Lecture 8 questions

Question 1

Acute inflammation or injury increases vascular permeability resulting in

Answer 1

redness, edema, and increased gingival crevicular fluid flow

Question 2

What are the two mechanisms for killing bacteria by neutrophils

Answer 2

oxidative and non-oxidative

Question 3

what does the oxidative mechanism for killing bacterial involve

Answer 3

reactive oxygen radicals and electron transfer reactions

Question 4

What does the non-oxidative mechanism for killing bacteria involve

Answer 4

enzymes that cleave

Question 5

how does a neutrophil protect the host

Answer 5

sends out cytoplasmic projections around bacteria creating a phagolysosome, which when completely surrounding the bacteria, is less damaging for the host

Question 6

what is the main difference between innate and adaptive/acquired immunity?

Answer 6

innate is based on inherent biological response, while adaptive/acquired is based on recognition of antigens, immune memory and clonal expansion

Question 7

what are the 3 major cells in chronic periodontitis?

Answer 7

plasma cells > b lymphocytes > t lymphocytes

Question 8

what do Th1 cells do?

Answer 8

interact with cancer cells or cells that have been infected

Question 9

what do Th2 cells do

Answer 9

produce antibodies

Question 10

what do b lymphocytes differentiate into

Answer 10

plasma cells, when acted upon by IL-10

Question 11

what compounds can serve as antigens?

Answer 11

LPS, bacterial proteins, etc

Question 12

what can function as antigen presenting cells (APC)

Answer 12

macrophages and langerhans cells

Question 13

what do the alpha and beta chains in T-cell receptors determine

Answer 13

the type of immune response

Question 14

what are the cytokines associated with Th1

Answer 14

IL-1, IFN-gamma, TFN-alpha

Question 15

what are the cytokines associated with Th2

Answer 15

IL-4, IL-5, IL-6, IL-10, IL-13

Question 16

how are Th1 and Th2 balanced

Answer 16

they are suppressed by IL-10 which has a general anti-inflammatory properties. a lot of IL-10 means that the are is pretty stable

Question 17

explain the t-cell response

Answer 17

Tc activated by cytokines -> Tc response to intracellular pathogens –> Tc recognize antigen presentation and destroy infected cells

Question 18

are there many Tc found in periodontitis

Answer 18

no, suggesting that viruses and invasive bacteria are not major players

Question 19

explain the b-cell response

Answer 19

Ab mediated humoral immunity triggered in response to soluble antigens -> Ag-Ab complex activated complement -> Ag-Ab complex facilitates opsonization -> Th2 activate B cells to plasma cells

Question 20

what are the 2 types of B cells

Answer 20

conventional: produce Ab against bacteria, they decrease in healthy or treated sites
auto reactive: produce auto-Ab, they don’t decrease after treatment

Question 21

explain Ab-medidated protection

Answer 21

Ab blocks entry of toxins/viruses (IgM, IgG, IgA) -> immobilizes bacteria (IgM>IgG) –> agglutinates bacteria (IgM, IgG)

Question 22

explain Ab plus complement-mediated protection

Answer 22

lysing bacteria (IgM, IgG)

Question 23

explain Ab plus cells-mediated protection

Answer 23

opsonizes bacteria/fungi for phagocytosis (IgG) -> activates extracellular killing (IgG)

Question 24

what is avidity?

Answer 24

Ag-binding differs among antibody subclasses, not all are capable of effective opsonization or complement activation

Question 25

how are IgG1 and IgG2 differ in periodontitis

Answer 25

IgG1 > IgG2 in chronic periodontitis but IgG1 < IgG2 in aggressive periodontitis

Question 26

explain antigen recognition in B-cell response

Answer 26

IgG2 recognizes LPS while other subclasses mainly recognize protein Ag

Question 27

what is the systemic humoral immune response to plaque antigens in the gingival crevice

Answer 27

1) plaque antigens diffuse through the junctional epithelium
2) langerhans cells within the epithelium capture and process the antigens
3) antigen-presenting cells (macrophages and langerhans cells) leave the gingiva in the lymphatics
4) antigen-presenting cells reach the lymph node and begin to stimulate lymphocytes to produce a specific immune response
5) periodontal microbe specific antibodies are produced any plasmas cells within the lymph nodes and travel back to the gingiva via blood vessels
6) antibodies leave the circulation and are carried to the crevice in the transudate from the inflamed and dilated blood vessels
7) antibody action on microbes in the crevice can result in killing, aggregation, precipitation, detoxification, opsonization and phagocytosis of bacteria

Question 28

what is the local cellular immune response to plaque antigens in the gingival crevice?

Answer 28

1) plaque antigens diffuse through the junctional epithelium
2) langerhans cells within the epithelium capture and process the antigens
3) antigen-presenting cells (macrophages and langerhans cells) leave the gingiva in the lymphatics
4) antigen-presenting cells reach the lymph node and begin to stimulate lymphocytes to produce a specific immune response
5) periodontally specific B cells (pre-plasma cells) and T cells proliferate within the lymph nodes and enter the blood stream
6) periodontally specific lymphocytes “home” back to the periodontist and locate within the tissues where they begin their humoral and cell-mediated immune functions
7) antibodies are produced located by plasma cells which are controlled by type 2 T-helper cells (TH2). cell-mediated immune activity is regulated by type 1 T-helper cells (TH1)

Question 29

Here are some other points we have to know

Answer 29

1) homing of relevant immune cells takes place in periodontal lesion
2) Th2>Th1 cells in chronic periodontal lesions
3) plasma cells are among the most predominate and active secretory cells in advanced periodontal lesions
4) the ratio of IgG subclasses are similar in serum and GCF
6) a person’s ability to mount a specific Ab response to bacteria in the subgingival biofilm may indicate a patient’s susceptibility to the disease and ability to respond to treatment