A transcutaneous vaccination system using a hydrogel patch for viral and bacterial infection

Abstract

One of the most important anthropic missions is preventing the global spread of infectious diseases. Vaccination is the only available preventive treatment for infectious diseases, but the availability of vaccines in developing countries is not adequate. We report a simple, easy-to-use, noninvasive hydrogel patch transcutaneous vaccination system. Antigen (Ag)-specific IgG production was induced by applying an Ag-immersed patch to non-pretreated mouse auricle or hairless rat back skin. Immunofluorescence histochemical analysis revealed that Langerhans cells resident in the epidermal layer captured the antigenic proteins delivered by the hydrogel patch, which promoted the penetration of antigenic proteins through the stratum corneum, and that Ag-capturing Langerhans cells migrated into draining lymph nodes. Humoral immunity elicited by our transcutaneous vaccination system demonstrated neutralizing activity in both adenoviral infection and passive-challenge tetanus toxin experiments. The use of this hydrogel patch transcutaneous vaccination system will facilitate the global distribution of effective and convenient vaccines.

Fig. 1

OVA-specific Ab responses in C57BL/6 mice (A) and BALB/c mice (B) after transcutaneous vaccination with OVA. Mice were transcutaneously or intradermally vaccinated twice at 2-week intervals with OVA. Two weeks after the final vaccination, sera collected from these mice were assayed for OVA-specific IgG titer by ELISA. Titers of OVA-specific IgG1 and IgG2a subclasses were also assessed in BALB/c mice. Data are expressed as mean ± SD of results from five mice. N.D.; not detectable, TS: tape-stripped, t.c.; transcutaneous vaccination, i.d.; intradermal vaccination. Statistical significance was evaluated by one-way analysis of variance followed by Tukey's test for multiple comparisons. : ⁎; p < 0.01 versus non-immunized group. #; p < 0.05 versus transcutaneously vaccinated group.

Fig. 2

Sections of TR-OVA-immersed hydrogel patch formulation, and localization of TR-OVA in epidermal skin sheets and skin sections from mice vaccinated transcutaneously. The patch containing 100 µg TR-OVA was put on intact or tape-stripped auricle skin of mice. At various periods, the patch and auricles were harvested and frozen. Frozen sections (6-µm thick) were photographed using fluorescence microscopy. A; the patch just before application, B; the patch 24 h after skin application, C; intact skin 2 h after patch application, D; intact skin 12 h after patch application, E; tape-stripped skin 2 h after patch application, F; tape-stripped skin 6 h after patch application.

Fig. 3

Fluorescent microscopic images of epidermal sheets after application of a patch containing TR-OVA. The patch containing 100 µg TR-OVA was applied to intact or tape-stripped auricle skin of mice. Two hours later, auricles were harvested, and then epidermal sheets were prepared. The epidermal sheets were stained with AlexaFluor488-conjugated anti-mouse CD207 Ab for LCs, and then photographed using fluorescence microscopy.

Fig. 4

Fluorescence microscopy images of draining cervical LN sections after application with patch containing TR-OVA. The patch containing 100 µg TR-OVA was applied to intact or tape-stripped auricle skin of mice. Cervical LNs were harvested from these mice 2 d after 24-h patch treatment. Frozen sections (6-µm thick) were stained with AlexaFluor488-conjugated anti-mouse CD207 Ab, and then photographed using fluorescence microscopy.

Fig. 5

Inhibitory effects for Ad infection in mice vaccinated transcutaneously with Ad proteins. Mice were transcutaneously or intradermally vaccinated twice at 2-week intervals with Ad proteins. Two weeks after the final vaccination, sera collected from these mice were assayed to determine the Ad-specific IgG titer by ELISA (A). In addition, these mice were intravenously injected with Ad-Luc at vector particle titers of ≈ 10⁸. Two days later, luciferase activity in liver homogenates was determined by the luciferase assay system (B). Data are expressed as mean ± SD of results from five mice. N.D.; not detectable, TS: tape-stripped, t.c.; transcutaneous vaccination, i.d.; intradermal vaccination. Statistical significance was evaluated by one-way analysis of variance followed by Tukey's test for multiple comparisons. : ⁎; p < 0.05, ⁎⁎; p < 0.01, versus non-immunized group.