Neuroinflammation generated by HIV-infected microglia promotes dysfunction and death of neurons in human brain organoids

Weili Kong; Julie Frouard; Guorui Xie; Michael J Corley; Ekram Helmy; Gang Zhang; Roland Schwarzer; Mauricio Montano; Peter Sohn; Nadia R Roan; Lishomwa C Ndhlovu; Li Gan; Warner C Greene

doi:10.1093/pnasnexus/pgae179

Neuroinflammation generated by HIV-infected microglia promotes dysfunction and death of neurons in human brain organoids

PNAS Nexus. 2024 Apr 29;3(5):pgae179. doi: 10.1093/pnasnexus/pgae179. eCollection 2024 May.

Authors

Weili Kong^{1

2}, Julie Frouard^{1

2

3}, Guorui Xie^{1

2

3}, Michael J Corley^{4

5}, Ekram Helmy^{1

2}, Gang Zhang^{1

2}, Roland Schwarzer^{1

2}, Mauricio Montano^{1

2}, Peter Sohn⁶, Nadia R Roan^{1

2

3}, Lishomwa C Ndhlovu^{4

5}, Li Gan^{5

7}, Warner C Greene^{1

2

8}

Affiliations

¹ Michael Hulton Center for HIV Cure Research at Gladstone, San Francisco, CA 94158, USA.
² Gladstone Institute of Virology, San Francisco, CA 94158, USA.
³ Department of Urology, University of California, San Francisco, San Francisco, CA 94143, USA.
⁴ Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA.
⁵ Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.
⁶ Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.
⁷ Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.
⁸ Departments of Medicine and Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA.

Abstract

Despite the success of combination antiretroviral therapy (ART) for individuals living with HIV, mild forms of HIV-associated neurocognitive disorder (HAND) continue to occur. Brain microglia form the principal target for HIV infection in the brain. It remains unknown how infection of these cells leads to neuroinflammation, neuronal dysfunction, and/or death observed in HAND. Utilizing two different inducible pluripotent stem cell-derived brain organoid models (cerebral and choroid plexus [ChP] organoids) containing microglia, we investigated the pathogenic changes associated with HIV infection. Infection of microglia was associated with a sharp increase in CCL2 and CXCL10 chemokine gene expression and the activation of many type I interferon stimulated genes (MX1, ISG15, ISG20, IFI27, IFITM3 and others). Production of the proinflammatory chemokines persisted at low levels after treatment of the cell cultures with ART, consistent with the persistence of mild HAND following clinical introduction of ART. Expression of multiple members of the S100 family of inflammatory genes sharply increased following HIV infection of microglia measured by single-cell RNA-seq. However, S100 gene expression was not limited to microglia but was also detected more broadly in uninfected stromal cells, mature and immature ChP cells, neural progenitor cells and importantly in bystander neurons suggesting propagation of the inflammatory response to bystander cells. Neurotransmitter transporter expression declined in uninfected neurons, accompanied by increased expression of genes promoting cellular senescence and cell death. Together, these studies underscore how an inflammatory response generated in HIV-infected microglia is propagated to multiple uninfected bystander cells ultimately resulting in the dysfunction and death of bystander neurons.

Keywords: HAND; human iPSC-derived brain organoids; inflammation; microglia; neuronal dysfunction.