SARS-CoV-2 spike-reactive naïve B cells and pre-existing memory B cells contribute to antibody responses in unexposed individuals after vaccination

Introduction

Since December 2019, the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) has presented considerable public health challenges. Multiple vaccines have been used to induce neutralizing antibodies (nAbs) and memory B-cell responses against the viral spike (S) glycoprotein, and many essential epitopes have been defined. Previous reports have identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike-reactive naïve B cells and preexisting memory B cells in unexposed individuals. However, the role of these spike-reactive B cells in vaccine-induced immunity remains unknown.

Methods

To elucidate the characteristics of preexisting SARS-CoV-2 S-reactive B cells as well as their maturation after antigen encounter, we assessed the relationship of spike-reactive B cells before and after vaccination in unexposed human individuals. We further characterized the sequence identity, targeting domain, broad-spectrum binding activity and neutralizing activity of these SARS-CoV-2 S-reactive B cells by isolating monoclonal antibodies (mAbs) from these B cells.

Results

The frequencies of both spike-reactive naïve B cells and preexisting memory B cells before vaccination correlated with the frequencies of spike-reactive memory B cells after vaccination. Isolated mAbs from spike-reactive naïve B cells before vaccination had fewer somatic hypermutations (SHMs) than mAbs isolated from spike-reactive memory B cells before and after vaccination, but bound SARS-CoV-2 spike in vitro. Intriguingly, these germline-like mAbs possessed broad binding profiles for SARS-CoV-2 and its variants, although with low or no neutralizing capacity. According to tracking of the evolution of IGHV4-4/IGKV3-20 lineage antibodies from a single donor, the lineage underwent SHMs and developed increased binding activity after vaccination.

Discussion

Our findings suggest that spike-reactive naïve B cells can be expanded and matured by vaccination and cocontribute to vaccine-elicited antibody responses with preexisting memory B cells. Selectively and precisely targeting spike-reactive B cells by rational antigen design may provide a novel strategy for next-generation SARS-CoV-2 vaccine development.

TREG cells and CXCR3+ circulating TFH cells concordantly shape the neutralizing antibody responses in individuals who have recovered from mild COVID-19

Regulatory T (TREG) cells are involved in the antiviral immune response in patients with COVID-19; however, whether TREG cells are involved in the neutralizing antibody (nAb) response remains unclear. Here, we found that individuals who recovered from mild but not severe COVID-19 had significantly greater frequencies of TREG cells and lower frequencies of CXCR3+ circulating TFH (cTFH) cells than healthy controls. Furthermore, TREG and CXCR3+ cTFH cells were negatively and positively correlated with the nAb responses, respectively, and TREG cells was inversely associated with CXCR3+ cTFH cells in individuals who recovered from mild COVID-19 but not in those with severe disease. Mechanistically, TREG cells inhibited memory B-cell differentiation and antibody production by limiting the activation and proliferation of cTFH cells, especially CXCR3+ cTFH cells, and functional molecule expression. This study provides novel insight showing that mild COVID-19 elicits a concerted nAb responses which are shaped by both TREG and TFH cells.

SARS-CoV-2 spike-specific TFH cells exhibit unique responses in infected and vaccinated individuals

Long-term humoral immunity to SARS-CoV-2 is essential for preventing reinfection. The production of neutralizing antibody (nAb) and B cell differentiation are tightly regulated by T follicular help (TFH) cells. However, the longevity and functional role of TFH cell subsets in COVID-19 convalescents and vaccine recipients remain poorly defined. Here, we show that SARS-CoV-2 infection and inactivated vaccine elicited both spike-specific CXCR3+ TFH cell and CXCR3- TFH cell responses, which showed distinct response patterns. Spike-specific CXCR3+ TFH cells exhibit a dominant and more durable response than CXCR3- TFH cells that positively correlated with antibody responses. A third booster dose preferentially expands the spike-specific CXCR3+ TFH cell subset induced by two doses of inactivated vaccine, contributing to antibody maturation and potency. Functionally, spike-specific CXCR3+ TFH cells have a greater ability to induce spike-specific antibody secreting cells (ASCs) differentiation compared to spike-specific CXCR3- TFH cells. In conclusion, the persistent and functional role of spike-specific CXCR3+ TFH cells following SARS-CoV-2 infection and vaccination may play an important role in antibody maintenance and recall response, thereby conferring long-term protection. The findings from this study will inform the development of SARS-CoV-2 vaccines aiming to induce long-term protective immune memory.

[Proposal and thoughts on establishing and improving multi-level dental insurance in China]

Oral diseases are highly prevalent in China, while oral health services are generally underutilized and public health resources are wasted. Lacking oral insurance may be one of the leading causes. The basic medical insurance of China does not cover dental care in most cities, which is worthy to further discuss. To better understand the experience of dental insurance from international dental care practice, the dental coverage scope, content, co-pay ratio, and effects of oral insurance on oral health improvement from the abroad countries with typical health insurance systems were summarized by using scoping review. Then, we discussed the coverage scope for dental health of basic medical insurance and private insurance in China. We also analyzed the current issues of dental care coverage and cost-share. At last, we proposed thoughts and suggestions to establish and improve a multi-level oral health insurance system with Chinese characteristics under the basic medical insurance frame. In particular, we gave suggestions on increasing the coverage for high dental care xpenditure by ebasic medical insurance, supplying children and teenagers with preventive dental care, and encouraging private insurance companies to cover dental care expenditure.

Acrylamide-induced meiotic arrest of spermatocytes in adolescent mice by triggering excessive DNA strand breaks: Potential therapeutic effects of resveratrol

Background: Baked carbohydrate-rich foods are the main source of acrylamide (AA) in the general population and are widely consumed by teenagers. Considering the crucial development of the reproductive system during puberty, the health risks posed by AA in adolescent males have raised public concern.Methods: In this study, we exposed 3-week-old male pubertal mice to AA for 4 weeks to evaluate its effect on spermatogenesis using computer-assisted sperm analysis (CASA) and historical analysis. Flow cytometric analysis and meiocyte spreading assay were conducted to assess meiosis in mice. The expression of meiosis-related proteins and double-strand break (DSB) proteins were evaluated by immunoblot analyses. Additionally, isolated spermatocytes were used to explore the role of resveratrol in AA-induced damages of meiosis.Results: Our results showed that AA decreased the testicular and epididymal indexes, reduced sperm count and motility, and induced morphological disruption of the testes in pubertal mice. Subsequent meiotic analysis revealed that AA increased the proportion of 4C spermatocytes and decreased the proportion of 1C spermatids. The expression levels of meiosis-related proteins (SYCP3, Cyclin A1 and CDK2) were downregulated, and signaling proteins (γH2AX, p-CHK2 and p-ATM) expression levels were upregulated in AA-treated mice testes. Similar expression patterns were observed in primary spermatocytes treated with AA and these effects were reversed significantly by resveratrol.Conclusions: Our results indicate that AA induces meiotic arrest via persistent activation of DSBs, which may contribute to AA-compromised spermatogenesis. Resveratrol could serve as a potential therapeutic agent against AA-induced meiotic toxicity. These data highlight the importance of natural product supplementation for treating AA-related reproductive toxicity.

Monoclonal antibodies constructed from COVID-19 convalescent memory B cells exhibit potent binding activity to MERS-CoV spike S2 subunit and other human coronaviruses

Introduction

The Middle East respiratory syndrome coronavirus (MERS-CoV) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are two highly contagious coronaviruses causing MERS and COVID-19, respectively, without an effective antiviral drug and a long-lasting vaccine. Approaches for diagnosis, therapeutics, prevention, etc., particularly for SARS-CoV-2 that is continually spreading and evolving, are urgently needed. Our previous study discovered that >60% of sera from convalescent COVID-19 individuals, but <8% from general population, showed binding activity against the MERS-CoV spike protein, indicating that SARS-CoV-2 infection boosted antibodies cross-reactive with MERS-CoV.

Methods

To generate antibodies specific to both SARS-CoV-2 and MERS-CoV, here we screened 60 COVID-19 convalescent sera against MERS-CoV spike extracellular domain and S1 and S2 subunits. We constructed and characterized monoclonal antibodies (mAbs) from COVID-19 convalescent memory B cells and examined their binding and neutralizing activities against human coronaviruses.

Results and Discussion

Of 60 convalescent serum samples, 34 showed binding activity against MERS-CoV S2, with endpoint titers positively correlated with the titers to SARS-CoV-2 S2. By sorting single memory B cells from COVID-19 convalescents, we constructed 38 mAbs and found that 11 mAbs showed binding activity with MERS-CoV S2, of which 9 mAbs showed potent cross-reactivity with all or a proportion of spike proteins of alphacoronaviruses (229E and NL63) and betacoronaviruses (SARS-CoV-1, SARS-CoV-2, OC43, and HKU1). Moreover, 5 mAbs also showed weak neutralization efficiency against MERS-CoV spike pseudovirus. Epitope analysis revealed that 3 and 8 mAbs bound to linear and conformational epitopes in MERS-CoV S2, respectively. In summary, we have constructed a panel of antibodies with broad-spectrum reactivity against all seven human coronaviruses, thus facilitating the development of diagnosis methods and vaccine design for multiple coronaviruses.

Reduced sensitivity of the SARS-CoV-2 Lambda variant to monoclonal antibodies and neutralizing antibodies induced by infection and vaccination

Severe acute respiratory syndrome coronavirus 2 variants have continued to emerge in diverse geographic locations with a temporal distribution. The Lambda variant containing multiple mutations in the spike protein, has thus far appeared mainly in South America. The variant harbours two mutations in the receptor binding domain, L452Q and F490S, which may change its infectivity and antigenicity to neutralizing antibodies. In this study, we constructed 10 pseudoviruses to study the Lambda variant and each individual amino acid mutation's effect on viral function, and used eight cell lines to study variant infectivity. In total, 12 monoclonal antibodies, 14 convalescent sera, and 23 immunized sera induced by mRNA vaccines, inactivated vaccine, and adenovirus type 5 vector vaccine were used to study the antigenicity of the Lambda variant. We found that compared with the D614G reference strain, Lambda demonstrated enhanced infectivity of Calu-3 and LLC-MK2 cells by 3.3-fold and 1.6-fold, respectively. Notably, the sensitivity of the Lambda variant to 5 of 12 neutralizing monoclonal antibodies, 9G11, AM180, R126, X593, and AbG3, was substantially diminished. Furthermore, convalescent- and vaccine-immunized sera showed on average 1.3-2.5-fold lower neutralizing titres against the Lambda variant. Single mutation analysis revealed that this reduction in neutralization was caused by L452Q and F490S mutations. Collectively, the reduced neutralization ability of the Lambda variant suggests that the efficacy of monoclonal antibodies and vaccines may be compromised during the current pandemic.

Resectability of bilobar liver tumours after simultaneous portal and hepatic vein embolization versus portal vein embolization alone: meta-analysis

BACKGROUND

Many patients with bi-lobar liver tumours are not eligible for liver resection due to an insufficient future liver remnant (FLR). To reduce the risk of posthepatectomy liver failure and the primary cause of death, regenerative procedures intent to increase the FLR before surgery. The aim of this systematic review is to provide an overview of the available literature and outcomes on the effectiveness of simultaneous portal and hepatic vein embolization (PVE/HVE) versus portal vein embolization (PVE) alone.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, and Embase up to September 2022. The primary outcome was resectability and the secondary outcome was the FLR volume increase.

RESULTS

Eight studies comparing PVE/HVE with PVE and six retrospective PVE/HVE case series were included. Pooled resectability within the comparative studies was 75 per cent in the PVE group (n = 252) versus 87 per cent in the PVE/HVE group (n = 166, OR 1.92 (95% c.i., 1.13-3.25)) favouring PVE/HVE (P = 0.015). After PVE, FLR hypertrophy between 12 per cent and 48 per cent (after a median of 21-30 days) was observed, whereas growth between 36 per cent and 67 per cent was reported after PVE/HVE (after a median of 17-31 days). In the comparative studies, 90-day primary cause of death was similar between groups (2.5 per cent after PVE versus 2.2 per cent after PVE/HVE), but a higher 90-day primary cause of death was reported in single-arm PVE/HVE cohort studies (6.9 per cent, 12 of 175 patients).

CONCLUSION

Based on moderate/weak evidence, PVE/HVE seems to increase resectability of bi-lobar liver tumours with a comparable safety profile. Additionally, PVE/HVE resulted in faster and more pronounced hypertrophy compared with PVE alone.

Dragon 1 Protocol Manuscript: Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy

STUDY PURPOSE

The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases.

METHODS

The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection.

RESULTS

Not applicable.

CONCLUSION

DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04272931 (February 17, 2020). Toestingonline.nl: NL71535.068.19 (September 20, 2019).

[Prevalence and frequencies of human papilloma virus types in adenocarcinoma in situ of the uterine cervix]

Objective: To examine the prevalence and frequencies of human papillomavirus (HPV) genotypes in cervical adenocarcinoma in situ (AIS). Methods: The cases of cervical AIS with concurrent tests of cytology and HPV typing from January 2007 to February 2020 in the Obstetrics and Gynecology Hospital of Fudan University were collected and analyzed. Results: A total of 478 cases of cervical AIS were obtained. The average age of the patients was 39.4 years (range, 19-81 years). The largest age group was 30-39 years (44.8%), followed by 40-49 years (34.7%). Among the 478 patients, 355 underwent high-risk HPV (hrHPV) testing and had a hrHPV-positive rate of 93.8%. Of the 355 patients, 277 also underwent HPV typing and were mostly positive for either or both HPV16 and HPV18 (93.1%), with 55.6% positive for HPV18 and 48.7% positive for HPV16. Among the 478 cases, 266 cases (55.6%) were diagnosed with both AIS and squamous intraepithelial lesion (SIL), while 212 cases (44.4%) were diagnosed with only AIS. Patients infected with HPV16 in the AIS and SIL group significantly outnumbered those in the AIS alone group (P<0.05). Moreover, the rate of positive cytology was 55.9% (167/299 cases), while that of negative cytology was 44.1% (132/299). Among the 109 patients with negative cytology results and co-tested hrHPV, there were 101 HPV-positive cases (92.7%), of which 88 cases were subject to HPV typing and showed an HPV16/18 positive rate of 94.3% (83/88 cases). Conclusions: The combination of HPV typing and cytological screening can maximize the detection rate of cervical AIS, and should continue to be utilized, ideally on a larger scale, in the future.

The antigenicity of SARS-CoV-2 Delta variants aggregated 10 high-frequency mutations in RBD has not changed sufficiently to replace the current vaccine strain

Emerging SARS-CoV-2 variants are the most serious problem for COVID-19 prophylaxis and treatment. To determine whether the SARS-CoV-2 vaccine strain should be updated following variant emergence like seasonal flu vaccine, the changed degree on antigenicity of SARS-CoV-2 variants and H3N2 flu vaccine strains was compared. The neutralization activities of Alpha, Beta and Gamma variants' spike protein-immunized sera were analysed against the eight current epidemic variants and 20 possible variants combining the top 10 prevalent RBD mutations based on the Delta variant, which were constructed using pseudotyped viruses. Meanwhile, the neutralization activities of convalescent sera and current inactivated and recombinant protein vaccine-elicited sera were also examined against all possible Delta variants. Eight HA protein-expressing DNAs elicited-animal sera were also tested against eight pseudotyped viruses of H3N2 flu vaccine strains from 2011-2019. Our results indicate that the antigenicity changes of possible Delta variants were mostly within four folds, whereas the antigenicity changes among different H3N2 vaccine strains were approximately 10-100-fold. Structural analysis of the antigenic characterization of the SARS-CoV-2 and H3N2 mutations supports the neutralization results. This study indicates that the antigenicity changes of the current SARS-CoV-2 may not be sufficient to require replacement of the current vaccine strain.

Aggregation of high-frequency RBD mutations of SARS-CoV-2 with three VOCs did not cause significant antigenic drift

Variants of SARS‐CoV‐2 continue to emerge, posing great challenges in outbreak prevention and control. It is important to understand in advance the impact of possible variants of concern (VOCs) on infectivity and antigenicity. Here, we constructed one or more of the 15 high‐frequency naturally occurring amino acid changes in the receptor‐binding domain (RBD) of Alpha, Beta, and Gamma variants. A single mutant of A520S, V367F, and S494P in the above three VOCs enhanced infectivity in ACE2‐overexpressing 293T cells of different species, LLC‐MK2 and Vero cells. Aggregation of multiple RBD mutations significantly reduces the infectivity of the possible three VOCs. Regarding neutralization, it is noteworthy that E484K, N501Y, K417N, and N439K predispose to monoclonal antibodies (mAbs) protection failure in the 15 high‐frequency mutations. Most importantly, almost all possible VOCs (single RBD mutation or aggregation of multiple mutations) showed no more than a fourfold decrease in neutralizing activity with convalescent sera, vaccine sera, and immune sera of guinea pigs with different immunogens, and no significant antigenic drift was formed. In conclusion, our pseudovirus results could reduce the concern that the aggregation of multiple high‐frequency mutations in the RBD of the spike protein of the three VOCs would lead to severe antigenic drift, and this would provide value for vaccine development strategies.

Infectivity increased by adding three VOCs of V367F, S494P, or A520S.

The infectivity of the three VOCs with multiple high‐frequency mutations decreased.

Almost all of the possible variants of the three VOCs did not show severe antigenic drift.

The significant immune escape of pseudotyped SARS-CoV-2 variant Omicron

The emergence of Omicron/BA.1 has brought new challenges to fight against SARS-CoV-2. A large number of mutations in the Spike protein suggest that its susceptibility to immune protection elicited by the existing COVID-19 infection and vaccines may be altered. In this study, we constructed the pseudotyped SARS-CoV-2 variant Omicron. The sensitivity of 28 serum samples from COVID-19 convalescent patients infected with SARS-CoV-2 original strain was tested against pseudotyped Omicron as well as the other variants of concern (VOCs, Alpha, Beta, Gamma, Delta) and variants of interest (VOIs, Lambda, Mu). Our results indicated that the mean neutralization ED50 of these sera against Omicron decreased to 66, which is about 8.4-folds compared to the D614G reference strain (ED50 = 556), whereas the neutralization activity of other VOC and VOI pseudotyped viruses decreased only about 1.2-4.5-folds. The finding from our in vitro assay suggest that Omicron variant may lead to more significant escape from immune protection elicited by previous SARS-CoV-2 infection and perhaps even by existing COVID-19 vaccines.

The Antigenicity of Epidemic SARS-CoV-2 Variants in the United Kingdom

To determine whether the neutralization activity of monoclonal antibodies, convalescent sera and vaccine-elicited sera was affected by the top five epidemic SARS-CoV-2 variants in the UK, including D614G+L18F+A222V, D614G+A222V, D614G+S477N, VOC-202012/01(B.1.1.7) and D614G+69-70del+N439K, a pseudovirus-neutralization assay was performed to evaluate the relative neutralization titers against the five SARS-CoV-2 variants and 12 single deconvolution mutants based on the variants. In this study, 18 monoclonal antibodies, 10 sera from convalescent COVID-19 patients, 10 inactivated-virus vaccine-elicited sera, 14 mRNA vaccine-elicited sera, nine RBD-immunized mouse sera, four RBD-immunized horse sera, and four spike-encoding DNA-immunized guinea pig sera were tested and analyzed. The N501Y, N439K, and S477N mutations caused immune escape from nine of 18 mAbs. However, the convalescent sera, inactivated virus vaccine-elicited sera, mRNA vaccine-elicited sera, spike DNA-elicited sera, and recombinant RBD protein-elicited sera could still neutralize these variants (within three-fold changes compared to the reference D614G variant). The neutralizing antibody responses to different types of vaccines were different, whereby the response to inactivated-virus vaccine was similar to the convalescent sera.

SARS-CoV-2 501Y.V2 variants lack higher infectivity but do have immune escape

The 501Y.V2 variants of SARS-CoV-2 containing multiple mutations in spike are now dominant in South Africa and are rapidly spreading to other countries. Here, experiments with 18 pseudotyped viruses showed that the 501Y.V2 variants do not confer increased infectivity in multiple cell types except for murine ACE2-overexpressing cells, where a substantial increase in infectivity was observed. Notably, the susceptibility of the 501Y.V2 variants to 12 of 17 neutralizing monoclonal antibodies was substantially diminished, and the neutralization ability of the sera from convalescent patients and immunized mice was also reduced for these variants. The neutralization resistance was mainly caused by E484K and N501Y mutations in the receptor-binding domain of spike. The enhanced infectivity in murine ACE2-overexpressing cells suggests the possibility of spillover of the 501Y.V2 variants to mice. Moreover, the neutralization resistance we detected for the 501Y.V2 variants suggests the potential for compromised efficacy of monoclonal antibodies and vaccines.

The protective effect of hesperidin against renal ischemia-reperfusion injury involves the TLR-4/NF-κB/iNOS pathway in rats

Renal injury is reported to have a high mortality rate. Additionally, there are several limitations to current conventional treatments that are used to manage it. This study evaluated the protective effect of hesperidin against ischemia/reperfusion (I/R)-induced kidney injury in rats. Renal injury was induced by generating I/R in kidney tissues. Rats were then treated with hesperidin at a dose of 10 or 20 mg/kg intravenously 1 day after surgery for a period of 14 days. The effect of hesperidin on renal function, serum mediators of inflammation, and levels of oxidative stress in renal tissues were observed in rat kidney tissues after I/R-induced kidney injury. Moreover, protein expression and mRNA expression in kidney tissues were determined using Western blotting and RT-PCR. Hematoxylin and eosin (H&E) staining was done for histopathological observation of kidney tissues. The data suggest that the levels of blood urea nitrogen (BUN) and creatinine in the serum of hesperidin-treated rats were lower than in the I/R group. Treatment with hesperidin also ameliorated the altered level of inflammatory mediators and oxidative stress in I/R-induced renal-injured rats. The expression of p-IκBα, caspase-3, NF-κB p65, Toll-like receptor 4 (TLR-4) protein, TLR-4 mRNA, and inducible nitric oxide synthase (iNOS) was significantly reduced in the renal tissues of hesperidin-treated rats. Histopathological findings also revealed that treatment with hesperidin attenuated the renal injury in I/R kidney-injured rats. In conclusion, our results suggest that hesperidin protects against renal injury induced by I/R by involving TLR-4/NF-κB/iNOS signaling.

[Clinical application of single-port inflatable endoscopic nipple sparing mastectomy with immediate reconstruction using prosthesis implantation]

Objective: To examine the clinical application value of single-port inflatable endoscopic nipple sparing mastectomy with immediate reconstruction using prosthesis implantation in the treatment of early breast cancer. Methods: From February 2014 to July 2019, the clinic-pathological data of 34 early breast cancer patients received single-port inflatable endoscopic nipple sparing mastectomy with immediate reconstruction using prosthesis implantation at Department of General Surgery, Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed and followed up. All the patients were female, with an age of 46(11) years (M(Q_R)) (range: 26 to 64 years). The radical cure degree of operation, cosmetic effect after operation were evaluated. The satisfaction to operation and personal quality of life after operation was accessed by BREAST-Q scale. Results: All surgical procedures were successfully completed. The operation time was (313.4±11.7) minutes (range: 200 to 485 minutes). The blooding-liquid was (33.8±3.3) ml (range: 10 to 100 ml). There were 5 cases (14.7%) of nipple areola necrosis after operation, of which 1 patient received taking the prosthesis out because of prosthesis exposure. There was no capsular contracture or postoperative bleeding case. The follow-up time was 35(17) months (range: 12 to 77 months), and there was one case suffering local recurrence and metastasis, and another suffering metastasis. The scores of postoperative breast satisfaction, psychosocial status, chest wall status and sexual health were 78.32±2.57 (range: 55 to 100), 89.12±2.30 (range: 82 to 100), 91.47±1.33 (range: 43 to 100), and 78.50±2.68 (range: 39 to 100). Conclusion: Single-port inflatable endoscopic nipple sparing mastectomy with immediate reconstruction using prosthesis implantation in the treatment of early breast cancer can achieve provided curative and cosmetic effect on patients with breast cancer, with good patients' postoperative quality of life and satisfaction.

Whole genome expression microarray reveals novel roles for Kif4 in monocyte/macrophage cells

OBJECTIVE

Kinesin superfamily member 4 (Kif4), a conventional kinesin, is a microtubule-dependent molecular motor. The active movement of Kif4 participates in several cellular functions, including DNA repair, mitosis, the transport of macromolecules, survival of neurons and even tumorigenesis and progression. However, the role of Kif4 in monocyte/macrophage cells has not been reported. Our work aimed to increase understanding and further investigations of Kif4 in monocyte/macrophage cells.

MATERIALS AND METHODS

RAW264.7 cells were transfected with Kif4 small interfering RNA (siRNA), and whole genome expression microarray analysis was employed to analyze gene expression after cells treatment with or without Kif4 siRNA.

RESULTS

Our data found multiple differentially expressed genes which were enriched in the top 5 biological processes about innate immune response, immune response, response to interferon-beta, immune system process and cellular response to interferon-beta. 23 most significant pathways had been identified and enriched pathways indicated enrichment in peroxisome, lysosome, fatty acid metabolism, cell adhesion molecules and so on.

CONCLUSIONS

Our work may help understand the roles of Kif4 in monocyte/macrophage cells and would give useful information on basic research and the function of monocyte/macrophage cells.

Spike-specific circulating T follicular helper cell and cross-neutralizing antibody responses in COVID-19-convalescent individuals

Coronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)^1-3 and individuals with COVID-19 have symptoms that can be asymptomatic, mild, moderate or severe^4,5. In the early phase of infection, T- and B-cell counts are substantially decreased^6,7; however, IgM^8-11 and IgG^12-14 are detectable within 14 d after symptom onset. In COVID-19-convalescent individuals, spike-specific neutralizing antibodies are variable^3,15,16. No specific drug or vaccine is available for COVID-19 at the time of writing; however, patients benefit from treatment with serum from COVID-19-convalescent individuals^17,18. Nevertheless, antibody responses and cross-reactivity with other coronaviruses in COVID-19-convalescent individuals are largely unknown. Here, we show that the majority of COVID-19-convalescent individuals maintained SARS-CoV-2 spike S1- and S2-specific antibodies with neutralizing activity against the SARS-CoV-2 pseudotyped virus, and that some of the antibodies cross-neutralized SARS-CoV, Middle East respiratory syndrome coronavirus or both pseudotyped viruses. Convalescent individuals who experienced severe COVID-19 showed higher neutralizing antibody titres, a faster increase in lymphocyte counts and a higher frequency of CXCR3⁺ T follicular help (T_FH) cells compared with COVID-19-convalescent individuals who experienced non-severe disease. Circulating T_FH cells were spike specific and functional, and the frequencies of CXCR3⁺ T_FH cells were positively associated with neutralizing antibody titres in COVID-19-convalescent individuals. No individuals had detectable autoantibodies. These findings provide insights into neutralizing antibody responses in COVID-19-convalescent individuals and facilitate the treatment and vaccine development for SARS-CoV-2 infection.

RNA interference-mediated knockdown of the transcription factor Krüppel homologue 1 suppresses vitellogenesis in Chilo suppressalis

Vitellogenesis in holometabolous insects involves the production and secretion of vitellogenin (Vg) and other yolk protein precursors in developing oocyte by the fat body, all of which is predominantly orchestrated by juvenile hormone (JH). Krüppel homologue 1 (Kr-h1) is a zinc finger transcription factor that has been demonstrated to be a JH-early inducible gene and to contribute to reproduction. However, the exact molecular function of Kr-h1 in insect reproduction is poorly understood. In the current study, we used the notorious pest Chilo suppressalis as a model system to investigate the role of Kr-h1 in female reproduction. Cloning and sequencing C. suppressalis Kr-h1 revealed that it shares high identity with its homologues from other lepidopteran insects. Moreover, RNA interference-mediated knockdown of CsKr-h1 substantially reduced the transcription of Vg in the fat body, dramatically decreased yolk protein deposition and also impaired oocyte maturation and ovarian development, indicating that Kr-h1 is indispensable for normal vitellogenesis in C. suppressalis. Based on these results, we conclude that Kr-h1 is crucial to reproduction in insects and that targeting this gene could potentially be a new way to suppress rice pests.

Molecular cloning, characterisation, and expression analysis of adipocyte fatty acid binding protein gene in Xupu goose (Anser cygnoides domesticus)

1. Adipocyte fatty acid binding protein (A-FABP) plays a key role in fatty acid uptake and intracellular transport. The objective of the present study was to identify and characterise the A-FABP gene in Xupu goose.2. The full-length cDNA of goose A-FABP gene was cloned from the liver tissue using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The distribution of the goose A-FABP in different tissues was determined by quantitative real-time PCR (qRT-PCR).3. The results showed that the full-length cDNA sequence of goose A-FABP was 657 bp, containing a 5'-UTR of 52 bp, a 3'-UTR of 206 bp and an open reading frame (ORF) of 399 bp, which encoded a polypeptide of 132 amino acids (AA).4. The AA sequence of goose A-FABP showed 76.52%, 75.00%, 93.18% and 99.24% identities with previously described homologues from humans (Homo sapiens), mouse (Mus musculus), chicken (Gallus gallus), and duck (Anas platyrhynchos), respectively, and phylogenetic analysis revealed a close relationship among them. The transcript of Xupu goose A-FABP was ubiquitously expressed in all tested tissues, and showed a high-level expression in abdominal fat, sebum and liver.5. A significant positive correlation was identified between A-FABP mRNA abundance in the three adipose tissues and liver weight, ratio of liver to body weight, TG content, and VLDL concentration in the plasma of Xupu goose. A significant negative correlation was observed between the mRNA level of A-FABP and HDL concentration in the plasma of Xupu goose.6. These findings provide a foundation for further research on the function and mechanism of A-FABP in the fat deposition process.

Early life famine exposure to the Great Chinese Famine in 1959-1961 and subsequent pregnancy loss: a population-based study

OBJECTIVE

To explore the relation between famine exposure in early life and subsequent pregnancy loss, including stillbirth, and spontaneous abortion in adulthood.

DESIGN

A population-based, partly ecological study.

SETTING AND POPULATION

Individual data of 58 601 females born around the time of the Great Chinese Famine in 1959-1961.

METHODS

Associations between the famine exposure in early life and pregnancy loss (stillbirth and spontaneous abortion) in adulthood were analysed using negative binomial regression, with the non-exposure group as reference, adjusting for region, highest education, monthly income, alcohol consumption, tobacco use, body mass index in 25-year-olds and metabolic equivalent. Further analyses were stratified by rural versus urban region.

MAIN OUTCOME MEASURES

Continuous variables of times of stillbirths and spontaneous abortions were used according to the individual self-reported reproductive history.

RESULTS

No association was found between famine exposure and spontaneous abortion. In contrast, females experiencing the famine during their prenatal period (incidence rate ratio = 1.15, 95% CI 1.00-1.33) or infant period (incidence rate ratio = 1.27, 95% CI 1.12-1.44) were more likely to report stillbirth in later adult life. Such an association appeared stronger in women living in rural regions.

CONCLUSIONS

Early life exposure of famine was associated with an increased risk of stillbirth but not spontaneous abortion in adulthood. The strength of such an association appeared stronger in rural areas. Given the high potential for unmeasured confounding, these associations must be interpreted with caution. Regarding the potential implication that undernutrition in the fetal period is related to reproductive outcome in adulthood, fetal nutritional supply may play an important role in human reproduction.

TWEETABLE ABSTRACT

Exposure to famine in early life was associated with increased pregnancy loss in adulthood.

HBV coinfection with HCV alters circulating Tfh cell distribution and impairs HCV neutralizing antibody responses

Hepatitis C virus (HCV) and hepatitis B virus (HBV) coinfection reciprocally influences viral replication and host defence responses. This study aimed to investigate the impact of HBV coinfection on circulating T follicular helper cell (cTfh) distribution and the HCV neutralizing antibody (nAb) response. HCV neutralizing antibody responses were measured in individuals with HCV monoinfection (n = 83) and HBV/HCV coinfection (n = 78) using the HCV pseudoparticle neutralization assay. The frequencies of cTfh cells and their subsets in HCV monoinfection (n = 34) and HBV/HCV coinfection (n = 30) were analysed by flow cytometry. The correlations of clinical parameters, cTfh cells and neutralizing antibody responses were analysed. Compared with HCV monoinfection, the HBV coinfection group showed significantly lower HCV neutralizing antibody responses (P < 0.001) and a decreased frequency of circulating Th1-like Tfh cells (Tfh1) (P = 0.004). In HCV monoinfection, the frequency of the Tfh1 subset was positively correlated with HCV neutralizing antibody responses (R = 0.378, P = 0.03), but this correlation was lost under HBV/HCV coinfection (R = 0.115, P = 0.551). In contrast, the frequency of circulating Th2-like Tfh cells (Tfh2) was negatively correlated with the HCV neutralizing antibody responses (R = 0.404, P = 0.003). Further analysis showed that HBV coinfection enhanced the Tfh2 subset composition within cTfh cells (P < 0.001), which was associated with serum HBsAg in HBV/HCV coinfection (R = 0.521, P = 0.003). As expected, HBsAg also exhibited an inverse association with HCV neutralizing antibody responses in HBV/HCV coinfection (R = 0.59, P < 0.001). In contrast to HCV monoinfection, HBV/HCV coinfection leads to altered cTfh cell distribution and impaired HCV neutralizing antibody responses, which are associated with HBsAg. These findings will be helpful for better understanding the immunopathogenesis of HBV/HCV coinfection.

Circulating CXCR3+ Tfh cells positively correlate with neutralizing antibody responses in HCV-infected patients

Circulating T follicular helper (cTfh) cells have been identified as counterparts of germinal center Tfh (GC Tfh) cells in humans and can support T-dependent B cell maturation and antibody production in vitro. However, the role of cTfh cells in neutralizing antibody (nAb) responses in HCV infection remains unclear. Here, we characterized the phenotype and function of cTfh cells and demonstrated the associations of cTfh cells and their subsets with nAb responses in HCV infection. A total of 38 HCV-infected individuals and 28 healthy controls were enrolled from a pool of injection drug users. The frequency and function of blood Tfh cells were analyzed by flow cytometry. The titers and breadths of serum nAbs were measured using HCV pseudo-particle neutralization assays. Herein, we report several key observations. First, HCV infection skewed cTfh toward CXCR3⁺ cTfh cell differentiation. Second, the frequency of CXCR3⁺ cTfh cells positively correlated with HCV nAb titers and breadths. Third, CXCR3⁺ cTfh cells showed higher expression of Tfh-associated molecules (PD-1, ICOS, IL-21, Bcl-6) compared with CXCR3⁻ cTfh cells from individuals with HCV infection. Coculture of cTfh cells and autologous memory B cells in vitro indicated that CXCR3⁺ cTfh cells show a superior ability to support HCV E2-specific B cell expansion compared with CXCR3⁻ cTfh cells from individuals with HCV infection. HCV infection skews cTfh cells toward CXCR3-biased Tfh cell differentiation, which positively correlates with the magnitude and breadth of the HCV nAb response. It is our hope that these findings will provide insights for the rational design of a nAb-based HCV vaccine.

Elevated LAG-3 on CD4+ T cells negatively correlates with neutralizing antibody response during HCV infection

Lymphocyte activation gene-3 (LAG-3), an inhibitory molecule, which has been shown co-expressed with multiple inhibitory receptors on CD8⁺ T and natural killer (NK) cells and negatively regulates T and NK cell responses during hepatitis C virus (HCV) infection. However, whether LAG-3 is involved in the regulation of the antibody response remains unclear. This study aims to investigate the relationship of LAG-3 with neutralizing antibody (nAb) response during HCV infection. A total of 66 HCV-infected individuals and 36 sex- and age-matched healthy controls from a population of intravenous drug users were recruited. Circulating follicular helper T (cTfh) cells and LAG-3-expressing CD4⁺ T cells, type 1 regulatory T (Tr1) cells, and regulatory T (Treg) cells were characterized by flow cytometry. Serum nAb response of HCV-infected individuals was determined using pseudoparticle neutralization assays. We found that HCV infection enhanced LAG-3 expression on CD4⁺ T cells and exhibited regulatory T cell-like phenotype and inversely associated with the HCV nAb response. Further analysis showed that frequency of CXCR3⁺ cTfh cells positively correlated with nAb response, however LAG-3⁺ CD4⁺ T cells inversely associated with CXCR3⁺ cTfh cells. This study observed that LAG-3⁺ CD4⁺ T cells exhibit a regulatory cell phenotype and negatively associate with the HCV nAb response, implying that LAG-3 may be involved in the negative regulation of humoral immunity during HCV infection.

Infection of human pegivirus 2 (HPgV-2) is associated with hepatitis C virus but not hepatitis B virus infection in people who inject drugs

We evaluated the association between human pegivirus-2 (HPgV-2) infection and hepatitis C virus (HCV)/hepatitis B virus (HBV) co-infection in 745 plasma samples collected from HCV-positive but human immunodeficiency virus type one (HIV-1)-negative people who inject drugs in Hunan, China. The prevalence of anti-HPgV-2 was 4.43  % (33/745) and, within this, the HCV 6a genotype showed significantly higher prevalence as compared with the HCV non-6a genotypes, 6.29  % (18/286) vs. 1.69  % (4/236), respectively (P=0.009). HPgV-2 RNA was detected in 2.15  % (16/745), and was not significantly different between the HCV 6a and non-6a genotypes, 2.45  % (7/286) vs. 2.54  % (6/236), respectively (P =0.945). HBV single infection did not increase the risk of HPgV-2 infection. Compared with HCV single infection, HCV/HBV co-infection increased the risk of HPgV-2 infection by about three-fold: odds ratio (OR)=3.24 [95  % confidence interval (CI) 1.34-7.82, P=0.014] according to anti-HPgV-2 positivity or OR=3.51 (95  % CI 1.15-10.74, P=0.051) according to HPgV-2 viraemia. HPgV-2 infection did not increase the levels of liver-specific enzymes. Our study provides new findings regarding the association between HPgV-2 and HCV genotypes as well as HCV/HBV co-infection.

The E3 ubiquitin ligase Cbl-b inhibits tumor growth in multidrug-resistant gastric and breast cancer cells

Most receptor tyrosine kinases (RTKs) contribute to tumor growth, and their ubiquitination and degradation is related to the inhibition of tumor growth. Our previous study showed that the ubiquitin ligase Cbl-b was expressed at low levels in multidrug-resistant (MDR) gastric cancer cells compared with their parental cells. However, whether enhancement of Cbl-b expression in MDR cancer cells could prevent tumor proliferation via ubiquitination and degradation of RTK remains unclear. In the present study, Cbl-b overexpression reduced cell proliferation in MDR gastric and breast cancer cells, and effectively inhibited tumor growth in vivo. Additionally, Cbl-b overexpression reduced the total protein level of insulin-like growth factor 1 (IGF-1R), an important member of the RTK family. Moreover, Cbl-b overexpression promoted interaction of Cbl-b with IGF-1R, and induced ubiquitination and degradation of IGF-1R and inactivation of the IGF-1R pathway. These results suggest that the ubiquitin ligase Cbl-b inhibited tumor growth via ubiquitination and degradation of IGF-1R in MDR gastric and breast cancer cells.

[Effect of death decoy receptor 3 on prognosis of breast cancer and function of breast cancer cells in vitro]

Objective: To study the effect of death decoy receptor 3 on the prognosis of breast cancer and the invasive function of breast cancer cells in vitro. Methods: Expression of DcR3 were assessed qualitatively by Q-PCR to analyze the correlation in 115 mammary tissue samples with a 10-year median follow-up. The expression of DcR3 was examined in MCF7 and MDA-MB-231 cell lines using immunocytochemical staining and RT-PCR. DcR3 knock-down cell sub-lines were constructed. The effects of reduced DcR3 expression were observed by establishing invasion and migration models. Results: Patients were divided into the good prognosis group (n=81) and the poor prognosis group (n=26). The expression of DcR3 in the poor prognosis group (133 350+49 646 copies/50 ng RNA)was significantly higher than that in the good prognosis group (5 393+1 428 copies/50 ng RNA, P=0.020). DcR3 transcripts were found to be increased significantly in grade 2 cancers compared to well differentiated grade 1(82 844±34 068 copies/50 ng RNA, n=39,) vs (5 371±3 500 copies/50 ng RNA, n=20, P=0.029).The DcR3 gene of MCF7 cell line and MDA-MB-231 cell line were successfully knocked out and verified that DcR3 knockout. And the invasion and migration of MCF7 cells were inhibited (P=0.009, P=0.001). However, no significant difference was found in these two aspects of the MDA-MB-231 cell line (P=0.475, P=0.102). Conclusion: DcR3 promotes the capacity of invasion of breast cancer cells and plays an important role in the metastasis of breast cancer. DcR3 detection is helpful to the judgment about prognosis of breast cancer.

MiR-99a-5p regulates proliferation, migration and invasion abilities of human oral carcinoma cells by targeting NOX4

Previous research has showed that miR-99a-5p was a tumor suppressor. The aim of our study was to explore the effect of miR-99a-5p on the vitality and proliferation, migration together with the invasion of oral tumor cells via inhibiting the expression of NOX4. QRT-PCR and Western blot were applied to examine the expression level of miR-99a-5p and NOX4 in human oral tumorous and adjacent tissues. Dual luciferase reporter gene assay was applied to confirm that miR-99a-5p negatively regulated directly on NOX4 in TSCC1 cells. Cell transfection and lentiviral vectors were used to up-regulate expression of miR-99a-5p and NOX4, respectively. Cell proliferation, cell cycle, apoptosis and invasion along with the migration in different groups were assessed using MTT assay, colony formation assay, the flow cytometry, transwell assay and the wound healing assay, respectively. MiR-99a-5p was under-expressed in human oral tumor, while NOX4 was over-expressed. There was a negative relationship between miR-99a-5p and NOX4. Up-regulating miR-99a-5p or down-regulating NOX4 suppressed the vitality, proliferation, migration together with invasion of TSCC1 cells. MiR-99a-5p affected the vitality and proliferation, migration together with the invasion of oral tumor cells through targeting NOX4.

Regulatory T cells are an important prognostic factor in breast cancer: a systematic review and meta-analysis

The clinical relevance of regulatory T cell (Treg) infiltration in breast cancer (BC) remains controversial, and no recent meta-analysis has been published on this subject. Our aim was to identify the precise relationship between Tregs and the prognosis and clinic-pathological features of BC. Eligible articles were identified with a MEDLINE database search over a period up to March 2015. Our meta-analysis was performed using STATA software 11.0 and Review Manager 5.3. The correlations between Treg infiltration and clinico-pathological features and BC prognosis were analyzed. Subgroup and sensitivity analyses, as well as meta-regression, were conducted. Eighteen published studies (including 8,562 patients) were eligible. Overall survival (OS) and disease-, recurrence-, and progression-free survival (DFS/RFS/PFS) were correlated with Treg infiltration (OR=2.03 (95% CI, 1.40-2.95; P=0.000) and 1.48 (95% CI, 1.00-2.19; P=0.050), respectively), including 3-, 5-, and 10-year mortality rates. In addition, low Treg infiltration was present in estrogen receptor (ER)-positive tumors (P=0.000), progesterone receptor (PR)-positive tumors (P=0.003), Her2-negative tumors (P=0.000) and histological grade I/II tumors (P=0.001). No publication bias was observed with the exception of OS. Subgroup analysis suggested that the mortality rate of the high Treg infiltration subgroup was increased compared with the low Treg infiltration subgroup among ER-positive patients. Treg infiltration indicated a poorer prognosis for BC and is related to ER, PR, and Her2 status and histological grade. Thus, Treg infiltration could help predict outcomes and guide clinical therapy.

Expression of Kif5b protein is significantly associated with the progression, recurrence and prognosis of oral squamous cell carcinoma

OBJECTIVE

Kinesin family member 5b (Kif5b), a conventional kinesin, mainly participates in lysosome and mitochondria transportation. Some studies have indicated that Kif5b may be associated with the development of a variety of tumors. However, the role Kif5b plays in oral squamous cell carcinoma (OSCC) has yet to be determined. Our study aimed at investigating the expression level of Kif5b in primary OSCC and discussing its clinical significance in patients' outcomes.

PATIENTS AND METHODS

We measured Kif5b expression in 82 OSCC tissue samples with immunohistochemistry. The associations between the expression level of Kif5b and clinicopathological characteristics as well as patients' survival were statistically assessed.

RESULTS

Kif5b level was significantly associated with tumor size (p=0.034), histological differentiation (p=0.028), disease recurrence (p=0.018), surrounding tissue invasion (p=0.045), recurrence time (p=0.036) and survival status (p=0.030). Kaplan-Meier cumulative survival analyses indicated that high expression of Kif5b was linked to worse overall survival (p=0.0112) and disease-free survival (p=0.0085). The univariate and multivariate Cox proportional hazard analysis further identified the expression status of Kif5b as an independent variable that correlated with patients' survival and recurrence. Furthermore, in 54 early-stage, clinically node negative OSCC patients, Kif5b expression were correlated with histological differentiation (p=0.034), disease recurrence (p=0.038) and surrounding tissue invasion (p=0.029). Univariate and multivariable logistic regression results showed that only Kif5b expression level could influence the probability of recurrence.

CONCLUSIONS

Our results reveal that Kif5b expression is associated with poor clinical outcome in OSCC and even in early-stage, clinically node negative OSCC and may be a potential target for OSCC treatment.