Laser facilitated epicutaneous peptide immunization using dry patch technology.

The skin has been intensely investigated as a target tissue for immunization because it is populated by multiple types of antigen presenting cells. Directly addressing dendritic cells or Langerhans cells in vivo represents an attractive strategy for inducing T cell responses in cancer immunotherapy. We and others have studied fractional laser ablation as a novel method combining efficient delivery of macromolecules to the skin with an inherent adjuvant effect of laser illumination. In this proof of concept study, we demonstrate the feasibility of peptide delivery to the skin using the P.L.E.A.S.E. professional Erb:YAG fractional infrared laser together with EPIMMUN patches. In an ovalbumin mouse model we demonstrate that a dry patch formulation of SIINFEKL peptide in combination with CpG-ODN1826, but not imiquimod or polyI:C, induces potent cytotoxic T cell responses, which can be further boosted by co-delivery of the pan-helper T cell epitope PADRE.

Phase I Study to Assess Safety of Laser-Assisted Topical Administration of an Anti-TNF Biologic in Patients With Chronic Plaque-Type Psoriasis.

Ablative fractional laser treatment facilitates epidermal drug delivery, which might be an interesting option to increase the topical efficacy of biological drugs in a variety of dermatological diseases. This work aims at investigating safety and tolerability of this new treatment approach in patients with plaque-type psoriasis. Eight patients with plaque-type psoriasis were enrolled in this study. All patients received (i) ablative fractional laser microporation (AFL) of a psoriatic lesion with an Er:YAG laser + etanercept (ETA; Enbrel® solution for injection) (AFL-ETA), (ii) ETA alone on another lesion, and, if feasible, (iii) AFL alone on an additional lesion. Overall, all treatment arms showed a favorable safety profile. AFL-ETA improved the lesion-specific TPSS score by 1.75 vs. baseline, whereas ETA or AFL alone showed a TPSS score improvement of 0.75 points, a difference that was not statistically significant and might be attributable to differences in baseline scores. Topical administration of ETA to psoriatic plaques via AFL-generated micropores was generally well-tolerated. No special precautions seem necessary in future studies. Clinical benefit will need assessment in sufficiently powered follow-up studies.

Laser-facilitated epicutaneous immunization of mice with SARS-CoV-2 spike protein induces antibodies inhibiting spike/ACE2 binding.

The skin represents an attractive target tissue for vaccination against respiratory viruses such as SARS-CoV-2. Laser-facilitated epicutaneous immunization (EPI) has been established as a novel technology to overcome the skin barrier, which combines efficient delivery via micropores with an inherent adjuvant effect due to the release of danger-associated molecular patterns. Here we delivered the S1 subunit of the Spike protein of SARS-CoV-2 to the skin of BALB/c mice via laser-generated micropores with or without CpG-ODN1826 or the B subunit of heat-labile enterotoxin of E.coli (LT-B). EPI induced serum IgG titers of 1:3200 that could be boosted 5 to 10-fold by co-administration of LT-B and CpG, respectively. Sera were able to inhibit binding of the spike protein to its receptor ACE2. Our data indicate that delivery of recombinant spike protein via the skin may represent an alternative route for vaccines against Covid-19.

Dual function of Langerhans cells in skin TSLP-promoted TFH differentiation in mouse atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is among the most common chronic inflammatory skin diseases, usually occurring early in life, and often preceding other atopic diseases such as asthma. TH2 has been believed to play a crucial role in cellular and humoral response in AD, but accumulating evidence has shown that follicular helper T cell (TFH), a critical player in humoral immunity, is associated with disease severity and plays an important role in AD pathogenesis. OBJECTIVES: This study aimed at investigating how TFHs are generated during the pathogenesis of AD, particularly what is the role of keratinocyte-derived cytokine TSLP and Langerhans cells (LCs). METHODS: Two experimental AD mouse models were employed: (1) triggered by the overproduction of TSLP through topical application of MC903, and (2) induced by epicutaneous allergen ovalbumin (OVA) sensitization. RESULTS: This study demonstrated that the development of TFHs and germinal center (GC) response were crucially dependent on TSLP in both the MC903 model and the OVA sensitization model. Moreover, we found that LCs promoted TFH differentiation and GC response in the MC903 model, and the depletion of Langerin+ dendritic cells (DCs) or selective depletion of LCs diminished the TFH/GC response. By contrast, in the model with OVA sensitization, LCs inhibited TFH/GC response and suppressed TH2 skin inflammation and the subsequent asthma. Transcriptomic analysis of Langerin+ and Langerin- migratory DCs revealed that Langerin+ DCs became activated in the MC903 model, whereas these cells remained inactivated in OVA sensitization model. CONCLUSIONS: Together, these studies revealed a dual functionality of LCs in TSLP-promoted TFH and TH2 differentiation in AD pathogenesis.

Laser-assisted intradermal delivery of adjuvant-free vaccines targeting XCR1+ dendritic cells induces potent antitumoral responses.

The development of vaccines inducing efficient CD8(+) T cell responses is the focus of intense research. Dendritic cells (DCs) expressing the XCR1 chemokine receptor, also known as CD103(+) or CD8α(+) DCs, excel in the presentation of extracellular Ags to CD8(+) T cells. Because of its high numbers of DCs, including XCR1(+) DCs, the skin dermis is an attractive site for vaccine administration. By creating laser-generated micropores through the epidermis, we targeted a model protein Ag fused to XCL1, the ligand of XCR1, to dermal XCR1(+) DCs and induced Ag-specific CD8(+) and CD4(+) T cell responses. Efficient immunization required the emigration of XCR1(+) dermal DCs to draining lymph nodes and occurred irrespective of TLR signaling. Moreover, a single intradermal immunization protected mice against melanoma tumor growth in prophylactic and therapeutic settings, in the absence of exogenous adjuvant. The mild inflammatory milieu created in the dermis by skin laser microporation itself most likely favored the development of potent T cell responses in the absence of exogenous adjuvants. The existence of functionally equivalent XCR1(+) dermal DCs in humans should permit the translation of laser-assisted intradermal delivery of a tumor-specific vaccine targeting XCR1(+) DCs to human cancer immunotherapy. Moreover, considering that the use of adjuvants in vaccines is often associated with safety issues, the possibility of inducing protective responses against melanoma tumor growth independently of the administration of exogenous adjuvants should facilitate the development of safer vaccines.

Efficacy, tolerability and safety of propiverine hydrochloride in comparison to oxybutynin in children with urge incontinence due to overactive bladder: Results of a multicentre observational cohort study.

OBJECTIVE: To compare, in a retrospective observational cohort study, the efficacy, tolerability and safety of propiverine and oxybutynin in children with urge incontinence (UI) due to overactive bladder. PATIENTS AND METHODS: Medical records were scrutinized for children with UI. As a primary efficacy outcome variable the achievement of continence after treatment with variable doses of propiverine or oxybutynin was assessed. Weekly UI episodes and daily voiding frequency were evaluated as secondary efficacy outcomes. Tolerability was evaluated by the rate of adverse events, adverse drug reactions caused by antimuscarinics and premature treatment termination. RESULTS: At 16 study centres, 621 children aged 5-14 years with UI due to overactive bladder were enrolled. After anticholinergic treatment (437 propiverine, 184 oxybutynin) continence was achieved in 61.6% and 58.7% of the patients after 186 and 259 days, respectively. There were clinically relevant improvements in voiding frequency across treatment groups. Daily doses of propiverine were markedly below the recommendations (0.54 vs 0.8 mg/kg body weight), daily doses of oxybutynin were according to the recommendations (0.31 vs 0.2-0.4 mg/kg body weight) at treatment initiation. There was a significantly more favourable tolerability to propiverine than oxybutynin for the overall rate of adverse events (3.9% vs 16.3%, odds ratio 4.813), adverse drug reactions caused by propiverine or oxybutynin (2.8% vs 9.2%) and premature treatment termination due to adverse drug reactions (1.6% vs 4.4%). CONCLUSION: Propiverine and oxybutynin are effective in children with UI due to overactive bladder. Sufficient treatment periods of at least 2, preferably 3-4, months are the crucial factors for a successful treatment. The tolerability profile of propiverine is better than for oxybutynin.