[HTML][HTML] Adaptive and innate immune cells in fetal human cytomegalovirus-infected brains

Y Sellier, F Marliot, B Bessières, J Stirnemann… - Microorganisms, 2020 - mdpi.com
Y Sellier, F Marliot, B Bessières, J Stirnemann, F Encha-Razavi, T Guilleminot, N Haicheur…
Microorganisms, 2020mdpi.com
Background: The understanding of the pathogenesis of cytomegalovirus (CMV)-induced
fetal brain lesions is limited. We aimed to quantify adaptive and innate immune cells and
CMV-infected cells in fetal brains with various degrees of brain damage. Methods: In total,
26 archived embedded fetal brains were studied, of which 21 were CMV-infected and
classified in severely affected (n= 13) and moderately affected (n= 8), and 5 were uninfected
controls. The respective magnitude of infected cells, immune cells (CD8+, B cells, plasma …
Background
The understanding of the pathogenesis of cytomegalovirus (CMV)-induced fetal brain lesions is limited. We aimed to quantify adaptive and innate immune cells and CMV-infected cells in fetal brains with various degrees of brain damage.
Methods
In total, 26 archived embedded fetal brains were studied, of which 21 were CMV-infected and classified in severely affected (n = 13) and moderately affected (n = 8), and 5 were uninfected controls. The respective magnitude of infected cells, immune cells (CD8+, B cells, plasma cells, NK cells, and macrophages), and expression of immune checkpoint receptors (PD-1/PD-L1 and LAG-3) were measured by immunochemistry and quantified by quantitative imaging analysis.
Results
Quantities of CD8+, plasma cells, NK cells, macrophages, and HCMV+ cells and expression of PD-1/PD-L1 and LAG-3 were significantly higher in severely affected than in moderately affected brains (all p values < 0.05). A strong link between higher number of stained cells for HCMV/CD8 and PD-1 and severity of brain lesions was found by component analysis.
Conclusions
The higher expression of CD8, PD-1, and LAG-3 in severely affected brains could reflect immune exhaustion of cerebral T cells. These exhausted T cells could be ineffective in controlling viral multiplication itself, leading to more severe brain lesions. The study of the functionality of brain leucocytes ex vivo is needed to confirm this hypothesis.
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