In vitro assessment of humoral immunity following exposure to heavy metals.

The immune system of animals and man is extremely complex. This report will discuss the effect metals has on one segment of the immune system; that is, humoral immunity. Humoral immunity is essentially the production of antibody in response to an antigen. The B-lymphocyte is the primary cell responsible for producing antibody. However, this cell is regulated by T-lymphocytes and macrophages. Many methods are available to assess humoral immune responses. A multitude of immunoassays have been developed for enumeration of serum antibody. Some of these are immunodiffusion, complement fixation, serum neutralization, hemagglutination, radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Detection of antibody-forming cells distinguishes between effect on antibody production compared to degradation of preformed antibody. Other available methods are measurement of surface receptor (Fc and complement) activity on B-cells. Mitogens (T-independent) have also been regarded as a measurement for humoral immunity. In our laboratory, we have developed an ELISA technique that is appropriate for general assessment of humoral immune responses resulting from chemical exposure. This technique is highly sensitive and can be mechanized. The assay can easily be incorporated into the drug and chemical efficacy testing programs of industry.