Sperm provides clue to 'disease immunity'

London, Dec 20 (UNI) Sperms could provide a vital clue as to why vaccines against deseases like HIV and cancer do not work and allow them to spread in the body, experts have revealed.

Researchers have identified sugar-based markers on human sperm cells, which prevent them from being attacked by the female immune system are also found on cancer cells and HIV-infected blood cells and may help the diseases to take hold.

The markers are believed to tell the female immune system that the sperm are not dangerous pathogens, and therefore should not be attacked by the woman's white blood cells during the reproductive process.

Researcher Anne Dell from Imperial College London's Department of Life Sciences said the same kind of marker was also found on some types of cancer cells, some bacterial cells, some parasitic worms and HIV infected white blood cells.

These markers are believed to allow such dangerous cells and pathogens to evade destruction by the human immune system, leading to serious and sometimes fatal illness.

Aggressive cancers and pathogens might be using the same system of universally-recognisable markers to trick the immune system into thinking they're harmless, Science Daily quoted Ms Dell as saying.

Further research would help in understanding the working of these markers at a basic biological and chemical level could lead to new ways to treat or prevent cancers and other diseases in the future.

''It's our major Achilles heel,'' co-author Gary Clark, University of Missouri School of Medicine, was quoted as saying.

''Reproduction is required for the survival of our species.

Therefore, we are 'hard-wired' to protect our sperm and eggs as well as our unborn babies from any type of immune response.

Unfortunately, our results suggest that many pathogens and tumor cells have also integrated themselves into this protective system, thus enabling them to resist the human immune response.'' UNI