Experimental hypersensitivity pneumonitis in guinea pigs. Kinetics and dose response

Experimental hypersensitivity pneumonitis (HP) can be transferred by cells cultured in vitro with antigen, but not by noncultured cells. We determined the relationship between antigen concentration, time of culture, and development of competence to transfer HP and if separation of lymphoblasts from a noncultured cell population would allow transfer. We cultured lymph node cells from sensitized Strain II guinea pigs with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 48, 72, and 96 h, and isolated and transferred lymphoblasts intravenously to syngeneic recipients. Other animals received lymphoblasts from 72-h cultures exposed to 0, 0.1, 1, 10, or 30 micrograms/ml M. faeni. We also separated and transferred lymphoblasts from noncultured lymph node cell populations. Control animals received equal volumes of media. The animals were challenged intratracheally with M. faeni 48 h after the cell transfer, and they were killed 4 days after intratracheal challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media and a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymphoblasts cultured for 72 and 96 but not for 48 h. Recipients of lymphoblasts cultured for 72 h with 1, 10, and 30 but not zero and 0.1 micrograms/ml M. faeni exhibited increased extent of pulmonary abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)