CD4+ and CD8+ T cells have opposing roles in breast cancer progression and outcome

The Cancer Immunoediting concept has provided critical insights suggesting dual functions of immune system during the cancer initiation and development. However, the dynamics and roles of CD4(+) and CD8(+) T cells in the pathogenesis of breast cancer remain unclear. Here we utilized two murine breast cancer models (4T1 and E0771) and demonstrated that both CD4(+) and CD8(+) T cells were increased and involved in immune responses, but with distinct dynamic trends in breast cancer development. In addition to cell number increases, CD4(+) T cells changed their dominant subsets from Th1 in the early stages to Treg and Th17 cells in the late stages of the cancer progression. We also analyzed CD4(+) and CD8(+) T cell infiltration in primary breast cancer tissues from cancer patients. We observed that CD8(+) T cells are the key effector cell population mediating effective anti-tumor immunity resulting in better clinical outcomes. In contrast, intra-tumoral CD4(+) T cells have negative prognostic effects on breast cancer patient outcomes. These studies indicate that CD4(+) and CD8(+) T cells have opposing roles in breast cancer progression and outcomes, which provides new insights relevant for the development of effective cancer immunotherapeutic approaches

Do salivary bypass tubes lower the incidence of pharyngocutaneous fistula following total laryngectomy? A retrospective analysis of predictive factors using multivariate analysis

Salivary bypass tubes (SBT) are increasingly used to prevent pharyngocutaneous fistula (PCF) following laryngectomy and pharyngolaryngectomy. There is minimal evidence as to their efficacy and literature is limited. The aim of the study was to determine if SBT prevent PCF. The study was a multicentre retrospective case control series (level of evidence 3b). Patients who underwent laryngectomy or pharyngolaryngectomy for cancer or following cancer treatment between 2011 and 2014 were included in the study. The primary outcome was development of a PCF. Other variables recorded were age, sex, prior radiotherapy or chemoradiotherapy, prior tracheostomy, type of procedure, concurrent neck dissection, use of flap reconstruction, use of prophylactic antibiotics, the suture material used for the anastomosis, tumour T stage, histological margins, day one post-operative haemoglobin and whether a salivary bypass tube was used. Univariate and multivariate analysis were performed. A total of 199 patients were included and 24 received salivary bypass tubes. Fistula rates were 8.3% in the SBT group (2/24) and 24.6% in the control group (43/175). This was not statistically significant on univariate (p value 0.115) or multivariate analysis (p value 0.076). In addition, no other co-variables were found to be significant. No group has proven a benefit of salivary bypass tubes on multivariate analysis. The study was limited by a small case group, variations in tube duration and subjects given a tube may have been identified as high risk of fistula. Further prospective studies are warranted prior to recommendation of salivary bypass tubes following laryngectomy

Histopathological changes in the human larynx following expanded polytetrafluroethylene (Gore-Tex(®)) implantation

BACKGROUND: Expanded polytetrafluroethelyne (e PTFE, Gore-Tex(®)) has been advocated as an implant material for medialization of the vocal fold. Animal studies involving rabbits and a porcine model have demonstrated host tolerance of the implant. There have been no reports describing the histological changes in a human laryngectomy specimen with a Gore-Tex implant. CASE PRESENTATION: The histological findings in a laryngectomy specimen of a patient previously implanted with e PTFE for medialization of a paralyzed vocal fold following excision of a vagal neurofibroma were studied. Histopathology revealed a mild foreign-body giant cell granulomatous reaction with some associated fibrosis. The granulomatous response was limited to the periphery of the Gore-Tex and although it closely followed the profile of the material it did not encroach into or significantly break up the material. There was no significant neutrophilic or lymphocytic inflammation. CONCLUSIONS: Our findings are consistent with the animal models confirming that Gore-Tex implantation does not result in a significant granulomatous reaction in the human larynx over a 13-month period. Moreover, there is no evidence of resorption or infection. Further, the lack of lymphocytes in association with the granulomas indicates that there is no significant immunological hypersensitivity. Histologically, the slight permeation by connective tissue is similar to that seen in Gore-Tex vascular and cardiac implants. The degree of the slight giant cell response appears to be dependent on the profile of the material; a sharp edge incited more of a response than a flat surface

Targeting gammadelta regulatory T cell recruitment for breast cancer immunotherapy (TUM2P.904)

Abstract Immunosuppressive microenvironments induced by regulatory T cells (Treg) present a major barrier for successful anti-tumor immunotherapy. Understanding the mechanisms for the accumulation of different subtypes of Treg cells in the immunosuppressive tumor microenvironment is essential to improving cancer treatment. Enriched gammadelta1 T cell populations in tumor-infiltrating lymphocytes (TILs) suppress T cell responses and dendritic cell maturation in breast cancer, where their presence is correlated negatively with clinical outcomes. However, mechanism(s) that explain the increase in this class of gammadelta Treg cells in breast cancer patients have yet to be elucidated. In this study, we showed that IP-10 secreted by breast cancer cells attracted gammadelta Treg cells. Using neutralizing antibodies against chemokines secreted by breast cancer cells, we found that IP-10 was the only functional chemokine that causes gammadelta Treg cells to migrate toward breast cancer cells. In a humanized NSG mouse model, human breast cancer cells attracted gammadelta Treg cells as revealed by a live cell imaging system. IP-10 neutralization in vivo inhibited migration and trafficking of gammadelta Treg cells into breast tumor sites, enhancing tumor immunity mediated by tumor-specific T cells. Together, our studies show how gammadelta Treg cells accumulate in breast tumors, providing a rationale for their immunological targeting to relieve immunosuppression in the tumor microenvironment.</jats:p

Molecular control of human regulatory T cell suppression for tumor immunotherapy (P2106)

Abstract Immunotherapy is a promising approach for treating patients with malignant tumor, but immunosuppressive microenvironments induced by regulatory T cells (Tregs) present a major barrier to successful anti-tumor immunotherapy. A better understanding of the suppressive mechanisms utilized by Tregs is essential for the development of novel strategies to treat human cancer. Here we report that human Tregs can induce senescence in responder naïve and effector T cells in vitro and in vivo. Senescent responder T cells induced by human Tregs changed their phenotypes and cytokine profiles, and possessed potent suppressive function. Furthermore, Treg-mediated molecular control of senescence in responder T cells was associated with selective modulation of p38 and ERK1/2 signaling and cell cycle regulatory molecules p16, p21 and p53. We further revealed that human Treg-induced senescence and suppressor function could be blocked by TLR8 signaling and/or by specific ERK1/2 and p38 inhibition in vitro and in vivo in animal models. Our studies identify a novel mechanism of human Treg cell suppression that induces targeted responder T cell senescence, and provide new insights relevant for the development of strategies capable of preventing and/or reversing Treg-induced immune suppression for tumor immunotherapy.</jats:p

Abstract 4995: Tumor-dervied gammadelta regulatory T cells suppress innate and adaptive immunity through the induction of immunosenescence.

Abstract Fundamentally understanding the suppressive mechanisms utilized by different subsets of tumor-infiltrating regulatory T (Treg) cells is critical for the development of effective strategies for anti-tumor immunotherapy. Gammadelta Treg cells have recently been identified in human diseases including in cancer patients. However, the suppressive mechanisms and functional regulations of this new subset of unconventional Treg cells are largely unknown. In the current studies, we explored the suppressive mechanism(s) utilized by human breast tumor-derived gammadelta Treg cells on innate and adaptive immunity. We found that gammadelta Treg cells induced immunosenescence in targeted naïve and effector T cells, as well as dendritic cells (DCs). Furthermore, senescent T cells and DCs induced by gammadelta Treg cells had altered phenotypes and developed potent suppressive activities, further amplifying the immunosuppression mediated by gammadelta Treg cells. In addition, we demonstrated that manipulation of TLR8 signaling in gammadelta Treg cells can block gammadelta Treg-induced conversion of T cells and DCs into senescent cells in vitro and in vivo. Our studies identify the novel suppressive mechanism mediated by human tumor-derived gammadelta Treg cells on innate and adaptive immunity, which should be critical for development of strong and innovative approaches to reverse the tumor suppressive microenvironment and improve effects of immunotherapy. This work was supported by the grant from the American Cancer Society (RSG-10-160-01-LIB). Key words: gammadelta T cells; Regulatory T cells; Dendritic cells; Senescence; Immune suppression Citation Format: Jian Ye, Chunling Ma, Eddy C. Hsueh, Yanping Zhang, Mark A. Varvares, Daniel F. Hoft, Guangyong Peng. Tumor-dervied gammadelta regulatory T cells suppress innate and adaptive immunity through the induction of immunosenescence. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4995. doi:10.1158/1538-7445.AM2013-4995</jats:p