ABSTRACT
Tumor-targeting Abs can be used to initiate an antitumor immune program, which appears essential to achieve a long-term durable clinical response to cancer. We previously identified an anti-complement factor H (CFH) autoantibody associated with patients with early-stage non-small cell lung cancer. We cloned from their peripheral B cells an mAb, GT103, that specifically recognizes CFH on tumor cells. Although the underlying mechanisms are not well defined, GT103 targets a conformationally distinct CFH epitope that is created when CFH is associated with tumor cells, kills tumor cells in vitro, and has potent antitumor activity in vivo. In the effort to better understand how an Ab targeting a tumor epitope can promote an effective antitumor immune response, we used the syngeneic CMT167 lung tumor C57BL/6 mouse model, and we found that murinized GT103 (mGT103) activates complement and enhances antitumor immunity through multiple pathways. It creates a favorable tumor microenvironment by decreasing immunosuppressive regulatory T cells and myeloid-derived suppressor cells, enhances Ag-specific effector T cells, and has an additive antitumor effect with anti-PD-L1 mAb. Furthermore, the immune landscape of tumors from early-stage patients expressing the anti-CFH autoantibody is associated with an immunologically active tumor microenvironment. More broadly, our results using an mAb cloned from autoantibody-expressing B cells provides novel, to our knowledge, mechanistic insights into how a tumor-specific, complement-activating Ab can generate an immune program to kill tumor cells and inhibit tumor growth.
Subject(s)
Complement Activation , Mice, Inbred C57BL , Animals , Mice , Humans , Complement Activation/immunology , Cell Line, Tumor , Complement Factor H/immunology , Tumor Microenvironment/immunology , Lung Neoplasms/immunology , Lung Neoplasms/therapy , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , Autoantibodies/immunology , Carcinoma, Non-Small-Cell Lung/immunology , Carcinoma, Non-Small-Cell Lung/therapy , Female , T-Lymphocytes, Regulatory/immunologyABSTRACT
Intratumoral B lymphocytes are an integral part of the lung tumor microenvironment. Interrogation of the antibodies they express may improve our understanding of the host response to cancer and could be useful in elucidating novel molecular targets. We used two strategies to explore the repertoire of intratumoral B cell antibodies. First, we cloned VH and VL genes from single intratumoral B lymphocytes isolated from one lung tumor, expressed the genes as recombinant mAbs, and used the mAbs to identify the cognate tumor antigens. The Igs derived from intratumoral B cells demonstrated class switching, with a mean VH mutation frequency of 4%. Although there was no evidence for clonal expansion, these data are consistent with antigen-driven somatic hypermutation. Individual recombinant antibodies were polyreactive, although one clone demonstrated preferential immunoreactivity with tropomyosin 4 (TPM4). We found that higher levels of TPM4 antibodies were more common in cancer patients, but measurement of TPM4 antibody levels was not a sensitive test for detecting cancer. Second, in an effort to focus our recombinant antibody expression efforts on those B cells that displayed evidence of clonal expansion driven by antigen stimulation, we performed deep sequencing of the Ig genes of B cells collected from seven different tumors. Deep sequencing demonstrated somatic hypermutation but no dominant clones. These strategies may be useful for the study of B cell antibody expression, although identification of a dominant clone and unique therapeutic targets may require extensive investigation.
Subject(s)
B-Lymphocyte Subsets/immunology , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Lymphocytes, Tumor-Infiltrating/immunology , Aged , Amino Acid Sequence , Antibodies/chemistry , Antibodies/genetics , Antibodies/immunology , Antibodies/isolation & purification , Antigens, Neoplasm/immunology , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , B-Lymphocyte Subsets/metabolism , Case-Control Studies , Clonal Evolution/genetics , Clonal Evolution/immunology , Cloning, Molecular , Female , Gene Expression , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Lymphocytes, Tumor-Infiltrating/metabolism , Male , Middle Aged , Molecular Sequence Data , Molecular Targeted Therapy , Neoplasm Staging , Sequence Alignment , Sequence Analysis, DNAABSTRACT
RATIONALE: Indeterminate pulmonary nodules are a common radiographic finding and require further evaluation because of the concern for lung cancer. OBJECTIVES: We developed an algorithm to assign patients to a low- or high-risk category for lung cancer, based on a combination of serum biomarker levels and nodule size. METHODS: For the serum biomarker assay, we determined levels of carcinoembryonic antigen, α1-antitrypsin, and squamous cell carcinoma antigen. Serum data and nodule size from a training set of 509 patients with (n = 298) and without (n = 211) lung cancer were subjected to classification and regression tree and logistic regression analyses. Multiple models were developed and tested in an independent, masked validation set for their ability to categorize patients with (n = 203) or without (n = 196) lung cancer as being low- or high-risk for lung cancer. MEASUREMENTS AND MAIN RESULTS: In all models, a large percentage of individuals in the validation study with small nodules (<1 cm) were assigned to the low-risk group, and a large percentage of individuals with large nodules (≥3 cm) were assigned to the high-risk group. In the validation study, the classification and regression tree algorithm had overall sensitivity, specificity, and positive and negative predictive values for determining lung cancer of 88%, 82%, 84%, and 87%, respectively. The logistic regression model had overall sensitivity, specificity, and positive and negative predictive values of 80%, 89%, 89%, and 81%, respectively. CONCLUSION: Integration of biomarkers with lung nodule size has the potential to help guide the management of patients with indeterminate pulmonary nodules.
Subject(s)
Biomarkers/blood , Lung Diseases/diagnosis , Lung Neoplasms/diagnosis , Solitary Pulmonary Nodule/blood , Solitary Pulmonary Nodule/therapy , Adult , Aged , Aged, 80 and over , Algorithms , Antigens, Neoplasm/blood , Carcinoembryonic Antigen/blood , Diagnosis, Differential , Female , Humans , Logistic Models , Male , Middle Aged , Sensitivity and Specificity , Serpins/blood , alpha 1-Antitrypsin/bloodABSTRACT
The elimination of cancer cells critically depends on the immune system. However, cancers have evolved a variety of defense mechanisms to evade immune monitoring, leading to tumor progression. Complement factor H (CFH), predominately known for its function in inhibiting the alternative pathway of the complement system, has recently been identified as an important innate immunological checkpoint in cancer. CFH-mediated immunosuppression enhances tumor cells' ability to avoid immune recognition and produce an immunosuppressive tumor microenvironment. This review explores the molecular underpinnings, interactions with immune cells, clinical consequences, and therapeutic possibilities of CFH as an innate immune checkpoint in cancer control. The difficulties and opportunities of using CFH as a target in cancer immunotherapy are also explored.
ABSTRACT
Development of novel therapeutic antibodies that not only kill tumor cells but modulate the adaptive immune response has the potential to produce long term anticancer immunity and a durable clinical response. We previously reported the discovery of anti-complement factor H (CFH) autoantibodies in patients with lung cancer that were associated with early-stage disease and exceptional outcomes. The human mAb GT103, produced from a single CFH autoantibody-expressing B cell of a patient with lung cancer, recognizes a conformationally distinct epitope on tumor cells, kills tumor cells, and inhibits tumor growth in animal studies. Recent experiments have shown that GT103 restructures the tumor microenvironment and initiates a robust antitumoral adaptive immune response. The current study further elucidates several mechanisms by which GT103 kills tumor cells and drives the immune program. Here we show GT103 has specificity for tumor cells without binding to native soluble CFH or normal tissues. GT103 causes complement C3 split product deposition on tumor cells in vitro and in vivo, triggers antibody-dependent cellular phagocytosis, and increases translocation of the danger-associated molecular pattern molecule calreticulin to the plasma membrane. We also demonstrate that GT103 causes B-cell activation in vitro and in vivo, and that GT103 antitumor activity in vivo is B-cell dependent. The complex mechanism of GT103, a tumor-specific antibody that kills tumor cells and stimulates an immune response, supports further development of this human-derived antibody as a novel therapeutic option for patients with lung cancer.
Subject(s)
Antineoplastic Agents , Lung Neoplasms , Animals , Humans , Complement Factor H/therapeutic use , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Lung Neoplasms/pathology , Autoantibodies/therapeutic use , Antineoplastic Agents/therapeutic use , Tumor MicroenvironmentABSTRACT
BACKGROUND: Patients with advanced stage adenocarcinoma of the pancreas have a poor prognosis. The identification of prognostic and/or predictive biomarkers may help stratify patients so that therapy can be individualized. METHODS: Serum samples from patients enrolled in the Cancer and Leukemia Group B 80303 phase 3 trial, "Randomized Study of Gemcitabine With Versus Without Bevacizumab in Patients With Locally Advanced or Metastatic Adenocarcinoma of the Pancreas" were used to discover novel biomarkers. For the discovery phase, 40 sera were selected based on length of survival and type of therapy, and subjected to liquid chromatography coupled to tandem mass spectrometry analysis (LC-MS-MS). The top features (proteins) were then further selected for validation by enzyme-linked immunosorbent assay (ELISA). RESULTS: Quantification by nano-LC-MS-MS resulted in 1452 peptides mapping to 156 proteins across all 40 samples, 92 of which had 2 or more peptides. After curation of the data, the authors selected 1 putative prognostic protein, alpha 1-antichymotrypsin (AACT), and 2 putative predictive proteins, histidine-rich glycoprotein (HRG) and complement factor H (CFH), for validation by ELISA. AACT was found to be negatively correlated with overall survival (τ = -0.30 [-0.38, -0.22]; P < .00001). There was no evidence for interaction with bevacizumab and HRG, but there was some evidence for a weak positive correlation of HRG with overall survival (τ = 0.11 [0.03, 0.19]; P < .01). CFH was found to be neither a predictive nor a prognostic factor for overall survival. CONCLUSIONS: AACT may be a useful prognostic marker in patients with advanced stage pancreatic carcinoma, although additional validation studies are needed.
Subject(s)
Adenocarcinoma/diagnosis , Biomarkers, Tumor/blood , Pancreatic Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Clinical Trials, Phase III as Topic , Female , Humans , Male , Middle Aged , Prognosis , alpha 1-Antichymotrypsin/bloodABSTRACT
BACKGROUND: Biomarkers that predict which patients with early stage NSCLC will develop recurrent disease would be of clinical value. We previously discovered that an autoantibody to a complement regulatory protein, complement factor H (CFH), is associated with early stage, non-recurrent NSCLC, and hypothesized that the anti-CFH antibody inhibits metastasis. OBJECTIVES: The primary objective of this study was to evaluate the anti-CFH antibody as a prognostic marker for recurrence in stage I NSCLC. A secondary objective was to determine if changes in antibody serum level one year after resection were associated with recurrence. METHODS: Anti-CFH antibody was measured in the sera of 157 stage I NSCLC patients designated as a prognostic cohort: 61% whose cancers did not recur, and 39% whose cancers recurred following resection. Impact of anti-CFH antibody positivity on time to recurrence was assessed using a competing risk analysis. Anti-CFH antibody levels were measured before resection and one year after resection in an independent temporal cohort of 47 antibody-positive stage I NSCLC patients: 60% whose cancers did not recur and 40% whose cancers recurred following resection. The non-recurrent and recurrent groups were compared with respect to the one-year percent change in antibody level. RESULTS: In the prognostic cohort, the 60-month cumulative incidence of recurrence was 40% and 22% among antibody negative and positive patients, respectively; this difference was significant (Gray's test, P= 0.0425). In the temporal cohort, the antibody persisted in the serum at one year post-tumor resection. The change in antibody levels over the one year period was not statistically different between the non-recurrent and recurrent groups (Wilcoxon two-sample test, P= 0.4670). CONCLUSIONS: The anti-CFH autoantibody may be a useful prognostic marker signifying non-recurrence in early stage NSCLC patients. However, change in the level of this antibody in antibody-positive patients one year after resection had no association with recurrence.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Autoantibodies , Carcinoma, Non-Small-Cell Lung/pathology , Complement Factor H , Humans , Lung Neoplasms/pathology , Neoplasm Recurrence, Local/pathology , PrognosisABSTRACT
Introduction: In vivo, cancer cells respond to signals from the tumor microenvironment resulting in changes in expression of proteins that promote tumor progression and suppress anti-tumor immunity. This study employed an orthotopic immunocompetent model of lung cancer to define pathways that are altered in cancer cells recovered from tumors compared to cells grown in culture. Methods: Studies used four murine cell lines implanted into the lungs of syngeneic mice. Cancer cells were recovered using FACS, and transcriptional changes compared to cells grown in culture were determined by RNA-seq. Results: Changes in interferon response, antigen presentation and cytokine signaling were observed in all tumors. In addition, we observed induction of the complement pathway. We previously demonstrated that activation of complement is critical for tumor progression in this model. Complement can play both a pro-tumorigenic role through production of anaphylatoxins, and an anti-tumorigenic role by promoting complement-mediated cell killing of cancer cells. While complement proteins are produced by the liver, expression of complement proteins by cancer cells has been described. Silencing cancer cell-specific C3 inhibited tumor growth In vivo. We hypothesized that induction of complement regulatory proteins was critical for blocking the anti-tumor effects of complement activation. Silencing complement regulatory proteins also inhibited tumor growth, with different regulatory proteins acting in a cell-specific manner. Discussion: Based on these data we propose that localized induction of complement in cancer cells is a common feature of lung tumors that promotes tumor progression, with induction of complement regulatory proteins protecting cells from complement mediated-cell killing.
ABSTRACT
Exosomes are a class of extracellular vesicles (EVs) that are mediators of normal intercellular communication, but exosomes are also used by tumor cells to promote oncogenesis and metastasis. Complement factor H (CFH) protects host cells from attack and destruction by the alternative pathway of complement-dependent cytotoxicity (CDC). Here we show that CFH can protect exosomes from complement-mediated lysis and phagocytosis. CFH was found to be associated with EVs from a variety of tumor cell lines as well as EVs isolated from the plasma of patients with metastatic non-small cell lung cancer. Higher levels of CFH-containing EVs correlated with higher metastatic potential of cell lines. GT103, a previously described antibody to CFH that preferentially causes CDC of tumor cells, was used to probe the susceptibility of tumor cell-derived exosomes to destruction. Exosomes were purified from EVs using CD63 beads. Incubation of GT103 with tumor cell-derived exosomes triggered exosome lysis primarily by the classical complement pathway as well as antibody-dependent exosome phagocytosis by macrophages. These results imply that GT103-mediated exosome destruction can be triggered by antibody Fc-C1q interaction (in the case of lysis), and antibody-Fc receptor interactions (in the case of phagocytosis). Thus, this work demonstrates CFH is expressed on tumor cell derived exosomes, can protect them from complement lysis and phagocytosis, and that an anti-CFH antibody can be used to target tumor-derived exosomes for exosome destruction via innate immune mechanisms. These findings suggest that a therapeutic CFH antibody has the potential to inhibit tumor progression and reduce metastasis promoted by exosomes.
Subject(s)
Complement Factor H/metabolism , Exosomes/metabolism , Macrophages/immunology , Phagocytosis/physiology , Antibodies/immunology , Antibodies/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Complement Factor H/immunology , Humans , Immunity, Innate , Leukocytes, Mononuclear/cytology , Lung Neoplasms/pathology , Macrophages/cytology , Macrophages/metabolism , Membrane Glycoproteins/metabolism , Neoplasm Staging , Receptors, Complement/metabolism , Tumor Cells, CulturedABSTRACT
BACKGROUND: Single nucleotide polymorphisms (SNPs) are often associated with distinct phenotypes in cancer. The present study investigated associations of cancer risk and outcomes with SNPs discovered by whole exome sequencing of normal lung tissue DNA of 15 non-small cell lung cancer (NSCLC) patients, 10 early stage and 5 advanced stage. METHODS: DNA extracted from normal lung tissue of the 15 NSCLC patients was subjected to whole genome amplification and sequencing and analyzed for the occurrence of SNPs. The association of SNPs with the risk of lung cancer and survival was surveyed using the OncoArray study dataset of 85,716 patients (29,266 cases and 56,450 cancer-free controls) and the Prostate, Lung, Colorectal and Ovarian study subset of 1,175 lung cancer patients. RESULTS: We identified 4 SNPs exclusive to the 5 patients with advanced stage NSCLC: rs10420388 and rs10418574 in the CLPP gene, and rs11126435 and rs2021725 in the M1AP gene. The variant alleles G of SNP rs10420388 and A of SNP rs10418574 in the CLPP gene were associated with increased risk of squamous cell carcinoma (OR = 1.07 and 1.07; P = 0.013 and 0.016, respectively). The variant allele T of SNP rs11126435 in the M1AP gene was associated with decreased risk of adenocarcinoma (OR = 0.95; P = 0.027). There was no significant association of these SNPs with the overall survival of lung cancer patients (P > 0.05). CONCLUSIONS: SNPs identified in the CLPP and M1AP genes may be useful in risk prediction models for lung cancer. The previously established association of the CLPP gene with cancer progression lends relevance to our findings.
ABSTRACT
A protease digestion strategy was incorporated into single-point stability of unpurified proteins from rates of H/D exchange (SUPREX), which is a hydrogen/deuterium (H/D) exchange- and mass spectrometry-based assay for the detection of protein-ligand binding. Single-point SUPREX is an abbreviated form of SUPREX in which protein-ligand binding interactions are detected by measuring the increase in a protein's thermodynamic stability upon ligand binding. The new protease digestion protocol provides a noteworthy increase in the efficiency of single-point SUPREX because peptide masses can be determined with greater precision than intact protein masses in the matrix-assisted laser desorption ionization (MALDI) readout of single-point SUPREX. The protocol was evaluated in test screens on two model protein systems, including cyclophilin A (CypA) and the minor allele variant of human alanine:glyoxylate aminotransferase (AGTmi). The test screening results obtained on both proteins revealed that the peptide readout of the single-point SUPREX-protease digestion protocol was more efficient than the intact protein readout of the original single-point SUPREX protocol at discriminating hits and nonhits. In addition to this improvement in screening efficiency, the protease digestion strategy described here is expected to significantly increase the generality of the single-point SUPREX assay.
Subject(s)
Deuterium/metabolism , Hydrogen/metabolism , Peptide Hydrolases/metabolism , Proteins/metabolism , Ligands , Mass Spectrometry , ThermodynamicsABSTRACT
Epidermal growth factor receptor (EGFR) is overexpressed or mutated in a high percentage of tumors. EGFR has long been considered a promising target for cancer diagnostic and therapeutic applications. However, monoclonal antibodies and other large antibody constructs diffuse into tumors slowly, limiting their efficacy. To develop lower molecular weight probes for EGFR and other tumor cell receptors, the authors immunized a llama with the extracellular domains (ECDs) of EGFR and an oncogenic mutant receptor, EGFRvIII, and with extracts of tumor cell lines. From the immune repertoire of the llama, the authors constructed a heavy chain variable domain (VHH domain)-phage library. At approximately 16 kDa, the VHH domain is a tenth of the size of a monoclonal antibody and is the smallest antibody fragment that retains specificity. By affinity selection from this library, the authors isolated many VHH domains with specificity for EGFR. The VHH domains bind to whole cells expressing the receptor but not to control cells lacking the receptor and can immunoprecipitate EGFR from cell lysates. Some VHH domains have cross-specificity with existing anti-EGFR monoclonal antibodies and have reasonably high (nM) affinities. The llama-VHH domain library is also potentially a rich source of targeting agents directed toward other tumor cell receptors.
Subject(s)
ErbB Receptors/isolation & purification , Peptide Fragments/isolation & purification , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , Antibody Specificity , Cell Line , Cross Reactions/immunology , Enzyme-Linked Immunosorbent Assay , ErbB Receptors/chemistry , ErbB Receptors/genetics , ErbB Receptors/metabolism , Humans , Immunoprecipitation , Kinetics , Mice , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Phylogeny , Sequence Alignment , Surface Plasmon Resonance , ThermodynamicsABSTRACT
Introduction: Indeterminate pulmonary lesions (IPL) detected by CT pose a significant clinical challenge, frequently necessitating long-term surveillance or biopsy for diagnosis. In this pilot investigation, we performed whole exome sequencing (WES) of plasma cell free (cfDNA) and matched germline DNA in patients with CT-detected pulmonary lesions to determine the feasibility of somatic cfDNA mutations to differentiate benign from malignant pulmonary nodules. Methods: 33 patients with a CT-detected pulmonary lesions were retrospectively enrolled (n = 16 with a benign nodule, n = 17 with a malignant nodule). Following isolation and amplification of plasma cfDNA and matched peripheral blood mononuclear cells (PBMC) from patient blood samples, WES of cfDNA and PBMC DNA was performed. After genomic alignment and filtering, we looked for lung-cancer associated driver mutations and next identified high-confidence somatic variants in both groups. Results: Somatic cfDNA mutations were observed in both groups, with the cancer group demonstrating more variants than the benign group (1083 ± 476 versus 553 ± 519, p < 0.0046). By selecting variants present in >2 cancer patients and not the benign group, we accurately identified 82% (14/17) of cancer patients. Conclusions: This study suggests a potential role for cfDNA for the early identification of lung cancer in patients with CT-detected pulmonary lesions. Importantly, a substantial number of somatic variants in healthy patients with benign pulmonary nodules were also found. Such "benign" variants, while largely unexplored to date, have widespread relevance to all liquid biopsies if cfDNA is to be used accurately for cancer detection.
ABSTRACT
An H/D exchange- and MALDI mass spectrometry-based screening assay was applied to search for novel ligands that bind to cyclophilin A, a potential therapeutic and diagnostic target in lung cancer. The assay is based on stability of unpurified proteins from rates of H/D exchange (SUPREX), which exploits the H/D exchange properties of amide protons to measure the increase in a protein's thermodynamic stability upon ligand binding in solution. The current study evaluates the throughput and efficiency with which 880 potential ligands from the Prestwick Chemical Library (Illkirch, France) could be screened for binding to cyclophilin A. Screening was performed at a rate of 3 min/ligand using a conventional MALDI mass spectrometer. False positive and false negative rates, based on a set of control data, were as low as 0% and 9%, respectively. Based on the 880-member library screening, a false positive rate of 0% was observed when a two-tier selection strategy was implemented. Although novel ligands for cyclophilin A were not discovered, cyclosporin A, a known ligand to CypA and a blind control in the library, was identified as a hit. We also describe a new strategy to eliminate some of the complications related to back exchange that can arise in screening applications of SUPREX.
Subject(s)
Combinatorial Chemistry Techniques/methods , Cyclophilin A/chemistry , Deuterium Exchange Measurement/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Binding Sites , Cyclophilin A/analysis , Cyclosporine/chemistry , Deuterium/chemistry , Humans , Immunosuppressive Agents/chemistry , Ligands , Predictive Value of Tests , Protein BindingABSTRACT
Cyclophilin A (CypA) was recently reported to be overexpressed in non-small-cell lung cancer, and represents a potentially novel therapeutic target. To determine the role of CypA in oncogenesis, stable RNA interference (RNAi)-mediated knockdown of CypA was established in two non-small-cell lung cancer cell lines (ADLC-5M2 and LC-103H), and these cells were grown as xenografts in severe combined immunodeficient mice. Tumor cell proliferation, apoptosis, and angiogenesis were measured by Ki67, terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling, and CD31 immunohistochemistry, respectively. Tumor glucose metabolism was assessed by fluorodeoxyglucose positron emission tomography imaging. Knockdown of CypA correlated in vivo with slower growth, less fluorodeoxyglucose uptake, decreased proliferation, and a greater degree of apoptosis in the tumors. These results establish the relevance of CypA to tumor growth in vivo, specifically to proliferation and apoptosis. Elucidation of the precise role of CypA in these pathways may lead to new targeted therapies for lung cancer.
Subject(s)
Carcinoma, Non-Small-Cell Lung/pathology , Cyclophilin A/antagonists & inhibitors , Lung Neoplasms/pathology , RNA Interference , Animals , Apoptosis/physiology , Carcinoma, Non-Small-Cell Lung/blood supply , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Growth Processes/physiology , Cell Line, Tumor , Cyclophilin A/biosynthesis , Cyclophilin A/genetics , Fluorodeoxyglucose F18/pharmacokinetics , Lung Neoplasms/blood supply , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Mice , Mice, Nude , Neovascularization, Pathologic/metabolism , TransfectionABSTRACT
INTRODUCTION: Most pulmonary nodules found on imaging studies are indeterminate, but because of the concern for lung cancer, all patients require further evaluation with resultant radiation risk, significant cost, and delays in diagnosis. We hypothesized that a diagnostic blood test based on detection of autoantibodies against cancer antigens would be able to distinguish a benign nodule from lung cancer. METHODS: We identified a panel of 25 serum autoantibodies associated with NSCLC and constructed a protein microarray containing the autoantigens. We tested the microarray with human sera (from 125 patients with NSCLC and 125 matched controls with a benign nodule) and attempted to develop a classification algorithm that would separate the two groups. RESULTS: In the training data set the logistic regression c-index statistic was 0.691; in the validation data set, the model predicting the score generated from the training set model had a c-index of 0.490. The relationship between the score and outcome (final diagnosis) was not statistically significant (p = 0.460). CONCLUSIONS: When the current panel of antigens and assay format was used, classification algorithms based on levels of autoantibodies to cancer antigens did not prove to have statistically significant value for predicting the presence of cancer. We suggest that there are inherent biological limitations to this approach.
Subject(s)
Antigens, Neoplasm/immunology , Autoantibodies/blood , Biomarkers, Tumor/blood , Carcinoma, Non-Small-Cell Lung/diagnosis , Lung Neoplasms/diagnosis , Algorithms , Carcinoma, Non-Small-Cell Lung/blood , Carcinoma, Non-Small-Cell Lung/immunology , Humans , Lung Neoplasms/blood , Lung Neoplasms/immunology , Prognosis , Protein Array AnalysisABSTRACT
Rituximab therapy for B cell chronic lymphocytic leukemia (B-CLL) has met with mixed success. Among several factors to which resistance can be attributed is failure to activate complement dependent cytotoxicity (CDC) due to protective complement regulatory proteins, including the soluble regulator complement factor H (CFH). We hypothesized that rituximab killing of non-responsive B-CLL cells could be augmented by a novel human monoclonal antibody against CFH. The B cells from 11 patients with B-CLL were tested ex vivo in CDC assays with combinations of CFH monoclonal antibody, rituximab, and a negative control antibody. CDC of rituximab non-responsive malignant B cells from CLL patients could in some cases be augmented by the CFH monoclonal antibody. Antibody-mediated cytotoxicity of cells was dependent upon functional complement. In one case where B-CLL cells were refractory to CDC by the combination of rituximab plus CFH monoclonal antibody, additionally neutralizing the membrane complement regulatory protein CD59 allowed CDC to occur. Inhibiting CDC regulatory proteins such as CFH holds promise for overcoming resistance to rituximab therapy in B-CLL.
Subject(s)
Antibodies/therapeutic use , Antineoplastic Agents/therapeutic use , Complement Factor H/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Rituximab/therapeutic use , Aged , Aged, 80 and over , Antibodies/immunology , Complement Activation/drug effects , Complement Activation/immunology , Female , Flow Cytometry , Humans , Male , Middle AgedABSTRACT
Current diagnostic and therapeutic strategies for lung cancer have had no significant impact on lung cancer mortality over the last several decades. This study used a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) discovery platform to generate protein expression profiles in search of overexpressed proteins in lung tumors as potentially novel molecular targets. Two differentially expressed protein peaks at m/z 12338 and 17882 in the MALDI-TOF spectra were identified in lung tumor specimens as macrophage migration inhibitory factor and cyclophilin A, respectively. Overexpression of both proteins was confirmed by Western blotting, and cyclophilin A was localized to the tumor cells by immunohistochemistry. These data demonstrate the feasibility of using a MALDI-TOF platform to generate protein expression profiles and identify potential molecular targets for cancer diagnostics and therapeutics.
Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Cyclophilin A/biosynthesis , Lung Neoplasms/metabolism , Macrophage Migration-Inhibitory Factors/biosynthesis , Amino Acid Sequence , Carcinoma, Non-Small-Cell Lung/genetics , Cyclophilin A/genetics , Gene Expression Profiling , Humans , Immunoblotting , Immunohistochemistry , Lung Neoplasms/genetics , Macrophage Migration-Inhibitory Factors/genetics , Male , Middle Aged , Molecular Sequence Data , Peptide Mapping , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
UNLABELLED: In contrast to its inhibitory effects on many cells, IL10 activates CD8(+) tumor-infiltrating lymphocytes (TIL) and enhances their antitumor activity. However, CD8(+) TILs do not routinely express IL10, as autocrine complement C3 inhibits IL10 production through complement receptors C3aR and C5aR. CD8(+) TILs from C3-deficient mice, however, express IL10 and exhibit enhanced effector function. C3-deficient mice are resistant to tumor development in a T-cell- and IL10-dependent manner; human TILs expanded with IL2 plus IL10 increase the killing of primary tumors in vitro compared with IL2-treated TILs. Complement-mediated inhibition of antitumor immunity is independent of the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) immune checkpoint pathway. Our findings suggest that complement receptors C3aR and C5aR expressed on CD8(+) TILs represent a novel class of immune checkpoints that could be targeted for tumor immunotherapy. Moreover, incorporation of IL10 in the expansion of TILs and in gene-engineered T cells for adoptive cell therapy enhances their antitumor efficacy. SIGNIFICANCE: Our data suggest novel strategies to enhance immunotherapies: a combined blockade of complement signaling by antagonists to C3aR, C5aR, and anti-PD-1 to enhance anti-PD-1 efficacy; a targeted IL10 delivery to CD8(+) TILs using anti-PD-1-IL10 or anti-CTLA4-IL10 fusion proteins; and the addition of IL10 in TIL expansion for adoptive cellular therapy. Cancer Discov; 6(9); 1022-35. ©2016 AACR.See related commentary by Peng et al., p. 953This article is highlighted in the In This Issue feature, p. 932.
Subject(s)
Autocrine Communication , Complement System Proteins/immunology , Interleukin-10/metabolism , Neoplasms/immunology , Neoplasms/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Cluster Analysis , Complement C3/immunology , Complement C3/metabolism , Disease Models, Animal , Disease Progression , Gene Expression , Gene Expression Profiling , Humans , Immunomodulation , Interleukin-10/genetics , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Mice , Mice, Knockout , Neoplasms/genetics , Neoplasms/pathology , Programmed Cell Death 1 Receptor/metabolism , Signal Transduction , Xenograft Model Antitumor AssaysABSTRACT
Some patients with cancer never develop metastasis, and their host response might provide cues for innovative treatment strategies. We previously reported an association between autoantibodies against complement factor H (CFH) and early-stage lung cancer. CFH prevents complement-mediated cytotoxicity (CDC) by inhibiting formation of cell-lytic membrane attack complexes on self-surfaces. In an effort to translate these findings into a biologic therapy for cancer, we isolated and expressed DNA sequences encoding high-affinity human CFH antibodies directly from single, sorted B cells obtained from patients with the antibody. The co-crystal structure of a CFH antibody-target complex shows a conformational change in the target relative to the native structure. This recombinant CFH antibody causes complement activation and release of anaphylatoxins, promotes CDC of tumor cell lines, and inhibits tumor growth in vivo. The isolation of anti-tumor antibodies derived from single human B cells represents an alternative paradigm in antibody drug discovery.