{"author":[{"last_name":"Franschitz","first_name":"Anna","id":"480826C8-F248-11E8-B48F-1D18A9856A87","full_name":"Franschitz, Anna"}],"language":[{"iso":"eng"}],"day":"08","acknowledged_ssus":[{"_id":"LifeSc"}],"page":"89","year":"2023","abstract":[{"text":"Social insects fight disease using their individual immune systems and the cooperative\r\nsanitary behaviors of colony members. These social defenses are well explored against\r\nexternally-infecting pathogens, but little is known about defense strategies against\r\ninternally-infecting pathogens, such as viruses. Viruses are ubiquitous and in the last decades\r\nit has become evident that also many ant species harbor viruses. We present one of the first\r\nstudies addressing transmission dynamics and collective disease defenses against viruses in\r\nants on a mechanistic level. I successfully established an experimental ant host – viral\r\npathogen system as a model for the defense strategies used by social insects against internal\r\npathogen infections, as outlined in the third chapter. In particular, we studied how garden ants\r\n(Lasius neglectus) defend themselves and their colonies against the generalist insect virus\r\nCrPV (cricket paralysis virus). We chose microinjections of virus directly into the ants’\r\nhemolymph because it allowed us to use a defined exposure dose. Here we show that this is a\r\ngood model system, as the virus is replicating and thus infecting the host. The ants mount a\r\nclear individual immune response against the viral infection, which is characterized by a\r\nspecific siRNA pattern, namely siRNAs mapping against the viral genome with a peak of 21\r\nand 22 bp long fragments. The onset of this immune response is consistent with the timeline\r\nof viral replication that starts already within two days post injection. The disease manifests in\r\ndecreased survival over a course of two to three weeks.\r\nRegarding group living, we find that infected ants show a strong individual immune response,\r\nbut that their course of disease is little affected by nestmate presence, as described in chapter\r\nfour. Hence, we do not find social immunity in the context of viral infections in ants.\r\nNestmates, however, can contract the virus. Using Drosophila S2R+ cells in culture, we\r\nshowed that 94 % of the nestmates contract active virus within four days of social contact to\r\nan infected individual. Virus is transmitted in low doses, thus not causing disease\r\ntransmission within the colony. While virus can be transmitted during short direct contacts,\r\nwe also assume transmission from deceased ants and show that the nestmates’ immune\r\nsystem gets activated after contracting a low viral dose. We find considerable potential for\r\nindirect transmission via the nest space. Virus is shed to the nest, where it stays viable for one\r\nweek and is also picked up by other ants. Apart from that, we want to underline the potential\r\nof ant poison as antiviral agent. We determined that ant poison successfully inactivates CrPV\r\nin vitro. However, we found no evidence for effective poison use to sanitize the nest space.\r\nOn the other hand, local application of ant poison by oral poison uptake, which is part of the\r\nants prophylactic behavioral repertoire, probably contributes to keeping the gut of each\r\nindividual sanitized. We hypothesize that oral poison uptake might be the reason why we did\r\nnot find viable virus in the trophallactic fluid.\r\nThe fifth chapter encompasses preliminary data on potential social immunization. However,\r\nour experiments do not confirm an actual survival benefit for the nestmates upon pathogen\r\nchallenge under the given experimental settings. Nevertheless, we do not want to rule out the\r\npossibility for nestmate immunization, but rather emphasize that considering different\r\nexperimental timelines and viral doses would provide a multitude of options for follow-up\r\nexperiments.\r\nIn conclusion, we find that prophylactic individual behaviors, such as oral poison uptake,\r\nmight play a role in preventing viral disease transmission. Compared to colony defense\r\nagainst external pathogens, internal pathogen infections require a stronger component of\r\nindividual physiological immunity than behavioral social immunity, yet could still lead to\r\ncollective protection.","lang":"eng"}],"date_published":"2023-08-08T00:00:00Z","publication_identifier":{"isbn":["978-3-99078-034-3"],"issn":["2663 - 337X"]},"ddc":["570","577"],"citation":{"ista":"Franschitz A. 2023. Individual and social immunity against viral infections in ants. Institute of Science and Technology Austria.","mla":"Franschitz, Anna. <i>Individual and Social Immunity against Viral Infections in Ants</i>. Institute of Science and Technology Austria, 2023, doi:<a href=\"https://doi.org/10.15479/at:ista:13984\">10.15479/at:ista:13984</a>.","short":"A. Franschitz, Individual and Social Immunity against Viral Infections in Ants, Institute of Science and Technology Austria, 2023.","chicago":"Franschitz, Anna. “Individual and Social Immunity against Viral Infections in Ants.” Institute of Science and Technology Austria, 2023. <a href=\"https://doi.org/10.15479/at:ista:13984\">https://doi.org/10.15479/at:ista:13984</a>.","apa":"Franschitz, A. (2023). <i>Individual and social immunity against viral infections in ants</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:13984\">https://doi.org/10.15479/at:ista:13984</a>","ama":"Franschitz A. Individual and social immunity against viral infections in ants. 2023. doi:<a href=\"https://doi.org/10.15479/at:ista:13984\">10.15479/at:ista:13984</a>","ieee":"A. Franschitz, “Individual and social immunity against viral infections in ants,” Institute of Science and Technology Austria, 2023."},"title":"Individual and social immunity against viral infections in ants","article_processing_charge":"No","has_accepted_license":"1","alternative_title":["ISTA Thesis"],"publication_status":"published","month":"08","date_created":"2023-08-08T15:33:29Z","supervisor":[{"full_name":"Cremer, Sylvia","id":"2F64EC8C-F248-11E8-B48F-1D18A9856A87","first_name":"Sylvia","last_name":"Cremer","orcid":"0000-0002-2193-3868"}],"publisher":"Institute of Science and Technology Austria","degree_awarded":"PhD","status":"public","file":[{"file_size":10797612,"date_updated":"2024-03-01T08:51:42Z","creator":"afransch","access_level":"closed","date_created":"2023-08-08T18:01:28Z","embargo":"2024-08-08","embargo_to":"open_access","file_name":"Thesis_AnnaFranschitz_202308.pdf","checksum":"27220243d5d51c3b0d7d61c0879d7a0c","file_id":"13986","relation":"main_file","content_type":"application/pdf"},{"file_size":2619085,"date_updated":"2023-08-09T07:25:27Z","creator":"afransch","access_level":"closed","date_created":"2023-08-08T18:02:25Z","file_name":"Thesis_AnnaFranschitz_202308.docx","checksum":"40abf7ccca14a3893f72dc7fb88585d6","relation":"source_file","file_id":"13987","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document"},{"file_name":"Addendum_AnnaFranschitz202402.pdf","checksum":"8b991ecc2d59d045cc3cf0d676785ec7","embargo_to":"open_access","content_type":"application/pdf","relation":"erratum","file_id":"15042","description":"Minor modifications and clarifications - Feb 2024","date_updated":"2024-03-01T12:13:29Z","access_level":"closed","creator":"cchlebak","file_size":85956,"embargo":"2024-08-08","title":"Addendum","date_created":"2024-03-01T08:37:15Z"},{"checksum":"66745aa01f960f17472c024875c049ed","file_name":"Addendum_AnnaFranschitz202402.docx","file_id":"15043","relation":"source_file","content_type":"application/vnd.openxmlformats-officedocument.wordprocessingml.document","file_size":11818,"access_level":"closed","creator":"cchlebak","date_updated":"2024-03-01T08:51:42Z","date_created":"2024-03-01T08:39:20Z","title":"Addendum - source file"},{"checksum":"55c876b73d49db15228a7f571592ec77","file_name":"Print_Version_Franschitz_Anna_Thesis.pdf","content_type":"application/pdf","relation":"other","file_id":"15044","description":"For printing purposes","access_level":"closed","creator":"cchlebak","date_updated":"2024-03-01T12:58:14Z","file_size":10416761,"date_created":"2024-03-01T08:56:06Z","title":"Print Version"}],"_id":"13984","file_date_updated":"2024-03-01T12:58:14Z","type":"dissertation","date_updated":"2024-03-01T15:25:17Z","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","department":[{"_id":"GradSch"},{"_id":"SyCr"}],"oa_version":"Published Version","doi":"10.15479/at:ista:13984"}