Dendritic cells (DCs) play a central role in initiating immune responses. Some persistent viruses infect DCs and can disrupt their functions in vitro. However, these viruses remain strongly immunogenic in vivo. Thus what role DC infection plays in the pathogenesis of persistent infections is unclear. Here we show that a persistent, B cell-tropic gamma-herpesvirus, Murid Herpesvirus-4 (MuHV-4), infects DCs early after host entry, before it establishes a substantial infection of B cells. DC-specific virus marking by cre-lox recombination revealed that a significant fraction of the virus latent in B cells had passed through a DC, and a virus attenuated for replication in DCs was impaired in B cell colonization. In vitro MuHV-4 dramatically altered the DC cytoskeleton, suggesting that it manipulates DC migration and shape in order to spread. MuHV-4 therefore uses DCs to colonize B cells.

Graphical abstract

The fascinating discovery of first giant virus, Acanthamoeba polyphaga mimivirus (APMV) belonging to family Mimiviridae in 2008 and its associated virophage Sputnik have left the world of microbiology awestruck. Till date about 18 virophages has been isolated from different environmental sources. With its unique feature of resisting host cell infection and lysis by giant viruses, analogous to bacteriophage, they have been assigned under family Lavidaviridae. Genome of T-27 icosahedral shaped, non-enveloped virophages consists of dsDNA encoding four proteins like major capsid protein, minor capsid protein, ATPase and cysteine protease that are essential in formation and assembly of new virophage particles during replication. Few virophage genome has been observed to contain additional sequences like PolB, ZnR and S3H. Another interesting character of virophage is that Mimivirus lineage A is immune to infection by Zamilon virophage through a phenomenon termed as MIMIVIRE, resembling CRISPR-Cas mechanism in bacteria. Based on the fact that giant viruses have been found in clinical samples of hospital acquired pneumonia and rheumatoid arthritis patients, virophages can be imagined to have opened a novel era in the search for cure of various diseases. This article aims to study the prospective role of virophages in the future of human therapeutics.

No abstract

Co-endemicity of SARS-CoV-2 and dengue virus (DV) infection is becoming a matter of serious concern as it has been already reported that antibodies (Ab) elicited by SARS-CoV-2 infection can produce false-positive results in dengue IgG and IgM rapid tests and vice versa. Here we communicate that five of thirteen DV antibody-positive serum samples from Kolkata, archived in 2017 (predating the COVID-19 outbreak), produced false-positive results in SARS-CoV-2 IgG/IgM lateral flow-based rapid tests. Our results emphasize the importance of implementing tests with higher specificity to conduct sero-surveillance for accurate estimation of SARS-CoV-2/DV prevalence in regions where both viruses now co-exist.