scholarly journals Significant control of Zika infection in macaques depends on the elapsing time after dengue exposure

2019 ◽  
Author(s):  
Crisanta Serrano-Collazo ◽  
Erick X. Pérez-Guzmán ◽  
Petraleigh Pantoja ◽  
Mariah A. Hassert ◽  
Idia V. Rodríguez ◽  
...  

AbstractPrior exposure to a single serotype of dengue virus (DENV) predisposes individuals to severe disease upon secondary heterologous DENV infection. Here we show that the length of time between DENV/Zika (ZIKV) infections has a qualitative impact on controlling ZIKV replication. We identified limited but significant differences in the magnitude of the early humoral immune response associated with a period of twelve months but not three months of DENV convalescence. However, their role limiting ZIKV replication is not conclusive. There was no evidence of in vivo antibody-dependent amplification of ZIKV by DENV immunity in any group. We are also showing that the significant differences among groups may be linked to a pre-existing polyfunctional CD4+ T cells response (increased IFN-g and Cd107a before ZIKV infection) and to an early and continuous expansion of the CD4+ effector memory cells early on after ZIKV infection. Those significant differences were associated with a period of 12 months after DENV infection that were not observed in a span of 3-months. These results suggest that there is a window of optimal cross-protection between ZIKV and DENV with significant consequences. These results have pivotal implications while interpreting ZIKV pathogenesis in flavivirus-experimented populations, diagnostic results interpretation and vaccine designs among others.Author SummarySince its introduction in the Americas region ZIKV virus has been associated to severe birth defects. One of the questions that remains open is the role of previous dengue or any other flavivirus immunity in the pathogenesis of ZIKV and more important, if the time elapse between DENV and ZIKV play a role enhancing ZIKV pathogenesis as it is the case for subsequent DENV infections. On this work, using NHP as a model we compared the effect of a period of 12 months vs. a period of 3 months of DENV immunity in the outcome of ZIKV infection. We found that previous DENV infection, at any of the tested period of time do not induce ZIKV enhancement. More relevant are showing that when the two infection occurs at least one year apart the preexisting DENV immunity is better at controlling ZIKV replication and that the role of the neutralizing antibodies is very limited. On the contrary our results suggest that early after ZIKV infection the cellular immune response, may plays a predominant role. Our findings have critical relevance to understand the dynamic interaction between these two flavivirus, their pathogenies, diagnosis and vaccine design.

1976 ◽  
Vol 143 (1) ◽  
pp. 73-84 ◽  
Author(s):  
B Chesebro ◽  
K Wehrly

The humoral immune response to Friend virus leukemia was studied in congenic F1 mice differing in their incidence of recovery from leukemia. Antiviral neutralizing antibodies rose in titer in vivo concurrently with disappearance of viremia and fall in spleen virus levels. Cytotoxic antileukemia cell antibodies also appeared at this time. Passive transfer of these antibodies could inactivate low numbers of leukemia cells in vivo; however, mice of both high and low recovery genotypes produced antibodies in equal titer and recovered from viral infection in spite of striking differences in recovery from leukemic splenomegaly. Mice lacking C57BL genes did not produce antibodies or recover from viremia except in rare instances. Recovery from splenomegaly was found to be influenced by three or more C57BL genes independent of the H-2 complex.


2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Chhaya Pirta ◽  
Nitya Nand Sharma ◽  
H.S. Banyal

AbstractIntraerythrocytic parasites degrade haemoglobin to make available nutrients for their growth and maturation. Plasmepsins, the aspartic proteases of Plasmodium play a significant role in haemoglobin degradation and are proposed as attractive drug targets. In the present study the gene which encodes plasmepsin in rodent malaria parasite, Plasmodium berghei, was cloned and expressed. The gene was sequenced and expressed in Escherichia coli BL21DE3 and a recombinant plasmepsin of molecular weight 43 kDa was obtained. The sequence obtained was analysed and compared with plasmepsins of other Plasmodium spp. Mice immunized with the recombinant plasmepsin induced a strong humoral immune response. ELISA and IFA performed on the serum of immunized mice showed high antibody titres. Along with this, in vivo study exhibited partial protection against P. berghei infection suggesting role of plasmepsin in malaria control.


2009 ◽  
Vol 54 (3) ◽  
pp. 239-245 ◽  
Author(s):  
J. M. L. Maia ◽  
L. G. S. Monnazzi ◽  
B. M. M. Medeiros

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Meilin Chan ◽  
Licun Wu ◽  
Zhihong Yun ◽  
Trevor D. McKee ◽  
Michael Cabanero ◽  
...  

AbstractMalignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.


2021 ◽  
Vol 22 (7) ◽  
pp. 3687
Author(s):  
Joanna Homa ◽  
Alina Klosowska ◽  
Magdalena Chadzinska

Arginase is the manganese metalloenzyme catalyzing the conversion of l-arginine to l-ornithine and urea. In vertebrates, arginase is involved in the immune response, tissue regeneration, and wound healing and is an important marker of alternative anti-inflammatory polarization of macrophages. In invertebrates, data concerning the role of arginase in these processes are very limited. Therefore, in the present study, we focused on the changes in arginase activity in the coelomocytes of Eisenia andrei. We studied the effects of lipopolysaccharide (LPS), hydrogen peroxide (H2O2), heavy metals ions (e.g., Mn2+), parasite infection, wound healing, and short-term fasting (5 days) on arginase activity. For the first time in earthworms, we described arginase activity in the coelomocytes and found that it can be up-regulated upon in vitro stimulation with LPS and H2O2 and in the presence of Mn2+ ions. Moreover, arginase activity was also up-regulated in animals in vivo infected with nematodes or experiencing segment amputation, but not in fasting earthworms. Furthermore, we confirmed that the activity of coelomocyte arginase can be suppressed by l-norvaline. Our studies strongly suggest that similarly to the vertebrates, also in the earthworms, coelomocyte arginase is an important element of the immune response and wound healing processes.


2021 ◽  
Author(s):  
Emily Stephenson ◽  
◽  
Gary Reynolds ◽  
Rachel A. Botting ◽  
Fernando J. Calero-Nieto ◽  
...  

AbstractAnalysis of human blood immune cells provides insights into the coordinated response to viral infections such as severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19). We performed single-cell transcriptome, surface proteome and T and B lymphocyte antigen receptor analyses of over 780,000 peripheral blood mononuclear cells from a cross-sectional cohort of 130 patients with varying severities of COVID-19. We identified expansion of nonclassical monocytes expressing complement transcripts (CD16+C1QA/B/C+) that sequester platelets and were predicted to replenish the alveolar macrophage pool in COVID-19. Early, uncommitted CD34+ hematopoietic stem/progenitor cells were primed toward megakaryopoiesis, accompanied by expanded megakaryocyte-committed progenitors and increased platelet activation. Clonally expanded CD8+ T cells and an increased ratio of CD8+ effector T cells to effector memory T cells characterized severe disease, while circulating follicular helper T cells accompanied mild disease. We observed a relative loss of IgA2 in symptomatic disease despite an overall expansion of plasmablasts and plasma cells. Our study highlights the coordinated immune response that contributes to COVID-19 pathogenesis and reveals discrete cellular components that can be targeted for therapy.


2009 ◽  
Vol 83 (7) ◽  
pp. 3228-3237 ◽  
Author(s):  
François-Loic Cosset ◽  
Philippe Marianneau ◽  
Geraldine Verney ◽  
Fabrice Gallais ◽  
Noel Tordo ◽  
...  

ABSTRACT The cell entry and humoral immune response of the human pathogen Lassa virus (LV), a biosafety level 4 (BSL4) Old World arenavirus, are not well characterized. LV pseudoparticles (LVpp) are a surrogate model system that has been used to decipher factors and routes involved in LV cell entry under BSL2 conditions. Here, we describe LVpp, which are highly infectious, with titers approaching those obtained with pseudoparticles displaying G protein of vesicular stomatitis virus and their the use for the characterization of LV cell entry and neutralization. Upon cell attachment, LVpp utilize endocytic vesicles for cell entry as described for many pH-dependent viruses. However, the fusion of the LV glycoproteins is activated at unusually low pH values, with optimal fusion occurring between pH 4.5 and 3, a pH range at which fusion characteristics of viral glycoproteins have so far remained largely unexplored. Consistent with a shifted pH optimum for fusion activation, we found wild-type LV and LVpp to display a remarkable resistance to exposure to low pH. Finally, LVpp allow the fast and quantifiable detection of neutralizing antibodies in human and animal sera and will thus facilitate the study of the humoral immune response in LV infections.


2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 284
Author(s):  
Hulda R. Jonsdottir ◽  
Michel Bielecki ◽  
Denise Siegrist ◽  
Thomas W. Buehrer ◽  
Roland Züst ◽  
...  

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults.


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