pubmed:abstractText |
After inoculation with viable BCG organisms, spleen cells from mice developed cellular immune reactivity to purified protein derivative antigen by day 10, which declined by day 25; after rechallenge on day 25, a vigorous secondary response rapidly developed (by day 29). The inclusion of autochthonous serum (from the BCG-infected mice) in the in vitro cellular immune reactivity tests altered this pattern considerably: the primary response was shortened, and the secondary response totally abated, suggesting the presence of blocking factors active against BCG-specific cellular immune reactivity in the sera of infected animals. Subsequent experiments indicated that BCG-specific serum blocking factor activity could be generated in the serum of control mice by the intravenous inoculation of purified protein derivative.
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