Cellular Immunity in Mice Chronically Exposed to Fresh Cigarette Smoke

Abstract
Mice were exposed daily to fresh cigarette smoke for up to 35 weeks. Cell-mediated immunity, as measured by the phytohemagglutinin (PHA) responsiveness of lymphocytes from various organs, was determined at different times during the exposure period. An initial enhancement was noted in the PHA responsiveness of lymphocytes from the regional lymph nodes of the respiratory system, but by the 35th week of exposure the response was markedly depressed. A similar depression was noted in lymphocytes from the blood.