as precursors to macrophages-migrate into tissues and differentiate

Question 5

what are macrophages?

Answer 5

early responders to infection of tissue damage
long-loved, multiple functions
phagocytose and present antigen

Question 6

what are mast cells?

Answer 6

granulocytes
early responders to infection/tissue damage
migrate from blood and differentiate in tissues
protect against pathogens-role in allergy

Question 7

what are neutrophils?

Answer 7

phagocytic granulocytes
most + most important innate immune cells
circulate in blood and move into tissue when required
contain numerous granules

Question 8

what are basophils and eosinophils?

Answer 8

granulocytes
contain granules-degradative enzymes and antimicrobials
major role in defence against parasites as larger than neutrophils so can ingest larger threats
contribute to allergy

Question 9

what are dendritic cells?

Answer 9

myeloid and lymphoid lineage
main role=antigen presentation
move to tissues to lymph nodes passing on info
activate T and B cells

Question 10

describe memory generation in dendritic cells

Answer 10

immature DCs take up and process antigen in the epidermis
then migrate to lymph nodes and differentiate along the way
mature DC have co-stimulatory activity and can prime naïve T cells
can also transfer antigen to other DC resident in the lymph node

Question 11

what are NKC’s?

Answer 11

part of innate immunity(not myeloid)
large cells with granules
recognize and kill abnormal cells/tumour/viral infected cells
stall viruses until adaptive kicks in

Question 12

what are innate lymphoid cells? (ILCs)

Answer 12

non-cytotoxic members of the NK family
innate immune cell of lymphoid origin
link innate + adaptive
produce effectors (cytokines) similar to T cell subsets

Question 13

what are T cells?

Answer 13

derived in bone marrow, mature in thymus
circulate in blood and lymph and are found in large numbers in lymphoid organs
give rise to cellular immunity
protect against intracellular microbes and help B cell responses

Question 14

what do T Cell Receptors do?

Answer 14

recognise peptides presented by APCs

diversity - repertoire

Question 15

what are T helper cells?

Answer 15

CD4+
function to help support other immune cells to fight threats

Question 16

what are cytotocis T cells?

Answer 16

CD8+

destroy own cells which have become infected

Question 17

what are regulatory T cells?

Answer 17

Tregs-subset of CD4+

regulate or suppress other cells in the immune system

Question 18

what are the subsets of CD4+?

Answer 18

TH1-support macrophages
TH2-produce cytokines
TH17-secrete IL-17
TFH-induce B cell response
Treg-supress T cell activity

Question 19

describe memory generation in T cells?

Answer 19

once naïve T cell encounters presented antigen it undergoes expansion and differentiation into effector cells-short lived
small % become memory cells
activation->expansion->contraction->memory

Question 20

what are B cells?

Answer 20

communicate with T cells
specific receptor for antigens
produce antibodies
clonal expansion=generation of 2 subsets
plasma cells-antibody factories

Question 21

describe memory generation in B cells

Answer 21

interaction between T and B cell cytokine signals released from T helper cell to induce B cell proliferation
generates pool of plasma cells
plasma cells produce IgM and switch to IgG later