LONDON — In one of the most significant scientific discoveries of the last few years, researchers at Harvard have identified the first female link in a male-dominated family tree.
According to the findings of the new study, the genes of female ancestors are found in the same place in the male lineage that produces the protein that makes up the female’s immune system.
“This is the first time that the female-specific genes have been identified in the genes that form the immune system,” said lead researcher Jelena Tischenko, a professor in the Harvard School of Public Health.
“The finding is important because it means that we now know that, as a population, females and males are equally capable of protecting each other against disease.”
The research was published in the journal Nature on Sunday.
Tiscenko’s team studied gene expression in the female fetus and its mothers.
The team discovered that the genes in the fetus’s genes were found to be similar to those in the maternal genomes of both men and women.
The findings add to evidence that the immune systems of both sexes are capable of detecting the threat of disease and responding accordingly, Tiscoshenko said.
Taschenko and her colleagues identified more than 200 genes in both human and mouse fetal and maternal genomes that were differentially expressed between the sexes.
In addition to the genes identified as differentially-expressed in the fetal DNA, the researchers also found that the maternal genome showed significant differences.
The researchers identified genes that are also expressed in the immune cells of both women and men.
The finding could have implications for treating women with breast cancer, which are often thought to be due to the male-typical immune system of the woman.
However, Tascenko cautions that her research does not establish whether the immune responses of females and male fetuses are equally responsive.
“We did not find any differences in the response of the maternal immune system to the maternal antigen [in the fetus],” Tiscansky said.
“But there were no differences in immune responses in either fetal or maternal cells, suggesting that the paternal immune system is more important for the protection of the mother than the maternal immunoglobulin [the protein that protects the mother’s cells from pathogens].”
The researchers found that about 40 percent of the genes were expressed in women, and 20 percent were expressed at the level of the male fetus.
The research is important for understanding how the immune response to an antigen is expressed in fetal and human cells, Tideshenko said.
The authors also found some genes that were unique to the female immune system, which could be a useful tool for understanding the immune-system interactions in women with pre-existing conditions, such as cancer or allergies.
“These findings have profound implications for women with diseases that are usually thought to result from male-pattern immune responses, such an autoimmune disease, or immune deficiency,” said study co-author Sarah K. Smith, a research fellow at Harvard.
“For example, in women who have chronic asthma, the risk of developing asthma is high, so they could benefit from prenatal immunizations against the same immune response that we found in both fetal and female cells.”
The findings of Tiscchenko’s research have important implications for the prevention and treatment of diseases caused by inherited conditions such as breast cancer.
In a recent study published in Cell, researchers found evidence that an early form of the disease known as familial breast cancer (FBCC) in women has its origin in the effects of early exposure to maternal antibodies that target the T-cells of the fetus.
“A recent analysis of the genome of a patient with FBCC found that genes encoding the T antigen that protects cells from breast cancer were similar to genes encoding T-cell response genes in a woman with FDCC,” Tischenko said.
However “we have yet to identify which genes are involved in the T cell response in patients with FCDC, which means that this study may have important clinical implications.”
The new study does not directly answer the question of whether the fetus can become immunocompromised from a genetic disorder such as FBCE or if the immune mechanisms of the fetal brain and immune system are the same as those of the mothers.
However it does provide important insight into the possible effects of maternal immunizations on the development of immune systems and may help answer the questions of whether vaccines could be used to treat disease-causing mutations in the mother.
“There is still a lot we do not know about how the maternal and fetal immune systems are wired,” said Tisckovich.
While we know a lot about maternal immunity in humans, there are still many unknowns about fetal immunity and the potential role it may play in the development and severity of disease.”