Delivery of Exogenous Antigens to Induce Cytotoxic CD8+ T Lymphocyte Responses

Table 1

Summary of the diverse vector approaches used for the generation of CTLs.

Vector	Outcome	Ref
VLP - Recombinant porcine parvovirus encoding LCMV-NP	- Strong CTL responses without a need for adjuvant, the CTL activity persisted in vivo for 8 months	[65]
	- Complete protection against lethal LCMV infection
VLP - HIV-p55gag-VLP	- Without adjuvant, long lived CTL responses against multiple HIV-1 p55gag epitopes were detected	[70]
VLP - Papaya mosaic VLP (LCMV-GP33)	- Immunized mice develop GP33-specific CTLs, which rapidly expanded post-LCMV challenge and enhanced the protection against LCMV infection in dose-dependent manner	[67]
VLP - HBV-VLP (LCMV-GP33)	- TAP-deficient DC and macrophages mediated cross-presentation of GP33 in vivo and in vitro	[69]
VLP- VSV encoding HPV-16 E7protein	- anti-E7 CD8+ T-cell response which conferred protection against E7 expressing tumor cells	[74]
Microsphere - Co-injected PPV-VLP	- Results in the priming of potent CTL responses in CD4 and CD40-independent manner	[80]
	- Protective CTL against the OVA-bearing melanoma
Microsphere - PLGA-MSs	- Vaccination enhanced CTL responses when OVA was coencapsulated with CpG or polyI:C	[84]
	- Single immunization with coencapsulated MS-OVA-CpG induced efficient CTLs and protected against infection with OVA-expressing vaccinia virus
	- Clonal expansion of primary and secondary antigen-specific CD4 and CD8 T cells	[60]
	- Potency demonstrated by protective immune responses to either infection or tumors
Liposomes -liposome-Ag-nucleic acid complexes (LANAC)	- TLR3 or TLR9 were able to enhance CTL cross-priming independent of CD4+ T-cell help	[56]
	- Antigen-specific CD8+ T cells were functionally active and persisted for long periods in tissues
	- Effective immunity against B16 tumors and M. tuberculosis
Archaeosome (M. smithii)- Encoding OVA	- Single injection evoked profound primary CTL response	[85]
	- Recall response observed >300 days
	- Protective CD8+ T cells induced in TLR2-deficient mice
	- Resisted tumor growth of B16OVA melanoma cells	[92]
	- Enhanced CTL responses in the absence of IL-12 and IFN-𝛾
	- CTL activity was undetectable in perforin-deficient mice	[93]
	- Long-term responses in CD4+ T cell deficient mice
	- Potent memory CTL response to OVA lasting for ≥154 days