Wolf H. Fridman

The immune contexture in human tumours: impact on clinical outcome

Tumours grow within an intricate network of epithelial cells, vascular and lymphatic vessels, cytokines and chemokines, and infiltrating immune cells. Different types of infiltrating immune cells have different effects on tumour progression, which can vary according to cancer type. In this Opinion article we discuss how the context-specific nature of infiltrating immune cells can affect the prognosis of patients.

The same tyrosine-based inhibition motif, in the intra-cytoplasmic domain of FcγRIIB, regulates negatively BCR-, TCR-, and FcR-dependent cell activation

The cell-triggering properties of BCR, TCR and FcR depend on structurally related immunoreceptor tyrosine-based activation motifs (ITAMs). Fc gamma RIIB have no ITAM and do not trigger cell activation. When coaggregated to BCR, they inhibit B cell activation. We show here that, when coaggregated to these receptors, Fc gamma RIIB inhibit Fc epsilon RI-, Fc gamma RIIA-, and TCR-dependent cell activation. Inhibition also affected cell activation by single ITAMs, in isolated FcR or TCR subunits. The same tyrosine-based inhibitory motif (ITIM), which is highly conserved in murine and human Fc gamma RIIB and that was previously shown to inhibit BCR-dependent B cell activation, was required to regulate TCR- and FcR-dependent cell activation. Our findings endow Fc gamma RIIB, and thus IgG antibodies, with general immunoregulatory properties susceptible to act on all ITAM-containing receptors.

In Situ Cytotoxic and Memory T Cells Predict Outcome in Patients With Early-Stage Colorectal Cancer

PURPOSE Many patients who present with early-stage colorectal cancer (International Union Against Cancer TNM stages I and II) are nevertheless at high risk of relapse. We hypothesized that intratumoral immune reaction could influence their prognosis. PATIENTS AND METHODS The intratumoral immune reaction was investigated in 29 tumors by large-scale real-time polymerase chain reaction. Cytotoxic (CD8) and memory (CD45RO) T cells were quantified by immunohistochemical analyses of tissue microarrays from the center (CT) and the invasive margin (IM) of the 602 tumors from two independent cohorts. The results were correlated with tumor recurrence and patient survival. RESULTS Patients with a strong infiltration of CD45RO(+) cells in the tumor exhibited an increased expression of T-helper 1 and cytotoxicity-related genes. Densities of CD45RO(+) and CD8(+) cells in tumor regions (CT/IM) classified the patients into four distinct prognostic groups based on the presence of high density of each marker in each tumor region. The four groups were associated with dramatic differences in disease-free, disease-specific, and overall survival (all P < .0001). Five years after diagnosis, only 4.8% (95% CI, 0.6% to 8.8%) of patients with high densities of CD8(+) plus CD45RO(+) cells had tumor recurrence, and 86.2% (CI, 79.4% to 93.6%) survived. In contrast, the tumor recurred in 75% (95% CI, 17% to 92.5%) of patients with low densities of these cells, and only 27.5% (95% CI, 10.5% to 72%) survived (all P < .0001). Multivariate analyses showed that the immune criteria had independent effects on the rates of complete remission and survival. CONCLUSION The combined analysis of CD8(+) plus CD45RO(+) cells in specific tumor regions could provide a useful criterion for the prediction of tumor recurrence and survival in patients with early-stage colorectal cancer.

Prognostic Value of Tumor-Infiltrating CD4+ T-Cell Subpopulations in Head and Neck Cancers

Purpose: CD4+ T cells play a central role in initiating and maintaining anticancer immune responses. However, regulatory CD4+CD25+ T cells which express Foxp3 have also been shown to inhibit antitumor effector T cells. In view of these heterogeneous CD4+ T-cell populations, this study was designed to determine the prognostic value of various tumor-infiltrating CD4+ T-cell populations in head and neck squamous cell carcinoma. Experimental Design: Eighty-four newly diagnosed untreated patients with histologically proven primary head and neck squamous cell carcinoma were included in this study. Double or triple immunofluorescence staining was done to assess and quantify the activated CD4+CD69+ T cells, regulatory CD4+Foxp3+ T cells, and mixed CD4+CD25+ T cells comprising both activated and regulatory T cells. Results: On univariate analysis, high levels of tumor-infiltrating CD4+CD69+ T cells were correlated with both better locoregional control (P = 0.01) and longer survival (P = 0.01). Infiltration by regulatory Foxp3+CD4+ T cells was positively associated with a better locoregional control of the tumor. Multivariate analysis showed that the only significant prognostic factors related to locoregional control were T stage (P = 0.02) and CD4+Foxp3+ T-cell infiltration of the tumor (P = 0.02). In the Cox multivariate analysis, only two variables influenced overall survival probability: T stage (P = 0.036) and CD4+CD69+ T-cell infiltration (P = 0.017). Conclusion: This study shows that tumor-infiltrating activated CD4+CD69+ T cells are associated with a good prognosis in head and neck squamous cell carcinoma. In addition, regulatory Foxp3+CD4+ T cells are positively correlated with locoregional control may be through down-regulation of harmful inflammatory reaction, which could favor tumor progression.

Mutations in complement C3 predispose to development of atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome (aHUS) is a disease of complement dysregulation. In approximately 50% of patients, mutations have been described in the genes encoding the complement regulators factor H, MCP, and factor I or the activator factor B. We report here mutations in the central component of the complement cascade, C3, in association with aHUS. We describe 9 novel C3 mutations in 14 aHUS patients with a persistently low serum C3 level. We have demonstrated that 5 of these mutations are gain-of-function and 2 are inactivating. This establishes C3 as a susceptibility factor for aHUS.

Heterozygous and Homozygous Factor H Deficiencies Associated with Hemolytic Uremic Syndrome or Membranoproliferative Glomerulonephritis: Report and Genetic Analysis of 16 Cases

Factor H (FH) is the major regulatory protein of the complement alternative pathway, with a structure consisting of a tandem array of 20 homologous units, called short consensus repeats (SCR). Reported are 16 FH-deficient patients. Among six patients with homozygous deficiency, four presented with membranoproliferative glomerulonephritis, and two with atypical hemolytic uremic syndrome (HUS). The ten other patients had heterozygous FH deficiency and developed atypical HUS. HUS onset occurred from birth to midadulthood, and disease progression was variable. Four children with homozygous or heterozygous FH deficiency and HUS underwent renal transplantation, which was successful in three but failed as a result of recurrence of HUS in one patient. All but one patient exhibited alternative pathway-mediated complement consumption, with no detectable FH antigenic levels or with 50% immunochemical or functional FH levels in the case of complete or partial deficiency, respectively. The molecular mechanisms of the deficiency were documented in all cases by exon-specific sequencing analysis. These mechanisms included nucleotide substitutions, insertion, or deletion located in SCR 2, 7, 11, 13, 15, and 20, leading to an amino acid substitution or to a stop codon. This report emphasizes the variability in the clinical progression of kidney diseases associated with FH deficiencies. Genetic analysis reveals the molecular abnormalities associated with FH deficiencies to be polymorphous.

PD-1–Expressing Tumor-Infiltrating T Cells Are a Favorable Prognostic Biomarker in HPV-Associated Head and Neck Cancer

Head and neck cancers positive for human papillomavirus (HPV) have a more favorable clinical outcome than HPV-negative cancers, but it is unknown why this is the case. We hypothesized that prognosis was affected by intrinsic features of HPV-infected tumor cells or differences in host immune response. In this study, we focused on a comparison of regulatory Foxp3(+) T cells and programmed death-1 (PD-1)(+) T cells in the microenvironment of tumors that were positive or negative for HPV, in two groups that were matched for various clinical and biologic parameters. HPV-positive head and neck cancers were more heavily infiltrated by regulatory T cells and PD-1(+) T cells and the levels of PD-1(+) cells were positively correlated with a favorable clinical outcome. In explaining this paradoxical result, we showed that these PD-1(+) T cells expressed activation markers and were functional after blockade of the PD-1-PD-L1 axis in vitro. Approximately 50% of PD-1(+) tumor-infiltrating T cells lacked Tim-3 expression and may indeed represent activated T cells. In mice, administration of a cancer vaccine increased PD-1 on T cells with concomitant tumor regression. In this setting, PD-1 blockade synergized with vaccine in eliciting antitumor efficacy. Our findings prompt a need to revisit the significance of PD-1-infiltrating T cells in cancer, where we suggest that PD-1 detection may reflect a previous immune response against tumors that might be reactivated by PD-1/PD-L1 blockade.

Prognostic and Predictive Impact of Intra- and Peritumoral Immune Infiltrates

Leukocyte infiltrates into or around tumor cell nests are found in the context of protumorigenic inflammation and anticancer immunosurveillance. Hence, the detailed composition, density, architecture, and function of leukocyte infiltrates must be analyzed to understand their prognostic impact. The ectopic presence within tumors of high endothelial venule cells, which are normally characteristic for secondary lymphoid organs, correlates with a more pronounced infiltration by T lymphocytes and has a positive predictive impact on local advanced breast cancer treated with neoadjuvant chemotherapy. Recent progress in the field indicates that immune infiltrates of the primary tumors, as well as of metastases, are not only independent prognostic biomarkers but can also constitute predictive factors, suggesting that the pretherapeutic immune response can determine the efficacy of conventional chemotherapies. Moreover, accumulating evidence indicates that chemotherapy can stimulate anticancer immune responses coupled with an increased intratumoral lymphoid infiltration, which correlates with tumor mass reduction and patient survival. Improved methods for the automation of immunohistochemistry and digitalized image analyses will pave the way to an improved understanding of the complex interplay between cancer parenchyma, stroma, and immune effectors, as well as to the routine evaluation of immune-related parameters to the clinical management of cancer patients.

Differential modulation of stimulatory and inhibitory Fc gamma receptors on human monocytes by Th1 and Th2 cytokines.

Immune complex-mediated inflammatory responses are initiated by FcγR on phagocytes. We report in this study that an inhibitory receptor, FcγRIIb2, is expressed on circulating human monocytes, and when co-cross-linked with stimulatory FcγR it down-regulates effector function. FcγRIIb2 expression is increased by IL-4 and decreased by IFN-γ, in contrast to the activating receptor, FcγRIIa, which is increased by IFN-γ and decreased by IL-4. Thus, Th1 and Th2 cytokines differentially regulate the opposing FcγR systems, altering the balance of activating and inhibiting FcγR. The detection and cytokine modulation of FcγRIIb2 in human myeloid cells provide evidence of a negative regulator of immune complex-mediated responses in human phagocytes and offer a new approach to limit Ab-triggered inflammation in autoimmune disease.

Genetic and Functional Analyses of Membrane Cofactor Protein (CD46) Mutations in Atypical Hemolytic Uremic Syndrome

Hemolytic uremic syndrome (HUS) is characterized by the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. The non-Shiga toxin-associated HUS (atypical HUS [aHUS]) has been shown to be a disease of complement dysregulation. Mutations in the plasma complement regulators factor H and factor I and the widely expressed membrane cofactor protein (MCP; CD46) have been described recently. This study looked for MCP mutations in a panel of 120 patients with aHUS. In this cohort, approximately 10% of patients with aHUS (11 patients; nine pedigrees) have mutations in MCP. The onset typically was in early childhood. Unlike patients with factor I or factor H mutations, most of the patients do not develop end-stage renal failure after aHUS. The majority of patients have a mutation that causes reduced MCP surface expression. A small proportion expressed normal levels of a dysfunctional protein. As in other studies, incomplete penetrance is shown, suggesting that MCP is a predisposing factor rather than a direct causal factor. The low level of recurrence of aHUS in transplantation in patients with MCP mutations is confirmed, and the first MCP null individuals are described. This study confirms the association between MCP deficiency and aHUS and further establishes that a deficiency in complement regulation, specifically cofactor activity, predisposes to severe thrombotic microangiopathy in the renal vasculature.