Human herpesvirus-6 dysregulates monocyte-mediated anticryptococcal defences.
In order to investigate the interplay occurring between pathogens in the course of double infections, an in vitro model was set up in which the monocytic cell line THP-1 was exposed to Cryptococcus neoformans (Cn) and human herpesvirus 6 (HHV-6). Cn and HHV-6, both highly neurotropic, can cause serious diseases of the central nervous system and have monocytes, among other cell types, as target cells, causing alteration of their secretion pattern. Here, it was shown that unlike THP-1 cells exposed to cell-free virus inocula, THP-1 exposed to HHV-6-producing lymphocytes exhibited augmented phagocytosis against Cn. The phenomenon occurred after 24 h of monocyte/lymphocyte co-culture and was independent of direct cell-to-cell contact. Moreover, in the presence of HHV-6, THP-1 cells expressed enhanced secretory responses but reduced capability to counteract fungal infection: the enhanced ingestion by monocytes was followed by facilitated fungal survival and replication. These data provide initial in vitro evidence that HHV-6 may dysregulate monocyte-mediated anticryptococcal defences with an overall pro-cryptococcus result.
Cermelli
Claudio
C
Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Via Campi 287, I-41100 Modena, Italy.
Cenacchi
Valeria
V
Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Via Campi 287, I-41100 Modena, Italy.
Beretti
Francesca
F
Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Via Campi 287, I-41100 Modena, Italy.
Pezzini
Francesco
F
Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Via Campi 287, I-41100 Modena, Italy.
Luca
Dario Di
DD
Department of Experimental and Diagnostic Medicine, University of Ferrara, Ferrara, Italy.
Blasi
Elisabetta
E
Department of Hygiene, Microbiology and Biostatistics, University of Modena and Reggio Emilia, Via Campi 287, I-41100 Modena, Italy.