Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 79
Filter
Add more filters

Publication year range
1.
J Clin Immunol ; 44(5): 107, 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38676811

ABSTRACT

PURPOSE: Patients with adenosine deaminase 1 deficient severe combined immunodeficiency (ADA-SCID) are initially treated with enzyme replacement therapy (ERT) with polyethylene glycol-modified (PEGylated) ADA while awaiting definitive treatment with hematopoietic stem cell transplant (HSCT) or gene therapy. Beginning in 1990, ERT was performed with PEGylated bovine intestinal ADA (ADAGEN®). In 2019, a PEGylated recombinant bovine ADA (Revcovi®) replaced ADAGEN following studies in older patients previously treated with ADAGEN for many years. There are limited longitudinal data on ERT-naïve newborns treated with Revcovi. METHODS: We report our clinical experience with Revcovi as initial bridge therapy in three newly diagnosed infants with ADA-SCID, along with comprehensive biochemical and immunologic data. RESULTS: Revcovi was initiated at twice weekly dosing (0.2 mg/kg intramuscularly), and monitored by following plasma ADA activity and the concentration of total deoxyadenosine nucleotides (dAXP) in erythrocytes. All patients rapidly achieved a biochemically effective level of plasma ADA activity, and red cell dAXP were eliminated within 2-3 months. Two patients reconstituted B-cells and NK-cells within the first month of ERT, followed by naive T-cells one month later. The third patient reconstituted all lymphocyte subsets within the first month of ERT. One patient experienced declining lymphocyte counts with improvement following Revcovi dose escalation. Two patients developed early, self-resolving thrombocytosis, but no thromboembolic events occurred. CONCLUSION: Revcovi was safe and effective as initial therapy to restore immune function in these newly diagnosed infants with ADA-SCID, however, time course and degree of reconstitution varied. Revcovi dose may need to be optimized based on immune reconstitution, clinical status, and biochemical data.


Subject(s)
Adenosine Deaminase , Agammaglobulinemia , Enzyme Replacement Therapy , Severe Combined Immunodeficiency , Animals , Female , Humans , Infant , Infant, Newborn , Male , Adenosine Deaminase/deficiency , Adenosine Deaminase/genetics , Agammaglobulinemia/therapy , Immune Reconstitution , Recombinant Proteins/therapeutic use , Severe Combined Immunodeficiency/therapy , Treatment Outcome
2.
Retrovirology ; 19(1): 10, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35642061

ABSTRACT

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.


Subject(s)
Cannabis , HIV Infections , HIV-1 , Substance-Related Disorders , Tobacco Products , Adolescent , HIV Infections/drug therapy , HIV-1/genetics , Humans
3.
Am J Hum Genet ; 105(3): 549-561, 2019 09 05.
Article in English | MEDLINE | ID: mdl-31447097

ABSTRACT

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.


Subject(s)
Forkhead Transcription Factors/genetics , Heterozygote , Lymphopenia/genetics , T-Lymphocytes/metabolism , Thymus Gland/cytology , Adult , Aged , Animals , Child, Preschool , Female , Forkhead Transcription Factors/physiology , Humans , Infant , Infant, Newborn , Male , Mice , Mice, SCID , Middle Aged , Young Adult
4.
J Clin Immunol ; 41(7): 1597-1606, 2021 10.
Article in English | MEDLINE | ID: mdl-34184208

ABSTRACT

PURPOSE: Adenosine deaminase (ADA) deficiency causes severe combined immunodeficiency (SCID) through an accumulation of toxic metabolites within lymphocytes. Recently, ADA deficiency has been successfully treated using lentiviral-transduced autologous CD34+ cells carrying the ADA gene. T and B cell function appears to be fully restored, but in many patients' B cell numbers remain low, and assessments of the immunoglobulin heavy (IgHV) repertoire following gene therapy are lacking. METHODS: We performed deep sequencing of IgHV repertoire in peripheral blood lymphocytes from a child following lentivirus-based gene therapy for ADA deficiency and compared to the IgHV repertoire in healthy infants and adults. RESULTS: After gene therapy, Ig diversity increased over time as evidenced by V, D, and J gene usage, N-additions, CDR3 length, extent of somatic hypermutation, and Ig class switching. There was the emergence of predominant IgHM, IgHG, and IgHA CDR3 lengths after gene therapy indicating successful oligoclonal expansion in response to antigens. This provides proof of concept for the feasibility and utility of molecular monitoring in following B cell reconstitution following gene therapy for ADA deficiency. CONCLUSION: Based on deep sequencing, gene therapy resulted in an IgHV repertoire with molecular diversity similar to healthy infants.


Subject(s)
Agammaglobulinemia/immunology , Immunoglobulin Heavy Chains/immunology , Severe Combined Immunodeficiency/immunology , Adenosine Deaminase/deficiency , Adenosine Deaminase/therapeutic use , Agammaglobulinemia/therapy , Enzyme Replacement Therapy , Female , Genetic Therapy , Humans , Infant , Lymphocyte Count , Severe Combined Immunodeficiency/therapy
5.
Eur J Immunol ; 50(11): 1729-1745, 2020 11.
Article in English | MEDLINE | ID: mdl-32525220

ABSTRACT

Diacylglycerol kinases (DGKs) play important roles in restraining diacylglycerol (DAG)-mediated signaling. Within the DGK family, the ζ isoform appears to be the most important isoform in T cells for controlling their development and function. DGKζ has been demonstrated to regulate T cell maturation, activation, anergy, effector/memory differentiation, defense against microbial infection, and antitumor immunity. Given its critical functions, DGKζ function should be tightly regulated to ensure proper signal transduction; however, mechanisms that control DGKζ function are still poorly understood. We report here that DGKζ dynamically translocates from the cytosol into the nuclei in T cells after TCR stimulation. In mice, DGKζ mutant defective in nuclear localization displayed enhanced ability to inhibit TCR-induced DAG-mediated signaling in primary T cells, maturation of conventional αßT and iNKT cells, and activation of peripheral T cells compared with WT DGKζ. Our study reveals for the first time nuclear sequestration of DGKζ as a negative control mechanism to spatially restrain it from terminating DAG mediated signaling in T cells. Our data suggest that manipulation of DGKζ nucleus-cytosol shuttling as a novel strategy to modulate DGKζ activity and immune responses for treatment of autoimmune diseases and cancer.


Subject(s)
Diacylglycerol Kinase/metabolism , Diglycerides/metabolism , Receptors, Antigen, T-Cell/metabolism , Signal Transduction/physiology , Animals , Autoimmune Diseases/metabolism , Cell Differentiation/physiology , Cell Nucleus/metabolism , Cytosol/metabolism , Mice , Mice, Inbred C57BL , Neoplasms/metabolism
6.
Am J Med Genet A ; 173(5): 1219-1225, 2017 May.
Article in English | MEDLINE | ID: mdl-28317311

ABSTRACT

Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) syndrome is a rare, X-linked recessive disease that affects regulatory T cells (Tregs) resulting in diarrhea, enteropathy, eczema, and insulin-dependent diabetes mellitus. IPEX syndrome is caused by pathogenic alterations in FOXP3 located at Xp11.23. FOXP3 encodes a transcription factor that interacts with several partners, including NFAT and NF-κB, and is necessary for the proper cellular differentiation of Tregs. Although variable, the vast majority of IPEX syndrome patients have onset of disease during infancy with severe enteropathy. Only five families with prenatal presentation of IPEX syndrome have been reported. Here, we present two additional prenatal onset cases with novel inherited frameshift pathogenic variants in FOXP3 that generate premature stop codons. Ultrasound findings in the first patient identified echogenic bowel, echogenic debris, scalp edema, and hydrops. In the second patient, ultrasound findings included polyhydramnios with echogenic debris, prominent fluid-filled loops of bowel, and echogenic bowel. These cases further broaden the phenotypic spectrum of IPEX syndrome by describing previously unappreciated prenatal ultrasound findings associated with the disease.


Subject(s)
Cell Differentiation/genetics , Diabetes Mellitus, Type 1/congenital , Diarrhea/diagnosis , Diarrhea/genetics , Forkhead Transcription Factors/genetics , Genetic Diseases, X-Linked/diagnosis , Genetic Diseases, X-Linked/genetics , Immune System Diseases/congenital , Adult , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/physiopathology , Diarrhea/physiopathology , Female , Fetus , Forkhead Transcription Factors/immunology , Frameshift Mutation , Genetic Diseases, X-Linked/physiopathology , Humans , Immune System Diseases/diagnosis , Immune System Diseases/genetics , Immune System Diseases/physiopathology , Male , NF-kappa B/genetics , NFATC Transcription Factors/genetics , Pregnancy , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/pathology , Ultrasonography, Prenatal
7.
J Neurovirol ; 22(2): 218-30, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26463526

ABSTRACT

Although youth living with behaviorally acquired HIV (YLWH) are at risk for cognitive impairments, the relationship of impairments to HIV and potential to improve with antiretroviral therapy (ART) are unclear. This prospective observational study was designed to examine the impact of initiation and timing of ART on neurocognitive functioning in YLWH in the Adolescent Medicine Trials Network for HIV/AIDS Interventions. Treatment naïve YLWH age 18-24 completed baseline and four additional assessments of attention/working memory, complex executive, and motor functioning over 3 years. Group 1 co-enrolled in an early ART initiation study and initiated ART at enrollment CD4 >350 (n = 56); group 2 had CD4 >350 and were not initiating ART (n = 66); group 3 initiated ART with CD4 <350 (n = 59) per standard of care treatment guidelines at the time. Treatment was de-intensified to boosted protease inhibitor monotherapy at 48 weeks for those in group 1 with suppressed viral load. Covariates included demographic, behavioral, and medical history variables. Analyses used hierarchical linear modeling. All groups showed improved performance with peak at 96 weeks in all three functional domains. Trajectories of change were not significantly associated with treatment, timing of treatment initiation, or ART de-intensification. Demographic variables and comorbidities were associated with baseline functioning but did not directly interact with change over time. In conclusion, YLWH showed improvement in neurocognitive functioning over time that may be related to practice effects and nonspecific impact of study participation. Neither improvement nor decline in functioning was associated with timing of ART initiation or therapy de-intensification.


Subject(s)
Anti-HIV Agents/therapeutic use , Cognitive Dysfunction/drug therapy , HIV Infections/drug therapy , Models, Statistical , Adolescent , Antiretroviral Therapy, Highly Active , Attention/drug effects , CD4 Lymphocyte Count , Cognitive Dysfunction/complications , Cognitive Dysfunction/physiopathology , Cognitive Dysfunction/virology , Drug Administration Schedule , Executive Function/drug effects , Female , HIV Infections/complications , HIV Infections/physiopathology , HIV Infections/virology , HIV-1/drug effects , HIV-1/physiology , Humans , Male , Memory, Short-Term/drug effects , Neuropsychological Tests , Prospective Studies , Psychomotor Performance/drug effects , Time Factors , Viral Load/drug effects , Young Adult
8.
BMC Immunol ; 16: 43, 2015 Jul 24.
Article in English | MEDLINE | ID: mdl-26204934

ABSTRACT

BACKGROUND: Systemic immune activation (inflammation) and immunosenescence develop in some people with advancing age. This process, known as "inflamm-aging," is associated with physical frailty and sarcopenia. Meanwhile, successful antiretroviral therapy has led to a growing number of older HIV-1-infected individuals who face both age-related and HIV-1-related inflammation, which may synergistically promote physical decline, including frailty and sarcopenia. The purpose of our study was to determine if inflammation during treated HIV-1 infection worsens physical impairment in older individuals. METHODS: We determined the severity of HIV-associated inflammation and physical performance (strength and endurance) in 21 older HIV-infected individuals (54-69 years) receiving suppressive antiretroviral therapy, balanced for confounding variables including age, anthropometrics, and co-morbidities with 10 uninfected control individuals. Biomarkers for microbial translocation (lipopolysaccharide [LPS]), inflammation (soluble CD14 [sCD14], osteopontin, C-reactive protein [CRP], interleukin-6 [IL-6], soluble ICAM-1 [sICAM-1] and soluble VCAM-1 [sVCAM-1]), and coagulopathy (D-dimer) were assayed in plasma. Activation phenotypes of CD4(+)T cells, CD8(+) T cells and monocytes were measured by flow cytometry. Physical performance was measured by 400 m walking speed, a short physical performance battery [SPPB], and lower extremity muscle strength and fatigue. RESULTS: Overall physical function was similar in the uninfected and HIV-infected groups. Compared to uninfected individuals, the HIV-infected group had elevated levels of sCD14 (P < 0.001), CRP (P < 0.001) and IL-6 (P = 0.003) and an increased frequency of CD4(+) and CD8(+) T cells with an immunosenescent CD57(+) phenotype (P = 0.004 and P = 0.043, respectively). Neither plasma inflammatory biomarkers nor CD57(+) T cells correlated with CD4(+) T cell counts. Furthermore, none of the elevated inflammatory biomarkers in the HIV-infected subjects were associated with any of the physical performance results. CONCLUSIONS: When age-related co-morbidities were carefully balanced between the uninfected and HIV-infected groups, no evidence of inflammation-associated physical impairment was detected. Despite careful balancing for age, BMI, medications and co-morbidities, the HIV-infected group still displayed evidence of significant chronic inflammation, including elevated sCD14, CRP, IL-6 and CD57(+) T cells, although the magnitude of this inflammation was unrelated to physical impairment.


Subject(s)
HIV Infections/immunology , HIV-1/immunology , Inflammation/immunology , Motor Activity , Aged , Biomarkers/blood , Cell Count , Cohort Studies , HIV Infections/microbiology , Humans , Immunity, Innate , Immunologic Memory , Lymphocyte Activation/immunology , Middle Aged , Monocytes/metabolism , T-Lymphocytes/immunology
9.
Ann Otol Rhinol Laryngol ; 124(2): 102-6, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25063683

ABSTRACT

BACKGROUND: Mannose-binding lectin (MBL) is a protein produced by the liver that participates in innate immunity by tagging the surface of microbes for opsonization. Mannose-binding lectin deficiency is present in 7% of the population and has been implicated in recurrent respiratory tract infections in children. Mannose-binding lectin deficiency has not been explored in rhinosinusitis but is associated with increased mortality in adult pneumococcal infection. The purpose of this report is to describe a tertiary rhinology patient experience with MBL deficiency and recalcitrant rhinosinusitis. METHODS: This retrospective case series report characterizes predominantly adult patients with low MBL levels from January 2010 to June 2012. Indications for MBL testing, sinus culture data, immunological testing results, and treatments used to control rhinosinusitis are described. RESULTS: Mannose-binding lectin levels were deficient in 12 of 36 patients (33.3%) tested. IgG subclasses were abnormally low in 5 of 12 patients; IgA was normal in 11 of 12 patients; and IgM was normal in 11 of 12 patients. Staphylococcus aureus, coagulase-negative Staphylococcus species, and Pseudomonas aeruginosa, known to be "tagged" by MBL, were the most common organisms grown on culture. Treatments included culture directed systemic antimicrobial therapy and topical steroids/antibiotics. CONCLUSION: Mannose-binding lectin, an important component of the lectin complement pathway and innate immunity, is possibly associated with recalcitrant adult rhinosinusitis. Steroid/antibiotic irrigations appear to benefit patients with recalcitrant rhinosinusitis and possibly those with MBL deficiency. Given that the prevalence of MBL deficiency in this case series is 4 times that seen in the normal population, additional investigations are warranted to further elucidate the role of MBL deficiency in rhinosinusitis.


Subject(s)
Adrenal Cortex Hormones/administration & dosage , Anti-Infective Agents/administration & dosage , Immunity, Innate , Mannose-Binding Lectin/deficiency , Metabolism, Inborn Errors , Rhinitis , Sinusitis , Adolescent , Adult , Anti-Inflammatory Agents/administration & dosage , Complement Pathway, Mannose-Binding Lectin , Drug Administration Routes , Female , Humans , Immunologic Tests/methods , Male , Mannose-Binding Lectin/immunology , Mannose-Binding Lectins/blood , Metabolism, Inborn Errors/complications , Metabolism, Inborn Errors/immunology , Microbial Sensitivity Tests , Middle Aged , Pseudomonas aeruginosa/isolation & purification , Retrospective Studies , Rhinitis/complications , Rhinitis/diagnosis , Rhinitis/microbiology , Rhinitis/physiopathology , Rhinitis/therapy , Sinusitis/complications , Sinusitis/diagnosis , Sinusitis/microbiology , Sinusitis/physiopathology , Sinusitis/therapy , Staphylococcus aureus/isolation & purification , Treatment Outcome
10.
J Clin Immunol ; 34(1): 39-41, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24217814

ABSTRACT

A 16-year old boy with chronic granulomatous disease (CGD) developed Psychrobacter immobilis septicemia during a course of fulminant hepatic failure. The patient died despite aggressive management with antimicrobials and corticosteroids. While Psychrobacter immobilis rarely affects humans, it should be considered an organism that can cause sepsis in patients with CGD.


Subject(s)
Bacteremia/complications , Granulomatous Disease, Chronic/complications , Liver Failure, Acute/complications , Moraxellaceae Infections/complications , Psychrobacter , Adolescent , Anti-Bacterial Agents/therapeutic use , Autopsy , Bacteremia/drug therapy , Fatal Outcome , Granulomatous Disease, Chronic/diagnosis , Humans , Liver Failure, Acute/diagnosis , Male , Moraxellaceae Infections/diagnosis , Moraxellaceae Infections/drug therapy
11.
J Virol ; 87(18): 10004-15, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23824804

ABSTRACT

Anti-human immunodeficiency virus (HIV) cytotoxic T lymphocyte (CTL)-associated epitopes, evolutionarily conserved on both HIV type 1 (HIV-1) and feline immunodeficiency virus (FIV) reverse transcriptases (RT), were identified using gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) and carboxyfluorescein diacetate succinimide ester (CFSE) proliferation assays followed by CTL-associated cytotoxin analysis. The peripheral blood mononuclear cells (PBMC) or T cells from HIV-1-seropositive (HIV(+)) subjects were stimulated with overlapping RT peptide pools. The PBMC from the HIV(+) subjects had more robust IFN-γ responses to the HIV-1 peptide pools than to the FIV peptide pools, except for peptide-pool F3. In contrast, much higher and more frequent CD8(+) T-cell proliferation responses were observed with the FIV peptide pools than with the HIV peptide pools. HIV-1-seronegative subjects had no proliferation or IFN-γ responses to the HIV and FIV peptide pools. A total of 24% (40 of 166) of the IFN-γ responses to HIV pools and 43% (23 of 53) of the CD8(+) T-cell proliferation responses also correlated to responses to their counterpart FIV pools. Thus, more evolutionarily conserved functional epitopes were identified by T-cell proliferation than by IFN-γ responses. In the HIV(+) subjects, peptide-pool F3, but not the HIV H3 counterpart, induced the most IFN-γ and proliferation responses. These reactions to peptide-pool F3 were highly reproducible and persisted over the 1 to 2 years of testing. All five individual peptides and epitopes of peptide-pool F3 induced IFN-γ and/or proliferation responses in addition to inducing CTL-associated cytotoxin responses (perforin, granzyme A, granzyme B). The epitopes inducing polyfunctional T-cell activities were highly conserved among human, simian, feline, and ungulate lentiviruses, which indicated that these epitopes are evolutionarily conserved. These results suggest that FIV peptides could be used in an HIV-1 vaccine.


Subject(s)
Epitopes/immunology , HIV-1/immunology , Immunodeficiency Virus, Feline/immunology , RNA-Directed DNA Polymerase/immunology , T-Lymphocytes, Cytotoxic/immunology , Adult , Aged , Animals , Cell Proliferation , Conserved Sequence , Enzyme-Linked Immunospot Assay , Epitopes/genetics , Female , HIV-1/genetics , Humans , Immunodeficiency Virus, Feline/genetics , Interferon-gamma/metabolism , Leukocytes, Mononuclear/immunology , Male , Middle Aged , RNA-Directed DNA Polymerase/genetics , Young Adult
12.
Front Pediatr ; 12: 1365187, 2024.
Article in English | MEDLINE | ID: mdl-38516355

ABSTRACT

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.

13.
Blood Adv ; 2024 May 20.
Article in English | MEDLINE | ID: mdl-38768429

ABSTRACT

Warts, Hypogammglobulinemia, Infections, Myelokathexis (WHIM) syndrome is a rare immunodeficiency disease that results from impaired leukocyte trafficking (myelokathexis) predominately caused by gain-of-function variants in C-X-C chemokine receptor type 4 (CXCR4). Clinical manifestations of WHIM syndrome can differ in familial forms or in people harboring identical CXCR4 variants. All known pathogenic CXCR4 variants associated with WHIM syndrome (CXCR4WHIM) to date are localized in the intracellular C-terminus of CXCR4. We identified 4 unrelated patients with variable WHIM-like clinical presentations harboring a novel heterozygous CXCR4 variant (c.250G>C; p.D84H) localized at a highly conserved position in the transmembrane domain of the receptor outside the C-terminus. Functional characterization of the CXCR4D84Hvariant (CXCR4D84H) using patient-derived peripheral blood mononuclear cells and in vitro cellular assaysshow decreased CXCR4 internalization and increased chemotaxis in response to CXCL12, similar to known CXCR4WHIM, but also revealed unique features of CXCR4D84H signaling to cAMP, Ca2+ mobilization and AKT/ERK pathways. These findings are consistent with molecular dynamics simulations that show disruption of the Na+ binding pocket by D84H, resulting in collapse of the hydrophobic gate above and destabilization of the inactive state of CXCR4. Mavorixafor, a CXCR4 antagonist being evaluated in clinical trials for chronic neutropenia and WHIM syndrome, normalized CXCL12-mediated chemotaxis of CXCR4D84H patient lymphocytes ex vivo and improved WBC and subset counts in 1 patient with CXCR4D84H enrolled in the chronic neutropenia phase 1b clinical trial (NCT04154488). The present study expands the current understanding of CXCR4 function and genotype-phenotype correlations in WHIM syndrome and in people with WHIM-like phenotypes.

14.
J Clin Immunol ; 33(5): 984-90, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23456255

ABSTRACT

PURPOSE: US licensing studies of subcutaneous IgG (SCIG) calculate dose adjustments necessary to achieve area under the curve (AUC) of serum IgG vs. time on SCIG that is non-inferior to that on intravenous IgG (IVIG), within the FDA-set limit of ±20%. The results are interpreted as showing that different SCIGs differ in bioavailability. We used three approaches to determine if the bioavailabilities were actually different. METHODS: Dose adjustments and AUCs from published licensing studies were used to calculate bioavailabilities using the formula: Bioavailability (% of IVIG) = AUC(SCIG) ÷ AUC(IVIG) x 1/Dose Adjustment. We also compared the increment in serum IgG concentration achieved with varying doses of SCIG in recent meta-analyses with the increment with different doses of IVIG, and determined the serum IgG concentrations when patients switched SCIG products at the same dose. RESULTS: The actual bioavailabilities were: Gamunex® 65.0%, Hizentra® 65.5%, Gammagard® 67.2%, Vivaglobin® 69.0%. Regression analyses of serum IgG vs. dose showed that the mean increase in serum IgG resulting from a 100 mg/kg/month increment in SCIG dosing was 69.4% of the increase with the same increment in IVIG dosing (84 mg/dL vs. 121 mg/dL). Patients switching SCIG preparations at the same dose had no change in serum IgG levels, confirming that bioavailabilities of the SCIG preparations did not differ. CONCLUSIONS: Decreased bioavailability appears to be a basic property of SCIG and not a result of any manufacturing process or concentration. Because serum IgG levels do not vary with different SCIG products at the same dose, adjustments are not necessary when switching products.


Subject(s)
Immunoglobulin G/administration & dosage , Immunoglobulin G/metabolism , Adolescent , Adult , Aged , Area Under Curve , Biological Availability , Child , Humans , Injections, Subcutaneous , Middle Aged , Young Adult
16.
Front Immunol ; 14: 1152538, 2023.
Article in English | MEDLINE | ID: mdl-37251388

ABSTRACT

Introduction: Factors influencing vaccine immune priming in the first year of life involve both innate and adaptive immunity but there are gaps in understanding how these factors sustain vaccine antibody levels in healthy infants. The hypothesis was that bioprofiles associated with B cell survival best predict sustained vaccine IgG levels at one year. Methods: Longitudinal study of plasma bioprofiles in 82 term, healthy infants, who received standard recommended immunizations in the United States, with changes in 15 plasma biomarker concentrations and B cell subsets associated with germinal center development monitored at birth, soon after completion of the initial vaccine series at 6 months, and prior to the 12-month vaccinations. Post vaccination antibody IgG levels to Bordetella pertussis, tetanus toxoid, and conjugated Haemophilus influenzae type B (HiB) were outcome measures. Results: Using a least absolute shrinkage and selection operator (lasso) regression model, cord blood (CB) plasma IL-2, IL-17A, IL-31, and soluble CD14 (sCD14) were positively associated with pertussis IgG levels at 12 months, while CB plasma concentrations of APRIL and IL-33 were negatively associated. In contrast, CB concentrations of sCD14 and APRIL were positively associated with sustained tetanus IgG levels. A separate cross-sectional analysis of 18 mother/newborn pairs indicated that CB biomarkers were not due to transplacental transfer, but rather due to immune activation at the fetal/maternal interface. Elevated percentages of cord blood switched memory B cells were positively associated with 12-month HiB IgG levels. BAFF concentrations at 6 and 12 months were positively associated with pertussis and HiB IgG levels respectively. Discussion: Sustained B cell immunity is highly influenced by early life immune dynamics beginning prior to birth. The findings provide important insights into how germinal center development shapes vaccine responses in healthy infants and provide a foundation for studies of conditions that impair infant immune development.


Subject(s)
Whooping Cough , Infant, Newborn , Humans , Infant , Longitudinal Studies , Fetal Blood , Cross-Sectional Studies , Lipopolysaccharide Receptors , Tetanus Toxoid , Immunoglobulin G
17.
Retrovirology ; 9: 108, 2012 Dec 17.
Article in English | MEDLINE | ID: mdl-23244298

ABSTRACT

BACKGROUND: Deep sequencing provides the basis for analysis of biodiversity of taxonomically similar organisms in an environment. While extensively applied to microbiome studies, population genetics studies of viruses are limited. To define the scope of HIV-1 population biodiversity within infected individuals, a suite of phylogenetic and population genetic algorithms was applied to HIV-1 envelope hypervariable domain 3 (Env V3) within peripheral blood mononuclear cells from a group of perinatally HIV-1 subtype B infected, therapy-naïve children. RESULTS: Biodiversity of HIV-1 Env V3 quasispecies ranged from about 70 to 270 unique sequence clusters across individuals. Viral population structure was organized into a limited number of clusters that included the dominant variants combined with multiple clusters of low frequency variants. Next generation viral quasispecies evolved from low frequency variants at earlier time points through multiple non-synonymous changes in lineages within the evolutionary landscape. Minor V3 variants detected as long as four years after infection co-localized in phylogenetic reconstructions with early transmitting viruses or with subsequent plasma virus circulating two years later. CONCLUSIONS: Deep sequencing defines HIV-1 population complexity and structure, reveals the ebb and flow of dominant and rare viral variants in the host ecosystem, and identifies an evolutionary record of low-frequency cell-associated viral V3 variants that persist for years. Bioinformatics pipeline developed for HIV-1 can be applied for biodiversity studies of virome populations in human, animal, or plant ecosystems.


Subject(s)
Genetic Variation , HIV-1/genetics , Cluster Analysis , Evolution, Molecular , HIV Envelope Protein gp120/genetics , HIV Infections/virology , High-Throughput Nucleotide Sequencing , Humans , Leukocytes, Mononuclear/virology
18.
J Allergy Clin Immunol ; 127(6): 1360-7.e6, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21497890

ABSTRACT

BACKGROUND: Common variable immunodeficiency (CVID) is a heterogeneous immune defect characterized by hypogammaglobulinemia, failure of specific antibody production, susceptibility to infections, and an array of comorbidities. OBJECTIVE: To address the underlying immunopathogenesis of CVID and comorbidities, we conducted the first genome-wide association and gene copy number variation (CNV) study in patients with CVID. METHODS: Three hundred sixty-three patients with CVID from 4 study sites were genotyped with 610,000 single nucleotide polymorphisms (SNPs). Patients were divided into a discovery cohort of 179 cases in comparison with 1,917 control subjects and a replication cohort of 109 cases and 1,114 control subjects. RESULTS: Our analyses detected strong association with the MHC region and association with a disintegrin and metalloproteinase (ADAM) genes (P combined = 1.96 × 10(-7)) replicated in the independent cohort. CNV analysis defined 16 disease-associated deletions and duplications, including duplication of origin recognition complex 4L (ORC4L) that was unique to 15 cases (P = 8.66 × 10(-16)), as well as numerous unique rare intraexonic deletions and duplications suggesting multiple novel genetic causes of CVID. Furthermore, the 1,000 most significant SNPs were strongly predictive of the CVID phenotype by using a Support Vector Machine algorithm with positive and negative predictive values of 1.0 and 0.957, respectively. CONCLUSION: Our integrative genome-wide analysis of SNP genotypes and CNVs has uncovered multiple novel susceptibility loci for CVID, both common and rare, which is consistent with the highly heterogeneous nature of CVID. These results provide new mechanistic insights into immunopathogenesis based on these unique genetic variations and might allow for improved diagnosis of CVID based on accurate prediction of the CVID clinical phenotypes by using our Support Vector Machine model.


Subject(s)
Common Variable Immunodeficiency/genetics , Algorithms , Artificial Intelligence , Case-Control Studies , Cohort Studies , DNA Copy Number Variations , Gene Frequency , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Polymorphism, Single Nucleotide
19.
Autoimmunity ; 55(8): 620-631, 2022 12.
Article in English | MEDLINE | ID: mdl-36036539

ABSTRACT

Antagonism of the neonatal Fc receptor (FcRn) by efgartigimod has been studied in several autoimmune diseases mediated by immunoglobulin G (IgG) as a therapeutic approach to remove pathogenic IgGs. Whereas reduction of pathogenic titres has demonstrated efficacy in multiple autoimmune diseases, reducing total IgG could potentially increase infection risk in patients receiving FcRn antagonists. The objective of this study was to analyse the effect of FcRn antagonism with efgartigimod on existing protective antibody titres and the ability to mount an immune response after vaccine challenge. Serum levels of total IgG and protective antibodies against tetanus toxoid (TT), varicella zoster virus (VZV), and pneumococcal capsular polysaccharide (PCP) were measured in all patients enrolled in an open-label trial of efgartigimod for the treatment of pemphigus. Vaccine specific-responses were assessed by measuring changes in IgG titres in patients with generalised myasthenia gravis (gMG) who were treated with efgartigimod and who received influenza, pneumococcal, or coronavirus disease 2019 (COVID-19) vaccines during participation in the double-blind trial ADAPT or open-label extension, ADAPT+ (n = 17). FcRn antagonism reduced levels of protective anti-TT, anti-VZV, and anti-PCP antibodies and total IgG to a similar extent; anti-TT and anti-VZV titres remained above minimally protective thresholds for the majority of patients, (10/12) 83% and (14/15) 93% respectively. Protective antibodies returned to baseline values upon treatment cessation. Antigen-specific IgG responses to influenza, pneumococcal, and COVID-19 immunisation were detected in patients with gMG who received these vaccines while undergoing therapy with efgartigimod. In conclusion, FcRn antagonism with efgartigimod did not hamper generation of IgG responses but did transiently reduce IgG titres of all specificities.


Subject(s)
COVID-19 , Influenza, Human , Myasthenia Gravis , Pemphigus , Humans , Immunoglobulin G , Infant, Newborn , Polysaccharides , Randomized Controlled Trials as Topic , Tetanus Toxoid/therapeutic use
20.
Front Immunol ; 12: 623280, 2021.
Article in English | MEDLINE | ID: mdl-33732245

ABSTRACT

Expression of tissue-restricted antigens (TRAs) in thymic epithelial cells (TECs) ensures negative selection of highly self-reactive T cells to establish central tolerance. Whether some of these TRAs could exert their canonical biological functions to shape thymic environment to regulate T cell development is unclear. Analyses of publicly available databases have revealed expression of transcripts at various levels of many cytokines and cytokine receptors such as IL-15, IL-15Rα, IL-13, and IL-23a in both human and mouse TECs. Ablation of either IL-15 or IL-15Rα in TECs selectively impairs type 1 innate like T cell, such as iNKT1 and γδT1 cell, development in the thymus, indicating that TECs not only serve as an important source of IL-15 but also trans-present IL-15 to ensure type 1 innate like T cell development. Because type 1 innate like T cells are proinflammatory, our data suggest the possibility that TEC may intrinsically control thymic inflammatory innate like T cells to influence thymic environment.


Subject(s)
Epithelial Cells/metabolism , Immunity, Innate , Interleukin-15/metabolism , Receptors, Interleukin-15/metabolism , T-Lymphocyte Subsets/metabolism , Thymocytes/metabolism , Thymus Gland/metabolism , Animals , Cell Communication , Cellular Microenvironment , Databases, Genetic , Epithelial Cells/immunology , Humans , Interleukin-15/genetics , Intraepithelial Lymphocytes/immunology , Intraepithelial Lymphocytes/metabolism , Mice , Mice, Knockout , Natural Killer T-Cells/immunology , Natural Killer T-Cells/metabolism , Receptors, Interleukin-15/genetics , Signal Transduction , T-Lymphocyte Subsets/immunology , Thymocytes/immunology , Thymus Gland/cytology , Thymus Gland/immunology
SELECTION OF CITATIONS
SEARCH DETAIL