{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/349905"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/349905","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Investigating lymphocyte development in the foetal thymus and modulation by the melanocortin 5 receptor","abstract":"Lymphocyte development and activation are critical for the generation of effective protective immunity. Innate lymphoid cells and T cells play central roles in orchestrating bespoke immune reactions by producing specialised repertoires of immuno-regulatory cytokines. ILC2 and natural killer (NK) cells are generated in the bone marrow and thymus, whilst T cell development is restricted to the thymus. Once in the tissues, these cells respond to microenvironmental cues that refine their responses, for example, via receptor-mediated cell-cell contacts, soluble cytokines and neuropeptides. The co-development of ILC2, NK cells and T cells within a 5-day window in the foetal thymus provides a tractable system for studying their genesis and differentiation. Using combinatorial multicolour transcription factor reporter mouse lines, flow cytometry and confocal imaging I investigated the temporal stages of thymic innate lymphoid cell development. I found that NK cell progenitors (NKp) were first visible at embryonic (E) day E13.5, followed by the appearance of ILC2 progenitors (ILC2p) and developing T cells. Notably, the NKp and ILC2p formed clusters in the vicinity of medullary thymic epithelial cells (mTEC). To provide greater molecular insight into this cellular niche, single-molecule RNA fluorescence in situ hybridisation (smFISH) was performed on E17.5 foetal thymus to visually identify gene expression of 100 genes with single-cell resolution. This highlighted potential foetal thymus niche factors that may support innate lymphoid cell development. In the periphery ILC2, NK cells and T cells can respond to niche-derived factors to help initiate or potentiate immunity. Recent reports have highlighted the importance of tissue-resident stromal cells and neurons in this process, especially for ILC2. By analysing bulk RNAseq gene expression data, I identified Mc5r, encoding the fifth melanocortin receptor (Mc5r), as expressed more highly by ILC2 than ILC3. Treatment of mice with the neuropeptide alpha-melanocortin-stimulating hormone (αMSH), an agonist for melanocortin receptors, induced increases in the proportions of lung NK cells and T cells. The generation of a mouse line in which Mc5r was deleted in all lymphocytes (Il7r<sup>Cre</sup>Mc5r<sup>fl/fl</sup> mice) confirmed that Mc5r is required for normal NK cell and T cell representation in the lung at basal state, after IL-25 or IL-33 alarmin challenge and after viral respiratory infection of mice by the Pneumonia Virus of Mice.","abstract_html":"Lymphocyte development and activation are critical for the generation of effective protective immunity. Innate lymphoid cells and T cells play central roles in orchestrating bespoke immune reactions by producing specialised repertoires of immuno-regulatory cytokines. ILC2 and natural killer (NK) cells are generated in the bone marrow and thymus, whilst T cell development is restricted to the thymus. Once in the tissues, these cells respond to microenvironmental cues that refine their responses, for example, via receptor-mediated cell-cell contacts, soluble cytokines and neuropeptides. The co-development of ILC2, NK cells and T cells within a 5-day window in the foetal thymus provides a tractable system for studying their genesis and differentiation. Using combinatorial multicolour transcription factor reporter mouse lines, flow cytometry and confocal imaging I investigated the temporal stages of thymic innate lymphoid cell development. I found that NK cell progenitors (NKp) were first visible at embryonic (E) day E13.5, followed by the appearance of ILC2 progenitors (ILC2p) and developing T cells. Notably, the NKp and ILC2p formed clusters in the vicinity of medullary thymic epithelial cells (mTEC). To provide greater molecular insight into this cellular niche, single-molecule RNA fluorescence in situ hybridisation (smFISH) was performed on E17.5 foetal thymus to visually identify gene expression of 100 genes with single-cell resolution. This highlighted potential foetal thymus niche factors that may support innate lymphoid cell development. In the periphery ILC2, NK cells and T cells can respond to niche-derived factors to help initiate or potentiate immunity. Recent reports have highlighted the importance of tissue-resident stromal cells and neurons in this process, especially for ILC2. By analysing bulk RNAseq gene expression data, I identified Mc5r, encoding the fifth melanocortin receptor (Mc5r), as expressed more highly by ILC2 than ILC3. Treatment of mice with the neuropeptide alpha-melanocortin-stimulating hormone (αMSH), an agonist for melanocortin receptors, induced increases in the proportions of lung NK cells and T cells. The generation of a mouse line in which Mc5r was deleted in all lymphocytes (Il7r&lt;sup&gt;Cre&lt;/sup&gt;Mc5r&lt;sup&gt;fl/fl&lt;/sup&gt; mice) confirmed that Mc5r is required for normal NK cell and T cell representation in the lung at basal state, after IL-25 or IL-33 alarmin challenge and after viral respiratory infection of mice by the Pneumonia Virus of Mice.","abstract_has_math":false,"creators":["Heycock, Morgan"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["McKenzie, Andrew"],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-09-01","date_published":"2022-09-01","updated_at":"2026-07-22T22:24:21Z","subjects":["immunology","lung","mouse","thymus"],"languages":["eng"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/8d660b56-15f6-4eea-90e3-a7a4b87c8f41/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.96659","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["McKenzie, Andrew"]},{"key":"dc:creator","label":"Author","values":["Heycock, Morgan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2022-09-01"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/349905"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["immunology","lung","mouse","thymus"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/8d660b56-15f6-4eea-90e3-a7a4b87c8f41/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.17863/CAM.96659"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/fca705ed-af96-45b5-ac45-350e29f8606e/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Lymphocyte development and activation are critical for the generation of effective protective immunity. Innate lymphoid cells and T cells play central roles in orchestrating bespoke immune reactions by producing specialised repertoires of immuno-regulatory cytokines. ILC2 and natural killer (NK) cells are generated in the bone marrow and thymus, whilst T cell development is restricted to the thymus. Once in the tissues, these cells respond to microenvironmental cues that refine their responses, for example, via receptor-mediated cell-cell contacts, soluble cytokines and neuropeptides. The co-development of ILC2, NK cells and T cells within a 5-day window in the foetal thymus provides a tractable system for studying their genesis and differentiation. Using combinatorial multicolour transcription factor reporter mouse lines, flow cytometry and confocal imaging I investigated the temporal stages of thymic innate lymphoid cell development. I found that NK cell progenitors (NKp) were first visible at embryonic (E) day E13.5, followed by the appearance of ILC2 progenitors (ILC2p) and developing T cells. Notably, the NKp and ILC2p formed clusters in the vicinity of medullary thymic epithelial cells (mTEC). To provide greater molecular insight into this cellular niche, single-molecule RNA fluorescence in situ hybridisation (smFISH) was performed on E17.5 foetal thymus to visually identify gene expression of 100 genes with single-cell resolution. This highlighted potential foetal thymus niche factors that may support innate lymphoid cell development. In the periphery ILC2, NK cells and T cells can respond to niche-derived factors to help initiate or potentiate immunity. Recent reports have highlighted the importance of tissue-resident stromal cells and neurons in this process, especially for ILC2. By analysing bulk RNAseq gene expression data, I identified Mc5r, encoding the fifth melanocortin receptor (Mc5r), as expressed more highly by ILC2 than ILC3. Treatment of mice with the neuropeptide alpha-melanocortin-stimulating hormone (αMSH), an agonist for melanocortin receptors, induced increases in the proportions of lung NK cells and T cells. The generation of a mouse line in which Mc5r was deleted in all lymphocytes (Il7r<sup>Cre</sup>Mc5r<sup>fl/fl</sup> mice) confirmed that Mc5r is required for normal NK cell and T cell representation in the lung at basal state, after IL-25 or IL-33 alarmin challenge and after viral respiratory infection of mice by the Pneumonia Virus of Mice."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["8e49ca124e74b000fed40975a37633cd","87eda9de84448d1f82354d60eee3eb5f"]},{"key":"dc:title","label":"Title","values":["Investigating lymphocyte development in the foetal thymus and modulation by the melanocortin 5 receptor"]}]}],"canonical_facts":{"dc:contributor.advisor":["McKenzie, Andrew"],"dc:creator":["Heycock, Morgan"],"dc:date.issued":["2022-09-01"],"dc:description.abstract":["Lymphocyte development and activation are critical for the generation of effective protective immunity. Innate lymphoid cells and T cells play central roles in orchestrating bespoke immune reactions by producing specialised repertoires of immuno-regulatory cytokines. ILC2 and natural killer (NK) cells are generated in the bone marrow and thymus, whilst T cell development is restricted to the thymus. Once in the tissues, these cells respond to microenvironmental cues that refine their responses, for example, via receptor-mediated cell-cell contacts, soluble cytokines and neuropeptides. The co-development of ILC2, NK cells and T cells within a 5-day window in the foetal thymus provides a tractable system for studying their genesis and differentiation. Using combinatorial multicolour transcription factor reporter mouse lines, flow cytometry and confocal imaging I investigated the temporal stages of thymic innate lymphoid cell development. I found that NK cell progenitors (NKp) were first visible at embryonic (E) day E13.5, followed by the appearance of ILC2 progenitors (ILC2p) and developing T cells. Notably, the NKp and ILC2p formed clusters in the vicinity of medullary thymic epithelial cells (mTEC). To provide greater molecular insight into this cellular niche, single-molecule RNA fluorescence in situ hybridisation (smFISH) was performed on E17.5 foetal thymus to visually identify gene expression of 100 genes with single-cell resolution. This highlighted potential foetal thymus niche factors that may support innate lymphoid cell development. In the periphery ILC2, NK cells and T cells can respond to niche-derived factors to help initiate or potentiate immunity. Recent reports have highlighted the importance of tissue-resident stromal cells and neurons in this process, especially for ILC2. By analysing bulk RNAseq gene expression data, I identified Mc5r, encoding the fifth melanocortin receptor (Mc5r), as expressed more highly by ILC2 than ILC3. Treatment of mice with the neuropeptide alpha-melanocortin-stimulating hormone (αMSH), an agonist for melanocortin receptors, induced increases in the proportions of lung NK cells and T cells. The generation of a mouse line in which Mc5r was deleted in all lymphocytes (Il7r<sup>Cre</sup>Mc5r<sup>fl/fl</sup> mice) confirmed that Mc5r is required for normal NK cell and T cell representation in the lung at basal state, after IL-25 or IL-33 alarmin challenge and after viral respiratory infection of mice by the Pneumonia Virus of Mice."],"dc:format.checksum.md5":["8e49ca124e74b000fed40975a37633cd","87eda9de84448d1f82354d60eee3eb5f"],"dc:identifier.doi":["https://doi.org/10.17863/CAM.96659"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/fca705ed-af96-45b5-ac45-350e29f8606e/download"],"dc:language":["eng"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/349905"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/8d660b56-15f6-4eea-90e3-a7a4b87c8f41/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["immunology","lung","mouse","thymus"],"dc:title":["Investigating lymphocyte development in the foetal thymus and modulation by the melanocortin 5 receptor"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:21Z"}