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Cancer & AIDS – The Concept of Immunosurveillance

Cancer and Aids are still considered as the two major medical catastrophe where brilliant minds fail to unearth the cure. Several studies and researches have linked cancer and aids in the immune system—and the concept of immunosurveillance, which scientists believed that will unlock the extensive search for cure.

In the study of Vesely et al (2011), cancer immunosurveillance is defined as the process of the immune system to identify and destroy the emerging tumor cells—which plays a vital role in the defense against cancer. It was proven that innate and adaptive immune cell types with effector molecules can be an extrinsic tumor-suppressor. The mechanism called immunoediting is where the dual host-protective and the tumor-promoting actions of immunity functions together. However, the immune system can also promote tumor development.

In another study about the interactions of the immune system and malignant tumor has explained the mechanisms of tumor-mediated regulation of immunity. Block & Markovic (2009) demarcated that immune system works either to prevent or contain tumor growth. The study concluded that people with immune deficiency are high risk for the development of cancer since cellular aberrations are more aggressive in the tumor-targeted inflammation. Cancer cells commonly produce cell surface molecules called cytokines and growth factors that disrupt normal immunity to support their progression.

The destructive cycles that are started within cells, due to failure to appropriately engage and/or disengage either arm of the immune system, can result in the following: excessive tissue remodeling, loss of tissue architecture due to tissue destruction, and alterations in protein and DNA caused by oxidative stress that increases the risk of cancer development (De Visser et al., 2006).

In the study of Carbone (2003), it was found that the diffuse proliferation of neoplastic cells contains a scant cytoplasm and round uniform nuclei with two to five small but distinct nucleoli—a starry-sky pattern due to the presence of many stainable macrophages containing abundant clear cytoplasm (generally macrophages contain cellular debris from necrotic neoplastic cells).

Moreover, if cancer cells promote abnormal cellular growth for its progression by affecting the normal immunity mechanism, AIDS causes apoptosis that totally disrupts immunesurveillance system.

Apoptosis, or the programmed death of a cell, is very important in regulating the number of cells in an organ or tissue. In the presence of AIDS, the apoptotic process is completely disrupted wherein death cell caused by an imposed injury due to a virus causing destruction of the plasma membrane. When the cell swells, it releases cytoplasmic materials inducing an inflammatory response. The case is worsened by the immunosuppressant AIDS virus that disrupts the phagocytic action of apoptosis (Vander et al., 2001).

HIV infection is related to a reduction of cell-mediated immunity, and the failure of CD4-helper T cells to recognize clones of abnormal proliferating cells may be one of the reasons behind the development of AIDS-associated malignancies. The humoral predominant chronic immune activation seen in AIDS may also be vital in providing the environment necessary for oncogenic viruses to induce Kaposi’s Sarcoma, lymphoma, and anogenital cancers. Loss of tumor suppressor genes—referred to as the loss of the heterozygosity pathway—and genetic instability at the microsatellite loci are among these genetic alterations, both involved in tumor progression in AIDS-related malignancies (Bellan et al., 2003).

The relations between immune cells to cancer and AIDS have been known for a century. Cancer and AIDS are still incurable—but why do we need to search for cure if this medical catastrophe is preventable? Prevention is better than Cure! Immunosurveillance will never be disrupted without carcinogens (cancer) and virus (AIDS). Cancer and AIDS can be avoided with healthy lifestyle—maybe that’s the cure that people only ignore.

References


  1. Bellan, C., De Falco, G. & Leoncini, L. (2003). Pathologic Aspects of AIDS Malignancies. Oncogene, 22, 6639–6645. Block, M.S. & Markovic, S.N. (2009). The Tumor / Immune Interface: Clinical Evidence of Cancer Immuosurveillance, Immunoediting and Immunosubversion.
  2. American Journal of Immunology, 5(1), 29–49. Carbone, A. (2003). Emerging Pathways in the Development of AIDS-related Lymphomas. The Lancet Oncology, 4(1), 22–29.
  3. De Visser, K.E., Eichten, A. & Coussens, L.M. (2006). Parodoxical Roles of the Immune System During Cancer Development. Nature Reviews Cancer, 6, 24–35. Vander, A.J., Sherman, J.H. & Luciano, D.S. (2001). Human Physiology: The Mechanism of Body Function, 8th ed., New York: McGraw-Hill, 154–155.
  4. Vesely, M.D. et al. (2011). Natural Innate and Adaptive Immunity to Cancer. Annual Review of Immunology, 29, 235–271. 

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