CD8+ T cell activation in cancer comprises an initial activation phase in lymph nodes followed by effector differentiation within the tumor.

Improvements in tumor immunotherapies depend on better understanding of the anti-tumor T cell response. By studying human tumor-draining lymph nodes (TDLNs), we found that activated CD8+ T cells in TDLNs shared functional, transcriptional, and epigenetic traits with TCF1+ stem-like cells in the tumor. The phenotype and TCR overlap suggested that these TDLN cells were precursors to tumor-resident stem-like CD8+ T cells. Murine tumor models revealed that tumor-specific CD8+ T cells were activated in TDLNs but lacked an effector phenotype. These stem-like cells migrated into the tumor, where additional co-stimulation from antigen-presenting cells drove effector differentiation. This model of CD8+ T cell activation in response to cancer is different from that of canonical CD8+ T cell activation to acute viruses, and it proposes two stages of tumor-specific CD8+ T cell activation: initial activation in TDLNs and subsequent effector program acquisition within the tumor after additional co-stimulation.

Differentiation fate of a stem-like CD4 T cell controls immunity to cancer.

The T cell response to cancer controls disease progression and response to immunotherapy1-3. Despite extensive knowledge regarding CD8 T cells, how CD4 T cells contribute to this process is less well understood. Here we identified a population of PD1+TCF1+ CD4 T cells with stem-like properties that are capable of self-renewal and differentiation into canonical CD4 effector cells. Primarily residing in tumour-draining lymph nodes (TDLNs), these tumour-specific CD4 T cells are restricted by T regulatory (Treg) cells to a stem-like fate that predominantly generated induced Treg (iTreg) cells, limiting effector CD8 T cell responses to the tumour. By contrast, upon Treg depletion, stem-like CD4 T cells differentiated into T helper 1 (TH1) cells, and via IFNγ production induced robust effector differentiation from TCF1+ CD8 T cells in TDLNs, a state we defined as 'active'. Notably, enforcing TBET expression in transferred stem-like CD4 T cells was sufficient to overcome the established restricted T cell state. Despite the presence of Treg cells, endogenous stem-like CD4 T cells actively generated TH1 cells, which were required to restore TDLN effector CD8 T cell differentiation, enhance tumour control and rescue response to immunotherapy. In agreement, TH1 differentiation in patients with kidney cancer predicted successful immunotherapy responses and improved progression-free survival. Together, these findings identify a stem-like CD4 T cell population that through alternative differentiation fates controls the switch between restricted and active T cell states with implications for cancer immunotherapies.

PD-1 combination therapy with IL-2 modifies CD8+ T cell exhaustion program.

Combination therapy with PD-1 blockade and IL-2 is highly effective during chronic lymphocytic choriomeningitis virus infection1. Here we examine the underlying basis for this synergy. We show that PD-1 + IL-2 combination therapy, in contrast to PD-1 monotherapy, substantially changes the differentiation program of the PD-1+TCF1+ stem-like CD8+ T cells and results in the generation of transcriptionally and epigenetically distinct effector CD8+ T cells that resemble highly functional effector CD8+ T cells seen after an acute viral infection. The generation of these qualitatively superior CD8+ T cells that mediate viral control underlies the synergy between PD-1 and IL-2. Our results show that the PD-1+TCF1+ stem-like CD8+ T cells, also referred to as precursors of exhausted CD8+ T cells, are not fate-locked into the exhaustion program and their differentiation trajectory can be changed by IL-2 signals. These virus-specific effector CD8+ T cells emerging from the stem-like CD8+ T cells after combination therapy expressed increased levels of the high-affinity IL-2 trimeric (CD25-CD122-CD132) receptor. This was not seen after PD-1 blockade alone. Finally, we show that CD25 engagement with IL-2 has an important role in the observed synergy between IL-2 cytokine and PD-1 blockade. Either blocking CD25 with an antibody or using a mutated version of IL-2 that does not bind to CD25 but still binds to CD122 and CD132 almost completely abrogated the synergistic effects observed after PD-1 + IL-2 combination therapy. There is considerable interest in PD-1 + IL-2 combination therapy for patients with cancer2,3, and our fundamental studies defining the underlying mechanisms of how IL-2 synergizes with PD-1 blockade should inform these human translational studies.

Defining HPV-specific B cell responses in patients with head and neck cancer.

Tumours often contain B cells and plasma cells but the antigen specificity of these intratumoral B cells is not well understood1-8. Here we show that human papillomavirus (HPV)-specific B cell responses are detectable in samples from patients with HPV-positive head and neck cancers, with active production of HPV-specific IgG antibodies in situ. HPV-specific antibody secreting cells (ASCs) were present in the tumour microenvironment, with minimal bystander recruitment of influenza-specific cells, suggesting a localized and antigen-specific ASC response. HPV-specific ASC responses correlated with titres of plasma IgG and were directed against the HPV proteins E2, E6 and E7, with the most dominant response against E2. Using intratumoral B cells and plasma cells, we generated several HPV-specific human monoclonal antibodies, which exhibited a high degree of somatic hypermutation, consistent with chronic antigen exposure. Single-cell RNA sequencing analyses detected activated B cells, germinal centre B cells and ASCs within the tumour microenvironment. Compared with the tumour parenchyma, B cells and ASCs were preferentially localized in the tumour stroma, with well-formed clusters of activated B cells indicating ongoing germinal centre reactions. Overall, we show that antigen-specific activated and germinal centre B cells as well as plasma cells can be found in the tumour microenvironment. Our findings provide a better understanding of humoral immune responses in human cancer and suggest that tumour-infiltrating B cells could be harnessed for the development of therapeutic agents.

Functional HPV-specific PD-1+ stem-like CD8 T cells in head and neck cancer.

T cells are important in tumour immunity but a better understanding is needed of the differentiation of antigen-specific T cells in human cancer1,2. Here we studied CD8 T cells in patients with human papillomavirus (HPV)-positive head and neck cancer and identified several epitopes derived from HPV E2, E5 and E6 proteins that allowed us to analyse virus-specific CD8 T cells using major histocompatibility complex (MHC) class I tetramers. HPV-specific CD8 T cells expressed PD-1 and were detectable in the tumour at levels that ranged from 0.1% to 10% of tumour-infiltrating CD8 T lymphocytes (TILs) for a given epitope. Single-cell RNA-sequencing analyses of tetramer-sorted HPV-specific PD-1+ CD8 TILs revealed three transcriptionally distinct subsets. One subset expressed TCF7 and other genes associated with PD-1+ stem-like CD8 T cells that are critical for maintaining T cell responses in conditions of antigen persistence. The second subset expressed more effector molecules, representing a transitory cell population, and the third subset was characterized by a terminally differentiated gene signature. T cell receptor clonotypes were shared between the three subsets and pseudotime analysis suggested a hypothetical differentiation trajectory from stem-like to transitory to terminally differentiated cells. More notably, HPV-specific PD-1+TCF-1+ stem-like TILs proliferated and differentiated into more effector-like cells after in vitro stimulation with the cognate HPV peptide, whereas the more terminally differentiated cells did not proliferate. The presence of functional HPV-specific PD-1+TCF-1+CD45RO+ stem-like CD8 T cells with proliferative capacity shows that the cellular machinery to respond to PD-1 blockade exists in HPV-positive head and neck cancer, supporting the further investigation of PD-1 targeted therapies in this malignancy. Furthermore, HPV therapeutic vaccination efforts have focused on E6 and E7 proteins; our results suggest that E2 and E5 should also be considered for inclusion as vaccine antigens to elicit tumour-reactive CD8 T cell responses of maximal breadth.

Organized immune cell interactions within tumors sustain a productive T-cell response.

Tumor-infiltrating CD8 T cells are associated with improved patient survival and response to immunotherapy in various cancers. Persistent antigen leads to CD8 T-cell exhaustion, where proliferation/self-renewal and killing are divided within distinct subsets of CD8 T cells in the tumor. CD8 T-cell responses in chronic antigen settings must be maintained for long periods of time, suggesting that mechanisms that regulate chronic CD8 T-cell responses may differ from those in acute settings. Currently, factors that regulate the maintenance of stem-like CD8 T cells in the tumor or their differentiation into terminally differentiated cells are unknown. In this review, we discuss the role of dendritic cells in the activation and differentiation of CD8 T-cell subsets within secondary lymphoid tissue and tumors. In addition, we examine changes in CD4 T-cell differentiation in response to chronic antigens and consider how subset-specific mechanisms could assist the stem-like and terminally differentiated CD8 T-cell subsets. Finally, we highlight how tumor-infiltrating CD4 T cells and dendritic cells interact with CD8 T cells within organized lymphoid-like areas in the tumor and propose a CD8 T-cell differentiation model that requires the collaboration of CD4 T cells and dendritic cells. These organized interactions coordinate the anti-tumor response and control disease progression by mechanisms that regulate CD8 T-cell differentiation, which permit the maintenance of an effective balance of stem-like and terminally differentiated CD8 T cells.

Early generation of a precursor CD8 T cell that can adapt to acute or chronic viral infection.

Virus specific PD-1+ TCF-1+ TOX+ stem-like CD8+ T cells are essential for maintaining T cell responses during chronic infection and are also critical for PD-1 directed immunotherapy. In this study we have used the mouse model of chronic LCMV infection to examine when these virus specific stem-like CD8+ T cells are generated during the course of chronic infection and what is the role of antigen in maintaining the stem-like program. We found that these stem-like CD8+ T cells are generated early (day 5) during chronic infection and that antigen is essential for maintaining their stem-like program. This early generation of stem-like CD8+ T cells suggested that the fate commitment to this cell population was agnostic to the eventual outcome of infection and the immune system prepares a priori for a potential chronic infection. Indeed, we found that an identical virus specific stem-cell like CD8+ T cell population was also generated during acute LCMV infection but these cells were lost once the virus was cleared. To determine the fate of these early PD-1+TCF-1+TOX+ stem-like CD8+ T cells that are generated during both acute and chronic LCMV infection we set up two reciprocal adoptive transfer experiments. In the first experiment we transferred day 5 stem-like CD8+ T cells from chronically infected into acutely infected mice and examined their differentiation after viral clearance. We found that these early stem-like CD8+ T cells downregulated canonical markers of the chronic stem-like CD8+ T cells and expressed markers (CD127 and CD62L) associated with central memory CD8+ T cells. In the second experiment, we transferred day 5 stem-like cells from acutely infected mice into chronically infected mice and found that these CD8+ T cells could function like resource cells after transfer into a chronic environment by generating effector CD8+ T cells in both lymphoid and non-lymphoid tissues while also maintaining the number of stem-like CD8+ T cells. These findings provide insight into the generation and maintenance of virus specific stem-like CD8+ T cells that play a critical role in chronic viral infection. In particular, our study highlights the early generation of stem-like CD8+ T cells and their ability to adapt to either an acute or chronic infection. These findings are of broad significance since these novel stem-like CD8+ T cells play an important role in not only viral infections but also in cancer and autoimmunity.

Pre-operative stereotactic radiosurgery and peri-operative dexamethasone for resectable brain metastases: a two-arm pilot study evaluating clinical outcomes and immunological correlates.

Enhancing the efficacy of immunotherapy in brain metastases (BrM) requires an improved understanding of the immune composition of BrM and how this is affected by radiation and dexamethasone. Our two-arm pilot study (NCT04895592) allocated 26 patients with BrM to either low (Arm A) or high (Arm B) dose peri-operative dexamethasone followed by pre-operative stereotactic radiosurgery (pSRS) and resection (n= 13 per arm). The primary endpoint, a safety analysis at 4 months, was met. The secondary clinical endpoints of overall survival, distant brain failure, leptomeningeal disease and local recurrence at 12-months were 66%, 37.3%, 6%, and 0% respectively and were not significantly different between arms (p= 0.7739, p= 0.3884, p= 0.3469). Immunological data from two large retrospective BrM datasets and confirmed by correlates from both arms of this pSRS prospective trial revealed that BrM CD8 T cells were composed of predominantly PD1+ TCF1+ stem-like and PD1+ TCF1-TIM3+ effector-like cells. Clustering of TCF1+ CD8 T cells with antigen presenting cells in immune niches was prognostic for local control, even without pSRS. Following pSRS, CD8 T cell and immune niche density were transiently reduced compared to untreated BrM, followed by a rebound 6+ days post pSRS with an increased frequency of TCF1- effector-like cells. In sum, pSRS is safe and therapeutically beneficial, and these data provide a framework for how pSRS may be leveraged to maximize intracranial CD8 T cell responses.

Platinum-based chemotherapy attenuates the effector response of CD8 T cells to concomitant PD-1 blockade.

PURPOSE: Combination of chemotherapy (CT) with programmed cell death (PD)-1 blockade is a front-line treatment for lung cancer. However, it remains unknown whether and how CT affects the response of exhausted CD8 T cells to PD-1 blockade. EXPERIMENTAL DESIGN: We used the well-established mouse model of T cell exhaustion with chronic lymphocytic choriomeningitis virus (LCMV) infection to assess the effect of CT (cisplatin+pemetrexed) on T cell response to PD-1 blockade, in the absence of the impact of CT on antigen release and presentation observed in tumor models. RESULTS: When concomitantly administered with PD-1 blockade, CT affected the differentiation path of LCMV-specific CD8 T cells from stem-like to transitory effector cells, thereby reducing their expansion and production of interferon (IFN)-γ. After combination treatment, these restrained effector responses resulted in impaired viral control, compared to PD-1 blockade alone. The sequential combination strategy, where PD-1 blockade followed CT, proved to be superior to the concomitant combination, preserving the proliferative response of exhausted CD8 T cells to PD-1 blockade. Our findings suggest that the stem-like CD8 T cells themselves are relatively unaffected by CT partly because they are quiescent and maintained by slow self-renewal at the steady state. However, upon the proliferative burst mediated by PD-1 blockade, the accelerated differentiation and self-renewal of stem-like cells may be curbed by concomitant CT, ultimately resulting in impaired overall CD8 T cell effector functions. CONCLUSIONS: In a translational context, we provide a proof-of-concept to consider optimizing the timing of chemo-immunotherapy strategies for improved CD8 T cell functions.

The immunosuppressive phenotype of tumor-infiltrating neutrophils is associated with obesity in kidney cancer patients.

Infiltrating tumor neutrophils and myeloid-derived suppressor cells represent major populations in the tumor microenvironment that contribute to tumor progression. However, the phenotype of circulating and tumor-associated neutrophils, and the impact of cancer patients' metabolic state on neutrophil function need further characterization. Here we show that in kidney cancer patients, circulating neutrophils display an altered immature-like phenotype, and an activated/primed metabolic state. Circulating immature-like neutrophils acquire an activated phenotype upon migration into the tumor tissue, characterized by high expression of the immunosuppressive enzyme arginase-1, and active granule release. Interestingly, obesity and adipose tissue distribution were significantly associated with this activated phenotype of neutrophils, including the release of arginase-1 in the tumor tissue. These results provide a possible functional relationship between the metabolic status of the patients and disease progression, through an active immunosuppressive role of neutrophils within the kidney tumor microenvironment.

Hypoglycemic Activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on Wistar Rats.

Diabetes mellitus (DM) is considered the epidemic of the 21st century. Traditional medicine uses plants to treat DM; many of these have hypoglycemic effects in both animal models and diabetic patients. Our objective was to evaluate the hypoglycemic activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on diabetic rats. The methanolic extracts of the plants under study were obtained by Soxhlet extraction. Toxicity was evaluated on Artemia salina; the antioxidant potential was evaluated using the DPPH technique. Hypoglycemic capacity at doses of 250 and 500 mg/kg was tested on Wistar rats with diabetes induced by alloxan (120 mg/kg). The toxicity on A. salina was null for the extracts of B. officinalis and P. sanctum, moderate for T. americana, and highly toxic for C. nuttalliae. The relevant extract of T. americana var. mexicana showed antioxidant activity. Three plants of the studied plants showed hypoglycemic activity: Tilia Americana (p = 0.0142), Borago officinalis (p = 0.0112), and Piper sanctum (p = 0.0078); P. sanctum was the one that showed the greatest reduction in glucose levels at a lower dose.

Safety of Aqueous Extract of Calea ternifolia Used in Mexican Traditional Medicine.

There is a trend to use medicinal plants for primary medical care or as dietary supplements; however, the safety of many of these plants has not been studied. The objective of this work was to determine the toxic effect of the aqueous extract of Calea ternifolia (C. zacatechichi), known popularly as "dream herb" in vivo and in vitro in order to validate its safety. In vivo, the extract had moderate toxicity on A. salina. In vitro, the extract induced eryptosis of 73% at a concentration of 100 µg·mL-1 and it inhibited CYP3A by 99% at a concentration of 375 µg/mL. After administering 8.5 mg/kg of C. ternifolia to rats, we found a reduction in platelets and leukocytes and an increase in urea and the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Histological analysis showed spongiform changes in the proximal tubules of renal tissue and a lymphoid infiltrate in liver tissue. This plant is used in the treatment of diabetes, and it is commercialized as a dietary supplement in several countries. Our results show renal and hepatic toxicity; therefore, more profound research on the toxicity of this plant is needed.

Tumores de las fosas nasales y senos paranasales. Tumores no epiteliales / Tumors of the nasal fossae and paranasal sinuses. Non epithelial tumors

Los tumores no epiteliales de las fosas nasales incluyen tumores de origen mesectodérmicos y neuroectodérmicos. Las neoplasias mesectodérmicas mas frecuentes son los vasculares y de estos los angiofibromas son los mas frecuentes y le siguen los hemangiomas, los angiosarcomas son excepcionales, Los linfomas son raros no obstante el anillo de Waldeyer. Los mixomas son frecuentes y por su vecindad con la órbita y la cavidad craneana aunque su comportamiento es benigno son muy destructivos y pueden llevar a la muerte. Dentro de los sarcomas lo rabdomiosarcomas son los mas frecuentes

Diagnóstico citológico de la conjuntivitis por Chalmydia trachomatis / Citologic diagnosis of conjuntivitis infections by Chlamydia trachomatis

Clínicamente no es posible establecer el diagnóstico de las infecciones conjuntivales por Chlamidya trachomatis, por lo que se han buscado métodos de laboratorio ideales y aplicables a un gran grupo de población. Losmétodos que se describen en el texto son complejos y no estan al alcance del oftalmólogo en nuestro país. La citología exfoliativa podría ser el método de elección por ser de bajo costo, fácil en su proceso, rápido, disponible en cualquier institución que cuente con patólogo ocular, dispomible para la clínica y de acuerdo a nuestra experiencia con muy alto índice de acierto, ya que no existen falsas positivas.

Diagnóstico diferencial de la queratoconjuntivitis / Early diagnosis of the follicular conjuntivitis

Las conjuntivitis foliculares en nuestro país, son producidas por Chlamydia trachomatis, adenovirus, herpes virus, hongos, bacterias y respuesta inmune. El diagnóstico etiológico no es posible realizarlo con precisión por los datos clínicos únicamente. Los métodos tradicionales (cultivos) no son de utilidad en infecciones por Chlamydia trachomatis, herpes virus o adenovius. Los métodos diagnósticos específicos para cada uno de estos agentes, son caros, complejos y no están disponibles en nuestro país. Los autores presentan la experiencia del estudio citológico de 1,679 casos de conjuntivis folicular. Los autores recomiendan la citología exfoliativa como el método idóneo en el diagnóstico diferencial de las conjuntivitis

Glioneuroma asociado a anoftalmía / Glioneuroma associated to anophthalmia

Se presenta un caso de glioneuroma de órbita izquierda asociado a anoftalmía bilateral y quiste meníngeo, en un recién nacido con múltiples anomalías congénitas y con historia familiar de retraso mental y disontogenias. El glioneuroma es una neoplasia benigna constituida por células gliales, neuronas y un neurópilo de fondo. Se demostró el componente astroglial y clasmatodendrítico por medio de técnicas histoinmunoquímicas

Tumores disontogénicos del globo ocular y sus anexos. I. Introducción, aspectos básicos y hamartomas / Disontogenic tumors of the eye and ocular anexa. Introduction, basic principles and hamartomas

Los tumores disontogénicos son lesiones proliferativas que se originan como un trastorno del desarrollo e incluyen una variedad de neoformaciones: Hamartomas, coristomas y el complejo grupo de los teratomas. La mayoría de estas lesiones son benignas con excepción de los teratomas. Son entidades algunas de ellas frecuentes en la clínica y otras son excepcionales. El tratamiento es quirúrgico y el pronóstico es bueno en la mayoría de los casos. Es un grupo de lesiones poco conocidas en la clínica oftalmológica. Se hace una revisión completa del tema en tres partes. Los hamartomas pueden ser simples o complejos y las características histopatológicas y la taxonómicas dependen de sus componentes tisulares. Afectan a la órbita, párpados, conjuntiva, córnea y túnicas internas

Tumores disontogénicos del globo ocular y sus anexos. II. Coristomas / Disontogenic tumors of the eye and ocular anexa. II. Coristomas

Los coristomas se dividen en simples y complejos. Los coristomas simples más frecuentes son: Dermoides sólidos y quísticos, quistes epidérmicos, osteoma epibulbar, osteoma coroideo, glándula lagrimal aberrante y coristoma facomatoso. Los coristomas complejos varían dependiendo de la diversificación de sus elementos constitutivos, se incluye en este grupo como entidad individual al glioneuroma. Se hace una revisión del tema y se presentan las imágenes clínico-patológicas más sobresalientes

Tumores disontogénicos del globo ocular y sus anexos. III. Teratomas / Disontogenic tumors of the eye and ocular anexa. III. Teratomas

Los teratomas son neoplasias presentes desde el nacimiento en la mayoría de los casos, según su localización pueden ser gonadales y extragonadales, dentro de estos últimos la localización facial extracraneana es rara (1.7 por ciento). En la órbita es excepcional pero es la única localización oftalmológica descrita hasta el momento actual. De acuerdo a su comportamiento biológico pueden ser benignos o malignos y se discute la clasificación actual y gradación pronóstica. El tratamiento es quirúrgico y en las variedades malignas las quimioterapia y radioterapia pueden ser útiles. Se presentan los aspectos histopatológicos más sobresalientes y su correlación clínica

Coristoma complejo epibulbar / Complex epibulbal coristoma

Se presenta un caso de coristoma complejo epibulbar constituido predominantemente por tejido linfático folicular con centros reactivos, tejido adiposo, complejos pilosebáceos y glándula lagrimal. El diagnóstico fue histopatológico. Es una neoformación benigna de naturaleza disontogénica y el tratamiento es exclusivamente quirúrgico