scholarly journals Snippets of virus integrated into human genome suggests possibility of CRISPR-like adaptive immune system in human cells

Author(s):  
Wenfa Ng

Snippets of virus that infect humans have been shown to be incorporated into the human genome. Could such virus snippets provide a form of adaptive immunity similar to that offered by CRISPR to bacterial cells? To answer the question, RNA-seq could be used to provide a broad view of the RNA transcribed from DNA in the genome. Using known genome sequence of viruses that infect humans as template, reads obtained from RNA-seq would be profiled for virus snippets integrated into human genome and subsequently transcribed as part of an adaptive immune system. Subsequently, viruses corresponding to the virus snippets in human genome would be used to infect human cell lines to obtain direct evidence of how virus snippets mediate an adaptive immune response at the cellular level. Specifically, successful defence of the cell by virus snippets triggering an adaptive immune response would manifest as viable cells compared to lysed cells unable to mount an immune response. Following demonstration of cell viability under viral challenge, in vitro biochemical assays using cell lysate would interrogate the specific proteins and enzymes that mediate possible cutting of the foreign DNA or RNA. To this end, beads immobilized with virus snippets would serve as bait for binding to complementary viral DNA or RNA as well as potential endogenous endonuclease protein. Following precipitation and recovery of beads, possible endonuclease that bind to both viral DNA or RNA and virus snippets immobilized on beads would be isolated through gel electrophoresis and subsequently purified. Purified endonuclease would be assayed for activity against a variety of nucleic acids (both DNA and RNA) from various sources with and without added virus snippets. This provides important information on substrate range and specificity of the potential endonuclease. Amino acid sequencing of the purified endonuclease would help downstream bioinformatic search for candidate protein in the human genome. Finally, cryo-electron microscopy could help determine the structure of the endonuclease in complex with viral nucleic acids and virus snippets. Such structural information would provide more insights into mechanistic details describing the binding and cleavage of viral DNA or RNA in a CRISPR-like adaptive immune response in human cells. Overall, tantalizing clues have emerged that a CRISPR-like adaptive immune response may exist in human cells for defending against viral attack. Combination of cell biological, biochemical and structural tools could lend insights into the potential endonuclease that mediate double strand break of foreign DNA or RNA using virus snippets transcribed from the human genome as guide RNA. If demonstrated to be true for a variety of human viruses across different cell lines, the newly discovered viral defence mechanism in human cells hold important implications for understanding the adoption and evolution of CRISPR in eukaryotic cells.

2019 ◽  
Author(s):  
Wenfa Ng

Snippets of virus that infect humans have been shown to be incorporated into the human genome. Could such virus snippets provide a form of adaptive immunity similar to that offered by CRISPR to bacterial cells? To answer the question, RNA-seq could be used to provide a broad view of the RNA transcribed from DNA in the genome. Using known genome sequence of viruses that infect humans as template, reads obtained from RNA-seq would be profiled for virus snippets integrated into human genome and subsequently transcribed as part of an adaptive immune system. Subsequently, viruses corresponding to the virus snippets in human genome would be used to infect human cell lines to obtain direct evidence of how virus snippets mediate an adaptive immune response at the cellular level. Specifically, successful defence of the cell by virus snippets triggering an adaptive immune response would manifest as viable cells compared to lysed cells unable to mount an immune response. Following demonstration of cell viability under viral challenge, in vitro biochemical assays using cell lysate would interrogate the specific proteins and enzymes that mediate possible cutting of the foreign DNA or RNA. To this end, beads immobilized with virus snippets would serve as bait for binding to complementary viral DNA or RNA as well as potential endogenous endonuclease protein. Following precipitation and recovery of beads, possible endonuclease that bind to both viral DNA or RNA and virus snippets immobilized on beads would be isolated through gel electrophoresis and subsequently purified. Purified endonuclease would be assayed for activity against a variety of nucleic acids (both DNA and RNA) from various sources with and without added virus snippets. This provides important information on substrate range and specificity of the potential endonuclease. Amino acid sequencing of the purified endonuclease would help downstream bioinformatic search for candidate protein in the human genome. Finally, cryo-electron microscopy could help determine the structure of the endonuclease in complex with viral nucleic acids and virus snippets. Such structural information would provide more insights into mechanistic details describing the binding and cleavage of viral DNA or RNA in a CRISPR-like adaptive immune response in human cells. Overall, tantalizing clues have emerged that a CRISPR-like adaptive immune response may exist in human cells for defending against viral attack. Combination of cell biological, biochemical and structural tools could lend insights into the potential endonuclease that mediate double strand break of foreign DNA or RNA using virus snippets transcribed from the human genome as guide RNA. If demonstrated to be true for a variety of human viruses across different cell lines, the newly discovered viral defence mechanism in human cells hold important implications for understanding the adoption and evolution of CRISPR in eukaryotic cells.


2021 ◽  
Vol 1 (30) ◽  
pp. 61-66
Author(s):  
V. P. Mudrov ◽  
N. V. Davidova ◽  
S. P. Kazakov ◽  
T. E. Mishina

Periodontal bacterial bioflm causes an innate and adaptive immune response of the host mucosa, leading to inflammation and destruction of the tissues supporting the periodontal. The progression of periodontitis depends not only on bacteria, since an inadequate immune response to microorganisms can accelerate the development of periodontitis. However, the exact mechanisms of the development of immune reactions remain unclear. Recent studies emphasize the existence of a typical innate response of resident and extravasated immune cells.Objective. To investigate the quantitative composition of non-resident subpopulations of lymphocytes in salivary fluid and to study the mechanisms of interaction of the cellular link of the innate and adaptive immune system in chronic generalized periodontitis of varying severity.Materials and methods. 49 people aged 26–67 years of both sexes were examined with a diagnosis of chronic periodontitis. The comparison group consisted of 17 people aged 26–44 years with no periodontal diseases. The state of the cellular link of the adaptive and local immune system of the oral cavity was assessed by the following phenotypes: CD3–CD16+56+; CD3+CD16+56+; CD3+; CD3+HLA-DR+; CD19+, CD19+HLA-DR+; CD19+CD5+CD27–; CD19+CD5–СD 27–; CD19+СD5–CD27+.Results. The number of T-NK cells decreased with a mild degree of periodontitis and increased with a severe degree. Similarly, CD3+HLA-DR+ decreased with mild periodontitis [Me = 0.148 cells/µl] and increased with moderate [Me = 0.247 cells/µl] and severe [Me = 0.448 cells/µl]. The number of B-lymphocytes with the CD19+, CD19+CD5+, CD19+CD5–CD27+ phenotype decreased to single cells per microliter during the development of the disease.Conclusion. The imbalance of the immune system caused by pathogenic colonization of the periodontium, at different degrees of severity, is an important factor in the occurrence and development of periodontitis, in which various subsets of B cells of the adaptive immune system play a certain role, closely interacting with the cellular link of the innate mucosal immune system


2005 ◽  
Vol 110 (1) ◽  
pp. 21-35 ◽  
Author(s):  
Steven E. Williams ◽  
Thomas I. Brown ◽  
Ali Roghanian ◽  
Jean-Michel Sallenave

Elafin and SLPI (secretory leucocyte protease inhibitor) have multiple important roles both in normal homoeostasis and at sites of inflammation. These include antiprotease and antimicrobial activity as well as modulation of the response to LPS (lipopolysaccharide) stimulation. Elafin and SLPI are members of larger families of proteins secreted predominantly at mucosal sites, and have been shown to be modulated in multiple pathological conditions. We believe that elafin and SLPI are important molecules in the controlled functioning of the innate immune system, and may have further importance in the integration of this system with the adaptive immune response. Recent interest has focused on the influence of inflamed tissues on the recruitment and phenotypic modulation of cells of the adaptive immune system and, indeed, the local production of elafin and SLPI indicate that they are ideally placed in this regard. Functionally related proteins, such as the defensins and cathelicidins, have been shown to have direct effects upon dendritic cells with potential alteration of their phenotype towards type I or II immune responses. This review addresses the multiple functions of elafin and SLPI in the inflammatory response and discusses further their roles in the development of the adaptive immune response.


2005 ◽  
Vol 201 (3) ◽  
pp. 321-323 ◽  
Author(s):  
Jorge E. Galán

Microorganisms that cause persistent infection often exhibit specific adaptations that allow them to avoid the adaptive immune response. Recently, several bacterial toxins have been shown in vitro to disrupt immune cell functions. However, it remains to be established whether these activities are relevant during infection and whether these toxins have specifically evolved to disrupt the adaptive immune system.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.H.J Staal ◽  
K.R.G Cortenbach ◽  
M.A.J Gorris ◽  
G.S.C Geuzebroek ◽  
L.J Wisse ◽  
...  

Abstract Background/Introduction Bicuspid aortic valve (BAV) is associated with ascending aorta aneurysms and dissections. Presently, genetic factors and pathological flow patterns are considered responsible for aneurysm formation in BAV. Despite, indication for preventive surgery is presently only defined by vessel diameter which is poor marker for dissection, as it does not take other processes responsible for the vulnerability of the aorta into account. Purpose Inflammation is not considered a player in BAV aortopathy. We introduce a quantitative immunohistochemistry (IHC) approach to sensitively look at the potential role of both the innate and adaptive immune system in BAV aortopathy. Methods Dilated (n=8), non-dilated (n=14) and dissected (n=4) BAV ascending aortas were collected during surgery or from post-mortem donors. Median time from symptoms to surgery for dissections was just over 4 hours. Tissue was stained with a novel 8-colour IHC technique allowing for simultaneous visualization of 6 markers per slide, completed with DAPI nuclear counter-stain and elastin fiber autofluorescence. One panel focused on the adaptive immune system (identifying B cells and classic dendritic cells type 2 (cDC2s) and phenotyping T cells), and the other on the innate immune system (assessing macrophage polarization and neutrophil extravasation). All cells were identified and comprehensively phenotyped using automated quantitative analysis. Results Aneurysm formation was associated with an organized and consistent increase of lymphocytes in the adventitia. B cell follicles and helper T cell expansion were identified, suggestive of a targeted adaptive immune response (Fig. 1a). Only dissected aortas showed a statistically significant increase of helper T (p=0.3) and cDC2s (p=0.3) in the media, when compared to non-dilated and dilated samples (Fig. 1b). The short time between dissection symptoms and surgery suggests these cells were present before the dissection occurred. Furthermore, aneurysms and dissections are associated with a shift in macrophage phenotype to the more aggressive M1-like subset. In summary, we found that a progression of aggressive immune cells in the adventitia and media was correlated to a progression in disease state; from normal to dilated to dissected. Conclusions Aorta dilatation in patients with BAV is associated with an expansion of B and helper T cells in the adventitial compartment without changes in the media. This result might indicate an antigen-driven adaptive immune response. Only dissections show an increase in helper T cells and cDC2s in the media, together with polarization of macrophages to a more M1-like phenotype. We hypothesize that antigen-specific helper T cells expand in the adventitia, migrate to the media, and then potentiate macrophages which can eventually lead to tissue degeneration. These associations could shine light on the final step in the deterioration of the aorta towards a dissection. Figure 1. Microscopy results Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): TTW-NWO open technology grant (STW-14716), ERC-2014-StG-336454-CoNQUeST


2012 ◽  
Vol 46 (5) ◽  
pp. 606-615 ◽  
Author(s):  
Dipali G. Sashital ◽  
Blake Wiedenheft ◽  
Jennifer A. Doudna

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1314 ◽  
Author(s):  
Sen ◽  
Almuslehi ◽  
Gyengesi ◽  
Myers ◽  
Shortland ◽  
...  

Cuprizone (CPZ) preferentially affects oligodendrocytes (OLG), resulting in demyelination. To investigate whether central oligodendrocytosis and gliosis triggered an adaptive immune response, the impact of combining a standard (0.2%) or low (0.1%) dose of ingested CPZ with disruption of the blood brain barrier (BBB), using pertussis toxin (PT), was assessed in mice. 0.2% CPZ(±PT) for 5 weeks produced oligodendrocytosis, demyelination and gliosis plus marked splenic atrophy (37%) and reduced levels of CD4 (44%) and CD8 (61%). Conversely, 0.1% CPZ(±PT) produced a similar oligodendrocytosis, demyelination and gliosis but a smaller reduction in splenic CD4 (11%) and CD8 (14%) levels and no splenic atrophy. Long-term feeding of 0.1% CPZ(±PT) for 12 weeks produced similar reductions in CD4 (27%) and CD8 (43%), as well as splenic atrophy (33%), as seen with 0.2% CPZ(±PT) for 5 weeks. Collectively, these results suggest that 0.1% CPZ for 5 weeks may be a more promising model to study the ‘inside-out’ theory of Multiple Sclerosis (MS). However, neither CD4 nor CD8 were detected in the brain in CPZ±PT groups, indicating that CPZ-mediated suppression of peripheral immune organs is a major impediment to studying the ‘inside-out’ role of the adaptive immune system in this model over long time periods. Notably, CPZ(±PT)-feeding induced changes in the brain proteome related to the suppression of immune function, cellular metabolism, synaptic function and cellular structure/organization, indicating that demyelinating conditions, such as MS, can be initiated in the absence of adaptive immune system involvement.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Luciana D’Apice ◽  
Valerio Costa ◽  
Rossella Sartorius ◽  
Maria Trovato ◽  
Marianna Aprile ◽  
...  

The filamentous bacteriophage fd, codisplaying antigenic determinants and a single chain antibody fragment directed against the dendritic cell receptor DEC-205, is a promising vaccine candidate for its safety and its ability to elicit innate and adaptive immune response in absence of adjuvants. By using a system vaccinology approach based on RNA-Sequencing (RNA-Seq) analysis, we describe a relevant gene modulation in dendritic cells pulsed with anti-DEC-205 bacteriophages fd. RNA-Seq data analysis indicates that the bacteriophage fd virions are sensed as a pathogen by dendritic cells; they activate the danger receptors that trigger an innate immune response and thus confer a strong adjuvanticity that is needed to obtain a long-lasting adaptive immune response.


2006 ◽  
Vol 291 (6) ◽  
pp. R1644-R1650 ◽  
Author(s):  
Paul C. Dimayuga ◽  
Xiaoning Zhao ◽  
Juliana Yano ◽  
Kuang-Yuh Chyu

Atherosclerosis is a disease associated with aging and is subject to modulation by both the innate and adaptive immune system. The time course of age-dependent changes in immune regulation in the context of atherosclerosis has not been characterized. This study aims to describe alteration of the immune responses to oxidized LDL (oxLDL) during aging that is associated with changes in plaque size and phenotype in apoE(−/−) mice. Mice fed a Western diet were euthanized at 15–17, 36, or >52 wk of age. The descending aortas were stained for assessment of extent of atherosclerosis. Plaque lipid, macrophage, and collagen content were evaluated in aortic sinus lesions. The adaptive immune response to oxLDL was assessed using anti-malondialdehyde-oxidized LDL (MDA-LDL) and copper-oxidized LDL (Cu-oxLDL) IgG, and the innate immune response was assessed using anti-Cu-oxLDL and phosphorylcholine (PC) IgM. Aging was associated with a significant increase in plaque area and collagen content and a decrease in plaque macrophage and lipid content. MDA-LDL IgG significantly increased at 36 wk but was reduced in mice >52 wk. Cu-oxLDL IgG increased with age and IgG-apoB immune complexes were increased in the >52 wk group. Cu-oxLDL and PC IgM significantly increased with age. The expression of splenic cytokines such as IFN-γ, IL-4, and IL-10 increased with age. Our study shows a generalized increase in innate immune responses associated with progression of atherosclerosis and a less inflammatory and less lipid-containing plaque phenotype during aging. The adaptive immune response appeared to be less generalized, with a specific reduction in MDA-LDL IgG.


2010 ◽  
Vol 28 (29) ◽  
pp. 4531-4538 ◽  
Author(s):  
Mary L. Disis

Innate and adaptive immune system cells play a major role in regulating the growth of cancer. Although it is commonly thought that an immune response localized to the tumor will inhibit cancer growth, it is clear that some types of inflammation induced in a tumor may also lead to cancer proliferation, invasion, and dissemination. Recent evidence suggests, however, that some patients with cancer can mount an antitumor immune response that has the potential to control or eliminate cancer. Indeed, a so-called “immune response” signature has been described in malignancy that is associated with improved outcomes in several tumor types. Moreover, the presence of specific subsets of T cells, which have the capability to penetrate tumor stroma and infiltrate deep into the parenchyma, identifies patients with an improved prognosis. Immune-based therapies have the potential to modulate the tumor microenvironment by eliciting immune system cells that will initiate acute inflammation that leads to tissue destruction.


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