scholarly journals CD20-Mimotope Peptides: A Model to Define the Molecular Basis of Epitope Spreading

2019 ◽  
Vol 20 (8) ◽  
pp. 1920 ◽  
Author(s):  
Elvira Favoino ◽  
Marcella Prete ◽  
Giacomo Catacchio ◽  
Giuseppina Conteduca ◽  
Federico Perosa
Keyword(s):  
Molecular Basis ◽  
Peptide Binding ◽  
Active Immunotherapy ◽  
Epitope Spreading ◽  
Peptide Vaccination ◽  
Additional Mechanism ◽  
Linear Peptide ◽  
Nominal Antigen ◽  
The One ◽  
Anti Cd20

Antigen-mimicking peptide (mimotope)-based vaccines are one of the most promising forms of active-immunotherapy. The main drawback of this approach is that it induces antibodies that react poorly with the nominal antigen. The aim of this study was to investigate the molecular basis underlying the weak antibody response induced against the naïve protein after peptide vaccination. For this purpose, we analyzed the fine specificity of monoclonal antibodies (mAb) elicited with a 13-mer linear peptide, complementary to theantigen-combining site of the anti-CD20 mAb, Rituximab, in BALB/c mice. Anti-peptide mAb competed with Rituximab for peptide binding. Even so, they recognized a different antigenic motif from the one recognized by Rituximab. This explains their lack of reactivity with membrane (naïve) CD20. These data indicate that even on a short peptide the immunogenic and antigenic motifs may be different. These findings highlight an additional mechanism for epitope spreading and should be taken into account when designing peptides for vaccine purposes.

scholarly journals Mapping Peptide-binding Domains of the Human V1a Vasopressin Receptor with a Photoactivatable Linear Peptide Antagonist

1997 ◽  
Vol 272 (42) ◽  
pp. 26536-26544 ◽  
Author(s):  
Sylvie Phalipou ◽  
Nathalie Cotte ◽  
Eric Carnazzi ◽  
René Seyer ◽  
Eve Mahe ◽  
...  
Keyword(s):  
Peptide Binding ◽  
Vasopressin Receptor ◽  
Linear Peptide ◽  
Binding Domains ◽  
Peptide Antagonist

Molecular Basis of the Activity of Antibiotics of the Vancomycin Group: Guides for Peptide–Peptide Binding

1990 ◽  
pp. 101-113
Author(s):  
DUDLEY H. WILLIAMS ◽  
ANDREW J. DOIG ◽  
JONATHAN P.L. COX ◽  
IAN A. NICHOLLS ◽  
MARK GARDNER
Keyword(s):  
Molecular Basis ◽  
Peptide Binding ◽  
Vancomycin Group

CD20 Mimicry by a mAb Rituximab-Specific Linear Peptide: A Potential Tool for Active Immunotherapy of Autoimmune Diseases

2005 ◽  
Vol 1051 (1) ◽  
pp. 672-683 ◽  
Author(s):  
FEDERICO PEROSA ◽  
ELVIRA FAVOINO ◽  
MARIA ANTONIETTA CARAGNANO ◽  
FRANCO DAMMACCO
Keyword(s):  
Autoimmune Diseases ◽  
Active Immunotherapy ◽  
Linear Peptide ◽  
Potential Tool

R603: A New Low Dose Efficient Anti-CD20 Immunotherapy for CLL Patients ?

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4155-4155
Author(s):  
Magali Le Garff-Tavernier ◽  
Julie Decocq ◽  
Christophe de Romeuf ◽  
Jean-Luc Teillaud ◽  
Charles-Antoine Dutertre ◽  
...  
Keyword(s):  
B Cells ◽  
Nk Cells ◽  
Low Dose ◽  
Surface Expression ◽  
Raji Cells ◽  
Healthy Donors ◽  
The One ◽  
Anti Cd20 ◽  
Functional Capacities

Abstract Immunotherapy with monoclonal antibodies (mAbs), such as anti-CD20, is used in CLL treatment and represents a promising approach for achieving MRD eradication. Given their FcγRIIIa expression, NK cells are known to be involved in mAb therapy. We previously conducted a complete NK cells phenotypic expertise and functional assays including cytotoxicity against K562 cell line and antibody-dependent cellular cytotoxicity (ADCC) with rituximab, showing no major differences between NK cells from CLL patients and NK cells from healthy donors. We are now interested in functional capacities of NK cells in presence or not of a new anti-CD20 mAb: R603, a chimeric anti-CD20 mAb exhibiting a low fucose content as described for EMAB-6 mAb (C. de Romeuf et al, BJH 2008) in comparison to rituximab. To assess the degranulation of NK cells from CLL patients in response to anti-CD20 mAbs, we examined the surface expression of CD107a (percentage of CD107a+ NK cells) after co-incubation of PBMC from untreated CLL patients (n=8) with Raji cells (E/T ratio: 1/1) at 2 concentrations of each anti-CD20 mAb (10 and 1,000 ng/ml). At the higher mAb dose (1,000 ng/ml), R603 related degranulation of CLL NK cells (median (m): 43.6%; range (r): 27.0–79.8) was similar to the one obtained with rituximab (m: 38.9%; r: 22.4–75.2). At the lower dose (10 ng/ml), R603 related degranulation of CLL NK cells (m: 45.7%; r: 28.7–79.2) was similar to the one obtained with the high mAb concentration, contrary to rituximab related degranulation which was significantly decreased (m: 14.1%; r: 1.4–45.4) (p<0.0001). These results are emphasized by ADCC chromium assay performed with purified CLL NK cells (E/T ratio: 5/1 and 10/1) against Raji cells and with or without anti-CD20 mAbs (at 3 doses: 1, 10 and 1,000 ng/ml). R603 related ADCC levels were high whatever the mAb concentration, contrary to rituximab related ADCC levels which were very low at 1 ng/ml and only reached R603 ADCC levels at 1,000 ng/ml. Similar results were obtained with healthy donors. Without addition of Raji cells (CLL PBMC + mAb), at the lower dose (10 ng/ml), none of the NK cells from CLL patients exhibited degranulation with rituximab, contrary to R603 where 5/8 CLL patients exhibited degranulation (cut-off: more than 10% of CD107a+ NK cells). At the higher dose (1,000 ng/ml), NK cells from 6/8 CLL patients with rituximab and from 7/8 CLL patients with R603 showed degranulation and R603 related degranulation levels (m: 32.3%, r: 0.8–51.0) were significantly superior to rituximab related degranulation levels (m: 12.1%, r: 0.1–30.6) (p=0.0005). These results showed that R603 in the presence of CLL B cells might induce CLL NK degranulation. In conclusion, NK cells from CLL patients appeared to be capable of being efficient in anti-CD20 immunotherapy by the ADCC pathway. Moreover, R603 a new anti-CD20 mAb, induced at low dose a significantly higher in vitro ADCC against Raji cells and autologous CLL B cells, compared to rituximab. This R603 mAb feature may be useful in therapeutic strategy for CLL patients.

scholarly journals Lipoarabinomannans: characterization of the multiacylated forms of the phosphatidyl-myo-inositol anchor by NMR spectroscopy

1999 ◽  
Vol 337 (3) ◽  
pp. 453-460 ◽  
Author(s):  
Jérôme NIGOU ◽  
Martine GILLERON ◽  
Germain PUZO
Keyword(s):  
Molecular Basis ◽  
Quantum Correlation ◽  
Analytical Approach ◽  
31P Nmr ◽  
Multiple Quantum ◽  
Double Negative ◽  
Bacillus Calmette Guerin ◽  
One Dimensional ◽  
The One

Lipoarabinomannans, which exhibit a large spectrum of immunological activities, emerge as the major antigens of mycobacterial envelopes. The lipoarabinomannan structure is based on a phosphatidyl-myo-inositol anchor whose integrity has been shown to be crucial for lipoarabinomannan biological activity and particularly for presentation to CD4/CD8 double-negative αβT cells by CD1 molecules. In this report, an analytical approach was developed for high-resolution 31P-NMR analysis of native, i.e. multiacylated, lipoarabinomannans. The one-dimensional 31P spectrum of cellular lipoarabinomannans, from Mycobacterium bovis Bacillus Calmette–Guérin, exhibited four 31P resonances typifying four types of lipoarabinomannans. Two-dimensional 1H-31P heteronuclear multiple-quantum-correlation/homonuclear Hartmann–Hahn analysis of the native molecules showed that these four types of lipoarabinomannan differed in the number and localization of fatty acids (from 1 to 4) esterifying the anchor. Besides the three acylation sites previously described, i.e. positions 1 and 2 of glycerol and 6 of the mannosyl unit linked to the C-2 of myo-inositol, we demonstrate the existence of a fourth acylation position at the C-3 of myo-inositol. We report here the first structural study of native multiacylated lipoarabinomannans, establishing the structure of the intact phosphatidyl-myo-inositol anchor. Our findings would help gain more understanding of the molecular basis of lipoarabinomannan discrimination in the binding process to CD1 molecules.

Generation of biologically active linear and cyclic peptides has revealed a unique fine specificity of rituximab and its possible cross-reactivity with acid sphingomyelinase-like phosphodiesterase 3b precursor

Blood ◽  
2006 ◽  
Vol 107 (3) ◽  
pp. 1070-1077 ◽  
Author(s):  
Federico Perosa ◽  
Elvira Favoino ◽  
Maria Antonietta Caragnano ◽  
Franco Dammacco
Keyword(s):  
Cyclic Peptides ◽  
Cross Reactivity ◽  
Acid Sphingomyelinase ◽  
Biologically Active ◽  
Active Immunotherapy ◽  
Effector Functions ◽  
Fine Specificity ◽  
Phage Display Peptide Library ◽  
Phosphodiesterase 3B ◽  
Anti Cd20

Abstract Heterogeneity of the effector functions displayed by rituximab and other anti-CD20 monoclonal antibodies (mAbs) apparently recognizing the same CD20 epitope suggests that additional mechanisms, probably related to mAb fine specificity, are responsible for B-cell depletion. To improve our understanding of rituximab's function, its fine specificity was investigated by means of phage display peptide library (PDPL)-expressing 7-mer cyclic (c7c) or 7-/12-mer linear peptides. Rituximab-specific c7c PDPL-derived clone insert sequences expressed the motif A(S)NPS overlapping the human CD20 170ANPS173. P172 was the most critical for rituximab binding, since its replacement with S172 (of mouse CD20) abolished the reactivity. The WPXWLE motif expressed by the linear PDPL-derived clone insert sequences could only be aligned to the reverse-oriented 161WPXWLE156 of acid sphingomyelinase-like phosphodiesterase 3b precursor (ASMLPD), though linear peptides bearing WPXWLE competed with cyclic ones for rituximab-paratope binding. Anti-CD20 mAb 1F5 only displayed a reactivity profile similar to that of rituximab, which also reacted with ASMLPD-derived peptides. Peptides induced antibodies with specificity and effector functions similar to those of rituximab. Our results show a unique fine specificity of rituximab, define the molecular basis for the lack of rituximab reactivity with mouse CD20 (mCD20), and the potential of targeting CD20 in an active immunotherapy setting. A possible rituximab interaction with ASMLPD is suggested.

scholarly journals Conservation of specificity in two low-specificity protein

2017 ◽  
Author(s):  
Lucas C. Wheeler ◽  
Jeremy A. Anderson ◽  
Anneliese J. Morrison ◽  
Caitlyn E. Wong ◽  
Michael J. Harms
Keyword(s):  
Peptide Binding ◽  
Binding Specificity ◽  
Titration Calorimetry ◽  
Last Common Ancestor ◽  
Linear Peptide ◽  
Peptide Binding Specificity ◽  
Binding Interface ◽  
Sequence Reconstruction ◽  
Biochemical Approach ◽  
Specificity Protein

AbstractS100 proteins bind linear peptide regions of target proteins and modulate their activity. The peptide binding interface, however, has remarkably low specificity and can interact with many target peptides. It is not clear if the interface discriminates targets in a biological context, or whether biological specificity is achieved exclusively through external factors such as subcellular localization. To discriminate these possibilities, we used an evolutionary biochemical approach to trace the evolution of paralogs S100A5 and S100A6. We first used isothermal titration calorimetry to study the binding of a collection of peptides with diverse sequence, hydrophobicity, and charge to human S100A5 and S100A6. These proteins bound distinct, but overlapping, sets of peptide targets. We then studied the peptide binding properties of S100A5 and S100A6 orthologs sampled from across five representative amniote species. We found that the pattern of binding specificity was conserved along all lineages, for the last 320 million years, despite the low specificity of each protein. We next used Ancestral Sequence Reconstruction to determine the binding specificity of the last common ancestor of the paralogs. We found the ancestor bound the whole set of peptides bound by modern S100A5 and S100A6 proteins, suggesting that paralog specificity evolved by subfunctionalization. To rule out the possibility that specificity is conserved because it is difficult to modify, we identified a single historical mutation that, when reverted in human S100A5, gave it the ability to bind an S100A6-specific peptide. These results indicate that there are strong evolutionary constraints on peptide binding specificity, and that, despite being able to bind a large number of targets, the specificity of S100 peptide interfaces is indeed important for the biology of these proteins.

Stability and Peptide Binding Specificity of BTK SH2 Domain: Molecular Basis for X-Linked Agammaglobulinemia

2001 ◽  
pp. 967-968
Author(s):  
Shiou-Ru Tzeng ◽  
Ming-Tao Pai ◽  
Feng-Di T. Lung ◽  
Peter P. Roller ◽  
Benfang Lei ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Peptide Binding ◽  
Binding Specificity ◽  
Sh2 Domain ◽  
Peptide Binding Specificity

Rituximab Produces Long-Term Responses in Immune Thrombocytopenic Purpura (ITP).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3977-3977 ◽  
Author(s):  
Delvyn C. Case ◽  
Jacquelyn A. Hedlund ◽  
Kurt S. Ebrahim ◽  
Marjorie A. Boyd
Keyword(s):  
Immune Thrombocytopenic Purpura ◽  
Patient Characteristics ◽  
Complete Response ◽  
Initial Therapy ◽  
Thrombocytopenic Purpura ◽  
Platelet Counts ◽  
Number Of Patients ◽  
The One ◽  
Anti Cd20

Abstract ITP in adults is an autoimmune disease characterized by antibody-mediated thrombocytopenia. A significant number of patients relapse after initial therapy with prednisone and splenectomy when necessary, and require other therapy for continuing thrombocytopenia. Rituximab, an anti-CD20 chimeric monoclonal antibody has been utilized in ITP refractory to other modes of treatment (Feurestein, M., et al. The use of Rituximab in 28 patients with immune thrombocytopenic purpura (ITP). Proc. Am. Soc. Clin. Onc.22:187, 2003). We report on the long-term responses possible in ITP treated with Rituximab. Twenty-two patients with ITP refractory to initial conventional therapies with platelet counts <30,000/ul were treated with Rituximab 375 mg/m2 IV weekly x4. Responses were characterized as partial response (PR; platelets >50,000/ul but <150,000/ul) and complete response (platelets >150,000/ul). Patient characteristics included 5 males and 17 females with ages 24–83 years (median 58). Twenty had undergone splenectomy. Thirteen patients (59%) responded to Rituximab. Six responses were PR with durations lasting 2, 2, 3, 3, 4, and 6 months. Continuing Rituximab monthly after initial therapy of 4 weeks did not produce improved platelet counts in patients who failed Rituximab or who achieved PR. Seven responses were CR with durations of 12, 20+, 25+, 29+, 38+, 40+, and 48+ months. The one patient who relapsed at 12 months was retreated with Rituximab but did not respond. There was no correlation between response and age, sex, or duration of ITP. Neither of the patients who declined prior splenectomy responded. There were no serious complications of Rituximab infusions. Twenty-five percent of patients had mild first infusion reactions. Rituximab can produce long-term CR in 27% of patients with ITP refractory to initial therapy.

scholarly journals Interdomain communication in the molecular chaperone DnaK

2003 ◽  
Vol 369 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Wanjiang HAN ◽  
Philipp CHRISTEN
Keyword(s):  
Substrate Binding ◽  
Peptide Binding ◽  
Binding Domain ◽  
Intrinsic Fluorescence ◽  
Tryptophan Residue ◽  
Atpase Domain ◽  
Chaperone Dnak ◽  
The One ◽  
Kinetics Of ◽  
Substrate Binding Domain

DnaK, a heat-shock protein 70 (Hsp70) homologue in Escherichia coli, possesses a single tryptophan residue in its ATPase domain. Changes in the intrinsic fluorescence of DnaK offer a simple means not only to follow the binding of ATP and of ADP plus the co-chaperone GrpE to the ATPase domain, but also to investigate the kinetics of peptide binding to the substrate-binding domain of ATP·DnaK and GrpE-liganded ADP·DnaK. Addition of ATP or of ADP plus GrpE to nucleotide-free DnaK resulted in a similar decrease in intrinsic fluorescence, indicating similar open conformations of the ATPase domain under these two conditions. Binding of peptide increased the intrinsic fluorescence of both ATP·DnaK and ADP·DnaK·GrpE and rendered their spectra similar to the spectrum of ADP·DnaK with closed conformation of the ATPase domain. These results, together with the differential kinetics of peptide binding to ADP·DnaK on the one hand, and to ATP·DnaK or ADP·DnaK·GrpE on the other, suggest that ligands for either domain, i.e. ATP or ADP plus GrpE for the ATPase domain and peptides for the substrate-binding domain, shift the conformational equilibrium of both domains of DnaK towards the open and closed forms, respectively, in a concerted and parallel manner.

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