Discovery and prioritization of somatic mutations in diffuse large B-cell lymphoma (DLBCL) by whole-exome sequencing

To gain insight into the genomic basis of diffuse large B-cell lymphoma (DLBCL), we performed massively parallel whole-exome sequencing of 55 primary tumor samples from patients with DLBCL and matched normal tissue. We identified recurrent mutations in genes that are well known to be functionally relevant in DLBCL, including MYD88, CARD11, EZH2, and CREBBP. We also identified somatic mutations in genes for which a functional role in DLBCL has not been previously suspected. These genes include MEF2B, MLL2, BTG1, GNA13, ACTB, P2RY8, PCLO, and TNFRSF14. Further, we show that BCL2 mutations commonly occur in patients with BCL2/IgH rearrangements as a result of somatic hypermutation normally occurring at the IgH locus. The BCL2 point mutations are primarily synonymous, and likely caused by activation-induced cytidine deaminase-mediated somatic hypermutation, as shown by comprehensive analysis of enrichment of mutations in WRCY target motifs. Those nonsynonymous mutations that are observed tend to be found outside of the functionally important BH domains of the protein, suggesting that strong negative selection against BCL2 loss-of-function mutations is at play. Last, by using an algorithm designed to identify likely functionally relevant but infrequent mutations, we identify KRAS, BRAF, and NOTCH1 as likely drivers of DLBCL pathogenesis in some patients. Our data provide an unbiased view of the landscape of mutations in DLBCL, and this in turn may point toward new therapeutic strategies for the disease.     

Lack of intrafollicular memory CD4 + T cells is predictive of early clinical failure in newly diagnosed follicular lymphoma

Despite a characteristic indolent course, a substantial subset of follicular lymphoma (FL) patients has an early relapse with a poor outcome. Cells in the microenvironment may be a key contributor to treatment failure. We used a discovery and validation study design to identify microenvironmental determinants of early failure and then integrated these results into the FLIPI. In total, 496 newly diagnosed FL grade 1–3 A patients who were prospectively enrolled into the MER cohort from 2002 to 2012 were evaluated. Tissue microarrays were stained for CD4, CD8, FOXP3, CD32b, CD14, CD68, CD70, SIRP-α, TIM3, PD-1, and PD-L1. Early failure was defined as failing to achieve event-free survival at 24 months (EFS24) in immunochemotherapy-treated patients and EFS12 in all others. CyTOF and CODEX analysis were performed to characterize intratumoral immunophenotypes. Lack of intrafollicular CD4 expression was the only predictor of early failure that replicated with a pooled OR 2.37 (95%CI 1.48–3.79). We next developed a bio-clinical risk model (BioFLIPI), where lack of CD4 intrafollicular expression moved patients up one FLIPI risk group, adding a new fourth high-risk group. Compared with BioFLIPI score of 1, patients with a score of 2 (OR 2.17; 95% CI 1.08–4.69), 3 (OR 3.53; 95% CI 1.78–7.54), and 4 (OR 8.92; 95% CI 4.00–21.1) had increasing risk of early failure. The favorable intrafollicular CD4 T cells were identified as activated central memory T cells, whose prognostic value was independent from genetic features. In conclusion, lack of intrafollicular CD4 expression predicts early failure in FL and combined with FLIPI improves identification of high-risk patients; however, independent validation is warranted.Subject terms: Cancer microenvironment, CD4-positive T cells     

IL-10 induces the development of immunosuppressive CD14+HLA-DRlow/? monocytes in B-cell non-Hodgkin lymphoma

The biological role of monocytes and macrophages in B-cell non-Hodgkin lymphoma (NHL) is not fully understood. We have previously reported that monocytes from patients with B-cell NHL have an immunosuppressive CD14⁺HLA-DR^low/− phenotype that correlates with a poor prognosis. However, the underlying mechanism by which CD14⁺HLA-DR^low/− monocytes develop in lymphoma is unknown. In the present study, we found that interleukin (IL)-10, which is increased in the serum of patients with B-cell NHL, induced the development of the CD4⁺HLA-DR^low/− population. Using peripheral blood samples from patients with B-cell NHL, we found that absolute numbers of CD14⁺ monocytic cells with an HLA-DR^low/− phenotype were higher than healthy controls and correlated with a higher International Prognostic Index score. IL-10 serum levels were elevated in lymphoma patients compared with controls and were associated with increased peripheral monocyte counts. Treatment of monocytes with IL-10 in vitro significantly decreased HLA-DR expression and resulted in the expansion of CD14⁺HLA-DR^low/− population. We found that lymphoma B cells produce IL-10 and supernatants from cultured lymphoma cells increased the CD14⁺HLA-DR^low/− population. Furthermore, we found that IL-10-induced CD14⁺HLA-DR^low/− monocytes inhibited the activation and proliferation of T cells. Taken together, these results suggest that elevated IL-10 serum levels contribute to increased numbers of immunosuppressive CD14⁺HLA-DR^low/− monocytes in B-cell NHL.     

From the Cover: Inhaled oxytocin increases positive social behaviors in newborn macaques

Early caregiver–infant interactions are critical for infants’ socioemotional and cognitive development. Several hormones and neuromodulators, including oxytocin, affect these interactions. Exogenous oxytocin promotes social behaviors in several species, including human and nonhuman primates. Although exogenous oxytocin increases social function in adults—including expression recognition and affiliation—it is unknown whether oxytocin can increase social interactions in infants. We hypothesized that nebulized oxytocin would increase affiliative social behaviors and such effects would be modulated by infants’ social skills, measured earlier in development. We also hypothesized that oxytocin’s effects on social behaviors may be due to its anxiolytic effects. We tested these hypotheses in a blind study by nebulizing 7- to 14-d-old macaques (n = 28) with oxytocin or saline. Following oxytocin administration, infants’ facial gesturing at a human caregiver increased, and infants’ salivary oxytocin was positively correlated with the time spent in close proximity to a caregiver. Infants’ imitative skill (measured earlier in development: 1–7 d of age) predicted oxytocin-associated increases in affiliative behaviors—lip smacking, visual attention to a caregiver, and time in close proximity to a caregiver—suggesting that infants with higher propensities for positive social interactions are more sensitive to exogenous oxytocin. Oxytocin also decreased salivary cortisol, but not stress-related behaviors (e.g., scratching), suggesting the possibility of some anxiolytic effects. To our knowledge, this study provides the first evidence that oxytocin increases positive social behaviors in newborns. This information is of critical importance for potential interventions aimed at ameliorating inadequate social behaviors in infants with higher likelihood of developing neurodevelopmental disorder.Oxytocin is a neuropeptide that has wide-ranging effects on social behaviors and social perception, including increased emotion recognition and prosocial behavior (1, 2). Animal studies present convergent evidence of oxytocin’s positive effects on social behavior (2–6), including humans (1, 7). In recent years, an increasing literature on human and nonhuman primates suggests an association between oxytocin levels—either endogenous or exogenously administered—and prosocial behaviors (8–10). In both humans and macaques, exogenous oxytocin appears to enhance social attention, prosocial behaviors, sensitivity to gaze, and sensitivity to facial expressions (for reviews, see refs. 1 and 2).Oxytocin, therefore, may be a tool for promoting social behaviors, especially in clinical populations in which social faculties are compromised (8, 11–13). In the last few years, in fact, oxytocin has been tested in autistic individuals, and it appears to increase social attention and improve emotion recognition (e.g., refs. 14–19; although see ref. 20; for a recent review, see ref. 21). Given the importance of early assessments in the diagnosis of autism (22), studies clarifying the role of oxytocin in early development are critically important. For example, human infants actively participate in face-to-face caregiver–infant interactions; failure to engage with caregivers in this way can disrupt the development of healthy emotion regulation and socioemotional skills (23–25). In both caregivers and neonates, complex cortical and limbic brain networks are prepared to sustain such exchanges (26–28), and several hormones and neuromodulators regulate the affective components of face-to-face caregiver–infant interactions (29–32). However, to our knowledge, studies investigating the role of infants’ oxytocin levels in these early intersubjective exchanges have not been carried out. Only one study to date measured endogenous oxytocin levels in newborns and reported that higher levels of oxytocin in newborns’ cerebrospinal fluid (CSF) were associated with higher levels of social engagement, including actively seeking parental social interaction for soothing and a greater interest in social interaction (33). No studies to date, however, have administered oxytocin to infants to determine its effects on social behavior, despite the fact that a more thorough understanding of oxytocin and its behavioral consequences may provide a potential tool for interventions aimed at promoting social affiliation in individuals with social impairments (11–15, 34). The necessity to fill this gap motivated the present study.Our first goal was to determine whether oxytocin influences newborn macaques’ behaviors during an interaction with a human caregiver. We predicted that oxytocin, compared with saline, would increase positive social behavior, including facial gestures [i.e., lip smacking (LPS) and tongue protrusion (TP)], visual attention to a human caregiver, and time spent in close proximity to a human caregiver (35). As adults, macaques display positive behavioral changes in response to exogenous oxytocin (2–6), as in humans (1).

Table 1.

Ethogram for 12 behaviors scored during imitation recognition