Heterozygous FOXN1 Variants Cause Low TRECs and Severe T Cell Lymphopenia, Revealing a Crucial Role of FOXN1 in Supporting Early Thymopoiesis.

FOXN1 is the master regulatory gene of thymic epithelium development. FOXN1 deficiency leads to thymic aplasia, alopecia, and nail dystrophy, accounting for the nude/severe combined immunodeficiency (nu/SCID) phenotype in humans and mice. We identified several newborns with low levels of T cell receptor excision circles (TRECs) and T cell lymphopenia at birth, who carried heterozygous loss-of-function FOXN1 variants. Longitudinal analysis showed persistent T cell lymphopenia during infancy, often associated with nail dystrophy. Adult individuals with heterozygous FOXN1 variants had in most cases normal CD4+ but lower than normal CD8+ cell counts. We hypothesized a FOXN1 gene dosage effect on the function of thymic epithelial cells (TECs) and thymopoiesis and postulated that these effects would be more prominent early in life. To test this hypothesis, we analyzed TEC subset frequency and phenotype, early thymic progenitor (ETP) cell count, and expression of FOXN1 target genes (Ccl25, Cxcl12, Dll4, Scf, Psmb11, Prss16, and Cd83) in Foxn1nu/+ (nu/+) mice and age-matched wild-type (+/+) littermate controls. Both the frequency and the absolute count of ETP were significantly reduced in nu/+ mice up to 3 weeks of age. Analysis of the TEC compartment showed reduced expression of FOXN1 target genes and delayed maturation of the medullary TEC compartment in nu/+ mice. These observations establish a FOXN1 gene dosage effect on thymic function and identify FOXN1 haploinsufficiency as an important genetic determinant of T cell lymphopenia at birth.

Extensive Bilateral Cervicofacial Lymphadenitis Caused by Atypical Mycobacterium.

Non-tuberculous mycobacterial (NTM) lymphadenitis typically presents as a unilateral, non-tender, slowly enlarging cervical, submandibular, or pre-auricular lymph node in children. Disseminated NTM infection is most often seen in immunocompromised children. Here, we present an unusual case of extensive bilateral cervical and retropharyngeal lymphadenitis caused by Mycobacterium Avium Complex (MAC) in an ostensibly immunocompetent pediatric patient.

Researcher Views of Barriers to Clinical and Translational Research in a Statewide Program.

The Tracking and Evaluation Core of Rhode Island Advance-CTR conducted an online needs assessment survey at the program's inception in 2016 and again in 2021. Now dealing with well-established support systems provided by the grant, we were particularly interested in how the perceived needs of the research community in Rhode Island might have changed over five years. Specifically, what barriers have been reduced or eliminated and which have persisted or increased? How do those barriers vary by demographic status and what implications do those differences have for the CTR? An online survey was completed by 199 researchers, who reported the extent to which they perceived the lack of access to a range of research supports as a barrier to conducting research at their institution. Overall, researchers indicated statistically significant changes from 2016 to 2021 such that a lack of pilot project funding and proposal development support had decreased as barriers, while space for research, and advice on commercial development, had increased. Statistically significant differences in the salience of particular barriers by some demographic variables were also noted and the results of this study suggest Centers for Clinical and Translational Research can have salutary effects on the research paradigm within their partnering institutions in a relatively short time.

TLR9 ligand sequestration by chemokine CXCL4 negatively affects central B cell tolerance.

Central B cell tolerance is believed to be regulated by B cell receptor signaling induced by the recognition of self-antigens in immature B cells. Using humanized mice with defective MyD88, TLR7, or TLR9 expression, we demonstrate that TLR9/MYD88 are required for central B cell tolerance and the removal of developing autoreactive clones. We also show that CXCL4, a chemokine involved in systemic sclerosis (SSc), abrogates TLR9 function in B cells by sequestering TLR9 ligands away from the endosomal compartments where this receptor resides. The in vivo production of CXCL4 thereby impedes both TLR9 responses in B cells and the establishment of central B cell tolerance. We conclude that TLR9 plays an essential early tolerogenic function required for the establishment of central B cell tolerance and that correcting defective TLR9 function in B cells from SSc patients may represent a novel therapeutic strategy to restore B cell tolerance.

Evaluating systemic changes to support clinical and translational health research.

In evaluation research, "programs" are often conceptualized as clearly bounded, narrow in scope, focused on specific outcomes, using a well-defined linear causal model, and hence, suitable for standard evaluation methods. The evaluation work reported here was carried out in a more challenging context, where large, complex, interwoven systems were targets for change as a means to influence a diffuse array of outcomes. Our evaluation of an NIH-funded program to improve statewide infrastructure for clinical and translational health research ("Advance-CTR") used qualitative data provided by investigators who used the program's services, were funded awardees, or were members of an internal advisory committee (leadership representatives from partnering institutions). We examined perceived barriers to systemic changes to enhance research, as well as how systems have changed due to the Rhode Island Advance-CTR program's efforts, to what degree, and with what effects. Using the causal logic of our program to connect these more distal systemic outcomes to the services and components of Advance-CTR, we discuss the effects this program has had on researchers and their environments, contributing to the development of sustainable programs of research that ultimately improve the health and well-being of our state's residents.

Influence of age and nature of primary infection on varicella-zoster virus-specific cell-mediated immune responses.

BACKGROUND: Varicella-zoster virus (VZV)-specific cell-mediated immunity is important for protection against VZV disease. We studied the relationship between VZV cell-mediated immunity and age after varicella or VZV vaccination in healthy and human immunodeficiency virus (HIV)-infected individuals. METHODS: VZV responder cell frequency (RCF) determinations from 752 healthy and 200 HIV-infected subjects were used to identify group-specific regression curves on age. RESULTS: In healthy individuals with past varicella, VZV RCF peaked at 34 years of age. Similarly, VZV-RCF after varicella vaccine increased with age in subjects aged <1 to 43 years. In subjects aged 61-90 years, VZV RCF after zoster vaccine decreased with age. HIV-infected children had lower VZV RCF estimates than HIV-infected adults. In both groups, VZV RCF results were low and constant over age. Varicella vaccination of HIV-infected children with CD4 levels 20% generated VZV RCF values higher than wild-type infection and comparable to vaccine-induced responses of healthy children. CONCLUSIONS: In immunocompetent individuals with prior varicella, VZV RCF peaked in early adulthood. Administration of varicella vaccine to HIV-infected or uninfected individuals aged >5 years generated VZV RCF values similar to those of immunocompetent individuals with immunity induced by wild-type infection. A zoster vaccine increased the VZV RCF of elderly adults aged <75 years to values higher than peak values induced by wild-type infection.

Improving the quality and quantity of clinical and translational research statewide: An application of group concept mapping.

INTRODUCTION: Advance Clinical and Translational Research (Advance-CTR) serves as a central hub to support and educate clinical and translational researchers in Rhode Island. Understanding barriers to clinical research in the state is the key to setting project aims and priorities. METHODS: We implemented a Group Concept Mapping exercise to characterize the views of researchers and administrators regarding how to increase the quality and quantity of clinical and translational research in their settings. Participants generated ideas in response to this prompt and rated each unique idea in terms of how important it was and feasible it seemed to them. RESULTS: Participants generated 78 unique ideas, from which 9 key themes emerged (e.g., Building connections between researchers). Items rated highest in perceived importance and feasibility included providing seed grants for pilot projects, connecting researchers with common interests and networking opportunities. Implications of results are discussed. CONCLUSIONS: The Group Concept Mapping exercise enabled our project leadership to better understand stakeholder-perceived priorities and to act on ideas and aims most relevant to researchers in the state. This method is well suited to translational research enterprises beyond Rhode Island when a participatory evaluation stance is desired.

Disseminated and Congenital Toxoplasmosis in a Mother and Child With Activated PI3-Kinase δ Syndrome Type 2 (APDS2): Case Report and a Literature Review of Toxoplasma Infections in Primary Immunodeficiencies.

Phosphoinositide 3-kinase (PI3K) plays an integral role in lymphocyte function. Mutations in PIK3CD and PIK3R1, encoding the PI3K p110δ and p85α subunits, respectively, cause increased PI3K activity and result in immunodeficiency with immune dysregulation. We describe here the first cases of disseminated and congenital toxoplasmosis in a mother and child who share a pathogenic mutation in PIK3R1 and review the mechanisms underlying susceptibility to severe Toxoplasma gondii infection in activated PI3Kδ syndrome (APDS) and in other forms of primary immunodeficiency.

Clinical and Translational Research in Rhode Island: Results of a Needs Assessment Survey.

The Advance-Clinical and Translational Research (CTR) program was established in Rhode Island in May of 2016 with an IDeA Program Infrastructure award to collaborating institutions: Brown University, the University of Rhode Island, with the Lifespan, Care New England and Providence VA Medical Center healthcare institutions and the Rhode Island Quality Institute. To support programmatic planning, the Tracking and Evaluation Key Component Activity (KCA) of Advance-CTR developed and implemented a needs assessment survey to identify the obstacles to clinical and translational research at the participating institutions. We describe the methods used and the responses, which identified needs for study design and data analysis support. Support for project development, pilot funding and grants administration showed significant variation, depending on the affiliation of the respondent. The results of the survey are discussed in the context of Rhode Island's significant opportunities to support and develop the capabilities of scientists who engage in translational research. [Full article available at http://rimed.org/rimedicaljournal-2018-02.asp].

Natural Killer Cells from Patients with Recombinase-Activating Gene and Non-Homologous End Joining Gene Defects Comprise a Higher Frequency of CD56bright NKG2A+++ Cells, and Yet Display Increased Degranulation and Higher Perforin Content.

Mutations of the recombinase-activating genes 1 and 2 (RAG1 and RAG2) in humans are associated with a broad range of phenotypes. For patients with severe clinical presentation, hematopoietic stem cell transplantation (HSCT) represents the only curative treatment; however, high rates of graft failure and incomplete immune reconstitution have been observed, especially after unconditioned haploidentical transplantation. Studies in mice have shown that Rag-/- natural killer (NK) cells have a mature phenotype, reduced fitness, and increased cytotoxicity. We aimed to analyze NK cell phenotype and function in patients with mutations in RAG and in non-homologous end joining (NHEJ) genes. Here, we provide evidence that NK cells from these patients have an immature phenotype, with significant expansion of CD56bright CD16-/int CD57- cells, yet increased degranulation and high perforin content. Correlation was observed between in vitro recombinase activity of the mutant proteins, NK cell abnormalities, and in vivo clinical phenotype. Addition of serotherapy in the conditioning regimen, with the aim of depleting the autologous NK cell compartment, may be important to facilitate engraftment and immune reconstitution in patients with RAG and NHEJ defects treated by HSCT.

Corrigendum: Natural Killer Cells from Patients with Recombinase-Activating Gene and Non-Homologous End Joining Gene Defects Comprise a Higher Frequency of CD56bright NKG2A+++ Cells, and Yet Display Increased Degranulation and Higher Perforin Content.

[This corrects the article on p. 798 in vol. 8, PMID: 28769923.].

Abnormal TREC-Based Newborn Screening Test in a Premature Neonate with Massive Perivillous Fibrin Deposition of the Placenta.

Severe combined immunodeficiency (SCID), a primary immunodeficiency arising from variable defects in lymphocyte development and survival, is characterized by significant deficiency of thymus derived (T-) lymphocytes and variable defects in the B-lymphocyte population. Newborn screening for SCID is based on detection of low numbers of T-cell receptor excision circles (TRECs) by real time quantitative PCR (RT-qPCR). This screening allows for early identification of individuals with SCID and other disorders characterized by T-lymphopenia. Higher rates of abnormal screens are commonly seen in premature and critically ill neonates, often representing false positives. It is possible that many abnormal screens seen in these populations are result of conditions that are characterized by systemic inflammation or stress, possibly in the context of stress-induced thymic involution. We present a case of a male infant delivered at 27 weeks, 6 days of gestation, with severe intrauterine growth restriction who had an abnormal TREC screen and a massive perivillous fibrin deposition (MPFD) of the placenta. This association has not been reported previously. We are raising the awareness to the fact that conditions, such as MPFD, that can create adverse intrauterine environment are capable of causing severe stress-induced thymic involution of the fetus which can present with abnormal TREC results on newborn screening.

Cytokine and immunosuppressive therapies of type 1 diabetes mellitus.

In this article, the authors covered a number of issues that affect how researchers approach prevention of diabetes. The focus has been the use of cytokines and immunosuppressive therapies. The historical understanding of cytokine and immunosuppressive approaches, new developments in using these agents in humans, and the issues involved in designing diabetes prevention trials were reviewed. Although progress at times appears slow, the current research activities predict new developments in the next few years that may improve the understanding of the progression of diabetes and possible ways to intervene.

The role of the National Center for Research Resources at the National Institutes of Health: infrastructure to forge a new road for lymphatic biology and therapeutics.

Lymphatic research has infrastructure needs ranging from the nursing support provided by General Clinical Research Centers to training grants for future clinician investigators. Both have high priority in the activities currently funded by the Division of Clinical Research at NCRR. Further into the future, the therapeutic development networks and embryonic stem cells resources that are currently being developed should seem equally to have been essential resources.

Making clinical research a robust career path.

This commentary relates to three articles in this issue of Academic Medicine, which address the vision of the National Institutes of Health (NIH) for clinical and translational research. Those articles encompass the first successful Clinical and Translational Science Award applicants' stated aims for their programs, the success of a Harvard training program, and the case for exposing medical students to research experiences. The positive recommendations each makes are timely and give the author an opportunity to draw attention to related NIH education and outreach programs. Meeting the NIH's mission "to extend healthy life and reduce the burdens of illness and disability" will need a coordinated approach to ensure that health care workers are aware of the importance of research-and that clinical researchers see a secure, research-related career structure in academic health centers.