In:
British Journal of Haematology, Wiley, Vol. 197, No. 3 ( 2022-05), p. 283-292
Abstract:
Severe COVID‐19 is associated with a systemic inflammatory response and progressive CD4 + T‐cell lymphopenia and dysfunction. We evaluated whether platelets might contribute to CD4 + T‐cell dysfunction in COVID‐19. We observed a high frequency of CD4 + T cell–platelet aggregates in COVID‐19 inpatients that inversely correlated with lymphocyte counts. Platelets from COVID‐19 inpatients but not from healthy donors (HD) inhibited the upregulation of CD25 expression and tumour necrosis factor (TNF)‐α production by CD4 + T cells. In addition, interferon (IFN)‐γ production was increased by platelets from HD but not from COVID‐19 inpatients. A high expression of PD‐L1 was found in platelets from COVID‐19 patients to be inversely correlated with IFN‐γ production by activated CD4 + T cells cocultured with platelets. We also found that a PD‐L1‐blocking antibody significantly restored platelets’ ability to stimulate IFN‐γ production by CD4 + T cells. Our study suggests that platelets might contribute to disease progression in COVID‐19 not only by promoting thrombotic and inflammatory events, but also by affecting CD4 + T cells functionality.
Type of Medium:
Online Resource
ISSN:
0007-1048
,
1365-2141
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
1475751-5
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