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1.
Preprint in English | bioRxiv | ID: ppbiorxiv-490381

ABSTRACT

While SARS-CoV-2 pathogenesis has been intensively investigated, the host mechanisms of viral clearance and inflammation resolution are still elusive because of the ethical limitation of human studies based on COVID-19 convalescents. Here we infected Syrian hamsters by authentic SARS-CoV-2 and built an ideal model to simulate the natural recovery process of SARS-CoV-2 infection from severe pneumonia1,2. We developed and applied a spatial transcriptomic sequencing technique with subcellular resolution and tissue-scale extensibility, i.e., Stereo-seq3, together with single-cell RNA sequencing (scRNA-seq), to the entire lung lobes of 45 hamsters and obtained an elaborate map of the pulmonary spatiotemporal changes from acute infection, severe pneumonia to the late viral clearance and inflammation resolution. While SARS-CoV-2 infection caused massive damages to the hamster lungs, including naive T cell infection and deaths related to lymphopenia, we identified a group of monocyte-derived proliferating Slamf9+Spp1+ macrophages, which were SARS-CoV-2 infection-inducible and cell death-resistant, recruiting neutrophils to clear viruses together. After viral clearance, the Slamf9+Spp1+ macrophages differentiated into Trem2+ and Fbp1+ macrophages, both responsible for inflammation resolution and replenishment of alveolar macrophages. The existence of this specific macrophage subpopulation and its descendants were validated by RNAscope in hamsters, immunofluorescence in hACE2 mice, and public human autopsy scRNA-seq data of COVID-19 patients. The spatiotemporal landscape of SARS-CoV-2 infection in hamster lungs and the identification of Slamf9+Spp1+ macrophages that is pivotal to viral clearance and inflammation resolution are important to better understand the critical molecular and cellular players of COVID-19 host defense and also develop potential interventions of COVID-19 immunopathology.

2.
Preprint in English | medRxiv | ID: ppmedrxiv-22273653

ABSTRACT

BackgroundSARS-CoV-2 Omicron variant BA.1 first emerged on the Chinese mainland in January 2022 in Tianjin and caused a large wave of infections. During mass PCR testing, a total of 430 cases infected with Omicron were recorded between January 8 and February 7, 2022, with no new infections detected for the following 16 days. Most patients had been vaccinated with SARS-CoV-2 inactivated vaccines. The disease profile associated with BA.1 infection, especially after vaccination with inactivated vaccines, is unclear. Whether BA.1 breakthrough infection after receiving inactivated vaccine could create a strong enough humoral immunity barrier against Omicron is not yet investigated. MethodsWe collected the clinical information and vaccination history of the 430 COVID-19 patients infected with Omicron BA.1. Re-positive cases and inflammation markers were monitored during the patients convalescence phase. Ordered multiclass logistic regression model was used to identify risk factors for COVID-19 disease severity. Authentic virus neutralization assays against SARS-CoV-2 wildtype, Beta and Omicron BA.1 were conducted to examine the plasma neutralizing titers induced after post-vaccination Omicron BA.1 infection, and were compared to a group of uninfected healthy individuals who were selected to have a matched vaccination profile. FindingsAmong the 430 patients, 316 (73.5%) were adults with a median age of 47 years, and 114 (26.5%) were under-age with a median age of 10 years. Female and male patients account for 55.6% and 44.4%, respectively. Most of the patients presented with mild (47.7%) to moderate diseases (50.2%), with only 2 severe cases (0.5%) and 7 (1.6%) asymptomatic infections. No death was recorded. 341 (79.3%) of the 430 patients received inactivated vaccines (54.3% BBIBP-CorV vs. 45.5% CoronaVac), 49 (11.4%) received adenovirus-vectored vaccines (Ad5-nCoV), 2 (0.5%) received recombinant protein subunit vaccines (ZF2001), and 38 (8.8%) received no vaccination. No vaccination is associated with a substantially higher ICU admission rate among Omicron BA.1 infected patients (2.0% for vaccinated patients vs. 23.7% for unvaccinated patients, P<0.001). Compared with adults, child patients presented with less severe illness (82.5% mild cases for children vs. 35.1% for adults, P<0.001), no ICU admission, fewer comorbidities (3.5% vs. 53.2%, P<0.001), and less chance of turning re-positive on nucleic acid tests (12.3% vs. 22.5%, P=0.019). For adult patients, compared with no prior vaccination, receiving 3 doses of inactivated vaccine was associated with significantly lower risk of severe disease (OR 0.227 [0.065-0.787], P=0.020), less ICU admission (OR 0.023 [0.002-0.214], P=0.001), lower re-positive rate on PCR (OR 0.240 [0.098-0.587], P=0.002), and shorter duration of hospitalization and recovery (OR 0.233 [0.091-0.596], P=0.002). At the beginning of the convalescence phase, patients who had received 3 doses of inactivated vaccine had substantially lower systemic immune-inflammation index (SII) and C-reactive protein than unvaccinated patients, while CD4+/CD8+ ratio, activated Treg cells and Th1/Th2 ratio were higher compared to their 2-dose counterparts, suggesting that receipt of 3 doses of inactivated vaccine could step up inflammation resolution after infection. Plasma neutralization titers against Omicron, Beta, and wildtype significantly increased after breakthrough infection with Omicron. Moderate symptoms were associated with higher plasma neutralization titers than mild symptoms. However, vaccination profiles prior to infection, whether 2 doses versus 3 doses or types of vaccines, had no significant effect on post-infection neutralization titer. Among recipients of 3 doses of CoronaVac, infection with Omicron BA.1 largely increased neutralization titers against Omicron BA.1 (8.7x), Beta (4.5x), and wildtype (2.2x), compared with uninfected healthy individuals who have a matched vaccination profile. InterpretationReceipt of 3-dose inactivated vaccines can substantially reduce the disease severity of Omicron BA.1 infection, with most vaccinated patients presenting with mild to moderate illness. Child patients present with less severe disease than adult patients after infection. Omicron BA.1 convalescents who had received inactivated vaccines showed significantly increased plasma neutralizing antibody titers against Omicron BA.1, Beta, and wildtype SARS-CoV-2 compared with vaccinated healthy individuals. FundingThis research is supported by Changping Laboratory (CPL-1233) and the Emergency Key Program of Guangzhou Laboratory (EKPG21-30-3), sponsored by the Ministry of Science and Technology of the Peoples Republic of China. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSPrevious studies (many of which have not been peer-reviewed) have reported inconsistent findings regarding the effect of inactivated vaccines against the Omicron variant. On Mar 6, 2022, we searched PubMed with the query "(SARS-CoV-2) AND ((Neutralisation) OR (Neutralisation)) AND ((Omicron) OR (BA.1)) AND (inactivated vaccine)", without date or language restrictions. This search identified 18 articles, of which 13 were directly relevant. Notably, the participants in many of these studies have received only one or two doses of inactivated vaccine with heterologous booster vaccination; other studies have a limited number of participants receiving inactivated vaccines. Added value of this studyTo date, this is the first study to report on the protective effect of inactivated vaccines against the severe disease caused by the Omicron variant. We examine and compare the disease profile of adults and children. Furthermore, we estimate the effect of post-vaccination omicron infection on plasma neutralization titers against Omicron and other SARS-COV-2 variants. Specifically, the disease profile of Omicron convalescents who had received two-dose primary series of inactivated vaccines with or without a booster dose prior to infection is compared with unvaccinated patients. We also analyzed the effect of infection on neutralizing activity by comparing vaccinated convalescents with vaccinated healthy individuals with matched vaccination profiles. Implications of all the available evidenceCompared with adults, child patients infected with Omicron tend to present with less severe disease and are less likely to turn re-positive on nucleic acid tests. Receipt of two-dose primary series or three doses of inactivated vaccine is a protective factor against severe disease, ICU admission, re-positive PCR and longer hospitalization. The protection afforded by a booster dose is stronger than two-dose primary series alone. Besides vaccination, infection with Omicron is also a key factor for elevated neutralizing antibody titers, enabling cross-neutralization against Omicron, wildtype (WT) and the Beta variant.

3.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-604418

ABSTRACT

Objective To analyze non -small cell lung cancer patients with platinum -based chemotherapy excision repair cross -complementing 1 (ERCC1)and breast cancer susceptibility gene 1 (BRCA1 )gene polymor-phism,to examine the correlation of ERCC1 and BRCA1 gene polymorphism and non -small cell lung cancer platinum chemotherapy drugs sensitivity and chemotherapy prognosis.Methods 140 cases of non -small cell lung cancer were selected as subjects of this study.All patients were given platnum -based chemotherapy,peripheral blood ERCC1 and BRCA1 genes polymorphism were determined.The distribution of ERCC1 Asn118Asn genotype and BRCA1 Ser1613Gly genotype was observed.The relationship between different genotypes and the effect of chemotherapy and survival time after chemotherapy was compared.Results The proportions of ERCC1 Asn118Asn TT genotype,CT genotype and CC genotype were 5.7%,30.7% and 63.6%.The proportions of BRCA1 Ser1613Gly GG genotype,AG genotype and AA genotype were 8.6%,52.9% and 38.6%.In 140 patients,completely cured,partial response,stable disease and progressive disease patients were 0 case,33 cases,61 cases and 46 cases,the proportions were 0.0%, 23.6%,43.6% and 32.9%,the chemotherapy effective rate was 33.8%.ERCC1 Asn118Asn genotype was signifi-cantly correlated with the effect of non -small cell lung cancer chemotherapy (χ2 =4.416,P <0.05 ).BRCA1 Ser1613Gly genotype was significantly correlated with the effect of non -small cell lung cancer chemotherapy (χ2 =13.256,P <0.05).By Cox regression analysis and Log -rank test analysis,the average survival time of BRCA1 Ser1613Gly gene CC genotype non -small cell lung cancer after chemotherapy was longer than the CT +TT genotype (OR =2.946,χ2 =5.136,P <0.05).The average survival time of BRCA1 Ser1613Gly gene AA genotype non -small cell lung cancer after chemotherapy was shorter than the AG +GG genotype (OR =3.124,χ2 =5.136,P <0.05).Conclusion ERCC1 Asn118Asn genotype and BRCA1 Ser1613Gly genotype was significantly correlated with non -small cell lung cancer platinum -based chemosensitivity and chemotherapy prognosis.

4.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-556861

ABSTRACT

Objective To study the effect of Vincristine-loaded intact human erythrocytes on tumor cell in vitro. Methods VCR was loaded in intact human erythrocytes using a modified hypotonic preswelling technique. The proliferation of K562 cells after incubation with VCR-loaded erythrocytes was detected by MTT. Cellular cycle and apoptosis of K562 cells were analyzed through FACS staining with PI/Rhodamin123, and morphology of apoptotic K562 cells and their nucleus were observed through staining with Hoechest33258. Results VCR-loaded erythrocytes could efficiently inhibit the proliferation of co-cultured K562 cells and induce the cells′ apoptosis in a dosage-dependent manner. Cellular cycle analysis demonstrated that proportion of K562 cells in G 0/G 1 decreased whereas in S+G 2/M increased after incubation with VCR-loaded erythrocytes. Such effects could also be displayed from alone VCR group, and significant change was observed in K562 cells co-cultured with unloaded erythrocytes (P

5.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-518975

ABSTRACT

Objective To investigate the expression of IL-8 and CXCR2 on keratinocytes from psoriatic lesions and their roles on clinical and pathologic manifestations. Methods The chemotaxis of psoriatic lesional keratinocytes was detected by micropore loculus test. The concentration of IL-8 was determined in the cultured supernatants of psoriatic keratinocytes by ELISA. The expression of CXCR2 on keratinocytes from affected skin was tested by flow cytometry. Results The chemotaxis for neutrophils by the cultured supernatants of psoriatic lesional keratinocytes was significantly stronger than that by controls. The concentration of IL-8 in the cultured supernatants of psoriatic lesional keratinocytes was also increased. The expression of CXCR2 on psoriatic keratinocytes was significantly increased. Conclusions The psoriatic epidermal hyperproliferation may be correlated with up regulation of IL-8 production and CXCR2 expression on psoriatic keratinocytes. At the same time, the psoriatic inflammation may be partly related to the increase of secretion of IL-8, which has chemotactic capacity, by keratinocytes. IL-8 and CXCR2 may be involved in the pathogenesis of psoriasis.

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