TCR+/BCR+ dual-expressing cells and their associated public BCR clonotype are not enriched in type 1 diabetes.

Ahmed and colleagues recently described a novel hybrid lymphocyte expressing both a B and T cell receptor, termed double expresser (DE) cells. DE cells in blood of type 1 diabetes (T1D) subjects were present at increased numbers and enriched for a public B cell clonotype. Here, we attempted to reproduce these findings. While we could identify DE cells by flow cytometry, we found no association between DE cell frequency and T1D status. We were unable to identify the reported public B cell clone, or any similar clone, in bulk B cells or sorted DE cells from T1D subjects or controls. We also did not observe increased usage of the public clone VH or DH genes in B cells or in sorted DE cells. Taken together, our findings suggest that DE cells and their alleged public clonotype are not enriched in T1D. This Matters Arising paper is in response to Ahmed et al. (2019), published in Cell. See also the response by Ahmed et al. (2021), published in this issue.

Lack of recall response to Tax in ATL and HAM/TSP patients but not in asymptomatic carriers of human T-cell leukemia virus type 1.

PURPOSE & METHODS: The immunopathogenic mechanisms responsible for debilitating neurodegenerative and oncologic diseases associated with human T-cell leukemia virus type 1 (HTLV-1) are not fully understood. Quality of cytotoxic T lymphocytes (CTLs) is being increasingly associated with the outcome of persistent HTLV-1 infection. In this respect, a patient cohort (from HTLV-1 endemic region) consisting of seronegative controls (controls), asymptomatic carriers (ACs), and patients with adult T-cell leukemia (ATL) or HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) was analyzed for CD8(+) T cells polyfunctionality in response to the viral antigen Tax. RESULTS: Compared to ACs, ATL and HAM/TSP patients had lower frequency and polyfunctionality of CTLs in response to Tax suggesting dysfunction of CD8(+) T cells in these individuals. As an underlying mechanism, programmed death-1 (PD-1) receptor was found to be highly unregulated in Tax-responsive as well as total CD8(+) T cells from ATL and HAM/TSP but not from ACs and directly correlated with the lack of polyfunctionality in these individuals. Further, PD-1 expression showed a direct whereas MIP-1α expression had an indirect correlation with the proviral load providing new insights about the immunopathogenesis of HTLV-associated diseases. Additionally, we identified key cytokine signatures defining the immune activation status of clinical samples by the luminex assay. CONCLUSIONS: Collectively, our findings suggest that reconstitution of fully functional CTLs, stimulation of MIP-1α expression, and/or blockade of the PD-1 pathway are potential approaches for immunotherapy / therapeutic vaccine against HTLV-mediated diseases.

Perforin and IL-2 upregulation define qualitative differences among highly functional virus-specific human CD8 T cells.

The prevailing paradigm of T lymphocyte control of viral replication is that the protective capacity of virus-specific CD8(+) T cells is directly proportional to the number of functions they can perform, with IL-2 production capacity considered critical. Having recently defined rapid perforin upregulation as a novel effector function of antigen-specific CD8(+) T cells, here we sought to determine whether new perforin production is a component of polyfunctional CD8(+) T cell responses that contributes to the control of several human viral infections: cytomegalovirus (CMV), Epstein-Barr virus (EBV), influenza (flu), and adenovirus (Ad). We stimulated normal human donor PBMC with synthetic peptides whose amino acid sequences correspond to defined CTL epitopes in the aforementioned viruses, and then used polychromatic flow cytometry to measure the functional capacity and the phenotype of the responding CD8(+) T cells. While EBV and flu-specific CD8(+) T cells rarely upregulate perforin, CMV-specific cells often do and Ad stimulates an exceptionally strong perforin response. The differential propensity of CD8(+) T cells to produce either IL-2 or perforin is in part related to levels of CD28 and the transcription factor T-bet, as CD8(+) T cells that rapidly upregulate perforin harbor high levels of T-bet and those producing IL-2 express high amounts of CD28. Thus, "polyfunctional" profiling of antigen-specific CD8(+) T cells must not be limited to simply the number of functions the cell can perform, or one particular memory phenotype, but should actually define which combinations of memory markers and functions are relevant in each pathogenic context.

Rapid onset of iatrogenic adrenal insufficiency in a patient with cystic fibrosis-related liver disease treated with inhaled corticosteroids and a moderate CYP3A4 inhibitor.

OBJECTIVE: To report the rapid onset of adrenal insufficiency and subsequent development of Cushing syndrome precipitated by a CYP3A4-mediated drug-drug interaction that may have been enhanced by the presence of cystic fibrosis (CF)-related liver disease. CASE SUMMARY: A 9-year-old girl with CF and cirrhosis experienced a decline in lung function that led to a diagnosis of asthma. After initiation of asthma therapy with inhaled fluticasone 110 µg/actuation, the patient experienced improvement in lung function to baseline. Seven weeks after the initiation of inhaled fluticasone, she developed vaginal candidiasis and was prescribed fluconazole 100 mg/day, a CYP3A4 inhibitor. Three days after starting fluconazole, she developed polyuria and polydipsia and was found to have severe hyperglycemia, which led to the diagnosis of Cushing syndrome. Fluticasone was discontinued, and the patient's adrenal function normalized. DISCUSSION: Patients with CF are commonly prescribed complex medication regimens that may affect drug metabolism. CYP3A4 inhibitors may significantly decrease metabolic clearance in patients using chronic inhaled corticosteroids. Iatrogenic Cushing syndrome has been reported in patients with CF treated concomitantly, and for extended duration, with inhaled corticosteroids and CYP3A4 inhibitors. This case highlights rapid onset of adrenal insufficiency in a patient with CF-related liver disease treated briefly with a moderate CYP3A4 inhibitor. Use of the Horn drug interaction probability scale indicates that the interaction between fluticasone and fluconazole was probable. CONCLUSIONS: CYP3A4-mediated drug interactions represent a significant risk in patients treated with long-term inhaled corticosteroids. The presence of clinically significant CF-related liver disease may enhance this risk.