{'fraction_non_alphanumeric': 0.02987012987012987, 'fraction_numerical': 0.013852813852813853, 'mean_word_length': 5.049738219895288, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Function analysis of the family-specific CTL induced by peptides derived from IgHV gene framework region of B-cell malignance].

OBJECTIVE
To identify immune epitopes existed in the framework region (FR) of the IgHV protein of B-cell malignance, and explore the use of these FR-derived peptides to induce the family specific immune response in vitro, in order to explore the possibility of a new IgHV gene family-specific immunotherapy for B-cell malignance.


METHODS
Bioinformatics was used for predicting T cell epitopes in IgHV protein. Peptides of interest were synthesized in vitro. T2 cell binding assay was performed to determine the binding ability of the peptides to HLA-A*0201 molecules. Peptide/HLA tetramer staining was used to detect the number of peptide-specific cytotoxic T lymphocytes (CTLs). Cytotoxicity assay was used to determine killing activity.


RESULTS
Twelve peptides that were common to seven IgHV gene subfamilies were identified, and 10 (83%) of them were located in the FR of IgHV protein. The synthesized peptides up-regulated HLA*0201 molecules fluorescence intensity on cell surfaces of T2. By using an antigen-specific T-cell expansion system in vitro, the peripheral blood mononuclear cells (PBMNC) from a healthy HLA-A0201 donor were stimulated weekly by autologous PBMNC loaded with the peptide as antigen presenting cells (APC), and the peptide-specific CTLs were demonstrated to be generated successfully in the healthy donors. The frequency of CD8 and peptide/HLA tetramer double positive cells in the gated lymphocyte population was 0.38% before stimulation and increased to 49.38 % after four times stimulation. Cytotoxicity assay indicated that these CTLs were capable of killing the HLA-A*0201, IgHV1 (+) lymphoma cells. Furthermore, the generated CTL could not kill the target cell loaded with the IgHV3 peptide, indicating that the cytotoxicity is family-specific.


CONCLUSION
Peptides derived from the IgHV protein FR can successfully induce the generation of peptide-specific CTLs in vitro. These CTLs are capable of killing the lymphoma cell belonged to the same subfamily in a peptide-specific and MHC-restricted way. These findings could potentially form the basis of broadening application of immunoglobulin-directed immunotherapy in B-cell malignancies.