Characterization of a cell population in thoracic duct lymph that adoptively transfers rejection of adult Trichinella spiralis to normal rats.

In Trichinella spiralis-infected rats, a population of cells in thoracic duct lymph (TDL) that can adoptively transfer protection to naive rats was identified and characterized. During the course of T. spiralis infection, blast cells appeared in lymph from Day 3-4, and only Day 3-4 TDL cells had protective properties after transfer. Protection was evident in a 1-2-day increase in the slow rejection of adult worms beginning 8-9 days after the challenge infection. The minimum number of TDL cells capable of transferring protection was 1.8 X 10(8) cells. Transferred cells could protect against a challenge infection with adult worms alone. A double cross-over experiment demonstrated that major histocompatibility complex identity was essential for effective transfer of protection (MHC restriction). An experiment using the mitotic inhibitor vinblastine showed that the protective cells belonged to a dividing cell population. The phenotype of the protective TDL was confirmed by a two-step cell separation procedure. First, it was demonstrated that surface Ig- cells (T cells) separated by affinity chromatography could transfer protection. Second, these surface Ig- cells were divided into two subpopulations by panning using monoclonal antibodies OX-8 and W3/25. The results showed that W3/25+ or OX-8- cells (T-helper) were effective in transferring protection. Protection was only seen when rats adoptively transferred with cells were challenged 1 day after cell transfer.