Effects of human serum on Balamuthia mandrillaris interactions with human brain microvascular endothelial cells

Abdul Matin, Seok Ryoul Jeong, Monique Stins, Naveed Ahmed Khan

Research output: Contribution to journalArticle

Abstract

Balamuthia mandrillaris is a free-living amoeba and a causative agent of fatal granulomatous encephalitis. In the transmission of B. mandrillaris into the central nervous system (CNS), haematogenous spread is thought to be the primary step, followed by blood-brain barrier penetration. The objectives of the present study were (i) to determine the effects of serum from healthy individuals on the viability of B. mandrillaris, and (ii) to determine the effects of serum on B. mandrillaris-mediated blood-brain barrier perturbations. It was determined that normal human serum exhibited limited amoebicidal effects, i.e. ∼0% of trophozoites were killed. The residual subpopulation, although viable, remained static over longer incubations. Using human brain microvascular endothelial cells (HBMEC), which form the blood-brain barrier, it was observed that B. mandrillaris exhibited binding (> 80%) and cytotoxicity (> 70%) to HBMEC. However, normal human serum exhibited more than 60% inhibition of B. mandrillaris binding and cytotoxicity to HBMEC. ELISAs showed that both serum and saliva samples exhibit the presence of anti-B. mandrillaris antibodies. Western blots revealed that normal human serum reacted with several B. mandrillaris antigens with approximate molecular masses of 148, 115, 82, 67, 60, 56, 44, 42, 40 and 37 kDa. Overall, the results demonstrated that normal human serum has inhibitory effects on B. mandrillaris growth and viability, as well as on their binding and subsequent cytotoxicity to HBMEC. A complete understanding of B. mandrillaris pathogenesis is crucial to develop therapeutic interventions and/or to design preventative measures.

Original languageEnglish (US)
Pages (from-to)30-35
Number of pages6
JournalJournal of Medical Microbiology
Volume56
Issue number1
DOIs
StatePublished - Jan 1 2007

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ASJC Scopus subject areas

  • Microbiology
  • Microbiology (medical)

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