FSASI "M.P. Chumakov Federal Scientific Center for Research and Development of Immunobiological Drugs of the Russian Academy of Sciences (Polio Institute)", 118819 Moscow, Russia.
Institute of Translational Medicine and Biotechnology, First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia.
Viruses. 2024 Feb 11;16(2):280. doi: 10.3390/v16020280.
The EMCV L and 2A proteins are virulence factors that counteract host cell defense mechanisms. Both L and 2A exhibit antiapoptotic properties, but the available data were obtained in different cell lines and under incomparable conditions. This study is aimed at checking the role of these proteins in the choice of cell death type in three different cell lines using three mutants of EMCV lacking functional L, 2A, and both proteins together. We have found that both L and 2A are non-essential for viral replication in HeLa, BHK, and RD cell lines, as evidenced by the viability of the virus in the absence of both functional proteins. L-deficient infection led to the apoptotic death of HeLa and RD cells, and the necrotic death of BHK cells. 2A-deficient infection induced apoptosis in BHK and RD cells. Infection of HeLa cells with the 2A-deficient mutant was finalized with exclusive caspase-dependent death with membrane permeabilization, morphologically similar to pyroptosis. We also demonstrated that inactivation of both proteins, along with caspase inhibition, delayed cell death progression. The results obtained demonstrate that proteins L and 2A play a critical role in choosing the path of cell death during infection, but the result of their influence depends on the properties of the host cells.
EMCV 的 L 和 2A 蛋白是对抗宿主细胞防御机制的毒力因子。L 和 2A 都具有抗凋亡特性，但现有数据是在不同的细胞系中并在不可比的条件下获得的。本研究旨在使用三种缺乏功能性 L、2A 和两种蛋白的 EMCV 突变体，在三种不同的细胞系中检查这些蛋白在选择细胞死亡类型中的作用。我们发现，L 和 2A 对于 HeLa、BHK 和 RD 细胞系中的病毒复制都不是必需的，这可以从缺乏两种功能性蛋白时病毒的生存能力证明。L 缺陷型感染导致 HeLa 和 RD 细胞发生凋亡，而 BHK 细胞发生坏死性死亡。2A 缺陷型感染诱导 BHK 和 RD 细胞发生凋亡。用 2A 缺陷型突变体感染 HeLa 细胞后，通过膜通透性导致 caspase 依赖性死亡，形态上类似于细胞焦亡。我们还证明，两种蛋白的失活以及 caspase 抑制作用会延迟细胞死亡进程。所得结果表明，蛋白 L 和 2A 在感染过程中选择细胞死亡途径方面发挥着关键作用，但它们影响的结果取决于宿主细胞的特性。
