No association between human herpesvirus 6 reactivation and cryptococcosis in human immunodeficiency virus-infected patients

Human herpesvirus 6 (HHV-6) is a part of the virus subfamily betaherpes. A recent in vitro study suggested that HHV-6 may dysregulate monocyte-mediated anticryptococcal defences with an overall procryptococcus result (Cermelli et al., 2006). Briefly, co-cultures of THP1/JJHAN cell lines were tested for anti-cryptococcal activity by c.f.u. inhibition assay. THP1/ JJHANmock and THP1/JJHANHHV-6 cocultures were exposed to Cryptococcus neoformans for 2, 3, 4 and 6 h. The cocultures showed negative levels of anticryptococcal activity that were more marked for THP1/JJHANHHV-6 at 6 h. The results demonstrated that macrophages exposed to HHV-6 have reduced anticryptococcal activity.