Multiple myeloma (MM) is a plasma cell malignancy that is characterized by immune dysregulation. MM is commonly treated with immunomodulating agents, but still remains incurable. Herein, we proposed and evaluated immunostimulatory Lokon oncolytic adenoviruses (LOAd) for MM treatment. LOAd viruses are serotype 5/35 chimera, which enables infection of hematopoietic cells. Oncolysis is restricted to cells with a dysregulated retinoblastoma protein pathway, which is frequently observed in MM. Further, LOAd viruses are armed with human immunostimulatory transgenes: trimerized membrane-bound CD40L (LOAd700, LOAd703) and 4-1BBL (LOAd703). LOAd viruses were assessed in a panel of MM cell lines (ANBL-6, L363, LP-1, OPM-2, RPMI-8226, and U266-84). All cells were sensitive to infection, leading to viral replication and cell killing as analyzed by quantitative PCR and viability assay. Transgene expression was verified post infection with flow cytometry. Cell phenotypes were further altered with a downregulation of markers connected to MM progression (ICAM-1, CD70, CXCL10, CCL2, and sIL-2Rα) and an upregulation of the death receptor Fas. In a co-culture of immune and MM cells, LOAd viruses promoted activation of cytotoxic T cells as seen by higher CD69, CD107a, and IFNγ expression. This was most prominent with LOAd703. In conclusion, LOAd viruses are of interest for MM therapy.

中文翻译：

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针对 4-1BB 和/或 CD40 的多发性骨髓瘤的免疫刺激性溶瘤病毒疗法。

多发性骨髓瘤 (MM) 是一种浆细胞恶性肿瘤，其特征是免疫失调。MM 通常用免疫调节剂治疗，但仍然无法治愈。在此，我们提出并评估了用于 MM 治疗的免疫刺激性 Lokon 溶瘤腺病毒 (LOAd)。LOAd 病毒是血清型 5/35 嵌合体，能够感染造血细胞。溶瘤作用仅限于视网膜母细胞瘤蛋白通路失调的细胞，这在 MM 中很常见。此外，LOAd 病毒配备了人类免疫刺激转基因：三聚膜结合 CD40L（LOAd700、LOAd703）和 4-1BBL（LOAd703）。在一组 MM 细胞系（ANBL-6、L363、LP-1、OPM-2、RPMI-8226 和 U266-84）中评估了 LOAd 病毒。所有细胞都对感染敏感，通过定量 PCR 和活力测定进行分析，导致病毒复制和细胞杀伤。用流式细胞术在感染后验证转基因表达。通过下调与 MM 进展相关的标志物（ICAM-1、CD70、CXCL10、CCL2 和 sIL-2Rα）和上调死亡受体 Fas，进一步改变细胞表型。在免疫细胞和 MM 细胞的共培养物中，LOAd 病毒促进了细胞毒性 T 细胞的活化，如 CD69、CD107a 和 IFNγ 表达较高所见。这在 LOAd703 中最为突出。总之，LOAd 病毒对 MM 治疗感兴趣。和 sIL-2Rα) 和死亡受体 Fas 的上调。在免疫细胞和 MM 细胞的共培养物中，LOAd 病毒促进了细胞毒性 T 细胞的活化，如 CD69、CD107a 和 IFNγ 表达较高所见。这在 LOAd703 中最为突出。总之，LOAd 病毒对 MM 治疗感兴趣。和 sIL-2Rα) 和死亡受体 Fas 的上调。在免疫细胞和 MM 细胞的共培养物中，LOAd 病毒促进了细胞毒性 T 细胞的活化，如 CD69、CD107a 和 IFNγ 表达较高所见。这在 LOAd703 中最为突出。总之，LOAd 病毒对 MM 治疗感兴趣。