Improvement of simultaneous detection of antibodies to Gag and envelope antigens of human T-lymphotropic virus type I by western immunoblot assay

Abstract

To determine seropositivity for human T-lymphotropic virus type I (HTLV-I), we attempted to improve the detection system that uses antibody to HTLV-I Env in Western immunoblotting (WB) by adding an envelope glycoprotein (gp46) purified from the culture fluid of HTLV-I-producing cells by immunoaffinity chromatography and gel chromatography. In this VB, 177 of 179 serum samples showing seropositivity in an indirect immunofluorescence assay showed positive reactions to the gp46 envelope antigen as well as to p19, p24, and p53 Gag antigens. The remaining two samples showed negative reactions to p24. False-positive results were not found for 533 indirect immunofluorescence assay-negative serum samples, although one band to p19 or p24 was observed in 46 of the 533 samples. These 46 samples did not react to p53 and gp46, suggesting that these samples belonged to the indeterminate group in accordance with the criteria proposed by the World Health Organization. Therefore, this improved WB can be used for the confirmation of seropositivity.

Analysis of HTLV‐1 proviral load (PVL) and antibody detected with various kinds of tests in Japanese blood donors to understand the relationship between PVL and antibody level and to gain insights toward better antibody testing

“…This discrepancy may arise from a loss of sufficiently intact envelope glycoproteins during the purification of the virus fraction from cell lysates. 32,33 Therefore, the CL4800 testing system and CLEIA may not have been as sensitive to anti-Env antibodies. While most HTLV-1 carriers have antibodies to Gag and Env antigens, 34 it is nonetheless possible that a few carriers may lack antibodies to one or the other of these two antigens.…”

Trypsin-sensitive and -resistant components in human T-cell membranes required for syncytium formation by human T-cell lymphotropic virus type 1-bearing cells

“…Mature gp46 and gp21 proteins (a generous gift from H. Miyakoshi, Diagnostics Research Laboratory, Fujirebio, Tokyo) were purified from culture fluids of HTLV-1-producing TCL-Kan cells. Purification of gp46 was achieved by immunoaffinity chromatography and gel chromatography of culture fluids of TCL-Kan cells (26). The supernatant of a culture fluid was concentrated with an Ultrapore membrane filter and disrupted with 1% Nonidet P-40.…”

Western blot seroindeterminate individuals for Human T-lymphotropic Virus 1/2 (HTLV-1/2) in Fortaleza (Brazil): a serological and molecular diagnostic and epidemiological approach

“…Other presumptive associations of indeterminate profiles have been reported with Plasmodium falciparum [22][23][24][25][26][27], varicella zoster virus or herpes simplex [28][29][30][31], and dengue virus [32]. Moreover, recent seroconversion to positivity for HTLV-1/2 [17], incomplete reactions to molecularly distinct variants of HTLV-1/2 or eventually to another exogenous or endogenous retrovirus [30], and transient infection by HTLV-1 [14], have also been reported. Other conditions are also supposedly correlated with a seroindeterminate profile.…”