Mutual helper effect in copulsing of dendritic cells with 2 antigens: a novel approach for improvement of dendritic-based vaccine efficacy against tumors and infectious diseases simultaneously

Cell separation: Potentials and pitfalls

Cell separation techniques play an indispensable part in numerous basic biological studies and even clinical settings. Although various cell isolation methods with diverse applications have been devised so far, not all of them have been able to gain widespread popularity among researchers and clinicians. There is not a single method known to be advantageous over all cell isolation techniques, and in fact, it is the researcher's aim in performing a study that determines the most suitable method. A perfect method for one study might not be necessarily a proper choice for another and likewise, expensive and complex isolation methods might not always be the best choices. There are several criteria such as cell purity, viability, activation status, and frequency that need to be given serious thought before selecting an isolation technique. Moreover, time and cost are two of the key elements that should be taken into consideration before implementing a project. Hence, here we provide a succinct description of six more popular cell separation methods with respect to their principles, advantages, and disadvantages as well as their most common applications. We further provide several key features of each technique so that it helps the researchers to take the first step toward opting for the best method that fits well into their projects.

Improved Efficacy of a Dendritic Cell-Based Vaccine against a Murine Model of Colon Cancer: The Helper Protein Effect

Purpose

Targeted immunotherapy using dendritic cells (DCs) has been employed in numerous investigations aiming at combating neoplasms. We previously showed that copulsing of an antigen with a helper protein could considerably enhance antigen presenting capacity of ex vivo–generated DCs. In this study, we attempted to administer an effective treatment in a murine model of colon cancer with DCs pulsed with the mixture of a tumor-specific gp70-derived peptide (AH1) and a helper protein, ovalbumin (OVA).

Materials and Methods

First, the presence of gp70 in CT26 tumor cells and tumor tissues was verified using immunofluorescence and Western blot analyses. Next, DCs were purified from normal mice, loaded ex vivowith AH1 and OVA (DC-Pep-OVA), and injected into tumor-bearing mice. Tumor volume, in vitro antigen (Ag)-specific proliferation of splenic cells, and survival rate were measured to determine the efficacy of DC-Pep-OVA. As the control groups, tumor-bearing mice were vaccinated with DC-Pep, unpulsed DC, and DCs loaded with a mixture of OVA and an irrelevant peptide (P15), or were not vaccinated at all.

Results

DC-Pep-OVA showed superior efficacy over other groups, as indicated by smaller tumor volume, higher Ag-specific proliferation rate of splenic cells, and prolonged survival.

Conclusion

Overall, in the present study we showed for the first time that DCs copulsed with AH1 (tumor Ag) and OVA (helper molecule) could be considered as potentially robust weapons for use in future antitumor immunotherapies.

Enhanced immunity against hepatoma induced by dendritic cells pulsed with Hsp70-H22 peptide complexes and CD40L

PURPOSE

Dendritic cell (DC)-based cancer vaccines have become an attractive antitumour therapeutic approach. However, clinical application of current DC-based cancer vaccines has been limited by their ineffectiveness. Heat shock protein 70 from Mycobacterium tuberculosis (TBhsp70) is known to have a potent adjuvant capability to induce maturation of DCs and thus acts as an alternative ligand to the CD40 ligand (CD40L) on T cells to induce a T-cell response. The aim of this study is to investigate whether the combination of TBhsp70-H22 tumour-peptide complexes and CD40L might improve the antitumour efficacy for development of therapeutic DC-based vaccines against hepatoma.

METHODS

The CD40, CD80, CD86 and HLA-DR expression on DCs pulsed with TBhsp70-H22 tumour-peptide complexes and soluble CD40L was studied by flow cytometric analysis, and T-helper type 1 cytokine secretion, such as IL-12p70 secretion, was tested by ELISA. The H22-specific cytotoxic T-lymphocytes (CTLs) were detected by a (51)Cr-release assay, and the in vivo antitumour immunity against hepatoma was measured by utilising H22-tumour-bearing mice after therapeutic administration.

RESULTS

Up-regulation of CD40, CD80, CD86 and HLA-DR expression on DCs pulsed with TBhsp70-H22 tumour-peptide complexes and CD40L was found, which stimulated a high level of T-helper type 1 cytokine secretion, such as IL-12p70, and resulted in the induction of H22-specific CTLs. The therapeutic administration of DCs pulsed in vitro with TBhsp70-H22 tumour-peptide complexes and CD40L significantly reduced the progression of H22 tumours in mice compared with DC-Hsp70-H22 peptide complexes or DC-CD40L alone.

CONCLUSIONS

Our findings demonstrate that DCs pulsed with Hsp70-H22-peptide complexes and CD40L enhance the antitumour immunity against hepatoma, which provides a novel immunotherapeutic approach against cancer.

Effects of 1,25(OH)2 vitamin D3 on cytokine production by endometrial cells of women with recurrent spontaneous abortion

OBJECTIVE

To investigate immunomodulatory effect of 1,25(OH)2 vitamin D3 (1,25(OH)2D3) on cytokine production by endometrial cells of women with unexplained recurrent spontaneous abortion (URSA).

DESIGN

In vitro study.

SETTING

Academic research center.

PATIENT(S)

Patients with URSA and healthy controls.

INTERVENTION(S)

Treatment with 1,25(OH)2D3.

MAIN OUTCOME MEASURE(S)

Production of interferon γ (IFN-γ), interleukin-10 (IL-10), transforming growth factor β (TGF-β), IL-17, IL-6, and IL-8 by whole endometrial cells (WECs) and endometrial stromal cells in the presence and absence of 1,25(OH)2D3 and 1α-hydroxylase activity of these cell populations were measured in patients with URSA and healthy controls.

RESULT(S)

1,25(OH)2D3 interfered with production of cytokines by WECs of the control and URSA groups, except IL-8 which was increased in URSA group. In endometrial stromal cells, 1,25(OH)2D3 down-regulated cytokine production as well with stimulatory effect on the production of TGF-β in patients with URSA. Cytokine profile of WECs from patients with URSA skewed toward TH2 phenotype after treatment with 1,25(OH)2D3. Endometrial cells of both groups had comparable capacity to produce 1,25(OH)2D3.

CONCLUSION(S)

Considering the complex network of immunoregulation at the fetomaternal interface, potential beneficial effects of vitamin D3 in patients with URSA need to be investigated in clinical practice. Comparable levels of 1,25(OH)2D3 production and similar trend of cytokine expression by WECs of URSA and control groups after vitamin D3 treatment reflect the same local metabolic machinery of this hormone.

Potentiation strategies of dendritic cell-based antitumor vaccines: combinational therapy takes the front seat

Despite recent attempts to take advantage of dendritic cell (DC)-based vaccines for cancer immunotherapy, the results of clinical studies have been disappointing. This is mainly as a result of the diverse immune escape mechanisms used by the tumor together with the insufficient ability of DCs to mount an effective immune response against these mechanisms. In this regard, several approaches have been devised to improve the efficacy of DC-based vaccines. However, the application of each individual approach per se might not be sufficient to overwhelm the diverse immune escape mechanisms. In this review, we focus on current strategies for the ex vivo potentiation of DC-based vaccines, with an emphasis on combinational therapy methods as a promising alternative for tumor immunotherapy.