Kunming Institute of Zoology

Researchers have shown that nasal drops with IgA antibodies can protect mice from SARS-CoV-2 infection. The results imply a new way to protect individuals at high risk from different variants of the SARS-CoV-2 virus and possibly other infections. Researchers at Karolinska Institutet in Sweden have shown that nasal drops with IgA antibodies can protect mice from SARS-CoV-2 infection. The results imply a new way to protect individuals at high risk from different variants of the SARS-CoV-2 virus and possibly other infections. The study is published in the Proceedings of the National Academy of Sciences. Different types of antibodies have different functions in the body. IgA antibodies are part of the so-called adaptive immune system and reside naturally in the mucosal membranes of the airways. Absence or low levels of mucosal IgA is known to be associated with an increased risk of SARS-CoV-2 breakthrough infections. The current COVID-19 vaccines mainly stimulate an IgG antibody response in the body, and earlier studies have shown that their ability to protect against infection with the new Omicron variants of the virus is limited. To overcome this, the group led by professor Qiang Pan-Hammarström at Karolinska Institutet used genetic engineering to create IgA antibodies that bind to the SARS-CoV-2 spike protein in a similar way to the IgG antibodies. Neutralized the virus effectively Mice infected with the Omicron variant received the IgA antibody treatment through nasal administration. The nasal drops significantly diminished the virus load in the trachea and lungs of the infected mice. The IgA antibodies were shown to bind stronger to the spike protein of SARS-CoV-2 and were more effective in neutralizing the virus compared to the original IgG antibodies. "The results show that these genetically engineered antibodies can strengthen the protection against new virus variants, but they are not intended to replace current vaccines," says Harold Marcotte, associate professor at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet, and the first author of the paper. "Traditional vaccines elicit an active immune response from the body, whereas this is a passive immunization strategy," he continues. "An active immunization approach that induces a mucosal immune response would be ideal, but hopefully our approach is suitable for protecting the most vulnerable individuals, like the elderly or immunocompromised persons." Promising strategy for other infections There are also hopes that the method can be used to neutralize other current and emerging variants of the virus. "We believe that this will be a very promising strategy, not only for COVID-19 and the new variants, but also for other infectious diseases, including influenza and other respiratory infections and gastric mucosal infections such as Helicobacter pylori, where there is no vaccine available at the moment," says Qiang Pan-Hammarström, professor at the same department and last author of the paper. The study was conducted within the European research consortium ATAC and through a collaborative effort between Sweden and China including Linköping University, Peking University, Guangzhou Institutes of Biomedicine and Health, Fudan University, Peking Union Medical College, Wuhan Institute of Virology, and Kunming Institute of Zoology. It was funded by EU's Horizon 2020 research and innovation program, a joint VR-NCSF funding, the Knut and Alice Wallenberg Foundation and the Swiss National Science Foundation grant BRIDGE. Some of the authors are listed as inventors of patents regarding antibody treatment.

For the first time, researchers successfully sequenced the genome of ancient human fossils from the Late Pleistocene in southern China. The data suggests that the mysterious hominin belonged to an extinct maternal branch of modern humans that might have contributed to the origin of Native Americans. For the first time, researchers successfully sequenced the genome of ancient human fossils from the Late Pleistocene in southern China. The data, published July 14 in the journal Current Biology, suggests that the mysterious hominin belonged to an extinct maternal branch of modern humans that might have contributed to the origin of Native Americans. "Ancient DNA technique is a really powerful tool," Su says. "It tells us quite definitively that the Red Deer Cave people were modern humans instead of an archaic species, such as Neanderthals or Denisovans, despite their unusual morphological features," he says. The researchers compared the genome of these fossils to that of people from around the world. They found that the bones belonged to an individual that was linked deeply to the East Asian ancestry of Native Americans. Combined with previous research data, this finding led the team to propose that some of the southern East Asia people had traveled north along the coastline of present-day eastern China through Japan and reached Siberia tens of thousands of years ago. They then crossed the Bering Strait between the continents of Asia and North America and became the first people to arrive in the New World. The journey to making this discovery started over three decades ago, when a group of archaeologists in China discovered a large set of bones in the Maludong, or Red Deer Cave, in southern China's Yunnan Province. Carbon dating showed that the fossils were from the Late Pleistocene about 14,000 years ago, a period of time when modern humans had migrated to many parts of the world. From the cave, researchers recovered a hominin skull cap with characteristics of both modern humans and archaic humans. For example, the shape of the skull resembled that of Neanderthals, and its brain appeared to be smaller than that of modern humans. As a result, some anthropologists had thought the skull probably belonged to an unknown archaic human species that lived until fairly recently or to a hybrid population of archaic and modern humans. In 2018, in collaboration with Xueping Ji, an archaeologist at Yunnan Institute of Cultural Relics and Archaeology, Bing Su at Kunming Institute of Zoology, Chinese Academy of Sciences, and his colleagues successfully extracted ancient DNA from the skull. Genomic sequencing shows that the hominin belonged to an extinct maternal lineage of a group of modern humans whose surviving decedents are now found in East Asia, the Indo-China peninsula, and Southeast Asia islands. The finding also shows that during the Late Pleistocene, hominins living in southern East Asia had rich genetic and morphologic diversity, the degree of which is greater than that in northern East Asia during the same period. It suggests that early humans who first arrived in eastern Asia had initially settled in the south before some of them moved to the north, Su says. "It's an important piece of evidence for understanding early human migration," he says. Next, the team plans to sequence more ancient human DNA by using fossils from southern East Asia, especially ones that predated the Red Deer Cave people. "Such data will not only help us paint a more complete picture of how our ancestors migrate but also contain important information about how humans change their physical appearance by adapting to local environments over time, such as the variations in skin color in response to changes in sunlight exposure," Su says.

In a collaborative study published online today in Nature Biotechnology, researchers from Kunming Institute of Zoology, Chinese Academy of Sciences, BGI, and other institutes, have completed the first genome sequence of domestic goat by a robust approach integrated with next-generation sequencing (NGS) and whole-genome mapping (WGM) technologies. The goat genome is the first reference genome for small ruminant animals and may help to advance the understanding of distinct ruminants' genomic features from non-ruminant species. This work also yields a valuable experience for facilitating the de novo assemblies of large, complex genomes in the future.