scholarly journals Deformation of membrane vesicles due to chiral surface proteins.

Soft Matter ◽  
2021 ◽  
Author(s):  
Arabinda Behera ◽  
Gaurav Kumar ◽  
Sk Ashif Akram ◽  
Anirban Sain
Keyword(s):  
Membrane Vesicles ◽  
Surface Proteins ◽  
Membrane Tubules ◽  
Chiral Surface

Chiral, rod-like molecules can self-assemble into cylindrical membrane tubules and helical ribbons. They have been successfully modeled using the theory of chiral nematics. Models have also predicted the role of...

scholarly journals Deformation of membrane vesicles due to chiral surface proteins

2021 ◽  
Author(s):  
Arabinda Behera ◽  
Gaurav Kumar ◽  
Sk Ashif Akram ◽  
Anirban Sain
Keyword(s):  
Membrane Vesicles ◽  
Membrane Curvature ◽  
Surface Proteins ◽  
Triangulated Surface ◽  
Chiral Nematic ◽  
Mc Simulation ◽  
Chiral Interaction ◽  
Fixed Cylinder ◽  
Chiral Surface

Chiral, rod-like molecules can self-assemble into cylindrical membrane tubules and helical ribbons. They have been successfully modeled using the theory of chiral nematics. Models have also predicted the role of chiral lipids in forming nanometer-sized membrane buds in the cell. However, in most theoretical studies, the membrane shapes are considered fixed (cylinder, sphere, saddle, etc.), and their optimum radius of curvatures are found variationally by minimizing the energy of the composite system consisting of membrane and chiral nematics. Numerical simulations have only recently started to consider membrane deformation and chiral orientation simultaneously. Here we examine how deformable, closed membrane vesicles and chiral nematic rods mutually influence each other's shape and orientation, respectively, using Monte-Carlo (MC) simulation on a closed triangulated surface. For this, we adopt a discrete form of chiral interaction between rods, originally proposed by Van der Meer et al. (1976) for off-lattice simulations. In our simulation, both conical and short cylindrical tubules emerge, depending on the strength of the chiral interaction and the intrinsic chirality of the molecules. We show that the Helfrich-Prost term, which couple nematic tilt with local membrane curvature in continuum models, can account for most of the observations in the simulation. At higher chirality, our theory also predicts chiral tweed phase on cones, with varying bandwidths.

scholarly journals Primary and Memory Response of Human Monocytes to Vaccines: Role of Nanoparticulate Antigens in Inducing Innate Memory

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 931
Author(s):  
Mayra M. Ferrari Ferrari Barbosa ◽  
Alex Issamu Kanno ◽  
Leonardo Paiva Farias ◽  
Mariusz Madej ◽  
Gergö Sipos ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Innate Immune ◽  
Soluble Form ◽  
Neisseria Lactamica ◽  
Particulate Form ◽  
Future Challenges ◽  
Monocytes And Macrophages

Innate immune cells such as monocytes and macrophages are activated in response to microbial and other challenges and mount an inflammatory defensive response. Exposed cells develop the so-called innate memory, which allows them to react differently to a subsequent challenge, aiming at better protection. In this study, using human primary monocytes in vitro, we have assessed the memory-inducing capacity of two antigenic molecules of Schistosoma mansoni in soluble form compared to the same molecules coupled to outer membrane vesicles of Neisseria lactamica. The results show that particulate challenges are much more efficient than soluble molecules in inducing innate memory, which is measured as the production of inflammatory and anti-inflammatory cytokines (TNFα, IL-6, IL-10). Controls run with LPS from Klebsiella pneumoniae compared to the whole bacteria show that while LPS alone has strong memory-inducing capacity, the entire bacteria are more efficient. These data suggest that microbial antigens that are unable to induce innate immune activation can nevertheless participate in innate activation and memory when in a particulate form, which is a notion that supports the use of nanoparticulate antigens in vaccination strategies for achieving adjuvant-like effects of innate activation as well as priming for improved reactivity to future challenges.

scholarly journals The mycoplasma surface proteins MIB and MIP promote the dissociation of the antibody-antigen interaction

2021 ◽  
Vol 7 (10) ◽  
pp. eabf2403
Author(s):  
Pierre Nottelet ◽  
Laure Bataille ◽  
Geraldine Gourgues ◽  
Robin Anger ◽  
Carole Lartigue ◽  
...  
Keyword(s):  
Surface Proteins ◽  
Mycoplasma Species ◽  
Antigen Binding ◽  
Antigen Binding Site ◽  
Fab Fragment ◽  
Cryo Electron Microscopy ◽  
Antigen Complex ◽  
Antigen Interaction ◽  
Immunoglobulin Binding

Mycoplasma immunoglobulin binding (MIB) and mycoplasma immunoglobulin protease (MIP) are surface proteins found in the majority of mycoplasma species, acting sequentially to capture antibodies and cleave off their VH domains. Cryo–electron microscopy structures show how MIB and MIP bind to a Fab fragment in a “hug of death” mechanism. As a result, the orientation of the VL and VH domains is twisted out of alignment, disrupting the antigen binding site. We also show that MIB-MIP has the ability to promote the dissociation of the antibody-antigen complex. This system is functional in cells and protects mycoplasmas from antibody-mediated agglutination. These results highlight the key role of the MIB-MIP system in immunity evasion by mycoplasmas through an unprecedented mechanism, and open exciting perspectives to use these proteins as potential tools in the antibody field.

scholarly journals The Prognostic Role of LRIG Proteins in Endometrial Cancer

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1361
Author(s):  
Zoia Razumova ◽  
Husam Oda ◽  
Igor Govorov ◽  
Eva Lundin ◽  
Ellinor Östensson ◽  
...  
Keyword(s):  
Overall Survival ◽  
Endometrial Cancer ◽  
Prognostic Factor ◽  
Confidence Interval ◽  
Initial Study ◽  
Surface Proteins ◽  
University Hospital ◽  
Study Cohort ◽  
Risk Of Death

Endometrial cancer (EC) is the most common gynecologic malignancy in Sweden and it has various prognostic factors. The LRIG family is a group of three integral surface proteins with a similar domain organization. The study aimed to explore LRIG family as prognostic factor proteins in EC. The initial study cohort included 100 women with EC who were treated at the Department of Women’s and Children’s Health, Karolinska University Hospital Solna, between 2007 and 2012. We assessed the associations between LRIG protein expression and type, grade, and stage of EC, as well as progression-free and overall survival. Immunohistochemistry results revealed that most women in the analytical sample had >50% LRIG1-, LRIG2- and LRIG3-positive cells. A statistically significant association was observed between having a high number of LRIG3-positive cells and superior overall survival (incidence rate ratio = 0.977; 95% confidence interval: 0.958–0.996, p = 0.019). Moreover, positive LRIG3 staining of the cell membrane was associated with reducing in the risk of death (hazard ratio = 0.23; 95% confidence interval: 0.09–0.57). Our results show that LRIG3 expression might be a prognostic factor in EC. The role of LRIG1 and LRIG2 expression remains to be further investigated.

Cell adhesion on chiral surface: The role of protein adsorption

2012 ◽  
Vol 90 ◽  
pp. 97-101 ◽  
Author(s):  
Feng Zhou ◽  
Lin Yuan ◽  
Dan Li ◽  
He Huang ◽  
Taolei Sun ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Protein Adsorption ◽  
Chiral Surface

scholarly journals The role of B7 family molecules in hematologic malignancy

Blood ◽  
2013 ◽  
Vol 121 (5) ◽  
pp. 734-744 ◽  
Author(s):  
Paul Greaves ◽  
John G. Gribben
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Immune Responses ◽  
Hematologic Malignancy ◽  
Surface Proteins ◽  
Cell Responses ◽  
Inducible Costimulator ◽  
Programmed Cell Death 1 ◽  
B7 Family

AbstractThe B7 family consists of structurally related, cell-surface proteins that regulate immune responses by delivering costimulatory or coinhibitory signals through their ligands. Eight family members have been identified to date including CD80 (B7-1), CD86 (B7-2), CD274 (programmed cell death-1 ligand [PD-L1]), CD273 (programmed cell death-2 ligand [PD-L2]), CD275 (inducible costimulator ligand [ICOS-L]), CD276 (B7-H3), B7-H4, and B7-H6. B7 ligands are expressed on both lymphoid and nonlymphoid tissues. The importance of the B7 family in regulating immune responses is clear from their demonstrated role in the development of immunodeficiency and autoimmune diseases. Manipulation of the signals delivered by B7 ligands shows great potential in the treatment of cancers including leukemias and lymphomas and in regulating allogeneic T-cell responses after stem cell transplantation.

Sign in / Sign up

Export Citation Format

Share Document