Biology subjects

Rasaiyaah, J.

Publications and source records attributed to Rasaiyaah, J..

3 recordsLinked to original sources

bioRxiv2022

Macrophage activation of cGAS and TRIM5 distinguish pandemic and non-pandemic HIV

Pandemic viruses remain a global threat to health and economics but how they adapt to become pandemic remains poorly understood. Here we compare pandemic HIV-1(M) and non-pandemic HIV-(O) and HIV-2 strains finding that non-pandemic HIV replicate poorly in myeloid cell models due to activation of cGAS and TRIM5, and ensuing antiviral responses. We use phylogenetics and viral capsid structural biology to define specific differences between pandemic and non-pandemic HIV capsids and demonstrate that their genetic reversal in HIV-1(M) mutants causes TRIM5, cGAS and innate immune activation. We propose a model in which the parental lineage of pandemic HIV-1(M) has uniquely evolved a dynamic capsid that avoids activation of cGAS and TRIM5 to establish cloaked replication in myeloid cells. The unique adaptations of the pandemic virus lineage suggests a role in effective human-to-human transmissibility and highlight the importance of avoiding innate immune activation during pandemic human-to-human viral transmission.

immunology↗

bioRxiv2020

Base-edited CAR T Cells for combinational therapy against T cell malignancies

Targeting T cell malignancies using chimeric antigen receptor (CAR) T cells is hindered by T v T fratricide against shared antigens such as CD3 and CD7. Genome-editing can overcome such hurdles through targeted disruption of problematic shared antigens. Base editing offers the possibility of seamless disruption of gene expression through the creation of stop codons or elimination of splice donor or acceptor sites. We describe the generation of fratricide resistant, T cells by orderly removal of shared antigens such as TCR/CD3 and CD7 ahead of lentiviral mediated expression of CARs specific for CD3 or CD7. Molecular interrogation of base edited cells confirmed virtual elimination of chromosomal translocation events detected in conventional Cas9 treated cells. Interestingly, co-culture of 3CAR and 7CAR cells resulted in self-enrichment yielding populations that were 99.6% TCR-/CD3/-CD7-. 3CAR or 7CAR cells were able to exert specific cytotoxicity against their relevant target antigen in leukaemia lines with defined CD3 and/or CD7 expression as well as primary T-ALL cells. Co-cultured 3CAR/7CAR cells exhibited the highest level of cytotoxicity against T-ALL targets expressing both target in vitro and an in vivo human:murine chimeric model. While APOBEC editors can reportedly exhibit guide-independent deamination of both DNA and RNA, we found no evidence of promiscuous base conversion activity affecting CAR antigen specific binding regions which may otherwise redirect T cell specificity. Combinational infusion of fratricide resistant anti-T CAR T cells may enable enhanced molecular remission ahead of allogeneic haematopoietic stem cell transplantation for T cell malignancies.

molecular biology↗

bioRxiv2020

HIV-1 Vpr antagonizes cGAS sensing by targeting karyopherin-mediated NF-κB/IRF3 nuclear transport

HIV-1 must replicate in cells that are equipped to defend themselves from infection through intracellular innate immune systems. HIV-1 evades innate immune sensing through encapsidated DNA synthesis and encodes accessory genes that antagonize specific antiviral effectors. Here we show that both particle associated, and expressed HIV-1 Vpr, antagonize the stimulatory effect of a variety of pathogen associated molecular patterns by inhibiting IRF3 and NF-κB nuclear transport. Phosphorylation of IRF3 at S396, but not S386, was also inhibited. We propose that, rather than promoting HIV-1 nuclear import, Vpr interacts with karyopherins to disturb their import of IRF3 and NF-κB to promote replication in macrophages. Concordantly, we demonstrate Vpr dependent rescue of HIV-1 replication in human macrophages from inhibition by cGAMP, the product of activated cGAS. We propose a model that unifies Vpr manipulation of nuclear import and inhibition of innate immune activation to promote HIV-1 replication and transmission.Competing Interest StatementThe authors have declared no competing interest.View Full Text

microbiology↗