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Updated: Sep 25, 2026
Obtaining Human Microglia from Adult Human Brain Tissue
Published on: August 30, 2020
Human microglial cell isolation from adult autopsy brain: brain pH, regional variation, and infection with human
Kimberly Schuenke1, Benjamin B Gelman
1Department of Pathology, The University of Texas Medical Branch, Galveston, Texas 77555-0609, USA. kischuen@utmb.edu
Abstract:
Microglia are the main source of productive infection by human immunodeficiency virus type 1 (HIV-1) in the central nervous system (CNS). Infection of microglia is difficult to study because nonhuman microglia are not infected by HIV-1, adult human microglia from surgically removed brain tissues are scarce, and fetal human microglial cells differ from adult cells in potentially important ways. Adult autopsies are a potential source of brain tissue for HIV-1 research, but the technique of isolating and infecting cells postmortem is not completely standardized. The authors determined optimal conditions for isolating and infecting adult microglial cells using 18 adult autopsy brain specimens from HIV-1-infected and noninfected decedents. The yield of mixed glial cells overall was on average 0.5 x 10(6) cells per gram of wet tissue. There was no correlation between the number of microglia isolated and the postmortem interval (PMI), HIV seropositivity, age, or gender. Brain pH accounted for about 41% of yield variability; a pH of less than 6.0 generally was not compatible with adequate cell recovery. The highest microglial cell yields were derived from anterior brain sectors (frontal lobe and temporal lobe) versus occipital lobe and cerebellum. A PMI of up to 25.5 h produced excellent cell yields in frontal lobe samples with high brain pH. HIV-1 infection of frontal lobe microglia was 100% successful using both CXCR4- and CCR5-tropic strains of HIV-1. With proper selection of cases and brain region, autopsy brain specimens are a dependable source of viable microglial cells to study CNS HIV-1 infection.
Insights
Researchers optimized methods for isolating and infecting adult human microglia from autopsy brains for studying human immunodeficiency virus type 1 (HIV-1) central nervous system (CNS) infection. Autopsy brain tissue is a viable source for this critical HIV-1 research.
Area of Science:
- Neuroscience
- Virology
- Immunology
Background:
- Microglia are the primary cells infected by human immunodeficiency virus type 1 (HIV-1) in the central nervous system (CNS).
- Studying HIV-1 infection in microglia is challenging due to limited availability of adult human microglia and differences in fetal cells.
- Adult autopsy brain tissue offers a potential source for microglia, but isolation and infection protocols require standardization.
Purpose of the Study:
- To determine optimal conditions for isolating and infecting adult human microglial cells from autopsy brain specimens.
- To establish a reliable method for obtaining viable microglia for studying CNS HIV-1 infection.
Main Methods:
- Analyzed 18 adult autopsy brain specimens from HIV-1-infected and non-infected individuals.
- Assessed factors influencing microglial yield, including postmortem interval (PMI), HIV serostatus, age, gender, and brain pH.
- Optimized isolation techniques focusing on brain region and pH, and tested HIV-1 infection efficiency in isolated microglia.
Main Results:
- Microglial yield was not correlated with PMI, HIV status, age, or gender, but was significantly affected by brain pH (optimal > 6.0).
- Anterior brain regions (frontal and temporal lobes) yielded more microglia than posterior regions.
- Up to 25.5 hours postmortem interval (PMI) with high brain pH in frontal lobe samples yielded excellent cell recovery, with 100% HIV-1 infection success.
Conclusions:
- Adult autopsy brain specimens, when selected carefully based on brain region and pH, are a dependable source of viable microglia.
- Standardized isolation and infection protocols using autopsy-derived microglia enable effective study of CNS HIV-1 infection.
- This research provides a crucial method for advancing our understanding of HIV-1 neuropathogenesis.
