The data suggest that concentrations of antimicrobial peptides are correlated with severity of CF lung disease: Levels of LL-37/hCAP-18 are associated with bronchial inflammation and, therefore disease severity, whereas decreased levels of beta-defensins in advanced lung disease likely contribute to a secondary defect of the local host defense.
In CML patients, lymphocyte subsets have been shown to be disturbed. NK cells as well as CD8+ T cells have been shown to be significantly lower in patients with relapse after BMT than without relapse (Jiang et al., 1996). After successful treatment (IFN- α and BMT/SCT), MHC-restricted CD8+ T cells as well as MHC-unrestricted cytotoxic NK and lymphokine activated killer (LAK) cells play an important role in controlling the disease (Meseri et al., 1993, de Castro et al., 2003, Molldrem et al., 2000), which can lead not only to hematological, but also cytogenetic responses. The development of imatinib mesylate, a selective inhibitor of the bcr/abl tyrosine kinase, as a first-line therapy enormously enhanced treatment options for CML patients, and has led to hematologic, and occasionally cytogenetic, responses at various stages of disease. To explore, if CML patients, who develop clinical responses with imatinib mesylate treatment, have normalization of their lymphocyte subsets with restoration of CD8+ and NK cells, we studied peripheral blood T cell, B cell, and NK cell subpopulations in patients in chronic or accelerated phase before and after treatment with imatinib mesylate. In 5 CML patients, 8-color flow cytometry was applied to investigate the lymphocyte subsets using anti-CD3, anti-CD4, anti-CD8, anti-CD19, anti-CD56, anti-CD25, anti-CD27, and anti-CD45RA antibodies. 5 healthy donors served as controls. There was no significant difference in CD19+ B cells or CD3+ T cells as well as its CD4+ and CD8+ subsets between CML patients and healthy controls. T regulatory cells (CD4+CD25+) were also similar in patients in comparison to the healthy controls (0.6% – 3% vs 2.3%). In contrast, CD3–CD56+ NK cells (4% vs 14%, p<0.05) as well as NK T cells (CD3+CD56+ 1% vs 14%, p<0.02; CD8+CD56+ 2% vs 17%, p<0.03) were profoundly decreased in CML patients compared to the healthy controls prior to treatment with imatinib mesylate. Importantly, these abnormalities persisted even during treatment and following hematological responses (range 10 months – 35 months) (CD3-CD56+ 4–8%, CD3+CD56+ 0.5–5.5%, CD8+CD56+ 2.7–7%). On further analysis, these NK and NKT cells were mostly effector (CD45RA+CD27−, 50–80%) or memory (CD45RA-CD27+, 10–30%) cells. These results suggest, that CML not only disturbs the myeloid and the lymphoid compartment before treatment, but persistently impairs the MHC-unrestricted cytotoxic NK cells and NKT cells after treatment with imatinib mesylate, even in patients in hematological (and cytogenetic) remission with normal white cell counts (2.0 – 8.0/nl). Further investigations are required to better understand the mechanism of the prolonged and specific NK and NKT cell suppression in imatinib mesylate treated patients, and its impact on the course of the disease.
Imatinib mesylate, a selective inhibitor of the bcr/abl tyrosine kinase, has revolutionized the treatment of patients with chronic myelogenous leukemia (CML). Most CML patients in chronic phase achieve hematologic remission with imatinib, while some achieve cytogenetic remission. As imatinib is an oral agent with few side effects, it has rapidly become the first-line therapy for most CML patients. However, this therapy does not represent a cure, as patients who discontinue the drug invariably relapse. Furthermore, imatinib resistance is beginning to emerge in some patients. Hence, the need to find alternate, potentially curative, therapies for CML remains. To date, the only curative treatment for CML is allogeneic bone marrow or stem cell transplantation (ABMT). A major mechanism of the curative potential of ABMT is immunological, as evidenced by the poor clinical outcome with T cell-depleted ABMT, and the efficacy of donor lymphocyte infusions (DLI) upon relapse. We hypothesized that an effective anti-leukemia immune response may emerge in patients entering remission on imatinib which may contribute to its clinical effectiveness. If so, strategies to further enhance this anti-leukemia immune response may lead to a potential cure. To determine if CML patients in remission on imatinib develop anti-leukemia immune responses, blood and bone marrow samples from patients before and after treatment were collected and analyzed. Pre-treatment samples were utilized as sources of autologous leukemic cells to detect anti-leukemia immune responses in post-treatment samples in IFN-g ELISPOT assays. Pre-treatment samples alone, post-treatment samples alone, and when available, serial post-treatment samples mixed together served as controls. In 9 of 14 patients investigated, IFN-g release was detected in pre- and post-treatment samples together with a median response of 22 spots above background (range 10 – 56 dots, p<0.01), whereas serial post-treatment samples together in 8 patients yielded results similar to background (median 5, range 5 – 20). In 6 of these patients in hematologic (or cytogenetic) remission, sufficient cells were available to allow additional analyses via intracellular staining for IFN-g, TNF-a, and IL-2 in autologous leukemia stimulated T cells (CD4 and CD8) and NK cells. In 4 of 6 patients, leukemia-reactive T cells were detected, most prominently in CD4+ T cells expressing TNF-a (1.4 – 37%), followed by IL-2 (0.3 – 12%) and IFN-g (0.1 – 4.6%). NK cells did not show significant expression of these cytokines upon stimulation with autologous leukemia cells. In pre-treatment and post-treatment samples alone, IL-2, TNF-a, and IFN-g expression was not detectable (0 – 0.5%). These results suggest that a significant portion of CML patients in remission with imatinib develop an anti-leukemia immune response, most notably in CD4+ T cells. Mechanisms by which imatinib treatment leads to anti-leukemia immune responses, and the molecular targets to which these cells are directed, will be further investigated. This knowledge will be useful in the development of immunotherapy strategies against CML as well as other leukemias, and raises the hope that immunotherapy may be combined with imatinib to eradicate residual leukemia cells for a durable cure of the disease. intracellular cytokine staining CD4+ T Cells CD8+ T Cells IL-2 IFN- γ TNF- α IL-2 IFN- γ TNF- α pt 1 0.3 0 0.8 0.1 0.1 0.5 pt 1 0.3 0.1 1.4 0.1 0.1 0.4 pt 2 2.6 0.8 10.3 2.2 2.1 6.1 pt 3 21 2 37 2.3 0.7 1.7 pt 4 12 4.6 19 6.3 1.8 5.8
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.