Coinfusion of irradiated splenocytes with low titer tumor-infiltrating lymphocytes augments antitumor efficacy in adoptive immunotherapy

Personal Neoantigens From Patients With NSCLC Induce Efficient Antitumor Responses

Objective

To develop a neoantigen-targeted personalized cancer treatment for non-small cell lung cancer (NSCLC), neoantigens were obtained from collected human lung cancer samples, and the utility of neoantigen and neoantigen-reactive T cells (NRTs) was assessed.

Methods

Tumor specimens from three patients with NSCLC were obtained and analyzed by whole-exome sequencing, and neoantigens were predicted accordingly. Dendritic cells and T lymphocytes were isolated, NRTs were elicited and IFN-γ ELISPOT tests were conducted. HLA-A2.1/K^b transgenic mice were immunized with peptides from HLA-A*02:01⁺patient with high immunogenicity, and NRTs were subjected to IFN-γ, IL-2 and TNF-α ELISPOT as well as time-resolved fluorescence assay for cytotoxicity assays to verify the immunogenicity in vitro. The HLA-A*02:01⁺lung cancer cell line was transfected with minigene and inoculated into the flanks of C57BL/6^nu/nu mice and the NRTs induced by the immunogenic polypeptides from autologous HLA-A2.1/K^b transgenic mice were adoptively transfused to verify their immunogenicity in vivo.

Results

Multiple putative mutation-associated neoantigens with strong affinity for HLA were selected from each patient. Immunogenic neoantigen were identified in all three NSCLC patients, the potency of ACAD8-T105I, BCAR1-G23V and PLCG1-M425L as effective neoantigen to active T cells in suppressing tumor growth was further proven both in vitro and in vivo using HLA-A2.1/Kb transgenic mice and tumor-bearing mouse models.

Conclusion

Neoantigens with strong immunogenicity can be screened from NSCLC patients through the whole-exome sequencing of patient specimens and machine-learning-based neoantigen predictions. NRTs shown efficient antitumor responses in transgenic mice and tumor-bearing mouse models. Our results indicate that the development of neoantigen-based personalized immunotherapies in NSCLC is possible.

Precis

Neoantigens with strong immunogenicity were screened from NSCLC patients. This research provides evidence suggesting that neoantigen-based therapy might serve as feasible treatment for NSCLC.

Antitumor effects of Flt3 ligand in transplanted murine tumor models

Administration of Flt3 ligand (FL) to mice causes dendritic and natural killer cells to increase but certain solid tumors to regress. Depending on the particular tumor model used, T cells and natural killer cells have been implicated in the protective immune response induced by FL. The current study examined the effects of FL administration on tumor establishment and progression in metastatic and primary tumor models to correlate anatomic location with immunotherapeutic efficacy. FL mediated significant (p < or = 0.05) therapeutic activity against pulmonary metastases of the murine MC-38 colon adenocarcinoma, particularly when cytokine administration was initiated before tumor inoculation. However, progressive intraabdominal tumors sometimes were observed even in the relative absence of pulmonary metastases. Significant, although less dramatic, antimetastatic effects were observed with MCA-205 and MCA-102 sarcomas and D5 (B16BL6) melanoma. In contrast, FL was ineffective against subcutaneous MC-38 tumors or against several intracranial tumors. This suggests that besides the administration dose, the efficacy of this cytokine depends on the tumor type and possibly the location of the inoculated tumor. Antitumor activities of FL were abolished by whole-body irradiation (500 cGy) and partially abolished by systemic depletion of CD8, CD4, or natural killer cells. The results indicate that optimization of FL immunotherapy of tumors will require a firmer understanding of the relative contributions of tumor burden, location, immune system requirements, and other factors.