Journal: bioRxiv
Article Title: Elucidating genes sufficient for viral entry into cells through sequential genome-wide CRISPR activation screens
doi: 10.64898/2026.03.06.710083
Figure Lengend Snippet: A) NGFR was expressed in Jurkat C6 cells using CRISPRa, or alternatively, Jurkat cells using cDNA expression. NGFR -expressing or control cells were then inoculated with rabies pseudovirus encoding mCD19t. Flow cytometry was then performed to determine the percentage of infected cells. This revealed that NGFR expression significantly increased the susceptibility of Jurkat cells to rabies pseudovirus infection. As positive controls, flow cytometry was used to confirm successful delivery of the sgRNA construct as part of the CRISPRa workflow (as denoted by BFP expression) and that NGFR was expressed (upon cDNA expression). B) L-SIGN or DC-SIGN were expressed in primary human CD4 + T cells using cDNA expression. L-SIGN -expressing, DC-SIGN -expressing, or control cells were inoculated with rabies pseudovirus encoding hEGFRt (a truncated mutant of human EGFR). Flow cytometry was then performed to determine the percentage of infected cells. This revealed that L-SIGN or DC-SIGN expression significantly increased the susceptibility of Jurkat cells and primary T cells to Ebola pseudovirus infection. Cells expressing the highest levels of L-SIGN and DC-SIGN were preferentially infected by Ebola pseudovirus. C) L-SIGN or DC-SIGN were expressed in primary human CD4 + T cells using cDNA expression, and then L-SIGN -expressing, DC-SIGN -expressing, or control cells were inoculated with GFP -expressing Ebola virus or zsGreen -expressing Sudan virus under BSL4 containment. On days 0, 1, and 2 post-infection, flow cytometry was performed to determine the percentage of infected cells and qPCR was performed on cell culture supernatants to quantify viral genome replication. This revealed that L-SIGN or DC-SIGN expression enabled authentic Ebola and Sudan virus entry into primary human T cells, but viral genome replication was impaired, perhaps reflective of cell-intrinsic restriction factors.
Article Snippet: To achieve CRISPRa-mediated overexpression, sgRNA sequences were cloned into the lentiviral sgRNA library backbone plasmid (Addgene, 84832) using the restriction sites BstX1 and BlpI.
Techniques: Expressing, Control, Flow Cytometry, Infection, Construct, Mutagenesis, Virus, Cell Culture