Abstract
BackgroundMyeloma cells retain B cell functions, considered to be potential antigen presenting cells, yet there is little information regarding promoting Th2 cell proliferation or the direct effects to myeloma on the Th2 cells stimulated by microbial antigens-loaded myeloma cells.MethodsMixed lymphocyte reaction was used colorimetric assays via CCK8-kit. Surface molecular expression was performed by flow cytometry, cells sorting using microbeads. The concentrations of cytokines in serum were assessed using an ELISA kit. Clonogenic assay were performed in a methylcellulose culture system. Statistical analysis was assessed using the Student’s t-test or one-way analysis of variance for multiple comparisons test.ResultsThe expression of HLA-DR, CD80 and CD40 on RPMI8266 cell membrane surface was upregulated by interaction with interferon-γ and/or Bacillus Calmette-Guerin Vaccine (BCGV). RPMI8266 cells were able to induce the mixed lymphocyte reaction in a dose-dependent fashion. The Th2 ratio induced by RPMI8266 treated by BCGV and interferon-γ (treated-RPMI8266) cells was only slightly greater than by untreated-tumor cells, but the serum IL-4 level secreted by Th2 cells was markedly higher in treated-RPMI8266 cells group. Th2 cells stimulated by treated-myeloma cells could directly promote treated-myeloma cell clonogenicity in a dose-dependent manner. Anti-HLADR IgG2b completely blocked increased of IL-4 secretion by Th2 cells stimulated by treated-myeloma cells, while also blocked enhancing the clonogenicity of treated tumor cells stimulated by MM-Th2 cells.ConclusionsThese results indicate that a novel mechanism of myeloma pathogenesis in myeloma cells could act as an APC to present microbial Ags to Th2 cells, promoting Th2 cell proliferation, consequently facilitating tumor development by close interaction between Th2 myeloma cells. Taken together, the microbial Ag presenting course of MM-Th2-MM interactions—restricted by MHC class-II—may result in tumor development such that all factors involved in the system could have a potential for myeloma therapeutic intervention.
Highlights
Myeloma cells retain B cell functions, considered to be potential antigen presenting cells, yet there is little information regarding promoting Th2 cell proliferation or the direct effects to myeloma on the Th2 cells stimulated by microbial antigens-loaded myeloma cells
Mixed lymphocyte reaction (MLR) We used the RPMI8226 multiple myeloma (MM) cell line as a model system to investigate whether MM cells are capable of presenting microbial antigens to T cells via MHC II, and whether that affects the response to T cells to MM cells in a mixed lymphocyte reaction
MLR of RPMI8266 cells In order to assess the presentation of antigen to T cells by RPMI8266 cells, MLR was performed after RPMI8266 cells were treated with IFN-γ and Bacillus Calmette-Guerin Vaccine (BCGV) for 48 h
Summary
Myeloma cells retain B cell functions, considered to be potential antigen presenting cells, yet there is little information regarding promoting Th2 cell proliferation or the direct effects to myeloma on the Th2 cells stimulated by microbial antigens-loaded myeloma cells. Multiple myeloma (MM) is a B cell tumor that is characterized by the clonal expansion of malignant plasma cells in bone marrow [1]. Interactions involving stromal cells, as well as B- and plasma cell differentiation and growth factors—such as IL-6, BAFF and RANK—have been implicated in the development of MM [4,5,6,7]. Prior studies have demonstrated that heavy infiltration of human tumors by Dendritic cells (DCs), or polarization of Th2 cells in peripheral blood, is often correlated with an adverse prognosis [8,9,10,11,12,13,14,15,16]. Several studies have reported that Th2 cells have been confirmed to promote MM growth though myeloma cell-Th2 cell interactions [11, 17, 18]. Antigenpresenting cells (APCs), for example DCs, and Th2 cells might play an important key in MM development
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
