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recovery of viable cells when preimmune serum from this rabbit was
employed as a control. When the cells surviving the rabbit antiserum
treatment were assayed for mitogen responsiveness, it was found that
the PIIA response was diminished and the LPS response was intact. Re
sults from two such experiments are presented in Table 7. These data
indicate that cytotoxic treatment of anterior kidney lymphocytes with
anti-brain plus complement may be an effective means of obtaining rela
tively pure LPS responsive cells and that this responsive population,
representing ^30% of the original population, may be a subpopulation of
lymphocytes in the bluegill.
Anterior kidney lymphocytes were tested with heterologous red blood
cells for spontaneous rosette formation. Results are presented in
Table 8. Only rabbit red blood cells were capable of rosetting a sig
nificant portion of the lymphocytes (> 20%).
To determine if the rosetted lymphocytes represented a discreet sub
population of the total with respect to mitogen responsiveness, rosetted
cells were depleted from the non-rosetted ones using Hypaque-Ficoll cen
trifugation. Seventy to 75% of the original number of lymphocytes were
recovered as non-rosette formers and were cultured under optimal mito
genic conditions. The results of two experiments are presented in Table
7. The LPS response was diminished while the PHA response was left intact.
These results indicate that depletion of lymphocytes rosetted with
rabbit red blood cells from non-rosetted lymphocytes may be an effective
means of isolating relatively pure PHA-responsive lymphocytes and that
this responsive population, representing 70-75% of the original popula
tion, may be a subpopulation of lymphocytes in the bluegill.