Identification of novel HLA-A∗0201-restricted CTL Epitopes from Pokemon

Role of ZBTB7A zinc finger in tumorigenesis and metastasis

The zinc finger and BTB (broad-complex, tramtrack and bric a brac) domain containing protein 7A (ZBTB7A) is a pleiotropic transcription factor that plays an important role in various stages of cell proliferation, differentiation, and other developmental processes. ZBTB7A is a member of the POK family that directly and specifically binds to short DNA recognition sites located near their target genes thereby acting as transcriptional activator or repressor. ZBTB7A overexpression has been associated with tumorigenesis and metastasis in various human cancer types, including breast, prostate, lung, ovarian, and colon cancer. However in some instances downregulation of ZBTB7A results in tumor progression, suggesting its role as a tumor suppressor. ZBTB7A is involved with complicated regulatory networks which include protein-protein and protein-nucleic acid interactions. ZBTB7A involvement in cancer progression and metastasis is perhaps enabled through the regulation of various signaling pathways depending on the type and genetic context of cancer. The association of ZBTB7A with other proteins affects cancer aggressiveness, therapeutic resistance and clinical outcome. This review focuses on the involvement of ZBTB7A in various signaling pathways and its role in cancer progression. We will also review the literature on ZBTB7A and cancer which could be potentially explored for its therapeutic implications.

Identification of HLA-A*0201-restricted CTL Epitopes for MLAA-34-specific Immunotherapy for Acute Monocytic Leukemia

Our previous research has shown that monocytic leukemia-associated antigen-34 (MLAA-34) was a novel antiapoptotic molecule with unique expression in acute monocytic leukemia (M5), making it an ideal target for T-cell-based immunotherapy. Here, we sought to identify HLA-A*0201-restricted cytotoxic T-lymphocyte (CTL) epitope of MLAA-34 by reverse immunology. In all, 10 HLA-A*0201 restricted epitopes of MLAA-34 were predicted by bioinformatics. MLAA-34324-332, MLAA-34293-301, and MLAA-34236-244 showed the strongest HLA-A*0201-binding affinity. The percentages of HLA-A*0201-MLAA-34236-244 tetramer+ CD8+ T cells in MLAA-34236-244-induced CTLs were raised apparently. Enzyme-linked immunospot showed that MLAA-34236-244 and MLAA-34324-332-specific CTLs produced a higher amount of interferon-γ. MLAA-34236-244-induced CTLs presented a stronger cytotoxic effect on THP-1 cells (HLA-A*0201+MLAA-34+) at various effector to target ratios. MLAA-34236-244 peptide vaccine could inhibit the tumor growth and improve mean survival time of leukemia-bearing human peripheral blood lymphocyte reconstituting severe combined immunodeficient mice. Mice immunized with MLAA-34236-244 vaccine had increased percentages of MLAA-34236-244 tetramer+ CD8+ T cells in the spleen after each round of immunization. High-purity CD8+ and CD4+ T cells were sorted by Dynabeads as effector cells. The killing activity of CD8+ T cells was higher than that of CD4+ T cells. CTLs derived from the MLAA-34 peptide vaccine group were significantly higher than other therapeutic groups and showed specific cytotoxicity to THP-1 cells. Increased interferon-γ and interleukin (IL)-2 and decreased IL-10 and IL-4 were seen in the MLAA-34236-244 peptide vaccine group. MLAA-34236-244 peptide (ILDRHNFAI) is an effective HLA-A*0201-restricted CTL epitope and that it may serve as a promising strategy in designing antigen-specific immunotherapy against MLAA-34-positive acute monocytic leukemia.

Emerging role of ZBTB7A as an oncogenic driver and transcriptional repressor

ZBTB7A is a member of the POK family of transcription factors that possesses a POZ-domain at the N-terminus and Krüppel-like zinc-finger at the c-terminus. ZBTB7A was initially isolated as a protein that binds to the inducer of the short transcript of HIV-1 virus TAT gene promoter. The protein forms a homodimer through protein-protein interaction via the N-terminus POZ-domains. ZBTB7A typically binds to the DNA elements through its zinc-finger domains and represses transcription both by modification of the chromatin organization and through the direct recruitment of transcription factors to gene regulatory regions. ZBTB7A is involved in several fundamental biological processes including cell proliferation, differentiation, and development. It also participates in hematopoiesis, adipogenesis, chondrogenesis, cellular metabolism and alternative splicing of BCLXL, DNA repair, development of oligodendrocytes, osteoclast and unfolded protein response. Aberrant ZBTB7A expression promotes oncogenic transformation and tumor progression, but also maintains a tumor suppressive role depending on the type and genetic context of cancer. In this comprehensive review we provide information about the structure, function, targets, and regulators of ZBTB7A and its role as an oncogenic driver and transcriptional repressor in various human diseases.

Metadherin peptides containing CD4(+) and CD8(+) T cell epitopes as a therapeutic vaccine candidate against cancer

The concept of peptide-based vaccines against cancer has made noteworthy progress. Metadherin (MTDH) overexpression and its role in the development of diverse cancers make it an attractive target for cancer immunotherapy. In the current study, six different T cell epitope prediction tools were run to identify MTDH peptides with multiple immunogenic regions. Further, molecular docking was performed to assess HLA-peptide binding interactions. Nine and eleven peptides fragments containing multiple CD8 (+) and CD4 (+) T-cell epitopes, ranging from 9 to 20 amino acids, respectively, were obtained using a consensus immunoinformatics approach. The three peptides that were finally identified as having overlapping CD4 (+) and CD8 (+) T- cell epitopes are ARLREMLSVGLGFLRTELG, FLLGYGWAAACAGAR, YIDDEWSGLNGLSSADP. These peptides were found to not only have multiple T cell epitopes but also to have binding affinity with wide HLA molecules. A molecular docking study revealed that the predicted immunogenic peptides (with single or multiple T cell epitopes) of MTDH have comparable binding energies with naturally bound peptides for both HLA classes I and II. Thus, these peptides have the potential to induce immune responses that could be considered for developing synthetic peptide vaccines against multiple cancers.