Liposomes as Vehicles for Vaccines: Induction of Humoral, Cellular, and MuscosalImmunity

摘要

Liposome research has been a major beneficiary of a recent resurgence of interestin vaccine adjuvants (reviewed by van Rooijen and Su, 1989; Gregoriadis, 1990; Alving 1991,1992; Phillips, 1992). Although liposomes were originally developed as models of efferent mechanisms exhibited by the immune response, it has now become evident that antigens that are presented or reconstituted in liposomes can provide desirable properties that promote effective humoral and cellular immune responses in many vaccines. Any substance that can increase the immunogenicity of an antigen has generally been considered to be an adjuvant, and hundreds of such substances have been proposed. The mechanisms of action of adjuvants and adjuvant formulations are frequently very complex and are also often poorly understood. Among many mechanisms that have been identified for different immunostimulating substances are the following: depot effect for slow release of antigen, binding or adsorption of antigen, targeting of antigen to antigen-presenting cells, reconstitution of antigen and presentation of T and B epitopes, reciuitment of immune cells, activation of complement, induction of cytokine production, and modulation of MHC class I or class II expression (Alving et al., 1992, 1993).