What is "immunological tolerance"

Tolerance \Tol"er*ance\, n. [L. tolerantia: cf. F. tol['e]rance.]

1. The power or capacity of enduring; the act of enduring; endurance.

   Diogenes, one frosty morning, came into the market place, shaking, to show his tolerance.
   --Bacon.

2. The endurance of the presence or actions of objectionable persons, or of the expression of offensive opinions; toleration.

3. (Med.) The power possessed or acquired by some persons of bearing doses of medicine which in ordinary cases would prove injurious or fatal.

4. (Forestry) Capability of growth in more or less shade.

5. the allowed amount of variation from the standard or from exact conformity to the specified dimensions, weight, hardness, voltage etc., in various mechanical or electrical devices or operations; -- caklled also allowance specif.: (Coinage) The amount which coins, either singly or in lots, are legally allowed to vary above or below the standard of weight or fineness.

6. (Biochemistry) the capacity to resist the deleterious action of a chemical agent normally harmful to the organism; as, the acquired tolerance of bacteria to anitbiotics.

7. (Immunology) the acquired inability to respond with an immune reaction to an antigen to which the organism normally responds; -- called also immunotolerance, immunological tolerance, or immune tolerance. Such tolerance may be induced by exposing an animal to the antigen at a very early stage of life, prior to maturation of the immune system, or, in adults, by exposing the animal to repeated low doses of a weak protein antigen ( low-zone tolerance), or to a large amount of an antigen ( high-zone tolerance).

   Tolerance of the mint. (Coinage) Same as Remedy of the mint. See under Remedy.