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There was a discrepancy in the quantitation of surface immunoglobu
lin bearing cells by fluorescence (< 1%) or cytotoxic treatment (10-15%).
Such discrepancies are also seen in mammalian systems (90) and are prob
ably attributable to differences in sensitivities of the assays; cyto
toxic treatment is more sensitive since theoretically only two antibody
molecules (anti-immunoglobulins) combining with adjacent cell surface
immunoglobulin determinants should be necessary for complement mediated
lysis. Also, the failure to effectively deplete the LPS response with
anti-immunoglobulin plus complement in each experiment is an inherent
problem with mammalian systems and suggests that the alligator may also
have a subset of B-like cells which escape treatment and which may be
equivalent to a "null" cell in mammalian systems (94,105).
Fractionation of peripheral blood lymphocytes on glass wool columns
demonstrated an adherent lymphocyte population responsive to LPS. This
adherence is consistent with the characteristics of mammalian B-cells
since they are a more adherent cell than T-cells (2,54,110). However,
in order to explain the PHA responses routinely observed in the adherent
fractions, it is necessary to suggest that alligators have a subset of
T-like cells which are adherent to glass wool or alternatively a B-like
cell responsive to both LPS and PHA.
A small subset(s) of the lymphocytes with low stimulation indices
following LPS stimulation, low numbers of surface immunoglobulin bearing
cells, and low numbers of LPS-responsive cells adherent to glass wool
were found in the peripheral blood. Mammalian peripheral blood B-
lymphocytes also represent low percentages of the total number of
lymphocytes present in the circulation.