Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland; Geneva Centre for Emerging Viral Diseases, University Hospitals Geneva, and University of Geneva, Switzerland.
Geneva Centre for Emerging Viral Diseases, University Hospitals Geneva, and University of Geneva, Switzerland; Division of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland.
Virus Res. 2024 Jan 2;339:199255. doi: 10.1016/j.virusres.2023.199255. Epub 2023 Nov 6.
SARS-CoV-2's genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicron's phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range, and may be relevant to the search for the putative intermediate host and reservoirs prior to the pandemic.
SARS-CoV-2 的遗传可塑性导致了几种令人关注的变体(VOCs)。在这里,我们研究了七种 SARS-CoV-2 分离株(B.1、Alpha、Beta、Gamma、Delta、Zeta 和 Omicron BA.1)在原代重建气道上皮(HAE)和肺源性细胞系中的复制能力。此外,为了研究与原始 SARS-CoV-2 相比,Delta 和 Omicron 的宿主范围,我们评估了这两种变体在来自 11 种非灵长类哺乳动物物种的 17 种细胞系中的复制情况,包括蝙蝠、啮齿动物、食虫动物和食肉动物。只有 Omicron 的表型在体外有所不同,其在鼻腔 HAE 中的复制速度很快但时间很短,并且能有效产生感染性病毒,这与其他 VOCs 不同,但在肺细胞系中并非如此。没有观察到其他物种的感染效率增加,但在 A549 细胞中,Delta 和 Omicron 的感染效率增加。值得注意的是,A549 和 Calu3 细胞中的复制能力低于鼻腔 HAE。我们的研究结果表明,VOCs 对人类的适应性更好,而宿主范围没有扩大,这可能与大流行前寻找潜在的中间宿主和储主有关。