In memory of Jill and Sakura

What is Immunotherapy (NK Cells) for Dogs?

The immune system is classically divided into innate and adaptive. Adaptive immunity can be defined by the presence of cells (i.e. T and B lymphocytes in higher vertebrates) that clonally express a colossal repertoire of receptors (i.e. the T cell and the B cell antigen receptors), the diversity of which results from somatic DNA rearrangements.

Besides T and B cells, NK cells are lymphocytes of the innate immune system that can kill an array of target cells and secrete cytokines that participate to the shaping of the adaptive immune response and to tissue repair.

A feature of NK cells resides in their capacity to distinguish stressed cells (such as tumor cells, microbe-infected cells, cells which have undergone physical or chemical injuries) from normal cells.

Immunotherapy, also called biologic therapy, is a type of cancer treatment designed to boost the body’s natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to improve, target, or restore immune system function. It is not entirely clear how immunotherapy treats cancer. However, it may work in the following ways:

  • Stopping or slowing the growth of cancer cells
  • Stopping cancer from spreading to other parts of the body
  • Helping the immune system work better at destroying cancer cells

There are several types of immunotherapy, including:

  • Monoclonal antibodies
  • Non-specific immunotherapies
  • Cancer vaccines
  • Oncolytic virus therapy

Natural Killer cells and Innate Immunity


Bonkobara M, Saito T, Yamashita M, Tamura K, Yagihara H, Isotani M, Sato T, Washizu T. Blastic natural killer cell leukaemia in a dog–a case report. Vet. J. 2007;174:659–662.


Boysen P, Storset AK. Bovine natural killer cells. Vet. Immunol. Immunopathol. 2009;130:163–177.


Colleen M. O’Connor, PhD, is a research investigator in the Division of Pediatrics at the University of Texas MD Anderson Cancer Center in Houston, Texas.

Heather Wilson-Robles is an assistant professor in the Department of Small Animal Clinical Sciences at the Texas A&M University College of Veterinary Medicine in College Station, TX.

Eric Vivier, DVM, PhD, PU-PHCE
Member of the National Academy of Medicine
Member of the Institut Universitaire de France
Member of the experts panel for the European Research Council Starting Grant
Masters of Immunology, Cancer Immunology essentials

Ali A. Ashkar, DVM, PhD
McMaster Immunology Research Centre and Institute for Infectious Diseases Research, Department of Pathology and Molecular Medicine
McMaster University Health Sciences Center Hamilton, Ontario, Canada


White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell. Leukocytes are found throughout the body, including the blood and lymphatic system. There are five major types of white blood cells:
  • Neutrophils, Lymphocytes, Eosinophils, Monocytes and Basophils
  • B cells: releases antibodies and assists activation of T cells
  • T cells:
    • CD4+ Th (T helper) cells: activate and regulate T and B cells
    • CD8+ cytotoxic T cells: virus-infected and tumor cells.
    • γδ T cells: bridge between innate and adaptive immune responses; phagocytosis
    • Regulatory (suppressor) T cells: Returns the functioning of the immune system to normal operation after infection; prevents autoimmunity
  • Natural killer cells: virus-infected and tumor cells


Immunotherapy is treatment that uses certain parts of a person’s immune system to fight diseases such as cancer. This can be done in a couple of ways:

  • Stimulating your own immune system to work harder or smarter to attack cancer cells
  • Giving you immune system components, such as man-made immune system proteins

Some types of immunotherapy are also sometimes called biologic therapy or biotherapy.

In the last few decades immunotherapy has become an important part of treating some types of cancer. Newer types of immune treatments are now being studied, and they’ll impact how we treat cancer in the future.

Immunotherapy includes treatments that work in different ways. Some boost the body’s immune system in a very general way. Others help train the immune system to attack cancer cells specifically. Immunotherapy works better for some types of cancer than for others. It’s used by itself for some of these cancers, but for others it seems to work better when used with other types of treatment.

Natural killer (NK) cells are lymphocytes that were first identified for their ability to kill tumor cells without deliberate immunization or activation. Subsequently, they were also found to be able to kill cells that are infected with certain viruses and to attack preferentially cells that lack expression of major histocompatibility complex (MHC) class I antigens. The recent discovery of novel NK receptors and their ligands has uncovered the molecular mechanisms that regulate NK activation and function.

Several activating NK cell receptors and costimulatory molecules have been identified that permit these cells to recognize tumors and virus-infected cells. These are modulated by inhibitory receptors that sense the levels of MHC class I on prospective target cells to prevent unwanted destruction of healthy tissues. In vitro and in vivo, their cytotoxic ability can be enhanced by cytokines, such as interleukin (IL)-2, IL-12, IL-15 and interferon alpha/beta (IFN-alpha/beta). In animal studies, they have been shown to play a critical role in the control of tumor growth and metastasis and to provide innate immunity against infection with certain viruses.

Following activation, NK cells release cytokines and chemokines that induce inflammatory responses; modulate monocyte, dendritic cells, and granulocyte growth and differentiation; and influence subsequent adaptive immune responses. The underlining mechanism of discriminating tumor cells and normal cells by NK cells has provided new insights into tumor immunosurveillance and has suggested new strategies for the treatment of human cancer.


Most Veterinarians in Singapore are trained in conventional medicine using a combination of radiation, chemo drugs or surgery to manage canine cancer. There are a handful of Veterinarians that will recommend supplements, nutraceutical and Traditional Chinese Medicine. Radiation treatment in Singapore is not available at all. So your pet only has two choices, surgery and chemo drugs. And if the cancer is growing at some places that surgery is not possible, than chemotherapy would be recommended by most Veterinarians.

But this is not entirely true at all. Some therapies such as Ozone Therapy, Hyperbaric Therapy and Immunotherapy are available. Such therapies are not recommended by Veterinarians as it is classified as non-conventional approaches. But there are alot of researches done for human using such therapies, especially Immunotherapy.

However, come cancer growing in your pets are aggressive in nature and they multiply pretty quickly. Adopting the quickest method is crucial.

NK Cell Therapy requires the vet to extract cells (blood) from your pet and it takes three weeks to cultivate them. Upon cultivation, they will be reintroduce to your pet under the supervision of a Veterinarian. Rejection of the NK cells is kept minimum as the cells are grown from the host itself. The cost of this treatment for now is SGD$ 1700.00 and it can be recommended over a 3 to 8 months period. During these three weeks, a very low dose of chemo drugs might be recommended, and it is important to provide a list of supplements for your dogs during this three crucial week.

If you are keen in engaging this therapy for your dog, please contact Dr Jean Paul Ly. At the point of publishing this article, he is the only veterinarian that performs this treatment.