Human T cell lymphotropic virus type II infection in Argentina.
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Argentina↗
Biomedical subjects
D Gallo
Publications and source records attributed to D Gallo.
Detection and differentiation of antibodies to human T-cell lymphotropic virus types I and II by the immunofluorescence method.
We compared the sensitivities of the prototype human T-cell lymphotropic virus type I (HTLV-I)- and HTLV-II-transformed cell lines, MT2 and Mo-T, with that of an HTLV-II-infected cell line, clone 19, established in our laboratory, in the immunofluorescence (IF) test for detection of antibody to HTLV-I and HTLV-II. In addition, IF antibody titers with the three antigens were determined, and the results were compared with HTLV-I and HTLV-II typing by polymerase chain reaction (PCR). The MT2 cell line was more sensitive than the two HTLV-II cell lines for detecting HTLV-I antibody by IF, and clone 19 was more sensitive than Mo-T or MT2 for measuring HTLV-II antibody. In the titration study, the antigen that gave the highest titer correlated completely with the HTLV type determined by PCR, indicating that the relatively simple IF titration method can be used for differentiating HTLV-I and HTLV-II antibody in sera and plasmas.
Cell Line, Transformed↗
High prevalence of HTLV-II among intravenous drug abusers: PCR confirmation and typing.
The polymerase chain reaction (PCR) was used to confirm the presence of human T-cell lymphotropic viruses (HTLV) in intravenous drug users (IVDU) whose sera were reactive by immunofluorescence assay (IFA) for HTLV-1/-II antibody. Peripheral blood mononuclear cells from 41 IFA-positive and 19 IFA-negative individuals were analyzed. HTLV sequences were detected in 39/41 IFA-positive samples; 36 were HTLV-II positive and 3 were HTLV-I positive. Two IFA antibody-positives were negative by both PCR and by enzyme immunoassay (EIA). One IFA and EIA antibody-negative sample was positive for HTLV-II by PCR. This study indicates a high prevalence of HTLV-II among IVDUs and further demonstrates the feasibility of using PCR to differentiate between HTLV-I and -II.
Fluorescent Antibody Technique↗
Comparison of Western immunoblot antigens and interpretive criteria for detection of antibody to human T-lymphotropic virus types I and II.
Twenty human T-lymphotropic virus type I (HTLV-I) antibody-positive sera from Japan, Hawaii, and the Marshall Islands and 15 HTLV type II (HTLV-II) antibody-positive sera from intravenous drug users in the United States were tested by immunoblotting with two recombinant HTLV-I proteins and three commercial kits to determine whether there were any differences in reactions between HTLV-I- and HTLV-II-positive sera by the Western immunoblot method and, also, to evaluate the ability of these reagents to detect HTLV-I- and HTLV-II-seropositive individuals by using the recommended Western blot interpretation. These sera were first extensively characterized by immunofluorescence, enzyme immunoassay, radioimmunoprecipitation assay, and Western blot using HTLV-I and HTLV-II viral lysates and an envelope (env) recombinant protein. Although both HTLV-I- and HTLV-II antibody-positive sera reacted with the env protein gp68, reactions with the gp46 env antigens appeared to be specific for HTLV-I. It was found that the use of either p19 or p24 core bands plus an env reaction instead of only the p24 plus env reaction (as presently recommended) increased the number of positive interpretations for HTLV-I but had no effect on the number of HTLV-II-positive interpretations.
Blotting, Western↗
Isolation of human immunodeficiency virus from peripheral blood lymphocytes stored in various transport media and frozen at -60 degrees C.
The peripheral blood lymphocytes from 48 heparinized blood specimens from human immunodeficiency virus (HIV) antibody-positive individuals were divided into two aliquots. One aliquot was reconstituted in one of the following five media. Medium 1 consisted of tryptose broth with 0.5% gelatin; medium 2 consisted of RPMI 1640 containing 10% fetal bovine serum (FBS); medium 3 consisted of RPMI 1640 containing 20% FBS, Polybrene, interleukin 2, and anti-alpha interferon; medium 4 consisted of medium 2 plus 10% dimethyl sulfoxide (DMSO); and medium 5 consisted of medium 3 plus 10% DMSO. Lymphocytes were stored in these five media at -60 degrees C. The other aliquot of cells was stored at -190 degrees C in RPMI 1640 containing 50% FBS and 10% DMSO. After 1 week, both aliquots were cocultivated with phytohemagglutinin-stimulated uninfected peripheral blood lymphocytes, and presence of HIV was detected by the reverse transcriptase test. Storage in medium 1, 2, or 3 did not result in satisfactory isolation rates, but storage at -60 degrees C in medium 4 or 5 gave equal or better isolation rates than did storage at -190 degrees C. Inactivation of HIV by freezing of the cells without DMSO correlated with high antibody titers to core and polymerase proteins as measured by Western (immuno-) blotting.
Acquired Immunodeficiency Syndrome↗
Application of HIV methods to the detection of other retroviruses.
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AIDS Serodiagnosis↗
Comparison of immunofluorescence, enzyme immunoassay, and Western blot (immunoblot) methods for detection of antibody to human T-cell leukemia virus type I.
A total of 3,349 serum samples were screened by the immunofluorescence (IF) method for antibody to human T-cell leukemia virus type I (HTLV-I). Only 9 of 2,409 specimens from selected individuals, blood bank donors, patients with encephalitis-meningitis, and human immunodeficiency virus antibody-positive homosexual or bisexual men were reactive by IF. In addition, 940 serum samples from intravenous drug abusers were tested by IF and also by an HTLV-I enzyme immunoassay (EIA) method. Of these, 222 (24%) were positive for both HTLV-I and HTLV-II antigens by IF, and 191 of these 222 were also reactive in the HTLV-I EIA. Of the 31 IF-positive, EIA-negative serum samples, 20 exhibited optical density readings greater than or equal to 70% of the positive cutoff in the EIA, and 29 samples reacted with 1 or more bands in the Western blot (immunoblot) test. An additional 10 specimens that were EIA negative reacted only with HTLV-I by IF. Differences in staining morphology and in reactions on HTLV-I and HTLV-II antigens before and after absorption of the serum specimens with HTLV-I and HTLV-II-infected cell pellets revealed six distinct serological patterns by IF. These results indicate that infections by HTLV-I or by another closely related retrovirus(es) occur in California. Further studies utilizing statistically valid sampling methods are needed to estimate true prevalence rates among various groups. IF and Western blot tests should supplement the EIA method to maximize sensitivity and specificity of test procedures.
Blotting, Western↗
Comparative studies on use of fresh and frozen peripheral blood lymphocyte specimens for isolation of human immunodeficiency virus and effects of cell lysis on isolation efficiency.
Heparinized blood specimens (n = 44) and frozen peripheral blood lymphocyte (PBL) specimens (n = 42) were used to evaluate the effects of lysis on human immunodeficiency virus (HIV) isolation. In the two respective groups, 17 and 27 specimens were HIV antibody positive. In the first group there were 8 and in the second group there were 25 that were symptomatic and were classified as indicating an acquired immunodeficiency syndrome-related condition or a pre-acquired immunodeficiency syndrome-related condition by the Centers for Disease Control definition. One-half of the cells from each specimen were frozen and thawed three times before cocultivation with uninfected lymphocytes, and the isolation rates from whole and lysed cells were compared. HIV was isolated from 15 (88%) of 17 fresh specimens and from 24 (89%) of 27 frozen PBLs from HIV antibody-positive patients, and lysis had no overall effect on the isolation rate, which suggested that frozen PBLs were as suitable as fresh blood for HIV isolation attempts and that it was not necessary to maintain cell integrity when submitting PBL samples. Of 21 asymptomatic patients, 20 were culture positive, and of 23 symptomatic patients, 19 were culture positive. Specimens from the 42 antibody-negative individuals were culture negative.
Freezing↗
Comparison of detection of antibody to the acquired immune deficiency syndrome virus by enzyme immunoassay, immunofluorescence, and Western blot methods.
There was 100% agreement between enzyme immunoassay (EIA) (Abbott Laboratories), Western blot, and indirect immunofluorescence (IF) when these three methods were used to measure antibody to the acquired immune deficiency syndrome (AIDS) virus in sera from 142 high-risk individuals, indicating that IF was a sensitive alternative method for detecting antibody to this agent. Thirty-two (64%) of 50 EIA-positive plasma specimens from a blood bank and 6 (21%) of 28 EIA-positive sera from alternative testing sites were negative by IF. In addition, two EIA-negative sera from the latter group were positive by IF. Western blotting agreed with IF on those 40 specimens which gave discrepant results by EIA and IF. The IF method was determined to be equal to Western blotting in sensitivity and specificity for detection of AIDS antibody, and it was found to be useful for confirming positive EIA results, especially in specimens from individuals in low-risk groups.
Acquired Immunodeficiency Syndrome↗
Elimination of Fc receptor binding of human immunoglobulin G in immunofluorescence assays for herpes simplex virus antibodies.
The binding of human immunoglobulin G by Fc receptors in herpes simplex virus (HSV)-infected cells can cause false-positive interpretations in the immunofluorescence test for HSV antibody. When the infected cell smears were treated with 10% glacial acetic acid for 5 min and rinsed in phosphate-buffered saline before the immunofluorescence test was performed, the Fc receptors were completely inactivated, resulting in a reliable method for HSV antibody detection.
Acetates↗
Enzyme immunoassay versus plaque neutralization and other methods for determination of immune status to measles and varicella-zoster viruses and versus complement fixation for serodiagnosis of infections with those viruses.
Results by an enzyme immunoassay method (EIA) performed at one serum dilution and results by indirect immunofluorescence (IFA) and hemagglutination inhibition (HI) tests performed at step dilutions were correlated with results by a neutralization test (50% plaque neutralization [PN]) performed at step dilutions on single serum samples for serologic evaluation of immunity status to measles virus. PN results were taken as true indicators of immunity, and the other tests were evaluated on that basis. The predictive value of a positive result being positive also by PN was 95.3% for HI and 93.3% for EIA and IFA. The predictive value of a negative result being negative also by PN was 81.1% for HI, 100% for EIA, and 75.0% for IFA. A similar study on immunity status to varicella-zoster virus by EIA and by an anticomplement immunofluorescence test versus PN showed a 100% predictive value of a positive or negative result by EIA. By the anticomplement immunofluorescence test, the predictive value of a positive result was 97.7%, and that of a negative result was 88.5%. Studies on the comparative ability of EIA versus complement fixation (CF) to detect significant changes in antibody concentration between acute-phase and convalescent-phase serum samples indicative of a current infection were also done. Both tests were satisfactory for the serodiagnosis of measles or varicella-zoster virus infections. However, EIA was preferable to CF because it was less technically difficult, less labor intensive, and could be performed on sera that were anticomplementary in CF reactions.
Antigens, Viral↗
[Sisomicin in infections of the newborn].
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Bacterial Infections↗
Class-specific antibody responses to early and late antigens of varicella and herpes simplex viruses.
Antibody responses to early antigens of varicella-zoster virus (VZV), simian varicella virus, and herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) were studied in primary, secondary, and latent infections. IgG antibody responses to the early antigens occurred in primary and secondary VZV and HSV infections, and antibodies to early antigens were also demonstrable in healthy individuals with latent VZV and HSV infections, indicating that the presence of antibodies to early antigens cannot be taken as evidence of active infection with the viruses. Patients with current VZV or HSV infections showed heterotypic IgG antibody responses to early antigens of VZV and HSV to the same extent as to late antigens. In all groups of patients, IgG antibody titers to early antigens were similar to those against the corresponding late antigens, and no difference was seen in the reactivity of early antigens produced with four different blocking agents (cytosine arabinoside, bromodeoxyuridine, trisodium phosphonoformate, and cycloheximide). Antibodies of the IgM and IgA classes reacted with both early and late antigens of HSV, but only with late antigens of VZV and simian varicella virus, suggesting that these antibodies may be directed against late proteins that are expressed to a greater extent in HSV-infected cells treated with blocking agents than they are expressed in treated VZV-infected cells. Homologous IgM antibody responses occurred in both primary and secondary VZV infections, but only in primary HSV infections. Heterotypic IgM responses to HSV-2 antigen were noted in a few VZV patients who did not have demonstrable IgG antibody to HSV, suggesting that even in patients without prior experience with HSV, a VZV infection may stimulate the production of IgM antibodies that react with antigens that are shared by VZV and HSV-2. IgA antibodies to late antigens of VZV and HSV were demonstrable in latent, as well as active, infections with these viruses.
Animals↗
Broadly reactive immunofluorescence test for measurement of immunoglobulin M and G antibodies to Ureaplasma urealyticum in infant and adult sera.
The indirect immunofluorescence test was used to measure immunoglobulin M (IgM) and IgG antibodies to acetone-fixed Ureaplasma urealyticum organisms in sera from 128 adults with genital infections and from 713 symptomatic newborns and babies 1 day to 18 months old. Thirty-four percent of the adults had demonstrable IgG antibody to ureaplasma. IgM antibody was detected in 2 of the adult sera and in 17 of the infant sera. These babies were divided into two distinct groups. Ten of the infants presented at birth with various physical findings, whereas the onset of symptoms for the other 7 occurred 3 to 13 weeks after birth, and the major clinical finding in 6 of the 7 was respiratory distress. The results of this study suggested that U. urealyticum infection may be associated with fetal damage and infant pneumonia, and if this is substantiated, the indirect immunofluorescence test employing acetone-fixed antigen to measure IgM antibody to U. urealyticum may be an important diagnostic tool.
Adult↗
Comparison of direct immunofluorescence and direct immunoperoxidase procedures for detection of herpes simplex virus antigen in lesion specimens.
Direct immunofluorescence and direct immunoperoxidase staining were equally sensitive and specific for detection of herpes simplex virus antigen in lesion specimens, and each method showed 82% agreement with virus isolation results.
Antigens, Viral↗
Uses of immunofluorescence in diagnostic virology.
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Antibodies, Viral↗
Serological reactivity of some monoclonal antibodies to varicella-zoster virus.
Monoclonal antibodies to varicella-zoster virus, free from host cell reactivity, were produced by cell fusion technics. Antibodies from four different clones showed diverse activities in neutralization immunofluorescence and complement fixation assays. The antibodies provide useful reagents for viral diagnosis and viral antigenic characterization.
Animals↗