Korean J Parasitol.  2017 Oct;55(5):491-503. 10.3347/kjp.2017.55.5.491.

Suppressors for Human Epidermal Growth Factor Receptor 2/4 (HER2/4): A New Family of Anti-Toxoplasmic Agents in ARPE-19 Cells

• Kim YH
• Bhatt L
• Ahn HJ
• Yang Z
• Lee WK
• Nam HW

• KMID: 2395753
• DOI: http://doi.org/10.3347/kjp.2017.55.5.491

Abstract

The effects of tyrosine kinase inhibitors (TKIs) were evaluated on growth inhibition of intracellular Toxoplasma gondii in host ARPE-19 cells. The number of tachyzoites per parasitophorous vacuolar membrane (PVM) was counted after treatment with TKIs. T. gondii protein expression was assessed by western blot. Immunofluorescence assay was performed using Programmed Cell Death 4 (PDCD4) and T. gondii GRA3 antibodies. The TKIs were divided into 3 groups; non-epidermal growth factor receptor (non-EGFR), anti-human EGFR 2 (anti-HER2), and anti-HER2/4 TKIs, respectively. Group I TKIs (nintedanib, AZD9291, and sunitinib) were unable to inhibit proliferation without destroying host cells. Group II TKIs (lapatinib, gefitinib, erlotinib, and AG1478) inhibited proliferation up to 98% equivalent to control pyrimethamine (5 μM) at 20 μM and higher, without affecting host cells. Group III TKIs (neratinib, dacomitinib, afatinib, and pelitinib) inhibited proliferation up to 98% equivalent to pyrimethamine at 1-5 μM, but host cells were destroyed at 10-20 μM. In Group I, TgHSP90 and SAG1 inhibitions were weak, and GRA3 expression was moderately inhibited. In Group II, TgHSP90 and SAG1 expressions seemed to be slightly enhanced, while GRA3 showed none to mild inhibition; however, AG1478 inhibited all proteins moderately. Protein expression was blocked in Group III, comparable to pyrimethamine. PDCD4 and GRA3 were well localized inside the nuclei in Group I, mildly disrupted in Group II, and were completely disrupted in Group III. This study suggests the possibility of a vital T. gondii TK having potential HER2/4 properties, thus anti-HER2/4 TKIs may inhibit intracellular parasite proliferation with minimal adverse effects on host cells.

Keyword

Toxoplasma gondii; intracellular; growth; inhibition; TKIs; HER2; HER2/4; ARPE-19

MeSH Terms

Antibodies
Blotting, Western
Cell Death
Epidermal Growth Factor*
Erlotinib Hydrochloride
Fluorescent Antibody Technique
Humans*
Membranes
Parasites
Protein-Tyrosine Kinases
Pyrimethamine
Receptor, Epidermal Growth Factor*
Toxoplasma
Antibodies
Epidermal Growth Factor
Erlotinib Hydrochloride
Protein-Tyrosine Kinases
Pyrimethamine
Receptor, Epidermal Growth Factor