TY - JOUR
T1 - A Monocyte-Derived Factor Interferes with Detection of Reverse Transcriptase in HIV-1 Infection
AU - Recker, David P.
AU - Kindt, Thomas J.
AU - Kulaga, Henrietta
AU - Dorsett, Diane
AU - Folks, Thomas
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1991/1
Y1 - 1991/1
N2 - Culture supernatants from the rabbit macrophage cell line 6083 infected with a retrovirus, human immunodeficiency virus type 1 (HIV-1), were negative for reverse transcriptase (RT) expression although the line was shown to be productively infected by all other criteria tested. Supernatants from uninfected cultures of 6083, the human monocyte line U937, and from freshly isolated peripheral human monocytes, were found to contain a monocyte-derived inhibitory factor (MDIF) which interferes with a standard assay for RT. MDIF is a heat-labile activity of approximately of 40 kD. Both substrates and products of the reverse transcriptase assay are degraded by MDIF which is not affected by reduction and alkylation of disulfide bonds. MDIF is inhibited by the addition of a particular thioated oligonucleotide (S-dG30) to the reaction mixture but this addition also inhibits RT. The optimum method to minimize MDIF interference in the RT assay is by addition of ethylene glycol bis-(β-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA); MDIF requires divalent cations for activity and has a strong preference for calcium which is preferentially chelated by EGTA. The potential presence of this inhibitory activity should be considered when using RT levels as a measure of retroviral infection.
AB - Culture supernatants from the rabbit macrophage cell line 6083 infected with a retrovirus, human immunodeficiency virus type 1 (HIV-1), were negative for reverse transcriptase (RT) expression although the line was shown to be productively infected by all other criteria tested. Supernatants from uninfected cultures of 6083, the human monocyte line U937, and from freshly isolated peripheral human monocytes, were found to contain a monocyte-derived inhibitory factor (MDIF) which interferes with a standard assay for RT. MDIF is a heat-labile activity of approximately of 40 kD. Both substrates and products of the reverse transcriptase assay are degraded by MDIF which is not affected by reduction and alkylation of disulfide bonds. MDIF is inhibited by the addition of a particular thioated oligonucleotide (S-dG30) to the reaction mixture but this addition also inhibits RT. The optimum method to minimize MDIF interference in the RT assay is by addition of ethylene glycol bis-(β-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA); MDIF requires divalent cations for activity and has a strong preference for calcium which is preferentially chelated by EGTA. The potential presence of this inhibitory activity should be considered when using RT levels as a measure of retroviral infection.
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U2 - 10.1089/aid.1991.7.73
DO - 10.1089/aid.1991.7.73
M3 - Article
C2 - 1707643
AN - SCOPUS:0025971366
VL - 7
SP - 73
EP - 81
JO - AIDS Research and Human Retroviruses
JF - AIDS Research and Human Retroviruses
SN - 0889-2229
IS - 1
ER -