A Review of Intra- and Extracellular Antigen Delivery Systems for Virus Vaccines of Finfish

Table 8

Comparison of the intra- and extracellular antigen processing parameters.

Parameters	Intracellular antigen delivery	Extracellular antigen delivery
Vaccine types
Viability of antigens	Mostly replicative	Nonreplicative
Examples of vaccine types	Live and DNA vaccines	IWV vaccines, subunit vaccines
Antigen uptake and presentation
Pathway of uptake into host cells	Endogenous pathway	Exogenous pathway
Antigen uptake and processing	Penetration of host cell membrane	Phagocytosis by APCs
Site of antigen deposition	Cytoplasm	Endosome/phagosome
Antigen presenting molecules	MHC-I and MHC-II	MHC-II
Mode of antigen processing	Proteosomal degradation	Endosomal degradation
Adaptive immunity
Type of immune response induced	Cellular and humoral immune responses	Humoral immune responses
Cell types involved	B- and T-lymphocytes	B-lymphocytes
T-cell subtypes	CD4 and CD8 T-cells	CD4 T-cells
Effector molecules/cells	CTL (cellular) and antibodies (humoral)	Antibodies
Effector mechanisms	CTL killing of virus infected cells	Antibody-neutralization of virus
	Antibody-neutralization of virus