Biology Reference
In-Depth Information
6-sulphonic acid), Sigma Chemical Co., St. Louis, MO). Color was allowed to de-
velop for approximately 10 min at room temperature in the dark. The optical density
was measured at 405 nm using an ELISA reader (Multiskan Ex, Thermo Labsystems,
Finland). Antibody titers are represented as end-point dilutions exhibiting an optical
density of 0.3 units above background.
Statistical Analysis
Statistical analyses were carried out with the Prisma 4.0 Software (GraphPad, San
Diego, CA, USA). Group means were evaluated by ANOVA with Tukey's analysis to
compare individual groups. Values of
p
< 0.05 were considered significant.
CONCLUSION
Two sc immunizations with either ARC-
BM
/
GC
-BSA, plus a boost with BSA alone
rendered a long-term humoral response stronger than that achieved with BSA formu-
lated in alum.
Remarkably, our results were elicited in C3H/HeN mice, less prone to render po-
tent humoral responses than BALB/c and C57BL/6 backgrounds [43]. Such prelimi-
nary results merit deeper insights on the search of CD8
+
CTL activity and the induction
of this type of long-term memory upon sc immunization with ARC. As judged by
the phagosomal traffi c followed by the pair HPTS/DPX loaded in ARC, our results
indicated that there was neither fusion nor ARC content delivery to the cytoplasm,
for at least 60 min post ARC uptake. Hence, cytoplasmic delivery of hydrosoluble
material loaded in ARC-
BM
/
GC
should not happen, could either take longer than 60
min (considering that ARC-
BM
/
GC
were multilamellar, with negative zeta-potential
at physiological pH, both factors that impair or delay intermembrane fusion) or could
occur through mechanisms other than the fusion mechanism recently reported
for
Methanobrevibacter smithii
archaeosomes [47]. Finally, in spite of their TPL in-
variance, extreme halophilic archaea are source of glycolipid fractions that probably
markedly infl uence the induction of primary responses and memory recall [30]. In
view of that, the complete composition of ARC TPL and the mechanisms of recruit-
ment, uptake, and intracytoplasmic traffi c of this antigen-delivery system are currently
being analyzed in parallel with the ARC ability to induce expression of co-stimulatory
molecules on professional APC.
KEYWORDS
•
Archaeal lipids
•
Archaeosomes
•
Black mud
•
Electrospray ionization-mass spectrometry
•
Gray crystals
•
Halorubrum tebenquichense
•
Methanobrevibacter smithii
