Biomedical Engineering Reference
In-Depth Information
5 Regulation of Immune Responses by Nanoparticle-Based
Vaccines
5.1
Induction of Immune Responses Using Amphiphilic
Poly(amino acid) Nanoparticles
Induction and regulation of an adaptive immune response by vaccination is possible
for a broad range of infectious diseases or cancers. Vaccine delivery and adjuvant
that can induce antigen-specific humoral and cellular immunity are useful for
development of effective vaccine systems. Cellular immunity is required to remove
intracellular pathogens, while humoral immunity plays a central role in neutralizing
extracellular microorganisms. The efficacy of antigen-loaded
g
-PGA-Phe
nanoparticles on the induction of antigen-specific humoral and cellular immune
responses was examined using OVA as a model antigen [
102
,
103
,
148
,
149
]. The
immune responses were investigated in mice after subcutaneous immunization with
OVA-NPs. The OVA-specific CTL responses were not observed in the spleen cells
obtained from the control (PBS) and OVA-alone-immunized mice. In contrast, the
spleen cells obtained from the mice immunized with OVA-NPs showed a more
potent CTL response than those obtained from mice immunized with OVA plus
complete Freund's adjuvant (OVA + CFA) (Fig.
15
). When anti-OVA antibody
responses were examined and compared among the groups after immunization,
both OVA-NP- and OVA + CFA-immunized mice showed significantly
higher levels of OVA-specific total IgG, IgG1, and IgG2a antibodies than OVA-
alone-immunized mice. These results indicate that the
g
-PGA-Phe nanoparticles
have the ability to prime cellular and humoral immunity by vaccination. It has been
Fig. 15 Induction of cellular immunity by subcutaneous immunization with OVA-encapsulating
g
-PGA-Phe nanoparticles. Mice were subcutaneously immunized one time with OVA alone
(10
m
g), 10
m
g of OVA and 100
m
g of NPs (
OVA-NPs
), 10
m
g of OVA and 100
m
L of complete
Freund's adjuvant (
OVA + CFA
), or PBS (control). Splenocytes were obtained from the
immunized mice on day 10 after the immunization and stimulated with the OVA peptide. The
number of IFN-
g
-producing cells was measured by enzyme-linked immunospot assay.
SFU
spot
forming units
