At various intervals, from 10 minutes to 21 days, after the injection of dysentery bacilli into the hind foot pads of rabbits the popliteal lymph nodes were excised. The cells of the lymph nodes were teased free, washed, and injected intravenously into normal rabbits. In each case aliquots of the same cell suspension were either incubated at 37°C. for 24 hours or heated at 52°C. for 20 minutes and then injected into other normal rabbits, as controls.
In the case of lymph node cells obtained 4 or 3 days after the injection of antigen, antibody was found in the serum of recipients on the 1st day after the transfer of untreated cells. The titer increased until the 3rd day and then began to decline after the 5th or 7th day. In the sera of recipients of incubated cells antibody was not found, except on occasion after the 4th day and in low titer. This late appearance of antibody was attributed to the presence of small amounts of antigen in the original cell suspension.
As the interval between injection of antigen and collection of cells was increased beyond 4 days the effectiveness of the transfer decreased progressively until at 14 days no transfer effect was obtained.
When cells which were obtained 2 days after the injection of antigen were transferred, antibody appeared on the 2nd day after transfer and then followed the characteristic curve, whereas in the case of incubated cells antibody did not appear until the 3rd day after transfer. After the transfer of untreated 1 day cells antibody did not appear in the recipient until the 3rd day, and then followed the type of curve seen with 2, 3, and 4 day cells. Following transfer of incubated 1 day cells antibody also appeared on the 3rd day.
To establish the possibility of eliciting the cell transfer effect as early as 1 day after the injection of dysentery bacilli, recipient rabbits were x-irradiated 24 hours prior to the injection of cells. It was found that in the sera of such recipients of untreated cells antibody appeared on the 3rd day following transfer, while irradiated recipients of incubated cells did not develop any measurable amounts of agglutinin for the first 10 days.
It was concluded that a total of 3 days was required between the injection of antigen into the donor and the appearance of measurable antibody in the serum of the recipient, regardless of the fraction of that time spent by the cells in each of the animals involved, donor or recipient.
Following the transfer of untreated cells removed from lymph node as early as 10 minutes after the injection of antigen distal to them, antibody could be found in the sera of x-irradiated recipients 4 days later, whereas antibody did not appear following the transfer of heated cells to such recipients.