Effect of HCMV infection on immune reconstitution of CD8+T cells in children with allogeneic hematopoietic stem cell transplantation / 中华预防医学杂志

Objective: To investigate the risk factors for human cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation in children and the impact of human cytomegalovirus infection on post-transplant immune reconstitution. Methods: A Retrospective Co-Hort study design was used to include 81 children treated with allo-HSCT from January 2020 to March 2022 at the Department of Hematology, Capital Institute of Pediatrics, Beijing, China, and followed up for 1 year. Real-time quantitative PCR was used to detect positive detection of HCMV in children after allo-HSCT, multifactorial logistic regression modeling was used to analyze the risk factors leading to HCMV infection, and generalized estimating equation modeling was used to analyze the effect of HCMV infection on the T-cells of the children who received allo-HSCT. Results: The age M(Q1, Q3) of 81 children was 5.1 years (10 months, 13.8 years), and 50 (61.7%) were male. By the endpoint of follow-up, a total of 50 HCMV-positive cases were detected, with an HCMV detection rate of 61.7%; The results of multifactorial logistic regression modeling showed that children with grade 2-4 aGVHD had a higher risk of HCMV infection compared with grade 0-1 after transplantation [OR (95%CI) value: 2.735 (1.027-7.286)]. The results of generalized estimating equation modeling analysis showed that the number of CD3+T cells in HCMV-positive children after transplantation was higher than that in the HCMV-negative group [RR (95%CI) value: 1.34 (1.008-1.795)]; the ratio of CD4+T/CD8+T cells was smaller than that in the HCMV-negative group [RR (95%CI) value: 0.377 (0.202-0.704)]; the number of CD8+T cells was higher than that in the HCMV-negative group [RR (95%CI) value: 1.435 (1.025-2.061)]; the number of effector memory CD8+T cells was higher than that in the HCMV-negative group [RR (95%CI) value: 1.877 (1.089-3.236)]. Conclusion: Acute graft-versus-host disease may be a risk factor for HCMV infection in children after allo-HSCT; post-transplant HCMV infection promotes proliferation of memory CD8+T-cell populations and affects immune cell reconstitution.

Effect of HCMV infection on immune reconstitution of CD8+T cells in children with allogeneic hematopoietic stem cell transplantation / 中华预防医学杂志

Objective: To investigate the risk factors for human cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation in children and the impact of human cytomegalovirus infection on post-transplant immune reconstitution. Methods: A Retrospective Co-Hort study design was used to include 81 children treated with allo-HSCT from January 2020 to March 2022 at the Department of Hematology, Capital Institute of Pediatrics, Beijing, China, and followed up for 1 year. Real-time quantitative PCR was used to detect positive detection of HCMV in children after allo-HSCT, multifactorial logistic regression modeling was used to analyze the risk factors leading to HCMV infection, and generalized estimating equation modeling was used to analyze the effect of HCMV infection on the T-cells of the children who received allo-HSCT. Results: The age M(Q1, Q3) of 81 children was 5.1 years (10 months, 13.8 years), and 50 (61.7%) were male. By the endpoint of follow-up, a total of 50 HCMV-positive cases were detected, with an HCMV detection rate of 61.7%; The results of multifactorial logistic regression modeling showed that children with grade 2-4 aGVHD had a higher risk of HCMV infection compared with grade 0-1 after transplantation [OR (95%CI) value: 2.735 (1.027-7.286)]. The results of generalized estimating equation modeling analysis showed that the number of CD3+T cells in HCMV-positive children after transplantation was higher than that in the HCMV-negative group [RR (95%CI) value: 1.34 (1.008-1.795)]; the ratio of CD4+T/CD8+T cells was smaller than that in the HCMV-negative group [RR (95%CI) value: 0.377 (0.202-0.704)]; the number of CD8+T cells was higher than that in the HCMV-negative group [RR (95%CI) value: 1.435 (1.025-2.061)]; the number of effector memory CD8+T cells was higher than that in the HCMV-negative group [RR (95%CI) value: 1.877 (1.089-3.236)]. Conclusion: Acute graft-versus-host disease may be a risk factor for HCMV infection in children after allo-HSCT; post-transplant HCMV infection promotes proliferation of memory CD8+T-cell populations and affects immune cell reconstitution.

Study on the phenomenon of splashes and sprays from virology / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the phenomenon of accidental splashes and sprays from manipulation of recombinant virus material and to measure the approximate spilled distance when recombinant virus material inadvertently dropped in the biosafety laboratory.</p><p><b>METHODS</b>first, two groups owning different experience simulated the course of accidental spills and splashes by recombinant adenovirus (rADV) which expressed green fluorescence protein (GFP), the GFP signal were observed in 96 well cell plate after spills appeared; Second, the routine two heights (75 cm and 110 cm) and capacity (1 ml, 1.5 ml, 4 ml and 8 ml) of virus were chose to simulate the experiment of unexpected dropping.</p><p><b>RESULTS</b>First, the positive quantity of the first group owning 5 years' experience is much less than the second group owning 2 years' work experience, the former was 7 positive wells, the latter was 81 positive when they used the pipette to operation. Second, when the unclosed test tubes (1 ml, 1.5 ml, 4 ml and 8 ml recombinant virus) inadvertently dropped, the largest spill distance was 0.92 m, 1.57 m, 2.63 m and2.68 m respectively.</p><p><b>CONCLUSION</b>The better experience is important to make sure safety when we make infectious material; the contaminated distance increased with the amount of recombinant virus material.</p>

Molecular interaction between PrP protein and the signal protein 14-3-3 beta / 病毒学报

The molecular interaction between PrP and 14-3-3 beta and the possible interactional domain between two proteins were studied by co-immunoprecipitation, pull down and FRET assays. The results showed that PrP protein could interact with 14-3-3 beta in vitro and in vivo. The domain which responded for the interaction was located at C-terminal of PrP (amino acid residues 106 to 126). This study of the interaction between PrP and 14-3-3 protein further provided the insight into the potential role of 14-3-3 in the biological function of PrP and the pathogenesis of prion disease.

Preparations of the specific antibodies against exon 2 and exon 3 of human tau protein / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To prepare the specific antibodies against exon 2 and exon 3 of human tau protein.</p><p><b>METHODS</b>Sequences encoding exon 2 and exon 3 of human tau protein were amplified from human peripheral blood DNA and cloned into a prokaryotic expression vector pGEX-2T. Fusion proteins GST-E2 and GST-E3 were expressed and purified from E. coli system. The antisera were elicited by immunization of the purified fusion proteins to rabbits and mice. The specific antibodies were purified by Protein G/A and CNBr-activated sepharose 4B coupled with GST protein. The specificity and sensitivity of the purified antibodies were evaluated by Western blotting and ELISA.</p><p><b>RESULTS</b>Recombinant fusion proteins GST-E2 and GST-E3 were expressed and purified from E. coli, which showed Mr. 29 x 10(3). Various antisera were collected from the immunized experimental animals. Reliable immunoreactive specificity and titers of the purified antibodies against exon 2 and exon 3 of human tau protein were confirmed by Western blotting and ELISA after serial purification processes.</p><p><b>CONCLUSION</b>Four specific antibodies against exon 2 and exon 3 of human tau protein have been successfully prepared, which provides basis for analyzing the role of tau in neurodegenerative diseases.</p>

Investigating the risk of two model virus in the laboratory / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the survival time of recombination rival in environment and inactivation ability of different disinfectant and ultraviolet radiation against virus.</p><p><b>METHODS</b>NC membranes absorbed the recombinant adenovirus (rADV) or herpes simplex virus (rHSV) with green fluorescence protein (GFP) were laid, or immersed in various concentration of different disinfectants such as ethanol, sodium hypochlorite, lysol and geramine and then taked out them every 15 min, or exposed under ultraviolet radiation, then the NC membranes were adsorbed 1 h in cell, 37 degrees C 5% CO2 48 h. The results were observed under the fluorescence microscope.</p><p><b>RESULTS</b>(1) the average survival time of rHSV under environment is less than 60 min, rADV is almost up to 2 h. (2) The infection ability of rHSV and rADV was inactived 15 min by both ethanol (100%, 70% and 50%) and sodium hypochlorite (5%, 2.5% and 1.25%). (3) Two virus can be killed by 0.1% bromogeramine. (4) Both 5% and 2.5% lysol, but rADV can not lost the infection on Vero Cell until 75 min by 1.25% Lysol. (5) The rHSV was inactivated under ultraviolet radiation, but rADV was not.</p><p><b>CONCLUSION</b>The survival time of is different from both envelope rival and the no-envelope viral under nature environment and the inactivate ability of disinfectant also is different between two model virus; Disinfectant should be choose according to virus type.</p>

The construction and identification of the PRNP vectors with ubiquitin or the lysosome-targeting signal / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To evaluate PrP expression characteristic of PRNP nucleic acid vaccine vector with ubiquitin or the lysosome-targeting signal.</p><p><b>METHODS</b>The gene of ubiquitin and lysosome-targeting signal were ligated to PRNP and pcDNA3.1 vector that is, pcDNA3.1-UPrP and pcDNA3.1-PrPL were constructed. The expression characteristics of PrP with two signals were evaluated by Western Blot and the localization was observed by indirect immune fluorescence.</p><p><b>RESULTS</b>The protein expressed by pcDNA3.1-UPrP and pcDNA3.1-PrPL with ubiquitin and lysosome-targeting signal can be recognized by prion-specific antibody. The protein has three glycosylation molecules form as native PrP.PrP with ubiquitin was degraded gradually with time extension,whereas quantity of PrP with lysosome signal reduced in 48 h after transfection. The protein with two location signals can direct fusion proteins to cytoplasm.</p><p><b>CONCLUSION</b>The PRNP vectors with ubiquitin or the lysosome-targeting signal were constructed and expressed in eukaryocyte successfully. There will be one of good foundation on PRNP nucleic acid vaccine.</p>