Current status of diagnosis and treatment of chronic lymphocytic leukemia in China: A national multicenter survey research / 中华血液学杂志

Objective: To understand the current status of diagnosis and treatment of chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL) among hematologists, oncologists, and lymphoma physicians from hospitals of different levels in China. Methods: This multicenter questionnaire survey was conducted from March 2021 to July 2021 and included 1,000 eligible physicians. A combination of face-to-face interviews and online questionnaire surveys was used. A standardized questionnaire regarding the composition of patients treated for CLL/SLL, disease diagnosis and prognosis evaluation, concomitant diseases, organ function evaluation, treatment selection, and Bruton tyrosine kinase (BTK) inhibitor was used. Results: ①The interviewed physicians stated that the proportion of male patients treated for CLL/SLL is higher than that of females, and the age is mainly concentrated in 61-70 years old. ②Most of the interviewed physicians conducted tests, such as bone marrow biopsies and immunohistochemistry, for patient diagnosis, in addition to the blood test. ③Only 13.7% of the interviewed physicians fully grasped the initial treatment indications recommended by the existing guidelines. ④In terms of cognition of high-risk prognostic factors, physicians' knowledge of unmutated immunoglobulin heavy-chain variable and 11q- is far inferior to that of TP53 mutation and complex karyotype, which are two high-risk prognostic factors, and only 17.1% of the interviewed physicians fully mastered CLL International Prognostic Index scoring system. ⑤Among the first-line treatment strategy, BTK inhibitors are used for different types of patients, and physicians have formed a certain understanding that BTK inhibitors should be preferentially used in patients with high-risk factors and elderly patients, but the actual use of BTK inhibitors in different types of patients is not high (31.6%-46.0%). ⑥BTK inhibitors at a reduced dose in actual clinical treatment were used by 69.0% of the physicians, and 66.8% of the physicians had interrupted the BTK inhibitor for >12 days in actual clinical treatment. The use of BTK inhibitors is reduced or interrupted mainly because of adverse reactions, such as atrial fibrillation, severe bone marrow suppression, hemorrhage, and pulmonary infection, as well as patients' payment capacity and effective disease progression control. ⑦Some differences were found in the perceptions and behaviors of hematologists and oncologists regarding the prognostic assessment of CLL/SLL, the choice of treatment options, the clinical use of BTK inhibitors, etc. Conclusion: At present, a gap remains between the diagnosis and treatment of CLL/SLL among Chinese physicians compared with the recommendations in the guidelines regarding the diagnostic criteria, treatment indications, prognosis assessment, accompanying disease assessment, treatment strategy selection, and rational BTK inhibitor use, especially the proportion of dose reduction or BTK inhibitor discontinuation due to high adverse events.

Clonotypic analysis of immunoglobulin heavy chain sequences among 44 patients with Waldenström macroglobulinemia / 中华医学遗传学杂志

OBJECTIVE@#To analyze the correlation between the mutational status of immunoglobulin heavy chain variable (IGHV) gene with the prognosis of patients with Waldenström macroglobulinemia (WM).@*METHODS@#Immunoglobulin heavy chain gene (IGH) clonotypic sequence analysis was carried out to assess the mutational status of IGHV in the blood and/or bone marrow samples from 44 WM patients. The usage characteristics of IGHV-IGHD-IGHJ gene was explored.@*RESULTS@#The most common IGHV subgroup was IGHV3, which was similar to the data from the Institute of Hematology of Chinese Academy of Medical Science. IGHV3-23 (20.45% vs. 15.44%) and IGHV3-74 (11.36% vs. 7.35%) were the main fragments used, which was followed by IGHV4 gene family (15.91% vs. 24.26%). However, no significant correlation was found between the IGHV4 usage and the prognosis of the patients. Should 98% be taken as the cut-off value for the IGHV mutation status, only 5 patients had no IGHV variant, and there was no correlation with the prognosis. Based on the X-tile analysis, 92.6% was re-selected as the cut-off value for the IGHV variant status in such patients. LDH was increased in 26 patients (59.1%) without IGHV variant (P < 0.05), whilst progression-free survival (P < 0.05) and overall survival (P < 0.05) were significantly shorter compared with those with IGHV variants.@*CONCLUSION@#The usage characteristics of IGHV-IGHD-IGHJ in our patients was similar to reported by the Institute of Hematology of Chinese Academy of Medical Science, albeit that no correlation was found between the IGHV4 usage and the prognosis of the patients. Furthermore, 98% may not be appropriate for distinguishing the IGHV variant status in WM patients.

First Case of Transformation of Immunoglobulin Heavy Chain Variable-Mutated Chronic Lymphocytic Leukemia Into Chronic Myeloid Leukemia

No abstract available.

Chronic Lymphocytic Leukemia Prognostic Index: A New Integrated Scoring System to Predict the Time to First Treatment in Chinese Patients with Chronic Lymphocytic Leukemia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The established clinical staging systems (Rai/Binet) of chronic lymphocytic leukemia (CLL) cannot accurately predict the appropriate treatment of patients in the earlier stages. In the past two decades, several prognostic factors have been identified to predict the outcome of patients with CLL, but only a few studies investigated more markers together. To predict the time to first treatment (TTFT) in patients of early stages, we evaluated the prognostic role of conventional markers as well as cytogenetic abnormalities and combined them together in a new prognostic scoring system, the CLL prognostic index (CLL-PI).</p><p><b>METHODS</b>Taking advantage of a population of 406 untreated Chinese patients with CLL at early and advanced stage of disease, we identified the strongest prognostic markers of TTFT and, subsequently, in a cohort of 173 patients who had complete data for all 3 variables, we integrated the data of traditional staging system, cytogenetic aberrations, and mutational status of immunoglobulin heavy chain variable region (IGHV) in CLL-PI. The median follow-up time was 45 months and the end point was TTFT.</p><p><b>RESULTS</b>The median TTFT was 38 months and the 5-year overall survival was 80%. According to univariate analysis, patients of advanced Rai stages (P < 0.001) or with 11q- (P = 0.002), 17p- (P < 0.001), unmutated IGHV (P < 0.001), negative 13q- (P = 0.007) and elevated lactate dehydrogenase levels (P = 0.001) tended to have a significantly shorter TTFT. And subsequently, based on multivariate Cox regression analysis, three independent factors for TTFT were identified: advanced clinical stage (P = 0.002), 17p- (P = 0.050) and unmutated IGHV (P = 0.049). Applying weighted grading of these independent factors, a CLL-PI was constructed based on regression parameters, which could categorize four different risk groups (low risk [score 0], intermediate low [score 1], intermediate high [score 2] and high risk [score 3-6]) with significantly different TTFT (median TTFT of not reached (NR), 65.0 months, 36.0 months and 19.0 months, respectively, P < 0.001).</p><p><b>CONCLUSIONS</b>This study developed a weighted, integrated CLL-PI prognostic system of CLL patients which combines the critical genetic prognostic markers with traditional clinical stage. This novel modified PI system could be used to discriminate among groups and may help predict the TTFT and prognosis of patients with CLL.</p>

Detection of Immunoglobulin Heavy Chain Gene Clonality by Next-Generation Sequencing for Minimal Residual Disease Monitoring in B-Lymphoblastic Leukemia

Minimal residual disease (MRD) following B-lymphoblastic leukemia (B-ALL) treatment has gained prognostic importance. Clonal immunoglobulin heavy chain (IGH) gene rearrangement is a useful follow-up marker in B-ALL owing to its high positivity rate. We evaluated the performance and clinical applicability of a next-generation sequencing (NGS) assay for IGH rearrangement in B-ALL MRD monitoring. IGH rearrangement was tested by using fluorescence PCR-fragment analysis and the NGS assay in eight B-ALL patients. The NGS assay was run on two platforms: the Ion Torrent PGM (Thermo Fisher Scientific, USA) (18 samples from 1st to 7th patients) and the MiSeq system (Illumina, USA) (four samples from 8th patient). All initial diagnostic samples and four follow-up samples were positive for clonal IGH rearrangement with fluorescence PCR-fragment analysis and the NGS assay, and six follow-up samples were positive only with NGS. In one case with BCR-ABL1 translocation, BCR-ABL1 quantitative PCR was negative but the NGS IGH assay was positive just prior to full-blown relapse, suggesting the high sensitivity and clinical utility of the NGS assay. The NGS assay is proposed for MRD monitoring in B-ALL Additional studies are needed to confirm the clinical implications of cases showing positive results only in NGS.

Research of Human-mouse Chimeric Antibodies Against Ebola Virus Nucleoprotein / 病毒学报

The Ebola virus is highly infectious and can result in death in ≤ 90% of infected subjects. Detection of the Ebola virus and diagnosis of infection are extremely important for epidemic control. Presently, Chinese laboratories detect the nucleic acids of the Ebola virus by real-time reverse transcription-polymerase chain reaction (RT-PCR). However, such detection takes a relatively long time and necessitates skilled personnel and expensive equipment. Enzyme-linked immunosorbent assay (ELISA) of serum is simple, easy to operate, and can be used to ascertain if a patient is infected with the Ebola virus as well as the degree of infection. Hence, ELISA can be used in epidemiological investigations and is a strong complement to detection of nucleic acids. Cases of Ebola hemorrhagic fever have not been documented in China, so quality-control material for positive serology is needed. Construction and expression of human-mouse chimeric antibodies against the nucleoprotein of the Ebola virus was carried out. Genes encoding variable heavy (VH) and variable light (VL) chains were extracted and amplified from murine hybridoma cells. Genes encoding the VH and VL chains of monoclonal antibodies were amplified by RT-PCR. According to sequence analyses, a primer was designed to amplify functional sequences relative to VH and VL chain. The eukaryotic expression vector HL51-14 carrying some human antibody heavy chain- and light chain-constant regions was used. IgG antibodies were obtained by transient transfection of 293T cells. Subsequently, immunological detection and immunological identification were identified by ELISA, immunofluorescence assay, and western blotting. These results showed that we constructed and purified two human- mouse chimeric antibodies.

Nanobody: a Novel Molecular Imaging Tool / 中国医疗器械杂志

Nanobodies are derived from the variable domain of the heavy-chain antibodies (HCAbs) that occur naturally in the serum of camels. Using nanobody-based probes, several imaging techniques such as radionuclide-based, optical and ultrasound have been employed for visualization of target expression in various disease models. Combined with application and clinical data of nanobody in molecular imaging in recent years, this paper introduces its application in the diagnosis of diseases and the future development as a novel molecular imaging tool.

Isochromosome 1q in Childhood Burkitt Lymphoma: The First Reported Case in Korea

No abstract available.

Clinical features and outcomes of systemic amyloidosis with gastrointestinal involvement: a single-center experience

BACKGROUND/AIMS: The gastrointestinal (GI) tract often becomes involved in patients with systemic amyloidosis. As few GI amyloidosis data have been reported, we describe the clinical features and outcomes of patients with pathologically proven GI amyloidosis. METHODS: We identified 155 patients diagnosed with systemic amyloidosis between April 1995 and April 2013. Twenty-four patients (15.5%) were diagnosed with GI amyloidosis using associated symptoms, and the diagnoses were confirmed by direct biopsy. RESULTS: Among the 24 patients, 20 (83.3%) had amyloidosis light chain (AL), three (12.5%) had amyloid A, and one (4.2%) had transthyretin-related type amyloidosis. Their median age was 57 years (range, 37 to 72), and 10 patients were female (41.7%). The most common symptoms of GI amyloidosis were diarrhea (11 patients, 45.8%), followed by anorexia (nine patients, 37.5%), weight loss, and nausea and/or vomiting (seven patients, 29.2%). The histologically confirmed GI tract site in AL amyloidosis was the stomach in 11 patients (55.0%), the colon in nine (45.0%), the rectum in seven (35.0%), and the small bowel in one (5.0%). Patients with GI involvement had a greater frequency of organ involvement (p = 0.014). Median overall survival (OS) in patients with GI involvement was shorter (7.95 months; range, 0.3 to 40.54) than in those without GI involvement (15.84 months; range, 0.0 to 114.53; p = 0.069) in a univariate analysis. A multivariate analysis of prognostic factors for AL amyloidosis revealed that GI involvement was not a significant predictor of OS (p = 0.447). CONCLUSIONS: The prognosis of patients with AL amyloidosis and GI involvement was poorer than those without GI involvement, and they presented with more organ involvement and more advanced disease than those without organ involvement.

Submicroscopic Deletions of Immunoglobulin Heavy Chain Gene (IGH) in Precursor B Lymphoblastic Leukemia with IGH Rearrangements

Translocations leading to fusions between the immunoglobulin heavy chain gene (IGH) and various partner genes have been reported in B-cell precursor acute lymphoblastic leukemia (B-ALL). However, submicroscopic deletions within IGH in B-ALL have not been rigorously assessed. In this study, we investigated characteristics of IGH submicroscopic deletions, by FISH, in B-ALL with IGH rearrangements. FISH was performed by using commercially available IGH dual-color break-apart rearrangement probes (Abbott/Vysis, Downers Grove, IL, USA; Kreatech, Amsterdam, Netherlands). The study group included seven B-ALL patients with IGH rearrangements, observed by FISH. Among them, two exhibited deletion of the 5' variable region of IGH by FISH. The B-ALL in these two patients included two kinds of abnormal cells; one had an IGH rearrangement without any IGH submicroscopic deletion, while the other had an IGH submicroscopic deletion, which showed that one normal fusion signal and one 3' IGH signal were detected. Thus, submicroscopic deletion of the IGH 5' variable region may have occurred in either the native or rearranged chromosome 14. These findings indicate that B-ALL with IGH rearrangements may be accompanied by submicroscopic deletions of the IGH 5' variable region, which can be detected by FISH. The clinical significance of such deletions is unclear, but the loss of part of the IGH gene in B-ALL warrants further study.

Effect of immunoglobulin heavy/light chain detection on the minimal residual disease monitoring in IgG multiple myeloma patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To evaluate the specificity and sensitivity of immunoglobulin heavy/light chain (HLC) and serum free light chain (FLC) level in minimal residual disease monitoring of IgG type multiple myeloma (MM) patients during complete remission (CR).</p><p><b>METHODS</b>Immunoglobulin HLC was assessed in 20 IgG myeloma patients by immune turbidimetry using SPAplus Analyzer. The serum level of HLC and FLC was detected at same time. Combine with those obtained by serum protein electrophoresis (SPE) and immune fixation electrophoresis (IFE), the specificity and sensitivity of HLC in detection of serum immunoglobulin were analyzed. Combined with the clinical efficacy, kappa/lambda ratios of HLC (rHLC) and FLC (rFLC) were compared between the patients and normal controls.</p><p><b>RESULTS</b>Among 20 patients, there were 10 male and 10 female, the median age was 56 years (35-70). There were 6 patients with abnormal rHLC but normal rFLC; 3 patients with abnormal rFLC but normal HLC; and 11 patients with both normal rHLC and rFLC. During the mean follow-up time of 18 months, 4 of the6 patients with abnormal rHLC accepted intervention therapies, 1 case relapsed in 9 months,the other 2 untreated patients relapsed in 3 months. Among the 3 cases with abnormal rFLC, 2 patients are still in remission after intervention therapies,the other untreated patient relapsed in 1.5 months. Among the 11 untreated patients with both normal rHLC and rFLC, 3 relapsed with the disease free survival time of 3.5 months, 5.0 months and 5.5 months respectively.</p><p><b>CONCLUSION</b>The combined detection of HLC and FLC is helpful to assess the curative efficacy and the accuracy of minimal residual disease monitoring, and more effectively evaluate the prognosis of MM patients. Abnormal rHLC and rFLC are correlated with poor prognosis, while early intervention therapies can help to improve disease free survival.</p>

Primary cutaneous diffuse large B-cell lymphoma, leg type: a study of clinicopathology, immunophenotype and gene rearrangement / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype and gene rearrangement of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL).</p><p><b>METHODS</b>Seven cases of PCLBCL were enrolled into the study. Clinicopathologic analysis, immunohistochemical staining and gene rearrangement for IgH and Igκ were undertaken in the study.</p><p><b>RESULTS</b>All the seven cases were male, and the median age was 72 years. Patients usually presented with multiple purple tumors, nodules, papules and infiltrative plaques. Two patients had a history of leg injury before onset, and one had mosquito bites. Histologically, the tumor involved the dermis and subcutis with dense and diffuse infiltrative pattern composing of centroblasts and/or immunoblasts. Immunohistochemical staining showed that seven cases (7/7) expressed CD20, six (6/6) expressed bcl-2, four (4/4) expressed MUM-1, four (4/5) expressed CD79a, four (4/5) expressed PAX-5 and four (4/6) expressed bcl-6, respectively. All cases did not express CD3ε, CD45RO, CD10 and CD30. IgH gene rearranged bands were detected in three (3/6) cases and Igκ was detected in one (1/5) case. Six of the seven cases died and the remaining patient, who was 44-year-old, was alive after 22 months of follow-up.</p><p><b>CONCLUSIONS</b>PCLBCL is rare, predominantly affects elderly male patients. PCLBCL has poor prognosis and high mortality, but younger patients seem to have better prognosis. Some cases had a history of trauma or mosquito bites. The relationship between the history and the onset of PCLBCL needs further evaluation.</p>

Isolation and characterization of recombinant variable domain of heavy chain anti-idiotypic antibodies specific to aflatoxin B1 / 生物医学与环境科学（英文）

Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain (VHH). The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F(ab')2 fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic (anti-Id) responses. Antigen-specific elution method was used for panning private anti-Id VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay (ELISA). Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.

Progress in nanobody and its application in diagnosis / 生物工程学报

Nanobodies are derived from the variable domain of the heavy-chain antibodies (HCAbs) that occur naturally in the serum of Camelidae. They are the smallest antibody fragments capable to bind antigens. With the characteristics of their increased solubility, increased domain stabilities, nanomolar affinities, easy crossing the blood-brain barrier, easy generation, engineering, optimization and tailoring, easy humanization, nanobodies have extensive application prospects in diagnosis and detection. Although nanobody has demonstrated tremendous success, a number of practical challenges limit its broader applications in disease diagnosis and detection, including construction of a phage library and selection of nanobody fragments with high affinity and immunogold labeling technique. Here, we review several recent findings on the use of nanobodies in molecular diagnostics and suggest some practical strategies in resolving the current challenges in this attractive research area, particularly to optimize the affinity, solubility, humanization of nanobodies.

Intravascular Cytotoxic T-Cell Lymphoma in a Young Immunocompetent Woman

Intravascular lymphoma (IVL) is a rare disorder characterized by the presence of large neoplastic lymphoid cells restricted to the lumens of small vessels with a predilection for the skin and the central nervous system. While the vast majority of cases involving IVL are of B-cell lineage, the disease rarely affects the T-cell, the histiocytes, and the natural killer cells. We report a case of intravascular T-cell lymphoma (IVTL) associated with Epstein-Barr virus (EBV). A 23-year-old healthy woman presented with tender indurated erythematous patches with overlying telangiectasia on her right breast, abdomen, both the upper and the lower extremities and the back for 3 months. The pathology revealed an infiltration of dermal and subcutaneous vessels by large and atypical lymphoid cells with immunohistochemical features of the T-cell lineage with a cytotoxic phenotype (CD3+, CD8+, granzyme B+, TIA-1+, CD4-, CD5-, CD20-, CD56-). Interestingly, the DNA extracted from the skin biopsies demonstrated evidence of a monoclonal immunoglobulin heavy chain gene rearrangement, but no T-cell receptor gene rearrangement was found. In situ hybridization study for EBV-encoded RNA was positive. She was diagnosed with an EBV-associated IVTL. The patient's skin lesions were refractory to the combination of chemotherapy and autologous stem cell transplant, and she expired. The findings in the present case may highlight the unique clinicopathologic aspects of EBV-associated cytotoxic IVTL that occurred in a young, immunocompetent woman.

Nodular lymphoid hyperplasia of the stomach in a patient with multiple submucosal tumors

Nodular lymphoid hyperplasia of the stomach is a rare lymphoproliferative disorder. Here, we report a 38-year-old man who presented with multiple submucosal tumors of the stomach. Histologically, the lesions were characterized by multiple discrete submucosal nodules of lymphoid cells. The infiltrates between the lymphoid follicles were composed mainly of medium-sized lymphoid cells with abundant clear cytoplasm, as well as a few large cells with vesicular nuclei. The gastric mucosa exhibited multifocal lymphoid aggregates and some of the epithelial cells were infiltrated by small lymphocytes mimicking lymphoepithelial lesions. Histopathology was consistent with mucosa-associated lymphoid tissue lymphoma. However, the infiltrating lymphoid cells were positive for CD2, CD3, CD5, and CD7. In addition, polymerase chain reaction analysis of the immunoglobulin heavy chain and T-cell receptor gene rearrangements demonstrated polyclonality. This case was diagnosed as reactive lymphoid hyperplasia of the stomach.

Construction of full-length human bladder cancer-specific antibody libraries based on mammalian display technology / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct full-length human bladder cancer-specific antibody libraries for efficient display of full-length antibodies on the surface of mammalian cells.</p><p><b>METHODS</b>The total RNA was isolated from peripheral blood mononuclear cells from patients with bladder cancer. The repertoires of IgG1 heavy chain variable region (VH) and Kappa light chain were amplified by RT-PCR using specific primers. The antibody genes were inserted into the vector pDGB-HC-TM to construct the bladder-cancer-specific antibody libraries of heavy chains and light chains. Ten clones from each library were randomly picked for gene sequencing and transient transfection into FCHO cells to analyze antibody display on mammalian cell surface by flow cytometry after staining with corresponding fluorescent labeled antibodies.</p><p><b>RESULTS</b>The libraries of bladder-cancer-specific antibody heavy chain (IgG1) and light chain (LCk) were successfully constructed. Seven out of the 10 clones randomly selected from the heavy chain library and 9 out of the 10 clones from the light chain library showed correct open reading frame, coding for 7 unique VH and 9 unique LCk. The combinatory library size reached 3.32×10(11).</p><p><b>CONCLUSION</b>We have successfully constructed a full-length human bladder-cancer-specific antibody library with a combinatory diversity of 3.32×10(11) based on mammalian display technology, which can be used for screening monoclonal antibodies against bladder-cancer-associated antigens.</p>

Construction of dengue virus-specific full-length fully human antibody libraries by mammalian display technology / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct dengue virus-specific full-length fully human antibody libraries using mammalian cell surface display technique.</p><p><b>METHODS</b>Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) from convalescent patients with dengue fever. The reservoirs of the light chain and heavy chain variable regions (LCκ and VH) of the antibody genes were amplified by RT-PCR and inserted into the vector pDGB-HC-TM separately to construct the light chain and heavy chain libraries. The library DNAs were transfected into CHO cells and the expression of full-length fully human antibodies on the surface of CHO cells was analyzed by flow cytometry.</p><p><b>RESULTS</b>Using 1.2 µg of the total RNA isolated from the PBMCs as the template, the LCκ and VH were amplified and the full-length fully human antibody mammalian display libraries were constructed. The kappa light chain gene library had a size of 1.45×10(4) and the heavy chain gene library had a size of 1.8×10(5). Sequence analysis showed that 8 out of the 10 light chain clones and 7 out of the 10 heavy chain clones randomly picked up from the constructed libraries contained correct open reading frames. FACS analysis demonstrated that all the 15 clones with correct open reading frames expressed full-length antibodies, which could be detected on CHO cell surfaces. After co-transfection of the heavy chain and light chain gene libraries into CHO cells, the expression of full-length antibodies on CHO cell surfaces could be detected by FACS analysis with an expressible diversity of the antibody library reaching 1.46×10(9) [(1.45×10(4)×80%)×(1.8×10(5)×70%)].</p><p><b>CONCLUSION</b>Using 1.2 µg of total RNA as template, the LCκ and VH full-length fully human antibody libraries against dengue virus have been successfully constructed with an expressible diversity of 10(9).</p>

Gene construction and screening of humanized single chain antibody library against VSTM1-v2 cytokine / 药学学报

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.

Optimizing the host bacteria to make a large naive phage antibody library in the recombination system / 药学学报

To prepare large naive phage antibody library, the host bacteria with high transformation efficiency is used in the Cre-LoxP recombination system. The variable regions of immunoglobulin light and heavy genes were amplified from lymphocytes collected from adult peripheral blood and newborn cord blood. The genes were spliced to form the single-chain variable fragments (scFv) by overlap PCR, cloned into pDAN5a vector and then transformed into XL2-blue MRF' with the Hte gene. Compared with XL1-blue strain, the size of the primary library was increased by 3.9 times. The primary library infected Cre recombinase-expressing bacteria, and the genes between phagemids created many new VH/VL combinations. The library was calculated to have a diversity of 1.7 x 10(11) and validated by the selection of antibodies against six different protein antigens. This library provides the basis for further selection of antibody-based drugs. It is the first time to report that XL2-blue MRF' can be used to improve the diversity of the library in the recombination system.