Washington (ISJ) - People suffering from hormone deficiencies can look forward to a new therapy based on immune molecules from cows. The new therapy has been developed by scientists of the Florida-based The Scripps Research Institute (TSRI).
The research shows that human hormones and antibodies can be combined ? mimicking long, stalk-like cow antibodies. Antibodies combine chemically with substances which the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood.
The new study can also provide the foundation for treatments for a range of other diseases.
"We were inspired by this unique structure found in nature, and we assembled an antibody that might one day benefit humans," said TSRI Research Associate Tao Liu, co-first author of the new study with Yong Zhang at Calibr.
People suffering from Turner syndrome (which causes short stature in females), or low birth weight and other hormone deficiencies require injections of human growth hormone (hGH). But the body degrades hGH quickly, sometimes within 30 minutes.
"This means people need to inject themselves every day," explained Liu. "For a kid, that's really painful?and for a drug, that's really bad."
Antibodies, however, can last for weeks in the body.
The researchers were inspired by a bovine antibody study published by TSRI scientists in 2013. The bovine antibody has an unusual structure?a round base with a long amino-acid "stalk" pointing out. On the top of the stalk is a "knob region" that presumably binds to pathogens.
They wondered if they could switch the knob region with DNA from a human hormone, such as hGH. To test this theory, they used recombinant DNA technology to fuse hGH to a coiled version of the bovine antibody's stalks.
This fusion was stable. They next tried making an antibody-hormone molecule without any cow DNA, so that the molecules might someday be applied in human therapy.
The researchers then tested their antibody-hGH molecule in rat models. They found that hGH-deficient rats that received the treatment grew normally. In fact, the treated rats only needed injections two times a week to grow, compared with daily injections for rats given hGH without the antibody base.
"It acts just like the normal growth hormone," said Liu. "This means the treatment might only need to be injected once a week or even once a month in humans. It would be so much easier for patients."
Subsequent experiments showed no harmful side effects from the treatments.
The research team is working to optimize the treatment for potential use in humans, and Liu hopes the method could someday deliver longer-lasting doses of hGH?or maybe even insulin to treat type 2 diabetes?to patients in need.
Source: TSRI release
Image courtesy: TSRI/Schultz Lab