ANALYSIS OF THE EXPRESSION DYNAMICS OF HUMAN ENDOGENOUS RETROVIRUSES IN THE FEMALE CYCLE

• Grant number: 25/04824-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2025
• End date: May 31, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Luiz Henrique da Silva Nali
• Grantee: Maria Kauanne Oliveira Santos
• Host Institution: Universidade de Santo Amaro (UNISA). São Paulo , SP, Brazil

Abstract

Human endogenous retroviruses (HERVs), which represent approximately 8% of the human genome, result from the integration of viral elements into the germline of our ancestors. Their structure is similar to that of classical retroviruses, containing core genes (gag, pol/pro and env) and long terminal repeats (LTRs). Although frequently associated with autoimmune diseases, HERVs also exert physiological functions. The relationship between hormone levels in women and the action of genetic elements is still an open field of research. This domestication resulted in several physiological functions. In this case, Syncytin-1 is entirely encoded by the HERV-W envelope gene and this gene plays a role in the formation of the placenta. In addition, it is known that women have a higher HERV DNA load compared to men, and it is hypothesized that the X chromosome may contribute to this difference. To date, no clear and direct associations have been established between these two factors. Therefore, the present study aims to investigate the expression of HERVs in the female menstrual cycle and determine the levels of HERVs in each phase of menstruation. Thus, a case-control study will be conducted in which female volunteers aged 20 to 30 years will be selected. Three blood samples will be collected from each volunteer at three different times: on the 1st day of menstruation, on the 14th day (ovulation period) and on the 28th day (end of menstruation). The samples will consist of two tubes with ethylenediaminetetraacetic acid (EDTA) to obtain peripheral blood mononuclear cells (PBMC) and molecular analyses, in addition to a sample in a dry tube with separator gel to obtain serum, which will be used to quantify cytokines. Volunteers with a family history of autoimmune diseases or who use any contraceptive method will be excluded from the study. This approach will allow a deeper understanding of the relationship between HERVs and female physiology.