Theileria parva

Reappearance of schizonts in infected lymphoblastoid cells treated with parvaquone is dependent on interleukin 2-like growth factors

Wendy C. Brown, Michael K. Shaw, Patricia A Conrad, Thomas T. Dolan

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Schizont-infected cell lines derived by in vitro infection of bovine T cell clones with the Muguga isolate of Theileria parva were treated for 72 hr with the theileriacidal drug, parvaquone, at a concentration of 10 μg/ml. This treatment completely eliminated schizonts from the recovered cells, which failed to undergo further proliferation and died. However, treated cells cultured with either bovine T cell growth factor or human recombinant interleukin 2 remained viable, underwent proliferation, and in many instances, schizonts reappeared. When cultured in the presence of supernatant obtained from an actively growing T. parva-infected cell line, treated cells did not proliferate, but schizonts reappeared. The cells became transformed by the parasite and grew continuously in the absence of exogenous growth factor. The appearance of schizonts was preceeded by the development of densely staining intracytoplasmic inclusions, visualized by light and electron microscopy. Electrondense inclusions were shown to contain DNA. Hybridization of a T. parva-specific DNA probe to Southern blots of restriction enzyme-digested DNA prepared from parvaquone-treated cells which developed inclusions but not schizonts produced a pattern similar to that seen with DNA prepared from schizont-infected cells. We conclude that reorganization of schizonts can occur in T. parva-infected T lymphocytes cured of infection with parvaquone in the presence of interleukin 2 or growth factors produced by T. parva-infected cells. The implications of these results for the establishment of a carrier state following parvaquone therapy are discussed.

Original languageEnglish (US)
Pages (from-to)308-325
Number of pages18
JournalExperimental Parasitology
Volume68
Issue number3
DOIs
StatePublished - 1989
Externally publishedYes

Fingerprint

Theileria parva
Schizonts
Interleukin-2
Intercellular Signaling Peptides and Proteins
T-Lymphocytes
Carrier State
Cell Line
parvaquone
DNA
DNA Restriction Enzymes
DNA Probes
Southern Blotting
Infection
Cultured Cells
Electron Microscopy
Parasites
Clone Cells
Staining and Labeling
Light

Keywords

  • Parvaquone
  • Theileria parva
  • Theileriosis, bovine

ASJC Scopus subject areas

  • Immunology
  • Parasitology
  • Infectious Diseases

Cite this

Theileria parva : Reappearance of schizonts in infected lymphoblastoid cells treated with parvaquone is dependent on interleukin 2-like growth factors. / Brown, Wendy C.; Shaw, Michael K.; Conrad, Patricia A; Dolan, Thomas T.

In: Experimental Parasitology, Vol. 68, No. 3, 1989, p. 308-325.

Research output: Contribution to journalArticle

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