Studies of the bluegill have shown that there are at least
two subpopulations of lymphocytes. One population was stimulated by
PHA (and Con A) at 32C and very poorly at 22C and was depleted by
antibrain plus complement treatment. The other population is LPS
responsive at both 32C and 22C, although responsiveness at 22C was
always greater and was depleted by removal of rabbit RBC rosetted
lymphocytes from the total population.
Temperature was also shown to be an important factor in in vitro
antigenic stimulations. In vitro SRBC primed cultures maintained at
32C elicited a very good plaque-forming cell response to SRBC's where
as 22C maintained cells gave no response. The temperature effects on
the in vitro cultures are discussed in reference to the reported in vivo
temperature effects on the teleost immune functions.
Evidence has been presented which argues for the presence of at
least two cell populations of lymphocytes in the alligator. Summarized
these are 1) differences in the magnitude of stimulation with the dif
ferent mitogens* 2) differences in the combined effects of the mitogens,
3) a significant increase in immunoglobulin producing cells in LPS-
stimulated cultures, 4) populations of cells adherent or nonadherent to
glass wool with different responses to LPS and PHA, 5) the depletion of
responsiveness to LPS by cytotoxic treatment with an anti-immunoglobulin
plus complement without reducing the responsiveness to PHA, and 6) the
depletion of responsiveness to LPS by removing immunoglobulin bearing
cells.
Environmental temperature was shown to effect the in vitro mitogenic
responses of cultured alligator lymphocytes. Although there were some
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