Role of lactadherin anti-idiotypic monoclonal antibodies Ab2β in the treatment of human rotavirus-induced diarrhea in a neonatal mouse model / 中国热带医学

@#Abstract: Objective To investigate the preventive and therapeutic effects of anti-idiotypic monoclonal antibodies (Ab2β) of lactadherin on neonatal mice infected with human rotavirus (HRV), and to analyze the underlying mechanism. Methods Hybridoma technology was used to prepare Ab2β of lactadherin. One hundred and twenty 7-day-old Kunming mice were randomly divided into groups A, B, C and control, each consisting of 30 mice. Groups A, B, and C were all infected with HRV via oral gavage. Group A received no treatment, group B was orally administered lactadherin for 7 days prior to infection, and group C was orally administered lactadherin for 7 days after infection, the control group was orally administered cell culture medium that did not contain the virus. The clinical manifestations (diarrhea, body weight) at different time points after infection of the neonatal mice in each group were observed, and the content of rotavirus antigen in the feces of neonatal mice was detected by enzyme-linked immunosorbent assay (ELISA). After HRV infection for 7 days, immunohistochemical staining was used to examine the expression level of intercellular adhesion molecule-1 (ICAM-1) in mouse small intestinal tissues in each group. Results No diarrhea occurred in the control group at any time point. Groups A, B, and C showed diarrhea symptoms after HRV challenge for 1 day. The degree of diarrhea in groups B and C was lower than that in group A at 2-4 days after HRV challenge, and the difference was statistically significant (P<0.05). The HRV antigen content in the feces of the neonatal mice in groups B and C was lower than that in group A at 1-5 days after HRV challenge, and the difference was statistically significant (P<0.05). There was no significant difference in the degree of diarrhea and HRV antigen content between groups B and C at each time point (P>0.05). There was no significant difference in the body weight of the neonatal mice in each group before infection and 1 day after infection (P>0.05); the weight of neonatal mice in groups B and C was higher than that in group A at 3, 5 and 7 days after HRV challenge, and the difference was statistically significant (P<0.05), and there was no significant difference in body weight between groups B and C at each time point after HRV challenge (P>0.05). The number of ICAM-1 expressing cells in the small intestine of the three groups A, B, and C was higher than that of the control group after HRV challenge for 7 days, and the difference was statistically significant (P<0.05). The cell number and gray value of ICAM-1 expressing cells in groups B and C were lower than those in group A, and the difference was statistically significant (P<0.05). Conclusions Anti-idiotypic monoclonal antibodies (Ab2β) of lactadherin has a good preventive and therapeutic effects on human rotavirus infection in neonatal mice, and can significantly improve diarrhea symptoms and reduce HRV viral load. Its specific mechanism may be related to the inhibition of ICAM-1.

Role of lactadherin anti-idiotypic monoclonal antibodies Ab2β in the treatment of human rotavirus-induced diarrhea in a neonatal mouse model / 中国热带医学

@#Abstract: Objective To investigate the preventive and therapeutic effects of anti-idiotypic monoclonal antibodies (Ab2β) of lactadherin on neonatal mice infected with human rotavirus (HRV), and to analyze the underlying mechanism. Methods Hybridoma technology was used to prepare Ab2β of lactadherin. One hundred and twenty 7-day-old Kunming mice were randomly divided into groups A, B, C and control, each consisting of 30 mice. Groups A, B, and C were all infected with HRV via oral gavage. Group A received no treatment, group B was orally administered lactadherin for 7 days prior to infection, and group C was orally administered lactadherin for 7 days after infection, the control group was orally administered cell culture medium that did not contain the virus. The clinical manifestations (diarrhea, body weight) at different time points after infection of the neonatal mice in each group were observed, and the content of rotavirus antigen in the feces of neonatal mice was detected by enzyme-linked immunosorbent assay (ELISA). After HRV infection for 7 days, immunohistochemical staining was used to examine the expression level of intercellular adhesion molecule-1 (ICAM-1) in mouse small intestinal tissues in each group. Results No diarrhea occurred in the control group at any time point. Groups A, B, and C showed diarrhea symptoms after HRV challenge for 1 day. The degree of diarrhea in groups B and C was lower than that in group A at 2-4 days after HRV challenge, and the difference was statistically significant (P<0.05). The HRV antigen content in the feces of the neonatal mice in groups B and C was lower than that in group A at 1-5 days after HRV challenge, and the difference was statistically significant (P<0.05). There was no significant difference in the degree of diarrhea and HRV antigen content between groups B and C at each time point (P>0.05). There was no significant difference in the body weight of the neonatal mice in each group before infection and 1 day after infection (P>0.05); the weight of neonatal mice in groups B and C was higher than that in group A at 3, 5 and 7 days after HRV challenge, and the difference was statistically significant (P<0.05), and there was no significant difference in body weight between groups B and C at each time point after HRV challenge (P>0.05). The number of ICAM-1 expressing cells in the small intestine of the three groups A, B, and C was higher than that of the control group after HRV challenge for 7 days, and the difference was statistically significant (P<0.05). The cell number and gray value of ICAM-1 expressing cells in groups B and C were lower than those in group A, and the difference was statistically significant (P<0.05). Conclusions Anti-idiotypic monoclonal antibodies (Ab2β) of lactadherin has a good preventive and therapeutic effects on human rotavirus infection in neonatal mice, and can significantly improve diarrhea symptoms and reduce HRV viral load. Its specific mechanism may be related to the inhibition of ICAM-1.

Virus isolation and genotype identification of human respiratory syncytial virus in Guizhou Province, China

ABSTRACT To investigate the genetic variation and molecular epidemiology characteristics of Human Respiratory Syncytial Virus (HRSV) in Guizhou Province, nasopharyngeal aspirates were collected from patients with acute respiratory infection (ARI) in Guizhou Provincial People's Hospital, from December 2017 to March 2018, and inoculated to Hep-2 cells to isolate HRSV. Cells that showed cytopathic effect (CPE) were then confirmed by indirect immunofluorescence assay and reverse transcription. The sequence of the PCR products was determined for HRSV isolates, and the genetic variation was analyzed. Out of 196 nasopharyngeal aspirate samples, HRSV were isolated in 39. The second hypervariable region at the 3' terminal of glycoprotein gene (HVR2) sequence analysis showed that subgroup A was dominant. Seventy-nine percent of the isolates belonged to subgroup A, ON1 genotype, and 21 % belonged to subgroup B, BA9 genotype, which indicates that the dominant HRSV circulating in Guizhou Province was subgroup A, genotype ON1, co-circulating with a less prevalent subgroup B, genotype BA9.

Visualization of the ribosomal DNA (45S rDNA) of Indica rice with FISH on some phases of cell cycle and extended DNA fibers

The ribosomal DNA (45S rDNA) behaviors during the cell cycle were analyzed on interphase nuclei, prophases, metaphases, pachytene chromosomes and extended DNA fibers in rice (Oryza,sativa ssp.indica cv.Guangluai No.4) by using high-resolution fluorescent in situ hybridization (FISH). The results show that 45S rDNA is located at the ends of short arms of chromosomes 9 and 10. But the signals are much more intense on chromosome 9 than on chromosome 10 in metaphase. Pachytene chromosome has rDNA signal arrays on chromosome 9. Different phases are described and discussed. These results indicate that the activity of rDNA at individual loci may also vary through the cell cycle in rice. on extended DNA fibers, 45S rDNA signals appear as strings of numerous red spots, but some signals are missed in some regions, probably result from weak signals or intergenic spacers