Inhibition of 19-kDa C-terminal region of merozoite surface protein-1-specific antibody responses in neonatal pups by maternally derived 19-kDa C-terminal region of merozoite surface protein-1-specific antibodies but not whole parasite-specific antibodies

Immunizing pregnant women with a malaria vaccine is one approach to protecting the mother and her offspring from malaria infection. However, specific maternal Abs generated in response to vaccination and transferred to the fetus may interfere with the infant's ability to respond to the same vaccine. Using a murine model of malaria, we examined the effect of maternal 19-kDa C-terminal region of merozoite surface protein-1 (MSP1(19)) and Plasmodium yoelii Abs on the pups' ability to respond to immunization with MSP1(19). Maternal MSPI,g-specific Abs but not A yoelii-specific Abs inhibited Ab production following MSP1(19) immunization in 2-wk-old pups. This inhibition was correlated with the amount of maternal MSP1(19) Ab present in the pup at the time of immunization and was due to fewer specific B cells. Passively acquired Ab most likely inhibited the development of an Ab response by blocking access to critical B cell epitopes. If a neonate's ability to respond to MSP1(19) vaccination depends on the level of maternal Abs present at the time of vaccination, it may be necessary to delay immunization until Abs specific for the vaccinating Ag have decreased.

Cross-reactivity of GroEL antibodies with human heat shock protein 60 and quantification of pathogens in atherosclerosis

Background/aims: Chronic infections such as those caused by Chlamydia pneumoniae and periodontopathic bacteria such as Porphyromonas gingivalis have been associated with atherosclerosis, possibly due to cross-reactivity of the immune response to bacterial GroEL with human heat shock protein (hHSP) 60. Methods: We examined the cross-reactivity of anti-GroEL and anti-P. gingivalis antibodies with hHSP60 in atherosclerosis patients and quantified a panel of six pathogens in atheromas. Results: After absorption of plasma samples with hHSP60, there were variable reductions in the levels of anti-GroEL and anti-P. gingivalis antibodies, suggesting that these antibodies cross-reacted with hHSP60. All of the artery specimens were positive for P. gingivalis. Fusobacterium nucleatum, Tannerella forsythia, C. pneumoniae, Helicobacter pylori, and Haemophilus influenzae were found in 84%, 48%, 28%, 4%, and 4% of arteries, respectively. The prevalence of the three periodontopathic microorganisms, P. gingivalis, F. nucleatum and T. forsythia, was significantly higher than that of the remaining three microorganisms. Conclusions: These results support the hypothesis that in some patients, cross-reactivity of the immune response to bacterial HSPs including those of periodontal pathogens, with arterial endothelial cells expressing hHSP60 may be a possible mechanism for the association between atherosclerosis and periodontal infection.

Serum antibodies to oral anaerobic bacteria in patients with rheumatoid arthritis

BACKGROUND: This study was conducted to determine the component that causes the disease in rheumatoid arthritis (RA), which shows great resemblance to periodontitis in a pathologic context. MATERIALS AND METHODS: Within this study, the pathogen-specific IgG levels formed against Porphyromonas gingivalis FDC 381, Prevotella melaninogenica ATCC 25845, Actinobacillus actinomycetemcomitans Y4, Bacteroides forsythus ATCC 43047, and Prevotella intermedia 25611 oral bacteria were researched from the blood serum samples of 30 RA patients and 20 healthy controls with the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: The IgG levels of P gingivalis, P intermedia, P melaninogenica, and B forsythus were found to be significantly higher in RA patients when compared with those of the controls. Of the other bacteria antibodies, A actinomycetemcomitans was not found at greater levels in RA serum samples in comparison with the healthy samples. CONCLUSION: The antibodies formed against P gingivalis, P intermedia, P melaninogenica, and B forsythus could be important to the etiopathogenesis of RA.

A systematic review and meta-analysis of the diagnostic accuracy of rapid immunochromatographic assays for the detection of dengue virus IgM antibodies during acute infection

A meta-analysis of rapid (

Epitope-blocking enzyme-linked immunosorbent assay for detection of antibodies to Ross River virus in vertebrate sera

We describe the development of an epitope-blocking enzyme-linked immunosorbent assay (ELISA) for the sensitive and rapid detection of antibodies to Ross River virus (RRV) in human sera and known vertebrate host species. This ELISA provides an alternative method for the serodiagnosis of RRV infections.

Control of culture environment for improved polyethylenimine-mediated transient production of recombinant monoclonal antibodies by CHO cells

In this study we describe optimization of polyethylenimine (PEI)-mediated transient production of recombinant protein by CHO cells by facile manipulation of a chemically defined culture environment to limit accumulation of nonproductive cell biomass, increase the duration of recombinant protein production from transfected plasmid DNA, and increase cell-specific production. The optimal conditions for transient transfection of suspension-adapted CHO cells using branched, 25 kDa PEI as a gene delivery vehicle were experimentally determined by production of secreted alkaline phosphatase reporter in static cultures and recombinant IgG(4) monoclonal antibody (Mab) production in agitated shake flask cultures to be a DNA concentration of 1.25 mu g 10(6) cells(-1) mL(-1) at a PEI nitrogen: DNA phosphate ratio of 20:1. These conditions represented the optimal compromise between PEI cytotoxicity and product yield with most efficient recombinant DNA utilization. Separately, both addition of recombinant insulin-like growth factor (LR3-IGF) and a reduction in culture temperature to 32 degrees C were found to increase product titer 2- and 3-fold, respectively. However, mild hypothermia and LR3-IGF acted synergistically to increase product titer 11-fold. Although increased product titer in the presence of LR3-IGF alone was solely a consequence of increased culture duration, a reduction in culture temperature post-transfection increased both the integral of viable cell concentration (IVC) and cell-specific Mab production rate. For cultures maintained at 32 degrees C in the presence of LR3-IGF, IVC and qMab were increased 4- and 2.5-fold, respectively. To further increase product yield from transfected DNA, the duration of transgene expression in cell populations maintained at 32 C in the presence of LR3-IGF was doubled by periodic resuspension of transfected cells in fresh media, leading to a 3-fold increase in accumulated Mab titer from similar to 13 to similar to 39 mg L-1. Under these conditions, Mab glycosylation at Asn297 remained essentially constant and similar to that of the same Mab produced by stably transfected GS-CHO cells. From these data we suggest that the efficiency of transient production processes (protein output per rDNA input) can be significantly improved using a combination of mild hypothermia and growth factor(s) to yield an extended activated hypothermic synthesis.

Effect of sequence variation in Plasmodium falciparum Histidine-Rich protein 2 on binding of specific monoclonal antibodies: Implications for rapid diagnostic tests for malaria

This Article Right arrow Full Text Right arrow Full Text (PDF) Right arrow Supplemental material Right arrow Alert me when this article is cited Right arrow Alert me if a correction is posted Services Right arrow Similar articles in this journal Right arrow Similar articles in PubMed Right arrow Alert me to new issues of the journal Right arrow Download to citation manager Right arrow Reprints and Permissions Right arrow Copyright Information Right arrow Books from ASM Press Right arrow MicrobeWorld Citing Articles Right arrow Citing Articles via HighWire Right arrow Citing Articles via Google Scholar Google Scholar Right arrow Articles by Lee, N. Right arrow Articles by McCarthy, J. Right arrow Search for Related Content PubMed Right arrow PubMed Citation Right arrow Articles by Lee, N. Right arrow Articles by McCarthy, J. Right arrow Pubmed/NCBI databases * Substance via MeSH Previous Article | Next Article Journal of Clinical Microbiology, August 2006, p. 2773-2778, Vol. 44, No. 8 0095-1137/06/$08.00+0 doi:10.1128/JCM.02557-05 Copyright © 2006, American Society for Microbiology. All Rights Reserved. Effect of Sequence Variation in Plasmodium falciparum Histidine- Rich Protein 2 on Binding of Specific Monoclonal Antibodies: Implications for Rapid Diagnostic Tests for Malaria{dagger} Nelson Lee,1,2 Joanne Baker,2 Kathy T. Andrews,1 Michelle L. Gatton,1,3 David Bell,4 Qin Cheng,2,3 and James McCarthy1* Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research and School of Population Health, University of Queensland, Queensland, Australia,1 Department of Drug Resistance and Diagnostics, Australian Army Malaria Institute, Brisbane, Australia,2 Malaria Drug Resistance and Chemotherapy, Queensland Institute of Medical Research, Queensland, Australia,3 World Health Organization, Regional Office for the Western Pacific, Manila, Philippines4 Received 8 December 2005/ Returned for modification 23 February 2006/ Accepted 26 May 2006 The ability to accurately diagnose malaria infections, particularly in settings where laboratory facilities are not well developed, is of key importance in the control of this disease. Rapid diagnostic tests (RDTs) offer great potential to address this need. Reports of significant variation in the field performance of RDTs based on the detection of Plasmodium falciparum histidine-rich protein 2 (HRP2) (PfHRP2) and of significant sequence polymorphism in PfHRP2 led us to evaluate the binding of four HRP2-specific monoclonal antibodies (MABs) to parasite proteins from geographically distinct P. falciparum isolates, define the epitopes recognized by these MABs, and relate the copy number of the epitopes to MAB reactivity. We observed a significant difference in the reactivity of the same MAB to different isolates and between different MABs tested with single isolates. When the target epitopes of three of the MABs were determined and mapped onto the peptide sequences of the field isolates, significant variability in the frequency of these epitopes was observed. These findings support the role of sequence variation as an explanation for variations in the performance of HRP2-based RDTs and point toward possible approaches to improve their diagnostic sensitivities

Response and function of cutaneous mucosal and serum antibodies in barramundi (Lates calcarifer) acclimated in seawater and freshwater

Mucosal and serum antibody responses were studied in sibling barramundi (Lates calcarifer) acclimated in either seawater or freshwater following vaccination by intraperitoneal injection or direct immersion in an inactivated Streptococcus iniae vaccine. As expected, route of vaccination had a marked effect on immune response, with direct immersion resulting in low serum antibody levels against S. iniae by ELISA detected 21 days post vaccination at 26 degrees C, whilst a significant response was detected in mucus. A strong specific antibody response was detected in both mucus and serum 21 days following intraperitoneal injection. Fish acclimated in seawater prior to vaccination showed a markedly higher specific mucosal antibody response than sibling fish acclimated in freshwater, regardless of the route of vaccination, whilst the serum antibody response was not affected by salinity. Both mucosal and serum antibodies from fish in seawater and freshwater were capable of binding antigen at salinities similar to full strength seawater in a modified ELISA assay. These results indicate that this euryhaline fish species is riot only able to mount significant specific antibody response in cutaneous mucus, but that these antibodies will function in the marine environment. (c) 2005 Elsevier Ltd. All rights reserved.

Alveolar haemorrhage in anti-glomerular basement membrane disease without detectable antibodies by conventional assays

Anti-glomerular basement membrane (anti-GBM) disease represents the spectrum of disease attributable to circulating anti-GBM antibodies. While active anti-GBM disease in the absence of circulating anti-GBM antibodies has been described, it is considered rare with the use of current routinely available assays. We report four subjects with features consistent with active anti-GBM antibody disease without detectable antibodies by routinely available enzyme linked immunosorbent assay (ELISA) and immunoblot techniques. All were smokers who presented with diffuse alveolar haemorrhage, minimal renal involvement, and undetectable anti-GBM antibodies. Seronegative anti-GBM disease with predominant pulmonary involvement may be more common than previously appreciated and should be part of the differential diagnosis for otherwise unexplained diffuse alveolar haemorrhage. Renal biopsy with immunofluorescent studies should be considered in the diagnostic evaluation of such subjects, including those with idiopathic pulmonary haemosiderosis.