Understanding defense mechanisms in the early days of embryonic development has taken an important step forward thanks to recent research focused on zebrafish embryosUntil now, it was unknown how humans dealt with bacterial infections before the emergence of the conventional immune system.
A set of studies carried out in Spain, led by teams from the Institute of Molecular Biology of Barcelona (IBMB-CSIC) and the Bellvitge Biomedical Research Institute (IDIBELL) has managed to record the process by which zebrafish embryos confront potentially dangerous bacteria. This discovery sheds light on early defensive strategies which, surprisingly, are also present in human embryos.
Epithelial phagocytosis: the first barrier against bacteria
During the initial stages of development, when neither the organs nor the immune system have formed, Zebrafish embryos use their surface epithelial cells to defend against infections. It has been observed that these cells are capable of capture and ingest bacteria through a cellular technique known as phagocytosis. This process is key to the early survival of embryos..
The study, published in the scientific journal 'Cell Host and Microbe', demonstrated that epithelial cells use protuberances of its membrane, in which the protein actin participates, to surround and trap bacteria such as 'Escherichia coli' and 'Staphylococcus aureus'One of the most striking data is the activation of immunity genes in these cells, which leads to the effective elimination of pathogens and promotes proper embryonic development.
Evolutionary origin of immunity and clinical applications
According to lead researcher Esteban Hoijman, this mechanism "could be the evolutionary origin of immunity» and represents the first recorded interaction between the developing embryo and its immediate biological environment. The existence of this innate defense before the conventional immune system opens new avenues for understanding How organisms protect their viability in the early days.
The discovery has potential practical implications. By better understanding how embryos cope with bacterial infections, we could improve fertility techniques, prevent malformations and optimize the development of new reproductive therapiesThe presence of this system in human embryos indicates a conserved function in animal evolution.
