[Analysis of the regulation of IgG production to Cryptomeria japonica pollen antigen].

Genetic control of the immune response to Cryptomeria japonica pollen antigen (CPAg) in humans was analyzed using 72 unrelated healthy adults. The 72 were classified into a low responder group and a high responder group by using purified CPAg. Significant associations were found between IgG low responsiveness to purified CPAg and possession of HLA-DQw3. Relative risks for the two groups were 4.80. Peripheral blood lymphocytes from low responders revealed a specific IgG response to CPAg when the CD8+ T cell fraction was depleted. Thereby, low response due to the presence of CPAg-specific CD8+ suppressor T cells was suggested.