Serum from CBA/J mice made amyloidotic by chronic casein injections suppresses in vitro antibody response to SRBC. Similar suppression was also found with normal mouse serum but to a much lesser degree. This suppressive activity of both amyloidotic serum and normal serum was removed by absorption of the sera with antiserum to protein AA, the major constituent of casein induced (secondary) amyloid fibrils. The antiserum to the amyloid fibril protein AA (mol wt 8,400 daltons) detects an immunologically cross reacting serum alpha globulin (SAA) (mol wt approx. 100,000). It is postulated that the serum factor (SAA) is a regulator of antibody response and may be present in elevated amounts as the result of chronic antigenic stimulation.
ASJC Scopus subject areas
- Immunology and Allergy