Cross-protective characteristics of specific immune response induced by HSV-1 attenuated strain M3 against HSV-2 infection / 中华微生物学和免疫学杂志

Objective:To analyze the characteristics of immune cross-reaction between herpes simplex virus type 1 (HSV-1) and HSV-2 in terms of serology and clinical protection aiming to provide data for the control and prevention of diseases caused by the two viruses.Methods:An attenuated HSV-1 strain M3 was used to immunize BALB/c mice. Specific immune responses indicated by the production of neutralizing antibodies were detected. Wild-type HSV-1 and HSV-2 strains were respectively used to infect the mice through different ways 28 d after the immunization to observe the protective immunity in the M3-immunized mice against HSV-1/2 infection.Results:M3 strain could not induce specific neutralizing antibodies against HSV-2. Therefore, viral loads in tissues of the immunized mice increased significantly following different modes of HSV-2 exposure. However, no obvious abnormal clinical manifestations were found and the histopathological damage was only slight inflammatory reaction. In contrast, HSV-1-specific neutralizing antibodies were elicited in the M3-immunizaed mice with significant protective effects against HSV-1 infection.Conclusions:The immune response induced by attenuated HSV-1 strain M3 in mice exhibited immune-protective effects characterized by production of neutralizing antibodies and inhibition of virus proliferation in vivo against wild-type HSV-1 infection. For HSV-2, instead of neutralizing virus in form of antibodies, it featured by more of clinical cross-immunoprotective abilities to control virus growth.

An in-depth investigation of the safety and immunogenicity of an inactivated SARS-CoV-2 vaccine

BACKGROUNDIn-depth investigations of the safety and immunogenicity of inactivated SARS-CoV-2 vaccines are needed. METHODIn a phase I randomized, double-blinded, and placebo-controlled trial involving 192 healthy adults 18-59 years of age, two injections of three different doses (50 EU, 100 EU and 150 EU) of an inactivated SARS-CoV-2 vaccine or the placebo were administered intramuscularly with a 2- or 4-week interval between the injections. The safety and immunogenicity of the vaccine were evaluated within 28 days. FINDINGIn this study, 191 subjects assigned to three doses groups or the placebo group completed the 28-day trial. There were 44 adverse reactions within the 28 days, most commonly mild pain and redness at the injection site or slight fatigue, and no abnormal variations were observed in 48 cytokines in the serum samples of immunized subjects. The serum samples diluted from 1:32 to 1:4096 and incubated with the virus did not show antibody-dependent enhancement effects (ADEs) with regard to human natural killer cells, macrophages or dendritic cells. At day 14, the seroconversion rates had reached 92%, 100% and 96% with geometric mean titers (GMTs) of 18.0, 54.5 and 37.1, and at day 28, the seroconversion rates had reached 80%, 96% and 92% with GMTs of 10.6, 15.4 and 19.6in 0, 14 and 0, 28 procedures, respectively. Seroconversion was associated with the synchronous upregulation of ELISA antibodies against the S protein, N protein and virion and a cytotoxic T lymphocyte (CTL) response. Transcriptome analysis shaped the genetic diversity of immune response induced by the vaccine. INTERPRETATIONIn a population aged 18-59 years, this inactivated SARS-CoV-2 vaccine was safe and immunogenic. Trial registrationNCT04412538 FUNDINGThe National Key R&D Program of China (2020YFC0849700), the Program of Chinese Academy of Medicine Science and the Major Science and Technology Special Projects of Yunnan Province.

A valid protective immune response elicited in rhesus macaques by an inactivated vaccine is capable of defending against SARS-CoV-2 infection

With the relatively serious global epidemic outbreak of SARS-CoV-2 infection, public concerns focus on not only clinical therapeutic measures and public quarantine for this disease but also the development of vaccines. The technical design of our SARS-CoV-2 inactivated vaccine provides a viral antigen that enables the exposure of more than one structural protein based upon the antibody composition of COVID-19 patients convalescent serum. This design led to valid immunity with increasing neutralizing antibody titers and a CTL response detected post-immunization of this vaccine by two injections in rhesus macaques. Further, this elicited immunoprotection in macaques enables not only to restrain completely viral replication in tissues of immunized animals, compared to the adjuvant control and those immunized by an RBD peptide vaccine, but also to significantly alleviate inflammatory lesion in lung tissues in histo-pathologic detection, compared to the adjuvant control with developed interstitial pneumonia. The data obtained from these macaques immunized with the inactivated vaccine or RBD peptide vaccine suggest that immunity with a clinically protective effect against SARS-CoV-2 infection should include not only specific neutralizing antibodies but also specific CTL responses against at least the S and N antigens.

Pathogenesis of nasal and genital infection with herpes simplex virus type Ⅱ in BALB/c mice / 中华微生物学和免疫学杂志

Objective To observe and analyze the pathological changes in BALB/c mice infected with herpes simplex virus typeⅡ (HSV-2) through nasal and genital inoculation. Methods Six-week old female BALB/c mice were divided into two groups, experimental and control groups. In the experimental group, the mice were infected with HSV-2 (104 CCID50/20μl per mouse) through nasal and genital tract in-oculation. Accordingly, the mice in the control group were injected with equal volume of PBS. Tissue speci-mens were collected from lung, nervous system and reproductive system for pathological analysis and viral load detection at different time points after infection. Lat gene expression in mouse trigeminal and sacral gan-glia was detected through in situ hybridization. In addition, the proliferation of viruses isolated form trigemi-nal and sacral ganglia of the infected mice was observed in vitro. Results Weight loss and histopathological lesions were observed in the mice of the experimental group 6 d after infection. Major pathological changes in the HSV-2-infected mice through nasal tract inoculation involved the lung and central nervous system( CNS) , including alveolar wall congestion, cerebrovascular cuff response and lymphocyte infiltration. How-ever, the major lesions in the infected mice through genital tract inoculation were found in the reproductive ducts, such as sacral ganglion necrosis, eosinophilia in the vagina and uterus, and ovarian congestion. Re-sults of the viral load detection in tissues and organs of the infected mice were consistent with the pathological changes. The mice infected through nasal tract inoculation had significantly higher viral loads in the nerves and lungs than those by genital tract inoculation, but lower viral loads in the genital tracts and sacral ganglia. Positive expression of lat gene at mRNA level was detected in the trigeminal and sacral ganglia of mice with HSV-2 latency 28 d after infection. In addition, both of the tissue fragments from trigeminal and sacral ganglia had cytopathic effects ( CPEs) on Vero cells. Enhanced expression of lat gene at mRNA level and much severer CPEs were induced by genital tract inoculation than by nasal tract inoculation. Conclu-sions HSV-2 could infect and cause histopathological damages in BALB/c mice through both nasal and genital tracts. In addition, the locations of the pathological lesions were closely related to the mode of infection.

Differences in clinical, pathological and etiological features of herpes simplex virus 1 infection in different BALB/c mouse models / 中华微生物学和免疫学杂志

Objective To provide a comprehensive reference index for different mouse models of herpes simplex virus 1 (HSV-1) infection by investigating the related clinical manifestations, pathological features and characteristics of viral distribution in tissues and organs of BALB/c mice infected with different HSV-1 strains by using different strategies.Methods Acute infection models were established by challenging BALB/c mice at age three or six weeks with HSV-1 17+ and McKrae strains via intranasal and corneal administrations.Correspondingly, chronic infection models were established with BALB/c mice through subcutaneous and foot pad injections.Results Although all experimental mice showed trichiasis and roachback, there were differences in weight and fatality rate among different groups.Results of the quantitative PCR detection indicated that the proliferation of HSV-1 in the nervous tissues (brain, spinal cord, trigeminal ganglion) varied among different groups.The pathological examination indicated that in the acute infection groups, significant pathological changes only occurred in the brain tissues, while in the chronic infection groups, pathological injuries only occurred in the trigeminal ganglia.Although a key index latency-associated transcript (LAT) was not detected in the trigeminal nerve tissues of mice in the chronic infection groups, co-culturing the tissues with Vero cells resulted in infectious lesions in the cells.Conclusion This study indicates that there are significant differences in weight and fatality rate among different BALB/c mouse models of HSV-1 infection.Varied replication dynamics of HSV-1 were observed in different tissues or organs of the BALB/c mice in different groups.Therefore, different indexes should be adopted to evaluate different HSV-1 infection models.

Application of genome editing technologies in researches on herpes simplex virus 1 / 中华微生物学和免疫学杂志

The viral genome editing technologies have been shown to largely contribute to the stud-ies of viral gene functions and to the treatment of infectious diseases. With the development of genetic engi-neering technologies, a variety of viral genome mutation technologies have been established. The homologous recombination is traditionally used to edit the viral genome, but the low frequency of homologous recombina-tion limits its application. Large genome DNA viruses including herpes simplex virus 1 can be edited by bac-terial artificial chromosome system. However, the cloning of viral genome to bacterial artificial chromosome plasmid is both laborious and time-consuming, and parts of the plasmid genes or drug selection markers may remain in the genome of virus and then affect the function of virus. Fortunately, the CRISPR-cas9 system which was discovered in 2013 can be used to edit the viral genome efficiently and accurately. Furthermore, the experiment is simple and will not leave any trail of the viral genome when the genetic mutation is per-formed. Here, we briefly review the application of homologous recombination, bacterial artificial chromosome system and CRISPR-cas9 system in researches on herpes simplex virus 1.

Cloning of UL7 protein of HSV-1 and analysis of the expression of UL7 protein during the prolifera-tion of HSV-1 / 中华微生物学和免疫学杂志

Objective To express and purify the recombinant UL7 protein of herpes simplex virus 1 (HSV-1), to prepare the corresponding UL7-specific polyclonal antibody and to preliminarily analyze the expression of UL7 protein during the proliferation of HSV-1. Methods The UL7 gene was amplified by PCR and then cloned into the pGEX-5X-1 vector for expression of UL7 protein in the prokaryotic expression system. The constructed expression plasmid, pGEX-5X-1-UL7, was transformed into E. coli BL21 (DE3) to induce the expression of UL7 protein by IPTG. The purified GST-UL7 fusion protein was used as antigen to inject the ICR mouse for the preparation of polyclonal antibody specific for UL7 protein. The titer and speci-ficity of the polyclonal antibody were analyzed by using indirect ELISA and Western blot assay, respectively. The UL7 protein-specific polyclonal antibody was used to detect the expression of UL7 protein at different time points after infecting Vero cells with HSV-1. Results The GST-UL7 fusion protein was efficiently ex-pressed in E. coli BL21 (DE3). The UL7 protein-specific polyclonal antibody was prepared with high titer (1 ∶ 105) and high specificity as indicated by the indirect ELISA and Western blot assay. The expression of UL7 protein was detected at different time points after infecting Vero cells with HSV-1. Conclusion The GST-UL7 fusion protein was obtained successfully and the UL7 protein-specific polyclonal antibody was pre-pared. Accompany with the proliferation of HSV-1, the expression of UL7 protein was detected at different time points by using the polyclonal antibody.

A Meta-analysis of the incidence of influenza reported during year 2005 to 2012 in China / 中华微生物学和免疫学杂志

Objective To investigate the epidemic patterns and the characteristics of influenza in Chi-na through a Meta-analysis based on the studies published in domestic literatures.Methods Related articles published during 2005 to 2012 were screened out from domestic databases and analyzed through a Meta-analysis with Review Manager 5.0 software.Results Twenty-two articles covering 957 901 patients with influenza-like-illness (ILI) and 148 233 pathogen samples were screened out according to the inclusion criteria.No significant difference with the ILI diagnosis rate was found between subjects at age 0-4 years and those at age 15-59 years. Higher ILI diagnosis rates were observed in those two groups as compared with subjects elder than 60 years old. Most of the pathogen samples were carried by subjects aged 25-59 years.More influenza virus strains were isola-ted in 2009 as compared with those of the seven other years (OR=2.25, 95%CI=1.27-3.70).There was sta-tistical difference between the numbers of influenza A H1N1 and seasonal influenza A strains (OR=2.25, 95%CI=1.30-3.91) .Significant difference was also observed between the numbers of influenza A and influenza B strains (OR=4.05, 95%CI=2.53-6.47).Conclusion There was significant difference with the diagnosis rate between subjects aged 0-4 years and those aged≥60 years.More attention should be paid to people at high risk of infection (0-4 years old and≥60 years old) and those at 25-29 years with high mobility and social inter-course for the timely prevention and control of pandemic influenza.The detection rate of influenza virus strains was increased during the outbreak of novel influenza A H1N1 infection in 2009.After that outbreak, the detec-tion rate of novel influenza A H1N1 strains was 2.25 times the rate of seasonal influenza strains.The detection rate of influenza A was 4.05 times the rate of influenza B virus strains.Therefore, it is necessary to strengthen the surveillance for influenza A virus and other epidemic influenza virus strains.