Physician and Trainee Experiences With Patient Bias.

Importance: As the clinical workforce becomes more diverse, physicians encounter patients who demean them based on social characteristics. Little is known about physicians' perspectives on these encounters and their effects. This knowledge would help develop policies and best practices for institutions and training programs. Objective: To describe the range and importance of encounters with biased patients and the barriers and facilitators to effective responses. Design, Setting, and Participants: This qualitative study recruited convenience samples of hospitalist attending physicians, internal medicine residents, and medical students from 3 campuses affiliated with 1 academic medical center. Data were collected from 50 individuals within 13 focus groups from May 9 through October 15, 2018. Focus groups were conducted using open-ended probes, audiotaped, and transcribed. Participants used their own definition of biased patient behavior. Each transcript was independently coded by at least 2 investigators. Data were analyzed from May 2018 through February 2019. Main Outcomes and Measures: Major themes associated with types of encounter, importance to the participant, and barriers and facilitators to effective responses were abstracted through the constant comparative approach. Results: Overall, 50 individuals (11 hospitalists, 26 residents, and 13 students) participated; 24 (48%) were nonwhite. At total of 26 participants (52%) identified as women; 22 (44%), as men; and 2 (4%), as gender nonconforming. Reports of biased behavior ranged from patient refusal of care and explicit racist, sexist, or homophobic remarks to belittling compliments or jokes. Targeted physicians reported an emotional toll that included exhaustion, self-doubt, and cynicism. Nontargeted bystanders reported moral distress and uncertainty about how to respond. Participant responses ranged from withdrawal from clinical role to a heightened determination to provide standard of care. Barriers to effective responses included lack of skills, insufficient support from senior colleagues and the institution, and perception of lack of utility associated with responding. Participants expressed a need for training on dealing with biased patients and for clear institutional policies to guide responses. Conclusions and Relevance: In this qualitative study of physicians and medical students, encounters with demeaning patients ranged from refusal of care to belittling jokes and were highly challenging and painful. Addressing biased patient behavior will require a concerted effort from medical schools and hospitals to create policies and trainings conducive to a clinical environment that respects the diversity of patients and physicians alike.

Differential impact of PD-1 and/or interleukin-10 blockade on HIV-1-specific CD4 T cell and antigen-presenting cell functions.

UNLABELLED: Antigen persistence in chronic infections and cancer upregulates inhibitory networks, such as the PD-1 and interleukin-10 (IL-10) pathways, that impair immunity and lead to disease progression. These pathways are attractive targets for immunotherapy, as demonstrated by recent clinical trials of PD-1/PD-L1 blockade in cancer patients. However, in HIV-1 infection not all subjects respond to inhibition of either pathway and the mechanistic interactions between these two networks remain to be better defined. Here we demonstrate that in vitro blockade of PD-L1 and/or IL-10Rα results in markedly different profiles of HIV-1-specific CD4 T cell restoration. Whereas PD-L1 blockade leads to balanced increase in gamma interferon (IFN-γ), IL-2, and IL-13 secretion, IL-10Rα blockade preferentially restores IFN-γ production. In viremic subjects, combined PD-L1/IL-10Rα blockade results in a striking 10-fold increase in IFN-γ secretion by HIV-1-specific CD4 T cells that is not observed in subjects with spontaneous (elite controllers) or therapy-induced control of viral replication. In contrast to the dramatic increase in IFN-γ production, concurrent blockade has a marginal additive effect on IL-2 production, IL-13 secretion, and HIV-1-specific CD4 T cell proliferation. IFN-γ produced by Thelper cells upregulates PD-L1, HLA I/II, and IL-12 expression by monocytes. The effect of combined blockade on IFN-γ was dependent on reciprocal reinforcement through IL-12. These studies provide crucial information on the different immunoregulatory qualities of PD-1 and IL-10 in progressive disease and link exhausted virus-specific CD4 T cells and monocytes in the regulation of IFN-γ and IL-12 secretion. IMPORTANCE: Infection with HIV results in most people in uncontrolled viral replication and progressive weakening of the body defenses. In the absence of antiviral therapy, this process results in clinical disease, or AIDS. An important reason why HIV continues to multiply is that a population of white blood cells called CD4 T cells that targets the virus fails to work properly. At least part of this impairment is under the control of inhibitory mechanisms that can be blocked to improve the function of these CD4 T cells. In this report, we show that blocking one or two of the molecules involved, called PD-1 and IL-10, has different effects on the individual functions of these cells and that one is strongly improved. We investigate how these effects are caused by interactions between CD4 T cells and antigen-presenting cells. These observations can have implications for new therapeutic approaches in HIV infection.

High-dimensional immunomonitoring models of HIV-1-specific CD8 T-cell responses accurately identify subjects achieving spontaneous viral control.

UNLABELLED: The development of immunomonitoring models to determine HIV-1 vaccine efficacy is a major challenge. Studies suggest that HIV-1­specific CD8 T cells play a critical role in subjects achieving spontaneous viral control (HIV-1 controllers) and that they will be important in immune interventions. However, no single CD8 T-cell function is uniquely associated with controller status and the heterogeneity of responses targeting different epitopes further complicates the discovery of determinants of protective immunity. In the present study, we describe immunomonitoring models integrating multiple functions of epitope-specific CD8 T cells that distinguish controllers from subjects with treated or untreated progressive infection. Models integrating higher numbers of variables and trained with the least absolute shrinkage and selection operator (LASSO) variant of logistic regression and 10-fold cross-validation produce "diagnostic tests" that display an excellent capacity to delineate subject categories. The test accuracy reaches 75% area under the receiving operating characteristic curve in cohorts matched for prevalence of protective alleles. Linear mixed-effects model analyses show that the proliferative capacity, cytokine production, and kinetics of cytokine secretion are associated with HIV-1 control. Although proliferative capacity is the strongest single discriminant, integrated modeling of different dimensions of data leverages individual associations. This strategy may have important applications in predictive model development and immune monitoring of HIV-1 vaccine trials. KEY POINTS: Immune monitoring models integrating multiple functions of HIV-1-specific CD8 T cells distinguish controllers from subjects with progressive HIV-1 infection. This strategy may have important applications in predictive model development and immune monitoring of HIV-1 vaccine trials.

Evidence for a unique species-specific hypersensitive epitope in Mycobacterium tuberculosis derived cord factor.

Presensitization with Mtb-derived trehalose 6,6'-dimycolate (TDM; cord factor) followed by challenge with the same glycolipid species resulted in elicitation of stronger inflammatory responses than when mice were similarly challenged with M. bovis-derived TDM. Mice presensitized to the homologous Mtb-derived TDM demonstrated cachexic over a 6 day period, whereas similarly presensitized mice challenged with the M. bovis-derived TDM, or with emulsion control, did not experience weight loss. Examination of inflammatory responses demonstrated increased lung histopathology in the Mtb-derived TDM challenged group, evidenced by severe tissue disruption, cellular influx, vascular occlusion and lymphocytic cuffing, and endothelial cell damage. Histological analysis demonstrated that lung pathology in the M. bovis challenged group was strikingly similar to that of the acute model challenge. Examination of proinflammatory mediators also showed findings consistent with histological manifestation, with significantly elevated TNF-α and IL-1ß, as well as IFN-γ, in the homologous TDM challenged group relative to all other groups. Overall, these findings indicate a difference in hypersensitive immune responses to TDM derived from different mycobacterial strains. Development of specific adaptive immune responses to the Mtb-derived TDM were demonstrated that had limited cross-reactivity to that of M. bovis, thus strongly suggesting the presence of hypersensitive epitopes exclusive to Mtb TDM not present on M. bovis-derived TDM.

Elite controllers with low to absent effector CD8+ T cell responses maintain highly functional, broadly directed central memory responses.

Analyses of the breadth and specificity of virus-specific CD8(+) T cell responses associated with control of HIV have largely relied on measurement of cytokine secretion by effector T cells. These have resulted in the identification of HIV elite controllers with low or absent responses in which non-T-cell mechanisms of control have been suggested. However, successful control of HIV infection may be associated with central memory T cells, which have not been consistently examined in these individuals. Gag-specific T cells were characterized using a peptide-based cultured enzyme-linked immunosorbent spot assay (ELISpot). Peripheral blood mononuclear cells from HIV elite controllers (n = 10), progressors (n = 12), and antiretroviral-treated individuals (n = 9) were cultured with overlapping peptides for 12 days. Specificity was assessed by tetramer staining, functional features of expanded cells were assessed by cytokine secretion, and virus inhibition and phenotypic characteristics were assessed by cell sorting and coculture assays. After peptide stimulation, elite controllers showed a greater number of previously undetectable (new) responses compared to progressors (P = 0.0008). These responses were highly polyfunctional, with 64.5% of responses having 3 to 5 functions. Expandable epitope-specific CD8(+) T cells from elite controllers had strong virus inhibitory capacity and predominantly displayed a central memory phenotype. These data indicate that elite controllers with minimal T cell responses harbor a highly functional, broadly directed central memory T cell population that is capable of suppressing HIV in vitro. Comprehensive examination of this cell population could provide insight into the immune responses associated with successful containment of viremia.

Responsiveness of HIV-specific CD4 T cells to PD-1 blockade.

Defining the T helper functions impaired by programmed death-1 (PD-1) is crucial for understanding its role in defective HIV control and determining the therapeutic potential of targeting this inhibitory pathway. We describe here the relationships among disease stage, levels of PD-1 expression, and reversibility of CD4 T-cell impairment. PD-L1 blockade in vitro enhanced HIV-specific production of Th0 (IL-2), Th1 (IFN-γ), Th2 (IL-13), and TFH (IL-21) cytokines by CD4 T cells. PD-L1 blockade caused an early increase in cytokine transcription and translation that preceded cell proliferation. Although the impact of PD-L1 blockade on cytokine expression and, to a lesser extent, cell proliferation was associated with markers of disease progression, restoration of cytokine secretion was also observed in most subjects with undetectable viremia. PD-L1 blockade restored cytokine secretion in both PD-1intermediate and PD-1high sorted CD4 T-cell subsets. Compared with PD-1high HIV-specific CD8 T cells, PD-1high HIV-specific CD4 T cells showed lower expression of the inhibitory molecules CD160 and 2B4, demonstrating marked differences in expression of inhibitory receptors between T-cell subsets. These data show that PD-1 impairs HIV-specific T helper responses both by limiting expansion of these cells and by inhibiting effector functions of multiple differentiated CD4 T-cell subsets.

Mosaic HIV-1 Gag antigens can be processed and presented to human HIV-specific CD8+ T cells.

Polyvalent mosaic HIV immunogens offer a potential solution for generating vaccines that can elicit immune responses against genetically diverse viruses. However, it is unclear whether key T cell epitopes can be processed and presented from these synthetic Ags and recognized by epitope-specific human T cells. In this study, we tested the ability of mosaic HIV immunogens expressed by recombinant, replication-incompetent adenovirus serotype 26 vectors to process and present major HIV clade B and clade C CD8 T cell epitopes in human cells. A bivalent mosaic vaccine expressing HIV Gag sequences was used to transduce PBMCs from 12 HIV-1-infected individuals from the United States and 10 HIV-1-infected individuals from South Africa; intracellular cytokine staining, together with tetramer staining, was used to assess the ability of mosaic Gag Ags to stimulate pre-existing memory responses compared with natural clade B and C vectors. Mosaic Gag Ags expressed all eight clade B epitopes tested in 12 United States subjects and all 5 clade C epitopes tested in 10 South African subjects. Overall, the magnitude of cytokine production induced by stimulation with mosaic Ags was comparable to clade B and clade C Ags tested, but the mosaic Ags elicited greater cross-clade recognition. Additionally, mosaic Ags induced HIV-specific CD4 T cell responses. Our studies demonstrate that mosaic Ags express major clade B and clade C viral T cell epitopes in human cells, as well as support the evaluation of mosaic HIV-1 vaccines in humans.