Detection of HPV Types and Neutralizing Antibodies in Women with Genital Warts in Tianjin City,China

The serum samples and corresponding cervical swabs were collected from 50 women with genital warts from Tianjin city,China.The neutralizing antibodies against HPV-16,-18,-58,-45,-6 and-11 in serum samples were tested by using pseudovirus-based neutralization assays and HPV DNAs in cervical swabs were also tested by using a typing kit that can detect 21 types of HPV.The results revealed that 36%(18/50)of sera were positive for type-specific neutralizing antibodies with a titer range of 160-2560,of which 22%(11/50),12%(6/50), 10%(5/50),4%(2/50),4%(2/50)and 2%(1/50)were against HPVs-6,-16,-18,-58,-45 and-11,respectively. Additionally,60%(30/50)of samples were HPV DNA-positive,in which the most common types detected were HPV-68(18%),HPV-16(14%),HPV-58(12%),HPV-33(8%)and HPV-6,HPV-11,HPV-18 and HPV-52(6% each).The concordance between HPV DNA and corresponding neutralizing antibodies was 56%(28/50)with a significant difference(P<0.05).The full-length sequences of five HPV types(HPV-42,-52,-53,-58 and-68) were determined and exhibited 98%-100%identities with their reported genomes.The present data may have utility for investigating the natural history of HPV infection and promote the development of HPV vaccines.

Comparison of the Immunogenicities of HIV-1 Mutants Based on Structural Modification of env

Eleven env mutants were designed and generated by site-directed mutagenesis of the regions around NAb epitopes and deletions of variable regions in env. The immunogenicities of the generated mutants were evaluated using single-cycle infection neutralization assays with two pseudoviruses and IFN-γ ELISPOT. Overall, five mutants (dWt, M2, M5-2, M5-1 and dM7) induced higher neutralization activities for both pseudoviruses than plasmid Wt, while only two of the mutants (dWt and M5-2) showed significant differences (P<0.05). Two mutants (M2 and dM2) induced more Env-specific T cells than plasmid Wt. Statistically however, significance was only reached for mutant M2. Thus, properly modified HIV-1 Env may have the potential to induce potent cellular and humoral immune responses.

Preliminary Study on a Potential Panel for Quality Assurance of ELISPOT

The ELISPOT assay is increasingly used for assessing cellular immune responses in clinical trials of HIV-1 or cancer vaccines. However, to date, data from clinical trials do not consistently show that immune responses are correlated with clinical endpoints. This is due in part to the lack of assay standardization and validation across laboratories and therefore, a quality control panel is required to establish competency and comparability amongst different laboratories. In this study peripheral blood mononuclear cells (PBMCs) from healthy individuals were screened and frozen in liquid nitrogen. The recovery and viability of the PBMCs and the frequencies of interferon (IFN)-γ-secreting cells after CEF peptide pool stimulation were detected after various intervals in seven different laboratories. The recovery and viability did not differ significantly after different intervals. Although the frequencies of IFN (interferon)-γ-secreting cells among thawed PBMCs (peripheral blood mononuclear cells) fluctuated after CEF peptide pool stimulation at different intervals, they were not significantly decreased compared with those among fresh PBMCs. However, the viabilities, recoveries and frequencies of IFN-γ-secreting cells differed significantly among the seven laboratories. Our results indicate that cryopreserved PBMCs could be used as a quality control panel for ELISPOT. However, the procedures for ELISPOT need to be standardized amongst different laboratories.

Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development

To discover new drugs to combat COVID-19,an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed.Here,for the first time,we report the crucial role of cathepsin L(CTSL)in patients with COVID-19.The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity.Correspondingly,SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo,while CTSL overexpression,in turn,enhanced pseudovirus infection in human cells.CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry,as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo.Furthermore,amantadine,a licensed anti-influenza drug,significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo.Therefore,CTSL is a promising target for new anti-COVID-19 drug development.