Oral Presentation Australasian Cytometry Society 43rd Annual Conference and Workshop

High levels of HIV RNA transcripts in CSF cells, despite fully suppressive antiretroviral therapy (ART), are linked to brain injury (#24)

John Zaunders 1 , Kazuo Suzuki 1 , Angelique Levert-Mignon 1 , Shannen Butterly 1 , Zhixin Liu 2 , Takaomi Ishida 3 , Chin-Shiou Huang 4 , Thomas Gates 5 , Caroline Rae 6 , Lauriane Jugé 6 , Lucette A Cysique 5 , Bruce J Brew 5
  1. Centre for Applied Medical Research, St Vincent's Hospital, Darlinghurst, NSW, Australia
  2. Stats Central, UNSW, Sydney
  3. Denka Co Ltd, Tokyo, Japan
  4. PlexBio, Taipei, Taiwan
  5. Depts of Neurology and Immunology, Peter Duncan Neurosciences Unit , St Vincent’s Hospital, Sydney
  6. Neuroscience Research Australia , Sydney

Background:

HIV associated neurocognitive disorder (HAND) persists despite suppressive ART, and we aimed to study HIV RNA transcripts in CSF cells and characterize CD4 T cells that may contribute to this CNS HIV reservoir, using high-dimensional flow cytometry and our highly-sensitive Double-R assay of HIV RNA transcripts.

Methods:

CSF cells and PBMC were compared by 18-colour flow cytometry. DNA and RNA were extracted in 20 paired samples of CSF and blood from HIV+ subjects on fully suppressive ART. HIV-1 transcripts and DNA were determined by the Double-R πCode MicroDiscs assay, as copies/106 CD4. In vivo Magnetic Resonance spectroscopy measured major neuronal metabolites in the frontal white matter (FWM) and posterior cingulate cortex (PCC).

Results:

CSF cells were 91% memory T cells, comprised equally of memory CD4 (median 3,605 cells recovered) and CD8 T cells (3,507). Other CSF cells were 3.1% CD14+CD16+ monocytes, 2.0% NK cells and 0.4 % B cells. Memory CXCR3+CD49d+integrinß7- cells were 76% of CD4 T cells in CSF (vs 17% in PBMC); 51% were CCR5+ (vs 16%); and 18% expressed CD38 and/or HLA-DR activation markers (vs 11%). 18/20 patients’ CSF cells had significantly higher cell-associated HIV-1 RNA transcripts vs PBMCs (8,331 vs 680; p<0.0001), but levels were significantly correlated between CSF cells and PBMC (r=0.46; p=0.029). 16/20 patients also had significantly higher HIV-1 DNA levels in CSF cells vs PBMC (median 3,940 copies/106 cells vs 885; p<0.0001). CSF transcripts were inversely correlated with the neuronal integrity biomarker N-acetyl aspartate in FWM (p=0.04) and PCC (p=0.055).

Conclusion:

CSF cells have high HIV RNA transcriptional activity despite ART, most likely in the predominant CXCR3+CD49d+integrinß7-CCR5+ memory CD4+T cells. Ligands for CXCR3+ cells, especially IP-10, likely induce trafficking of circulating infected CD4 T cells into the CNS. Therapies targeting transcription should be developed, to reduce compromised neuron integrity.