Dendritic cells pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma induce specific anti-tumor immune responses

AIM： To investigate the anti-tumor effect of dendritic cells （DCs） pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma （HCC） cells on human T cells. METHODS： Hsp70-peptide complexes were purified from human HCC cells with column chromatography using ADP-agarose and DEAE-Sepharose. DCs were derived from peripheral blood mononuclear cells of healthy donors in the presence of human GM-CSF and IL-4. The anti-tumor effect of DCs pulsed with hsp70-peptide complexes on human T-cell was assayed by CTL and enzyme-linked immunospot （ELISPOT） tests. RESULTS： Hsp70-peptide complexes derived from human HCC cells activated phenotypic and functional maturation of DCs. The matured DCs stimulated a high level of autologous T-cell proliferation and type Ⅰ cytokine secretion, and induced HCC-specific cytotoxic T lymphocytes （CTLs）, which specifically killed HCC cells by a MHC class Ⅰ restricted mechanism. CONCLUSION： Hsp70-peptide complexes derived from human HCC cells can serve as a potent tumor antigen source for pulsing DCs, the pulsed DCs are very effective in activating specific T-cell responses against HCC cells. 2005 The WJG Press and Elsevier Inc. All rights reserved

An adjusted ELISpot-based immunoassay for evaluation of SARS-CoV-2-specific T-cell responses

Like antibody evaluation,using an effective antigen‐specific T‐cell immunity assessment method in coronavirus disease 2019(COVID‐19)patients,survivors and vaccinees is crucial for understanding the immune persistence,prognosis assessment,and vaccine development for COVID‐19.This study evaluated an empirically adjusted enzyme‐linked immunospot assay for detecting severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)‐specific T‐cell immunity in 175 peripheral blood samples from COVID‐19 convalescents and healthy individuals.Results of viral nucleic acid were used as the gold standard of infection confirmation.The SARS‐CoV‐2M peptide pool had higher sensitivity of 85%and specificity of 71%for the single peptide pool.For combined peptide pools,the parallel evaluation(at least one of the peptide pools is positive)of total peptide pools(S1&S2&M&N)had higher sensitivity(up to 93%),and the serial evaluation(all peptide pools are positive)of total peptide pools had higher specificity(up to 100%).The result of the serial evaluation was better than that of the parallel evaluation as a whole.The detection efficiency of M and N peptide pool serial evaluation appeared the highest,with a sensitivity of 80%and specificity of 93%.This T‐cell immunity detection assay introduced in this report can achieve high operability and applicability.Therefore,it can be an effective SARS‐CoV‐2‐specific cellular immune function evaluation method.