Clinical Implications of CD8+ T-cell infiltration in frequent and rare cancers

Complement as Prognostic Biomarker and Potential Therapeutic Target in Renal Cell Carcinoma

Preclinical studies demonstrated that complement promotes tumor growth. Therefore, we sought to determine the best target for complement-based therapy among common human malignancies. High expression of 11 complement genes was linked to unfavorable prognosis in renal cell carcinoma. Complement protein expression or deposition was observed mainly in stroma, leukocytes, and tumor vasculature, corresponding to a role of complement in regulating the tumor microenvironment. Complement abundance in tumors correlated with a high nuclear grade. Complement genes clustered within an aggressive inflammatory subtype of renal cancer characterized by poor prognosis, markers of T cell dysfunction, and alternatively activated macrophages. Plasma levels of complement proteins correlated with response to immune checkpoint inhibitors. Corroborating human data, complement deficiencies and blockade reduced tumor growth by enhancing antitumor immunity and seemingly reducing angiogenesis in a mouse model of kidney cancer resistant to PD-1 blockade. Overall, this study implicates complement in the immune landscape of renal cell carcinoma, and notwithstanding cohort size and preclinical model limitations, the data suggest that tumors resistant to immune checkpoint inhibitors might be suitable targets for complement-based therapy.

Hyaluronan in the Tumor Microenvironment

The extracellular matrix is part of the microenvironment and its functions are associated with the physical and chemical properties of the tissue. Among the extracellular components, the glycosaminoglycan hyaluronan is a key component, defining both the physical and biochemical characteristics of the healthy matrices. The hyaluronan metabolism is strictly regulated in physiological conditions, but in the tumoral tissues, its expression, size and binding proteins interaction are dysregulated. Hyaluronan from the tumor microenvironment promotes tumor cell proliferation, invasion, immune evasion, stemness alterations as well as drug resistance. This chapter describes data regarding novel concepts of hyaluronan functions in the tumor. Additionally, we discuss potential clinical applications of targeting HA metabolism in cancer therapy.

Staphylococcus epidermidis role in the skin microenvironment

Wound healing is a complex dynamic physiological process in response to cutaneous destructive stimuli that aims to restore the cutaneous' barrier role. Deciphering the underlying mechanistic details that contribute to wound healing will create novel therapeutic strategies for skin repair. Recently, by using state-of-the-art technologies, it was revealed that the cutaneous microbiota interact with skin immune cells. Strikingly, commensal Staphylococcus epidermidis-induced CD8+ T cells induce re-epithelization of the skin after injury, accelerating wound closure. From a drug development perspective, the microbiota may provide new therapeutic candidate molecules to accelerate skin healing. Here, we summarize and evaluate recent advances in the understanding of the microbiota in the skin microenvironment.

Intratumoral infiltrating lymphocytes correlate with improved survival in colorectal cancer patients: Independent of oncogenetic features

BACKGROUND

The clinical relevance and prognostic value of tumor-infiltrating lymphocytes (TILs) as an interplay between malignant cells and immune function has been known for decades. On contrary, this potential may be different by T lymphocytes subsets endowed with a different function. Colorectal cancer (CRC) is a heterogeneous disease with different suggested prognostic biomarkers. So, this study was conducted to examine the prognostic value of CD8+ TILs on the survival rate of CRC as an independent factor of oncogenetic tumor features.

METHODS

With respect to this, 281 formalin-fixed, paraffin-embedded tissue samples of Iranian CRC patients were evaluated for clinical features including tumor location, tumor stage, differentiation grade, and mucinous characteristics. Then, using the standard immunohistochemical technique, tumor sections were examined, and CD8+ TILs were counted and identified in two regions of the tumor, including intratumoral (ITCIL TILs) and stromal (S TILs). The prognostic value of CD8⁺ TILs was determined by comparing with parameters, such as diagnostic age, tumor stage, adjuvant therapy, microsatellite instability (MSI) status, KRAS and BRAF mutations, family history, and survival.

RESULTS

The presence of intratumoral tumor cell-infiltrating lymphocytes (ITCIL) CD8+ lymphocytes are significantly associated with differentiation (p = 0.004), tumor, node, and metastases (TNM) stage (p = 0.001), and MSI (p = 0.001). Meanwhile, based on the level of stromal infiltrating lymphocytes (SIL) infiltration, analysis of CRC patients was statistically associated with a location (p = 0.002), TNM stage (p < 0.001), metastasis (p < 0.001), and KRAS mutation (p = 0.031). Also, tumors with severe ITCIL CD8+ lymphocytes have a good prognosis compared with tumors with poor or moderate ITCIL CD8+ lymphocytes.

CONCLUSIONS

These results suggest that intratumor cell-infiltrating CD8- T lymphocytes as an independent prognostic factor that have an antitumor activity as judged by their favorable effect on patients' survival and could potentially be exploited in the treatment of CRC.

Antigen-specific T cells fully conserve antitumour function following cryopreservation

Immunotherapies based on the autologous adoptive transfer of ex vivo-manipulated T cells are rapidly evolving for the treatment of both metastatic and primary malignancies. However, extended ex vivo culturing reduces the functionality of isolated T cells. Cryopreservation of rapidly expanded T cells for subsequent use throughout an immunotherapeutic regimen is a highly desirable recourse, thus far encumbered by a lack of studies investigating its effects on effector T-cell functionality. Here we directly compare murine tumour-reactive CD8⁺ T cells cryopreserved during ex vivo expansion to freshly isolated populations. We show that cryopreservation fully conserves the differentiation potential of effector T cells, secretion of pro-inflammatory cytokines, cytotoxic function and does not impair the three-dimensional scanning motility of T cells or their capacity to infiltrate and reject tumours.

The immunological effect of hyaluronan in tumor angiogenesis

The relationship between the immune system and angiogenesis has been described in several contexts, both in physiological and pathological conditions, as pregnancy and cancer. In fact, different types of immune cells, such as myeloid, macrophages and denditric cells, are able to modulate tumor neovascularization. On the other hand, tumor microenvironment also includes extracellular matrix components like hyaluronan, which has a deregulated synthesis in different tumors. Hyaluronan is a glycosaminoglycan, normally present in the extracellular matrix of tissues in continuous remodeling (embryogenesis or wound healing processes) and acts as an important modulator of cell behavior by different mechanisms, including angiogenesis. In this review, we discuss hyaluronan as a modulator of tumor angiogenesis, focusing in intracellular signaling mediated by its receptors expressed on different immune cells. Recent observations suggest that the immune system is an important component in tumoural angiogenesis. Therefore, immune modulation could have an impact in anti-angiogenic therapy as a new therapeutic strategy, which in turn might improve effectiveness of treatment in cancer patients.

Mobilizing and evaluating anticancer T cells: pitfalls and solutions

Immunotherapy is a promising means to fight cancer, prompting a steady increase in clinical trials and correlative laboratory studies in this field. As antitumor T cells play central roles in immunity against malignant diseases, most immunotherapeutic protocols aim to induce and/or strengthen their function. Various treatment strategies have elicited encouraging clinical responses; however, major challenges have been uncovered that should be addressed in order to fully exploit the potential of immunotherapy. Here, we outline pitfalls for the mobilization of antitumor T cells and offer solutions to improve their therapeutic efficacy. We provide a critical perspective on the main methodologies used to characterize T-cell responses to cancer therapies, with a focus on discrepancies between T-cell attributes measured in vitro and protective responses in vivo. This review altogether provides recommendations to optimize the design of future clinical trials and highlights important considerations for the proficient analysis of clinical specimens available for research.