BRAF inhibition is associated with increased clonality in tumor-infiltrating lymphocytes

There have been significant advances with regard to BRAF-targeted therapies against metastatic melanoma. However, the majority of patients receiving BRAF inhibitors (BRAFi) manifest disease progression within a year. We have recently shown that melanoma patients treated with BRAFi exhibit an increase in melanoma-associated antigens and in CD8+ tumor-infiltrating lymphocytes in response to therapy. To characterize such a T-cell infiltrate, we analyzed the complementarity-determining region 3 (CDR3) of rearranged T-cell receptor (TCR) β chain-coding genes in tumor biopsies obtained before the initiation of BRAFi and 10–14 d later. We observed an increase in the clonality of tumor-infiltrating lymphocytes in 7 of 8 patients receiving BRAFi, with a statistically significant 21% aggregate increase in clonality. Over 80% of individual T-cell clones detected after initiation of BRAFi treatment were new clones. Interestingly, the comparison of tumor infiltrates with clinical responses revealed that patients who had a high proportion of pre-existing dominant clones after the administration of BRAFi responded better to therapy than patients who had a low proportion of such pre-existing dominant clones following BRAFi. These data suggest that although the inhibition of BRAF in melanoma patients results in tumor infiltration by new lymphocytes, the response to treatment appears to be related to the presence of a pre-existing population of tumor-infiltrating T-cell clones

Clonal Growth of Dermal Papilla Cells in Hydrogels Reveals Intrinsic Differences between Sox2-Positive and -Negative Cells In Vitro and In Vivo

In neonatal mouse skin, two types of dermal papilla (DP) are distinguished by Sox2 expression: CD133+Sox2+ DP are associated with guard/awl/auchene hairs, whereas CD133+Sox2− DP are associated with zigzag (ZZ) hairs. We describe a three-dimensional hydrogel culture system that supports clonal growth of CD133+Sox2+, CD133+Sox2−, and CD133−Sox2− (non-DP) neonatal dermal cells. All three cell populations formed spheres that expressed the DP markers alkaline phosphatase, α8 integrin, and CD133. Nevertheless, spheres formed by CD133− cells did not efficiently support hair follicle formation in skin reconstitution assays. In the presence of freshly isolated P2 dermal cells, CD133+Sox2+ and CD133+Sox2− spheres contributed to the DP of both AA and ZZ hairs. Hair type did not correlate with sphere size. Sox2 expression was maintained in culture, but not induced significantly in Sox2− cells in vitro or in vivo, suggesting that Sox2+ cells are a distinct cellular lineage. Although Sox2+ cells were least efficient at forming spheres, they had the greatest ability to contribute to DP and non-DP dermis in reconstituted skin. As the culture system supports clonal growth of DP cells and maintenance of distinct DP cell types, it will be useful for further analysis of intrinsic and extrinsic signals controlling DP function

Neurodevelopmental disorders in children aged 2-9 years: Population-based burden estimates across five regions in India.

BACKGROUND: Neurodevelopmental disorders (NDDs) compromise the development and attainment of full social and economic potential at individual, family, community, and country levels. Paucity of data on NDDs slows down policy and programmatic action in most developing countries despite perceived high burden. METHODS AND FINDINGS: We assessed 3,964 children (with almost equal number of boys and girls distributed in 2-<6 and 6-9 year age categories) identified from five geographically diverse populations in India using cluster sampling technique (probability proportionate to population size). These were from the North-Central, i.e., Palwal (N = 998; all rural, 16.4% non-Hindu, 25.3% from scheduled caste/tribe [SC-ST] [these are considered underserved communities who are eligible for affirmative action]); North, i.e., Kangra (N = 997; 91.6% rural, 3.7% non-Hindu, 25.3% SC-ST); East, i.e., Dhenkanal (N = 981; 89.8% rural, 1.2% non-Hindu, 38.0% SC-ST); South, i.e., Hyderabad (N = 495; all urban, 25.7% non-Hindu, 27.3% SC-ST) and West, i.e., North Goa (N = 493; 68.0% rural, 11.4% non-Hindu, 18.5% SC-ST). All children were assessed for vision impairment (VI), epilepsy (Epi), neuromotor impairments including cerebral palsy (NMI-CP), hearing impairment (HI), speech and language disorders, autism spectrum disorders (ASDs), and intellectual disability (ID). Furthermore, 6-9-year-old children were also assessed for attention deficit hyperactivity disorder (ADHD) and learning disorders (LDs). We standardized sample characteristics as per Census of India 2011 to arrive at district level and all-sites-pooled estimates. Site-specific prevalence of any of seven NDDs in 2-<6 year olds ranged from 2.9% (95% CI 1.6-5.5) to 18.7% (95% CI 14.7-23.6), and for any of nine NDDs in the 6-9-year-old children, from 6.5% (95% CI 4.6-9.1) to 18.5% (95% CI 15.3-22.3). Two or more NDDs were present in 0.4% (95% CI 0.1-1.7) to 4.3% (95% CI 2.2-8.2) in the younger age category and 0.7% (95% CI 0.2-2.0) to 5.3% (95% CI 3.3-8.2) in the older age category. All-site-pooled estimates for NDDs were 9.2% (95% CI 7.5-11.2) and 13.6% (95% CI 11.3-16.2) in children of 2-<6 and 6-9 year age categories, respectively, without significant difference according to gender, rural/urban residence, or religion; almost one-fifth of these children had more than one NDD. The pooled estimates for prevalence increased by up to three percentage points when these were adjusted for national rates of stunting or low birth weight (LBW). HI, ID, speech and language disorders, Epi, and LDs were the common NDDs across sites. Upon risk modelling, noninstitutional delivery, history of perinatal asphyxia, neonatal illness, postnatal neurological/brain infections, stunting, LBW/prematurity, and older age category (6-9 year) were significantly associated with NDDs. The study sample was underrepresentative of stunting and LBW and had a 15.6% refusal. These factors could be contributing to underestimation of the true NDD burden in our population. CONCLUSIONS: The study identifies NDDs in children aged 2-9 years as a significant public health burden for India. HI was higher than and ASD prevalence comparable to the published global literature. Most risk factors of NDDs were modifiable and amenable to public health interventions

Role of the programmed death-one pathway in the tumor microenvironment

Thesis: Ph. D. in Medical Engineering and Medical Physics, Harvard-MIT Program in Health Sciences and Technology, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 164-176).The immune system has proven valuable in the fight against cancer. Therapies that unleash a T cell response against tumors have led to durable remissions in multiple cancers. Specifically, antibodies blocking the programmed death (PD)-1 pathway have been approved for the treatment of metastatic melanoma, non-small cell lung cancer, and renal cell carcinoma, amongst others. However, only a limited number of patients respond to these therapies. The field is now trying to determine combination strategies and biomarkers to extend the benefits of these therapies to additional patients in a rationale manner. A fundamental challenge towards this goal is that the cellular and molecular mechanisms underlying the efficacy of PD-1 pathway blockade are not well understood. In this thesis, we dissected the role of PD-1 and its ligands on multiple cell types in the tumor microenvironment. PD-1 is a receptor expressed on T cells upon activation, amongst other cells. Its ligands, PD-L1 and PD-L2, can be expressed on many cell types, including tumor cells. In the first section, we show that PD-1 pathway blockade can effectively combine with another therapy targeted at tumor cells themselves, BRAF inhibitors. This work provided support for ongoing clinical trials. In the second section, we show that tumor cells can protect themselves from immune eradication by expressing PD-L1, which directly suppresses the cytotoxicity of CD8* T cells. This establishes a key mechanism by which the PD-1 pathway prevents effective antitumor immunity. In the third section, we show that the inhibition of CD8* T cell cytotoxicity through PD-1 signaling is due in part to cell-intrinsic and cell-extrinsic suppression of T cell metabolism. Removing the inhibitory PD-1 signal on a fraction of cells enhances their metabolic state and allows them to become more cytotoxic. In turn, this creates a tumor microenvironment that allows additional CD8* T cells to become more functional. We show that pharmacologic agents that mimic these effects of metabolism can enhance CD8* T cell cytotoxicity. These mechanistic insights will assist in developing cancer therapies that combine PD-1 blockade with other approaches to broaden the benefit of PD-1 immunotherapy.by Vikram R. Juneja.Ph. D. in Medical Engineering and Medical Physic

“I was Confused … and Still am” Barriers Impacting the Help-Seeking Pathway for an Autism Diagnosis in Urban North India: A Mixed Methods Study

Timely recognition of autism in children is integral to improve developmental outcomes. This study used mixed-methods (84 case-registers and 20 in-depth interviews with caregivers of children with a diagnosis of autism) to explore the extent to which the nature of parental concerns and prior knowledge of developmental disorders impact the time between symptom recognition and autism diagnosis, and the contextual family, societal and health-system related factors that impede the autism help-seeking pathway. Lack of awareness of age-appropriate child developmental milestones, apparent amongst the community and health professionals, contributed to a 1.5-year delay between parental concerns and autism diagnosis. Recommendations to shorten this help-seeking pathway include harnessing the potential of non-specialist workers to increase awareness and enable developmental monitoring of young children through scalable tools. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10803-021-05047-z

PD-L1 on tumor cells is sufficient for immune evasion in immunogenic tumors and inhibits CD8 T cell cytotoxicity

It is unclear whether PD-L1 on tumor cells is sufficient for tumor immune evasion or simply correlates with an inflamed tumor microenvironment. We used three mouse tumor models sensitive to PD-1 blockade to evaluate the significance of PD-L1 on tumor versus nontumor cells. PD-L1 on nontumor cells is critical for inhibiting antitumor immunity in B16 melanoma and a genetically engineered melanoma. In contrast, PD-L1 on MC38 colorectal adenocarcinoma cells is sufficient to suppress antitumor immunity, as deletion of PD-L1 on highly immunogenic MC38 tumor cells allows effective antitumor immunity. MC38-derived PD-L1 potently inhibited CD8+ T cell cytotoxicity. Wild-type MC38 cells outcompeted PD-L1–deleted MC38 cells in vivo, demonstrating tumor PD-L1 confers a selective advantage. Thus, both tumor- and host-derived PD-L1 can play critical roles in immunosuppression. Differences in tumor immunogenicity appear to underlie their relative importance. Our findings establish reduced cytotoxicity as a key mechanism by which tumor PD-L1 suppresses antitumor immunity and demonstrate that tumor PD-L1 is not just a marker of suppressed antitumor immunity

Locked down-locked in: experiences of families of young children with autism spectrum disorders in Delhi, India

Introduction: The onset of the COVID-19 pandemic and subsequent lockdowns in March 2020 disrupted the lives of families across India. The lockdown related restrictions brought forth a multitude of challenges including loss of employment, social isolation, school closures and financial burdens. Specifically, it also resulted in the restriction of health-care services for children with neurodevelopmental disabilities.Methods: This qualitative study was conducted as a part of a larger trial in India to understand the experiences of families of young children with autism during the pandemic. In-depth interviews were carried out with 14 caregivers residing in New Delhi, India.Results: Our findings identified pandemic and lockdown’s universal impacts on family life and financial stability stemming from job loss, business closure, and salary deductions, affecting quality of life of families. Furthermore, COVID-19 pandemic’s impact on autistic children was evident through limited access to essential services and financial challenges related service interruptions even after resumption of services. The lockdown’s novelty also affected children’s behavior, with both challenging behavioral changes and positive impacts. Primary caregivers, predominantly mothers, assumed additional responsibilities in household tasks, schooling, and therapy administration. While some these experiences were universally experienced, a few of these improved outcomes for autistic children. Despite challenges, parents expressed gratitude for their family’s safety and well-being during the difficult time.Discussions: These findings inform service provision for vulnerable families and offer implications for designing interventions such as credit schemes for families, guidance and resources for establishing and maintaining routines of children with autism, adopting flexible and adaptable approaches to service delivery, and special provisions for children with autism to be able to maintain their routines outside of home. Furthermore, the study highlights the need for comprehensive support, including educational resources and stress management counselling to empower parents in supporting essential care and routines for their children during such unprecedented times

Deletion of CTLA-4 on regulatory T cells during adulthood leads to resistance to autoimmunity

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential negative regulator of T cell responses. Germline Ctla4 deficiency is lethal, making investigation of the function of CTLA-4 on mature T cells challenging. To elucidate the function of CTLA-4 on mature T cells, we have conditionally ablated Ctla4 in adult mice. We show that, in contrast to germline knockout mice, deletion of Ctla4 during adulthood does not precipitate systemic autoimmunity, but surprisingly confers protection from experimental autoimmune encephalomyelitis (EAE) and does not lead to increased resistance to MC38 tumors. Deletion of Ctla4 during adulthood was accompanied by activation and expansion of both conventional CD4+Foxp3− (T conv) and regulatory Foxp3+ (T reg cells) T cell subsets; however, deletion of CTLA-4 on T reg cells was necessary and sufficient for protection from EAE. CTLA-4 deleted T reg cells remained functionally suppressive. Deletion of Ctla4 on T reg cells alone or on all adult T cells led to major changes in the Ctla4 sufficient T conv cell compartment, including up-regulation of immunoinhibitory molecules IL-10, LAG-3 and PD-1, thereby providing a compensatory immunosuppressive mechanism. Collectively, our findings point to a profound role for CTLA-4 on T reg cells in limiting their peripheral expansion and activation, thereby regulating the phenotype and function of T conv cells

Development of a cost of illness inventory questionnaire for children with autism spectrum disorder in South Asia

BACKGROUND: The economic burden of autism is substantial and includes a range of costs, including healthcare, education, productivity losses, informal care and respite care, among others. In India, approximately, 2 million children aged 2-9 years have autism. Given the likely substantial burden of illness and the need to identify effective and cost-effective interventions, this research aimed to produce a comprehensive cost of illness inventory (COII) suitable for children with autism in South Asia (India) to support future research. METHODS: A structured and iterative design process was followed to create the COII, including literature reviews, interviews with caregivers, pilot testing and translation. Across the development of the COII, thirty-two families were involved in the design and piloting of the tool. The COII was forward translated (from English to Hindi) and back translated. Each stage of the process of development of the COII resulted in the further refinement of the tool. RESULTS: Domains covered in the final COII include education, childcare, relocation, healthcare contacts (outpatient, inpatient, medical emergencies, investigations and medication), religious retreats and rituals, specialist equipment, workshops and training, special diet, support and care, certification, occupational adjustments and government rebates/schemes. Administration and completion of the COII determined it to be feasible to complete in 35 minutes by qualified and trained researchers. The final COII is hosted by REDCap Cloud and is a bilingual instrument (Hindi and English). CONCLUSIONS: The COII was developed using experiences gathered from an iterative process in a metropolitan area within the context of one low- and middle-income country (LMIC) setting, India. Compared to COII tools used for children with autism in high-income country settings, additional domains were required, such as complimentary medication (e.g. religious retreats and homeopathy). The COII will allow future research to quantify the cost of illness of autism in India from a broad perspective and will support relevant economic evaluations. Understanding the process of developing the questionnaire will help researchers working in LMICs needing to adapt the current COII or developing similar questionnaires