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Summary: The immune system plays a critical role in protecting the host against infection but is subject to numerous levels of control that are necessary to prevent pathological, tissue-damaging responses. Inappropriate inflammatory immune responses to self-antigens, innocuous commensal microorganisms, or environmental antigens can lead to chronic, debilitating, and degenerative diseases. Regulatory T cells have an essential, non-redundant, and dominant function in preventing pathological immune responses, as shown by the development of systemic fatal autoimmunity in humans and animals with a genetic deficiency in regulatory T cells. In addition to controlling immune responses, there is a growing understanding that regulatory T cells also contribute directly to tissue homeostasis by promoting tissue regeneration and repair. For these reasons, the prospect of enhancing regulatory T-cell numbers and/or function in patients represents an appealing therapeutic opportunity with potential applications in many diseases, including some where the pathological role of the immune system has only recently been recognized. Approaches to enhance regulatory T cells are now starting to be explored in clinical studies in humans. This review series brings together papers highlighting the Treg-enhancing approaches that are most advanced clinically and examples of therapeutic opportunities based on our growing understanding of regulatory T-cell functions. [ABSTRACT FROM AUTHOR]

Understanding the T-cell response to SARS-CoV-2 is key in patients who lack antibody production. We demonstrate the applicability of a functional assay to measure the T-cell response in a cohort of patients with immunodeficiency. T-cell responses to COVID are now linked to improved outcomes. This paper demonstrates a method to robustly test responses for routine diagnostic use in healthy controls and those unable to make a detectable antibody response due to underlying immune deficiency (primary or acquired). [ABSTRACT FROM AUTHOR]

Summary: The factors responsible for the spectrum of coronavirus 19 (COVID‐19) disease severity and the genesis and nature of protective immunity against COVID‐19 remain elusive. Multiple studies have investigated the immune responses to COVID‐19 in various populations, including those without evidence of COVID‐19 infection. Information regarding innate and adaptive immune responses to the novel severe respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has evolved rapidly. Data are accumulating defining disease phenotypes that aid in rational and informed development of new therapeutic approaches for the treatment of patients infected with SARS‐CoV‐2 and the development of novel vaccines. In this paper, data on important innate immune responses are summarized, including cytokines, specifically interleukin (IL)‐6 and complement, and potential treatments are explored. Adaptive immune responses and derivative therapeutics such as monoclonal antibodies directed at spike proteins are also examined. Finally, data on real‐time assessments of adaptive immune responses are explored, which include CD4+/CD8+ T cells, natural killer (NK) T cells, memory B cells and T follicular cells with specificities for COVID‐19 peptides in infected and normal individuals. Data of two novel vaccines have been released, both showing > 95% efficacy in preventing SARS‐CoV‐2 infection. Analysis of humoral and cellular responses to the vaccines will determine the robustness and durability of protection. In addition, long‐term assessment of SARS‐CoV‐2 memory B and T cell‐mediated immune responses in patients recovering from an infection or those with cross‐reactive immunological memory will help to define risk for future SARS‐CoV infections. Finally, patients recovering from SARS‐CoV‐2 infection may experience prolonged immune activation probably due to T cell exhaustion. This will be an important new frontier for study. This review summarizes published data on the relevant innate and adaptive immune responses to SARS‐CoV‐2. Data characterizing innate and adaptive immune responses have rapidly led to informed therapeutic interventions, including vaccine development and recognition of dysfunctional immune responses that are likely responsible for post‐COVID‐19 autoimmunity. [ABSTRACT FROM AUTHOR]

Summary: Lung disease due to nontuberculous mycobacteria (NTM) occurs with disproportionate frequency in postmenopausal women with a unique phenotype and without clinically apparent predisposing factors. Dubbed 'Lady Windermere syndrome', the phenotype includes low body mass index (BMI), tall stature and higher than normal prevalence of scoliosis, pectus excavatum and mitral valve prolapse. Although the pathomechanism for susceptibility to NTM lung disease in these patients remains uncertain, it is likely to be multi‐factorial. A role for the immunomodulatory consequences of oestrogen deficiency and altered adipokine production has been postulated. Altered levels of adipokines and dehydroepiandrosterone have been demonstrated in patients with NTM lung disease. Case reports of NTM lung disease in patients with hypopituitarism support the possibility that altered endocrine function influences disease susceptibility. This paper catalogues the evidence for immunomodulatory consequences of predicted endocrine changes in Lady Windermere syndrome, with emphasis on the immune response to NTM. Collectively, the data warrant further exploration of an endocrine link to disease susceptibility in Lady Windermere syndrome. Lady Windermere syndrome is a phenotype of nontuberculous mycobacterial lung disease characterized by female sex, postmenopausal status and slender body habitus. This review article explores potential modulation of anti‐mycobacterial immunity by hormone changes as a mediator of disease susceptibility in this syndrome. [ABSTRACT FROM AUTHOR]