title: Alkylating agent melphalan augments the efficacy of adoptive immunotherapy using tumor-specific CD4+ T cells.
abstract: In recent years, the immune-potentiating effects of some widely used chemotherapeutic agents have been increasingly appreciated. This provides a rationale for combining conventional chemotherapy with immunotherapy strategies to achieve durable therapeutic benefits. Previous studies have implicated the immunomodulatory effects of melphalan, an alkylating agent commonly used to treat multiple myeloma, but the underlying mechanisms remain obscure. In the present study, we investigated the impact of melphalan on endogenous immune cells as well as adoptively transferred tumor-specific CD4(+) T cells in tumor-bearing mice. We showed that melphalan treatment resulted in a rapid burst of inflammatory cytokines and chemokines during the cellular recovery phase after melphalan-induced myelodepletion and leukodepletion. After melphalan treatment, tumor cells exhibited characteristics of immunogenic cell death, including membrane translocation of the endoplasmic reticulum-resident calreticulin and extracellular release of high-mobility group box 1. Additionally, there was enhanced tumor Ag uptake by dendritic cells in the tumor-draining lymph node. Consistent with these immunomodulatory effects, melphalan treatment of tumor-bearing mice led to the activation of the endogenous CD8(+) T cells and, more importantly, effectively drove the clonal expansion and effector differentiation of adoptively transferred tumor-specific CD4(+) T cells. Notably, the combination of melphalan and CD4(+) T cell adoptive cell therapy was more efficacious than either treatment alone in prolonging the survival of mice with advanced B cell lymphomas or colorectal tumors. These findings provide mechanistic insights into melphalan's immunostimulatory effects and demonstrate the therapeutic potential of combining melphalan with adoptive cell therapy utilizing antitumor CD4(+) T cells.
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Division of Digestive Endoscopy, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing 210029, China;
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Lu
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Zhi-Chun
authors.initials: ZC
authors.lastname: Ding
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China;
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Department of Orthodontics, Guangdong Provincial Stomatological Hospital, Southern Medical University, Guangzhou 510280, China;
authors.forename: Chufeng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Tsadik
authors.initials: T
authors.lastname: Habtetsion
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Henrique
authors.initials: H
authors.lastname: Lemos
authors.affiliation: Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; and.
authors.forename: Huda
authors.initials: H
authors.lastname: Salman
authors.affiliation: Department of Biostatistics and Epidemiology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Xu
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; and.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Mellor
authors.affiliation: Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; and gzhou@gru.edu.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage*; D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000637:transplantation*; D003131:Combined Modality Therapy; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016219:Immunotherapy, Adoptive / Q000379:methods*; D008558:Melphalan / Q000008:administration & dosage*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D009374:Neoplasms, Experimental / Q000628:therapy*
chemical_list: D018906:Antineoplastic Agents, Alkylating; D008558:Melphalan