Researchers have long found that HIV genes can be detected in saliva of AIDS patients, but these viruses cannot infect other cells. In1980s and1990s, epidemiological analysis has found that the possibility of AIDS transmission through oral saliva is extremely low or almost non-existent. This phenomenon caused many AIDS experts, including Wu Zhiwei, to make bold guesses: there must be some antiviral ingredients in the mouth! When Wu Zhiwei was still working in new york University, he began to study the separation of human oral cavity and mandibular saliva. As a result, after studying the composition of saliva, they found that there are generally no live viruses in the mouth, because saliva contains several active protein that can resist HIV infection, especially a kind of protein called GP340, which can remove some bacteria in the mouth and play an important role in preventing dental caries and protecting teeth. With the deepening of research, Wu Zhiwei and others realized that the gene of this protein may play two important roles in human body: one is related to the development and differentiation of cells, and the other is related to the natural immunity of human body, which is consistent with the activity of GP340 protein in preventing cells from being infected with HIV. "We have done a lot of research work, and finally proved that GP340 can inhibit the activity of HIV-infected cells and understand its principle." Latest progress: After "Narrowing the encirclement" came to Nanjing University School of Medicine, Wu Zhiwei led the research group to continue the cooperative research with new york University on "Specific parts of protein GP340". This complete protein consists of more than 1600 amino acids. Which amino acids are at work? At the beginning of 2007, they have narrowed the encirclement, reducing the antiviral area to one tenth of that of protein, and then found that 107 amino acid may play a more important role in inhibiting HIV infection. At present, they are still continuing to determine the "minimum and necessary number of amino acids" involved in this fragment and the possible three-dimensional structure, making key preparations for the synthesis of drugs. "If you want to make a medicine, the cost will be very different if there are 1 to 2 amino acids. The fewer amino acids, the easier it is to synthesize, and strive to enter the clinic in about 3 years." So kissing is generally safe. Unless both sides have a serious oral ulcer or a deep kiss after oral surgery, only in this way can their blood come into contact with the wound and infect each other!