EXPERIMENTAL HYPERSENSITIVITY PNEUMONITIS - LOCATION OF TRANSFERRING CELLS

Cultured cells from Micropolyspora faeni-sensitized donors can adoptiv ely transfer murine experimental hypersensitivity pneumonitis (EHP). W e sought to determine the location of transferred cells in recipient a nimals, the influence of the origin of the cultured cells, and the eff ect of specific intratracheal challenge. We labeled cultured sensitize d spleen or lung-associated lymph node (LALN) cells with CFDA-SE, a cy toplasmic stain, before transfer to naive recipients, which were sacri ficed 1 h, 1 day, or 4 days thereafter. We also transferred labeled cu ltured spleen cells to recipients that were challenged with intratrach eal M. faeni and sacrificed 4 days later (MF). Controls were recipient s of M. faeni-sensitized and cultured cells challenged with intratrach eal normal saline (NS) and recipients of ovalbumin (OVA)-sensitized ce lls cultured with M. faeni and challenged with intratracheal M. faeni (OVA). The number and proportion of cells that were stained were deter mined in dispersed spleen, peripheral and lung-associated lymph nodes, and lung parenchyma. The extent of the pulmonary inflammatory respons e was measured by determining the proportion of microscopic fields tha t were abnormal and the total number of dispersed pulmonary cells. CFD A-SE stained cells uniformly, and stained cells could be detected in r ecipients for up to 7 days after transfer. CFDA-SE treatment (0.5 mu M ) did not affect the ability of cells to transfer EHP adoptively. Tran sferred cells could be detected easily in lung, lung-associated and pe ripheral lymph nodes, blood, and spleen. Transferred cells localized t o the lung at 1 h but then rapidly decreased with no difference betwee n labeled cells from spleen and LALN. After intratracheal M. faeni cha llenge, there was no difference in the proportion of labeled cells in the lung among any of the groups (MF, NS, or OVA). There was an increa se in the number of lung cells in the MF group compared with the contr ol (NS and OVA) groups. We conclude that cells capable of transfer are transiently (1 h) trapped in the lung but are much decreased in the l ung by four days after transfer. After intratracheal antigen challenge of recipients, there is a substantial increase in the number of pulmo nary cells in animals exhibiting adoptive EHP but not in the control g roups. Transferred cells responsible for EHP are increased in the lung s of animals with adoptive EHP.