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Wolbachia surface protein (WSP) inhibits apoptosis in human neutrophils

C Bazzocchi1, S Comazzi, R Santoni

  • 1Dipartimento di Patologia Animale Igiene e Sanità Pubblica Veterinaria, Sezione di Patologia Generale e Parassitologia, Università di Milano, Milano, Italy.

Parasite Immunology
|January 24, 2007
PubMed

Insights

The Wolbachia surface protein (WSP) inhibits programmed cell death in human immune cells. This discovery sheds light on bacterial pathogenesis and immune evasion strategies employed by Wolbachia.

Area of Science:

  • Immunology
  • Microbiology
  • Cell Biology

Background:

  • Polymorphonuclear cells (PMNs) are critical for innate immunity against bacterial infections.
  • Bacterial manipulation of PMN apoptosis is a key pathogenic mechanism.
  • Wolbachia bacteria, endosymbionts of filarial nematodes, are phylogenetically linked to Anaplasmataceae.

Purpose of the Study:

  • To investigate the role of Wolbachia surface protein (WSP) in modulating human PMN apoptosis.
  • To provide the first evidence of anti-apoptotic activity by a Wolbachia surface protein.

Main Methods:

  • Purified human PMNs were stimulated with WSP in vitro.
  • TUNEL assay was used to quantify cell death.
  • Annexin V-FITC binding assay differentiated apoptosis from necrosis.
  • Caspase-3 activity was measured to confirm apoptosis inhibition.

Main Results:

  • WSP stimulation significantly reduced the percentage of dead cells in human PMNs.
  • Annexin V-FITC assays indicated that cell death was primarily apoptotic.
  • Caspase-3 activity was reduced in WSP-stimulated cells, confirming apoptosis inhibition.

Conclusions:

  • The Wolbachia surface protein (WSP) exhibits anti-apoptotic activity on human PMNs.
  • WSP may represent a novel mechanism for bacterial immune evasion.
  • This finding contributes to understanding the pathogenesis of Wolbachia-associated infections.

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