Central nervous system (CNS) derived human immunodeficiency virus type 1 (HIV-1) subtype C long terminal repeat (LTR) genetic and functional variation mediates high viral load in this compartment of tuberculous meningitis (TBM) co-infected patients.
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Date
2023
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Abstract
Background: Human immunodeficiency virus type 1 (HIV-1) ribonucleic acid (RNA) is
characteristically lower in the central nervous system (CNS) than in plasma of antiretroviral
treatment naïve patients. Paradoxically, there is higher HIV-1 viral load in the cerebral spinal fluid
(CSF) than plasma of treatment naïve patients co-infected with tuberculous meningitis (TBM). The
mechanisms that govern high viral replication in the CNS of TBM co-infected antiretroviral therapy
naïve patients remain to be determined.
Methodology: The study population comprised of 17 TBM and 3 non-TBM participants selected
from an HIV-1 positive and TBM co-infected cohort. The HIV-1 viral RNA was reversed
transcribed into complementary deoxyribonucleic acid (cDNA) thus the U3/R region of 3’ long
terminal repeat (LTR) was amplified from CSF and plasma RNA by KAPA HiFi HotStart PCR Kits
(ThermoFisher Scientific, Invitrogen™, USA). The patients CSF and plasma derived LTR were
subsequently cloned into a pGL3 plasmid and further transfected in Jurkat and Astrocyte cell lines
to assess the LTR transcriptional activity using Bright-Glo™ Luciferase Assay System (Promega,
Madison, WI, USA).
Results: CSF derived LTR had a significantly (p<0.0001) higher basal and Tat induced
transcriptional activity compared to plasma derived LTR in Astrocyte (SVG) cell line. Similarly,
CSF derived LTR had significantly higher (p=0.0024) Tat induced transcriptional activity compared
to plasma derived LTR in Jurkat cell lines. LTR sequences containing an Adenine (A) at position 5
of the Sp1III binding site were associated with significantly high basal (p<0.0001) and Tat induced
(p=0.0002) transcriptional activity compared to the LTR sequences containing a Thymine (T) at the
same position when it was assessed in SVG cell. A similar case was observed in Jurkat cell lines.
Consistently, CSF LTR sequences containing an A at position 5 of the Sp1III transcription binding
site were associated with significantly higher HIV-1 viral load compared to LTR sequences
containing a T at the same position (p=0.0093).
Conclusion: Our data clearly show that CSF derived LTR from TBM co-infected individuals
exhibit significantly higher transcriptional. Particularly, sequences containing the A5T mutation
are significantly associated with higher LTR transcriptional activity and viral load.
Description
Masters Degree. University of KwaZulu-Natal, Durban.