Presence of an eosinophilic infiltrate in cervical squamous carcinoma results from a type 2 immune response

Type 1 and type 2 cytokine-mediated immune orchestration in the tumour microenvironment and their therapeutic potential

Cancer remains the second leading cause of death worldwide despite modern breakthroughs in medicine, and novel treatments are urgently needed. The revolutionary success of immune checkpoint inhibitors in the past decade serves as proof of concept that the immune system can be effectively harnessed to treat cancer. Cytokines are small signalling proteins with critical roles in orchestrating the immune response and have become an attractive target for immunotherapy. Type 1 immune cytokines, including interferon γ (IFNγ), interleukin-12 (IL-12), and tumour necrosis factor α (TNFα), have been shown to have largely tumour suppressive roles in part through orchestrating anti-tumour immune responses mediated by natural killer (NK) cells, CD8⁺ T cells and T helper 1 (Th1) cells. Conversely, type 2 immunity involving group 2 innate lymphoid cells (ILC2s) and Th2 cells are involved in tissue regeneration and wound repair and are traditionally thought to have pro-tumoural effects. However, it is found that the classical type 2 immune cytokines IL-4, IL-5, IL-9, and IL-13 may have conflicting roles in cancer. Similarly, type 2 immunity-related cytokines IL-25 and IL-33 with recently characterised roles in cancer may either promote or suppress tumorigenesis in a context-dependent manner. Furthermore, type 1 cytokines IFNγ and TNFα have also been found to have pro-tumoural effects under certain circumstances, further complicating the overall picture. Therefore, the dichotomy of type 1 and type 2 cytokines inhibiting and promoting tumours respectively is not concrete, and attempts of utilising these for cancer immunotherapy must take into account all available evidence. This review provides an overview summarising the current understanding of type 1 and type 2 cytokines in tumour immunity and discusses the prospects of harnessing these for immunotherapy in light of previous and ongoing clinical trials.

Allergies: diseases closely related to cancer

Allergies are hypersensitivity reactions that occur through specific type Th2 immunological mechanisms characterized by different soluble mediators, as well as specific cells of the immune system. In recent decades, evidence has emerged relating this disease with cancer development. However, most of the results of epidemiology studies have been controversial and contradictory. There are mainly two trends. While the first indicates that allergies can reduce the risk of cancer, the other indicates that they may increase this risk. The first trend can be explained by the immunosurveillance hypothesis, which states that the increased immune surveillance after the immune hyper-responsiveness can inhibit or exert a protective effect against the development of cancer. Similarly, the prophylaxis hypothesis suggests that the physical effects of allergy symptoms can prevent cancer by removing potential carcinogens. In contrast, the opposing hypothesis propose that there is a deviation of the immune response toward Th2, which favors the development of cancer, or that the process of chronic inflammation favors the generation of mutations, and therefore the development of cancer. With the purpose of understanding more about these two hypotheses, the main soluble and cellular factors of allergic diseases that could be playing a key role in the development or inhibition of cancer were considered in this review.

Tumor eosinophil infiltration and improved survival of colorectal cancer patients: Iowa Women's Health Study

The role of the innate immune response in colorectal cancer is understudied. We examined the survival of colorectal cancer patients in relation to eosinophils, innate immune cells, infiltrating the tumor. Tissue microarrays were constructed from paraffin-embedded tumor tissues collected between 1986 and 2002 from 441 post-menopausal women diagnosed with colorectal cancer in the Iowa Women's Health Study. Tissue microarrays were stained with an eosinophil peroxidase antibody. Eosinophils in epithelial and stromal tissues within the tumor (called epithelial and stromal eosinophils, hereafter) were counted and scored into three and four categories, respectively. In addition, the degree of eosinophil degranulation (across epithelial and stromal tissues combined) was quantified and similarly categorized. We used Cox regression to estimate the hazard ratios and 95% confidence interval for all-cause and colorectal cancer death during 5-year follow-up after diagnosis and during follow-up through 2011 ('total follow-up'). The hazard ratios associated with eosinophil scores were adjusted for age of diagnosis, SEER (Surveillance, Epidemiology, and End Results) stage, tumor grade, body mass, and smoking history. High tumor stromal eosinophil score was inversely correlated with age and stage, and was associated with a decreased risk for all-cause and colorectal cancer death: hazard ratios (95% confidence intervals) were 0.61 (0.36-1.02; P-trend=0.02) and 0.48 (0.24-0.93; P-trend=0.01), respectively, during the 5-year follow-up for the highest vs lowest category. The inverse associations also existed for total follow-up for all-cause and colorectal cancer death for the highest vs lowest stromal eosinophil score: hazard ratios (95% confidence intervals) were 0.72 (0.48-1.08; P-trend=0.04) and 0.61 (0.34-1.12; P-trend=0.04), respectively. Further adjustment for treatment, comorbidities, additional lifestyle factors, tumor location, or molecular markers did not markedly change the associations, while adjustment for cytotoxic T cells slightly attenuated all associations. The infiltration of tumors with eosinophils, especially in stromal tissue, may be an important prognostic factor in colorectal cancer.

Functional tumor infiltrating TH1 and TH2 effectors in large early-stage cervical cancer are suppressed by regulatory T cells

OBJECTIVE

Analysis of tumor-infiltrating lymphocytes (TILs) is one of the cornerstones for the understanding of immune responses prevailing in the tumor microenvironment. We studied TILs from squamous cell carcinoma of the cervix ex vivo without proliferating them in vitro before analysis.

METHODS

Whereas TILs were magnetic activated cell separation enriched and flow sorted into CD4 CD25 (regulatory T cells [Tregs]), CD4 CD25 (effector T cells [Teffs]) were directly purified by flow cytometry, and both these subsets were characterized phenotypically and functionally. Tissue sections were probed for interleukin 4 (IL-4) and interferon γ.

RESULTS

Effector T cells constitutively expressed both interferon γ and IL-4 prototypical cytokines of TH1 and TH2, respectively, and were able to proliferate and secrete higher quantities of both cytokines in response to anti-CD3/anti-CD28 and autologous tumor lysates. Only 53% of cervical cancer Tregs were FOXP3, elaborated transforming growth factor β1, and IL-10 and were able to inhibit both T helper subsets.

CONCLUSIONS

Intratumoral Teffs represented functionally active subsets of both TH1 and TH2 that were not anergic but were suppressed by multiple Treg subsets, which comprised FOXP3 + Tregs and Tregs secreting transforming growth factor β1 and IL-10. These results imply that the microenvironment of cervical carcinomas harbored both TH1 and TH2 subsets of CD4 Teffs that were functionally active but were perhaps unable to perform because of the overpowering effect of Tregs.

Therapeutic strategies for harnessing human eosinophils in allergic inflammation, hypereosinophilic disorders, and cancer

The eosinophil is a multifunctional granulocyte best known for providing host defense against parasites. Paradoxically, eosinophils are also implicated in the pathogenesis of allergic inflammation, asthma, and hypereosinophilic syndromes. Emerging evidence also supports the potential for harnessing the cytotoxic power of eosinophils and redirecting it to kill solid tumors. Central to eosinophil physiology is interleukin-5 (IL-5) and its receptor (IL-5R) which is composed of a ligand-specific alpha chain (IL-5Rα) and the common beta chain (βc). Eosinophil activation can lead to their degranulation, resulting in rapid release of an arsenal of tissue-destructive proinflammatory mediators and cytotoxic proteins that can be both beneficial and detrimental to the host. This review discusses eosinophil immunobiology and therapeutic strategies for targeting of IL-5 and IL-5R, as well as the potential for harnessing eosinophil cytotoxicity as a tumoricide.

Expression of interleukin-5 and tumor necrosis factor alpha in cervical carcinoma

Interleukin-5 (IL-5) levels were significantly higher in vaginal washing fluids from patients with cervical carcinoma than in those from patients with carcinoma in situ and controls. Tumor necrosis factor alpha levels did not differ among the three groups. Detection of IL-5 in cervical secretions may be a useful marker for evaluating aggressive local immune response in cervical carcinoma.

Eosinophil-induced prognosis improvement of solid tumors could be enabled by their vesicle-mediated barrier permeability induction

Eosinophils are multifunctional cells, which contain and produce many biologically active substances. Generally, eosinophilia is associated with parasitic infections or allergic disorders, while according to recent studies eosinophil infiltration is also present in target tissues of both physiological and pathological processes, such as angiogenesis, embryogenesis, immune regulation, different infections or neoplasies, leading to tissue damage or remodeling. Reflecting on prognosis improvement in the case of solid tumors after eosinophilic infiltration of their capsules, it could be hypothesized that eosinophils are not tumoricidal per se; rather they can perforate such barriers through their vesicles' content, whereas the tumoricidal cytokines such as interleukin 4 (IL-4) fulfill the tumoral necrosis. This scenario can be supported by the fact that IL-4 originated from macrophages and lymphocytes fails to mediate tumor necrosis in vitro conditions in absence of eosinophils. In addition, the requirement of eosinophil-mediated increasing permeability among diverse biologic barriers and tissues may explain the eosinophils' introduction in capsules of cysts, mucosal membrane of respiratory and gastroenteric systems, hemato-encephalic barrier, in embryos, as well as in bacterial and parasitic membranes. Thus, in some situations rather than being multifunctional effectors per se, eosinophils, due to induction of target barrier dysfunction, may assure the host-required action, mediated by various kinds of leucocytes and their biologic effectors. Consequently, a better understanding of physiology and patho-physiology of this enigmatic cell will lead to new clinical strategies.

Significance of neo-angiogenesis and immuno-surveillance cells in squamous cell carcinoma of the tongue

Background

Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological behaviour of tumours. Nevertheless, their function in tissues is uncertain. Mast cells are involved in homeostatic regulation of blood vessels as well as host defence. In some malignancies, high mast cell density has been found to correlate with favourable prognosis. However, others reported unfavourable associations. Tumour associated tissue eosinophilia is a well-known phenomena. It has been associated with good and poor prognosis. However, the role of eosinophils in tumours remains controversial. Therefore, this study was designed to investigate the prognostic value of microvessel, mast cell and eosinophil densities in the context of clinico-pathological parameters and survival in squamous cell carcinoma of the tongue.

Materials and Methods

Anti-CD105 and anti-tryptase monoclonal antibodies were utilized to highlight and count microvessels and mast cells respectively in 81 cases of tongue squamous cell carcinoma. Eosinophils were demonstrated using carbol chromotrope histochemical stain. The densities were counted per mm2 and correlated with patients’ outcome and other clinico-pathological parameters using non-parametric tests and student's t-test. Clinically, the cases were divided into 4 main groups depending on survival time, lymph-node or distant metastasis.

Results

The 5 year survival was significantly lower in patients with a low mast cell density than those with a high density (p=0.006, Kruskal-Wallis test). The survival group-A demonstrated significantly higher mast cell and microvessel numbers than group-D (p=0.007, student's t-test) respectively. Patients with well- differentiated squamous cell carcinoma had significantly higher numbers of mast cells when compared to patients with poorly differentiated squamous cell carcinoma (p<0.05, student's t-test). The lymph node involvement correlation between the survival group-A and survival group-D was also significant (p=0.001, Mann-Whitney U test).

Conclusion

Data from this study indicates that accumulating mast cells in tumours play a part in inhibiting tumour progression and is potentially angiogenic in tumours.

The pathology of cervical tumours

Carcinomas of the cervix may be categorized on morphological grounds into four main groups: squamous carcinomas; adenocarcinomas; neuro-endocrine tumours; and others including adenosquamous carcinomas. Each group contains several morphological subvariants. Invasive squamous carcinomas and adenocarcinomas are preceded by cervical intra-epithelial neoplasia and cervical glandular intra-epithelial neoplasia, respectively. Each is graded into low and high grade. Micro-invasive carcinomas with stromal invasion less than 3mm in depth have a minimal chance of lymph node metastasis. When there is lymph node involvement, the obturator node may be the most common. Presence or absence of lymph node involvement, tumour size and depth of invasion are the important independent histopathological indicators of prognosis. The presence or absence of vascular space invasion is a valuable prognostic indicator. Small cell carcinomas, large cell neuro-endocrine carcinomas and possibly adenoid cystic carcinomas are aggressive. With these exceptions, it is doubtful whether tumour type is of much clinical significance. Tumour grade, as currently assessed, is of no significant value.

Immune response in cervical dysplasia induced by human papillomavirus: the influence of human immunodeficiency virus-1 co-infection - review

Human immunodeficiency virus (HIV-1) has become an important risk factor for human papillomavirus (HPV) infection and the development of HPV associated lesions in the female genital tract. HIV-1 may also increase the oncogenicity of high risk HPV types and the activation of low risk types. The Center for Disease Control and Prevention declared invasive cervical cancer an acquired immunodeficiency virus (AIDS) defining illness in HIV positive women. Furthermore, cervical cancer happens to be the second most common female cancer worldwide. The host's local immune response plays a critical factor in controlling these conditions, as well as in changes in the number of professional antigen-presenting cells, cytokine, and MHC molecules expression. Also, the production of cytokines may determine which arm of the immune response will be stimulated and may influence the magnitude of immune protection. Although there are many studies describing the inflammatory response in HPV infection, few data are available to demonstrate the influence of the HIV infection and several questions regarding the cervical immune response are still unknown. In this review we present a brief account of the current understanding of HIV/HPV co-infection, emphasizing cervical immune response.

Identification and characterisation of a group of cervical carcinoma patients with profound downregulation of intratumoral Type 1 (IFNgamma) and Type 2 (IL-4) cytokine mRNA expression

Type 1 cytokines, such as interferon gamma (IFNgamma) and interleukin-2 (IL-2), increase T cell-mediated immune responses and are considered to be beneficial for antitumour immunity. Type 2 cytokines, such as IL-4, IL-5, and IL-10, inhibit Type 1 responses and promote humoral responses. We have previously reported an association between low intratumoral IFNgamma mRNA levels and poor clinical outcome in patients with invasive cervical carcinoma. In this study, by using quantitative polymerase chain reaction (PCR), we identified a group of cervical carcinoma patients with undetectable intratumoral T cell-derived cytokine mRNAs, as IFNgamma, IL-4 and IL-17 expression could not be detected in 5, 25 and 8 of the 52 biopsies analysed, respectively. Global downregulation of Type 1 and Type 2 cytokines was observed in a subgroup of patients who more frequently presented advanced stage tumours. Biopsies of patients with no IFNgamma gene expression did not appear to be less infiltrated by T cells than control biopsies with measurable IFNgamma gene expression. These results clearly demonstrate that, in some clinical situations, the decrease in intratumoral Type 1 cytokines is not associated with a Type 2 polarisation, but rather reflects global deactivation of T cells at the tumour site. These data provide support for immunotherapy protocols designed to reverse the anergic state of T cells in cancer.

Tumour-associated tissue eosinophilia as a prognostic factor in oral squamous cell carcinomas

AIMS

Tumour-associated tissue eosinophilia has been described in many sites, including head and neck. The mechanism of eosinophil recruitment and its role in tumours has not yet been defined, and its presence has been related to a favourable as well as unfavourable prognosis. The aim of this study was to evaluate the influence of tumour-associated tissue eosinophilia on the prognosis of 125 oral squamous cell carcinoma patients.

METHODS AND RESULTS

The number of eosinophils was obtained by morphometric analysis and ranged from 0 to 392 per mm2. Tumour-associated tissue eosinophilia was classified according to intensity as mild, moderate, or intense and correlated statistically to the intensity of the mononuclear inflammatory infiltrate as well as to the location of the eosinophilic inflammatory infiltrate. The multivariate analysis demonstrated that intense tumour-associated tissue eosinophilia is an independent favourable prognostic factor for oral squamous cell carcinomas.

CONCLUSION

These findings suggest an anti-tumoral role of eosinophils not as yet well understood that should be better investigated.