scholarly journals Detection of anti-HTLV-I Tax antibodies in HTLV-I enzyme-linked immunosorbent assay-negative individuals

Blood ◽  
1989 ◽  
Vol 74 (3) ◽  
pp. 1066-1072
Author(s):  
GD Ehrlich ◽  
JB Glaser ◽  
MA Abbott ◽  
DJ Slamon ◽  
D Keith ◽  
...  

The HTLV-I tax gene protein (Tax) is not packaged within the mature viral particle from which the proteins for the commercially available enzyme-linked immunosorbent assay (ELISA) are derived. Screening of 162 individuals within a cohort of white intravenous (IV) drug abusers, previously identified as having an increased incidence of HTLV-I infection, demonstrated that seven of them had antibodies to the HTLV-I Tax protein but tested negative in HTLV-I ELISAs and Western blots prepared from purified virion proteins. Three out of 35 individuals in other behaviorally defined high-risk groups also displayed this limited pattern of reactivity to HTLV-I proteins. The presence of the anti-HTLV- I p40/Tax antibodies was determined by radioimmunoprecipitation assay (RIPA), which also revealed low levels of anti-env reactivity. The specificity of the anti-p40 reactivity was confirmed on specific Tax ELISAs and Western blots prepared from recombinantly produced Tax. In vitro gene amplification by the polymerase chain reaction (PCR) was used to establish the presence of sequences homologous to HTLV-I proviral DNA in four/four of these HTLV-I ELISA negative, Tax ELISA/Tax western blot/RIPA positive individuals. These data suggest that the true incidence of HTLV-I infection within high-risk cohorts is greater than previously reported.

Blood ◽  
1989 ◽  
Vol 74 (3) ◽  
pp. 1066-1072 ◽  
Author(s):  
GD Ehrlich ◽  
JB Glaser ◽  
MA Abbott ◽  
DJ Slamon ◽  
D Keith ◽  
...  

Abstract The HTLV-I tax gene protein (Tax) is not packaged within the mature viral particle from which the proteins for the commercially available enzyme-linked immunosorbent assay (ELISA) are derived. Screening of 162 individuals within a cohort of white intravenous (IV) drug abusers, previously identified as having an increased incidence of HTLV-I infection, demonstrated that seven of them had antibodies to the HTLV-I Tax protein but tested negative in HTLV-I ELISAs and Western blots prepared from purified virion proteins. Three out of 35 individuals in other behaviorally defined high-risk groups also displayed this limited pattern of reactivity to HTLV-I proteins. The presence of the anti-HTLV- I p40/Tax antibodies was determined by radioimmunoprecipitation assay (RIPA), which also revealed low levels of anti-env reactivity. The specificity of the anti-p40 reactivity was confirmed on specific Tax ELISAs and Western blots prepared from recombinantly produced Tax. In vitro gene amplification by the polymerase chain reaction (PCR) was used to establish the presence of sequences homologous to HTLV-I proviral DNA in four/four of these HTLV-I ELISA negative, Tax ELISA/Tax western blot/RIPA positive individuals. These data suggest that the true incidence of HTLV-I infection within high-risk cohorts is greater than previously reported.


2006 ◽  
Vol 13 (3) ◽  
pp. 420-422 ◽  
Author(s):  
S. E. Burastero ◽  
C. Paolucci ◽  
D. Breda ◽  
G. Monasterolo ◽  
R. E. Rossi ◽  
...  

ABSTRACT The Bühlmann CAST 2000 enzyme-linked immunosorbent assay is a potentially useful assay for measuring sulfidoleukotrienes released in vitro by allergen-challenged basophils. However, we observed that the positive-control reagent yielded positive signals in cell-free systems. These false-positive results depended on using a mouse anti-FcεRI monoclonal antibody and were prevented by degranulation-inducing reagents other than mouse monoclonal antibodies.


2011 ◽  
Vol 18 (5) ◽  
pp. 578-586 ◽  
Author(s):  
Woojun Kim ◽  
Ji-Eun Lee ◽  
Xue Feng Li ◽  
Su-Hyun Kim ◽  
Byeong-Gu Han ◽  
...  

Background: Antibodies to aquaporin-4 (AQP4-Ab), known as NMO-IgG, are a sensitive and specific marker for neuromyelitis optica (NMO). Methods: To develop an enzyme-linked immunosorbent assay (ELISA) for AQP4-Ab, we expressed M23 isoform of human AQP4 in a baculovirus system, and used it as an antigen. We measured AQP4-Ab in the sera of 300 individuals: 64 with definite NMO, 31 with high-risk NMO, 105 with multiple sclerosis (MS), 57 with other neurological diseases (ONDs), and 43 healthy controls. We also performed longitudinal measurements of AQP4–Ab in 787 samples collected from 51 patients with definite or high-risk NMO. Results: AQP4-Abs were positive in 72% with definite NMO, 55% with high-risk NMO, and 4% with MS, but none of the OND patients and the healthy individuals. The longitudinal measurement showed AQP4-Ab levels correlating with disease activity. Out of 38 initially seropositive patients, 21 became seronegative under effective immunosuppressive therapy. During most relapses, the serum AQP4-Ab levels were either high or rising compared with the previous value, although rising AQP4-Ab levels did not always lead to acute exacerbation. Two of the 13 initially seronegative patients converted to seropositive following acute exacerbations. Conclusions: We established an AQP4-Ab ELISA, which could be a potential monitoring tool of disease activity.


2012 ◽  
Vol 25 (5) ◽  
pp. 607-619 ◽  
Author(s):  
Thacianna Barreto da Costa ◽  
Natália Gomes de Morais ◽  
Thays Miranda de Almeida ◽  
Maiara Santos Severo ◽  
Célia Maria Machado Barbosa de Castro

OBJETIVO: Avaliar a influência da desnutrição neonatal sobre a produção de Interferon gama, Interleucina-12 e Interleucina-10 em cultura de macrófagos alveolares e linfócitos infectados, in vitro, com Staphylococcus aureus sensível/resistente à meticilina. MÉTODOS: Ratos machos Wistar foram amamentados por mães cuja dieta, durante a lactação, continha 17% de proteína no grupo nutrido e 8% no grupo desnutrido. Após desmame, ambos os grupos receberam a dieta normoproteica. Os macrófagos foram obtidos após traqueostomia, através da coleta do lavado broncoalveolar. Para obtenção dos linfócitos, foi realizado o procedimento cirúrgico de punção cardíaca. Após o isolamento dos diferentes tipos celulares, procedeuse à realização dos estímulos com as cepas de estudo. A dosagem das citocinas foi realizada pelo método de Enzyme-Linked Immunosorbent Assay, a partir de amostras coletadas do sobrenadante das culturas após 24 horas de incubação. RESULTADOS: A desnutrição acarretou diminuição do crescimento ponderal, redução na produção de Interferon gama em cultura de macrófagos alveolares e linfócitos e diminuição na produção de Interleucina-12 em cultura de macrófagos alveolares. Apenas a produção de Interferon gama e Interleucina-10 em cultura de macrófagos alveolares apresentou diferença entre as cepas analisadas, em ambos os grupos estudados. CONCLUSÃO: O modelo de desnutrição neonatal produziu sequela no peso corporal e reduziu a produção de citocinas próinflamatórias (Interleucina-12 e Interferon gama), indicando que esse modelo de desnutrição pode comprometer a resolução de um processo infeccioso. A cepa de Staphylococcus aureus resistente à meticilina estimulou uma maior produção de Interferon gama e Interleucina-10 por macrófagos alveolares, o que sugeriu estimulação imunológica mais intensa, por essa cepa, nesse tipo celular especificamente.


2000 ◽  
Vol 38 (7) ◽  
pp. 2611-2621 ◽  
Author(s):  
Joppe W. R. Hovius ◽  
K. Emil Hovius ◽  
Anneke Oei ◽  
Dirk J. Houwers ◽  
Alje P. van Dam

In an area where Lyme disease is endemic in The Netherlands all dogs had positive titers by whole-cell enzyme-linked immunosorbent assay and appeared to be naturally infected by Borrelia burgdorferi sensu lato. To compare the antibody responses of symptomatic dogs and asymptomatic controls, we performed Western blots and in vitro immobilization assays to study antibody-dependent bactericidal activity. Strains from three different genospecies were employed as the antigen source: B. burgdorferi strain B31,Borrelia garinii strain A87S, and Borrelia afzelii strain pKo. Antibodies against flagellin (p41) and p39 for three strains were found in sera from both symptomatic and asymptomatic dogs and were therefore considered to be markers of exposure. Antibodies against p56 and p30 of strain B31, against p75, p58, p50, OspC, and p<19 of strain A87S, and against p56, p54, p45, OspB, p31, p26, and p<19 of strain pKo were found significantly more frequently in sera from symptomatic dogs younger than 8 years when the first symptoms were observed than in those from age-matched controls (P < 0.01). These antibodies were not found in preclinical sera and appeared during development of disease. Antibodies against OspA of strains B31 and A87S were only seen in acute-phase and convalescent sera from three dogs that recovered from disease. Incubation with 25% normal canine serum did not result in the immobilization of strains B31 and pKo, but partial immobilization of strain A87S (61% ± 24% [standard deviation] at 5 h) occurred. Seven of 15 sera from symptomatic dogs but none of the sera from 11 asymptomatic dogs had antibody-dependent immobilizing activity against one of the strains. Consecutive sera from one of these dogs immobilized two different strains. Antibody-mediated bactericidal serum was not seen before onset of disease, was strongest in the acute phase of disease, and fluctuated during chronic disease. From seven out of eight symptomatic dogs Borrelia DNA was amplified by PCR; in three of them the bactericidal activity was directed against one of the genospecies amplified from that dog; however, four PCR-positive dogs lacked bactericidal activity. In conclusion, dogs with symptomatic canine borreliosis have more-extensive antibody reactivity against Borrelia, as shown by both Western blotting and immobilization assays.


1986 ◽  
Vol 13 (2) ◽  
pp. 64-67 ◽  
Author(s):  
J. L. Sherwood ◽  
H. A. Melouk

Abstract Western blotting was used to detect infections of peanut cv. Tamnut 74 with peanut mottle virus (PMV) and/or peanut stripe virus (PStV). Leaf samples were ground in electrophoresis sample buffer and heated for 5 min at 95 C prior to electrophoresis in 12% polyacrylamide gels. After electrophoresis, proteins were transferred to nitrocellulose sheets at 100V for 45 min. Western blots were performed by first blocking unbound sites on the nitrocellulose with 5% non-fat dry milk in Tris-buffered saline (TBS), pH 7.4 for 30 min, followed by incubation in a 1/200 dilution of PMV and/or PStV antiserum in TBS (the latter antiserum provided by J. W. Demski, U. of GA) for 45 min. This was followed by incubation in protein-A-peroxidase (2 μg/mL in TBS) for 45 min, followed by 4-chloro-1-napthol plus hydrogen peroxide in TBS. As little as 25 ng of either purified PMV or PStV was detected. This was similar to the limits of detection fo the double sandwich enzyme linked immunosorbent assay (ELISA). Because of the difference in migration of the coat proteins of PMV and PStV, both viruses may be detected in plants infected with PMV and PStV. This assay can be performed in approximately 6 h when mini-gels are used for the initial electrophoretic seperation and does not require the antiserum to be fractionated or bound to an enzyme as is the case with ELISA.


2001 ◽  
Vol 8 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Fuat Özyörük ◽  
William P. Cheevers ◽  
Gordon A. Hullinger ◽  
Travis C. McGuire ◽  
Melinda Hutton ◽  
...  

ABSTRACT Four immunoglobulin G1 monoclonal antibodies (MAbs) to the gp135 surface envelope glycoprotein (SU) of the 79–63 isolate of caprine arthritis-encephalitis virus (CAEV), referred to as CAEV-63, were characterized and evaluated for their ability to compete with antibody from CAEV-infected goats. Three murine MAbs (MAbs GPB16A, 29A, and 74A) and one caprine MAb (MAb F7-299) were examined. All MAbs reacted in nitrocellulose dot blots with native CAEV-63 SU purified by MAb F7-299 affinity chromatography, whereas none reacted with denatured and reduced SU. All MAbs reacted in Western blots with purified CAEV-63 SU or the SU component of whole-virus lysate following denaturation in the absence of reducing agent, indicating that intramolecular disulfide bonding was essential for epitope integrity. Peptide-N-glycosidase F digestion of SU abolished the reactivities of MAbs 74A and F7-299, whereas treatment of SU withN-acetylneuraminate glycohydrolase (sialidase A) under nonreducing conditions enhanced the reactivities of all MAbs as well as polyclonal goat sera. MAbs 29A and F7-299 were cross-reactive with the SU of an independent strain of CAEV (CAEV-Co). By enzyme-linked immunosorbent assay (ELISA), the reactivities of horseradish peroxidase (HRP)-conjugated MAbs 16A and 29A with homologous CAEV-63 SU were <10% of that of HRP-conjugated MAb 74A. The reactivity of HRP-conjugated MAb 74A was blocked by sera from goats immunized with CAEV-63 SU or infected with CAEV-63. The reactivity of MAb 74A was also blocked by sera from goats infected with a CAEV-Co molecular clone, although MAb 74A did not react with CAEV-Co SU in Western blots. Thus, goats infected with either CAEV-63 or CAEV-Co make antibodies that inhibit binding of MAb 74A to CAEV-63 SU. A competitive-inhibition ELISA based on displacement of MAb 74A reactivity has potential applicability for the serologic diagnosis of CAEV infection.


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