Dose response, prevention, and treatment of a transplantable lymphoid tumor

Transplantable lymphoid tumor (TLT) cells in doses ranging from 10(2.43) to 10(6.80) were transplanted into 3-week-old chicks. A total of 199 chicks in 31 dosage groups was included in this 2-year study. Overall mortality was nearly 100% and analysis of the results revealed no significant differences in mortality among the groups. A significant (P less than 0.001) linear relationship existed between log10 of the TLT cell dose and mean survival time. Serum obtained from chickens which survived TLT growth, regression, and challenge inoculation was administered to chicks 4, 7, or 11 days before TLT induction. Of the chickens in each of these 3 groups, 80 to 100% survived compared with 0 to 20% in those given control serum. In chicks with actively growing TLT that were treated with 2 injections of plasma from TLT-resistant chickens, mean survival time was lengthened and survival was increased by 36%. Lymphocytes from resistant chickens or plasma od and survival was increased by 36%. Lymphocytes from resistant chickens or plasma or lymphocytes from control chickens did not affect survival time or percentage of survival. In the present study, results demonstrated a similarity to the TLT model studied 30 years ago and established the usefulness of this model in the study of serum immunotherapy.