OBJECTIVES: To investigate the diversity of peripheral blood T cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) based on immune repertoire sequencing in neonates with sepsis and the possible pathogenesis of neonatal sepsis. METHODS: A total of 12 neonates with sepsis were enrolled as the case group, and 9 healthy full-term infants, matched for gestational age, birth weight, and age, were enrolled as the control group. Omega nucleic acid purification kit (SQ blood DNA Kit II) was used to extract DNA from peripheral blood samples, TCR β chain CDR3 was amplified by multiplex PCR, and then high-throughput sequencing was performed for the products to analyze the diversity of TCR β chain CDR3 and the difference in expression. RESULTS: The length and type of TCR β chain CDR3 were similar between the case and control groups, and Gaussian distribution was observed in both groups. With D50 and Shannon-Wiener index as the evaluation indices for diversity, the case group had a significantly lower diversity of TCR β chain CDR3 than the control group ( CONCLUSIONS There is a significant change in the diversity of TCR β chain CDR3 in the peripheral blood of neonates with sepsis, suggesting that it might be associated with the immune pathogenesis of neonatal sepsis.
Complementarity Determining Regions/genetics* ; High-Throughput Nucleotide Sequencing ; Humans ; Multiplex Polymerase Chain Reaction ; Neonatal Sepsis ; Receptors, Antigen, T-Cell, alpha-beta/genetics*

Phage display technology provides a powerful tool to screen a library for a binding molecule via an enrichment process. It has been adopted as a critical technology in the development of therapeutic antibodies. However, a major drawback of phage display technology is that because the degree of the enrichment cannot be controlled during the bio-panning process, it frequently results in a limited number of clones. In this study, we applied next-generation sequencing (NGS) to screen clones from a library and determine whether a greater number of clones can be identified using NGS than using conventional methods. Three chicken immune single-chain variable fragment (scFv) libraries were subjected to bio-panning on prostate-specific antigen (PSA). Phagemid DNA prepared from the original libraries as well as from the Escherichia coli pool after each round of bio-panning was analyzed using NGS, and the heavy chain complementarity-determining region 3 (HCDR3) sequences of the scFv clones were determined. Subsequently, through two-step linker PCR and cloning, the entire scFv gene was retrieved and analyzed for its reactivity to PSA in a phage enzyme immunoassay. After four rounds of bio-panning, the conventional colony screening method was performed for comparison. The scFv clones retrieved from NGS analysis included all clones identified by the conventional colony screening method as well as many additional clones. The enrichment of the HCDR3 sequence throughout the bio-panning process was a positive predictive factor for the selection of PSA-reactive scFv clones.
Antibodies ; Bacteriophages ; Chickens ; Clone Cells* ; Cloning, Organism ; Complementarity Determining Regions ; DNA ; Escherichia coli ; Immunoenzyme Techniques ; Mass Screening ; Methods ; Polymerase Chain Reaction ; Prostate-Specific Antigen ; Single-Chain Antibodies

BACKGROUND: This study characterized clonal IG heavy V-D-J (IGH) gene rearrangements in South Indian patients with precursor B-cell acute lymphoblastic leukemia (precursor B-ALL) and identified age-related predominance in VDJ rearrangements. METHODS: IGH rearrangements were studied in 50 precursor B-ALL cases (common ALL=37, pre-B ALL=10, pro-B ALL=3) by polymerase chain reaction (PCR) heteroduplex analysis. Twenty randomly selected clonal IGH rearrangement sequences were analyzed using the IMGT/V-QUEST tool. RESULTS: Clonal IGH rearrangements were detected in 41 (82%) precursor B-ALL cases. Among the IGHV1-IGHV7 subgroups, IGHV3 was used in 25 (50%) cases. Among the IGHD1-IGHD7 genes, IGHD2 and IGHD3 were used in 8 (40%) and 5 (25%) clones, respectively. Among the IGHJ1-IGHJ6 genes, IGHJ6 and IGHJ4 were used in 9 (45%) and 6 (30%) clones, respectively. In 6 out of 20 (30%) IGH rearranged sequences, CDR3 was in frame whereas 14 (70%) had rearranged sequences and CDR3 was out of frame. A somatic mutation in Vmut/Dmut/Jmut was detected in 14 of 20 IGH sequences. On average, Vmut/Dmut/Jmut were detected in 0.1 nt, 1.1 nt, and 0.2 nt, respectively. CONCLUSION: The IGHV3 gene was frequently used whereas lower frequencies of IGHV5 and IGHV6 and a higher frequency of IGHV4 were detected in children compared with young adults. The IGHD2 and IGHD3 genes were over-represented, and the IGHJ6 gene was predominantly used in precursor-B-ALL. However, the IGH gene rearrangements in precursor-B-ALL did not show any significant age-associated genotype pattern attributed to our population.
Child ; Clone Cells ; Complementarity Determining Regions* ; Gene Rearrangement* ; Genotype ; Heteroduplex Analysis ; Humans ; Immunoglobulins* ; Polymerase Chain Reaction ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Precursor Cells, B-Lymphoid* ; Young Adult

The C-terminal domain of RNA polymerase II is an unusual series of repeated residues appended to the C-terminus of the largest subunit and serves as a flexible binding scaffold for numerous nuclear factors. The binding of these factors is determined by the phosphorylation patterns on the repeats in the domain. In this study, we generated a synthetic antibody library by replacing the third heavy chain complementarity-determining region of an anti-HER2 (human epidermal growth factor receptor 2) antibody (trastuzumab) with artificial sequences of 7–18 amino-acid residues. From this library, antibodies were selected that were specific to serine phosphopeptides that represent typical phosphorylation patterns on the functional unit (YSPTSPS)₂ of the RNA polymerase II C-terminal domain (CTD). Antibody clones pCTD-1stS2 and pCTD-2ndS2 showed specificity for peptides with phosphoserine at the second residues of the first or second heptamer repeat, respectively. Additional clones specifically reacted to peptides with phosphoserine at the fifth serine of the first repeat (pCTD-1stS5), the seventh residue of the first repeat and fifth residue of the second repeat (pCTD-S7S5) or the seventh residue of either the first or second repeat (pCTD-S7). All of these antibody clones successfully reacted to RNA polymerase II in immunoblot analysis. Interestingly, pCTD-2ndS2 precipitated predominately RNA polymerase II from the exonic regions of genes in genome-wide chromatin immunoprecipitation sequencing analysis, which suggests that the phosphoserine at the second residue of the second repeat of the functional unit (YSPTSPS)2 is a mediator of exon definition.
Antibodies ; Chromatin Immunoprecipitation ; Clone Cells ; Complementarity Determining Regions ; DNA-Directed RNA Polymerases* ; Exons* ; Peptides ; Phosphopeptides ; Phosphorylation* ; Phosphoserine ; Receptor, Epidermal Growth Factor ; RNA Polymerase II* ; RNA* ; Sensitivity and Specificity ; Serine

OBJECTIVETo observe anti-cancer effects of Jianpi Jiedu Recipe (JJR) on liver cancer (LC) rats with Pi deficiency syndrome (PDS) and its relation with the third complementary-determining region gene spectratyping of TCRVβ-chain (TCRVβCDR3).

METHODSRats were divided into 8 groups according to random digit table, i.e., the blank control group (normal), the PDS group, the LC model group, the LC-PDS group, high, middle, and low dose JJR groups (75.00, 37.50, 18.75 g/kg, respectively by gastrogavage, once per day), the thymus pentapeptide group (5 mg/kg, intramuscular injection, twice per week), 8 in each group. Rats in the normal group were administered with physiological saline by gastrogavage once per day. PDS rat model was prepared by bitter-cold purgation. LC model was prepared by orthotopic transplantation method. Twenty gene subfamilies of TCRβCDR3 in the thymus, liver, and LC tissues were detected by Gene Scan.

RESULTSHigh and middle dose JJR could postpone the growth of LC volume (P < 0.05), with equivalent liver index and thymus index to those of the normal group (P > 0.05). In thymus and liver tissue of the normal group, the number of clones (20 and 19), gene fragment number (220 and 113), Quasi-Gaussian distribution ratio of TCRVβCDR3 gene repertoire (100.0% and 42.1%), and fragment fluorescence peak area (6,539 ± 2,325 and 1,238 ± 439) were at the highest level among the 8 groups. TCRVβCDR3 expressions in thymus and liver tissue of high and middle dose JJR groups were approximate to those of the normal group. They were in the middle of the thymus pentapeptide group, the PDS group, the LC model group, and poorest in the LC-PDS group. TCRVβCDR3 in liver tissue expressed the best in the thymus pentapeptide group.

CONCLUSIONJJR might inhibit the growth of LC cells, and its mechanism might be related to enhancing TCRVβCDR3 spectratype expression.

Animals ; Complementarity Determining Regions ; genetics ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; Genes, T-Cell Receptor beta ; Liver Neoplasms ; drug therapy ; genetics ; Random Allocation ; Rats

To explore the association between T-cell receptor beta variable (TCR BV) complementarity determining region 3 (CDR3) spectratyping and CMV activation in the recipients of allogeneic hematopoietic stem cell transplantation (HSCT).Fluorescence quantitative PCR melting curve analysis was used to sequence 24 TCR BV families in 7 HSCT recipients and 3 healthy controls. CMV-pp65 antigenemia was measured by immunohistochemical staining. Plasma IgM specific for CMV was identified using ELISA. Relationship between TCR BV families and CMV activation was statistically analyzed.Twenty-four TCR BV families were expressed in 3 healthy controls, while TCR BV CDR3 sequencing results in 7 recipients turned out to be BV9, BV11, BV17, BV20 and so on. Amino acid sequence features were as follows:TCR BV9 contained "QVRGGTDTQ", TCR BV11 contained "VATDEQ" and "LGDEQ", TCR BV17 contained "IGQGNTEA", and TCR BV20 contained "VGLAANEQ". Five recipients suffered from pp65 antigenemia in 3 month after transplantation, and pp65-positive cells ranged from 2 to 15 per 5×10white blood cells. Three recipients were CMV-IgM positive. No significant differences were found in TCR BV families between pp65-positive recipients and pp65-negative recipients (all>0.05). But there was statistically significant difference in frequency of TCR BV11 between CMV-IgM negative recipients and CMV-IgM positive recipients (<0.05).T cell immune response was characterized by special TCR BV CDR3 spectratyping in HSCT recipients, and TCR BV11 expression may be associated with CMV activation.
Amino Acid Sequence ; Complementarity Determining Regions ; genetics ; immunology ; Cytomegalovirus ; genetics ; immunology ; Cytomegalovirus Infections ; genetics ; Genotype ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Lymphocyte Activation ; genetics ; Phosphoproteins ; Polymerase Chain Reaction ; Polymorphism, Genetic ; immunology ; Receptors, Antigen, T-Cell, alpha-beta ; genetics ; immunology ; Spleen ; T-Lymphocytes ; immunology ; virology ; Viral Matrix Proteins

The characterization of the human T-cell receptor (TCR) repertoire has made remarkable progress, with most of the work focusing on the TCRβ chains. Here, we analyzed the diversity and complexity of both the TCRα and TCRβ repertoires of three healthy donors. We found that the diversity of the TCRα repertoire is higher than that of the TCRβ repertoire, whereas the usages of the V and J genes tended to be preferential with similar TRAV and TRAJ patterns in all three donors. The V-J pairings, like the V and J gene usages, were slightly preferential. We also found that the TRDV1 gene rearranges with the majority of TRAJ genes, suggesting that TRDV1 is a shared TRAV/DV gene (TRAV42/DV1). Moreover, we uncovered the presence of tandem TRBD (TRB D gene) usage in ~2% of the productive human TCRβ CDR3 sequences.
Complementarity Determining Regions ; genetics ; DNA Primers ; chemistry ; genetics ; Female ; Gene Rearrangement, beta-Chain T-Cell Antigen Receptor ; genetics ; Gene Rearrangement, delta-Chain T-Cell Antigen Receptor ; genetics ; Genes, T-Cell Receptor beta ; genetics ; Genetic Variation ; High-Throughput Nucleotide Sequencing ; Humans ; Immunoglobulin Joining Region ; genetics ; Immunoglobulin Variable Region ; genetics ; Male ; Receptors, Antigen, T-Cell, alpha-beta ; genetics

To rapidly select potent anti-VSTM1-v2 scFv (single-chain antibody fragment) by construction and screening of a humanized scFv library in which a murine VH-CDR3 library was grafted onto a human scFv framework. A murine VH-CDR3 library was amplified from anti-VSTM1-v2 murine cDNA and grafted on human scFv (VH3-VK1) framework. Anti-VSTM1-v2 scFv templates were selected and enriched through ribosome display, TA-cloned into expression vector, and transformed into BL21 (DE3) for soluble expression of target scFv. A total of 1000 clones were randomly picked. Positive ones were first identified using colony PCR, indirect ELISA, Western blotting and then verified with sequencing and dose response ELISA. At last an anti-VSTM1-v2 humanized scFv with good binding affinity (EC50 = 21.35 nmol x L(-1)) was selected from the humanized library of 10(12) members generated in this study. This scFv antibody might have potential applications. This study provides a new approach for rapid screening of humanized antibodies.
Animals ; Complementarity Determining Regions ; genetics ; immunology ; Cytokines ; immunology ; Humans ; Immunoglobulin Fragments ; genetics ; immunology ; Immunoglobulin Heavy Chains ; genetics ; immunology ; Mice ; Peptide Library ; Protein Binding ; Receptors, Immunologic ; immunology ; Single-Chain Antibodies ; genetics ; immunology ; isolation & purification

Since the publication of a high-throughput DNA sequencing technology based on PCR reaction was carried out in oil emulsions in 2005, high-throughput DNA sequencing platforms have been evolved to a robust technology in sequencing genomes and diverse DNA libraries. Antibody libraries with vast numbers of members currently serve as a foundation of discovering novel antibody drugs, and high-throughput DNA sequencing technology makes it possible to rapidly identify functional antibody variants with desired properties. Herein we present a review of current applications of high-throughput DNA sequencing technology in the analysis of antibody library diversity, sequencing of CDR3 regions, identification of potent antibodies based on sequence frequency, discovery of functional genes, and combination with various display technologies, so as to provide an alternative approach of discovery and development of antibody drugs.
Animals ; Antibody Diversity ; genetics ; Base Sequence ; Complementarity Determining Regions ; chemistry ; genetics ; DNA ; genetics ; DNA, Complementary ; genetics ; Drug Discovery ; methods ; Gene Library ; High-Throughput Nucleotide Sequencing ; methods ; Humans ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; methods

OBJECTIVETo analyze the drift of T cell receptor (TCR) Vα and Vβ gene family CDR3 spectratype in response to ovarian carcinoma cells mediated by an anti-human ovarian carcinoma/CD3 bispecific single-chain antibody (BHL-1), and explore the mechanism of the bispecific single-chain antibody-mediated T cell immune response.

METHODSImmunoscopic spectratyping technique was used to analyze the TCR repertoire diversity (CDR3 spectratype distribution) of the T cells from 6 healthy donors before and after stimulation of the cells with human ovarian carcinoma in the presence of BHL-1. The predominant usage of TCR α and Vβ chain CDR3 was analyzed after the stimulation, and sequence analysis was performed for the CDR3 region of the monoclonal T cells.

RESULTSThe spectratypes of Vα and Vβ gene family TCR CDR3 region showed a Gaussian distribution before stimulation of the T cells from the 6 donors. After stimulation of the T cells, CDR3 spectratype drift occurred in the T cells, and some TCR Vα and Vβ families showed an anomalous and oligoclonal expansion. Different CDR3 sequences of the Vα and Vβ gene family TCR were found in the monoclonal T cells stimulated with BHL-1.

CONCLUSIONCDR3 spectratype drift occurs in TCR α and Vβ chains of T cells after stimulation with human ovarian carcinoma cells and BHL-1, indicating that the predominant usage of TCR Vα and Vβ families is associated with the specific T cell immune response mediated by BHL-1.

Antibodies, Bispecific ; immunology ; Cell Line ; Cell Line, Tumor ; Complementarity Determining Regions ; immunology ; Female ; Humans ; Monocytes ; immunology ; Ovarian Neoplasms ; immunology ; Receptors, Antigen, T-Cell, alpha-beta ; immunology ; Single-Chain Antibodies ; immunology