title: A comparative study of stress-mediated immunological functions with the adjuvanticity of alum.
abstract: The efficacy of a vaccine is generally dependent on an adjuvant, which enhances the immune functions and alum has been widely used in human immunization. Alum activates the intracellular stress sensors inflammasomes, but whether these are responsible for the adjuvanticity is controversial. The objectives of this investigation were to examine the hypothesis that alum-mediated adjuvanticity is a function of stress and conversely that stress agents will elicit adjuvanticity. The investigation was carried out in BALB/c mice by SC immunization with ovalbumin (OVA) mixed with alum. This elicited inflammasomes, with significant activation of caspase 1, production of IL-1β, and adjuvanticity, demonstrated by enhancing OVA-specific serum IgG antibodies, CD4(+) T cells, and proliferation. The novel finding that alum induced HSP70 suggests that stress is involved in the mechanism of adjuvanticity. This was confirmed by inhibition studies with PES (phenylethynesulfonamide), which disrupts inducible HSP70 function, and inhibited both inflammasomes and the adjuvant function. Parallel studies were pursued with an oxidative agent (sodium arsenite), K-releasing agent (Gramicidin) and a metal ionophore (dithiocarbamate). All 3 stress agents induced HSP70, inflammasomes, and the adjuvant functions. Furthermore, up-regulation of membrane associated IL-15 on DC and CD40L on T cells in the animals treated with alum or the stress agents mediate the interactions between splenic CD11c DC and CD4(+) or CD8(+) T cells. The results suggest that the three stress agents elicit HSP70, a hallmark of stress, as well as inflammasomes and adjuvanticity, commensurate with those of alum, which may provide an alternative strategy in developing novel adjuvants.
authors.affiliation: Mucosal Immunology Unit, Kings College London, Tower Wing Floor 28, Guy's Hospital, London SE1 9RT, United Kingdom.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Mucosal Immunology Unit, Kings College London, Tower Wing Floor 28, Guy's Hospital, London SE1 9RT, United Kingdom.
authors.forename: Durdana
authors.initials: D
authors.lastname: Rahman
authors.affiliation: Mucosal Immunology Unit, Kings College London, Tower Wing Floor 28, Guy's Hospital, London SE1 9RT, United Kingdom. Electronic address: thomas.lehner@kcl.ac.uk.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lehner
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000534:Alum Compounds / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018053:Arsenites / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D020170:Caspase 1 / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D003713:Dendritic Cells / Q000276:immunology*; D004050:Ditiocarb / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006096:Gramicidin / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology; D006801:Humans; D007114:Immunization / Q000379:methods; D007074:Immunoglobulin G / Q000276:immunology; D058847:Inflammasomes / Q000276:immunology*; D019409:Interleukin-15 / Q000378:metabolism; D053583:Interleukin-1beta / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D017670:Sodium Compounds / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects* / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000900:Anti-Bacterial Agents; D018053:Arsenites; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D018840:HSP70 Heat-Shock Proteins; D007074:Immunoglobulin G; D058847:Inflammasomes; D019409:Interleukin-15; D053583:Interleukin-1beta; D016877:Oxidants; D017670:Sodium Compounds; D006096:Gramicidin; D023201:CD40 Ligand; C041524:aluminum sulfate; C017947:sodium arsenite; D010047:Ovalbumin; D004050:Ditiocarb; D020170:Caspase 1