Periodic Reporting for period 1 - HOST-SELECT (Functional Analysis of Host Genetic Variants: Biomarker Selection Towards Improving Female Subfertility Diagnosis and Treatment)
Berichtszeitraum: 2017-07-01 bis 2019-06-30
The main purpose of this proposal was to test the role of individual genetic make-up in human tubal pathologies caused by a genital infection with Chlamydia trachomatis (CT). CT is the most common bacterial sexually transmitted infection, with more than 100 million new infections each year. Studies show that tubal infection with CT may lead to serious pathological complications, such as infertility and ectopic pregnancy.
Fertility issues affect roughly 15% of couples attempting to conceive, hence they represent a significant public health concern. The prevalence of fertility issues is expected to increase, partly due to the rising rates of CT infections. Researchers have shown that, following a genital CT infection, women carrying particular gene variants (single nucleotide polymorphisms; SNPs) have a higher risk of developing these complications, compared to those women that have not inherited these variants. How these differences in risk are driven by SNPs is not sufficiently understood.
Identifying key genetic factors in tubal pathologies and understanding how they contribute to these conditions would potentially advance screening and therapy of individuals suffering from these issues. We have therefore a) set out to determine which key genes and their variants play a role in CT-caused tubal pathology and b) tested the effect of these variants in a 3D organoid model of a human Fallopian tube – currently the most advanced research model for tubal infection. As a personal goal, an additional purpose of the proposal was to obtain specific skills and expertise in techniques, among others cultivation of tubal 3D organoids from cells obtained from patients, their application in SNP studies of CT infection and genetic manipulation in these organoids.
Fertility issues affect roughly 15% of couples attempting to conceive, hence they represent a significant public health concern. The prevalence of fertility issues is expected to increase, partly due to the rising rates of CT infections. Researchers have shown that, following a genital CT infection, women carrying particular gene variants (single nucleotide polymorphisms; SNPs) have a higher risk of developing these complications, compared to those women that have not inherited these variants. How these differences in risk are driven by SNPs is not sufficiently understood.
Identifying key genetic factors in tubal pathologies and understanding how they contribute to these conditions would potentially advance screening and therapy of individuals suffering from these issues. We have therefore a) set out to determine which key genes and their variants play a role in CT-caused tubal pathology and b) tested the effect of these variants in a 3D organoid model of a human Fallopian tube – currently the most advanced research model for tubal infection. As a personal goal, an additional purpose of the proposal was to obtain specific skills and expertise in techniques, among others cultivation of tubal 3D organoids from cells obtained from patients, their application in SNP studies of CT infection and genetic manipulation in these organoids.
Firstly, we needed to adapt the tubal organoid model to our specific needs, to allow for both infection with CT and unhindered interaction with other types of cells introduced into the model. This modification enabled us to examine the effect CT infection has on the tubal surface. As a result, we were able to detect changes to the ‘normal’ microenvironment in the tube induced by CT, resulting in different levels of inflammation and disruptions to its physiological function.
Secondly, we conducted a comparison of our earlier research findings on CT-caused tubal pathology with the host group’s data in order to seek most promising and most reliable gene and SNP candidates. The key strength of our previous findings is the fact that they were obtained by studying 2500 samples from female patients diagnosed with CT infection and/or tubal pathology. Thanks to the opportunity to collaborate with the host group, we were able to compare our data with their analyses of the activity of genes in the infected tubal organoid model. As a result, we produced a list of 15 gene variants (within 12 genes) that we wanted to continue focusing on in our project.
Our main emphasis was on a gene for a particular chemical signal molecule secreted in the tube, particularly in the presence of an ongoing tubal CT infection. We tested the effect of SNPs from several different genes known to interact with this factor. Based on our findings, we were able to conclude that the production of the factor in our CT-infected organoid model depends on the presence or absence of individual studied SNPs. We detected that its production is higher if a particular SNP variant is present in at least one gene copy. Furthermore, we observed that active acute CT infection alters the presence of several proteins on the inner surface of the Fallopian tube. These observations suggest that CT infection may likely change the inflammatory conditions in the Fallopian tube and promote tubal pathology, depending on a woman’s genetic profile.
Finally, knowledge and skills gathered in this project are to be used in developing new modified study models for tubal complications. Experience from building our model can be applied in the process of developing models of other organs, or models for studying other infections.
Secondly, we conducted a comparison of our earlier research findings on CT-caused tubal pathology with the host group’s data in order to seek most promising and most reliable gene and SNP candidates. The key strength of our previous findings is the fact that they were obtained by studying 2500 samples from female patients diagnosed with CT infection and/or tubal pathology. Thanks to the opportunity to collaborate with the host group, we were able to compare our data with their analyses of the activity of genes in the infected tubal organoid model. As a result, we produced a list of 15 gene variants (within 12 genes) that we wanted to continue focusing on in our project.
Our main emphasis was on a gene for a particular chemical signal molecule secreted in the tube, particularly in the presence of an ongoing tubal CT infection. We tested the effect of SNPs from several different genes known to interact with this factor. Based on our findings, we were able to conclude that the production of the factor in our CT-infected organoid model depends on the presence or absence of individual studied SNPs. We detected that its production is higher if a particular SNP variant is present in at least one gene copy. Furthermore, we observed that active acute CT infection alters the presence of several proteins on the inner surface of the Fallopian tube. These observations suggest that CT infection may likely change the inflammatory conditions in the Fallopian tube and promote tubal pathology, depending on a woman’s genetic profile.
Finally, knowledge and skills gathered in this project are to be used in developing new modified study models for tubal complications. Experience from building our model can be applied in the process of developing models of other organs, or models for studying other infections.
Our results are the first example of specific SNPs being tested in a tubal organoid model infected with Chlamydia trachomatis. This project builds upon previous research efforts with the purpose of identifying genes and SNPs that can serve as potential screening markers as well as targets for novel therapies for conditions such as infertility. Envisioned as an ambitious social impact, our findings will help us select a panel of relevant genes and genetic variants, aiding the development of a diagnostic genetic assay for women with fertility issues. Current medical diagnostic protocols cannot identify all women with tubal pathology. Simultaneously, many women temporarily unable to conceive will unnecessarily be subjected to invasive and costly surgical examinations. The ability to better estimate a woman’s risk of tubal pathology as a result of a Chlamydia infection would bring new opportunities for patient care. Evidently, improving these diagnostic protocols could have a profound public health impact, in terms of quality of life, costs and innovation.
Additionally, knowledge and skills gathered in this project provide an insight into new applications of 3D organoids as models for studying tubal infections and ensuing complications. Organoids – developed from isolated patient cells into tissue-like structures so as to optimally simulate living conditions – are being increasingly used in the biomedical field and are advancing research opportunities beyond animal models and Petri dish cell lines. Experience from building and utilising our model can be applied by researchers and clinicians in the process of developing organoid models of other organs, or models for studying other infections.
Additionally, knowledge and skills gathered in this project provide an insight into new applications of 3D organoids as models for studying tubal infections and ensuing complications. Organoids – developed from isolated patient cells into tissue-like structures so as to optimally simulate living conditions – are being increasingly used in the biomedical field and are advancing research opportunities beyond animal models and Petri dish cell lines. Experience from building and utilising our model can be applied by researchers and clinicians in the process of developing organoid models of other organs, or models for studying other infections.