Antibody production by lymph-borne immunoblasts following subcutaneous injection into xenogeneic recipients.

Efferent lymph was collected from individual lymph nodes of unanaesthetized sheep following stimulation of the nodes with a variety of antigens. At the height of the immune responses (i.e. 80–120 hours after stimulation) 15–30 per cent of the lymph cells were large, basophilic immunoblasts. Lymph cells collected during these times were washed and injected subcutaneously into small laboratory rodents (usually C57 black mice); each recipient received a single injection of lymph cells containing 1–2 × 10 immunoblasts. Between 24 and 100 hours later the recipients were killed and exsanguinated. By the latter time substantial titres of specific agglutinating or lytic antibodies were demonstrable in the sera of the recipients and immunodiffusion and immunoelectrophoresis studies confirmed the presence in these sera of sheep immunoglobulins. Only trivial titres of antibody appeared in the recipients' sera when lysed lymph cells had been injected and no antibody or immunoglobulin was detectable following the injection of normal small lymphocytes from unstimulated or hyperimmune sheep. An autoradiographic, electron microscope study showed that although many of the injected immunoblasts degenerated rapidly a significant proportion survived long enough to develop lamellar endoplasmic reticulum. It was concluded that some of the injected cells survived long enough to synthesize and secrete specific antibody; on the basis of mercaptoethanol sensitivity it was concluded that both 19 and 7S antibodies were produced. When sheep immunoblasts were injected subcutaneously into isogeneic or allogeneic sheep specific antibody appeared in the local tissue fluid and reached a relatively high titre some 50 hours after the injection.