Tm. Work et al., Assessing humoral and cell-mediated immune response in Hawaiian green turtles, Chelonia mydas, VET IMMUNOL, 74(3-4), 2000, pp. 179-194
Seven immature green turtles, Chelonia mydas, captured from Kaneohe Bay on
the island of Oahu were used to evaluate methods for assessing their immune
response. Two turtles each were immunized intramuscularly with egg white l
ysozyme (EWL) in Freund's complete adjuvant, Gerbu, or ISA-70; a seventh tu
rtle was immunized with saline only and served as a control. Humoral immune
response was measured with an indirect enzyme linked immunosorbent assay (
ELISA). Cell-mediated immune response was measured using in vitro cell prol
iferation assays (CPA) using whole blood or peripheral blood mononuclear ce
lls (PBM) cultured with concanavalin A (ConA), phytohaemagglutinin (PHA), o
r soluble egg EWL antigen. All turtles, except for one immunized with Gerbu
and the control, produced a detectable humoral immune response by 6 weeks
which persisted for at least 14 weeks after a single immunization. All turt
les produced an anamnestic humoral immune response after secondary immuniza
tion. Antigen specific cell-mediated immune response in PBM was seen in all
turtles either after primary or secondary immunization, but it was not as
consistent as humoral immune response; antigen specific cell-mediated immun
e response in whole blood was rarely seen. Mononuclear cells had significan
tly higher stimulation indices than whole blood regardless of adjuvant, how
ever, results with whole blood had lower variability. Both Gerbu and ISA-70
appeared to potentiate the cell-mediated immune response when PBM or whole
blood were cultured with PHA. This is the first time cell proliferation as
says have been compared between whole blood and PBM for reptiles. This is a
lso the first demonstration of antigen specific cell-mediated response in r
eptiles. Cell proliferation assays allowed us to evaluate the cell-mediated
immune response of green turtles. However, CPA may be less reliable than E
LISA for detecting antigen specific immune response. Either of the three ad
juvants appears suitable to safely elicit a detectable immune response in g
reen turtles. (C) 2000 Elsevier Science B.V. All rights reserved.