Type II NKT cells facilitate Alum-sensing and humoral immunity.
ABSTRACT Alum-based adjuvants facilitate vaccine-driven humoral immunity, but their mechanism of action remains poorly understood. Herein, we report that lack of type II NKT cells is associated with intact, mature B cells but dampened humoral immunity following immunization with Alum-adsorbed T-dependent antigen. Type II NKT cells facilitated production of IL-4, IL-5, IL-10, IL-13, and antibody by LN and splenocyte cultures following Alum/antigen administration in vivo and antigen restimulation in vitro. Addition of IL-4 and IL-5 to type II NKT-deficient cultures restored in vitro antibody production. Intracellular staining revealed that Alum-primed type II NKT cells coordinated IL-4 secretion by T cells. Alum did not significantly affect CD1d expression in vivo, but addition of CD1d-blocking mAb diminished cytokine production and in vitro antibody production. Type II NKT cells therefore function as part of the Alum-sensing apparatus and in a CD1d-dependent manner, facilitate T(H)2-driven humoral immunity. This may have important consequences for understanding the mechanism of action of Alum-containing vaccines.
- SourceAvailable from: europepmc.org[Show abstract] [Hide abstract]
ABSTRACT: Particulates and crystals stimulate the immune system to induce inflammatory responses. Several nanometer- to micrometer-sized particulates, such as particle matter 2.5 (PM2.5), diesel particles, and sand dust, induce pulmonary inflammation and allergic asthma. Conversely, nanometer- to micrometer-sized crystal, sphere, and hydrogel forms of aluminum salts (referred to as "alum") have been used as vaccine adjuvants to enhance antibody responses in animals and humans. Although most of these particulates induce type-2 immune responses in vivo, the molecular and immunological mechanisms of action as a vaccine adjuvant are poorly understood. In this review, recent advances in particulate adjuvant research from the standpoint of innate immune responses are discussed.International Reviews Of Immunology 01/2013; 32(2):209-20. · 5.28 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Vaccines containing novel adjuvant formulations are increasingly reaching advanced development and licensing stages, providing new tools to fill previously unmet clinical needs. However, many adjuvants fail during product development owing to factors such as manufacturability, stability, lack of effectiveness, unacceptable levels of tolerability or safety concerns. This Review outlines the potential benefits of adjuvants in current and future vaccines and describes the importance of formulation and mechanisms of action of adjuvants. Moreover, we emphasize safety considerations and other crucial aspects in the clinical development of effective adjuvants that will help facilitate effective next-generation vaccines against devastating infectious diseases.Nature medicine 12/2013; 19(12):1597-608. · 28.05 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Vaccination is by far the most effective way of preventing morbidity and mortality due to infection of the upper respiratory tract by influenza virus. Current vaccines require yearly vaccine updates as the influenza virus can escape vaccine-induced humoral immunity due to the antigenic variability of its surface antigens. In case of a pandemic, new vaccines become available too late with current vaccine practices. New technologies that allow faster production of vaccine seed strains in combination with alternative production platforms and vaccine formulations may shorten the time gap between emergence of a new influenza virus and a vaccine becoming available. Adjuvants may allow antigen-sparing, allowing more people to be vaccinated with current vaccine production capacity. Adjuvants and universal vaccines can target immune responses to more conserved influenza epitopes, which eventually will result in broader protection for a longer time. In addition, further immunological studies are needed to gain insights in the immune features that contribute to protection from influenza-related disease and mortality, allowing redefinition of correlates of protection beyond virus neutralization in vitro.Viruses. 01/2014; 6(10):3809-3826.