The biography of the immune system and the control of cancer: from St Peregrine to contemporary vaccination strategies

Hypothesis: hematogenous metastatic cancer cells of solid tumors may disguise themselves as memory macrophages for metastasis

German pathologist Otto Aichel suggested, a century ago, that the cancer cell acquired its metastatic property from a leukocyte via cell-cell fusion. Since then, several revised versions of this theory have been proposed. Most of the proposals attribute the generation of the metastatic cancer cell to the fusion between a primary cancer cell and a macrophage. However, these theories have not addressed several issues, such as dormancy and stem cell-like self-renewal, of the metastatic cancer cell. On the other hand, recent studies have found that, like T- and B-/plasma cells, macrophages can also be categorized into naïve, effector, and memory/trained macrophages. As a memory/trained macrophage can enter dormancy/quiescence, be awakened from the dormancy/quiescence by acquainted primers, and re-populate via stem cell-like self-renewal, we, therefore, further specify that the macrophage fusing with the cancer cell and contributing to metastasis, belongs with the memory/trained macrophage, not other subtypes of macrophages. The current theory can explain many puzzling clinical features of cancer, including the paradoxal effects (recurrence vs. regression) of microbes on tumors, "spontaneous" and Coley's toxin-induced tumor regression, anticancer activities of β-blockers and anti-inflammatory/anti-immune/antibiotic drugs, oncotaxis, surgery- and trauma-promoted metastasis, and impact of microbiota on tumors. Potential therapeutic strategies, such as Coley's toxin-like preparations, are proposed. This is the last article of our trilogy on carcinogenesis theories.

Evaluation of the effects of postoperative pleural empyema on survival rates of patients after pneumonectomy due to non-small cell lung cancer

Introduction

Postpneumonectomy empyema (PPE) is a severe and often fatal complication of pneumonectomy, but some benefits of PPE were reported in patients who underwent either lobe or an entire lung resection due to lung cancer.

Aim

To compare the survival outcomes of patients with non-small-cell lung carcinoma (NSCLC), who developed PPE after pneumonectomy with uneventful recoveries available in our center's database.

Material and methods

Outcomes of 928 pneumonectomies performed due to NSCLC between 1995 and 2009 were evaluated. The selection of the control group took into account the requirements for propensity score matching in terms of follow-up period, age, sex, tumor histopathology, TNM classification and the side of surgery.

Results

Thirty-two patients with a PPE syndrome and 96 patients without complications after pneumonectomy were included. The estimated 5- and 10-year survival rates were 71% and 59%, respectively. The average and median survival was almost two- and three-fold longer compared to the group with uneventful recoveries. A 2-fold lower cancer-related mortality rate and a 1.5-fold higher cancer-unrelated mortality rate were noted in the PPE group as opposed to the group without complications. Having recovered from PPE, the patients had their risk of death reduced by 2.5-fold and 3.5-fold due to all causes and cancer, respectively.

Conclusions

Pleural empyema in NSCLC patients who underwent pneumonectomy seems to improve the survival outcomes compared to patients with uneventful recoveries.

The 1926 novel, "One, no one, one hundred thousand", metaphorizes the potential danger when the immune system is exposed to a repetitive antigen stimulation

In the worldwide scenario of infection prevention and control, the vaccine strategies are destined to increase rapidly. The availability of numerous vaccination options allows you to plan individually on how to boost your immune system. The immune system is a highly plastic cognitive dynamic network and performs its function by recognition of the uniqueness of the organism defined as self. The identification and attack of non-self antigens contribute to improving the strategies of self/non-self discrimination. However, repetitive antigen stimulation of the immune system may lead to several outcomes reassumed in three principal risks: (i) loss of the unique self codification (one), (ii) loss of own identifying (no one), and (iii) the increase of idiotype/anti-idiotype entities (one hundred thousand). Controlled production of idiotype/anti-idiotype antibodies protects against autoimmune diseases and immunodeficiency. The title of the famous novel by Nobel Prize for Literature winner Luigi Pirandello, "One, no one, one hundred thousand", recaps the three risks and the protagonist's journey exploring the complexities of personal identity, and warns to preserve the uniqueness of the organism. Taking inspiration from this metaphor, the authors propose to monitor antibody idiotype response for personalizing vaccine plans with the aim of preserving the uniqueness of the immune system and assuring safe protection.

Alveolar Macrophages: Adaptation to Their Anatomic Niche during and after Inflammation

At the early stages of life development, alveoli are colonized by embryonic macrophages, which become resident alveolar macrophages (ResAM) and self-sustain by local division. Genetic and epigenetic signatures and, to some extent, the functions of ResAM are dictated by the lung microenvironment, which uses cytokines, ligand-receptor interactions, and stroma cells to orchestrate lung homeostasis. In resting conditions, the lung microenvironment induces in ResAM a tolerogenic programming that prevents unnecessary and potentially harmful inflammation responses to the foreign bodies, which continuously challenge the airways. Throughout life, any episode of acute inflammation, pneumonia being likely the most frequent cause, depletes the pool of ResAM, leaving space for the recruitment of inflammatory monocytes that locally develop in monocyte-derived alveolar macrophages (InfAM). During lung infection, the local microenvironment induces a temporary inflammatory signature to the recruited InfAM to handle the tissue injury and eliminate the pathogens. After a few days, the recruited InfAM, which locally self-sustain and develop as new ResAM, gain profibrotic functions required for tissue healing. After the complete resolution of the infectious episode, the functional programming of both embryonic and monocyte-derived ResAM remains altered for months and possibly for the entire life. Adult lungs thus contain a wide diversity of ResAM since every infection brings new waves of InfAM which fill the room left open by the inflammatory process. The memory of these innate cells called trained immunity constitutes an immunologic scar left by inflammation, notably pneumonia. This memory of ResAM has advantages and drawbacks. In some cases, lung-trained immunity offers better defense capacities against autoimmune disorders and the long-term risk of infection. At the opposite, it can perpetuate a harmful process and lead to a pathological state, as is the case among critically ill patients who have immune paralysis and are highly susceptible to hospital-acquired pneumonia and acute respiratory distress syndrome. The progress in understanding the kinetics of response of alveolar macrophages (AM) to lung inflammation is paving the way to new treatments of pneumonia and lung inflammatory process.

Narrative review of theoretical considerations regarding HITHOC between past and future

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Smallpox and BCG vaccination in childhood and cutaneous malignant melanoma in Danish adults followed from 18 to 49 years

BACKGROUND

Early smallpox and Bacillus Calmette-Guérin (BCG) vaccinations have been associated with reduced risk of cutaneous malignant melanoma (CMM). We assessed the association between pre-school smallpox vaccination and early-school BCG vaccination and CMM in a young Danish population.

METHODS

We conducted a register-based case-cohort study of individuals growing up during the phase-out period of smallpox and BCG vaccination in Denmark (born 1965-1976) utilising the decrease in vaccination during this period. Information on childhood vaccinations and potential confounders from Copenhagen school health records were linked with nationwide registers on cancer (CMM diagnoses), migrations and deaths by personal identification numbers.

RESULTS

The individuals were followed from age 18 until 31/12/2014 (maximum age at end of follow-up, 49 years). 188 cases of CMM occurred in the background population of 46,239 individuals; 172 CMM cases (91%) had full information and were analysed. The adjusted hazard ratio (HR) for CMM by BCG and/or smallpox vaccination compared with neither vaccine was 1.29 (95% confidence interval (CI) 0.72-2.31). For smallpox vaccination only, HR = 1.23 (95% CI 0.53-2.86) for BCG vaccination only, HR = 1.13 (95% CI 0.61-2.09) and for both smallpox and BCG vaccination, HR = 1.75 (95% CI 0.87-3.48) compared with none of these. Vaccination below the age of one year gave similar results.

CONCLUSIONS

We found no strong beneficial effect of smallpox and BCG vaccination against CMM among young adult Danes and with broad confidence intervals our data alone could be compatible with both modest preventive effects, no effects, and modest harmful effects. Our estimates do not contradict a potential modest beneficial effect of neonatal vaccination.

Insulin Signaling and Insulin Resistance Facilitate Trained Immunity in Macrophages Through Metabolic and Epigenetic Changes

Adaptation of the innate immune system has been recently acknowledged, explaining sustained changes of innate immune responses. Such adaptation is termed trained immunity. Trained immunity is initiated by extracellular signals that trigger a cascade of events affecting cell metabolism and mediating chromatin changes on genes that control innate immune responses. Factors demonstrated to facilitate trained immunity are pathogenic signals (fungi, bacteria, viruses) as well non-pathogenic signals such as insulin, cytokines, adipokines or hormones. These signals initiate intracellular signaling cascades that include AKT kinases and mTOR as well as histone methylases and demethylases, resulting in metabolic changes and histone modifications. In the context of insulin resistance, AKT signaling is affected resulting in sustained activation of mTORC1 and enhanced glycolysis. In macrophages elevated glycolysis readily impacts responses to pathogens (bacteria, fungi) or danger signals (TLR-driven signals of tissue damage), partly explaining insulin resistance-related pathologies. Thus, macrophages lacking insulin signaling exhibit reduced responses to pathogens and altered metabolism, suggesting that insulin resistance is a state of trained immunity. Evidence from Insulin Receptor as well as IGF1Receptor deficient macrophages support the contribution of insulin signaling in macrophage responses. In addition, clinical evidence highlights altered macrophage responses to pathogens or metabolic products in patients with systemic insulin resistance, being in concert with cell culture and animal model studies. Herein, we review the current knowledge that supports the impact of insulin signaling and other insulin resistance related signals as modulators of trained immunity.

[Vaccines for the treatment of non-small cell lung cancer]

Antigen-specific immunotherapy also known as cancer vaccination offers a novel approach for the treatment of non-small cell lung cancer patients. It relies on specific priming of the immune system in order to provoke or increase adaptive antitumor immune response against the vaccine component. Several molecules have been developed in lung cancer, based on whole-tumor cells, dendritic cells, peptides, recombinant proteins, or viral vectors. The aim of this review is to describe the mechanism of action of these vaccines and the results of the main clinical studies.

Long-term reprogramming of the innate immune system

During the last few years, a growing body of evidence has shown that immunological memory is not an exclusive trait of lymphocytes, as many inflammatory insults can alter the functionality and the responsiveness of the innate immune system in the long term. Innate immune cells, such as monocytes, macrophages, dendritic cells, and NK cells can be influenced by the encounters with inflammatory stimuli, undergoing functional reprogramming and developing changed responses to subsequent chellenges. The long-term reprogramming depends on the rewiring of cell metabolism and epigenetic processes, and they stay at the basis of induction of both innate immune memory (also termed trained immunity) and innate immune tolerance. Here, we review the central role that the effects of this long-term reprogramming of innate immune cells plays in a number of clinically relevant conditions such as vaccination, atherosclerosis, sepsis, and cancer.

Yellow fever vaccine 17D administered to healthy women aged between 40 and 54 years halves breast cancer risk: an observational study

Transcripts of human endogenous retrovirus K are expressed in most breast cancers (BCs). Yellow fever vaccine 17D (YFV) expresses a protein with a closely homologous epitope. Cross-reactive immunity could hypothetically inhibit BC growth at least in women aged around 50 years at diagnosis, in whom the prognosis of BC was found to be better than that in women younger or older. A cohort of 12 804 women who received YFV in the Veneto Region, Italy, was divided into two subcohorts according to age at vaccination and followed up through the Veneto Tumor Registry. The time since vaccination until cancer incidence was categorized (≤1.9; 2-3.9; 4-5.9; 6-7.9; 8-10.9; ≥11 years) and, using the lowest class as a reference, the incidence rate ratio for BC with a 95% confidence interval and P-value was estimated by Poisson regression in each time since vaccination class, adjusting for age and calendar period. In 3140 women vaccinated at 40-54 years of age, YFV administration resulted in a protective effect of long duration slowly fading over time with a U-shaped pattern of response. Overall, BC risk was reduced by about 50% (incidence rate ratio=0.46; 95% confidence interval=0.26-0.83; P=0.009) 2 years after vaccination. Cross-reactive antigens could not be the mechanism because no protection was observed in women vaccinated before 40 or after 54 years of age. BC cells in a microscopic stage of disease can be destroyed or severely damaged by YFV if BC is not very aggressive. To prove that treatment is truly effective, a placebo-controlled double-blind trial should be conducted.

Hypothesis: stimulation of trained immunity as adjunctive immunotherapy in cancer

Cancer immunotherapy has steadily progressed during the past decades, with checkpoint inhibitor therapy becoming the latest and one of the most promising treatments. Despite the progress, most of the patients do not respond or develop resistance, and novel additional approaches are needed to improve the clinical effectiveness of immunotherapy. Trained immunity (TI) has been described recently as a process of epigenetic and metabolic reprogramming that induces a long-term enhanced function of innate immune cells. TI is considered to have beneficial effects in improving host response to infections and vaccination, and increasing evidence suggests that TI-mediated mechanisms also have useful and potent antitumor effects. We hypothesized that novel and more effective approaches for immunotherapy in cancer may involve induction of TI, alone or in combination with current immunotherapies.

Nivolumab, anti-programmed death-1 (PD-1) monoclonal antibody immunotherapy: Role in advanced cancers

The development of immune checkpoint inhibitors has altered the landscape of treatment of advanced cancers. These drugs are well tolerated and have shown clinical activity against a wide variety of solid tumors and hematological malignancies. The durability of response is particularly impressive when compared to other forms of systemic therapy. Nivolumab (Opdivo) is an IgG4 antibody that causes immune checkpoint blockade by diminishing inhibitory signaling through the programmed death receptor-1 pathway. It is approved for treatment of recurrent non-small cell lung cancer, melanoma, and renal cell carcinoma. Efforts to identify biomarkers of response to nivolumab are ongoing. Clinical trials are also being conducted to determine the benefits of combining nivolumab with other forms of treatment including chemotherapy, molecular-targeted therapy, radiation therapy, and other forms of immune therapy. This review outlines the clinical trials that have led to the emergence of nivolumab as a treatment option for patients with advanced cancers.

The Unspecific Side of Acquired Immunity Against Infectious Disease: Causes and Consequences

Acquired immunity against infectious disease (AIID) has long been considered as strictly dependent on the B and T lymphocytes of the adaptive immune system. Consequently, AIID has been viewed as highly specific to the antigens expressed by pathogens. However, a growing body of data motivates revision of this central paradigm of immunology. Unrelated past infection, vaccination, and chronic infection have been found to induce cross-protection against numerous pathogens. These observations can be partially explained by the poly-specificity of antigenic T and B receptors, the Mackaness effect and trained immunity. In addition, numerous studies highlight the importance of microbiota composition on resistance to infectious disease via direct competition or modulation of the immune response. All of these data support the idea that a non-negligible part of AIID in nature can be nonspecific to the pathogens encountered and even of the antigens expressed by pathogens. As this protection may be dependent on the private T and B repertoires produced by the random rearrangement of genes, past immune history, chronic infection, and microbiota composition, it is largely unpredictable at the individual level. However, we can reasonably expect that a better understanding of the underlying mechanisms will allow us to statistically predict cross-protection at the population level. From an evolutionary perspective, selection of immune mechanisms allowing for partially nonspecific AIID would appear to be advantageous against highly polymorphic and rapidly evolving pathogens. This new emerging paradigm may have several important consequences on our understanding of individual infectious disease susceptibility and our conception of tolerance, vaccination and therapeutic strategies against infection and cancer. It also underscores the importance of viewing the microbiota and persisting infectious agents as integral parts of the immune system.