Effect of static pressure on ultrasonic liquid phase exfoliation of few-layer graphene

Ultrasonic Liquid Phase Exfoliation (LPE) has gathered attention from both scientific and industrial communities for its accessibility and cost-effectiveness in producing graphene. However, this technique has faced challenges such as low yield and long production time. In this study, we developed a cyclic ultrasonication system to exfoliate expanded graphite (EG) by applying static pressure to a flow chamber to address these challenges. Using deionized water (DIW) as solvent and polyvinylpyrrolidone (PVP) as dispersion, we obtained graphene slurries with an average lateral size of 7 μm and averaged number of layers of 3.5 layers, after 40 min of ultrasonication. After centrifugation, the yield of single and bilayer graphene was approximately 16 %. The findings showed that regulating hydrostatic pressure can effectively affect the lateral size and number of layers of few-layer graphene. The proposed method is of good potential for scaled-up production of few-layer graphene.

[Multi-center real world study of the efficacy and safety of albumin-bound paclitaxel in the treatment of advanced breast cancer]

Objective: To observe the efficacy and safety of albumin-bound paclitaxel in the treatment of metastatic breast cancer. Methods: Multi-center data of patients who accepted single-drug albumin-bound paclitaxel or combination regimens from 2013 to 2019 were collected and the efficacy and safety were evaluated. Kaplan-Meier method was used for survival analysis, while Log-rank test was used to compare the survival rates. Results: A total of 203 advanced breast cancer cases were enrolled. The median progression-free survival time (PFS) lasted for 4 months, the median overall survival(OS)was 14 months, objective response rate (ORR) was 36.0% while the disease control rate (DCR) was 81.3%. The ORRs of Luminal, human epidermal growth factor receptor 2 (HER2) overexpression and triple-negative breast cancer patients underwent albumin-bound paclitaxel treatment were 37.3%, 45.5% and 31.0%, respectively, the DCRs were 85.5%, 68.2% and 78.9%, respectively. The OS of patients with relapse or metastasis who accepted less than two and more than two chemotherapy regimens were 22 months and 11 months (P<0.000 1), the ORRs were 44.9% vs 30.4%, DCRs were 87.2% vs 77.6% (P=0.018). The ORR and DCR of patients who accepted traditional paclitaxel treatment before the albumin-bound paclitaxel treatment were 35.8% and 82.1%, respectively. The common adverse reaction of these patients was numbness of limbs, which incidence rate was 64.5% (131/203), and 61.1% (124/203) were degree 1 to 2. Other adverse reactions including decreased white blood cells, which incidence rate was 56.1% (114/203); nausea and vomit, which incidence rate was 36.9% (75/203); anemia, which incidence rate was 21.2% (43/203); decreased platelet, which incidence rate was 18.7% (38/203); hepatic dysfunction, which incidence rate was 18.2% (37/203). Conclusions: Albumin-bound paclitaxel single or combination regimen is still significant efficient for various molecular subtypes of breast cancer patients or patients with traditional paclitaxel resistance or multi-line chemotherapy failure. Early usage has better prognosis, controllable adverse reaction and prominent clinical application value.

Improving the productivity of Candida glycerinogenes in the fermentation of ethanol from non-detoxified sugarcane bagasse hydrolysate by a hexose transporter mutant

AIMS

In this study, we attempted to increase the productivity of Candida glycerinogenes yeast for ethanol production from non-detoxified sugarcane bagasse hydrolysates (NDSBH) by identifying the hexose transporter in this yeast that makes a high contribution to glucose consumption, and by adding additional copies of this transporter and enhancing its membrane localisation stability (MLS).

METHODS AND RESULTS

Based on the knockout and overexpression of key hexose transporter genes and the characterisation of their promoter properties, we found that Cghxt4 and Cghxt6 play major roles in the early and late stages of fermentation, respectively, with Cghxt4 contributing most to glucose consumption. Next, subcellular localisation analysis revealed that a common mutation of two ubiquitination sites (K9 and K538) in Cghxt4 improved its MLS. Finally, we overexpressed this Cghxt4 mutant (Cghxt4.2A) using a strong promoter, P_CgGAP , which resulted in a significant increase in the ethanol productivity of C. glycerinogenes in the NDSBH medium. Specifically, the recombinant strain showed 18 and 25% higher ethanol productivity than the control in two kinds of YP-NDSBH medium (YP-NDSBH1_G160 and YP-NDSBH2_G160 ), respectively.

CONCLUSIONS

The hexose transporter mutant Cghxt4.2A (Cghxt4^K9A,K538A ) with multiple copies and high MLS was able to significantly increase the ethanol productivity of C. glycerinogenes in NDSBH.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide a promising strategy for constructing efficient strains for ethanol production.

[Construction and analysis of competitive endogenous RNA regulatory network related to gastric cancer]

Objective: To construct the competitive endogenous RNA (ceRNA) network related to gastric cancer and explore the molecular mechanism. Methods: The expression profiles of lncRNA, miRNA and mRNA in gastric cancer and paracancer tissues were analyzed by biochip technology, edgeR package in R software was used to filtrate differential expression genes (multiple change of >1.5 times, P<0.05) and volcano map was drawn. Based on the online miRNA-lncRNA prediction tool lncBase database and the miRNA Target gene prediction database (miRTarBase, target-scan, miRDB, starBase), the relationship between miRNA, lncRNA and mRNA was predicted. Cytoscape software was used to construct lncRNA-miRNA-mRNA ceRNA network and key genes (hub genes) were identified based on cytohubba calculation of degree score of each node. Then Hub genes related to the prognosis of gastric cancer were verified in the TCGA database. The GO and KEGG enrichment analysis of differentially expressed mRNA was performed using the online biological information annotation database DAVID, P<0.05 and false discovery rate (FDR)<0.05 were used as cut-off criteria. R software was used to download the RNA sequencing data and mirna-seq data of gastric cancer and adjacent tissues in TCGA database, edgeR package was used to screen out differentially expressed mRNA, miRNA and lncRNA, and some differentially expressed genes in our data were verified. In OncoLnc database, STAD project of TCGA data was selected and hub gene was input. Patients were divided into two groups based on the median value for hub genes and Kaplan-meier analysis was performed. Results: The differentially expressed 766 mRNA, 110 lncRNA and 10 miRNA were screened out, among them 90 mRNA, 4 lncRNA and 6 miRNA were used to construct the ceRNA network, and 2 of the 20 hub genes were related to the prognosis of patients. MLK7-AS1, SPP1, SULF1, hsa-miR-1307-3p were upregulated in gastric cancer tissues from our biochip, while MT2A, MT1X were downregulated, which were consistent with the results of TCGA gastric cancer database. The differentially expressed mRNAs were significantly enriched in the biological process (BP) and the mineral absorption pathway. CHST1 was negatively correlated while miR-183-5p was positively corelated with the survival of patients. Conclusion: The establishment of ceRNA network for gastric cancer is conducive to further understanding of the molecular biological mechanism. CHST1 and miR-183-5p can be used as prognostic factors of gastric cancer.

[Influence of apatinib and VEGFR2-906T>C polymorphism on clinical outcomes of advanced non-small cell lung cancer patients]

Objective: To investigate the clinical outcomes of advanced non-small cell lung cancer (NSCLC) treated by apatinib regimens and the influence of VEGFR2-906T>C polymorphism. Methods: A total of 109 patients with advanced NSCLC who were treated by apatinib after three and more lines from March 2015 to December 2017 in the Department of Oncology of the First Affiliated Hospital of Zhengzhou University were included in this study. Overall response rates were evaluated after 2 cycles, then progression free survival (PFS) and overall survival (OS) were investigated, and safety data were recorded. Additionally, peripheral blood and the biopsy tissue specimens of some NSCLC patients were collected for the genotyping of genetic variation and VEGFR2 gene mRNA expression, respectively. The association between genotype and other characteristics and VEGFR2 gene mRNA expression were analyzed. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate analysis were adjusted by Cox regression analysis. Results: The treatment effect could be evaluated in all the 109 patients, among them, complete remission (CR) 0 case, partial remission (PR) 19 case, stable disease (SD) 58 case, progression disease (PD) 32 case. Overall response rate (ORR) was 17.43%, disease control rate (DCR) was 70.64%, median PFS was 4.35 months, median OS was 8.35 months. Of the polymorphisms analyzed, only -906T>C was of clinical significance. The prevalence of -906T>C in VEGFR2 among the study population were as follows: TT genotype 64 cases (58.72%), TC genotype 37 cases (33.94%), CC genotype 8 cases (7.34%), minor allele frequency of -906T>C was 0.24. The distribution of three genotypes was in accordance with Hardy-Weinberg Equilibrium (P=0.418). CC and TC genotype patients were merged in the comparison of clinical outcomes. The analysis of patients with different genotypes found that the ORR of CC/TC genotypes and TT genotypes were 13.33% and 20.31% (P=0.377), respectively. And the median PFS of patients with CC/TC genotype and TT genotype were 3.25 and 5.35 months, respectively, which was statistically significant (P=0.007). In terms of OS, the median OS of the two genotypes were 7.35 and 9.15 (P=0.014), respectively. Adjusted in multivariate Cox regression analysis of PFS, TC/CC genotypes were an independent factor for PFS (OR=1.83, P=0.015). The correlation between -906T>C and adverse reactions was not found in the safety analysis. Additionally, of the 69 biopsy tissue specimens, gene expression analysis was conducted. And the results show that the mRNA expression of VEGFR2 in cancer tissues of the patients with CC/TC genotypes were significantly higher than those of the TT genotype patients (P<0.001). Conclusions: Apatinib is safe and effective for patients with advanced non-small cell in multiline therapy. VEGFR2 -906T>C CC/TC genotype has a worse effect on apatinib multiline treatment in patients with advanced NSCLC.

Enhanced 1,3-propanediol production in Klebsiella pneumoniae by a combined strategy of strengthening the TCA cycle and weakening the glucose effect

AIMS

This study aimed to strengthen the reducing equivalent generation in Klebsiella pneumoniae for improving 1,3-propanediol (PDO) production.

METHODS AND RESULTS

Disruption of the arcA gene activated the transcription levels of the TCA cycle genes and thus increased the NADH/NAD⁺ ratio by 54·2%, leading to the improved PDO titre and yield per cell from 16·1 g l^-1 and 4·0 g gDCW^-1 to 18·8 g l^-1 and 6·4 g gDCW^-1 respectively. Further ldhA gene deletion eliminated lactate accumulation and promoted the PDO titre to 19·9 g l^-1 . Finally, the glucose effect was weakened by deleting the crr gene to enhance the co-utilization of glucose and glycerol, resulting in the increased PDO production to 23·8 g l^-1 with the glycerol conversion rate of 59·5%. The PDO titre in bioreactor was promoted from 61·2 to 78·1 g l^-1 .

CONCLUSIONS

Deletions of the arcA and the crr genes showed positive effects on the TCA cycle activity and the co-utilization of glucose and glycerol, leading to the strengthened reducing equivalent generation and the improved PDO titre by 47·8% in shaker. The PDO titre in the bioreactor was enhanced to 78·1 g l^-1 .

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided novel information on generating reducing equivalent for the PDO biosynthesis by strengthening the TCA cycle and weakening the glucose effect in K. pneumoniae.

Genomewide differential expression profiling of long non-coding RNAs in androgenetic alopecia in a Chinese male population

BACKGROUND

Androgenetic alopecia (AGA), or male pattern baldness (MPB), is the most common form of hair loss in males. A combination of genetic and androgen causes have been suggested as factors that contribute to the development of AGA. However, the specific molecular mechanisms that underly AGA remain largely unknown. Long non-coding RNAs (lncRNAs), a new class of regulatory non-coding RNAs that are longer than 200 nucleotides, have been shown to play important roles in a number of cellular processes, including transcription, chromosome remodelling and post-transcriptional processing. The dysregulation of lncRNAs is associated with many forms of diseases, but it remains unknown whether lncRNAs are associated with AGA.

OBJECTIVE

The aim of this study was to identify AGA-associated lncRNAs and predict the potential roles of these lncRNAs in AGA.

METHODS

A genomewide microarray was used to identify lncRNAs that are differentially expressed between AGA and adjacent normal tissues. Real-time qRT-PCR was used to validate the microarray data.

RESULTS

A large number of lncRNAs were differentially expressed (fold change >2.4) between AGA and adjacent normal tissues. Of these, 770 were upregulated and 1373 were downregulated. Moreover, pathway analysis revealed that 53 functional pathways were associated with the upregulated transcripts, while 11 pathways were associated with the downregulated transcripts.

CONCLUSION

To our knowledge, this is the first study to investigate AGA-associated lncRNAs. lncRNA profiles are altered in AGA, and these lncRNAs and their target genes may serve as novel candidates for preventing and treating AGA.

Oncogenic effects of evolutionarily conserved noncoding RNA ECONEXIN on gliomagenesis

Accumulating studies have demonstrated the importance of long noncoding RNAs (lncRNAs) during oncogenic transformation. However, because most lncRNAs are currently uncharacterized, the identification of novel oncogenic lncRNAs is difficult. Given that intergenic lncRNA have substantially less sequence conservation patterns than protein-coding genes across species, evolutionary conserved intergenic lncRNAs are likely to be functional. The current study identified a novel intergenic lncRNA, LINC00461 (ECONEXIN) using a combined approach consisting of searching lncRNAs by evolutionary conservation and validating their expression in a glioma mouse model. ECONEXIN was the most highly conserved intergenic lncRNA containing 83.0% homology with the mouse ortholog (C130071C03Rik) for a region over 2500 bp in length within its exon 3. Expressions of ECONEXIN and C130071C03Rik were significantly upregulated in both human and mouse glioma tissues. Moreover, the expression of C130071C03Rik was upregulated even in precancerous conditions and markedly increased during glioma progression. Functional analysis of ECONEXIN in glioma cell lines, U87 and U251, showed it was dominantly located in the cytoplasm and interacted with miR-411-5p via two binding sites within ECONEXIN. Inhibition of ECONEXIN upregulated miR-411-5p together with the downregulation of its target, Topoisomerase 2 alpha (TOP2A), in glioma cell lines, resulting in decreased cell proliferation. Our data demonstrated that ECONEXIN is a potential oncogene that regulates TOP2A by sponging miR-411-5p in glioma. In addition, our investigative approaches to identify conserved lncRNA and their molecular characterization by validation in mouse tumor models may be useful to functionally annotate novel lncRNAs, especially cancer-associated lncRNAs.

Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE)

AIMS/HYPOTHESIS

Up-regulation of the receptor for AGEs (RAGE) and its ligands in diabetes has been observed in various tissues. Here, we sought to determine levels of RAGE and one of its most important ligands, S100B, in diabetic retina, and to investigate the regulatory role of S100B and RAGE in Müller glia.

METHODS

Streptozotocin-diabetes was induced in Sprague-Dawley rats. RAGE, S100B and glial fibrillary acidic protein (GFAP) were detected in retinal cryosections. In parallel, the human retinal Müller cell line, MIO-M1, was maintained in normal glucose (5.5 mmol/l) or high glucose (25 mmol/l). RAGE knockdown was achieved using small interfering RNA (siRNA), while soluble RAGE was used as a competitive inhibitor of RAGE ligand binding. RAGE, S100B and cytokines were detected using quantitative RT-PCR, western blotting, cytokine protein arrays or ELISA. Activation of mitogen-activated protein kinase (MAPK) by RAGE was determined by western blotting.

RESULTS

Compared with non-diabetic controls, RAGE and S100B were significantly elevated in the diabetic retina with apparent localisation in the Müller glia, occurring concomitantly with upregulation of GFAP. Exposure of MIO-M1 cells to high glucose induced increased production of RAGE and S100B. RAGE signalling via MAPK pathway was linked to cytokine production. Blockade of RAGE prevented cytokine responses induced by high glucose and S100B in Müller glia.

CONCLUSIONS/INTERPRETATION

Hyperglycaemia in vivo and in vitro exposure to high glucose induce upregulation of RAGE and its ligands, leading to RAGE signalling, which links to pro-inflammatory responses by retinal Müller glia. These data shed light on the potential clinical application of RAGE blockade to inhibit the progression of diabetic retinopathy.

The insert region of RhoA is essential for Rho kinase activation and cellular transformation

RhoA is involved in multiple cellular processes, including cytoskeletal organization, gene expression, and transformation. These processes are mediated by a variety of downstream effector proteins. However, which effectors are involved in cellular transformation and how these proteins are activated following interaction with Rho remains to be established. A unique feature that distinguishes the Rho family from other Ras-related GTPases is the insert region, which may confer Rho-specific signaling events. Here we report that deletion of the insert region does not result in impaired effector binding. Instead, this insert deletion mutant (RhoDeltaRas, in which the insert helix has been replaced with loop 8 of Ras) acted in a dominant inhibitory fashion to block RhoA-induced transformation. Since RhoDeltaRas failed to promote stress fiber formation, we examined the ability of this mutant to bind to and subsequently activate Rho kinase. Surprisingly, RhoDeltaRas-GTP coprecipitated with Rho kinase but failed to activate it in vivo. These data suggested that the insert domain is not required for Rho kinase binding but plays a role in its activation. The constitutively active catalytic domain of Rho kinase did not promote focus formation alone or in the presence of Raf(340D) but cooperated with RhoDeltaRas to induce cellular transformation. This suggests that Rho kinase needs to cooperate with additional Rho effectors to promote transformation. Further, the Rho kinase catalytic domain reversed the inhibitory effect of RhoDeltaRas on Rho-induced transformation, suggesting that one of the downstream targets of Rho-induced transformation abrogated by RhoDeltaRas is indeed Rho kinase. In conclusion, we have demonstrated that the insert region of RhoA is required for Rho kinase activation but not for binding and that this kinase activity is required to induce morphologic transformation of NIH 3T3 cells.

[The impact of early diagnosis and thrombolytic-anticoagulant therapies on outcome of pulmonary embolism]

OBJECTIVE

To investigate the effect of early diagnosis and thrombolytic followed by anticoagulant therapy in pulmonary embolism (PE).

METHODS

46 patients diagnosed as PE were retrospectively analyzed. All the patients were treated with thrombolytic followed by anticoagulant therapy. Therapeutic effect was compared between two groups of patients with symptoms more or less than two weeks before establishment of diagnosis.

RESULT

36 patients were documented as PE by lung scan, 13 of 46 patients (28.3%) were misdiagnosed as other heart or lung diseases. All the patients had accompanying diseases, including leg deep vein thrombosis (DVT) (33/46, 71.7%) heart or lung diseases other than PE(23/46, 50%), and history of surgery (6/46, 3%). 93.1% of the patients with clinical history less than 2 weeks showed improvement, whereas only 52.9% of those with clinical history exceeding 2 weeks improved. There was significant difference between them.

CONCLUSION

In order to diagnose PE early, we should pay more attention to the risk factors of PE, especially DVT. The success of thrombolysis appears to depend on the interval between the onset of symptoms and start of thrombolytic therapy. Patients with clinical symptoms less than 2 weeks show better improvement.

Glucose toxicity and the development of diabetes in mice with muscle-specific inactivation of GLUT4

Using cre/loxP gene targeting, transgenic mice with muscle-specific inactivation of the GLUT4 gene (muscle GLUT4 KO) were generated and shown to develop a diabetes phenotype. To determine the mechanism, we examined insulin-stimulated glucose uptake and metabolism during hyperinsulinemic-euglycemic clamp in control and muscle GLUT4 KO mice before and after development of diabetes. Insulin-stimulated whole body glucose uptake was decreased by 55% in muscle GLUT4 KO mice, an effect that could be attributed to a 92% decrease in insulin-stimulated muscle glucose uptake. Surprisingly, insulin's ability to stimulate adipose tissue glucose uptake and suppress hepatic glucose production was significantly impaired in muscle GLUT4 KO mice. To address whether these latter changes were caused by glucose toxicity, we treated muscle GLUT4 KO mice with phloridzin to prevent hyperglycemia and found that insulin-stimulated whole body and skeletal muscle glucose uptake were decreased substantially, whereas insulin-stimulated glucose uptake in adipose tissue and suppression of hepatic glucose production were normal after phloridzin treatment. In conclusion, these findings demonstrate that a primary defect in muscle glucose transport can lead to secondary defects in insulin action in adipose tissue and liver due to glucose toxicity. These secondary defects contribute to insulin resistance and to the development of diabetes.

Photocatalytic degradation of AZO dyes by supported TiO2 + UV in aqueous solution

The photocatalytic degradation performance of photocatalysts TiO2 supported on 13-X, Na-Y, 4A zeolites with different loading content was evaluated using the photocatalytic oxidation of dyes direct fast scarlet 4BS and acid red 3B in aqueous medium. The results showed that the best reaction dosage of TiO2-zeolite catalysts is about 2 g/l and the photocatalytic kinetics follows first order for all supported catalysts. The photocatalytic activity order of the three series catalysts is 13X type >Y type >4A type. The physical state of titanium dioxide on the supports is evaluated by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD), BET, and FTIR.

Structure and chromosomal localization of the human glycogenin-2 gene GYG2

Glycogenin-2 is one of two self-glucosylating proteins involved in the initiation phase of the synthesis of the storage polysaccharide glycogen. Cloning of the human glycogenin-2 gene, GYG2, has revealed the presence of 11 exons and a gene of more than 46 kb in size. The structure of the gene explains much of the observed diversity in glycogenin-2 cDNA sequences as being due to alternate exon usage. In some cases, there is variation in the splice junctions used. Over regions of protein sequence similarity, the GYG2 gene structure is similar to that of the other glycogenin gene, GYG. A genomic GYG2 clone was used to localize the gene to Xp22.3 by fluorescence in-situ hybridization. Localization close to the telomere of the short arm of the X chromosome is consistent with mapping information obtained from glycogenin-2 STS sequences. Glycogenin-2 maps between the microsatellite anchor markers AFM319te9 (DXS7100) and AFM205tf2 (DXS1060), and its 3' end is 34.5 kb from the 3' end of the arylsulphatase gene ARSD. GYG2 is outside the pseudoautosomal region PAR1 but still in a region of X-Y shared genes. As is true for several other genes in this location, an inactive remnant of GYG2, consisting of exons 1-3, may be present on the Y chromosome.

Loop 6 of RhoA confers specificity for effector binding, stress fiber formation, and cellular transformation

Rho family GTPases regulate multiple cellular processes, including cytoskeletal organization, gene expression, and transformation. These effects are achieved through the interaction of GTP-bound proteins with various downstream targets. A series of RhoA/Rac1 and Rho/Ras chimeras was generated to map the domain(s) of RhoA involved in its association with two classes of effector kinase, represented by PRK2 and ROCK-I. Although the switch 1 domain was required for effector binding, the N terminus of Rho (residues 1-75) was interchangeable with that of Rac. This suggested that the region of Rho that confers effector binding specificity lay further C-terminal. Subsequent studies indicated that the "insert domain"(residues 123-137), a region unique to Rho family GTPases, is not the specificity determinant. However, a determinant for effector binding was identified between Rho residues 75-92. Rac to Rho point mutations (V85D or A88D) within loop 6 of Rac promoted its association with PRK2 and ROCK, whereas the reciprocal Rho(D87V/D90A) double mutant significantly reduced effector binding capacity. In vivo studies showed that microinjection of Rac(Q6IL/V85D/A88D) but not Rac(Q6IL) induced stress fiber formation in LLC-PK epithelial cells, suggesting that loop 6 residues conferred the ability of Rac to activate ROCK. On the other hand, the reciprocal Rho (Q6IL/D87V/D90A) mutant was defective in its ability to transform NIH 3T3 cells. These data suggest that although Rho effectors can utilize a Rho or Rac switch 1 domain to sense the GTP-bound state of Rho, unique residues within loop 6 are essential for determining both effector binding specificity and cellular function.

[Studies on immunoprotection of monoclonal antibodies against Cryptosporidium parvum]

AIM

To explore the immune protection of the monoclonal antibody (McAb) against Cryptosporidium parvum.

METHODS

On the basis of Madin-Darby canine kidney (MDCK) cell culture, the immunoprotection of McAb against C. parvum was screened by means of neutralization test in vitro, and verified by rat model and transmission electron microscopy of infected MDCK cells.

RESULTS

The number of C. parvum sporozoites recovered on the surface of rat intestinal epithelial cells and the mean output of oocyst were significantly reduced by McAb Z3D2 (P < 0.001, P < 0.05). The decreased Cryptos poridium at each development phase within infected MDCK cells and less damage of cell ultrastructure caused by Cryptosporidium were found in Z3D2 treated group.

CONCLUSION

McAb Z3D2 possesses highly effective protection against C. parvum.

[Preparation and characterization of monoclonal antibodies against Cryptosporidium parvum]

AIM

To develop and characterize the monoclonal antibodies(McAbs) against Cryptosporidium parvum (C. parvum).

METHODS

BALB/c mice were immunized with purified oocyst antigens of C. parvum from human isolates and McAbs against C. parvum were prepared by using hybridoma technique. The characterization of McAbs was studied by means of indirect immunofluorescent assay (IFA) and Western blot analysis.

RESULTS

Four clones of hybridoma cell lines secreting McAbs against oocyst antigens of C. parvum were obtained. The immunoglobulin subclasses of these four McAbs were identified as IgM (Z4C8,Z3D7) and IgG1(Z2B6,Z3D2) and their light chains were kappa chain. IFA results showed that three McAb (Z4C8, Z3D7 and Z3D2) conjugates produced a diffuse fluorescence in the Cryptosporidium sporozoites (CSP) and one (Z2B6) produced local fluorescence in the oocyst wall of C. parvum. Four McAbs could recognize 4 of 42 polypeptide antigen bands of CSP with molecular weights of 20.5 kDa, 33 kDa, 60.5 kDa and 95 kDa, among which both Z4C8 and Z3D7 could recognize 20.5 kDa band that was defined as a principal antigenic protein of CSP.

CONCLUSION

These four McAbs possess their own characteristics of recognizing antigenic epitopes on CSP, but react specifically against antigens of C. parvum.