Biology of chronic lymphocytic leukemia.
B-cell chronic lymphocytic leukemia (CLL) lies at the cross-roads of hematology, immunology and oncology for at least three major reasons: (a) it is the prototype of human malignancies that primarily involve defects in the induction of apoptosis; (b) CLL patients develop a severe immunodeficiency with progressive hypogammaglobulinemia; and (c) they have a high prevalence of autoimmune phenomena. Recent advances in the biology of the malignant cell in CLL lead to a scenario comprised of two basic elements: first, CLL cells are optimally organized to survive in their niches because their ability to undergo apoptosis is severely hampered; second, they have a microenvironment-dependence that promotes their extended survival, a situation that arises most probably through direct cell-to-cell contacts. In addition, CLL cells themselves are the major accessory cells in CLL, but are inefficient antigen-presenting cells. This latter defect may provide a clue to reinterpret the events of immunodeficiency and autoimmunity.
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Divisione Universitaria di Immunologia Clinica, Ospedale Mauriziano Umberto I, Dipartimento di Scienze Biomediche e Oncologia Umana, Università di Torino, Torino, Italy.
D000938:Antigen-Presenting Cells / Q000473:pathology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000276:immunology / Q000473:pathology; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000209:etiology* / Q000276:immunology / Q000473:pathology