THE USE OF SERUM-FREE MEDIUM DELAYS, BUT DOES NOT PREVENT, THE CYTOTOXIC EFFECTS OF SEMINAL PLASMA IN LYMPHOCYTE-CULTURES - IMPLICATIONS FOR STUDIES ON HIV-INFECTION

Evidence indicates that seminal plasma is cytotoxic when used in lymph ocyte cultures. In fact, an amine oxidase which is normally present in Fetal Calf Serum (FCS) causes spermine oxidation and, finally, cytoto xic substances are released. This seminal quality might obviously hamp er studies aiming to evaluate the role of semen in HIV sexual transmis sion, since lymphocytes are generally used as target or effector cells in virological or immunological studies on HIV.We evaluated the effic acy of FCS free-medium, heat inactivated seminal plasma and/or the was hing-out of cultures after a three hour incubation period in preventin g the cytotoxicity to lymphocytes. Results show that when cultures are carried out in the absence of FCS and/or after seminal plasma removal , cytotoxicity is not prevented, although delayed. This finding indica tes that, along with still unrecognized additional factors, spermine o xidation is still an important factor for semen cytotoxicity, and this considerably hampers any immunological and virological study, requiri ng the use of lymphocytes, concerning seminal fluid.