One step closer to Zika Virus treatment: Zika Virus may finally have a vaccine soon, as scientists from the John Hopkins Bloomberg School of Public Health move a step closer to understanding the virus.
The team has identified the interaction between the virus and placenta in infected pregnant mice earlier during the pregnancy. The model is similar to observing the reproductive tract and travelling of virus across the placenta during the first trimester.
The significant study findings which are likely to help reach a cure for Zika were also published in the online journal Nature Communications, on 21st February.
In this first of its kind study, it was found that the virus disorganizes the placental layers, increases the risk of miscarriages and in cases of viable pregnancy, leads to serious inflammation of brain cells.
The uniquelydesigned mice in the study were divided in two groups; the experiment group was injected with Zika virus and the control group was infected with a mock infection. In the experiment group, the pregnancy viability for different Zika virus strains remained between 56% and 71%.
On the contrary, in the control group, the pregnancy viability was as high as 94%.
This mosquito-borne virus has been giving us nightmares since 2015 when its outbreak in Brazil made headlines globally first time in decades.
The infamous virus was first discovered in monkeys in Uganda in 1947, while the first human infected from the virus was reported from Nigeria in 1954.
Zika Virus Treatment: Global Health Horror
Researchers across the globe have unified their efforts to find a cure to this virus but none of the work has yielded fruitful reasons . The emphasis has thereby, remained on the prevention of virus spread by several methods.
Pregnant women are vulnerable to the virus, as infected mothers give birth to babies who suffer from microcephaly and severe neurological damage. In this context, the preventive protocol of disease spread primarily focused on restricting the travel of pregnant women to epidemic areas of the virus, not getting pregnant and the use of condoms in high risk areas.
In the efforts to combat the spread of virus, scientists have gone on to genetically engineer Zika virus causing mosquitoes to restrict their population by causing them to die before reaching maturity.
But with this study, scientists have now delved into the molecular complexities and immunological response of the body to Zika virus as it enters the body of an expecting mother in initial stages of pregnancy.
Looking At The Effect Of Zika On Immune Cells: Is A Cure Imminent?
As the immunology of mice has a different response compared to that of humans, the scientists of this study used a unique mice model which had an intact immune system. The presence of an intact immune system was further complemented by administering direct Zika virus titer injection into the reproductive tract; which ascertained that the elicited immune response was identical or closest possible to the immune response of humans.
Placenta is a crucial organ during pregnancy which provides the fetus with the oxygen and nutrient supplies for an optimal growth. It also acts as a physical barrier for the transfer of the bacteria, viruses and harmful material from the maternal bloodstream to the fetal bloodstream.
However, when Zika virus entered the reproductive tract of a pregnant mouse in the study, striking revelation about the placental barrier in association with the virus was made.
The presence of the virus in the system disrupted the normal organization of the placental cells which is the likely reason why the placenta fails to stop the virus from reaching the fetus in numerous Zika virus cases.
Interferons are the designated immune cells which neutralize the toxic effects of viral antigens invading the human system but they are rendered ineffective in cases of Zika virus.
The Zika invasion from different viral strains was found to intervene with the interferon signaling pathways, leading to maternal-fetal virus transmission.
As the virus entered into the system of developing fetus, it infected the progenitor neural cells leading to compromised brain cell development which resulted in disrupted cortex maturation. As the tissues of brain were inflamed, the babies of the experimented mice were born with thinner cortexes which others were miscarried before the pregnancy reached to term.
Zika Virus Treatment
The scientists are excited about the findings of their research and believe that observing the immune response to Zika in mice model is helpful in understanding the corresponding response in humans.
Sabra L. Klein, tudy co-author, an immunologist and microbiologist at the university said, “In the placentas of our mice, we’re seeing a defense against Zika being mounted but falling short, especially in early pregnancy, a time that corresponds to the first trimester in humans.”
Although, a lot is still unknown about link between the gestational age, infection risk and long term effects of maternal exposure to the virus.
Till now, it is believed that the exposure to the virus in the first trimester results in grave consequences in comparison to the exposure during second and third trimesters.
However, the molecular connection of the virus exposure, triggering of immune cells and infection penetration along the span of pregnancy is required to be studied in greater detail.
Nevertheless, with the surfacing of this study, the researchers hope to continue their work for finding an immunological drug target for stopping Zika transmission from the mother to the child.