Near-infrared laser to replace chemical vaccine adjuvant

描述（由申请人提供）：该提案探索了无组织损伤连续波（CW）近红外（NIR）激光增强适应性免疫应答的细胞和分子机制，并开发了一种安全有效的皮肤和粘膜疫苗接种免疫佐剂。这样做的最终目的是取代并发的化学或生物疫苗佐剂。虽然免疫佐剂通常是当前疫苗所必需的，但许多已获许可的和处于开发阶段的佐剂会引起显著的副作用。这需要开发新的安全有效的佐剂。用纳秒脉冲波（PW）可见范围激光照射皮肤先前已被证明可增强人类和小鼠对疫苗接种的免疫反应。然而，这些激光器需要共同施用额外的化学佐剂以诱导充分增加的免疫应答。此外，绿色或黄色光谱中的激光被黑色素吸收，导致不同皮肤光型的光吸收高度可变，因此限制了其临床应用。我们首次证明，在短时间内暴露于小面积皮肤的非组织损伤性NIR激光，不使用任何额外的试剂，增加了对流感抗原的广谱免疫反应。这发生在与许可的佐剂相当的程度上，并且导致在致死攻击鼠模型中存活率提高。使用低功率CW NIR激光器比PW可见光激光器以及许可的化学疫苗佐剂具有几个优点。由于水是NIR激光的主要发色团，因此不同皮肤光型的光吸收不会发生显著变化。激光降低了潜在的佐剂反应原性和毒性，因为它不会诱导长期的炎症细胞因子反应，不会促进过敏原性，并且与化学佐剂不同，不会在暴露的组织中持续存在。由于激光器在疫苗外部，它不会像常规疫苗-化学佐剂组合那样造成任何稳定性问题。这些具有启发性的发现提出了以下三个需要进一步调查的重要领域，我们将在本提案中予以解决：1）使用小鼠和雪貂中已建立的流感感染动物模型，探索皮肤中的NIR激光是否增强对基于皮肤的流感疫苗接种的长期回忆免疫应答，2）阐明近红外激光佐剂在体外和体内的细胞和分子作用机制，以及3）探索该技术在小鼠和雪貂粘膜疫苗接种中的应用。在该建议的高潮，我们的目标是证明在皮肤和粘膜疫苗接种的背景下，近红外激光佐剂的有效性和作用机制。该发现的可转化性通过成熟、安全、紧凑且相对简单的低瓦数CW NIR激光技术的当前可用性而增强，使得可以经济地生产便携式（手持）低成本装置，其在足够的疫苗接种量下可以替代化学佐剂。这种设备可能对当前的临床实践产生直接和巨大的影响。

DESCRIPTION (provided by applicant): This proposal explores the cellular and molecular mechanisms of a non-tissue damaging continuous wave (CW) near-infrared (NIR) laser to enhance adaptive immune responses, and develops a safe and effective immunologic adjuvant for skin and mucosal vaccination. The ultimate purpose of this is to replace a concurrent chemical or biological vaccine adjuvant. Although immunologic adjuvants are often essential for current vaccines, many licensed and development-stage adjuvants cause significant side effects. This necessitates the development of new safe and effective adjuvants. Illumination of the skin with nanosecond-pulsed wave (PW) visible range laser light has previously been shown to enhance immune responses to vaccination in humans and mice. However, these lasers require co-administration of an additional chemical adjuvant to induce a sufficiently increased immunological response. In addition, laser light in the green or yellow spectrums is absorbed by melanin, resulting in highly variable light absorption across different skin phototypes and therefore limiting its clinical utility. We have shown, for the first time, that that non-tissue damaging NIR laser light given in short exposures to small areas of the skin, without the use of any additional agents, increases a broad spectrum of immune responses to influenza antigen. This occurs at a magnitude comparable to licensed adjuvants, and results in improved survival in a lethal challenge murine model. Use of a low-power CW NIR laser has several advantages over PW visible light lasers, as well as licensed chemical vaccine adjuvants. Since water is the predominant chromophore for NIR laser light, light absorption is not significantly altered across different skin phototypes. The laser reduces potential adjuvant reactogenicity and toxicity, as it does not induce a prolonged inflammatory cytokine response, does not promote allergenicity, and unlike chemical adjuvants, does not persist in exposed tissues. Since the laser is external to a vaccine it does not pose any stability issues that conventional vaccine-chemical adjuvant combinations do. These provocative findings raise the following three important areas for further investigation that we will address in this proposal: 1) To explore whether NIR laser light in the skin enhances a long-term recall immune response to skin-based influenza vaccination using established animal models of influenza infection in mice and ferrets, 2) Elucidation of the cellula and molecular mechanisms of action of the NIR laser adjuvant in vitro and in vivo, and 3) Exploration of the use of this technology in mucosal vaccinations in mice and ferrets. Upon the culmination of this proposal, we aim to demonstrate the efficacy and mechanisms of action of the NIR laser adjuvant in the context of skin and mucosal vaccination. The translatability of this discovery is enhanced by the current availability of mature, safe, compact and relatively simple low-wattage CW NIR laser technology, making it possible to economically produce a portable (handheld) low cost device that, at sufficient vaccination volumes, could replace chemical adjuvants. Such a device could have an immediate and tremendous impact on current clinical practice.