Simulating immunosuppressive mechanism of Microplitis bicoloratus bracovirus coordinately fights Spodoptera frugiperda

Parasitoid wasps control pests via a precise attack leading to the death of the pest. However, parasitoid larvae exhibit self-protection strategies against bracovirus-induced reactive oxygen species impairment. This has a detrimental effect on pest control. Here, we report a strategy for simulating Microplitis bicoloratus bracovirus using Mix-T dsRNA targeting 14 genes associated with transcription, translation, cell-cell communication, and humoral signaling pathways in the host, and from wasp extracellular superoxide dismutases. We implemented either one-time feeding to the younger instar larvae or spraying once on the corn leaves, to effectively control the invading pest Spodoptera frugiperda. This highlights the conserved principle of "biological pest control," as elucidated by the triple interaction of parasitoid-bracovirus-host in a cooperation strategy of bracovirus against its pest host.

[Analysis of surgical treatment of severe angular kyphosis with keeping the spinal cord length constant in osteotomy area]

Objective: To explore the surgical methods and clinical outcomes of severe angular kyphosis with the length of the spinal cord constant in the osteotomy area. Methods: Clinical data from 20 patients with severe angular kyphosis who underwent surgical treatment from January 2017 to December 2020 in the Department of Spinal Surgery,Hangzhou Xiaoshan District Hospital of Traditional Chinese Medicine were retrospectively analyzed. There were 11 males and 9 females, aged (28.5±8.9) years (range:17 to 46 years).There were 15 cases with congenital angular kyphosis,5 cases with tuberculous angular kyphosis.The angle of kyphosis was (107.1±12.9)° (range:93.2° to 131.4°).Frankel classification:2 cases with grade B,4 cases with grade C,3 cases with grade D.The kyphotic vertex is located at the T₉ to T₁₂ segments.Pedicle screws were placed in 3 or 4 adjacent segments at the proximal and distal kyphosis apex of the patients using a surgical navigation system.Piezosurgery combined with a grinding drill was used to complete the osteotomy in the apical vertebral region.Titanium mesh or artificial vertebral body was implanted,and the osteotomy surface was closed using this as the fulcrum to complete osteotomy.Spinal X-ray examination was performed before surgery,immediately after surgery and at the last follow-up,and sagittal and coronal Cobb angle,sagittal and coronary balance parameters,anterior vertebral height,posterior vertebral height,and spinal cord length were measured.Pulmonary function,visual analogue scale (VAS),and Oswestry's disability index (ODI) were collected and estimated before and after treatment.The analysis of variance of repeated measurement data was used for each evaluation index before and after treatment,and the t test was used for pairwise comparison. Results: All patients successfully completed surgery,with artificial vertebral body in 11 cases and double titanium mesh in 9 cases.The follow-up time was (28.2±2.3) months (range:26 to 31 months).Sagittal vertical axis improved from (46.9±13.7)mm(range:21.7 to 75.7 mm) before surgery to (10.7±5.5)mm (range:3.6 to 28.1 mm) after surgery,and (11.0±5.7)mm(range:3.6 to 29.3 mm) at the last follow-up,the differences were statistically significant compared to before surgery (all P<0.01).The mean kyphotic Cobb angle was corrected from (107.1±12.9) ° (range:93.2 ° to 131.4°) before surgery to (30.6±8.5) ° (range:20.0 ° to 47.8 °) after surgery (all P<0.01),and (32.1±8.7) ° (range:18.2 ° to 50.8°) at the last follow-up,the differences were statistically significant compared to before surgery(all P<0.01).The anterior vertebral height improved from (14.2±2.9)mm(range:11.04 to 23.6 mm) before surgery to (45.3±7.5)mm(range:29.4 to 56.5 mm) after surgery,and (44.3±6.8)mm(range:29.6 to 56.0 mm) at the last follow-up,the differences were statistically significant compared to before surgery (all P<0.01).The posterior vertebral height was improved from (51.8±5.3)mm (range:43.1 to 61.4 mm)before surgery to (57.6±4.7)mm (range:45.7 to 64.1 mm)after surgery,and (56.3±5.0) mm (range:49.7 to 68.5 mm) at the last follow-up,the differences were statistically significant compared to before surgery (all P<0.01).The spinal cord length of the osteotomy segment was (73.1±12.0)mm (range:56.8 to 98.4 mm) before surgery and (74.8±12.8)mm (range:53.5 to 100.2 mm) after surgery and (75.2±13.7)mm (range:53.9 to 102.4 mm) at the last follow-up,the difference was not statistically significant among them(F=0.144,P=0.866).The ODI and VAS scores improved significantly after surgery and at the last follow-up,and the differences were statistically significant (all P<0.01). Conclusion: The posterior vertebral column resection technique combined with titanium mesh or an artificial vertebral body implant for the treatment of severe angular kyphosis can significantly improve the kyphosis,neurological function,and life quality of patients without affecting the length of the spinal cord.

Bracovirus Sneaks Into Apoptotic Bodies Transmitting Immunosuppressive Signaling Driven by Integration-Mediated eIF5A Hypusination

A typical characteristics of polydnavirus (PDV) infection is a persistent immunosuppression, governed by the viral integration and expression of virulence genes. Recently, activation of caspase-3 by Microplitis bicoloratus bracovirus (MbBV) to cleave Innexins, gap junction proteins, has been highlighted, further promoting apoptotic cell disassembly and apoptotic body (AB) formation. However, whether ABs play a role in immune suppression remains to be determined. Herein, we show that ABs transmitted immunosuppressive signaling, causing recipient cells to undergo apoptosis and dismigration. Furthermore, the insertion of viral–host integrated motif sites damaged the host genome, stimulating eIF5A nucleocytoplasmic transport and activating the eIF5A-hypusination translation pathway. This pathway specifically translates apoptosis-related host proteins, such as P53, CypA, CypD, and CypJ, to drive cellular apoptosis owing to broken dsDNA. Furthermore, translated viral proteins, such Vank86, 92, and 101, known to complex with transcription factor Dip3, positively regulated DHYS and DOHH transcription maintaining the activation of the eIF5A-hypusination. Mechanistically, MbBV-mediated extracellular vesicles contained inserted viral fragments that re-integrated into recipients, potentially via the homologous recombinant repair system. Meanwhile, this stimulation regulated activated caspase-3 levels via PI3K/AKT 308 and 473 dephosphorylation to promote apoptosis of granulocyte-like recipients Sf9 cell; maintaining PI3K/AKT 473 phosphorylation and 308 dephosphorylation inhibited caspase-3 activation leading to dismigration of plasmatocyte-like recipient High Five cells. Together, our results suggest that integration-mediated eIF5A hypusination drives extracellular vesicles for continuous immunosuppression.

Interactions of Vank proteins from Microplitis bicoloratus bracovirus with host Dip3 suppress eIF4E expression

Microplitis bicoloratus bracovirus (MbBV) inhibits the immune response of the host Spodoptera litura by disrupting nuclear factor (NF)-κB signaling and downstream gene expression. However, the underlying molecular mechanisms are not well understood. Herein, we report that viral ankyrin (Vank) proteins interacted with host dorsal-interacting protein 3 (Dip3) to selectively inhibit the transcription of eukaryotic translation initiation factor 4 E (eIF4E). Dip3 and Vank proteins were co-expressed and colocalized in the nucleus. Furthermore, ectopic expression of Dip3 rescued the transcription of some NF-κB-dependent genes suppressed by Vank proteins, including eIF4E. Co-immunoprecipitation and pull-down assays confirmed that Vank proteins interacted with and bound to full-length Dip3, which including MADF, DNA-binding protein, BESS, and protein-protein interaction motifs as well as non-motif sequences. In vivo, RNAi-mediated dip3 silencing decreased eIF4E levels and was accompanied by an immunosuppressive phenotype in S. litura. Our results provided novel insights into the regulation of host transcription during immune suppression by viral proteins that modulate nuclear NF-κB signaling.

[Effect of xiaoyin jiedu yin on Staphylococcus aureus enterotoxin B induced serum interleukin 8 in mice]

OBJECTIVE

To explore the therapeutic mechanism of Xiaoyin Jiedu Yin (XYJDY) in treating psoriasis.

METHODS

Abnormal elevation of interleukin 8 (IL-8) level in mice was induced by Staphylococcus aureus enterotoxin B (SEB), then the antagonizing effects of XYJDY and Composite Qingdai Capsule were observed.

RESULTS

Serum IL-8 level arose and reached the peak 3-5 hrs after SEB induction. XYJDY could antagonize the induction significantly, and the effect was more significant when large dosage was given.

CONCLUSION

XYJDY, in either large or small dose, could effectively antagonize the SEB induction on IL-8. Applying with superantigen theory, this fact could be used to elucidate the mechanism of XYJDY in removing Heat, cooling blood and detoxifying at cell biologic level.

All-trans-retinoic acid increased the expression of integrin alpha5beta1 and induced "anoikis" in SMMC-7721 hepatocarcinoma cell

It is extensively shown that integrin can regulate various cellular functions, including apoptosis, probably by contributing to signal transduction processes through interaction with extracellular matrix (ECM) proteins. In the present study, DNA flow cytometric analysis demonstrated that SMMC-7721 hepatocarcinoma cells treated with 80 microM all-trans-retinoic acid (atRA) showed an increased expression of the integrin alpha5beta1, which was associated with the growth inhibition of the cells. We found that atRA treated cells showed obvious apoptosis. Then, it was postulated that the enhanced content of integrin alpha5beta1 in the absence of ligation with fibronectin (Fn) would stop transducing survival signals, and lead to decreased cell growth and apoptosis. To elucidate this hypothesis, we cultured the atRA treated cell in L-poly-lysine-coated and Fn-coated flask, respectively. The results indicated that Fn binding prevented the cells from apoptosis induced by atRA, in contrast to L-poly-lysine binding. When the transfectant with enhanced expression of integrin alpha5beta1 at the same level of atRA treated cell was cultured in L-poly-lysine-coated flask, apoptosis was triggered. However, apoptotic cell was not detected when those cells were cultured in Fn-coated flask. Meanwhile, culturing the transfectant in the antibody (against integrin alpha5 subunit)-coated flask induced 18.33% of the cells into apoptosis, which is far more than the control group. Our study suggests that increased expression of integrin alpha5beta1 on the surface of SMMC 7721 hepatocarcinoma cell treated by atRA, when unbound to Fn, would stop transducing survival signals to lead to "anoikis", and can be reverted by the interaction of integrin alpha5beta1 with Fn.

Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice

Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.

Analysis of patterns of twist angles in DNA double helix

We have analysed theoretically the patterns of twist angles of B-DNA by the Tung-Harvey model mainly. It is shown that for a sequence of twist angles a smaller twist angle tends to follow a larger one and vice versa. Therefore the sequence of twist angles always takes a gentle zig-zag form. For simplicity we convert the sequence of twist angles to a symbolic sequence consisting of L and S, where L or S represents a large or a small angle, respectively. The -10 and -35 regions of 112 well-defined promoters for E. coli RNA polymerase, which were compiled by Hawley and McClure, have been analysed in terms of LS sequences in detail. The results shows that the number of LS sequences for promoters is considerably limited and the promoter mutations do not change the patterns of LS sequences in most cases. Several new ideas, which are believed to be useful in the further study, have been presented.

Analysis of sequences of twist angles in DNA double helix

By assuming that the realistic DNA chains are random sequence of bases and using the Tung-Harvey formula for the prediction of twist angles, it is shown that the mean value of the sequence of twist angles is almost sequence-independent. In general the variance for the A, T-rich sequence is larger than that of G, C-rich sequence. There exists an upper bound for the variance of all possible sequences, i.e., the variance is not greater than 27 deg2. It is pointed out that the large conformational deviation from ideal DNA is an important factor for the recognition of DNA with protein/enzyme.

[Protective effects of an ethanolic extract and essential oil of Curcuma kwangsinensis S. against experimental liver lesions in mice]

The ethanolic extract and the essential oil of Curcuma kwangsinensis were found to be effective in lowering the elevated SGPT induced by CCl4, TAA and BSP retention. Histological examination showed that hepatic damages of the extract-and oil-pretreated mice were less than those of the CCl4 control group. The ethanolic extract helped to shorten sodium pentobarbital sleeping time in both normal and CCl4 intoxicated mice. In addition, the essential oil exhibited an inhibitory effect on triglyceride accumulation in mice. The toxicity of the extract and the oil was found to be low: oral LD50 was 86.8 +/- 12g crude drug/kg (ethanolic extract) and 1.10 +/- 0.08g/kg (essential oil).