Frontiers in Immunology (Nov 2021)

Splenic Transcriptional Responses in Severe Visceral Leishmaniasis: Impaired Leukocyte Chemotaxis and Cell Cycle Arrest

  • Caroline Vilas Boas de Melo,
  • Felipe Guimarães Torres,
  • Micely D’El-Rei Hermida,
  • Jonathan L. M. Fontes,
  • Bianca Ramos Mesquita,
  • Reginaldo Brito,
  • Pablo Ivan P. Ramos,
  • Gabriel R. Fernandes,
  • Luiz Antônio Rodrigues Freitas,
  • Ricardo Khouri,
  • Carlos Henrique Nery Costa,
  • Washington L. C. dos-Santos

DOI
https://doi.org/10.3389/fimmu.2021.716314
Journal volume & issue
Vol. 12

Abstract

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Structural changes in the spleen have been reported in several infectious diseases. In visceral leishmaniasis (VL), a severe parasitic disease caused by Leishmania spp., the loss of white pulp accompanies a severe clinical presentation. Hamster model reproduces aspects of human VL progression. In the early stages, a transcriptomic signature of leukocyte recruitment was associated with white pulp hyperplasia. Subsequently, impaired leukocyte chemotaxis with loss of T lymphocytes in the periarteriolar lymphoid sheath occurred. This differential gene expression was subsequently corroborated by transcriptomic profiling of spleens in severe human VL. At the latest stage, spleen disorganization was associated with increasing clinical signs of VL. White pulp disruption was accompanied by decreased DLK1 expression. The expression of CXCL13, CCR5, CCL19, CCR6, CCR7 and LTA decreased, likely regulated by CDKN2A overexpression. Our findings enlighten a pathway implying cell cycle arrest and decreased gene expression involved in spleen organization.

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