Parental involvement in decision making about intracranial pressure monitor placement in children with traumatic brain injury.

OBJECTIVE: Little is known about how parents of children with traumatic brain injury (TBI) participate or feel they should participate in decision making regarding placing an intracranial pressure (ICP) monitor. The objective of this study was to identify the perspectives and decisional or information needs of parents whose child sustained a TBI and may require an ICP monitor. METHODS: This was a qualitative study at one US level I pediatric trauma center. The authors conducted in-depth semistructured interviews with 1) parents of critically injured children who have sustained a TBI and 2) clinicians who regularly care for children with TBI. RESULTS: The authors interviewed 10 parents of 7 children (60% were mothers and 80% were white) and 28 clinicians (17 ICU clinicians and 11 surgeons). Overall, the authors found concordance between and among parents and clinicians about parental involvement in ICP monitor decision making. Parents and clinicians agreed that decision making about ICP monitoring in children who have suffered TBI is not and should not be shared between the parents and clinicians. The concordance was represented in 3 emergent themes. Parents wanted transparency, communication, and information (theme 2), but the life-threatening context of this decision (theme 1) created an environment where all involved reflected a clear preference for paternalism (theme 3). CONCLUSIONS: The clear and concordant preference for clinician paternalistic decision making coupled with the parents' needs to be informed suggests that a decision support tool for this decision should be clinician facing and should emphasize transparency in collaborative decision making between clinicians.

Principles and Strategies for Effective Teaching: A Workshop for Pre- and Postdoctoral Trainees in the Biomedical Sciences.

The 2012 National Institutes of Health (NIH) Biomedical Workforce Working Group Report documented that graduate training in the biomedical sciences predominantly prepares people for academic research positions. The report recommended that NIH provide funds for institutions to develop broader career development opportunities, including training related to teaching. Indeed, teaching is not only a required component of any faculty position, it is the primary task for trainees who seek employment at small liberal arts colleges and other primarily undergraduate institutions. NIH funding for the BEST (Broadening Experiences in Scientific Training) programs allowed us to develop a six-week training workshop for bioscience trainees to introduce participants to research-based, student-centered pedagogies and instructional design techniques and to inspire them to view teaching as an intellectual endeavor. The methods and outcomes of our case study should be applicable in a variety of programs and organizations, especially those with a separate health science campus, where faculty mentors often do not teach many classes and there are few, if any, apprenticeship-teaching opportunities for trainees.

TGFß1-Mediated SMAD3 Enhances PD-1 Expression on Antigen-Specific T Cells in Cancer.

Programmed death-1 (PD-1) is a coinhibitory receptor that downregulates the activity of tumor-infiltrating lymphocytes (TIL) in cancer and of virus-specific T cells in chronic infection. The molecular mechanisms driving high PD-1 expression on TILs have not been fully investigated. We demonstrate that TGFß1 enhances antigen-induced PD-1 expression through SMAD3-dependent, SMAD2-independent transcriptional activation in T cells in vitro and in TILs in vivo The PD-1hi subset seen in CD8+ TILs is absent in Smad3-deficient tumor-specific CD8+ TILs, resulting in enhanced cytokine production by TILs and in draining lymph nodes and antitumor activity. In addition to TGFß1's previously known effects on T-cell function, our findings suggest that TGFß1 mediates T-cell suppression via PD-1 upregulation in the tumor microenvironment (TME). They highlight bidirectional cross-talk between effector TILs and TGFß-producing cells that upregulates multiple components of the PD-1 signaling pathway to inhibit antitumor immunity. SIGNIFICANCE: Engagement of the coinhibitory receptor PD-1 or its ligand, PD-L1, dramatically inhibits the antitumor function of TILs within the TME. Our findings represent a novel immunosuppressive function of TGFß and demonstrate that TGFß1 allows tumors to evade host immune responses in part through enhanced SMAD3-mediated PD-1 expression on TILs. Cancer Discov; 6(12); 1366-81. ©2016 AACRThis article is highlighted in the In This Issue feature, p. 1293.

The Causal Role of IL-4 and IL-13 in Schistosoma mansoni Pulmonary Hypertension.

RATIONALE: The etiology of schistosomiasis-associated pulmonary arterial hypertension (PAH), a major cause of PAH worldwide, is poorly understood. Schistosoma mansoni exposure results in prototypical type-2 inflammation. Furthermore, transforming growth factor (TGF)-ß signaling is required for experimental pulmonary hypertension (PH) caused by Schistosoma exposure. OBJECTIVES: We hypothesized type-2 inflammation driven by IL-4 and IL-13 is necessary for Schistosoma-induced TGF-ß-dependent vascular remodeling. METHODS: Wild-type, IL-4(-/-), IL-13(-/-), and IL-4(-/-)IL-13(-/-) mice (C57BL6/J background) were intraperitoneally sensitized and intravenously challenged with S. mansoni eggs to induce experimental PH. Right ventricular catheterization was then performed, followed by quantitative analysis of the lung tissue. Lung tissue from patients with schistosomiasis-associated and connective tissue disease-associated PAH was also systematically analyzed. MEASUREMENTS AND MAIN RESULTS: Mice with experimental Schistosoma-induced PH had evidence of increased IL-4 and IL-13 signaling. IL-4(-/-)IL-13(-/-) mice, but not single knockout IL-4(-/-) or IL-13(-/-) mice, were protected from Schistosoma-induced PH, with decreased right ventricular pressures, pulmonary vascular remodeling, and right ventricular hypertrophy. IL-4(-/-)IL-13(-/-) mice had less pulmonary vascular phospho-signal transducer and activator of transcription 6 (STAT6) and phospho-Smad2/3 activity, potentially caused by decreased TGF-ß activation by macrophages. In vivo treatment with a STAT6 inhibitor and IL-4(-/-)IL-13(-/-) bone marrow transplantation also protected against Schistosoma-PH. Lung tissue from patients with schistosomiasis-associated and connective tissue disease-associated PAH had evidence of type-2 inflammation. CONCLUSIONS: Combined IL-4 and IL-13 deficiency is required for protection against TGF-ß-induced pulmonary vascular disease after Schistosoma exposure, and targeted inhibition of this pathway is a potential novel therapeutic approach for patients with schistosomiasis-associated PAH.

Novosphingobium and its potential role in chronic obstructive pulmonary diseases: insights from microbiome studies.

Bacterial infection of lung airways underlies some of the main complications of COPD, significantly impacting disease progression and outcome. Colonization by bacteria may further synergize, amplify, or trigger pathways of tissue damage started by cigarette smoke, contributing to the characteristic airway inflammation and alveolar destruction of COPD. We sought to elucidate the presence and types of lung bacterial populations in different stages of COPD, aimed at revealing important insights into the pathobiology of the disease. Sequencing of the bacterial small subunit ribosomal RNA gene in 55 well-characterized clinical lung samples, revealed the presence of Novosphingobium spp. (>2% abundance) in lungs of patients with GOLD 3-GOLD 4 COPD, cystic fibrosis and a subset of control individuals. Novosphingobium-specific quantitative PCR was concordant with the sequence data and high levels of Novosphingobium spp. were quantifiable in advanced COPD, but not from other disease stages. Using a mouse model of subacute lung injury due to inhalation of cigarette smoke, bronchoalveolar lavage neutrophil and macrophage counts were significantly higher in mice challenged intratracheally with N. panipatense compared to control mice (p<0.01). Frequencies of neutrophils and macrophages in lung tissue were increased in mice challenged with N. panipatense at room air compared to controls. However, we did not observe an interaction between N. panipatense and subacute cigarette smoke exposure in the mouse. In conclusion, Novosphingobium spp. are present in more severe COPD disease, and increase inflammation in a mouse model of smoke exposure.

Interleukin (IL)-17/IL-22-producing T cells enriched within the liver of patients with chronic hepatitis C viral (HCV) infection.

BACKGROUND: Effector CD4+ helper T cells have historically been classified into T helper 1 (Th1) and Th2 based on the production of signature cytokines. The recently identified interleukin (IL)-17 cytokine family plays important roles in host immunity against intracellular pathogens and in chronic inflammatory conditions; data have implicated IL-17 in autoimmune and viral liver disease. METHODS: This study used three patient groups with HCV infection: acute HCV who either cleared spontaneously or became chronically infected (n = 12), endstage liver disease from whom both peripheral and intrahepatic lymphocytes were studied directly ex vivo (n = 11), and 134 patients with different stages of HCV-related fibrosis from whom serum was collected concurrently with liver biopsy. Normal healthy subjects (n = 41) served as controls. RESULTS: Acute HCV was not associated with expansion of either CD4+ or CD8+ T cells producing IL-17 (Th17, Tc17) or IL-22, and frequencies did not differ in the blood of patients who cleared versus became persistently infected. The hepatic compartment of chronic HCV patients demonstrated statistically more CD4+ and CD8+ that produced IL-17, IL-22 or both as compared to peripheral blood. These T cells displayed a distinct phenotypic profile, high expression of the homing receptor CD161 and low levels of inhibitory receptors, mucin-domain-containing-molecule-3 (Tim-3) and programmed-death 1. Using a sensitive ELISA, we found no significant differences in serum levels of IL-17 according to HCV-related fibrosis. CONCLUSIONS: In chronic HCV, T cells producing IL-17/IL-22 may home to the liver; however, circulating levels of IL-17 do not correlate with fibrosis.

Protective interleukin-28B genotype affects hepatitis C virus clearance, but does not contribute to HIV-1 control in a cohort of African-American elite controllers/suppressors.

We tested the hypothesis that a single nucleotide polymorphism (SNP) located near the interleukin-28B gene is associated with the control of hepatitis C virus and HIV-1 replication in elite controllers/suppressors. We show here that the protective genotype is not overrepresented in elite controllers/suppressors compared with HIV-1-seronegative patients and HIV-1-infected patients with viral loads more than 10 000 copies/ml. Thus, it appears that this SNP is not associated with the elite control of HIV-1 infection.

High-programmed death-1 levels on hepatitis C virus-specific T cells during acute infection are associated with viral persistence and require preservation of cognate antigen during chronic infection.

Hepatitis C virus (HCV) is an important human pathogen that represents a model for chronic infection given that the majority of infected individuals fail to clear the infection despite generation of virus-specific T cell responses during the period of acute infection. Although viral sequence evolution at targeted MHC class I-restricted epitopes represents one mechanism for immune escape in HCV, many targeted epitopes remain intact under circumstances of viral persistence. To explore alternative mechanisms of HCV immune evasion, we analyzed patterns of expression of a major inhibitory receptor on T cells, programmed death-1 (PD-1), from the time of initial infection and correlated these with HCV RNA levels, outcome of infection, and sequence escape within the targeted epitope. We show that the level of PD-1 expression in early HCV infection is significantly higher on HCV-specific T cells from subjects who progress to chronic HCV infection than from those who clear infection. This correlation is independent of HCV RNA levels, compatible with the notion that high PD-1 expression on HCV-specific CD8 T cells during acute infection inhibits viral clearance. Viral escape during persistent infection is associated with reduction in PD-1 levels on the surface of HCV-specific T cells, supporting the necessity of ongoing antigenic stimulation of T cells for maintenance of PD-1 expression. These results support the idea that PD-1 expression on T cells specific for nonescaped epitopes contributes to viral persistence and suggest that PD-1 blockade may alter the outcome of HCV infection.

Hepatitis C virus immune escape via exploitation of a hole in the T cell repertoire.

Hepatitis C virus (HCV) infection frequently persists despite eliciting substantial virus-specific immune responses. Thus, HCV infection provides a setting in which to investigate mechanisms of immune escape that allow for viral persistence. Viral amino acid substitutions resulting in decreased MHC binding or impaired Ag processing of T cell epitopes reduce Ag density on the cell surface, permitting evasion of T cell responses in chronic viral infection. Substitutions in viral epitopes that alter TCR contact residues frequently result in escape, but via unclear mechanisms because such substitutions do not reduce surface presentation of peptide-MHC complexes and would be expected to prime T cells with new specificities. We demonstrate that a known in vivo HCV mutation involving a TCR contact residue significantly diminishes T cell recognition and, in contrast to the original sequence, fails to effectively prime naive T cells. This mutant epitope thus escapes de novo immune recognition because there are few highly specific cognate TCR among the primary human T cell repertoire. This example is the first on viral immune escape via exploitation of a "hole" in the T cell repertoire, and may represent an important general mechanism of viral persistence.

HIV-1 MN Env 15-mer peptides better detect HIV-1 specific CD8 T cell responses compared with consensus subtypes B and M group 15-mer peptides.

OBJECTIVE: To compare the ability of three Env (15-mer) peptide sets derived from the HIV-1 MN, the subtype B consensus, and the group M consensus to detect HIV-1 specific interferon (IFN)-gamma responses in HIV-1 subtype B infected subjects. METHODS: Peripheral blood mononuclear cells were obtained from 17 HIV-1 subtype B seropositive and 5 HIV-1 seronegative subjects. Peptide matrices comprising each peptide set were used in IFN-gamma Elispot assays to screen for T cell epitopes. Following matrix deconvolution, individual peptides were analyzed by IFN-gamma intracellular cytokine-staining to confirm and characterize the responding cells. RESULTS: HIV specific IFN-gamma responses were detected in 17 of 17 HIV-1 seropositive and none of 5 HIV-1 seronegative subjects by Elispot. Within the 17 HIV-1 seropositives, 16, 14, and 11 subjects responded to MN, B consensus, and group M env peptides, respectively. Responses were confirmed by intracellular cytokine analysis in 14 subjects and were in the CD3CD8 compartment. Cross-recognition of 'equivalent' peptides (i.e., peptides mapping to the same sequence region from the three peptide sets) was observed in 9 of 17 subjects. Peptide set specific responses to individual peptides were also observed; 11, 1, and 1 subjects demonstrated peptide set specific responses to MN, B consensus, and consensus group M, respectively. CONCLUSION: MN derived Env peptides were better able to detect HIV-1 specific CD8 T cell responses, many of which were not detectable by the equivalent clade or group consensus peptides. No single peptide set detected all the IFN-gamma responses within an individual. These results demonstrate the importance of reagent selection for monitoring of HIV responses in HIV-1 infected individuals and subsequently vaccine recipients.

HIV type 1-specific inter- and intrasubtype cellular immune responses in HIV type 1-infected Ugandans.

Investigations concerning the extent and nature of subtype-specific and intersubtype immune responses in HIV-1-infected persons are necessary for the development of appropriate candidate vaccines. In the cross-sectional study described here, 26 HIV-1-positive Ugandan patients were tested for their ability to mount HIV antigen-specific cellular immune responses. Subjects were infected with either HIV-1 subtypes A, C, or D. Recombinant vaccinia virus (rVV)-based and peptide-based enzyme-linked immunospot (Elispot) assays were used to evaluate HIV-1-specific gamma-interferon (IFN-gamma) cellular responses. rVV expressing gag, pol, or env proteins derived from HIV-1 subtypes A, B, and D were evaluated for their ability to induce whole HIV-1-protein-specific IFN-gamma responses in 14 patients. A panel of previously identified HLA class I-restricted peptides based on representative sequences from HIV-1 subtypes A, B, C, and D and restricted through HLA-A2, -A29, -B42, -B53, and -B57 alleles were used to evaluate the presence of HIV-1-peptide-specific T cells in 19 patients. Using rVV, 27 of a possible 38 subtype-specific responses (71%) and 56 of a possible 110 intersubtype responses (51%) were observed. When appropriate peptides were used 18 of 39 (46.2%) subtype-specific and 13 of 39 (33.3%) intersubtype responses were observed. Peptide responses were higher quantitatively than those seen when rVV were used. In 7 patients, both rVV and specific peptides were evaluated; in 3 of 7 individuals, global responses were seen despite a lack of measurable HLA-restricted peptide-specific responses demonstrating the need to evaluate a broader range of HIV-specific immune responses.

Effect of human immunodeficiency virus (HIV) type 1 envelope subtypes A and D on disease progression in a large cohort of HIV-1-positive persons in Uganda.

The effect of human immunodeficiency virus (HIV) type 1 envelope subtypes A and D on disease progression was investigated in 1045 adults in Uganda. At enrollment and every 6 months, a clinical history, examination, and laboratory investigations that included CD4 cell counts were done. HIV-1 envelope subtype was assessed mainly by peptide serology supplemented by heteroduplex mobility assay and DNA sequencing. A multivariate analysis of survival was performed to assess the prognostic value of HIV-1 subtype on death. A marginal general linear model also determined the effect of subtype on CD4 cell count during follow-up. Subtype D was associated with faster progression to death (relative risk, 1.29; 95% confidence interval, 1.07-1.56; P=.009) and with a lower CD4 cell count during follow-up (P=.001), compared with subtype A, after adjusting for CD4 cell count at enrollment. In Africa, envelope subtype D is associated with faster disease progression, compared with subtype A.