WASHINGTON: Researchers have discovered that Treg cells, a type of regulatory lymphocyte might be protecting babies in the womb from getting infected with the HIV virus if the mother is infected.
"Finding out what protects the majority of babies is important, as it can lead to ways to boost natural immune responses and make individuals resistant to HIV infection," said researcher Peter Kessler from the Emory University School of Medicine.
Scientists had been puzzled for years by the fact that only a minority of babies born to mothers with HIV infection get infected. Currently, HIV has no treatment but can be managed with life-long antiretroviral drugs.
Researchers found that levels of Treg lymphocytes were higher in the blood of newborn babies born to mothers with HIV infection but were healthy, compared with babies who were born with HIV infection.
Lymphocytes are cells of the immune system that protect the body by fighting bacteria and viruses. Treg cells, or regulatory T cells, are an important "self-check" in the immune system to prevent excessive immune reactions that could lead to tissue damage.
A research was conducted on 64 babies who were born HIV-uninfected and 28 babies born HIV-infected. The result which was presented at ASM Microbe, the American Society for Microbiology's annual meeting, showed that Treg cell levels were higher in HIV-infected infants. Hence, HIV virus can only infect cells that are activated, so Treg cells may be able to protect the body from an HIV infection by suppressing activation of other lymphocytes.
"Even though the number of babies studied is relatively small, these findings indicate that Treg, by controlling immune activation, may lower the vulnerability of the babies to HIV or other chronic infections even before they are born," said Kessler.
They analyzed the stored blood by flow cytometry, a technique that can differentiate between the different types of cells based on what markers they express on their surface. Regulatory T cells come in many forms with the most well-understood being those that express the markers CD4, CD25, and FOXP3.
These results could pave the way for the development of vaccines or other immune-based therapies that could be used together with medications to prevent the spread of HIV or other infections from mothers to their babies.