ABSTRACT
Golden (Syrian) hamster (Mesocricetus auratus) is a small animal model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Pathological analyses of the tissues are required to understand the pathogenesis of SARS-CoV-2 and the evaluation of therapeutic modalities, including neutralizing monoclonal antibodies (mAbs). However, mAbs that recognize the golden hamster-derived antigens and distinguish specific cell types, such as the pneumocytes, are limited. Podoplanin (PDPN) is an essential marker of lung type I alveolar epithelial cells, kidney podocytes, and lymphatic endothelial cells. In this study, an anti-Chinese hamster (Cricetulus griseus) PDPN mAb PMab-281 (IgG3, kappa) was established using the Cell-Based Immunization and Screening (CBIS) method. A defucosylated mouse IgG2a version of PMab-281 (281-mG2a-f) was also developed. The 281-mG2a-f strongly recognized both the Chinese hamster and the golden hamster PDPN using flow cytometry and could detect lung type I alveolar epithelial cells, lymphatic endothelial cells, and Bowman's capsules in the kidney from the golden hamster using immunohistochemistry. These results suggest the usefulness of 281-mG2a-f for analyzing the golden hamster-derived tissues and cells for SARS-CoV-2 research.
ABSTRACT
The CC chemokine receptor type-2 (CCR2) is one of the members of the G protein-coupled receptor superfamily, which are expressed on the cell surface of immune and tumor cells. CCR2 binds to the C-C motif chemokine ligand 2 (CCL2)/monocyte chemoattractant protein-1 (MCP-1), which is produced by various cells, including tumor and immune-related cells. Therefore, the development of sensitive monoclonal antibodies (mAbs) for CCR2 has been desired for treatment and diagnosis. In this study, we established a specific antihuman CCR2 (hCCR2) mAb, C2Mab-9 (mouse IgG1, kappa), using the synthetic peptide immunization method. Flow cytometric and immunocytochemical results showed that C2Mab-9 reacted with hCCR2-expressing U937 (human histiocytic lymphoma) and natural killer cells. Furthermore, C2Mab-9 showed the moderate binding affinity for both cells. Conclusively, C2Mab-9 can be a useful tool for analyzing hCCR2-related biological responses.
Subject(s)
Antibodies, Monoclonal , Receptors, CCR2 , Animals , Immunization , Mice , PeptidesABSTRACT
BACKGROUND: Hospital workers are at high risk of COVID-19 infection which is now vaccine-preventable. However, vaccine refusals also occur among hospital workers, but the associated factors have not been described. OBJECTIVES: To describe: (1) the level of COVID-19 vaccine acceptance, and; (2) the extent that history of pre-pandemic vaccine hesitancy and health beliefs regarding COVID-19 were associated with COVID-19 vaccine acceptance among workers at a tertiary hospital in southern Thailand. METHODS: We conducted a cross-sectional study using a paper-based self-administered questionnaire at a tertiary hospital in south Thailand in April 2021 and used multivariable logistic regression to identify psychological-behavioral factors associated with vaccine acceptance. RESULTS: Of 359 workers invited to participate, 226 participants returned the questionnaires, 67% of whom reported willingness to accept the vaccine. Vaccine acceptance was associated with perceived severity of disease (Adjusted OR = 2.07, 95% CI = 1.04, 4.10), perceived harm from non-vaccination (Adjusted OR = 2.51, 95% CI = 1.27, 4.96), and lower expectation of vaccine efficacy (Adjusted OR = 3.80, 95% CI = 1.87, 7.71). CONCLUSION: Most workers in this study were willing to accept the COVID-19 vaccine, and such acceptance was associated with components of the health belief model. However, the cross-sectional study design did not allow causal inference, and study data were all self-reported with no probing of the responses. These limitations should be considered as caveats in the interpretation of the study findings.