AUSTRALIAN researchers have developed cows’ milk that protects human cells from Human Immuno-deficiency Virus (HIV) that causes Acquired Immuno Deficiency Syndrome (AIDS).
The milk contains antibodies, which defend against HIV. The next step will be to develop it into a cream, which women can apply to protect themselves from contracting HIV from sexual partners.
Melbourne University’s Dr. Marit Kramski and colleagues found that using cows to produce HIV-inhibiting antibodies is cheaper than existing methods. They worked with Australian biotechnology company Immuron Ltd to develop the milk.
The scientists vaccinated pregnant cows with an HIV protein and studied the first milk that cows produced after giving birth. The first milk, called the colostrum, is naturally packed with antibodies to protect the newborn calf from infections. The vaccinated cows produced HIV antibodies in their milk.
“We were able to harvest antibodies specific to the HIV surface protein from the milk,” said Marit, who is presenting her research this week as one of the winners of Fresh Science—a national program for early-career scientists. “We have tested these antibodies and found in our laboratory experiments that they bind to HIV and that this inhibits the virus from infecting and entering human cells,” she said.
Cows cannot contract HIV. But their immune systems develop antibodies against the foreign protein. The HIV-inhibiting antibodies from cows’ milk will be developed into a cream called a microbicide that is applied into the vagina before and /or after sex to protect women from contracting sexually transmitted infections.
Other microbicides are being developed around the world but the antibodies in this research are easier and cheaper to produce, providing a new HIV-prevention strategy. “We hope that our anti-HIV milk antibodies will provide a user-friendly, female-controlled, safe and effective tool for the prevention of sexually acquired HIV infection,” Marit said. “If proven effective in humans, it will empower women to protect themselves against HIV.”
About 30 million people are living with HIV globally and there is presently no effective vaccine for humans.
The research was supported by the Australian Centre for HIV and Hepatitis Virology Research and the NHMRC. Marit and her colleagues are now developing plans for animal and human studies. Marit Kramski is one of 12 early career scientists unveiling their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Australian Government.
Meanwhile, as a vaginal gel, the antiretroviral tenofovir can protect women against being infected with HIV during sex, but it needs to be used every time. To get around any problems with compliance, a team from the University of Utah and the reproductive health research organization CONRAD, United States, are developing a vaginal ring that can be left in place and deliver tenofovir gradually over 90 days, which could give women long-term protection against HIV infection.
Treatments for HIV have improved vastly since the approval of the first antiretroviral in 1987, with many people treated with combinations of drugs living with almost undetectable levels of virus in their blood. However, the ideal is stopping infection in the first place. Condoms are the simplest method, and antiviral gels, such as tenofovir gel, have also been effective. But these are not always available, and in some environments and situations may not be convenient or acceptable.
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