Infection of U87-CD4 cells using ViroMag R/L

As previously described in their previous paper (Berro et al, J Virol. 2011 Aug;85(16):8227-40.), the authors used ViroMag R/L to infect U87-CD4 cells with envelopped pseudoviruses.

This paper shows the efficiency of ViroMag R/L from OZ Biosciences to infect U87-CD4 cells with envelopped-pseudoviruses.

article reference: J Virol. 2013 Mar 6.

Use of G-protein coupled and uncoupled CCR5 receptors by CCR5 inhibitor-resistant and -sensitive human immunodeficiency virus type 1 variants.

Berro R, Yasmeen A, Abrol R, Trzaskowski B, Abi-Habib S, Grunbeck A, Lascano D, Goddard WA 3rd, Klasse PJ, Sakmar TP, Moore JP.

Abstract

Small molecule CCR5 inhibitors such as Vicriviroc (VVC) and Maraviroc (MVC) are allosteric modulators that impair HIV-1 entry by stabilizing a CCR5 conformation the virus recognizes inefficiently. Viruses resistant to these compounds are able to bind the inhibitor-CCR5 complex, while also interacting with the free co-receptor. CCR5 also interacts intracellularly with G-proteins as part of its signal transduction functions, a process that alters its conformation. Here, we investigated whether the action of VVC against inhibitor-sensitive and -resistant viruses is affected by whether or not CCR5 is coupled to G-proteins such as Gα_i. Treating CD4⁺ T cells with pertussis toxin to uncouple the Gα_i subunit from CCR5 increased the potency of VVC against the sensitive viruses and revealed that VVC-resistant viruses use the inhibitor-bound form of Gα_i-coupled CCR5 more efficiently than uncoupled CCR5. Supportive evidence was obtained by expressing a signaling-deficient CCR5 mutant with an impaired ability to bind to G-proteins, and also two constitutively active mutants that activate G-proteins in the absence of external stimuli. The implication of these various studies is that the association of intracellular domains of CCR5 with the signaling machinery affects the conformation of the external and transmembrane domains, and how they interact with small molecule inhibitors of HIV-1 entry.

ViroMag R/L from OZ Biosciences is a magnetic nanoparticles formulation optimized for increasing any kind of virus infection and transduction both in vitro and in vivo.