Construction of recombinant SAG22 Bacillus subtilis and its effect on immune protection of coccidia.

Avian coccidiosis causes huge economic losses to the global poultry industry. Vaccine is an important means to prevent and control coccidiosis. In this study, Bacillus subtilis was selected as the expression host strain to express anti Eimeria tenella surface protein SAG22. The synthesized surface protein SAG22 gene fragment of E. tenella was ligated with Escherichia coli-bacillus shuttle vector GJ148 to construct the recombinant vector SAG22-GJ148. And then the recombinant Bacillus strain SAG22-DH61 was obtained by electrotransfer. The results of SDS-PAGE and Western Blot showed that the recombinant protein SAG22 was successfully expressed intracellularly. The immunoprotective effect of recombinant Bacillus strain SAG22-DH61 on broiler chickens was evaluated in 3 identically designed animal experiments. The birds were infected with E. tenella on d 14, 21, and 28, respectively. Each batch of experiments was divided into 4 groups: blank control group (NC), blank control group + infected E. tenella (CON), addition of recombinant SAG22-DH61 strain + infected with E. tenella (SAG22-DH61), addition of recombinant empty vector GJ148-DH61 strain + infected with E. tenella (GJ148-DH61). The animal experiments results showed that the average weight gain of the SAG22-DH61 group was higher than that of the infected control group, and the difference was significant in the d 14 and 28 attack tests (P < 0.05); the oocyst reduction rate of the SAG22-DH61 group was much higher than that of the GJ148-DH61 group (P < 0.05); the intestinal lesion count score of the SAG22-DH61 group was much lower than that of the GJ148-DH61 group (P < 0.05). In addition, the SAG22-DH61 group achieved highly effective coccidia resistance in the d 14 attack test and moderately effective coccidia resistance in both the d 21 and 28 attack tests. In summary, recombinant SAG22 B. subtilis has the potential to become one of the technological reserves in the prevention and control of coccidiosis in chickens in production.

Three-dose vaccination-induced immune responses protect against SARS-CoV-2 Omicron-BA.2

BackgroundThe ongoing outbreak of SARS-CoV-2 Omicron BA.2 infections in Hong Kong, the model city of universal masking of the world, has resulted in a major public health crisis. Although the third vaccination resulted in strong boosting of neutralization antibody, vaccine efficacy and corelates of immune protection against the major circulating Omicron BA.2 remains to be investigated. MethodsWe investigated the vaccine efficacy against the Omicron BA.2 breakthrough infection among 470 public servants who had received different SARS-CoV-2 vaccine regimens including two-dose BNT162b2 (2xBNT, n=169), three-dose BNT162b2 (3xBNT, n=170), two-dose CoronaVac (2xCorV, n=34), three-dose CoronaVac (3xCorV, n=67) and third-dose BNT162b2 following 2xCorV (2xCorV+1BNT, n=32). Humoral and cellular immune responses after three-dose vaccination were further characterized and correlated with clinical characteristics of BA.2 infection. FindingsDuring the BA.2 outbreak, 27.7% vaccinees were infected. The timely third-dose vaccination provided significant protection with lower incidence rates of breakthrough infections (2xBNT 49.2% vs 3xBNT 13.1%, p <0.0001; 2xCorV 44.1% vs 3xCoV 19.4%, p=0.003). Investigation of immune response on blood samples derived from 92 subjects in three-dose vaccination cohorts collected before the BA.2 outbreak revealed that the third-dose vaccination activated spike (S)-specific memory B cells and Omicron cross-reactive T cell responses, which correlated with reduced frequencies of breakthrough infections and disease severity rather than with types of vaccines. Moreover, the frequency of S-specific activated memory B cells was significantly lower in infected vaccinees than uninfected vaccinees before vaccine-breakthrough infection whereas IFN-{gamma}+ CD4 T cells were negatively associated with age and viral clearance time. Critically, BA.2 breakthrough infection boosted cross-reactive memory B cells with enhanced cross-neutralizing antibodies to Omicron sublineages, including BA.2.12.1 and BA.4/5, in all vaccinees tested. InterpretationOur results imply that the timely third vaccination and immune responses are likely required for vaccine-mediated protection against Omicron BA.2 pandemic. Although BA.2 conferred the highest neutralization resistance compared with variants of concern tested before the emergence of BA.2.12.1 and BA.4/5, the third dose vaccination-activated S-specific memory B cells and Omicron cross-reactive T cell responses contributed to reduced frequencies of breakthrough infection and disease severity. Neutralizing antibody potency enhanced by BA. 2 breakthrough infection with previous 3 doses of vaccines (CoronaVac or BNT162b2) may reduce the risk for infection of ongoing BA.2.12.1 and BA.4/5. FundingHong Kong Research Grants Council Collaborative Research Fund, Health and Medical Research Fund, Wellcome Trust, Shenzhen Science and Technology Program, the Health@InnoHK, Innovation and Technology Commission of Hong Kong, China, National Program on Key Research Project, Emergency Key Program of Guangzhou Laboratory, donations from the Friends of Hope Education Fund and the Hong Kong Theme-Based Research Scheme.

An elite broadly neutralizing antibody protects SARS-CoV-2 Omicron variant challenge

The strikingly high transmissibility and antibody evasion of SARS-CoV-2 Omicron variant have posted great challenges on the efficacy of current vaccines and antibody immunotherapy.Here, we screened 34 BNT162b2-vaccinees and cloned a public broadly neutralizing antibody (bNAb) ZCB11 from an elite vaccinee. ZCB11 neutralized all authentic SARS-CoV-2 variants of concern (VOCs), including Omicron and OmicronR346K with potent IC50 concentrations of 36.8 and 11.7 ng/mL, respectively. Functional analysis demonstrated that ZCB11 targeted viral receptor-binding domain (RBD) and competed strongly with ZB8, a known RBD-specific class II NAb. Pseudovirus-based mapping of 57 naturally occurred single mutations or deletions revealed that only S371L resulted in 11-fold neutralization resistance, but this phenotype was not observed in the Omicron variant. Furthermore,prophylactic ZCB11 administration protected lung infection against both the circulating pandemic Delta and Omicron variants in golden Syrian hamsters. These results demonstrated that vaccine-induced ZCB11 is a promising bNAb for immunotherapy against pandemic SARS-CoV-2 VOCs.

Vaccine-breakthrough infection by the SARS-CoV-2 Omicron variant elicits broadly cross-reactive immune responses

Highly transmissible SARS-CoV-2 Omicron variant has posted a new crisis for COVID-19 pandemic control. Within a month, Omicron is dominating over Delta variant in several countries probably due to immune evasion. It remains unclear whether vaccine-induced memory responses can be recalled by Omicron infection. Here, we investigated host immune responses in the first vaccine-breakthrough case of Omicron infection in Hong Kong. We found that the breakthrough infection rapidly recruited potent cross-reactive broad neutralizing antibodies (bNAbs) against current VOCs, including Alpha, Beta, Gamma, Delta and Omicron, from unmeasurable IC50 values to mean 1:2929 at around 9-12 days, which were higher than the mean peak IC50 values of BioNTech-vaccinees. Cross-reactive spike- and nucleocapsid-specific CD4 and CD8 T cell responses were detected. Similar results were also obtained in the second vaccine-breakthrough case of Omicron infection. Our preliminary findings may have timely implications to booster vaccine optimization and preventive strategies of pandemic control.

Waning immune responses against SARS-CoV-2 among vaccinees in Hong Kong

BackgroundNearly 4 billion doses of the BioNTech-mRNA and Sinovac-inactivated vaccines have been administrated globally, yet different vaccine-induced immunity against SARS-CoV-2 variants of concern (VOCs) remain incompletely investigated. MethodsWe compare the immunogenicity and durability of these two vaccines among fully vaccinated Hong Kong people. FindingsStandard BioNTech and Sinovac vaccinations were tolerated and induced neutralizing antibody (NAb) (100% and 85.7%) and spike-specific CD4 T cell responses (96.7% and 82.1%), respectively. The geometric mean NAb IC50 and median frequencies of reactive CD4 subsets were consistently lower among Sinovac-vaccinees than BioNTech-vaccinees. Against VOCs, NAb response rate and geometric mean IC50 against B1.351 and B.1.617.2 were significantly lower for Sinovac (14.3%, 15 and 50%, 23.2) than BioNTech (79.4%, 107 and 94.1%, 131). Three months after vaccinations, NAbs to VOCs dropped near to detection limit, along with waning memory T cell responses, mainly among Sinovac-vaccinees. InterpretationOur results indicate that Sinovac-vaccinees may face higher risk to pandemic VOCs breakthrough infection. FundingThis study was supported by the Hong Kong Research Grants Council Collaborative Research Fund (C7156-20GF to Z.C and C1134-20GF); the National Program on Key Research Project of China (Grant 2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); Shenzhen Science and Technology Program (JSGG20200225151410198 and JCYJ20210324131610027); HKU Development Fund and LKS Faculty of Medicine Matching Fund to AIDS Institute; Hong Kong Innovation and Technology Fund, Innovation and Technology Commission and generous donation from the Friends of Hope Education Fund. Z.C.s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).

Nasal prevention of SARS-CoV-2 infection by intranasal influenza-based boost vaccination

BackgroundVaccines in emergency use are efficacious against COVID-19, yet vaccine-induced prevention against nasal SARS-CoV-2 infection remains suboptimal. MethodsSince mucosal immunity is critical for nasal prevention, we investigated an intramuscular PD1-based receptor-binding domain (RBD) DNA vaccine (PD1-RBD-DNA) and intranasal live attenuated influenza-based vaccines (LAIV-CA4-RBD and LAIV-HK68-RBD) against SARS-CoV-2. FindingsSubstantially higher systemic and mucosal immune responses, including bronchoalveolar lavage IgA/IgG and lung polyfunctional memory CD8 T cells, were induced by the heterologous PD1-RBD-DNA/LAIV-HK68-RBD as compared with other regimens. When vaccinated animals were challenged at the memory phase, prevention of robust SARS-CoV-2 infection in nasal turbinate was achieved primarily by the heterologous regimen besides consistent protection in lungs. The regimen-induced antibodies cross-neutralized variants of concerns. Furthermore, LAIV-CA4-RBD could boost the BioNTech vaccine for improved mucosal immunity. InterpretationOur results demonstrated that intranasal influenza-based boost vaccination is required for inducing mucosal and systemic immunity for effective SARS-CoV-2 prevention in both upper and lower respiratory systems. FundingThis study was supported by the Research Grants Council Collaborative Research Fund (C7156-20G, C1134-20G and C5110-20G), General Research Fund (17107019) and Health and Medical Research Fund (19181052 and 19181012) in Hong Kong; Outbreak Response to Novel Coronavirus (COVID-19) by the Coalition for Epidemic Preparedness Innovations; Shenzhen Science and Technology Program (JSGG20200225151410198); the Health@InnoHK, Innovation and Technology Commission of Hong Kong; and National Program on Key Research Project of China (2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); and donations from the Friends of Hope Education Fund. Z.C.s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).

Progression in photoacoustic imaging for cancer diagnosis and therapy / 中华核医学与分子影像杂志

Photoacoustic imaging (PAI) is an emerging new biomedical imaging technique integrated with the high spatial resolution of ultrasonic imaging and high contrast of optical imaging for real-time molecular imaging.PAI is well-suited for in vivo cellular/molecular signatures imaging in cancer diagnosis, therapy management and treatment response, with a promising potential in clinical and translational medicine.This review summarizes the current state of PAI application research on cancer theranostics, and gives insights on future translational medicine research.

Investigation on AIDS cognition and sexual behavior among patients with HIV/AIDS in shenzhen in 2016 / 中华实验和临床病毒学杂志

Objective@#To investigate the situations of AIDS related knowledge, sexual behavior with various partners among HIV positive patients in Shenzhen before highly active anti-retroviral therapy, and to provide evidences for health education intervention.@*Methods@#Questionnaire survey and information collection were carried out among HIV positive patients, under the informed consent, during the first physical examination before highly active anti-retroviral therapy.@*Results@#The overall awareness rate of AIDS knowledge was 91%, 94.46% and 80.95% respectively for homosexual and heterosexual populations, with significant difference between the two groups (χ2=21.254, P<0.001). In addition, there were significant differences in the factors related to education, income, route of infection, marital status, residence and other related factors (P<0.05). In HIV positive MSM, primary sexual behavior occurred mainly at the age of less than 30 (96.8%) and in university or earlier stage (58.3%), college students as the first sexual partner accounted for 44.9%, and once used Rush accounted for 42.7%. There were significant differences in the number of temporary sexual partners and condom use frequency between homosexual and heterosexual subjects (P<0.05).@*Conclusions@#Individuals infected with HIV via different routes are variant on AIDS cognition. Health education on AIDS related knowledge and sexual security before and after antiviral treatment can not only improve the awareness rate of HIV/AIDS infection, but also can reduce the risk of the spread of HIV/AIDS.

Comparison of an in-house tuberculosis-specific IFN-γ release assays with T-SPOT TB in latent tuberculosis infection diagnosis among HIV-infected individuals / 中华检验医学杂志

Objective To evaluate the diagnostic value of two tuberculosis-specific IFN-γ release assays in latent tuberculosis infection among HIV-infected individuals. Methods The levels of tuberculosis antigen-specific IFN-γin 102 HIV patients from AIDS Outpatient Clinic of Shenzhen Third People's Hospital were detected by in-house tuberculosis-specific IFN-γ ELISpot assay and commercial T-SPOT TB kit, and tuberculin skin test (TST) were done at the same time. There were 66 males and 36 females,and the average age was 35. Results Seventeen HIV infected patients were positive in both IFN-γ ELISpot and T-SPOT TB methods, the sensitivity, specificity positive predictive value(PPV), negative predictive value(NPV) and compliance rates of ELISpot were 94. 4% ,94. 0% ,77. 3% ,98. 8% and 94. 1% ,respectively. Three patients were positive in both IFN-γELISpot and T-SPOT TB methods, the sensitivity, specificity, PPV, NPV and compliance rates of TST were 16. 7%, 98. 8%, 75.0%, 84. 7% and 84. 3%, respectively. The average number of spots using three kinds of antigen ESAT-6, Pool A,Pool B obtained were 26. 89 ±5. 77,18. 96 ±4. 75 and 14. 51 ± 3.77, respectively. Only ESAT-6 and Pool B have a statistically significant difference (H=7.557,P = 0.022 9), no significant difference was shown between other groups. There was no significant difference between the positive rate and the CD4+ T cellls number(x2 =0. 860 8 ,P =0. 650 2) ,as the same as the T-SPOT TB (x2 = 1. 396 4, P = 0. 497 5 ). Conclusions The performance of this in-house tuberculosis-specific IFN-γ ELISPot assay was comparable to T-SPOT assay in diagnosis of latent tuberculosis infection, and the sensitivity and specificity of both these two assays were all much higher than TST. They canbe recommended in diagnosing latent tuberculosis infection in HIV infected patients.

The role of T helper type 17 cells in the pathogenesis of HIV/tuberculosis-coinfected patients / 中华传染病杂志

ObjectiveTo evaluate the IL-17 expression in HIV/tuberculosis-coinfected patients and its role in the pathogenesis of this coinfection.MethodsFifty-four HIV infected patients were divided into three groups:simple HIV infected group,HIV with latent tuberculosis infection (HIV+ LTBI) group and HIV coinfected with active tuberculosis (HIV+ ATB) group.The whole blood intracellular cytokine staining was performed and samples were then detected by BD FACSCanto.The expressions of CD4+ IL-17+ T cells and CD4+ IFNγ+ T cells were analyzed using FACSDiva software.Comparison between groups was done by independent sample t test.ResultsThe CD4+ T cell count and viral load among these three groups were comparable.There were no significant difference of the expression of CD4+ IL-17+ T cells between simple HIV infected group and HIV+ LTBI group (1.40 ± 1.01) ％ vs (1.29±0.86) ％,(t=0.336,P＞0.05),but both of these two groups were much higher than HIV+ATB group (t=3.680,t=2.516,P＜0.05).There were no significant differences of the expression of CD4+ IFNγ+ T cells among these three groups [(32.8±24.0)％ vs (40.3±1 21.9) ％ vs (46.1±31.2)％,(t=-0.939,t=-1.602,t=-0.646,P＞0.05)].ConclusionThe Th17 response is down-regulated in HIV/tuberculosis-coinfected patients,which may play an important antitubercular role in the pathogenesis of coinfection.

Study of the expression of complement regulatory protein CD59 on CD4+ T cells and its relationship with apoptosis in HIV infected patients / 中国基层医药

Objective To explore CD59 expression on CD4+T cells in HIV infected patients and its relationship with apoptosis.Methods 12 HIV infected patients and 10 healthy donors were performed in this study.The PBMC(peripheral blood monocyte)were collected and cell surface cytokine were stained,and then were evaluated with the BD FACSCanto flow cytometry.The expression of CD59 on T lymphocyte subsets were analyzed by FACSDiva software,and the apoptosis rate of CD59+CD4+T cells and CD59-CD4+T cells in every group was analyzed respectively,then the results were compared between groups.Results Compared with healthy donor,the expression of CD59 on T cells in HIV infected patients was significantly hisher(t=5.198,P＜0.01),and the apoptosis rate of CD59+CD4+T cells had significantly higher(t=5.968,P＜0.01).The apoptosis rate of CD59-CD4+T cells was no difference between two groups (t=0.1353,P=0.8577).Condnsion HIV infection increase CD59 expression on CD4+T cells,and CD59+CD4+T cells were prone to apoptosis.

A study on T lymphocyte apoptosis and disease progression in chronic HIV/AIDS patients / 中华微生物学和免疫学杂志

Objective To discuss the relationship between various T lymphocyte subsets apoptosis and disease progression in chronic antiretroviral-naive HIV/AIDS patients. Methods Thirty-six chronic antiretrovi-ral-naive HIV-infected individuals as well as 16 healthy HIV-negative controls were performed in this study. Ac-cording to the CD4~+ T cell counts, all the patients were divided three groups: < 200/μl, 200-350/μl and > 350/μl. After the peripheral blood mononuclear cells(PBMC) were isolated, T lymphocyte subpopulations were determined by the expression of CD45RO and CD27, and the apoptosis of different T cell subsets were measured by Annexin V staining, then analyzed by flow cytometry. To investigate whether the apoptosis of T cells varied with the culture time in vitro, 4 healthy controls and 4 patients were chosen as subjects, and the lev-els of cell apoptosis were analyzed at the culture time points of 0, 3, 6, 12, 24 h. Results (1)The percenta-ges of the AnnexinV expression on CD4~+ and CD8~+ T cells and all the subsets in HIV/AIDS patients were sig-nificantly higher than that in the healthy controls (P<0.05), but there were no significant differences among the three HIV-infected patient groups(P>0.05). (2) No significant correlations were observed between the levels of apoptosis of all the T cells and subsets and total CD4~+ T cell counts(P>0.05) ,nor with the HIV viral load (P>0.05). (3)As the culture time prolonged in vitro, the levels of apoptosis and necrosis of CD4~6 T cells in HIV/AIDS patients were significantly higher than those in the healthy conlrols, and the CD4~+ T cells were more susceptible to apoptosis and necrosis compared with CD8~+ T cells. Conclusion The levels of T cell apoptosis in HIV/AIDS patients was significantly higher than those in the healthy controls, at the same time, CD4~+ T cells were more susceptible to apoptosis and necrosis compared with CD8~+ T cells, but no correlation was found between the T cell apoptsis and disease progression.

Relationship of proliferation and activation of T lymphocyte subsets and disease progression in human immunodeficiency virus-I-infected individuals / 中华传染病杂志

Objective To study the relationship of proliferation and activation of T lymphocyte subsets and disease progression in antiretroviral-naive human immunodeficiency virus(HIV)-1-infected individuals.Methods Forty-nine antiretroviral-naive,chronically HIV-1 infected patients and 16 healthy,HIV-1 negative controls were enrolled in this study.The patients were divided into 3 groups according to their CD4+T cell counts:<200×106/L,(200-350)×106/L and>350×106/L.Peripheral blood mononuclear cells(PBMC)were isolated.T cell proliferation index was measured by Ki-67 staining.T cell activation was detected by CD38 staining.The samples were analyzed by flow cytometry.The data were compared by one-way ANOVA.Results The percentage of Ki-67+cells in CIM+T ceils was 7.92%±4.37%in CD4+T cell<200×106/L group,which was significantly higher than those 0.39%d:0.24%in control group,2.61%±2.12%in(200-350)×106/k group and 2.65%±2.13%in>350 X106/L group(F=21.961,P<0.01).The percentage of Ki-67+cells in CD8+T ceils in CD4+T cells<200×106/L group was 2.87%±1.13%,which was also much higher than those in other 3 groups(0.15%±0.90%,1.40%±1.17%,1.22%±0.80%,respectively F=19.203,P<0.01).The Ki-67'CD4'T cells and Ki-67+CD8+T cells were inversely correlated with CD4+T cell counts(r=-0.654,r=-0.539,respectively;P<O.01),while were not correlated with viral load.The percentages of CD38+CD4+in CD4+T cells and CD38+CD8+in CD8+T cells were 44.14%±20.65%,50.64%±21.08%,respectively in CD4+T cells<200X 106/L group,and those were 10.22%±3.98%,6.46%±3.99%,respectively in control group,16.03%±10.20%,19.33%±13.43%,respectively in CD4+T cells(200-350)×106/Lgroup,13.69%±10.70%,16.98%±15.75%,respectively in CIM'T cells>350×106/L group(F=14.333,F=15.412,respectively;P<0.01).The expressions of Ki-67+ on CD4+ and CD8+T cells were positively correlated with CD38 expression(r=0.527,r=0.391,respectively;P=0.002).Conclusions The proliferation and activation of T lymphoeytes are enhanced during HIV/AIDS disease progression.And T eell activation may be the result of persistent immune activation.