Characterization of natural killer and cytotoxic T-cell immune infiltrates in pancreatic ductal adenocarcinoma

BACKGROUND AND OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with poor response to systemic therapies, including immunotherapy. Given the immunotherapeutic potential of natural killer (NK) cells, we evaluated intratumoral NK cell infiltrates along with cytotoxic T cells in PDAC to determine their association with patient outcomes.

METHODS

We analyzed tumors from 93 PDAC patients treated from 2012 to 2020. Predictor variables included tumor-infiltrating lymphocytes (TILs), T-cell markers (CD3, CD8, CD45RO), NK marker (NKp46), and NK inhibitory marker (major histocompatibility complex class I [MHC-I]) by immunohistochemistry. Primary outcome variables were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Mean TILs, CD3, and NKp46 scores were 1.3 ± 0.63, 20.6 ± 17.5, and 3.1 ± 3.9, respectively. Higher expression of CD3 and CD8 was associated with higher OS, whereas NK cell infiltration was not associated with either RFS or OS. There was a tight positive correlation between MHC-I expression and all T-cell markers, but not with NKp46.

CONCLUSIONS

Overall NK cell infiltrates were low in PDAC and did not predict clinical outcomes, whereas T-cell infiltrates did. Further characterization of the immune infiltrate in PDAC, including inhibitory signals and suppressive cell types, may yield better biomarkers of prognosis and immune targeting in this refractory disease.

Intratumoral NKp46+ natural killer cells are spatially distanced from T and MHC-I+ cells with prognostic implications in soft tissue sarcoma

Introduction

Soft tissue sarcomas (STS) are rare, heterogenous malignancies with an unmet need for novel immunotherapies. Tumor infiltrating lymphocytes (TILs) have been linked with favorable outcomes in STS patients, though the contribution of natural killer (NK) cells and spatial relationships of TILs with MHC-I expressing cells lacks detailed characterization.

Experimental design

Using archived and prospectively collected specimens, we evaluated intratumoral NK cells by immunohistochemistry (IHC), flow cytometry, and immunofluorescence (IF). We assessed spatial localization of NK and T cells by multiplex IF, analyzing the effects of MHC-I expression status on NK and T cell clustering.

Results

Both intratumoral NKp46 and CD56dim expression were associated with significantly improved overall survival (P=0.05), while higher infiltrates of CD56bright NK cells predicted a worse prognosis (P=0.05). The presence of intratumoral NK cells was inversely proportional to CD3+ T cells. Spatial analyses showed NK cells preferentially clustering close to other NK cells with sparse CD3+ T and CD8+ T cells in range (P<0.0001). Additionally, CD3+ T and CD8+ T cells showed significantly greater co-localization with MHC-I+ cells, compared to NK cells (P<0.0001). After neoadjuvant radiotherapy, there was greater CD8 clustering, while after neoadjuvant chemotherapy, there was overall lower TIL clustering.

Conclusion

Intratumoral NK cells are prognostic in STS and localize closer to MHC-I- cells than T cells. Although both NK and T cells are associated with improved survival in STS, their differential distribution in the TME based on MHC-I expression status may serve as a biomarker for improved immunotherapy treatment selection.

Higher Education and the Ethic of Care: Finding a Way Forward During a Global Pandemic

At the outset of the coronavirus pandemic, before we had a chance to acclimate to our world turned upside-down, I was genuinely confounded by the inflexibility of some professors to help students. After all, we had been offered the grace of an extension on tenure-track requirements, and afforded the opportunity, and relative safety, of working from home. How was it possible then, to not understand that students, too, might need grace? And how could anyone be OK with choosing not to help? Far from traditional research questions, my wonderings provoked lively conversations with colleagues, and a lens through which to consider my own positionality and difficulties in dealing with the challenges posed by the pandemic. Framed by Nel Noddings' Ethic of Care, and through poetic inquiry, this article presents a personal response to teaching in an Educator Preparation Program during a global pandemic.

Urban Productivity and the Neighborhoods: The Case for a Federal Neighborhood Strategy

In this paper the authors seek to build a new case for neighborhood-oriented government programs, primarily based on economic, rather than moral, political, or social policy considerations. Serious government investment can provide a base for much expanded service sector employment in neighborhoods in the central city and aging suburbs. Agglomeration effects in expanding service industries remain important for productivity, in spite of decentralization. Furthermore, the costs of decentralization impose constraints on further suburban growth. Urban neighborhoods can provide relatively high-productivity locales for service industries, because of existing infrastructure, a large labor force, proximity to downtowns, local entrepreneurs, and the enduring advantages of density. However, programs are needed to improve public infrastructure to increase productivity; invest in human capital; and strengthen the competitive position of neighborhoods through quality-of-life improvements.

Impact studies, cost-benefit analysis and casinos

The simplest forms of impact analysis treat a prospective casino facility as an entirely new source of demand in a region, while completely ignoring the character of supply responses. Such approaches cannot be used to estimate the net benefits of a casino. On the demand side they fail to consider the displacement of other local goods and services, while on the supply side they ignore the fact that most workers have real opportunity costs in the form of alternative employments either inside or outside the region. While various studies have attempted to address the displacement issue, virtually none have looked seriously at the opportunity cost of labor. Evidence suggests that such costs are large. An estimate presented here for Chicago sets these costs at 45% of casino and related labor income.

Femoral-tibial bypass for calcific arterial disease

Overt calcification of the recipient artery and outflow bed has been regarded as a poor prognostic factor for femoral-distal arterial bypass patency and subsequent wound healing. In order to determine the short- and long-term limb salvage and graft patency rates achieved in these patients, the records of 35 patients undergoing 38 attempted femoral-tibial bypasses to a calcified recipient artery were reviewed. Two patients were unreconstructable at the time of surgery. Thirty-one of the 36 operations (86 percent) were performed using in situ saphenous vein bypass techniques, 3 were performed with polytetrafluoroethylene (PTFE), 1 with a composite sequential, and 1 with a composite vein graft. Immediate limb salvage was achieved in 31 of 36 limbs (86 percent). Five early below-knee amputations (14 percent) were required, two due to graft thromboses and three due to progressive foot necrosis despite patent grafts. One patient (3 percent) died secondary to sepsis. Three-year primary graft patency and limb salvage rates did not differ significantly from bypasses to noncalcified vessels. Femoral-distal bypass in the presence of overt calcific arterial disease may be successfully accomplished and offers an excellent prognosis for long-term graft patency and limb salvage.

Effect of hemodilution on brain tissue during global ischemia

This study evaluates the effect of blood volume and hematocrit changes on brain tissue during temporary global ischemia. Normal saline was administered intravenously to 55 gerbils to achieve hypo-, normo-, and hypervolemic hemodilution and uniform 30% hematocrit reduction. Each group had unilateral carotid artery ligation and temporary (20 minute) contralateral carotid occlusion. After ten days or death, brains were harvested, preserved in formalin, sectioned in a manner which provided adequate samples of both cortex and hippocampus, and stained with H&E and luxol fast blue. They were then examined and staged microscopically for white and gray matter infarction, edema, and neuronal injury and loss. Histologic studies were performed in a randomized and blinded manner and were classified by one of four categories: normal, minimal, moderate, and severe changes. Three of ten (30%) controls survived ten days but had severe neuronal loss, minimal cerebral edema and a minimal to moderate number of white matter strokes. Survival was best in animals treated with hypovolemic hemodilution (43%). Other rates were: normovolemic (33%), controls (30%), and hypervolemic (8.3%). The degree of brain tissue damage was markedly less in the normovolemic group. In this model, normovolemic hemodilution followed by hypovolemic hemodilution offered the best overall cerebral protection during global ischemia.