An effective protein based vaccine for tuberculosis (TB) will require a safe and effective adjuvant. There are few adjuvants in approved human vaccines, including Alum and the oil-in-water (o/w) based emulsions MF59 (Novartis Vaccines and Diagnostics), AS03 and AS04 (GlaxoSmith Kline Biologics, GSK) AF03 (Sanofi), and liposomes (Crucell). When used with pure, defined proteins, both Alum and emulsion adjuvants are effective at inducing primarily humoral responses. One of the newest adjuvants in approved products is AS04, which combines monophosphoryl lipid A (MPL), a TLR-4 agonist, with Alum. In this study, we compared two adjuvants, an o/w emulsion (SE), and an o/w emulsion incorporating glucopyranosyl lipid adjuvant (GLA), a synthetic TLR-4 agonist, together with a recombinant protein, ID93. Both the emulsion SE and GLA-SE adjuvants induce potent cellular responses in combination with ID93 in mice. ID93/SE induced Th2 biased immune responses, whereas ID93/GLA-SE induced multifunctional CD4+ Th1 cell responses (IFN-γ, TNF-α and IL-2). The ID93/GLA-SE vaccine candidate induced significant protection in mice and guinea pigs, whereas no protection was observed with ID93/SE, as assessed by reductions in bacterial burden, survival, and pathology. These results highlight the importance of properly formulating subunit vaccines with effective adjuvants for use against TB.
These results demonstrate the ability of therapeutic immunization to significantly enhance the efficacy of chemotherapy against tuberculosis and other infectious diseases, with implications for treatment duration, patient compliance, and more optimal resource allocation.
An easy-to-use tuberculosis skin test is developed with chitin microneedles that deliver purified protein derivative at the correct skin depth and result in a positive test in BCG-immunized guinea pigs.
Pulmonary tuberculosis (TB) remains one of the leading causes of infectious disease death despite widespread usage of the BCG vaccine. A number of new TB vaccines have moved into clinical evaluation to replace or boost the BCG vaccine including ID93+GLA-SE, an adjuvanted subunit vaccine. The vast majority of new TB vaccines in trials are delivered parenterally even though intranasal delivery can augment lung-resident immunity and protective efficacy in small animal models. Parenteral immunization with the adjuvanted subunit vaccine ID93+GLA-SE elicits robust TH1 immunity and protection against aerosolized Mycobacterium tuberculosis in mice and guinea pigs. Here we describe the immunogenicity and efficacy of this vaccine when delivered intranasally. Intranasal delivery switches the CD4 T cell response from a TH1 to a TH17 dominated tissue-resident response with increased frequencies of ID93-specific cells in both the lung tissue and at the lung surface. Surprisingly these changes do not affect the protective efficacy of ID93+GLA-SE. Unlike intramuscular immunization, ID93+GLA does not require the squalene-based oil-in-water emulsion SE to elicit protective CD4 T cells when delivered intranasally. Finally we demonstrate that TNF and the IL-17 receptor are dispensable for the efficacy of the intranasal vaccine suggesting an alternative mechanism of protection.
Globally, more people die annually from tuberculosis than from any other single infectious agent. Unfortunately, there is no commercially available vaccine that is sufficiently effective at preventing the acquisition of pulmonary tuberculosis in adults. In this study, preexposure prophylactic pulmonary delivery of active aerosolized antituberculosis bacteriophage D29 was evaluated as an option for protection against Mycobacterium tuberculosis infection. An average bacteriophage concentration of approximately 1 PFU/alveolus was achieved in the lungs of mice using a nose-only inhalation device optimized with a dose simulation technique and adapted for use with a vibrating mesh nebulizer. Within 30 min of bacteriophage delivery, the mice received either a low dose (∼50 to 100 CFU) or an ultralow dose (∼5 to 10 CFU) of M. tuberculosis H37Rv aerosol to the lungs. A prophylactic effect was observed, with bacteriophage aerosol pretreatment significantly decreasing M. tuberculosis burden in mouse lungs at 24 h and 3 weeks postchallenge (P < 0.05). These novel results indicate that a sufficient dose of nebulized mycobacteriophage aerosol to the lungs may be a valuable intervention to provide extra protection to health care professionals and other individuals at risk of exposure to M. tuberculosis.
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