Developing immunosuppressive therapies for autoimmune diseases comes with a caveat that immunosuppression may promote the risk of developing other conditions or diseases. We have previously shown that biolistic delivery of an expression construct encoding inducible HSP70 (HSP70i) with one amino acid modification in the dendritic cell (DC) activating moiety 435–445 (HSP70i_Q435A) to mouse skin resulted in significant immunosuppressive activity of autoimmune vitiligo, associated with fewer tissue infiltrating T cells. To prepare HSP70i_Q435A as a potential therapeutic for autoimmune vitiligo, in this study we evaluated whether and how biolistic delivery of HSP70i_Q435A in mice affects anti-tumor responses. We found that HSP70i_Q435A in fact supports anti-tumor responses in melanoma-challenged C57BL/6 mice. Biolistic delivery of the HSP70i_Q435A-encoding construct to mice elicited significant anti-HSP70 titers, and anti-HSP70 IgG and IgM antibodies recognize surface-expressed and cytoplasmic HSP70i in human and mouse melanoma cells. A peptide scan revealed that the anti-HSP70 antibodies recognize a specific C-terminal motif within the HSP70i protein. The antibodies elicited surface CD107A expression among mouse NK cells, representative of antibody-mediated cellular cytotoxicity (ADCC), supporting the concept, that HSP70i_Q435A-encoding DNA elicits a humoral response to the stress protein expressed selectively on the surface of melanoma cells. Thus, besides limiting autoimmunity and inflammation, HSP70i_Q435A elicits humoral responses that limit tumor growth and may be used in conjunction with immune checkpoint inhibitors to not only control tumor but to also limit adverse events following tumor immunotherapy.

开发针对自身免疫性疾病的免疫抑制疗法伴随着一个警告，即免疫抑制可能会增加患其他病症或疾病的风险。我们之前已经表明，将编码诱导型 HSP70 (HSP70i) 的表达构建体在树突状细胞 (DC) 激活部分 435-445 (HSP70i _Q435A ) 中进行一个氨基酸修饰的基因枪递送至小鼠皮肤导致显着的自身免疫性白癜风的免疫抑制活性，与较少的组织浸润 T 细胞相关。为了制备 HSP70i _Q435A作为自身免疫性白癜风的潜在治疗剂，在本研究中，我们评估了 HSP70i _Q435A在小鼠体内的基因枪递送是否以及如何影响抗肿瘤反应。我们发现 HSP70i _Q435A事实上支持黑色素瘤攻击的 C57BL/6 小鼠的抗肿瘤反应。HSP70i _Q435A编码构建体向小鼠的基因射_弹递送引发了显着的抗 HSP70 滴度，并且抗 HSP70 IgG 和 IgM 抗体识别人和小鼠黑色素瘤细胞中表面表达的和细胞质的 HSP70i。肽扫描显示抗 HSP70 抗体识别 HSP70i 蛋白内的特定 C 端基序。抗体在小鼠 NK 细胞中引发表面 CD107A 表达，代表抗体介导的细胞毒性 (ADCC)，支持这样一个概念，即编码HSP70i _{Q435A 的}DNA 引发对黑色素瘤细胞表面选择性表达的应激蛋白的体液反应。因此，除了限制自身免疫和炎症，HSP70i_Q435A引发限制肿瘤生长的体液反应，可与免疫检查点抑制剂联合使用，不仅控制肿瘤，还限制肿瘤免疫治疗后的不良事件。