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

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 anti-cryptococcal defences with an overall pro-cryptococcus 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/JJHAN HHV-6 co-cultures were exposed to Cryptococcus neoformans for 2, 3, 4 and 6 h. The co-cultures showed negative levels of anti-cryptococcal activity that were more marked for THP1/JJHAN HHV-6 at 6 h. The results demonstrated that macrophages exposed to HHV-6 have reduced anti-cryptococcal activity.