Retinal pigment epithelial cell infection with human T-cell leukemia virus type 1 is inhibited by an ICAM-1 neutralizing antibody

11-21-2006

In a recent report published in the journal Investigative Ophthalmology & Visual Science, researchers in the United States conducted a study to "examine whether human T-cell leukemia virus type 1 (HTLV-1) could infect a human retinal pigment epithelial (RPE) cell Line, ARPE-19, in vitro and to investigate its regulation.

"A coculture system with ARPE-19 and irradiated cells of an HTLV-1-producing T-cell line, MT2 was used to determine the permissivity of RPE to HTLV-I infection in vitro."

"The susceptibility to HTLV-1 was assessed by detection of viral DNA using the polymerase chain reaction (PCR), viral mRNA transcripts with reverse transcription PCR (RT-PCR) and viral antigen by immunofluorescence staining. An HTLV-1 Tax-activated HTLV-LTR-luciferase reporter assay was developed to measure viral infection quantitatively.

"The ICAM-1 expression on cocultured ARPE-19 cells was detected by flow cytometry and an ICAM-1-neutralizing antibody was used to test ICAM-1's role in the HTLV-1 infection of ARPE-19 cells. The regulation of HTLV-1 infection was investigated by culturing ARPE-19 cells with proinflammatory cytokines," said B.Y. Liu and colleagues at the U.S. National Institutes of Health.

According to the authors, "HTLV-1 infected ARPE-19 cells in vitro. The infection correlated with elevated expression of intercellular adhesion molecule (ICAM)-1 on the surface of ARPE-19 cells. ICAM-1-neutralizing antibody dramatically inhibited viral infection. Furthermore, proinflammatory cytokines dramatically suppressed HTLV-1 viral infection."

"The tropism of HTLV-1 to retinal pigment epithelium could provide an explanation for the pathogenesis of HTLV-1-related ophthalmic diseases. A better Understanding of specific roles of proinflammatory cytokines in the development of ophthalmic diseases may be beneficial for treatment," concluded Liu.

Liu and colleagues published their study in Investigative Ophthalmology & Visual Science (HTLV-1 infection of human retinal pigment epithelial cells and inhibition of viral infection by an antibody to ICAM-1. Invest Ophthalmol Vis Sci, 2006;47(4):1510-1515).

For additional information, contact R.B. Nussenblatt, NEI, Immunology Laboratory, NIH, Bethesda, MD 20892, USA.