Dendritic cells

Fighting cancer with the help of the immune system is one of the central components of every alternative or homeopathic method of treating tumours. Some of the most important types of therapy are, for example, hyperthermia, active fever therapy or treatment with mistletoe or thymus extracts, just to name a few. A method that has been more and more in the limelight in the past years due to national and international studies is the inoculation with so-called dendritic cells.

What are dendritic cells?

Dendritic cells are also called the immune system’s patrol cells or alarm raisers. Together with macrophages, monocytes and B-lymphocytes they belong to the group of so-called antigen presenting cells in the immune system. The tasks of the dendritic cells include absorbing materials foreign to the body (antigens), which they then use to make other immune cells, the T cells, aware of antigens in the body. This in turn causes an immune reaction in the T cells. The cells that have been activated like this make their way to the diseased tissue and destroy the foreign substances that have pervaded the body. This is exactly the mechanism that the therapeutic inoculation against cancer makes use of.

The production of dendritic cells

In order to produce dendritic cells, monocytes (a sub-group of the white blood cells) are isolated from the patient’s blood. These are then treated with various growth factors so that dendritic cells develop within about 7 days. Then the dendritic cells are ‘fed’ under laboratory conditions with cancer cells and their antigens, which have been extracted from the surgically removed tumour. During this process the dendritic cells absorb the cancer cells and become loaded with antigens.

Before the dendritic cells are injected into the patient’s body they must be intensively examined for virus infections, bacteria, fungi and residues from the production process. They may not be injected into the patient’s body until they are absolutely clean, which is established through exact molecular-biological analysis. The patient receives an inoculation at least four times every four weeks.

The effect of the dendritic cells

The dendritic cells injected into the patient’s body wander to the central lymph areas. Then an exchange of cell information takes place, upon which the lymphocytes are activated. These cells recognise the tumour cells as a foreign substance in the body and attack them. The aim of this therapy is to make the tumour grow more slowly until it stops growing altogether, if possible – ideally it can even make the tumour regress.

The best time for an inoculation is immediately after the tumour has been surgically removed, i.e. when the tumour is the least burden to the body. In this situation the immune system can generate an effective response to recurring tumour cells. Furthermore, active memory cells are created in this process, which increase the chance of slowing down the growth of the tumour or decreasing its size. Treatment with dendritic cells has the advantage that there are only very minor side effects or none at all.
The successes with this therapy are quite encouraging. Studies in the United States show, for example, that approx. 30 percent of patients with prostate gland carcinomas treated with dendritic cell inoculations are still alive after three years, even in seemingly hopeless cases. At the same time, there was an improvement in these patients’ overall physical condition. Only about 10 percent of the patients in the control group, who did not receive this treatment, were still alive after the same time span.

Dendritic cell therapy has been successfully used in the treatment of the following types of cancer:

• Malignant melanoma
• Renal cell carcinoma
• Colorectal cancer
• Cancer of the fallopian tubes
• Breast cancer
• Prostate gland cancer
• Sarcoma
• Lymphoma
• Defined leukaemia

The treatment with oncolytic (cancer dispersing) viruses

Even if it may seem so to some people, not all viruses are dangerous for humans, on the contrary: doctors and scientists now use certain viruses as cooperative partners in cancer therapy. These are the so-called oncolytic viruses, which are able to attack and destroy tumour cells. For this purpose the tumour cells are infected with an oncolytic virus, which multiplies in the tumour tissue. After destroying the first tumour cells, the virus is freed and attacks further tumour cells.

Newcastle Disease Virus (NDV) and dendritic cells

A promising candidate among the oncolytic viruses is the Newcastle Disease Virus (NDV). It is dangerous to fowl, but has absolutely no negative effects on human health. In human tumours, however, it multiplies very efficiently and can lead to an almost total cell lyses (destruction of cells) in the tumour within a short period of time.
In connection with dendritic cells there is a promising approach that consists of the dendritic cells being ‘pre-treated’ with tumour cells infected with NDV, in order to induce an increase of activity in the dendritic cells.
In this process, the dendritic cells make the immune system aware of the virus, upon which certain cytotoxic cells are activated. This means that whenever a tumour cell has been infected with the Newcastle Disease Virus it will be recognised as a foreign substance in the body and completely destroyed. Again, only very minor side effects or none at all have been observed in connection with this treatment.