Simple assay system for detecting human T cell leukemia virus type I-binding cells and its application in titrating binding inhibitory antibodies.
BACKGROUND
A simple and rapid assay system for the detection of human T cell leukemia virus type I (HTLV-I) binding cells was developed to assess the virus specific receptor and titrate the antibodies to block the virus binding.


METHODS
Cells (5 x 10(5)) were incubated with 100 microliters of the concentrated HTLV-I at 37 degrees C for 1 hour. After washing, the cells were reacted with anti-HTLV-I envelope monoclonal antibody (rat) for 30 minutes on ice and then stained with fluorescein-isothiocyanate-conjugated anti-rat immunoglobulin. The stained samples were analyzed on FACScan. Antibody-titration of the virus-binding inhibition was carried out by pretreatment of the virus with serially diluted sera.


RESULTS
The specificity of the virus-binding was shown by dose-response relationship, kinetics of the binding, and temperature dependency. HTLV-I was absorbed onto a wide range of human cell lines and peripheral blood lymphocytes at various levels. Antibodies to inhibit the virus-binding were also quantitatively detected in sera from HTLV-I infected individuals, including asymptomatic carriers and patients with adult T cell leukemia or HTLV-I-associated myelopathy, but not from healthy seronegative controls.


CONCLUSIONS
This assay system would be useful in screening the virus-specific receptor and the neutralizing antibodies to HTLV-I. Thus, the assay could be applied to further studies on HTLV-I-related diseases.
Akari
H
H
Department of Biodefence and Medical Virology, Kumamoto University School of Medicine, Japan.
Kannagi
M
M
Shinjo
T
T
Harada
S
S
D000911:Antibodies, Monoclonal; D002051:Burkitt Lymphoma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D002460:Cell Line; D015481:HTLV-I Antibodies / Q000032:analysis* / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism* / Q000473:pathology*; D015470:Leukemia, Myeloid, Acute / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D008223:Lymphoma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D008722:Methods; D011991:Receptors, Virus / Q000032:analysis* / Q000037:antagonists & inhibitors*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism*; D017186:Titrimetry / Q000379:methods; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D015481:HTLV-I Antibodies; D011991:Receptors, Virus