Evaluating Anti-tumor Immune Responses of Protein Nanoparticle-Based Cancer Vaccines.

Cancer vaccines displaying tumor-associated antigens (TAAs) train the immune system for enhanced tumor recognition and elimination. Nanoparticle-based cancer vaccines are ingested and processed by dendritic cells, which subsequently activate antigen-specific cytotoxic T cells, allowing them to identify and eliminate tumor cells displaying these TAAs. Here, we describe the procedures to conjugate TAA and adjuvant to a model protein nanoparticle platform (E2), followed by assessment of vaccine performance. Utilizing a syngeneic tumor model, the efficacy of in vivo immunization was determined by cytotoxic T lymphocyte assays and IFN-γ ELISpot ex vivo assays to measure tumor cell lysis and TAA-specific activation, respectively. In vivo tumor challenge directly allows evaluation of anti-tumor response and survival over time.

Macromolecular assembly of bioluminescent protein nanoparticles for enhanced imaging.

Bioluminescence imaging has advantages over fluorescence imaging, such as minimal photobleaching and autofluorescence, and greater signal-to-noise ratios in many complex environments. Although significant achievements have been made in luciferase engineering for generating bright and stable reporters, the full capability of luciferases for nanoparticle tracking has not been comprehensively examined. In biocatalysis, enhanced enzyme performance after immobilization on nanoparticles has been reported. Thus, we hypothesized that by assembling luciferases onto a nanoparticle, the resulting complex could lead to substantially improved imaging properties. Using a modular bioconjugation strategy, we attached NanoLuc (NLuc) or Akaluc bioluminescent proteins to a protein nanoparticle platform (E2), yielding nanoparticles NLuc-E2 and Akaluc-E2, both with diameters of ∼45 â€‹nm. Although no significant differences were observed between different conditions involving Akaluc and Akaluc-E2, free NLuc at pH 5.0 showed significantly lower emission values than free NLuc at pH 7.4. Interestingly, NLuc immobilization on E2 nanoparticles (NLuc-E2) emitted increased luminescence at pH 7.4, and at pH 5.0 showed over two orders of magnitude (>200-fold) higher luminescence (than free NLuc), expanding the potential for imaging detection using the nanoparticle even upon endocytic uptake. After uptake by macrophages, the resulting luminescence with NLuc-E2 nanoparticles was up to 7-fold higher than with free NLuc at 48 â€‹h. Cells incubated with NLuc-E2 could also be imaged using live bioluminescence microscopy. Finally, biodistribution of nanoparticles into lymph nodes was detected through imaging using NLuc-E2, but not with conventionally-labeled fluorescent E2. Our data demonstrate that NLuc-bound nanoparticles have advantageous properties that can be utilized in applications ranging from single-cell imaging to in vivo biodistribution.

Immunological and psychosocial functioning in parents of children with cancer.

PURPOSE: Research has shown that parents of children with cancer exhibit an altered immune profile compared to parents of healthy children, reflective of increased susceptibility to illness. These parents are also at risk for poorer psychosocial outcomes and quality of life. The current study compares peripheral blood cell analyses and psychosocial self-reports from parents of children being treated for cancer (n = 21) to parents of healthy children (n = 30). METHODS: A blood sample was drawn from parents to analyze immune profiles. Parents also completed the Perceived Stress Scale (PSS), Medical Outcomes Study Short Form-36 (MOS), and Patient-Reported Outcomes Measurement Information System Short Form v1.0 Emotional Distress-Anxiety 8a, and Emotional Distress-Depression 8a (PROMIS). Mann-Whitney U tests and independent samples t-tests were conducted to examine differences in outcomes between parent groups. RESULTS: Parents of children with cancer exhibited higher monocyte percentages in their peripheral blood compared to peers with healthy children. Parents of children with cancer also reported poorer psychosocial outcomes: higher perceived stress, higher anxiety and depression symptoms, more role disability resulting from emotional problems, poorer general and mental health, and poorer social functioning. CONCLUSION: These findings support research that has shown a direct effect of chronic stress on the immune system. Symptoms reported by parents of children with cancer indicate unmet psychosocial needs that could potentially affect long-term health. Given the central role of parents in their children's cancer care, it is compelling to address and work to improve parent immunological and psychosocial well-being.

Longitudinal Changes in Sleep: Associations with Shifts in Circulating Cytokines and Emotional Distress in a Cancer Survivor Population.

BACKGROUND: Sleep disturbances are associated with numerous mood disorders. Similarly, anxiety and depression are associated with modulation of the psychoneuroimmune (PNI) axis. This study hypothesized that changes in both monitored and self-reported measures of sleep would relate to changes in circulating cytokine levels in an emotionally distressed population of cervical cancer survivors. METHODS: Biospecimens, patient-reported outcome (PRO) measures, and actigraphy were collected from cervical cancer survivors enrolled in a biobehavioral clinical trial. Longitudinal changes over a 4-month period were examined. Sleep time measured by actigraphy and PRO were analyzed for correlative changes with emotional distress and serum cytokines (n = 71). RESULTS: Longitudinal change in the actigraph measure of sleep time was inversely associated with changes in depression and anxiety (test for linear trend, p = 0.02 and p = 0.05 respectively), as well as acute-phase response/pro-inflammatory cytokines (test for linear trend, p = 0.003, interleukin (IL)-2; 0.022, IL-1ß; 0.0002, IL-6; and 0.049, tumor necrosis factor α). Conversely, changes in self-reported sleep problems were related to an increase in depression and anxiety (p = 0.001 and p = 0.01 respectively), the T helper 2 (Th2) cytokine IL-5 (p = 0.027), and the counter-regulatory cytokine IL-10 (0.016). CONCLUSION: This study showed that an increase in sleep time or decrease in sleep problems corresponded with a reduction in self-reported emotional distress and attenuation of pro-inflammatory, Th2, and counter-regulatory cytokines. Our results support sleep measurement as a meaningful biobehavioral variable in cancer survivorship. This study also indicates that sleep investigators should be aware that choice of methodology might influence concordance with different classes of immune parameters.

Relationship between social support, quality of life, and Th2 cytokines in a biobehavioral cancer survivorship trial.

OBJECTIVE: Benefits of social support (SS) during cancer survivorship are complex. This study examines change in SS over time in cervical cancer (CXCA) survivors who have completed definitive treatment and how changing SS impacts quality of life (QOL) and T-helper type 2 (Th2) cytokines. METHODS: We conducted a randomized trial in 204 CXCA survivors to test if psychosocial telephone counseling (PTC) could improve QOL compared to usual care (UC). Although PTC did not target SS, data were collected at baseline, 4 and 9 months post-enrollment using the Medical Outcomes Survey Social Support scale. Biospecimens were collected to investigate associations with patient-reported outcomes. Data were analyzed using multivariate linear models and stepwise regression. RESULTS: Participants' mean age was 43. PTC participants experienced increasing SS compared to UC at 4 months (PTC-UC = 5.1; p = 0.055) and 9 months (PTC-UC = 6.0; p = 0.046). Higher baseline SS and increasing SS were independently associated with improved QOL at 4 and 9 months after adjusting for patient characteristics (p < 0.05). Differences between study arms were not statistically significant. Improvements in QOL at 4 months were observed with increases in emotional/informational and tangible SS. Increasing SS predicted significant longitudinal decreases in IL-4 and IL-13 at 4 months that were larger in the PTC arm (interactions p = 0.041 and p = 0.057, respectively). CONCLUSION: Improved SS was significantly associated with improved QOL independent of patient characteristics and study arm. Decreasing Th2 cytokines with increasing SS and QOL are consistent with a biobehavioral paradigm in which modulation of the chronic stress response is associated with shifts in immune stance.

Health Behaviors in Cervical Cancer Survivors and Associations with Quality of Life.

PURPOSE: Improvement in health behaviors following cancer diagnosis may contribute to better prognosis and well-being. This study examines the prevalence of health behaviors in cervical cancer survivors who have completed treatment, and associations between health behaviors and quality of life (QOL). METHODS: We recruited 204 women who had completed treatment for cervical cancer to participate in a randomized counseling intervention. Participants provided information on health behaviors (smoking, physical activity, and alcohol consumption); QOL (Functional Assessment of Cancer Therapy-Cervical questionnaire); and depression (Patient-Reported Outcomes Measurement Information System), anxiety (Patient-Reported Outcomes Measurement Information System), and distress (Brief Symptom Inventory) at baseline (9-30 months after diagnosis) and subsequent to the intervention. Data were analyzed using multivariate general linear models. FINDINGS: Participants ranged in age from 20 to 72 years at diagnosis (mean = 43 years), 41% were Hispanic, and 52% were non-Hispanic white. Three-fourths were stage 1 at diagnosis and 51% were treated with radiation with or without chemotherapy. At baseline, 15% of patients were current smokers, 4% reported alcohol consumption of >10 drinks per week, and 63% reported exercising <3 hours per week. Overall, 67.4% of cervical cancer survivors did not meet recommended national guidelines for at least 1 of these health behaviors. QOL scores were significantly higher for patients with greater physical activity (128 vs 118; P = 0.002) and increased with the number of recommended guidelines met (P for trend = 0.030). Associations between patient-reported outcomes and smoking and alcohol consumption did not reach statistical significance. Participants who met guidelines for all health behaviors also had less depression (P = 0.008), anxiety (P = 0.051), and distress (P = 0.142). Participants who improved their aggregate health behaviors during the 4-month follow-up experienced a greater improvement in QOL than those who did not improve their health behaviors (10.8 vs 4.5; P = 0.026). IMPLICATIONS: Results indicate that two-thirds of cervical cancer survivors are not meeting national guidelines for smoking, physical activity, and alcohol consumption following completion of definitive treatment. These adverse health behaviors were associated with impaired QOL and higher levels of depression and distress. Positive changes in health behaviors are associated with significant improvement in QOL.

Psychosocial telephone counseling for survivors of cervical cancer: results of a randomized biobehavioral trial.

PURPOSE: Survivors of cervical cancer experience quality-of-life (QOL) disruptions that persist years after treatment. This study examines the effect of a psychosocial telephone counseling (PTC) intervention on QOL domains and associations with biomarkers. PATIENTS AND METHODS: We conducted a randomized clinical trial in survivors of cervical cancer, who were ≥ 9 and less than 30 months from diagnosis (n = 204), to compare PTC to usual care (UC). PTC included five weekly sessions and a 1-month booster. Patient-reported outcomes (PROs) and biospecimens were collected at baseline and 4 and 9 months after enrollment. Changes in PROs over time and associations with longitudinal change in cytokines as categorical variables were analyzed using multivariable analysis of variance for repeated measures. RESULTS: Participant mean age was 43 years; 40% of women were Hispanic, and 51% were non-Hispanic white. Adjusting for age and baseline scores, participants receiving PTC had significantly improved depression and improved gynecologic and cancer-specific concerns at 4 months compared with UC participants (all P < .05); significant differences in gynecologic and cancer-specific concerns (P < .05) were sustained at 9 months. Longitudinal change in overall QOL and anxiety did not reach statistical significance. Participants with decreasing interleukin (IL) -4, IL-5, IL-10, and IL-13 had significantly greater improvement in QOL than those with increasing cytokine levels. CONCLUSION: This trial confirms that PTC benefits mood and QOL cancer-specific and gynecologic concerns for a multiethnic underserved population of survivors of cancer. The improvement in PROs with decreases in T-helper type 2 and counter-regulatory cytokines supports a potential biobehavioral pathway relevant to cancer survivorship.

Identification and characterization of a cytotoxic T-lymphocyte agonist epitope of brachyury, a transcription factor involved in epithelial to mesenchymal transition and metastasis.

The transcription factor brachyury is a major driver of epithelial to mesenchymal transition in human carcinoma cells. It is overexpressed in several human tumor types versus normal adult tissues, except for testes and thyroid. Overexpression is associated with drug resistance and poor prognosis. Previous studies identified a brachyury HLA-A2 cytotoxic T-lymphocyte epitope. The studies reported here describe an enhancer epitope of brachyury. Compared to the native epitope, the agonist epitope: (a) has enhanced binding to MHC class I, (b) increased the IFN-γ production from brachyury-specific T cells, (c) generated brachyury-specific T cells with greater levels of perforin and increased proliferation, (d) generated T cells more proficient at lysing human carcinoma cells endogenously expressing the native epitope, and (e) achieved greater brachyury-specific T-cell responses in vivo in HLA-A2 transgenic mice. These studies also report the generation of a heat-killed recombinant Saccharomyces cerevisiae (yeast) vector expressing the full-length brachyury gene encoding the agonist epitope. Compared to yeast-brachyury (native) devoid of the agonist epitope, the yeast-brachyury (agonist) enhanced the activation of brachyury-specific T cells, which efficiently lysed human carcinoma cells. In addition to providing the rationale for the recombinant yeast-brachyury (agonist) as a potential vaccine in cancer therapy, these studies also provide the rationale for the use of the agonist in (a) dendritic cell (DC) vaccines, (b) adjuvant or liposomal vaccines, (c) recombinant viral and/or bacterial vaccines, (d) protein/polypeptide vaccines, (e) activation of T cells ex vivo in adoptive therapy protocols, and (f) generation of genetically engineered targeted T cells.

Immune impact induced by PROSTVAC (PSA-TRICOM), a therapeutic vaccine for prostate cancer.

PSA-TRICOM (PROSTVAC) is a novel vector-based vaccine designed to generate a robust immune response against prostate-specific antigen (PSA)-expressing tumor cells. The purpose of this report is to present an overview of both published studies and new data in the evaluation of immune responses to the PSA-TRICOM vaccine platform, currently in phase III testing. Of 104 patients tested for T-cell responses, 57% (59/104) demonstrated a ≥ 2-fold increase in PSA-specific T cells 4 weeks after vaccine (median 5-fold increase) compared with pre-vaccine, and 68% (19/28) of patients tested mounted post-vaccine immune responses to tumor-associated antigens not present in the vaccine (antigen spreading). The PSA-specific immune responses observed 28 days after vaccine (i.e., likely memory cells) are quantitatively similar to the levels of circulating T cells specific for influenza seen in the same patients. Measurements of systemic immune response to PSA may underestimate the true therapeutic immune response (as this does not account for cells that have trafficked to the tumor) and does not include antigen spreading. Furthermore, although the entire PSA gene is the vaccine, only one epitope of PSA is evaluated in the T-cell responses. Because this therapeutic vaccine is directed at generating a cellular/Th1 immune response (T-cell costimulatory molecules and use of a viral vector), it is not surprising that less than 0.6% of patients (2/349) tested have evidence of PSA antibody induction following vaccine. This suggests that post-vaccine PSA kinetics were not affected by PSA antibodies. An ongoing phase III study will evaluate the systemic immune responses and correlation with clinical outcomes.

A combination trial of vaccine plus ipilimumab in metastatic castration-resistant prostate cancer patients: immune correlates.

We recently reported the clinical results of a Phase I trial combining ipilimumab with a vaccine containing transgenes for prostate-specific antigen (PSA) and for a triad of costimulatory molecules (PROSTVAC) in patients with metastatic castration-resistant prostate cancer. Thirty patients were treated with escalating ipilimumab and a fixed dose of vaccine. Of 24 chemotherapy-naïve patients, 58 % had a PSA decline. Combination therapy did not exacerbate the immune-related adverse events associated with ipilimumab. Here, we present updated survival data and an evaluation of 36 immune cell subsets pre- and post-therapy. Peripheral blood mononuclear cells were collected before therapy, at 13 days and at 70 days post-initiation of therapy, and phenotyped by flow cytometry for the subsets of T cells, regulatory T cells, natural killer cells, and myeloid-derived suppressor cells. Associations between overall survival (OS) and immune cell subsets prior to treatment, and the change in a given immune cell subset 70 days post-initiation of therapy, were evaluated. The median OS was 2.63 years (1.77-3.45). There were trends toward associations for longer OS and certain immune cell subsets before immunotherapy: lower PD-1(+)Tim-3(NEG)CD4EM (P = 0.005, adjusted P = 0.010), higher PD-1(NEG)Tim-3(+)CD8 (P = 0.002, adjusted P = 0.004), and a higher number of CTLA-4(NEG) Tregs (P = 0.005, adjusted P = 0.010). We also found that an increase in Tim-3(+) natural killer cells post- versus pre-vaccination associated with longer OS (P = 0.0074, adjusted P = 0.015). These results should be considered as hypothesis generating and should be further evaluated in larger immunotherapy trials.

Identification by digital immunohistochemistry of intratumoral changes of immune infiltrates after vaccine in the absence of modifications of PBMC immune cell subsets.

Preclinical studies have demonstrated that the combination of systemic subcutaneous (s.c.) vaccination with intratumoral (i.t.) vaccination was superior in the induction of antitumor activity vs. vaccination with either route alone. A subsequent phase I study employing i.t.-s.c. vaccination was carried out in men with locally recurrent or progressive prostate cancer. rF-PSA-TRICOM (PROSTVAC) vaccine was administered intraprostatically and rV-PSA-TRICOM followed by rF-PSA-TRICOM vaccine was administered systemically. In that study no dose limiting toxicities were observed, 19/21 patients had stable or improved prostate-specific antigen (PSA) values and tumor-infiltrating lymphocytes (TILs) increased in post- vs. pre-treatment tumor biopsies, analyzed employing conventional immunohistochemistry (IHC). In the studies reported here, 31 phenotypes of peripheral blood mononuclear cells (PBMCs) were analyzed prevaccination and postvaccination as well as the functions of PBMC regulatory T cells (Tregs) and natural killer cells. A trend was observed in decreases in serum PSA with the reduction of circulating Tregs postvaccination. Digital IHC was employed prevaccination and postvaccination to measure CD4 and CD8 TILs, as well as Treg TILs by conventional IHC. Few correlations were observed with CD4, CD8 or Treg in TILs vs. PBMCs. However, patients with lower levels of CD4 TILs prevaccination showed the greatest increases in CD4 TILs postvaccine, while Treg TILs decreased postvaccine. There was also a strong correlation between decreases in serum PSA and increases in CD8 TILs postvaccine. These studies provide additional rationale for the use of i.t.-s.c. vaccinations and demonstrate a noncoordinate expression of specific immune subsets in PBMCs vs. tumor.

Identification and characterization of agonist epitopes of the MUC1-C oncoprotein.

The MUC1 tumor-associated antigen is overexpressed in the majority of human carcinomas and several hematologic malignancies. Much attention has been paid to the hypoglycosylated variable number of tandem repeats (VNTR) region of the N-terminus of MUC1 as a vaccine target, and recombinant viral vector vaccines are also being evaluated that express the entire MUC1 transgene. While previous studies have described MUC1 as a tumor-associated tissue differentiation antigen, studies have now determined that the C-terminus of MUC1 (MUC1-C) is an oncoprotein, and its expression is an indication of poor prognosis in numerous tumor types. We report here the identification of nine potential CD8⁺ cytotoxic T lymphocyte epitopes of MUC1, seven in the C-terminus and two in the VNTR region, and have identified enhancer agonist peptides for each of these epitopes. These epitopes span HLA-A2, HLA-A3, and HLA-A24 major histocompatibility complex (MHC) class I alleles, which encompass the majority of the population. The agonist peptides, compared to the native peptides, more efficiently (a) generate T-cell lines from the peripheral blood mononuclear cells of cancer patients, (b) enhance the production of IFN-γ by peptide-activated human T cells, and (c) lyse human tumor cell targets in an MHC-restricted manner. The agonist epitopes described here can be incorporated into various vaccine platforms and for the ex vivo generation of human T cells. These studies provide the rationale for the T-cell-mediated targeting of the oncogenic MUC1-C, which has been shown to be an important factor in both drug resistance and poor prognosis for numerous tumor types.

Phase I trial of a recombinant yeast-CEA vaccine (GI-6207) in adults with metastatic CEA-expressing carcinoma.

Yeast-CEA (GI-6207) is a therapeutic cancer vaccine genetically modified to express recombinant carcinoembryonic antigen (CEA) protein, using heat-killed yeast (Saccharomyces cerevisiae) as a vector. In preclinical studies, yeast-CEA induced a strong immune response to CEA and antitumor responses. Patients received subcutaneous vaccines every 2 weeks for 3 months and then monthly. Patients were enrolled at 3 sequential dose levels: 4, 16, and 40 yeast units (10(7) yeast particles/unit). Eligible patients were required to have serum CEA > 5 ng/mL or > 20 % CEA(+) tumor block, ECOG PS 0-2, and no history of autoimmunity. Restaging scans were performed at 3 months and then bimonthly. Peripheral blood was collected for the analysis of immune response (e.g., by ELISPOT assay). Twenty-five patients with metastatic CEA-expressing carcinomas were enrolled. Median patient age was 52 (range 39-81). A total of 135 vaccines were administered. The vaccine was well tolerated, and the most common adverse event was grade 1/2 injection-site reaction. Five patients had stable disease beyond 3 months (range 3.5-18 months), and each had CEA stabilization while on-study. Some patients showed evidence post-vaccination of increases in antigen-specific CD8(+) T cells and CD4(+) T lymphocytes and decreases in regulatory T cells. Of note, a patient with medullary thyroid cancer had substantial T cell responses and a vigorous inflammatory reaction at sites of metastatic disease. Yeast-CEA vaccination had minimal toxicity and induced some antigen-specific T cell responses and CEA stabilization in a heterogeneous, heavily pre-treated patient population. Further studies are required to determine the clinical benefit of yeast-CEA vaccination.

Effect of talactoferrin alfa on the immune system in adults with non-small cell lung cancer.

BACKGROUND: Talactoferrin alfa (talactoferrin), an agent with immune-stimulating properties, has demonstrated safety and preliminary efficacy in clinical trials. METHODS: Ten patients (five males and five females) with stage IV non-small cell lung cancer (NSCLC) in a single-arm pilot study received orally administered talactoferrin (1.5 g, b.i.d.) for up to 24 weeks. Radiographic and immunologic studies were performed at baseline and at weeks 6 and 12. Circulating immune cells (natural killer cells [NKCs], CD4+, CD8+, and regulatory T cells) and systemic cytokine levels were measured to assess immune response. RESULTS: Patients enrolled in the study had received a median of four prior chemotherapy regimens, and all patients were symptomatic. Talactoferrin was well tolerated, with no grade 3 or 4 toxicities. Median time to progression (TTP) and overall survival were 6 weeks and 14.5 weeks, respectively. The four patients with ≥9 weeks TTP had evidence of immunologic activity (three with increased NKC activity). CONCLUSIONS: The median of four previous chemotherapy regimens, with elevated levels of interleukin (IL) 6 and tumor necrosis factor-alfa in most patients, suggests these patients were poor candidates for immunotherapy.

Up-regulation of proliferative and migratory genes in regulatory T cells from patients with metastatic castration-resistant prostate cancer.

A higher frequency of regulatory T cells (Tregs) has been observed in peripheral blood mononuclear cells (PBMC) of patients with different types of solid tumors and hematological malignancies as compared to healthy donors. In prostate cancer patients, Tregs in PBMC have been shown to have increased suppressive function. Tumor-induced biological changes in Tregs may enable tumor cells to escape immunosurveillance. We performed genome-wide expression analyses comparing the expression levels of more than 38,500 genes in Tregs with similar suppressive activity, isolated from the peripheral blood of healthy donors and patients with metastatic castration-resistant prostate cancer (mCRPC). The differentially expressed genes in mCRPC Tregs are involved in cell cycle processes, cellular growth and proliferation, immune responses, hematological system development and function and the interleukin-2 (IL-2) and transforming growth factor-ß (TGF-ß) pathways. Studies revealed that the levels of expression of genes responsible for T-cell proliferation (C-FOS, C-JUN and DUSP1) and cellular migration (RGS1) were greater in Tregs from mCRPC patients as compared to values observed in healthy donors. Increased RGS1 expression in Tregs from mCRPC patients suggests a decrease in these Tregs' migratory ability. In addition, the higher frequency of CD4(+) CD25(high) CD127(-) Tregs in the peripheral blood of mCRPC patients may be the result of an increase in Treg proliferation capacity. Results also suggest that the alterations observed in gene expression profiles of Tregs in mCRPC patients may be part of the mechanism of tumor escape from host immune surveillance.

Immunotherapy: shifting the balance of cell-mediated immunity and suppression in human prostate cancer.

Active immunotherapy is dependent on the ability of the immune system to recognize and respond to tumors. Despite overwhelming evidence to support a cell-mediated immune response to prostate cancer, it is insufficient to eradicate the disease. This is likely due to a high level of suppression at the tumor site from a variety of sources, including immunosuppressive cells. Immune cells entering the tumor microenvironment may be inhibited directly by the tumor, stromal cells or other immune cells that have been induced to adopt a suppressive phenotype. The resurgence of interest in immunotherapy following the approval of sipuleucel-T and ipilimumab by the Food and Drug Administration has brought about new strategies for overcoming tumor-mediated suppression and bolstering anti-tumor responses. Improved understanding of the immune response to prostate cancer can lead to new combination therapies, such as the use of vaccine with small molecule and checkpoint inhibitors or other immunotherapies.

Characteristics of PBMC obtained from leukapheresis products and tumor biopsies of patients with non-small cell lung cancer.

The current study characterized peripheral blood mononuclear cells (PBMC) obtained from leukapheresis products of patients with non-small cell lung cancer (NSCLC) for cytokine release, the ability to incorporate tritiated thymidine following stimulation using PHA as well as the levels of both CD4 and CD8 regulatory T cells (Tregs) as defined by FoxP3 expression. Results were compared to normal donor PBMC obtained from buffy coat products. Heterogeneous levels of Th1 (gamma interferon and IL-2), Th2 (IL-10 and IL-13), pro-inflammatory (TNF-alpha and IL-6) and the hematopoietic inducing cytokine GMCSF were detected from both populations of PBMC as measured using ELISA. Overall, we observed that combined levels of Th1 and Th2 cytokines were higher in lung cancer patients compared to that seen in normal donor PBMC. The increased cytokine production was coupled with an observed decrease in the ability of lung cancer patient PBMC to incorporate tritiated thymidine. Furthermore, cytokine containing supernatants obtained from patients inhibited the incorporation of tritiated thymidine from PBMC obtained from normal donors. Thus, the combined cytokines which included high levels of IL-10, appeared to exhibit suppressive functional activity. While not statistically significant, the overall trend toward a Th2 cytokine environment was supported by an increased level of Tregs observed in the leukapheresis products of lung cancer patients. These levels were variable and were accompanied by higher than normal levels of CD8+ cells co-expressing FoxP3. Finally, tumor biopsies were examined from lung cancer patients along with autologous normal adjacent tissue (NAT). In these studies, both gamma interferon and IL-10 were detected. The levels of IL-10 in the LPS stimulated cultures were statistically greater from the cancer biopsies compared to the NAT. The current study confirms many earlier results in a comprehensive manner and extends the analysis to leukapheresis products. An environment is described in cancer patients which is characterized by increased cytokine production and decreased proliferative potential likely under the influence of a significant population of regulatory T cells (Tregs). Taken together, these results are discussed as they relate to the potential implications in lung cancer patients immune response to their disease.