scholarly journals Humoral Immune Responses to Amebic Liver Abscess

2021 ◽  
Vol 34 (1) ◽  
pp. 5-8
Author(s):  
KH Md Faisal Alam ◽  
Mohd Harun Or Rashid ◽  
Md Azizul Haque ◽  
Md Mahbubul Alam ◽  
MM Washee Parvez ◽  
...  

Background: Amebic liver abscess (ALA) is an ancient parasitic disease caused by E. histolytica described first by Hippocrates. It is endemic worldwide, mainly in tropic and subtropics countries. About 50 million true E. histolytica infections and approximately 100,000 deaths occur each year globally. In Bangladesh, exact incidences of amebic liver abscess cases are not estimated, but hospital reports indicate that it is endemic. Immunity and immune responses in acute and post infections of ALA are not well understood to date. However, the understanding of immunology is essential to know disease progression, recovery, morbidity, and mortality as well as diagnosis and newer prevention strategies like vaccine development. In this 15-month prospective and follow-up study, different antibody responses are estimated periodically. Methods: About 90 amebic liver abscess patients diagnosed initially by ultra-sonogram confirmed followed by Real-Time PCR were selected for this study. All were admitted into Rajshahi Medical College Hospital, Bangladesh. Antibody responses against different antigens, which include Serum anti-lectin IgG, Salivary anti-CRD (carbohydrate recognition domain) Ig A, and Stool anti-CRD (carbohydrate recognition domain) IgA were estimated by ELISA periodically thrice, in acute stage after 06 and 09 months and between 12 and 15 months. Results: Serum anti-lectin IgG in ALA persists remarkably high well up to 09 months in 98% cases, Secretory anti-CRD IgA was also determined from the saliva, and only 36(40%) show positive titer during first 06 months, and about 40% of ALA cases show high titer of anti-CRD IgA from stool samples in first six months of infection. Conclusion: Only serum anti lectin Ig G showed significant high titer in 98% of cases in the acute stage and up to nine months of infection. TAJ 2021; 34: No-1: 05-08

2021 ◽  
Vol 12 ◽  
Author(s):  
Lynda Mottram ◽  
Anna Lundgren ◽  
Ann-Mari Svennerholm ◽  
Susannah Leach

Vaccines against enteric diseases could improve global health. Despite this, only a few oral vaccines are currently available for human use. One way to facilitate such vaccine development could be to identify a practical and relatively low cost biomarker assay to assess oral vaccine induced primary and memory IgA immune responses in humans. Such an IgA biomarker assay could complement antigen-specific immune response measurements, enabling more oral vaccine candidates to be tested, whilst also reducing the work and costs associated with early oral vaccine development. With this in mind, we take a holistic systems biology approach to compare the transcriptional signatures of peripheral blood mononuclear cells isolated from volunteers, who following two oral priming doses with the oral cholera vaccine Dukoral®, had either strong or no vaccine specific IgA responses. Using this bioinformatical method, we identify TNFRSF17, a gene encoding the B cell maturation antigen (BCMA), as a candidate biomarker of oral vaccine induced IgA immune responses. We then assess the ability of BCMA to reflect oral vaccine induced primary and memory IgA responses using an ELISA BCMA assay on a larger number of samples collected in clinical trials with Dukoral® and the oral enterotoxigenic Escherichia coli vaccine candidate ETVAX. We find significant correlations between levels of BCMA and vaccine antigen-specific IgA in antibodies in lymphocyte secretion (ALS) specimens, as well as with proportions of circulating plasmablasts detected by flow cytometry. Importantly, our results suggest that levels of BCMA detected early after primary mucosal vaccination may be a biomarker for induction of long-lived vaccine specific memory B cell responses, which are otherwise difficult to measure in clinical vaccine trials. In addition, we find that ALS-BCMA responses in individuals vaccinated with ETVAX plus the adjuvant double mutant heat-labile toxin (dmLT) are significantly higher than in subjects given ETVAX only. We therefore propose that as ALS-BCMA responses may reflect the total vaccine induced IgA responses to oral vaccination, this BCMA ELISA assay could also be used to estimate the total adjuvant effect on vaccine induced-antibody responses, independently of antigen specificity, further supporting the usefulness of the assay.


2008 ◽  
Vol 82 (8) ◽  
pp. 4135-4148 ◽  
Author(s):  
Keith Mansfield ◽  
Sabine M. Lang ◽  
Marie-Claire Gauduin ◽  
Hannah B. Sanford ◽  
Jeffrey D. Lifson ◽  
...  

ABSTRACT An attenuated derivative of simian immunodeficiency virus strain 239 deleted of V1-V2 sequences in the envelope gene (SIV239ΔV1-V2) was used for vaccine/challenge experiments in rhesus monkeys. Peak levels of viral RNA in plasma of 104 to 106.5 copies/ml in the weeks immediately following inoculation of SIV239ΔV1-V2 were 10- to 1,000-fold lower than those observed with parental SIV239 (∼107.3 copies/ml). Viral loads consistently remained below 200 copies/ml after 8 weeks of infection by the attenuated SIV239ΔV1-V2 strain. Viral localization experiments revealed large numbers of infected cells within organized lymphoid nodules of the colonic gut-associated lymphoid tissue at 14 days; double-labeling experiments indicated that 93.5% of the virally infected cells at this site were positive for the macrophage marker CD68. Cellular and humoral immune responses measured principally by gamma interferon enzyme-linked immunospot and neutralization assays were variable in the five vaccinated monkeys. One monkey had responses in these assays comparable to or only slightly less than those observed in monkeys infected with parental, wild-type SIV239. Four of the vaccinated monkeys, however, had low, marginal, or undetectable responses in these same assays. These five vaccinated monkeys and three naïve control monkeys were subsequently challenged intravenously with wild-type SIV239. Three of the five vaccinated monkeys, including the one with strong anti-SIV immune responses, were strongly protected against the challenge on the basis of viral load measurements. Surprisingly, two of the vaccinated monkeys were strongly protected against SIV239 challenge despite the presence of cellular anti-SIV responses of low-frequency and low-titer anti-SIV antibody responses. These results indicate that high-titer anti-SIV antibody responses and high-frequency anti-SIV cellular immune responses measurable by standard assays from the peripheral blood are not needed to achieve strong vaccine protection, even against a difficult, neutralization-resistant strain such as SIV239.


mBio ◽  
2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Elena V. Vassilieva ◽  
Bao-Zhong Wang ◽  
Andrei N. Vzorov ◽  
Li Wang ◽  
Ying-Chun Wang ◽  
...  

ABSTRACTPreviously, a modified HIV Env protein with a heterologous membrane anchor was found to be incorporated into HIV virus-like particles (VLPs) at 10-fold-higher levels than those of unmodified Env. To further improve the immunogenicity of such VLPs, membrane-anchored forms of bacterial flagellin (FliC) or a flagellin with a truncated variable region (tFliC) were constructed to be incorporated into the VLPs as adjuvants. HIV-specific immune responses induced by the resulting VLPs were determined in a guinea pig model. The VLPs induce enhanced systemic antibody responses by either systemic or mucosal vaccination and enhanced mucosal immunity by a mucosal immunization route, as demonstrated by high levels of HIV-specific serum IgG and mucosal IgG and IgA. The quality of the antibody responses was also improved, as shown by enhanced neutralization capacity. VLPs incorporating FliC were more effective in inducing systemic responses, while VLPs containing tFliC were more effective in inducing mucosal IgA responses. The IgG titers in sera were found to last for at least 5 months without a significant drop. These results indicate that HIV VLPs incorporating high levels of Env and a molecular adjuvant have excellent potential for further development as a prophylactic HIV vaccine.IMPORTANCEA prophylactic vaccine is urgently needed to control the spread of HIV/AIDS. Antigens inducing strong systemic and mucosal immune responses are promising as vaccines for this mucosally transmitted disease. We found that novel HIV virus-like particles (VLPs) presenting a high level of Env in its native membrane-bound form and coincorporating an innate immune-signaling adjuvant in the same particles were effective in inducing enhanced systemic and mucosal immunity. As new HIV vaccine candidates, these VLPs bridge the gaps of the innate and adaptive, as well as systemic and mucosal, immune responses, providing a new approach for HIV vaccine development.


Parasitology ◽  
1996 ◽  
Vol 112 (S1) ◽  
pp. S39-S51 ◽  
Author(s):  
E. M. Riley

SUMMARYIndividual susceptibility to malaria infection, disease and death is influenced by host genotype, parasite virulence and a number of environmental factors including malaria-specific immunity. Immune responses are themselves determined by a combination of host genes and environmental effects. The extent to which host genotype limits the spectrum of possible immune responses may influence the outcome of infection and has consequences for vaccine design. Associations have been observed between human major histocompatibility complex (MHC) genotype and susceptibility to severe malaria, but no similar associations have been observed for mild malarial disease or for specific antibody responses to defined malaria antigens. Epidemiological studies have shown that, in practice, neither T helper cell nor antibody responses to malaria parasites are limited by host MHC genotype, but have revealed that genes lying outside the MHC may influence T cell proliferative responses. These genes have yet to be identified, but possible candidates include T cell receptor (TcR) genes, and genes involved in TcR gene rearrangements. More importantly, perhaps, longitudinal epidemiological studies have shown that the anti-malarial antibody repertoire is selective and becomes fixed in malaria-immune individuals, but is independent of host genotype. These findings suggest that the antibody repertoire may be determined, at least in part, by stochastic events. The first of these is the generation of the T and B cell repertoire, which results from random gene recombinations and somatic mutation and is thus partially independent of germline genes. Secondly, of the profusion of immunogenic peptides which are processed and presented by antigen presenting cells, a few will, by chance, interact with T and B cell surface antigen receptors of particularly high affinity. These T and B cell clones will be selected, will expand and may come to dominate the immune response, preventing the recognition of variant epitopes presented by subsequent infections - a process known as original antigenic sin or clonal imprinting. The immune response of an individual thus reflects the balance between genetic and stochastic effects. This may have important consequences for subunit vaccine development.


2015 ◽  
Vol 23 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Subhra Chakraborty ◽  
Clayton Harro ◽  
Barbara DeNearing ◽  
Malathi Ram ◽  
Andrea Feller ◽  
...  

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) bacteria are the most common bacterial cause of diarrhea in children in resource-poor settings as well as in travelers. Although there are several approaches to develop an effective vaccine for ETEC, no licensed vaccines are currently available. A significant challenge to successful vaccine development is our poor understanding of the immune responses that correlate best with protection against ETEC illness. In this study, ETEC-specific mucosal immune responses were characterized and compared in subjects challenged with ETEC strain H10407 and in subjects rechallenged with the homologous organism. IgA responses to lipopolysaccharide (LPS), heat-labile toxin B subunit (LTB), and colonization factor antigen I (CFA/I) in antibody in lymphocyte supernatant (ALS), feces, lavage fluid, and saliva samples were evaluated. In all assay comparisons, ALS was the most sensitive indicator of a local immune response, but serum IgA was also a useful indirect marker of immune response to oral antigens. Volunteers challenged and then rechallenged with strain H10407 were protected from illness following rechallenge. Comparing mucosal antibody responses after primary and homologous rechallenge, protection against disease was reflected in reduced antibody responses to key ETEC antigens and in reduced fecal shedding of the H10407 challenge strain. Subjects challenged with strain H10407 mounted stronger antibody responses to LPS and LTB than subjects in the rechallenge group, while responses to CFA/I in the rechallenge group were higher than in the challenge group. We anticipate that this study will help provide an immunological benchmark for the evaluation of ETEC vaccines and immunization regimens in the future.


npj Vaccines ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Stephanie Longet ◽  
Aine Abautret-Daly ◽  
Christopher J. H. Davitt ◽  
Craig P. McEntee ◽  
Vincenzo Aversa ◽  
...  

Abstract Helicobacter pylori causes chronic gastric infection that can lead to peptic ulcers and is an identified risk factor for gastric cancer development. Although much effort has been put into the development of a Helicobacter pylori vaccine over the last three decades, none has yet reached clinical application. Specific challenges pertaining to effective H. pylori vaccine development include the lack of proven vaccine-effective antigens and safe mucosal adjuvants to enhance local immune responses as well as the lack of accepted correlates of protection. Herein, we demonstrate that prophylactic intragastric immunisation with a whole-cell killed H. pylori antigen administered together with the non-toxic oral adjuvant α-galactosylceramide (α-GalCer) induced effective immune protection against H. pylori infection in mice, which was of similar magnitude as when using the “gold standard” cholera toxin as adjuvant. We further describe that this α-GalCer-adjuvanted vaccine formulation elicited strong intestinal and systemic Th1 responses as well as significant antigen-specific mucosal and systemic antibody responses. Finally, we report that the protective intestinal Th1 responses induced by α-GalCer are dependent on CD1d, IL-1R as well as IL-17R signalling. In summary, our results show that α-GalCer is a promising adjuvant for inclusion in an oral vaccine against H. pylori infection.


2021 ◽  
pp. 1-55
Author(s):  
Siu Wa Tang ◽  
Daiga Helmeste ◽  
Brian Leonard

Abstract Neuropsychiatric sequalae to COVID-19 infection are beginning to emerge, like previous Spanish influenza and SARS episodes. Streptococcal infection in pediatric patients causing OCD (PANDAS) is another recent example of an infection-based psychiatric disorder. Inflammation associated with neuropsychiatric disorders has been previously reported but there is no standard clinical management approach established. Part of the reason is that it is unclear what factors determine the specific neuronal vulnerability and the efficacy of anti-inflammatory treatment in neuroinflammation. The emerging COVID-19 data suggested that in the acute stage, wide-spread neuronal damage appears to be the result of abnormal and overactive immune responses and cytokine storm is associated with poor prognosis. It is still too early to know if there are long term specific neuronal or brain regional damages associated with COVID-19, resulting in distinct neuropsychiatric disorders. In several major psychiatric disorders where neuroinflammation is present, patients with abnormal inflammatory markers may also experience less than favorable response or treatment resistance when standard treatment is used alone. Evidence regarding the benefits of co-administered anti-inflammatory agents such as COX-2 inhibitor is encouraging in selected patients though may not benefit others. Disease modifying therapies are increasingly being applied to neuropsychiatric diseases characterized by abnormal or hyperreactive immune responses. Adjunct anti-inflammatory treatment may benefit selected patients and is definitely an important component of clinical management in the presence of neuroinflammation.


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