Browsing by Author "Sleasman, John W"

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    ItemOpen Access
    Anti-inflammatory effects of recreational marijuana in virally suppressed youth with HIV-1 are reversed by use of tobacco products in combination with marijuana.
    (Retrovirology, 2022-05-31) Yin, Li; Dinasarapu, Ashok R; Borkar, Samiksha A; Chang, Kai-Fen; De Paris, Kristina; Kim-Chang, Julie J; Sleasman, John W; Goodenow, Maureen M

    Background

    Marijuana's putative anti-inflammatory properties may benefit HIV-associated comorbidities. How recreational marijuana use affects gene expression in peripheral blood cells (PBC) among youth with HIV-1 (YWH) is unknown.

    Approach

    YWH with defined substance use (n = 54) receiving similar antiretroviral therapy (ART) were assigned to one of four analysis groups: YWH with detectable plasma HIV-1 (> 50 RNA copies/ml) who did not use substances (H+V+S-), and YWH with undetectable plasma HIV-1 who did not use substances (H+V-S-), or used marijuana alone (H+V-S+[M]), or marijuana in combination with tobacco (H+V-S+[M/T]). Non-substance using youth without HIV infection (H-S-, n = 25) provided a reference group. PBC mRNA was profiled by Affymetrix GeneChip Human Genome U133 Plus 2.0 Array. Differentially expressed genes (DEG) within outcome groups were identified by Significance Analysis of Microarrays and used for Hierarchical Clustering, Principal Component Analysis, and Ingenuity Pathways Analysis.

    Results

    HIV-1 replication resulted in > 3000 DEG involving 27 perturbed pathways. Viral suppression reduced DEG to 313, normalized all 27 pathways, and down-regulated two additional pathways, while marijuana use among virally suppressed YWH resulted in 434 DEG and no perturbed pathways. Relative to H+V-S-, multiple DEG normalized in H+V-S+[M]. In contrast, H+V-S+[M/T] had 1140 DEG and 10 dysregulated pathways, including multiple proinflammatory genes and six pathways shared by H+V+S-.

    Conclusions

    YWH receiving ART display unique transcriptome bioprofiles based on viral replication and substance use. In the context of HIV suppression, marijuana use, alone or combined with tobacco, has opposing effects on inflammatory gene expression.
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    Case Report: Aplastic anemia related to a novel CTLA4 variant.
    (Frontiers in pediatrics, 2024-01) Hall, Geoffrey; Markle, Janet G; Maiarana, James; Martin, Paul L; Rothman, Jennifer A; Sleasman, John W; Lederman, Howard; Azar, Antoine E; Brodsky, Robert A; Mousallem, Talal
    A 20-year-old male patient with a history of celiac disease came to medical attention after developing profound fatigue and pancytopenia. Evaluation demonstrated pan-hypogammaglobulinemia. There was no history of significant clinical infections. Bone marrow biopsy confirmed hypocellular marrow consistent with aplastic anemia. Oncologic and hematologic evaluations were unremarkable for iron deficiency, paroxysmal nocturnal hemoglobinuria, myelodysplastic syndromes, T-cell clonality, and leukemia. A next generation genetic sequencing immunodeficiency panel revealed a heterozygous variant of uncertain significance in CTLA4 c.385T >A, p.Cys129Ser (C129S). Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is an inhibitory receptor important in maintaining immunologic homeostasis. To determine the functional significance of the C129S variant, additional testing was pursued to assess for diminished protein expression, as described in other pathogenic CTLA4 variants. The results demonstrated severely impaired CTLA-4 expression and CD80 transendocytosis, consistent with other variants causing CTLA-4 haploinsufficiency. He was initially treated with IVIG and cyclosporine, and became transfusion independent for few months, but relapsed. Treatment with CTLA-4-Ig fusion protein (abatacept) was considered, however the patient opted for definitive therapy through reduced-intensity haploidentical hematopoietic stem cell transplant, which was curative.
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    Case Report: Profound newborn leukopenia related to a novel RAC2 variant.
    (Frontiers in pediatrics, 2024-01) Hall, Geoffrey; Donkó, Ágnes; Pratt, Cristina; Kim-Chang, Julie J; Martin, Paul L; Stallings, Amy P; Sleasman, John W; Holland, Steven M; Hsu, Amy P; Leto, Thomas L; Mousallem, Talal
    We report the case of a 1-week-old male born full-term, who had two inconclusive severe combined immunodeficiency (SCID) newborn screens and developed scalp cellulitis and Escherichia coli bacteremia. He did not pass early confirmatory hearing screens. Initial blood counts and lymphocyte flow cytometry revealed profound neutropenia and lymphopenia with a T-/B-/NK- phenotype. Red blood cell adenosine deaminase 1 activity was within normal limits. A presumptive diagnosis of reticular dysgenesis was considered. Granulocyte colony-stimulating factor was started, but there was no improvement in neutrophil counts. Subsequent lymphocyte flow cytometry at around 4 weeks of age demonstrated an increase in T-, B- and NK-cell numbers, eliminating suspicion for SCID and raising concern for congenital neutropenia and bone marrow failure syndromes. Genetic testing revealed a novel variant in RAC2 [c.181C>A (p.Gln61Lys)] (Q61K). RAC2, a Ras-related GTPase, is the dominant RAC protein expressed in hematopoietic cells and is involved with various downstream immune-mediated responses. Pathogenic RAC2 variants show significant phenotypic heterogeneity (spanning from neutrophil defects to combined immunodeficiency) across dominant, constitutively activating, dominant activating, dominant negative, and autosomal recessive subtypes. Given the identification of a novel variant, functional testing was pursued to evaluate aberrant pathways described in other RAC2 pathogenic variants. In comparison to wild-type RAC2, the Q61K variant supported elevated superoxide production under both basal and PMA-stimulated conditions, increased PAK1 binding, and enhanced plasma membrane ruffling, consistent with other dominant, constitutively active mutations. This case highlights the diagnostic challenge associated with genetic variants identified via next-generation sequencing panels and the importance of functional assays to confirm variant pathogenicity.
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    Differential controls of MAIT cell effector polarization by mTORC1/mTORC2 via integrating cytokine and costimulatory signals
    (Nature Communications, 2021-12) Tao, Huishan; Pan, Yun; Chu, Shuai; Li, Lei; Xie, Jinhai; Wang, Peng; Zhang, Shimeng; Reddy, Srija; Sleasman, John W; Zhong, Xiao-Ping
    AbstractMucosal-associated invariant T (MAIT) cells have important functions in immune responses against pathogens and in diseases, but mechanisms controlling MAIT cell development and effector lineage differentiation remain unclear. Here, we report that IL-2/IL-15 receptor β chain and inducible costimulatory (ICOS) not only serve as lineage-specific markers for IFN-γ-producing MAIT1 and IL-17A-producing MAIT17 cells, but are also important for their differentiation, respectively. Both IL-2 and IL-15 induce mTOR activation, T-bet upregulation, and subsequent MAIT cell, especially MAIT1 cell, expansion. By contrast, IL-1β induces more MAIT17 than MAIT1 cells, while IL-23 alone promotes MAIT17 cell proliferation and survival, but synergizes with IL-1β to induce strong MAIT17 cell expansion in an mTOR-dependent manner. Moreover, mTOR is dispensable for early MAIT cell development, yet pivotal for MAIT cell effector differentiation. Our results thus show that mTORC2 integrates signals from ICOS and IL-1βR/IL-23R to exert a crucial role for MAIT17 differentiation, while the IL-2/IL-15R-mTORC1-T-bet axis ensures MAIT1 differentiation.