BIOMEDICAL APPLICATIONS III: DELIVERY OF IMMUNOSTIMULANTS AND VACCINES - Carbon Nanotubes: From Bench Chemistry to Promising Biomedical Applications - page 92

speciicity and antibody titers are important in ensuring the inal protective
result. Moreover, the groups of mice immunised with peptide alone or with
the peptide-CNT conjugate developed parasitaemia from day 7 onwards, but
they survived about 10 days longer than the mice of the control group (which
had much lower percentages of parasitaemia). These encouraging results
suggested that the groups treated with the peptide developed a late infection
and that the presence of CNTs did not hamper this phenomenon.
Finally, results obtained from cytokine proile analysis indicated
that the type of immune response induced by the peptide alone or by
peptide incorporated onto the CNTs occurred via Th1 cells, because of the
representative levels of TNF-α and IFN-γ displayed by these two groups of
immunised mice regarding the control, as shown in Figs. 5a and 5b.
Moreover, it is well known that there is an absolute requirement of IFN-γ
for protection against malaria in rodents, and it has been suggested that its
production may be a good correlation of protective immunity. 15

a

b

A

B

Post - challenge

Figure 4.5 Cytokine proiles of malarial challenged mice immunized with the 21267
peptide and its CNT conjugate. (a) Cytokine proile displayed by mice immunised with
the 21267 peptide. (b) Cytokine proile displayed by mice immunised with the CNT-
peptide 21267 complex. Reproduced from Yandara et al. 8 with permission.

4.3 INTERACTION OF FUNCTIONALISED CNTS WITH CpG
MOTIFS AND THEIR IMMUNOSTIMULATORY ACTIVITY

The presence of adjuvants is essential to promote and enhance immune
responses induced by vaccine antigens. One particular example of these
immunostimulants is represented by the synthetic oligodeoxynucleotides
(ODN) containing immunostimulatory CpG motifs (ODN- CpG), which have
envisaged their extensive use as immunomodulators against tumours or
allergies or even as protection against bioterrorist threats. 16-19 CpG motifs
are sequences deriving from bacterial DNA. Provided they are internalised
inside the cells in suficient amounts to interact with receptors (called toll-