Primary defence Barriers in Periodontal Pathogenesis (3) Adaptive Flashcards
What type of immunity do T cells provide?
cell-mediated
What type of immunity do B cells provide?
humoral
How are T cells activated?
APC
What interleukins cause T cells to proliferate?
IL-2,4,6
What is the process of Thelper cell activation?
When a an antigen-presenting cell activates a naïve helper T cell in a peripheral lymphoid tissue, the T cell can differentiate into either a TH1 or TH2 effector helper cell.
TH1 cells vs TH2 cells?
Th1 and Th2 cells play an important role in immunity.
Th1 cells stimulate cellular immune response, participate in the inhibition of macrophage activation and stimulate B cells to produce IgM, IgG1.
Th2 stimulates humoral immune response, promotes B cell proliferation and induces antibody production (IL-4).
What do CD4+ cells differentiate into?
memory
effector
What are the 3 types of effector T cells?
cytotoxic
lymphokine producing
helper/suppressor
What cell activates B cells to produce antibodies?
T helper cells
TH2
What is the initial Ab to be produced?
IgM
pentameric
What is the dimeric Ab? and its role?
IgA
defending mucosal surfaces against attack by infectious microorganisms
What is the Ab involved in a hypersensitive response?
IgE
What is the role of IgG?
Immunoglobin G (IgG) antibodies are produced seven to 14 days after infection, and are detectable for months and even years, depending upon the antigen and the individual
activate complement
What is the role of IgD?
appears to enhance mucosal homeostasis and immune surveillance by “arming” myeloid effector cells such as basophils and mast cells with IgD antibodies reactive against mucosal antigens, including commensal and pathogenic microbes.
What 2 factors dictate the damage bacteria cause to tissue?
quantity (local inflammation) and quality (virulence factors)
What 2 factors dictate the bacterial virulence?
bacterial load
bacterial composition
How does the host cause tissue damage?
Excessive host response can cause periodontal breakdown
Neutrophil recruitment leads to release of reactive oxygen species (free radicals) and enzymes that cause tissue damage
Host antioxidants can neutralise the free radicals, but they are not always enough.
What is an example of a free radical?
ROS
What periodontal tissues do free radicals effect?
bone
epithelium
connective tissue
What is the effect of free radicals on bone?
reduces osteoclast apoptosis
increased differentiation of osteoclasts
reduction in osteocytes
Bone reabsorption
What is the effect of free radicals on epithelium?
stimulation of Nf-kB and downstream production of pro-inflammatory cytokines
direct cell damage
recruitment and activation of neutrophils
apoptosis of endothelial cells
What effect do free radicals have on connective tissue?
direct tissue damage to fibroblasts
loss of connective tissue
What genetic factors increase host susceptibility?
Impaired neutrophil function
SCID
low IgA levels
defective bone and periodontal ligament
down syndrome
What environmental factors increase host susceptibility?
Smoking
Poorly controlled diabetes
Poor diet
medication
What local factors increase host susceptibility?
Plaque retention factors
