translated from Spanish: Researchers detected a parasite natural mechanism in the human placenta

an investigation d the Institute of Biomedical Sciences of the University of Chile (ICBM) detected a parasite natural mechanism in the human placenta, which could help to improve the understanding of the protective barriers of this and other organs to infections caused by certain pathogens.
The study, made in collaboration with Latin American and European scientists, explored the response of the placenta to infection by two parasites that cause diseases of high prevalence: the trypanozoma cruzi (Chagas disease) and toxoplasma gondii) toxoplasmosis).
“During pregnancy, the placenta has several functions that make it a super body”, explains the scientific leader of the study, the academic in the Faculty of Medicine of the U. of Chile, Ulrike Kemmerling. In relation to its function as a barrier to pathogens, their main conclusion was that the cell replacement of the trophoblast, which is part of the placental barrier, is part of the local innate immune response of the placenta.
“Knowing how the placenta is defends against multiple pathogens could give lights to in the future improve the mechanisms of defenses of this or other organs, identifying therapeutic targets, new molecules for diagnosis or markers that indicate the” probability that the fetus may acquire a disease,”added the researcher.
Ulrike Kemmerling Virulencia versus the probability of a pathogen infection immunity, whether virus, bacterium, fungus, or other, depends, on the one hand, of the infection (virulence factors) tools with which invade the host, and, on the other hand, the mechanisms with which it defends. One of them is the epithelial replacement, which represents one of the most basic mechanisms of immunity.
“The epithelia lining cover body surfaces and the cells that form these epithelia suffer a constant replacement, as it occurs in the skin. It is one of the most basic defense in humans mechanisms because any agent before invading has to adhere. Then if I have a pathogenic glued on a surface that is flaking, pathogens also go”.
The study noted how associated with Chagas disease parasite induces, in placental tissue, all cell processes associated with the epithelial replacement: proliferation, differentiation, and programmed cell death.
This also occurs in the placenta, where replaceable lining surface is called trophoblast. In the study, this placental epithelium demonstrated a particular behavior before the causative parasite of the chagas disease, a condition considered as unattended by who and who in recent years has been in the sights of the developed countries.
The infection is transmitted by different routes: a, vector, through vector insects commonly known as the vinchuca; and congenital, infected mother to son, through the placenta, among others. In the latter, the parasite must go through the placental barrier to reach the fetus in gestation.
“To be a neglected tropical disease means, in other words, affects poor people in poor countries. And that the pharmaceutical industry does not have much interest in developing new drugs. However, by migratory phenomena, their congenital variable is very important because it is responsible for that disease has appeared outside their endemic area, which is Latin America”, says Kemmerling.
Spain is one of the countries most affected in the European Union, which funded one of the collaborations of this research, specifically in Belgium (also formed art researchers from Uruguay, Argentina and Colombia). The scientist of the ICBM details that vertical transmission has a relatively low rate, between 1% and 10%, but will not know exactly the molecular mechanisms by which occurs.
“The exact fisiolopatologia passes from mother maternal blood to fetal via is not exactly known but is known that depends on factors relating to the parasite, the placenta and the immune system of the mother and the fetus that is developing. Of these components, the placenta is the least studied”.
The second line of research focused on Toxoplasma gondii, causative Protozoan of Toxoplasmosis. This disease is caused by infection the parasite that is found in the feces of cats and contaminated water. It can cause serious complications to pregnant women – if the first infection occurs during pregnancy – and people with weak immune systems.
“It is one of the most successful parasites worldwide: when infection occurs in pregnancy, the transmission rate is 70-80%” accurate.
Induction of immunity the initial purpose of the research was to explore how developed the processes of infection of the parasite in tissues. Science has focused, explains the researcher, accumulate knowledge about the infection of individual cells, but not in tissue. These are formed of different types of cells and extracellular matrices (such as collagen) and therefore constitute a much more complex environment for pathogens.
The placenta, in this sense, emerged as a suitable model of exploration of tissue, intermediate between pre clinical tests in humans and animal models in the laboratory. “We realize, first, that it is not easy to infect placenta”, has the DRA. Kemmerling. Concentrations near the hundred thousand parasites were required to obtain responses in the defensive systems of the body.
The analysis process began with the standardization of models from explant of the placenta, the calculation of the minimum concentration required to reproduce an infection and minimum tempos in the placenta was unable to tolerate the presence of pathogens. Thus, analyzing each component of the placenteria barrier with Histochemical and immunohistochemical methods they managed to establish impacts on different layers.
For the two pathogens, responses were dissimilar: while Trypanosoma cruzi induced activation of cell replacement of the trophoblast, hampering the infection in the placenta, Toxoplasma gondii destroying the protective layer, by activating enzymes that They degraded the protective collagen beneath the surface and, finally, crossing the placental barrier. In a real context, it unwelding easier, therefore, to the fetus.
The scientist explains that “when a study of the cardiac muscle of patients who die from a Chagasic cardiopathy, inside the heart cell parasites nests are observed, it is something characteristic, tissues infected by these nests of up to one hundred parasites. Not so in the placenta. Just removed chemically trophoblast, previous experimental infection of placenta explants, the nests can be detected. Hence the idea of its importance in the parasite defense”.
It destroys everything both parasites have multiple virulence factors that can cause alterations both molecular and cell and tissue levels. This infective capacity also depends on the strains: in the case of Toxoplasma gondii, these are grouped into three levels and each one of them described five or ten different strains.
Trypanoso is much more complex, because it is grouped into seven units, and each dpuede have thousands of different clones and strains. Different strains have also differences in terms of pathology that cause: digestive system and heart. The latter is the more common in Chile.
Trypanosoma cruzi induces in the placenta a cytokine profile – proteins the immune response regulatory-pro-inflamatorio. “Inflammation is the part of the immune response, in this case it is favorable, and makes good response to the pathogen.”
This does not happen in the case of Toxoplasma gondii: does not induce proinflammatory response and defenses decrease, still faced the same conditions of concentration of pathogens, so the absence of defensive response would also explain the infectious success of this pathogen.
“In the placenta, under the trophoblast is connective tissue that possesses an extracellular matrix composed mainly of collagen which is similar to the dermis, where are the fetal capillaries. Pathogens have to go through all that to reach the fetal maternal blood. And the ‘Toxo’ is able to destroy all”, emphasizes Dr. Kemmerling.
However, now lack explained how this process occurs and why the induction of a defensive activation occurs in one case and not in another: and is there where have embarked on a new study, with which this laboratory, housed in the anatomy and biology of the D program evelopment of ICBM, expected to contribute to seeking a response.
Its purpose: finding the mechanisms of cellular regulation that the parasite induces in the placenta to strengthen protection of the placental barrier. “We’re going to focus on micro RNA to see how it regulates the gene expression of these various factors involved in the epithelial replacement causing the parasite in the placenta (by: Luis Francisco Sandoval.)” Agency Ines Llambias communications).

Original source in Spanish