Oral Tolerance

Tolerance mechanism: Anergy

T-cells that react to food antigens don’t have co-stimulatory signals due to no inflammation. There is no signal 2 → anergy

Tolerance mechanism: Regulatory T-cells

Subset of T-cells downregulating T-cell responses. Mobile

Tolerance mechanism: Unique dendritic cells in the gut

Homeostatic something something promote Tregs

Which cytokines produced by T-regs are the anti-inflammatory ones

IL-10, TGF-beta

Natural Tregs

Induced in thymus during development

Control self reactive T-cells

Inducible Tregs

Induced in peripheral

Control tissue specific antigens and foreign antigens

What does the transcription factor FoxP3 do? - natural tregs

Hypothesized that T-reg precursors with this factor bind agonist peptides and develop into T-regs that help suppress activation to self-peptides

What influences inducible Tregs to be made?

DCs processing vitamin A and producing TGF-beta

What 4 major mechanisms due Tregs use to suppress cells?

1. Inhibitory cytokines

2. Cytolysis (granzyme b, perforin)

3. Metabolic disruption

4. Targeting dendritic cells

What signals BLOCK treg function?

IL-6

TLRs

Most innate pathways

What determines which type of T-helper cell will be active during a response?

The type of cytokines produced during an immune response

Can TH17 inhibit other T helpers?

Nope

How do the cytokines produced help determine which T helper is gonna be most active?

They regulate each other. A TH2 can inhibit a TH1, and vice versa. They do this using secreted cytokines