Human immunodeficiency virus type 1 (HIV-1) infection confers an increased risk for the development of many cancers. Although the incidences of acquired immunodeficiency syndrome (AIDS)-defining malignancies have declined since the advent of antiretroviral therapy (ART), a number of non-AIDS–defining cancers appear more common in HIV-1–infected individuals relative to the general population. ART-treated HIV-1–infected subjects are also aging, leading to an increased cancer burden in these populations. However, longevity alone is not sufficient to explain these epidemiologic trends. A causative link between HIV-1–induced immune suppression and elevated cancer risk is well defined in certain malignancies; however, the direct role of HIV-1 replication products in oncogenesis remains unclear. Nevertheless, it is evident that cooperation between HIV-1 and co-infecting viruses in targeting immune compartments as well as nonimmune microenvironments can regulate both the development and progression of cancer. Treating cancer in HIV-1–infected patients remains challenging due to drug interactions, compounded side effects and intensified immunosuppression from chemotherapy and/or radiation. While survival of HIV-1–infected patients with certain cancers now rivals that of their uninfected counterparts, a better understanding of HIV-1–induced oncogenesis, viral mechanisms of immune perturbation, nonimmune microenvironmental abnormalities and outcomes of therapy will provide the basis for better diagnosis and management of cancer.
Part of the book: HIV/AIDS
Human immunodeficiency virus type 1 (HIV-1), the etiologic agent of acquired immunodeficiency syndrome (AIDS), primarily infects T cells and cells of the monocyte-macrophage lineage. This is due to the presence of the cell surface receptor CD4 and the coreceptors, CXCR4, and CCR5. While the T-cell has classically been the cell type associated with HIV-1 disease progression, cells of the monocyte-macrophage lineage have also been shown to play a major role in this viral pathologic process. Classically, this has involved monocytic cells in the peripheral blood and tissue macrophages, however, over the course of HIV disease, the promyelomonocytic cells of the bone marrow (BM) have also been shown to play a role in pathogenesis retroviral disease in that they play an integral role in the reseeding of the periphery and end-organ tissues. This has involved an initial infection of the bone marrow hematopoietic progenitor cells. Given this observation, over the years there have been a number of cell lines that have been developed and provided valuable insights into research questions surrounding HIV-1 infection of the monocyte-macrophage cell lineage. In this regard, we will examine the biological and immunological properties of these BM-derived cell lines with respect to their utility in exploring the pathogenesis of HIV-1 in humans.
Part of the book: Biology of Myelomonocytic Cells