The immunopathological landscape of human pre-TCRα deficiency: From rare to common variants

We describe humans with rare biallelic loss-of-function PTCRA variants impairing pre-α T cell receptor (pre-TCRα) expression. Low circulating naive αβ T cell counts at birth persisted over time, with normal memory αβ and high γδ T cell counts. Their TCRα repertoire was biased, which suggests that noncanonical thymic differentiation pathways can rescue αβ T cell development. Only a minority of these individuals were sick, with infection, lymphoproliferation, and/or autoimmunity. We also report that 1 in 4000 individuals from the Middle East and South Asia are homozygous for a common hypomorphic PTCRA variant. They had normal circulating naive αβ T cell counts but high γδ T cell counts. Although residual pre-TCRα expression drove the differentiation of more αβ T cells, autoimmune conditions were more frequent in these patients compared with the general population.

Defining and targeting patterns of T cell dysfunction in inborn errors of immunity

Inborn errors of immunity (IEIs) are a group of more than 450 monogenic disorders that impair immune development and function. A subset of IEIs blend increased susceptibility to infection, autoimmunity, and malignancy and are known collectively as primary immune regulatory disorders (PIRDs). While many aspects of immune function are altered in PIRDs, one key impact is on T-cell function. By their nature, PIRDs provide unique insights into human T-cell signaling; alterations in individual signaling molecules tune downstream signaling pathways and effector function. Quantifying T-cell dysfunction in PIRDs and the underlying causative mechanisms is critical to identifying existing therapies and potential novel therapeutic targets to treat our rare patients and gain deeper insight into the basic mechanisms of T-cell function. Though there are many types of T-cell dysfunction, here we will focus on T-cell exhaustion, a key pathophysiological state. Exhaustion has been described in both human and mouse models of disease, where the chronic presence of antigen and inflammation (e.g., chronic infection or malignancy) induces a state of altered immune profile, transcriptional and epigenetic states, as well as impaired T-cell function. Since a subset of PIRDs amplify T-cell receptor (TCR) signaling and/or inflammatory cytokine signaling cascades, it is possible that they could induce T-cell exhaustion by genetically mimicking chronic infection. Here, we review the fundamentals of T-cell exhaustion and its possible role in IEIs in which genetic mutations mimic prolonged or amplified T-cell receptor and/or cytokine signaling. Given the potential insight from the many forms of PIRDs in understanding T-cell function and the challenges in obtaining primary cells from these rare disorders, we also discuss advances in CRISPR-Cas9 genome-editing technologies and potential applications to edit healthy donor T cells that could facilitate further study of mechanisms of immune dysfunctions in PIRDs. Editing T cells to match PIRD patient genetic variants will allow investigations into the mechanisms underpinning states of dysregulated T-cell function, including T-cell exhaustion.

Challenging systemic barriers to promote the inclusion, recruitment, and retention of URM faculty in STEM

Black/African Americans, Hispanic/Latinxs, and Native Americans remain chronically underrepresented in science, technology, engineering, and math (STEM). Values misalignment, implicit/explicit bias, and hypercompetition in the funding climate disproportionately affect underrepresented minority (URM) postdoctoral fellows transitioning into faculty positions. URM scientists must increase and be given opportunities to establish independent research programs.

Expanding mechanistic insights into the pathogenesis of idiopathic CD4+ T cell lymphocytopenia

Idiopathic CD4+ T cell lymphocytopenia (ICL) is a heterogeneous syndrome presenting with persistent CD4+ T cell lymphopenia of unknown origin, and opportunistic infections in some patients. The underlying pathogenesis and appropriate management remain understudied. In this issue of the JCI, Perez-Diez and Wong et al. assessed the prevalence of autoantibodies from the sera of 51 adult ICL patients (out of a cohort of 72). Some patients showed high levels of IgG and IgM autoantibodies against numerous autoantigens, and some autoantibodies were specific for lymphocytes. The researchers implicate these autoantibodies as a possible pathogenic mechanism responsible for the reduction in circulating CD4+ T cells. This study goes beyond defining a mechanism in a complex, poorly defined disease; it also brings a renewed focus on ICL that will likely result in improved diagnostic evaluation and treatment.

Developing an information system to support the pursuit of decentralization. The perspective of Cearà State in Brazil

Discusses the national health information system in Brazil which, until very recently, consisted of two main structures of health services with a dichotomy between curative and preventive health care acting in a vertical manner. The autonomy of health authorities and specialized structures created numerous independent health information systems with different methods of data collection. Although the issues of decentralization and a unified health system had been agreed on in 1963, they had not been implemented until the new health policy reform was lunched in 1988. The reform was based on the strengthening of primary health care at national level and accelerating decentralization of health systems. However, in spite of strong political will the new health managers at local level are lacking essential information, data and instruments that only a decentralized health management information system can provide. Based on a study conducted in the Cearà State of the north east of Brazil, explores how the present health information system can support the process of decentralization.

[Familial incidence of intracranial aneurysms]

São relatados 4 casos de aneurismas cerebrais que ocorreram em duas famílias. A etiologia dos aneurismas intracranianos é discutida, principalmente no que se refere à ocorrência de aneurismas dentro de uma mesma família. A literatura pertinente é revista e são tecidos comentários sobre a validade estatística dessa associação.