Chronic lymphocytic leukemia B cells inhibit spontaneous Ig production by autologous bone marrow cells: role of CD95-CD95L interaction

Secondary Immunodeficiency in Hematological Malignancies: Focus on Multiple Myeloma and Chronic Lymphocytic Leukemia

Secondary immunodeficiency is reported in most patients with hematological malignancies such as chronic lymphocytic leukemia and multiple myeloma. The aim of our review was to evaluate the existing literature data on patients with hematological malignancies, with regard to the effect of immunodeficiency on the outcome, the clinical and therapeutic approach, and on the onset of noninfectious complications, including thrombosis, pleural effusion, and orofacial complications. Immunodeficiency in these patients has an intense impact on their risk of infection, in turn increasing morbidity and mortality even years after treatment completion. However, these patients with increased risk of severe infectious diseases could be treated with adequate vaccination coverage, but the vaccines' administration can be associated with a decreased immune response and an augmented risk of adverse reactions. Probably, immunogenicity of the inactivated is analogous to that of healthy subjects at the moment of vaccination, but it undertakes a gradual weakening over time. However, the dispensation of live attenuated viral vaccines is controversial because of the risk of the activation of vaccine viruses. A particular immunization schedule should be employed according to the clinical and immunological condition of each of these patients to guarantee a constant immune response without any risks to the patients' health.

Immune Dysfunctions and Immune-Based Therapeutic Interventions in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by a wide range of tumor-induced alterations, which affect both the innate and adaptive arms of the immune response, and accumulate during disease progression. In recent years, the development of targeted therapies, such as the B-cell receptor signaling inhibitors and the Bcl-2 protein inhibitor venetoclax, has dramatically changed the treatment landscape of CLL. Despite their remarkable anti-tumor activity, targeted agents have some limitations, which include the development of drug resistance mechanisms and the inferior efficacy observed in high-risk patients. Therefore, additional treatments are necessary to obtain deeper responses and overcome drug resistance. Allogeneic hematopoietic stem cell transplantation (HSCT), which exploits immune-mediated graft-versus-leukemia effect to eradicate tumor cells, currently represents the only potentially curative therapeutic option for CLL patients. However, due to its potential toxicities, HSCT can be offered only to a restricted number of younger and fit patients. The growing understanding of the complex interplay between tumor cells and the immune system, which is responsible for immune escape mechanisms and tumor progression, has paved the way for the development of novel immune-based strategies. Despite promising preclinical observations, results from pilot clinical studies exploring the safety and efficacy of novel immune-based therapies have been sometimes suboptimal in terms of long-term tumor control. Therefore, further advances to improve their efficacy are needed. In this context, possible approaches include an earlier timing of immunotherapy within the treatment sequencing, as well as the possibility to improve the efficacy of immunotherapeutic agents by administering them in combination with other anti-tumor drugs. In this review, we will provide a comprehensive overview of main immune defects affecting patients with CLL, also describing the complex networks leading to immune evasion and tumor progression. From the therapeutic standpoint, we will go through the evolution of immune-based therapeutic approaches over time, including i) agents with broad immunomodulatory effects, such as immunomodulatory drugs, ii) currently approved and next-generation monoclonal antibodies, and iii) immunotherapeutic strategies aiming at activating or administering immune effector cells specifically targeting leukemic cells (e.g. bi-or tri-specific antibodies, tumor vaccines, chimeric antigen receptor T cells, and checkpoint inhibitors).

Progesterone-induced apoptosis in immortalized normal and malignant human ovarian surface epithelial cells involves enhanced expression of FasL

Progesterone (P4) has been implicated as a protective factor for epithelial ovarian cancers, yet little is known about its mechanism of action. We previously reported that pregnancy-equivalent doses of P4 inhibited the growth of normal and malignant human ovarian surface epithelial (HOSE) cells. Here, we investigated how P4-induced cell death in two immortalized normal (HOSE 642, HOSE 12-12) and two malignant (OVCA 429, OVCA 432) HOSE cell lines. The exposure of HOSE or OVCA cell cultures to 10(-6) M P4 induced time-dependent increases in early and late apoptotic cells and activation of caspase-8 and -3, but not that of caspase-9. A general caspase inhibitor Z-VAD effectively blocked the P4-induced cell death in a dose-dependent manner. Comparable levels of Fas mRNA and protein were expressed in HOSE and OVCA cell lines, and these levels were unaffected by P4. In contrast, levels of FasL mRNA and protein were higher in OVCA cells than in HOSE cells. Interestingly, the hormone enhanced levels of FasL mRNA and protein in HOSE cells, but lowered their levels in OVCA cells. The exposure of HOSE or OVCA cells to an activating anti-Fas antibody induced cell loss, whereas treatment of cells with a blocking anti-FasL antibody reduced the P4-induced cell loss. Cotreatment of cells with the activating anti-Fas antibody and P4 produced additive effects on cell loss. These results reveal for the first time that P4 induces apoptosis in HOSE and OVCA cells via activation of a caspase-8-initiated Fas/FasL signaling pathway. They also demonstrate differential P4-regulation of FasL expression between HOSE and OVCA cells.