scholarly journals Are HIV-1-Specific Antibody Levels Potentially Useful Laboratory Markers to Estimate HIV Reservoir Size? A Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Silvere D. Zaongo ◽  
Feng Sun ◽  
Yaokai Chen

Despite the benefits achieved by the widespread availability of modern antiretroviral therapy (ART), HIV RNA integration into the host cell genome is responsible for the creation of latent HIV reservoirs, and represents a significant impediment to completely eliminating HIV infection in a patient via modern ART alone. Several methods to measure HIV reservoir size exist; however, simpler, cheaper, and faster tools are required in the quest for total HIV cure. Over the past few years, measurement of HIV-specific antibodies has evolved into a promising option for measuring HIV reservoir size, as they can be measured via simple, well-known techniques such as the western blot and enzyme-linked immunosorbent assay (ELISA). In this article, we re-visit the dynamic evolution of HIV-1-specific antibodies and the factors that may influence their levels in the circulation of HIV-positive individuals. Then, we describe the currently-known relationship between HIV-1-specific antibodies and HIV reservoir size based on study of data from contemporary literature published during the past 5 years. We conclude by highlighting current trends, and discussing the individual HIV-specific antibody that is likely to be the most reliable antibody for potential future utilization for quantification of HIV reservoir size.

Author(s):  
ZM Huo ◽  
J Miles ◽  
PG Riches ◽  
T Harris

Background: Measurement of antibody responses to polysaccharide antigens is regarded as an important assessment of an individual's ability to respond to carbohydrate antigens. The currently used assays for the measurement of pneumococcal-specific antibody use the multi-serotype vaccine Pneumovax® as the detection antigen. Methods: An equal potency enzyme-linked immunosorbent assay (ELISA) system was used to compare the measurement of serotype-specific antibody with the multi-serotype assay. Results: Our results show that the concentration of specific antibody to Pneumovax is not related to the concentration of antibody to the individual serotypes. Neither is any correlation found between the antibody concentrations to any of the three single serotypes investigated, to the mixture of the three serotypes or to Pneumovax. Conclusion: We conclude that the measurement of the concentration of the specific antibody to the mixed serotypes present in Pneumovax has serious limitations when used to evaluate the protection acquired from Pneumovax immunization against any specific serotype.


2002 ◽  
Vol 70 (4) ◽  
pp. 2171-2177 ◽  
Author(s):  
Mary C. Hu ◽  
Michael A. Walls ◽  
Steven D. Stroop ◽  
Mark A. Reddish ◽  
Bernard Beall ◽  
...  

ABSTRACT A multivalent vaccine containing amino-terminal M protein fragments from 26 different serotypes of group A streptococci was constructed by recombinant techniques. The vaccine consisted of four different recombinant proteins that were formulated with alum to contain 400 μg of protein per dose. Rabbits were immunized via the intramuscular route at 0, 4, and 16 weeks. Immune sera were assayed for the presence of type-specific antibodies against the individual recombinant M peptides by enzyme-linked immunosorbent assay and for opsonic antibodies by in vitro opsonization tests and indirect bactericidal tests. The 26-valent vaccine was highly immunogenic and elicited fourfold or greater increases in antibody levels against 25 of the 26 serotypes represented in the vaccine. The immune sera were broadly opsonic and were bactericidal against the majority of the 26 different serotypes. Importantly, none of the immune sera cross-reacted with human tissues. Our results indicate that type-specific, protective M protein epitopes can be incorporated into complex, multivalent vaccines designed to elicit broadly protective opsonic antibodies in the absence of tissue-cross-reactive antibodies.


2007 ◽  
Vol 15 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Olga Sánchez Negrette ◽  
Fernando J. Sánchez Valdéz ◽  
Carlos D. Lacunza ◽  
María Fernanda García Bustos ◽  
María Celia Mora ◽  
...  

ABSTRACT Serological tests are the main laboratory procedures used for diagnosis during the indeterminate and chronic stages of Chagas' disease. A serological regression to negativity is the main criterion used to define parasitological cure in treated patients. The aim of this work was to monitor the individual specificities of antibody levels for 3 years posttreatment in 18 adult patients. Conventional serological techniques (hemagglutination assays and enzyme-linked immunosorbent assay [ELISA]) were modified by using recombinant antigens to detect early markers of treatment effectiveness. For this purpose, serum samples were taken before and during treatment and every 6 months after treatment for at least 3 years. When hemagglutination assays were used, a decrease in antibody levels was observed in only one patient. When ELISA with serum dilutions was used, antibody clearance became much more apparent: in 77.7% (14/18) of the patients, antibody titers became negative with time. This was observed at serum dilutions of 1/320 and occurred between the 6th and the 30th months posttreatment. The immune response and the interval for a serological regression to negativity were different for each patient. For some of the recombinant antigens, only 50% (9/18) of the patients reached the serological regression to negativity. Recombinant antigen 13 might be a good marker of treatment effectiveness, since 66.6% (six of nine) of the patients presented with an early regression to negativity for specific antibodies to this antigen (P = 0.002).


1998 ◽  
Vol 5 (5) ◽  
pp. 613-616 ◽  
Author(s):  
Felix Grimm ◽  
Friedrich E. Maly ◽  
Jian Lü ◽  
Roberto Llano

ABSTRACT The potential roles of specific antibodies of the different immunoglobulin G (IgG) subclasses in the serological diagnosis of cystic echinococcosis (CE) and alveolar echinococcosis (AE) were investigated by an enzyme-linked immunosorbent assay based on hydatid fluid as antigen. Specific antibodies of subclass 1 were found to be of major importance. In sera collected at the time of diagnosis (i.e., before any therapeutic intervention was initiated) they could be demonstrated in 14 of 15 sera from patients with CE and in all 12 sera from patients with AE. The most discriminatory and the most specific antibodies found in this study belonged to IgG subclass 4. Only one false-positive reaction was observed with 253 sera from healthy volunteers, and no cross-reactions occurred in 80 sera from patients with different parasitic infections. Specific IgG4 antibodies could be demonstrated in 61.0 to 66.7% (CE) or 47.6 to 66.7% (AE) of the cases. Antibody levels of IgG subclass 2 were elevated only moderately, and subclass 3 antibodies were detected in a few cases only. In addition, nonspecific reactions in sera of healthy volunteers or patients with other parasitic infections could partially be attributed to antibodies of subclasses 2 and 3.


1984 ◽  
Vol 47 (7) ◽  
pp. 562-569 ◽  
Author(s):  
FUN SUN CHU

During the past few years, several laboratories have prepared specific antibodies against aflatoxins B1, M1, B2a and Q1, ochratoxin A, T-2 toxin, and zearalenone. These antibodies were obtained from rabbits after immunizing with various mycotoxin-protein conjugates. With the availability of these antibodies, specific, simple and sensitive radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) procedures for monitoring mycotoxins and their metabolites in foods, feeds and body fluids have been developed. In this review, details are presented for the preparation of antibodies and the application of RIA and ELISA to determine aflatoxins B1 and M1, ochratoxin A and T-2 toxin in corn, peanuts, milk and other biological fluids. The sensitivity of ELISA for analysis of these mycotoxins in foods varied from 0.1 μg/L for aflatoxin M1 in milk to 5 μg/kg of aflatoxin B1 in peanuts. The advantages and disadvantages of ELISA for monitoring mycotoxins in foods and feeds are discussed. In addition, a description of recent progress on simplified clean-up procedures which may increase the sensitivity of immunoassays is presented.


1990 ◽  
Vol 11 (4) ◽  
pp. 180-184 ◽  
Author(s):  
Djamshid Shirazian ◽  
Barry C. Herzlich ◽  
Foroozan Mokhtarian ◽  
David Grob

AbstractThere is a significant rate of percutaneous injury with needles during the care of patients with acquired immunodeficiency syndrome (AIDS). Following puncture injury, it is recommended that the source of the contaminating blood be checked, and if human immunodeficiency virus-type 1- (HIV-1)-seropositive, zidovudine prophylaxis be considered. As the source of contaminating blood may be unknown, we studied the detectability of HIV-1 antibody and circulating antigen (p24) in the residual blood from needles and pieces of glass at various intervals following exposure to blood. The residual volume of blood remaining in needles varied from 183 ±50 μ 1 for a 20 G needle to 7.8 ± 1 μ 1 for a 27 G needle, and the residual blood on small pieces of glass varied from 23 μ 1 for a piece weighing 558 mg to 2 μ 1 for a piece weighing 21 mg. Analysis of washed samples of residual blood from all 20 G through 26 G needles and from broken pieces of glass larger than 0.41 g that had been exposed to HIV-1-seropositive blood and left at room temperature for one hour, one day and one week resulted in positive tests for HIV-1 antibody by enzyme-linked immunosorbent assay (ELISA), immunofluorescence and Western blot assays. The circulating antigen was detected in residual blood of 20 G through 26 G needles, but not from contaminated pieces of glass. This technique could be applied to situations where a healthcare worker pricked him- or herself with a needle or with a piece of glass that had been contaminated with blood of unknown seroreactivity. If HIV-1 ELISA, immunofluorescence, Western blot and circulating antigen assays are negative, the individual can be reassured. Because only 0.4% of needlestick injuries with HIV-1-seropositive blood have resulted in seroconversion, there must be other factors, as yet unknown, that predispose to infection.


2007 ◽  
Vol 75 (9) ◽  
pp. 4456-4462 ◽  
Author(s):  
Frans N. J. Kooyman ◽  
Erik de Vries ◽  
Harm W. Ploeger ◽  
Jos P. M. van Putten

ABSTRACT Parasite N-glycans may play an important role in helminth infections. As antibodies from Dictyocaulus viviparus-infected calves strongly react with N-glycans, we investigated the characteristics of the major immunodominant glycoprotein (GP300) of this parasite. Probing of worm extracts with various lectins demonstrated unique binding of GP300 to wheat germ agglutinin. Analysis of lectin-purified GP300 revealed that the glycan was substituted with phosphorylcholine and reacted with the phosphorylcholine-specific antibody TEPC-15. Competitive enzyme-linked immunosorbent assay with GP300-coated plates and GP300-specific immunoglobulin G (IgG) in conjunction with free phosphorylcholine or TEPC-15 demonstrated that antibodies from infected calves recognized phosphorylcholine on GP300. Additional assays showed that these antibodies cross-reacted with the phosphorylcholine moiety present on platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a proinflammatory mediator of the host. Heavily infected calves contained high levels of serum GP300-specific IgG1 but low levels of IgA and IgG2 and showed a reduced influx of eosinophils in the lungs, all consistent with a neutralization of PAF activity. In conclusion, we demonstrated that D. viviparus infection elicits GP300-specific antibodies that cross-react with PAF and may neutralize PAF function, thus limiting the development of a protective response as well as parasite-induced host pathology.


2017 ◽  
Vol 34 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Claudio Rodríguez-Camejo ◽  
Arturo Puyol ◽  
Laura Fazio ◽  
Analía Rodríguez ◽  
Emilia Villamil ◽  
...  

Background: When feeding preterm infants, donor milk is preferred if the mother’s own milk is unavailable. Pasteurization may have detrimental effects on bioactivity, but more information is needed about its effects on the immunological compounds. Research aim: This work has two main aims: evaluate the antibody profile of colostrum and study the quantitative variations in the antibodies’ level and specific reactivity after undergoing Holder pasteurization. The authors focused on immunoregulatory components of colostrum (antidietary antibodies and TGF-β2) in the neonatal gut. Methods: This is a descriptive cross-sectional study of a convenience sample of 67 donated colostrum samples at different days after delivery, both raw and pasteurized. Antibody profiles were analyzed at different times during breastfeeding, and total and specific antibodies (IgM, IgA, and IgG subclasses) were compared with tetanus toxoid and ovalbumin using enzyme-linked immunosorbent assay. The processing effect on total and specific antibodies, as well as TGF-β2, was evaluated by paired analyses. Results: No variations in immunological compounds were observed throughout the colostrum stage. The TGF-β2, antibodies’ concentrations, and antibodies’ specific reactivity after pasteurization did not vary significantly as days of lactation varied. Changes in antibody levels were dependent on isotype and IgG subclass, and IgG4 showed remarkable resistance to heating. Moreover, the effect of the pasteurization on specific reactivity was antigen dependent. Conclusion: The supply of relevant immunological components is stable throughout the colostrum stage. The effects of pasteurization on antibodies depend on isotype, subclass, and specificity. This information is relevant to improving the immunological quality of colostrum, especially for preterm newborns.


1998 ◽  
Vol 36 (10) ◽  
pp. 3028-3031 ◽  
Author(s):  
Liang Cao ◽  
Da-Liang Chen ◽  
Cindy Lee ◽  
Che-Man Chan ◽  
King-Man Chan ◽  
...  

The disseminated and progressive fungal disease Penicillium marneffei penicilliosis is one of the most common infectious diseases in AIDS patients in Southeast Asia. To diagnose systemic penicilliosis, we developed an enzyme-linked immunosorbent assay (ELISA)-based antibody test with Mp1p, a purified recombinant antigenic mannoprotein of P. marneffei. Evaluation of the test with guinea pig sera against P. marneffei and other pathogenic fungi indicated that this assay was specific for P. marneffei. Clinical evaluation revealed that high levels of specific antibody were detected in two immunocompetent penicilliosis patients. Furthermore, approximately 80% (14 of 17) of the documented penicilliosis patients with human immunodeficiency virus tested positive for the specific antibody. No false-positive results were found for serum samples from 90 healthy blood donors, 20 patients with typhoid fever, and 55 patients with tuberculosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Mp1p antibody can be of significant value as a diagnostic for penicilliosis.


1998 ◽  
Vol 64 (12) ◽  
pp. 5033-5038 ◽  
Author(s):  
N. de Vries ◽  
K. A. Zwaagstra ◽  
J. H. J. Huis in’t Veld ◽  
F. van Knapen ◽  
F. G. van Zijderveld ◽  
...  

ABSTRACT Salmonella typhimurium expresses two antigenically distinct flagellins, each containing a different H antigen (i and 1,2), the combination of which is highly specific for this serotype. In this study, overlapping recombinant flagellin fragments were constructed from the fliC(H:i) and fljB (H:1,2) flagellin genes, and the expression products were tested for binding to H antigen-specific monoclonal and polyclonal antibodies. A minimal area, 86 amino acids for H:i and 102 amino acids for H:1,2, located in the central variable domain of each flagellin was required for the binding of serotype-specific antibodies, providing further evidence for the presence of a discontinuous H epitope. Two peptides comprising these areas were shown to be highly suitable for application as antigens in an enzyme-linked immunosorbent assay detecting S. typhimurium-specific antibody.


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