Immunoenhancement

Allergy

Autoimmunity

Figure 1 Scheme for direct or Indirect effects of xenobiotic agents on the immune system and potential outcomes. (Reproduced with permission from Karrow JG and Holsapple MP (1995) Structure and function of the immune system. In: Smialowlcz R and Holsapple M (eds) Experimental Immunotoxicology, pp. 3-12. Boca Raton, FL: CRC Press.

established by examining sera for the presence of reagenic antibodies.

Historically, the guinea pig has also been used to test for potential skin sensitizers and such tests have been incorporated into many regulatory guidelines. Many variations in guinea pig hypersensitivity assays exist, but the Buehler occluded and Magnusson-Kligman maximization tests have been most often employed. Because guinea pigs are large, several graded doses of antigen may be tested and an entire dose-response curve can be generated by comparing skin reactions in individual animals. However, it is expensive to purchase as well as maintain guinea pigs, there are few inbred strains and immunological reagents are not widely available. As such, efforts are presently underway to replace guinea pig assays with mouse models. The most promising test is the local lymph node assay (LLNA). This procedure allows for the quantitation of lymphocyte proliferation in lymph nodes draining the site of chemical application, which is routinely the ear, and compared to guinea pig assays, is considerably less complex and time consuming. The LLNA may fail to detect some weak sensitizers and provide false positives for strong irritants, but modifications of the assay have been used, such as skin abrasion, to increase the

Table 1 Examples of agents reported to be immunotoxic

Hypersensitivity

Immunosuppression

Autoimmune-likea

Lung

Systemic

Drugs

Toluene diisocyanate

Dioxins, PCBs

Procainamide

Anhydrides

Organotin

Hydrazine

Wood dust

Alcohol

Isoniazid

Antibiotic dust

Marijuana

Halothane

Detergent enzymes

Heavy metals

Environmental

Skin

Lung

Vinyl chloride

Nickel

Asbestos

Trichloroethylene

Chromium

Silica

Cadmium

Certain pesticides

Ozone

Mercury

Animal products

no2

Foods

Citral

Skin

Alfalfa sprouts

Isoeugenol

Ultraviolet radiation

Tartrazene

Formaldehyde

Polycyclic

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


Post a comment