| Tachyzoite to bradyzoite conversion |
Bradyzoite to tachyzoite conversion |
| High pHa |
Lack of NO |
| Low pHa |
Lack of IFN-γ |
| Heat shockb |
Lack of TNF-α |
| Mitochondrial inhibitionc |
Lack of IL-12 |
| Presence of NOc |
Lack of T cells |
| Elevation of both cAMP and cGMPd |
Induction of a variety of HSPs,including HSP70, is associated with bradyzoite transitione |
aOne cannot exclude that the differences in therapeutic efficacy between valproic
acid and sodium valproate used in several neuropsychiatric diseases were
related to acidic or alkaline target local tissue conditions induced by these two
pharmaceutical forms of a drug (low doses vs. high doses, respectively) [577,578].
bPhysiologically relevant circumstances that could play a role in stage conversion
in vivo include heat shock through a fever [576]. cNO overproduction in ASD
individuals [579] is an inhibitor of mitochondrial function [106]. dStress-induced
elevation of cAMP could play a role in bradyzoite induction because addition of
cAMP or cGMP to tachyzoites can stimulate stage conversion [580]. PLK, a T.
gondii ME49 clonal strain able to differentiate in vitro, exhibited a rise in cAMP in
response to bradyzoite inducing conditions, but elevation of cAMP under the same
conditions was not evident in RH, a strain that does not differentiate well [580]. It
must be emphasized that inducers of oxidative stress (nb. a state characteristic
for autistic patients) also have been demonstrated to cause parasite encystment
in vitro [581,582] |
