In WP1, I successfully identified HPV8-E6 as the individual HPV8 early region gene responsible for expansion of the novel Lrig1 defined hair follicle junctional zone keratinocyte stem cell (HF-JZ-KSC) population. Moreover, I have found the E6 gene is associated with KSC proliferation through expression of ΔNp63.
In WP2 I have sought to determine which signalling pathway(s) is/are perturbed in HPV8tg-CER mice, resulting in ΔNp63 overexpression. Taking the advantage of a high-throughput screening technique, RNA-Seq, I identified STAT3 as the pathway upregulated in the Lrig1 population of HPV8 mice compared to the control population CD34. In addition, as crucial validation for our findings, I have studied HPV8tg-CER:STAT3+/- mice, that are hemizygous for the STAT3 gene and are less prone to tumorigenesis, enabling assessment of the Lrig1 HF-JZ-KSC. As expected, there was no expansion of the level of Lrig1 population in the CER-HPV8:STAT3+/- mice, and the population was comparable to WT.
In WP3 I planned to translate the finding of WP2 to the human context and determine the signalling pathway(s) responsible for ΔNp63 overexpression in human skin FC. I have selected the samples that show cytopathic effect and detect the presence β-HPV genotypes using an RHA analysis that allow inspect the DNA level and immunofluorescence analysis that observe the protein level. Yet there was not the possibility to accomplish some part of the WP3 such as analyse the pathway involved in the human AK.
Lastly, I completed WP4 in which I determined whether immunosuppression promotes SCC formation in HPV8 transgenic mice. I completed the breeding of HPV8tg-CER with Rag2-KO mice (which lack B and T cells), in order to recreate a mouse model that recapitulate the effect of immunosuppression on HPV8 infection. In the HPV8tg-CER:Rag2KO the size of Lrig1 population increased when compared to the normal counterpart such as Rag2KO only. Furthermore, I compared the rate and frequency of tumour formation in HPV8tg mice versus HPV8tg-CER:Rag2KO deficient mice. Strikingly, a large fraction of HPV8tg-CER:Rag2KO mice developed papilloma at earlier time points when compared to HPV8tgCER mice.
In closing, the work that has been completed during the action, using mouse models of HPV8 (HPV8tg-CER, HPV8tg-E2, HPV8tg-E6, HPV8tg-E7), enable the identification of E6 of β-HPV as the early region gene involved in the expansion of the Lrig1 HF-JZ-KSC population through increased ΔNp63 expression.
The work undertaken has contributed to the state of the art of the keratinocytes stem cell field.
The plan for dissemination and exploitation of results has been fully realized and exceeded.
During the action I have developed a strong network with scientist in the field. This has been possible through the attendance and active participation with work presentation to several conferences.
These conferences have allowed me to meet with the collaborators that kindly offered the mice (Professor Akgul, Professor Gariglio) and the cell line (professor Smola) stated in the action.
I have taken part in many public engagement activities throughout the project, including “FUTURES”, the European Researchers’ Night at the @we the curious event held in Bristol. I also took part in the application for get funds for the first European Researchers’ Night to be held in Cardiff that has recently been awarded.
