Changes of blood T cell subsets following radiation therapy for breast cancer

Peripheral blood mononuclear cells exhibit increased mitochondrial respiration after adjuvant chemo- and radiotherapy for early breast cancer

BACKGROUND

Adjuvant chemo- and radiotherapy cause cellular damage to tumorous and healthy dividing cells. Chemotherapy has been shown to cause mitochondrial respiratory dysfunction in non-tumorous tissues, but the effects on human peripheral blood mononuclear cells (PBMCs) remain unknown.

AIM

We aimed to investigate mitochondrial respiration of PBMCs before and after adjuvant chemo- and radiotherapy in postmenopausal patients with early breast cancer (EBC) and relate these to metabolic parameters of the patients.

METHODS

Twenty-three postmenopausal women diagnosed with EBC were examined before and shortly after chemotherapy with (n = 18) or without (n = 5) radiotherapy. Respiration (O2 flux per million PBMCs) was assessed by high-resolution respirometry of intact and permeabilized PBMCs. Clinical metabolic characteristics and mitochondrial DNA (mtDNA) content of PBMCs (mtDN relative to nuclear DNA) were furthermore assessed.

RESULTS

Respiration of intact and permeabilized PBMCs from EBC patients significantly increased with adjuvant chemo- and radiotherapy (p = 6 × 10-5 and p = 1 × 10-7 , respectively). The oxygen flux attributed to specific mitochondrial complexes and respiratory states increased by 17-43% compared to before therapy initiation. Similarly, PBMC mtDNA content increased by 40% (p = 0.002). Leukocytes (p = 0.0001), hemoglobin (p = 0.0003), and HDL cholesterol (p = 0.003) concentrations decreased whereas triglyceride (p = 0.01) and LDL (p = 0.02) concentrations increased after treatment suggesting a worsened metabolic state. None of the metabolic parameters or the mtDNA content of PBMCs correlated significantly with PBMC respiration.

CONCLUSION

This study shows that mitochondrial respiration and mtDNA content in circulating PBMCs increase after adjuvant chemo- and radiotherapy in postmenopausal patients with EBC. Besides the increased mtDNA content, a shift in PBMC subpopulation proportions towards cells relying on oxidative phosphorylation, who may be less sensitive to chemotherapy, might influence the increased mitochondrial respiration observed iafter chemotherapy.

Whole Blood Transcriptional Fingerprints of High-Grade Glioma and Longitudinal Tumor Evolution under Carbon Ion Radiotherapy

Simple Summary

Particle therapy with carbon ions is a promising novel option for the treatment of recurrent high-grade glioma (rHGG). Lack of initial and sequential biopsies limits the investigation of rHGG evolution under therapy. We hypothesized that peripheral blood transcriptome derived from liquid biopsies (lbx) as a minimal invasive method may provide a useful decision support for identification of glioma grade and provide novel means for longitudinal molecular monitoring of tumor evolution under carbon ion irradiation (CIR). We demonstrate feasibility and report patient, tumor and treatment fingerprints in whole blood transcriptomes of rHGG patients with pre-CIR and three post-CIR time points.

Abstract

Purpose: To assess the value of whole blood transcriptome data from liquid biopsy (lbx) in recurrent high-grade glioma (rHGG) patients for longitudinal molecular monitoring of tumor evolution under carbon ion irradiation (CIR). Methods: Whole blood transcriptome (WBT) analysis (Illumina HumanHT-12 Expression BeadChips) was performed in 14 patients with rHGG pre re-irradiation (reRT) with CIR and 3, 6 and 9 weeks post-CIR (reRT grade III:5, 36%, IV:9, 64%). Patients were irradiated with 30, 33, 36 GyRBE (n = 5, 6, 3) in 3GyRBE per fraction. Results: WTB analysis showed stable correlation with treatment characteristics and patients tumor grade, indicating a preserved tumor origin specific as well as dynamic transcriptional fingerprints of peripheral blood cells. Initial histopathologic tumor grade was indirectly associated with TMEM173 (STING), DNA-repair (ATM, POLD4) and hypoxia related genes. DNA-repair, chromatin remodeling (LIG1, SMARCD1) and immune response (FLT3LG) pathways were affected post-CIR. Longitudinal WTB fingerprints identified two distinct trajectories of rHGG evolution, characterized by differential and prognostic CRISPLD2 expression pre-CIR. Conclusions: Lbx based WTB analysis holds the potential for molecular stratification of rHGG patients and therapy monitoring. We demonstrate the feasibility of the peripheral blood transcriptome as a sentinel organ for identification of patient, tumor characteristics and CIR specific fingerprints in rHGG.

Changes of gamma/delta T cells in blood after radiation therapy for prostatic cancer

The changes of the size of gamma/delta T (gamma delta T) and alpha/beta T (alpha beta T) cell subsets in the blood were examined after radiation therapy (66 Gy) for prostatic carcinoma in 17 men. Following radiation both subpopulations of T cells were reduced to 52% and 36% of starting values, respectively. gamma delta T cells were not replaced four months after radiation therapy, in contrast to alpha beta T cells, which were increased to 47% of initial values. The T alpha beta/T gamma delta ratio was significantly reduced immediately after radiation therapy but was normalised after four months. Blood gamma delta T cells may be reduced for a long time after radiation therapy and this may be true also for gamma delta T cells in irradiated epithelial organs and tumours.

Reassessment of human peripheral T-lymphocyte lifespan deduced from cytogenetic and cytotoxic effects of radiation

Estimates of the mean lifetime of human peripheral blood T-lymphocytes (PBTL) have ranged from 1.5 to 10 year. To derive an improved estimate, kinetic and dose parameters of four deterministic, two-compartment models of loss and replacement of human peripheral blood lymphocytes (PBL) were fitted to a previously published extensive data set on loss of dicentrics plus rings (DR) in PBL sampled from X-ray-treated ankylosing spondylitis patients for > 20-year-post-treatment, involving a fixed external-dose regimen (with dose to PBL unknown). The four models investigated all incorporated fixed dose-response submodels for radiation-induced cytogenetic damage and cell killing that were based entirely on in vitro data for X-ray-exposed human PBTL. Two of the models are shown to provide a reasonably good prediction not only of the data on DR loss to which the models were fit, but also of corresponding data on recovery of the mean of measured total PBL. The modelling results indicate that it is unlikely that long-lived human recirculating 'memory' PBTL are homogeneous with respect to lifespan, but rather that two major subpopulations, T1 and T2, are involved having mean lifespans (and approximately 95% confidence limits) estimated to be approximately 1.1 (0.76-1.9) and approximately 6.3 (5.8-6.9) year, respectively. One of the two models consistent with the data posits that T1 (possibly 'short-term antigen-memory') cells are approximately 60% of recirculating T-lymphocytes that convert at a rate of approximately 9% year-1 into T2 (possibly 'long-term antigen-memory') cells, and that the T1 cells are virtually all derived from a central-body source such as thymus and/or central lymphatic tissues.

Changes of lymphocyte subsets after local irradiation for early stage breast cancer and seminoma testis: long-term increase of activated (HLA-DR+) T cells and decrease of "naive" (CD4-CD45R) T lymphocytes

Blood lymphocyte subsets of early breast cancer patients and of men with stage I seminoma of the testis were studied up to 6 years after radiotherapy. Similar results were obtained in the two patient groups. After a temporary decrease, the CD4-w29 or "memory" T cells recovered completely, while the CD4-45R or "naive" T cells remained decreased up to 6 years after irradiation. The number of CD8 T lymphocytes did not change during or after treatment. Because of the decrease of a subset of CD4 cells, and the unchanged values of CD8 cells, the CD4/CD8 ratio decreased significantly after irradiation, and remained lower than before treatment up to 5-6 years after radiotherapy. The number of both HLA-DR positive CD4 and HLA-DR positive CD8 T cells ("activated" T cells) increased significantly after irradiation. The natural killer (NK) cells were not affected by treatment. We propose that the recovery of the CD4 cells is limited to the CD4-w29 ("memory") population because of thymic dysfunction in older humans. The impact of the observed immune modulation on the low susceptibility for infections after local irradiation, and on putative antitumour immune responses is discussed.

Immunologic changes after loco-regional radiotherapy and fractionated total body irradiation (TBI) in mice

The immunologic effects of fractionated irradiation to both hind limbs and the tail of adult (2.5-3 months old) male Balb/c mice were investigated. A dose of 34 Gy given in 17 fractions of 2 Gy, 1 fraction per day, 5 days per week, was delivered with a 60Co source. A significant decrease of the total splenocyte count (29% of control value) and of the PHA(phytohemagglutinin)-induced proliferation of T cells (22% of control value) was found immediately after irradiation. Both parameters normalized within 30 days after irradiation. Immediately after irradiation, the MLC (mixed lymphocyte culture) was supranormal (126% of control value), dropped to 45% 1 week later, and normalized within 1 month after radiotherapy. The NK (natural killer) activity was significantly decreased only the first week after loco-regional irradiation, while the LAK (lymphokine activated killer) activity was not altered at all. The percentage of goat-anti-mouse+ cells (mainly B lymphocytes) was not changed immediately after loco-regional irradiation, but rose to supranormal values (175% of control level) 3 months after irradiation. A persistent decrease of the percentage and the absolute numbers of the Lyt2+ cells (= CD8+ cells, suppressor/cytotoxic phenotype) was observed up to 3 months after irradiation, while the percentage of L3T4+ cells (= CD4+ cells, helper phenotype) remained normal for the total follow-up. No differences in allogeneic skin graft survival could be demonstrated between irradiated and control animals. The observed immunological effects could not be explained by the scatter irradiation to the whole body as total body irradiation (TBI) administered in a dose and dose rate similar to the scatter dose did not result in persistent immunologic changes. No dose-rate effect could be demonstrated in a low dose fractionated total body irradiation schedule. A total body irradiation similar to the scatter dose in humans did not result in significant immunologic changes.

Changes of the blood lymphocyte subpopulations and their functions following 131I treatment for nodular goitre and 32P treatment for polycythemia vera

The blood lymphocyte population was examined in 34 patients who were treated with 131I for toxic or atoxic nodular goitre. One to three doses of 300-550 MBq of 131I were administered at 1-week intervals. Lymphocyte counts were found to be significantly reduced at both 1 and 6 weeks after treatment. This decrease was accompanied by a changed composition of the lymphocyte subpopulations. The frequency of lymphocytes expressing membrane receptors for C'3 (EAC-rosette forming cells) was significantly reduced at 1 and 6 weeks following 131I administration. At 6 weeks there was a small but statistically significant increase of the frequency of T cells as identified by Leu 1 monoclonal antibodies. This was essentially due to an increased proportion of helper/inducer T cells as identified by Leu 3 monoclonals. 131I treatment also decreased the capacity of lymphocytes to secrete immunoglobulins (Ig) when stimulated with pokeweed mitogen (PWM). The greatest effect was observed for IgM. Secretion of IgG and IgA were less reduced. Mitogenic stimulations of lymphocytes with phytohemagglutinin (PHA) and concanavalin A were not significantly changed. It is concluded that these findings, with the exception of mitogen reactivity, are largely similar to those occurring following external radiation therapy for cancer. It is suggested that blood lymphocytes passing through the continuously irradiated gland are damaged mainly by beta-rays. The effect of 32P treatment on the blood lymphocyte population was examined in 16 patients with polycythemia vera. Before treatment the lymphocyte counts were within the normal range but the expression of certain membrane structures, as identified by monoclonal antibodies against total T cells (Leu 1 and 4), helper/inducer (Leu 3) and suppressor/cytotoxic T cells (Leu 2), were slightly decreased. Moreover, mitogenic responses of the lymphocytes to PHA and PWM-induced Ig secretion were impaired. Following a single oral dose of 32P (150-305 MBq), which normalized the production of erythrocytes and/or platelets, the blood lymphocyte counts were reduced by approximately 40 per cent 12 weeks after treatment. Examination of subsets demonstrated that the proportion of B-cells, as identified by B1 monoclonal antibodies, was decreased by the highest relative extent. On the other hand, lymphocytes expressing the above-mentioned T cell markers were somewhat increased. 32P treatment markedly increased PHA reactivity but it further reduced PWM-induced Ig secretion. The latter observation was in agreement with the finding that serum concentrations of Ig were reduced after treatment.

Changes in helper and suppressor T lymphocytes following radiotherapy for breast cancer

Changes in total lymphocyte, T lymphocyte, T helper and T suppressor lymphocyte numbers were studied in 22 patients with breast cancer before and after radiotherapy. T lymphocyte subsets were measured using monoclonal antibodies and fluorescence microscopy. After treatment the total lymphocyte count fell significantly and was still reduced 9 months later, but the proportion of cells labelled as T lymphocytes was unchanged during this period. The helper-suppressor ratio, which was within the normal range before radiotherapy, was significantly reduced at 3 months and 9 months after. Following treatment both T helper and T suppressor cell numbers were significantly reduced. T helper cell numbers remained reduced throughout the study period but T suppressor cell numbers showed a recovery to normal values 9 months after radiotherapy.

Changes of the blood lymphocyte population following 131I treatment for nodular goiter

The blood lymphocyte population was examined in 34 patients who were treated with 131I for toxic or atoxic nodular goiter. The patients received one to three doses of 300-550 MBq of 131I administered at 1 week intervals. Lymphocyte counts were significantly reduced both 1 and 6 weeks after treatment. This reduction was accompanied by a changed composition of the lymphocyte population. The frequency of lymphocytes expressing membrane receptors for C'3 (EAC-rosette forming) was significantly reduced 1 and 6 weeks after 131I-administration. At 6 weeks there was a slight but statistically significant increase of the frequency of T-cells as identified by Leu 1 monoclonal antibodies. This was largely caused by an increased proportion of helper/induced T-cells as identified by Leu 3a monoclonals. 131I-treatment also reduced the capacity of lymphocytes to secrete immunoglobulins (Ig) upon PWM-stimulation. The most pronounced effect was observed for IgM. Secretion of IgG and IgA were less reduced. Mitogenic stimulations of lymphocytes with PHA and ConA were not significantly changed. We conclude that these changes observed, with the exception of mitogen reactivity, are essentially similar to those occurring after external radiation therapy for cancer. We speculate that blood lymphocytes passing through the continuously irradiated gland are damaged mainly by emitted beta-particles.

Correlation of Fc gamma receptors on peripheral blood mononuclear cells and survival in patients with metastatic breast cancer

Patients with carcinomas have elevated levels of Fc receptors for IgG (Fc gamma R) on their peripheral blood mononuclear cells (PBMC). The purpose of the present study was to determine whether there is a correlation between Fc gamma R levels on PBMC and survival in patients with metastatic breast cancer. Binding assays were performed on PBMC using 125I-labeled fibrinogen complexed with rabbit IgG (or as a control F(ab')2) anti-human fibrinogen. Twenty-two metastatic breast cancer patients had significantly (p less than 0.001) elevated Fc gamma R levels as compared to either 22 breast cancer patients receiving adjuvant chemotherapy following mastectomy without clinical evidence of tumor, or to 34 non-malignant controls. Significantly more metastatic patients with elevated Fc gamma R levels died at 6 months (p less than 0.001) as compared to those with low levels. A direct correlation between Fc gamma R levels and hazard probability was found (correlation coefficient = 0.3321, p less than 0.005). These results raise the possibility that Fc gamma R levels on PBMC from metastatic breast cancer patients may be clinically useful as a prognostic marker of disease activity.

Long term effects on the immune system following local radiation therapy for breast cancer. I. Cellular composition of the peripheral blood lymphocyte population

Local radiation therapy for breast cancer depletes the blood of various subsets of lymphocytes. Previous studies showed that the recovery is still incomplete at 30 months. To further elucidate the recovery we examined blood lymphocyte counts of 138 disease-free women and various lymphocyte subsets in 102 of these patients. These patients, 5-6 and 10-11 years earlier, had entered a clinical trial in which preoperative irradiation (45 Gy) was evaluated against postoperative irradiation (45 Gy) or surgery only. Patients who had undergone surgery only served as controls. Total lymphocyte counts of the irradiated patients were still significantly reduced 10-11 years after treatment. This reduction was mainly attributable to a subnormal level of T-cells as determined by the monoclonal antibody Leu-1 and the ability to form rosettes with sheep erythrocytes, whereas the number of non-T cells, expressing C'3 receptors, did not differ significantly from the controls. Within the T-cell population a subset with helper/inducer phenotypes, detected by Leu-3a antibodies, was significantly reduced even 10-11 years after irradiation. T-cells with suppressor/cytotoxic phenotypes, stainable with Leu-2a antibodies, however, had already recovered 5-6 years after irradiation. The duration of the radiation induced reductions of different lymphocyte subsets may be related to the physiological turn-over of the cells or a changed distribution of cells in the body.

Cells responsible for tumor surveillance in man: effects of radiotherapy, chemotherapy, and biologic response modifiers

Currently, the most probable theory of tumor surveillance is neither the existence of any tumor-specific, antigen-dependent, T-cell-mediated cytotoxic effect that could eliminate spontaneous tumors in man and that could be used for some kind of vaccination against tumors, nor the complete absence of any surveillance or defense systems against tumors. What is probable is the cooperation of a number of antigen-independent, relatively weakly cytotoxic or possibly only cytostatic humoral and cellular effects, including nutritional immunity, tumor necrosis factor, certain cytokines, and the cytotoxic effects mediated by macrophages, NK cells, NK-like cells, and certain stimulated T-cells. One question remaining to be solved is why these antigen-independent effects do not attack normal cells. A number of plausible hypotheses are discussed. The hypothetical surveillance system is modulated both by traditional cancer treatment and by attempts at immunomodulation. Radiotherapy reduced the T-helper cell function for almost a decade, but not those of macrophages or NK cells. T-cell changes have no prognostic implication, supporting, perhaps, the suggestion of a major role for macrophages and NK cells. Cyclic adjuvant chemotherapy reduces the peripheral lymphocyte population and several lymphocyte functions but not NK activity. Most of the parameters were normalized some years following treatment, but NK activity remained elevated and Th/Ts cell ratio was still decreased. This might possibly be taken to support the surveillance role of NK cells. Bestatin increases the frequency of lymphocytes forming rosettes with sheep red blood cells (but not their mitogenic responses), enhances NK activity, and augments the phagocytic capacity of granulocytes and monocytes (but not their cytotoxic activity). Improved survival with Bestatin treatment following chemotherapy has been observed in patients with melanoma Stages 1b and II and in patients with acute nonlymphatic leukemia, where BCG also seems active, although possibly only in patient groups with less than 49% complete remissions.

Changes of blood T cell subsets in patients receiving postoperative adjuvant chemotherapy for breast cancer

The number of T helper (Th) and T suppressor (Ts) cells, as defined by monoclonal antibodies, of the blood lymphocyte population was examined in breast cancer patients receiving postoperative cyclic therapy with cyclophosphamide, methotrexate and 5-fluorouracil. The total number of lymphocytes was reduced to approximately 50% at the end of the 17-month period of chemotherapy. Identification of Th and Ts subsets with the aid of Leu-3a and Leu-2a antibodies revealed that the former was reduced to a higher relative extent than the latter, thus reducing the Th/Ts ratio highly significantly during the entire treatment period. A reduced ratio was also observed in a group of patients having completed their treatment 2-3 yr earlier.