Some innovative facts about human cytomegalovirus and news

 

      A cytomegalovirus is a herpersvirus that in healthy individuals causes an infection that is asymptomatic or is accompanied by mild symptoms (such as fever or fatigue) but in immunocompromised individuals and new borns may cause an infection marked by serious, sometimes life-threatening symptoms such as: pneumonia, hepatitis, retinitis, brain inflammation, or seizures. A cytomegalovirus is a virus with double stranded DNA.

      A herpesvirus is any of a family (Herpesviridae) of double-stranded DNA viruses that include the cytomegalovirus and the causative agents of chicken pox, Epstein-Barr virus and herpes simplex, roseola infantum, Marek's disease, and shingles, as well as many other viruses to be said about with.

      Human cytomegalovirus (CMV) is a highly prevalent herpesvirus that is often transmitted to the neonate via breast milk from the mother to the child. Postnatal CMV transmission can have, allegedly, negative health consequences for preterm born and immunocompromised infants, but any effects on healthy term infants are thought to be benign. It is important to utilize a cohort of exclusively breastfeeding full term mother-infant pairs to test for differences in the milk transcriptome and metabolome associated with CMV, and the impact of CMV in breast milk on the infant gut microbiome and infant growth.

      We find upregulation of the indoleamine 2,3-dioxygenase (IDO) tryptophan-to-kynurenine metabolic pathway in CMV+ milk samples, and that CMV+ milk is associated with decreased bifidobacterium in the infant gut. Herpesviruses assemble large enveloped particles that are difficult to characterize structurally due to their size, fragility and complex multi-layered proteome with partially amorphous nature. The structured assembly of infectious particles, called virions, is fundamental for virus transmission among cells and organisms. Virions contain the viral nucleic acid genome enclosed in a capsid protein shell.

      Herpesviruses, a family of double-stranded DNA viruses, assemble particularly large and complex particles, accommodating many different proteins that are delivered to the host cell upon infection. A multitude of co-packaged proteins facilitate the infection process and the onset of viral gene expression. The capacity of herpesvirions to incorporate a large set of proteins is enabled by their typical multilayered architecture. The outer lipid envelope harbours various viral glycoproteins required for host cell receptor binding and membrane fusion. The space between the envelope and the central icosahedral nucleocapsid is filled with a proteinaceous matrix. Herpesvirus particles also incorporate numerous host proteins, but very few of these events have been functionally or mechanistically characterized by the humans which somewhat are from and live on the surface of this planet Earth.

      Recent cryogenic electron microscopy (cryoEM) studies of herpesvirions by a group of researchers from Earth have revealed substructures of the nucleocapsid and several glycoprotein complexes. They have also isolated extracellular particles from infectious cell culture supernatant and crosslinked them with disuccinimidyl sulfoxide (DSSO), which connects lysines from proteins in close spatial proximity. After purification of the crosslinked virions trough tartrate-glycerol density gradient centrifugation, protein extraction and tryptic digestion, the crosslinked peptides were identified by liquid chromatography mass spectrometry (LC–MS). We evaluated the quality of the preparations by performing negative-staining electron microscopy on crosslinked and/or gradient-purified particles.

 

Reference

https://www.nature.com/articles/s41564-023-01433-8