Prevention of respiratory virus transmission by resident memory CD8+ T cells

An ideal vaccine both attenuates virus growth and disease in infected individuals and reduces the spread of infections in the population, thereby generating herd immunity. Although this strategy has proved successful by generating humoral immunity to measles, yellow fever and polio, many respiratory viruses evolve to evade pre-existing antibodies1. One approach for improving the breadth of antiviral immunity against escape variants is through the generation of memory T cells in the respiratory tract, which are positioned to respond rapidly to respiratory virus infections2-6. However, it is unknown whether memory T cells alone can effectively surveil the respiratory tract to the extent that they eliminate or greatly reduce viral transmission following exposure of an individual to infection. Here we use a mouse model of natural parainfluenza virus transmission to quantify the extent to which memory CD8+ T cells resident in the respiratory tract can provide herd immunity by reducing both the susceptibility of acquiring infection and the extent of transmission, even in the absence of virus-specific antibodies. We demonstrate that protection by resident memory CD8+ T cells requires the antiviral cytokine interferon-γ (IFNγ) and leads to altered transcriptional programming of epithelial cells within the respiratory tract. These results suggest that tissue-resident CD8+ T cells in the respiratory tract can have important roles in protecting the host against viral disease and limiting viral spread throughout the population.

Examining effector functions of lung CD8+ tissue resident memory T cells in humans

Due to their position in the lung tissue, CD8+ tissue resident memory T cells (TRM) act as sentinels of the respiratory tract that rapidly respond to, and mediate protection against, respiratory viruses. In mice, TRM have been shown to mediate protection at barrier sites by producing cytokines, chemokines, and performing cell lysis. In the lungs specifically, our lab has shown that influenza-specific CD8+ TRM rapidly produce IFNγ, but airway TRM are poorly cytolytic in mice. In humans, less is known about the effector functions of virus-specific CD8+ TRM in the lungs, and thus this study seeks to fill that gap in knowledge. Using cells from healthy human lungs, we first identified and quantified the frequency of antigen-specific cells in our lung donors by performing intracellular cytokine staining (IFNγ+) and activation induced marker assays (CD137+ CD25+). Then, by performing a series of in vitro peptide stimulation and cytokine neutralization experiments, we investigated which cytokines are produced by lung CD8+ TRM, and how those cytokines impact local innate and epithelial cells. Initial results show that, when stimulated with their cognate antigen, lung CD8+ TRM produce cytokines that directly activate innate immune cells. Results of this study suggests that human CD8+ TRM in the lungs act to rapidly reprogram local immune cells, and these data will ultimately help us understand how CD8+ TRM fit into the overall immune response to respiratory viruses.

Supported by grants from the NIH/NHLBI (R35 HL150803) and by NIH/NIAD through the Centers of Excellence for Influenza Research and Response (75N93019R00028).

Lineage analysis defines subpopulations of human lung tissue-resident memory CD8+ T cells

Tissue resident memory T cells (TRM) are important for local immunity and recall responses. In contrast to effector and central memory T cells, TRM remain in the tissues and do not circulate throughout the body. CD69 and CD103 expression are distinguishing markers of TRM cells, although TRM cells expressing only one marker, or absent of both markers, have been described, suggesting further heterogeneity beyond these markers. Many of the phenotypic characteristics and transcriptional properties of TRM cells have been defined in animal models, where in vivo labeling can be used to define tissue residency. Therefore, a deeper understanding of what defines human TRM cells and their molecular heterogeneity is necessary. To address this, single-cell multi-omics data of memory CD8+ T cells isolated from human lungs that have been phenotypically subsetted into CD69+, CD69+CD103+, CD69-CD103-, and naive cells were collected and analyzed by scATAC-seq and scRNA-seq approaches. A lineage analysis of these data identified multiple distinct lineages of TRM cells in human lungs. From this, we defined the genes that drive each lineage through their differentiation program, the variable transcription factor motifs that distinguish each lineage terminal state, and estimate the rate of differentiation as the cells transition. In identifying these subpopulations, we can begin to understand the heterogeneity of TRM cells in humans on a molecular level.

Supported by a grant from the NIH/NIAID (75N93019R00028) and a grant from the NIH/NHLBI (R35 HL150803)

Resident Memory CD8+ T cells in the respiratory tract prevent transmission of respiratory viruses

Tissue-resident memory CD8+ T cells (TRM) in the respiratory tract reduce viral replication and limit pathology following respiratory virus infections. In infection with heterosubtypic influenza viruses, where pre-existing antibodies does not proved sterilizing immunity, TRM are critical for protection. However, in addition to protecting the host against disease vaccine programs are also designed to limit viral spread in a population. Due to the lack of an animal model to study the effect of TRM on transmission through longitudinal tracking, and with immunological parameters easily identified and manipulated available, this hasn’t been studied before. To solve these issues, we used a luciferase expressing Sendai virus, a natural mouse parainfluenza virus that readily transmits via the aerosol and contact routes, as well as a recombinant influenza virus expressing the immunodominant Sendai NP324-332/Kb epitope to generate SenNP+ memory CD8+ T cells. By utilizing IVIS imaging to non-invasively measure Sendai virus infection over time, we found that mice with pre-existing SenNP+ TRM in the respiratory system don’t transmit Sendai virus to naïve mice when co-housed. In contrast, mice with pre-existing circulating SenNP+ effector memory CD8+ T cells, but no TRM, failed to prevent transmission of Sendai virus to naïve mice when co-housed. In addition, we found that the prevention of transmission was dependent on the production of IFNγ. These findings demonstrates notably that antigen specific lung TRM contributes to herd immunity by preventing respiratory virus transmission. This underscores the importance, and potential, of TRMs generated by vaccines for protection against respiratory viruses.

Long-term alterations in brain and behavior after postnatal Zika virus infection in infant macaques

Zika virus (ZIKV) infection has a profound impact on the fetal nervous system. The postnatal period is also a time of rapid brain growth, and it is important to understand the potential neurobehavioral consequences of ZIKV infection during infancy. Here we show that postnatal ZIKV infection in a rhesus macaque model resulted in long-term behavioral, motor, and cognitive changes, including increased emotional reactivity, decreased social contact, loss of balance, and deficits in visual recognition memory at one year of age. Structural and functional MRI showed that ZIKV-infected infant rhesus macaques had persistent enlargement of lateral ventricles, smaller volumes and altered functional connectivity between brain areas important for socioemotional behavior, cognitive, and motor function (e.g. amygdala, hippocampus, cerebellum). Neuropathological changes corresponded with neuroimaging results and were consistent with the behavioral and memory deficits. Overall, this study demonstrates that postnatal ZIKV infection in this model may have long-lasting neurodevelopmental consequences.

Systemic HIV and SIV latency reversal via non-canonical NF-κB signalling in vivo

Long-lasting, latently infected resting CD4+ T cells are the greatest obstacle to obtaining a cure for HIV infection, as these cells can persist despite decades of treatment with antiretroviral therapy (ART). Estimates indicate that more than 70 years of continuous, fully suppressive ART are needed to eliminate the HIV reservoir1. Alternatively, induction of HIV from its latent state could accelerate the decrease in the reservoir, thus reducing the time to eradication. Previous attempts to reactivate latent HIV in preclinical animal models and in clinical trials have measured HIV induction in the peripheral blood with minimal focus on tissue reservoirs and have had limited effect2-9. Here we show that activation of the non-canonical NF-κB signalling pathway by AZD5582 results in the induction of HIV and SIV RNA expression in the blood and tissues of ART-suppressed bone-marrow-liver-thymus (BLT) humanized mice and rhesus macaques infected with HIV and SIV, respectively. Analysis of resting CD4+ T cells from tissues after AZD5582 treatment revealed increased SIV RNA expression in the lymph nodes of macaques and robust induction of HIV in almost all tissues analysed in humanized mice, including the lymph nodes, thymus, bone marrow, liver and lung. This promising approach to latency reversal-in combination with appropriate tools for systemic clearance of persistent HIV infection-greatly increases opportunities for HIV eradication.

Postnatal Zika virus infection is associated with persistent abnormalities in brain structure, function, and behavior in infant macaques

The Zika virus (ZIKV) epidemic is associated with fetal brain lesions and other serious birth defects classified as congenital ZIKV syndrome. Postnatal ZIKV infection in infants and children has been reported; however, data on brain anatomy, function, and behavioral outcomes following infection are absent. We show that postnatal ZIKV infection of infant rhesus macaques (RMs) results in persistent structural and functional alterations of the central nervous system compared to age-matched controls. We demonstrate ZIKV lymphoid tropism and neurotropism in infant RMs and histopathologic abnormalities in the peripheral and central nervous systems including inflammatory infiltrates, astrogliosis, and Wallerian degeneration. Structural and resting-state functional magnetic resonance imaging (MRI/rs-fMRI) show persistent enlargement of lateral ventricles, maturational changes in specific brain regions, and altered functional connectivity (FC) between brain areas involved in emotional behavior and arousal functions, including weakened amygdala-hippocampal connectivity in two of two ZIKV-infected infant RMs several months after clearance of ZIKV RNA from peripheral blood. ZIKV infection also results in distinct alterations in the species-typical emotional reactivity to acute stress, which were predicted by the weak amygdala-hippocampal FC. We demonstrate that postnatal ZIKV infection of infants in this model affects neurodevelopment, suggesting that long-term clinical monitoring of pediatric cases is warranted.

Analytical Treatment Interruption after Short-Term Antiretroviral Therapy in a Postnatally Simian-Human Immunodeficiency Virus-Infected Infant Rhesus Macaque Model

To achieve long-term viral remission in human immunodeficiency virus (HIV)-infected children, novel strategies beyond early antiretroviral therapy (ART) will be necessary. Identifying clinical predictors of the time to viral rebound upon ART interruption will streamline the development of novel therapeutic strategies and accelerate their evaluation in clinical trials. However, identification of these biomarkers is logistically challenging in infants, due to sampling limitations and the potential risks of treatment interruption. To facilitate the identification of biomarkers predicting viral rebound, we have developed an infant rhesus macaque (RM) model of oral simian-human immunodeficiency virus (SHIV) SHIV.CH505.375H.dCT challenge and analytical treatment interruption (ATI) after short-term ART. We used this model to characterize SHIV replication kinetics and virus-specific immune responses during short-term ART or after ATI and demonstrated plasma viral rebound in 5 out of 6 (83%) infants. We observed a decline in humoral immune responses and partial dampening of systemic immune activation upon initiation of ART in these infants. Furthermore, we monitored SHIV replication and rebound kinetics in infant and adult RMs and found that both infants and adults demonstrated equally potent virus-specific humoral immune responses. Finally, we validated our models by confirming a well-established correlate of the time to viral rebound, namely, the pre-ART plasma viral load, as well as identified additional potential humoral immune correlates. Thus, this model of infant ART and viral rebound can be used and further optimized to define biomarkers of viral rebound following long-term ART as well as to preclinically assess novel therapies to achieve a pediatric HIV functional cure.IMPORTANCE Novel interventions that do not rely on daily adherence to ART are needed to achieve sustained viral remission for perinatally infected children, who currently rely on lifelong ART. Considering the risks and expense associated with ART interruption trials, the identification of biomarkers of viral rebound will prioritize promising therapeutic intervention strategies, including anti-HIV Env protein therapeutics. However, comprehensive studies to identify those biomarkers are logistically challenging in human infants, demanding the need for relevant nonhuman primate models of HIV rebound. In this study, we developed an infant RM model of oral infection with simian-human immunodeficiency virus expressing clade C HIV Env and short-term ART followed by ATI, longitudinally characterizing the immune responses to viral infection during ART and after ATI. Additionally, we compared this infant RM model to an analogous adult RM rebound model and identified virologic and immunologic correlates of the time to viral rebound after ATI.

Students with Low Vision Describe Their Visual Impairments and Visual Functioning

In the study reported here, the responses to a survey that was designed to determine the knowledge of their visual impairment of 51 students with low vision were analyzed. Although the students described their visual weaknesses and strengths, they had limited knowledge of, and difficulty communicating about, the medical aspects of their impairments.

Characterization of a newly established human pancreatic carcinoma cell line, UK Pan-1

BACKGROUND

A highly tumorigenic cell line designated as UK Pan-1 was established in a surgically removed human pancreatic adenocarcinoma and characterized as having many of the genotypic and phenotypic alterations commonly found in pancreatic tumors.

METHODS

The cell line was characterized by its morphology, growth rate in monolayer culture and soft agar, tumorigenicity in nude mice, and chromosomal analysis. Furthermore, the status of p53, Ki-ras mutation and transforming growth factor (TGF)-/receptor expression were determined. The characteristics of UK Pan-1 were compared with those of other commonly used pancreatic carcinoma cell lines.

RESULTS

Quiescent UK Pan-1 cells could be stimulated to proliferate in growth factor free nutrient media, indicating a growth factor independent phenotype. UK Pan- 1 cells grew in soft agar and rapidly formed tumors in nude mice. This cell line possesses a mutation at codon 12 of the c-Ki-ras-2 gene that is commonly found in pancreatic carcinoma. Fluorescence in situ hybridization showed that two alleles of p53 tumor suppressor gene were present in UK Pan-1. However, sequencing analysis revealed a mutation in one allele at exon 8, codon 273 (G to A; Arg to His). Additional growth assays indicated that the cell line was insensitive to negative growth regulation induced by exogenous TGF-beta. Molecular analysis of the TGF-beta signaling pathway showed that UK Pan-1 did not express appreciable levels of the TGF-beta receptor type I, II, or III mRNAs, but did express DPC4 mRNA. Karyotype analysis revealed an 18q21 deletion indicating a possible loss of heterozygosity for DPC4, as well as other chromosomal deletions and rearrangements.

CONCLUSIONS

This study indicates that UK Pan-1 is a highly tumorigenic cell line possessing a molecularly complex pattern of mutations that may be used as a model to further the understanding of the mechanisms responsible for the development of pancreatic carcinoma.

In search of the good: narrative reasoning in clinical practice

Based on ethnographic work among North American occupational therapists, I compare two forms of everyday clinical talk. One, "chart talk," conforms to normative conceptions of clinical rationality. The second, storytelling, permeates clinical discussions but has no formal status as a vehicle for clinical reasoning. I argue that both modes of discourse provide avenues for reasoning about clinical problems. However, these discourses construct very different clinical objects and different phenomena to reason about. Further, the clinical problems created through storytelling point toward a more radically distinct conception of rationality than the one underlying biomedicine as it is formally conceived. Clinical storytelling is more usefully understood as a mode of Aristotle's "practical rationality" than the technical rationality of modern (enlightenment) conceptions of reasoning.

Metaphor and meaning in a clinical interview

This study examined the narrative features of 20 life histories gathered from psychiatric patients with the Occupational Performance History Interview. The aim was to identify how narrative features were present in the patient interview responses and to illustrate how such narrative features can be located. We found that the patients organized their interview responses with deep metaphors that served to "emplot," or give meaning to, the life story. This article illustrates how patients used the deep metaphors to both circumscribe and frame possible solutions to the problems in their lives. Deep metaphors are consistent, recurring images of a life story that give coherence to, and aid in, the interpretation of the events of that life. Moreover, we explored how metaphors can be located in patient life histories and their implications for occupational therapy.

In vitro cytolytic activity of lymphocytes from tumor-draining lymph nodes is associated with increased numbers of CD8+ cells and increased cytokine production

A murine footpad tumor model was used to determine the cytotoxic activity, tumor specificity, phenotypic profile, and cytokine production of stimulated cells from draining lymph nodes (DLN). Popliteal DLN from 5-day-old P-815 footpad tumors were stimulated with 10(-7) M phorbol 12, 13-dibutyrate +5 x 10(-7) M ionomycin for 16 hr and cultured in IL-2 (20 units/ml) for 7 or 14 days without autologous tumor. Most cells in both groups were CD3+ (93% at Day 7, 99% at Day 14); however, the percentage of CD8+ cells increased as the cell population matured in the presence of low-dose IL-2. On Day 7, the phenotypic profile was 62% CD4+ and 29% CD8+, whereas on Day 14 it was 16% CD4+ and 81% CD8+. Similarly, in vitro cytokine production increased with time in culture. After 7 days, the level of tumor necrosis factor-alpha (TNF-alpha) was 220 pg/mL and the interferon-gamma (IF-gamma) production was 150 pg/ml. At Day 14 the TNF level had increased to 500 pg/ml, and IF production had increased to 350 pg/ml. These increases in the CD8+ population and in cytokine production correlated with the increase in the percentage of target cells killed by the DLN cells. Cytolytic activity against P-815 was only 13% on Day 7 but 39% on Day 14. Neither group of effector cells (Day 7 or Day 14) had any cytolytic activity against the syngeneic tumor cell line L-1210, demonstrating the tumor specificity of the DLN cells. We describe a model for generating tumor-specific cytotoxic T-cells that have significant cytokine production, which may account for previously described in vivo activity.

Proliferation-associated nucleolar antigen P120: a prognostic marker in node-negative breast cancer

BACKGROUND

P120 is a nucleolar proliferation antigen found in rapidly dividing cells and in a variety of malignancies.

METHODS

Our purpose was to determine whether P120 expression is a prognostic factor for patients with node-negative breast cancer by testing pathologic material from 90 patients for P120 immunoreactivity, histologic grade, and estrogen receptors.

RESULTS

P120 was detected in 52 of the 90 specimens (58%). Node-negative cancer patients with tumors that did not express the P120 antigen had a significantly better overall survival rate than node-negative cancer patients with tumors that did express P120 (92% vs 69%; p = 0.035). Histologic studies indicated that 36 tumors were grade I, 28 were grade II, and 26 were grade III. The presence of P120 correlated significantly with the nuclear grade of the tumor: 73% of grade III tumors, 64% of grade II tumors, and 42% of grade I tumors stained positive for P120 (p = 0.033). The correlation between nuclear grade and overall survival rate was also significant (grade 1, 94%; grade II, 79%; grade III, 58%); (p = 0.003). No significant correlation was found between P120 expression and estrogen receptors. Multivariate analysis shows that P120 expression and histologic grade together are the strongest predictors of survival.

CONCLUSIONS

The biologic marker P120 may play an important role in determining which patients with node-negative cancer will benefit most from adjuvant therapy.

The terrible adventure of rehabilitation

Friendship with patients, caregivers are taught during their professional training, is to be avoided. Yet the capacity for friendship--to be "a person who emerges in her personhood and not simply as a professional"--may be crucial to effective therapy.

Volition as narrative: understanding motivation in chronic illness

This paper expands the current concept of volition in the Model of Human Occupation. The present version views personal causation, values, and interests as traits that determine choices to engage in occupations. Through a detailed investigation of the life histories of two persons with psychiatric disorders, this paper illustrates how volition is embedded in a personal narrative. Two features of narratively organized volition are highlighted: (a) how narrative places decisions and actions within a plot, thus giving them meaning in the context of a whole life, and (b) how the personal narrative motivates the person by serving as a context for choosing and action. Thus, the paper illustrates how persons seek to narrate their lives and live their life narratives.

Oncology and narrative time

Oncologists encounter the uncertainty of time horizons in their patients' lives. Although American oncologists are given a cultural mandate to instill hope in the therapeutic narratives they create with patients, uncertainty leads them to expressions of time without horizons or of time with highly foreshortened horizons as they seek to create for patients an experience of immediacy rather than of chronology. The distinctiveness of the American pattern is highlighted through comparison with Japanese exemplar cases and stories of therapeutic practices in oncology. Concepts drawn from narrative analysis of temporality and the construction of the therapeutic plot are employed.

The concept of therapeutic 'emplotment'

This paper considers the narrative structure of clinical action. I argue that clinical encounters involve clinician and patient in the creation and negotiation of a plot structure within clinical time. This clinical plot gives meaning to particular therapeutic actions by placing them within a larger therapeutic story. No therapeutic plot is completely pre-ordained, however. Improvisation and revision are necessary to its creation. In making a case for the narrative construction of lived time, of narratives that are created before they are told, this paper departs from the predominant mode of narrative analysis within medical anthropology that has focused on narrative discourse. Therapeutic emplotment is concretely considered through an interpretation of a single case, a clinical interaction between an occupational therapist and a head-injured patient.

Incorporation of ethnographic methods in occupational therapy assessment

Many constructs of interest to occupational therapists can only be studied through qualitative methods. Such constructs include meaning of activity or the illness experience and the context in which these occur. The purpose of this paper is to describe how ethnographic methods used in research can be generalized and applied to clinical practice. Ethnography is compared with other qualitative research approaches and a model clinical ethnographic assessment process is described.

Coumarin (1,2-benzopyrone) enhances DR and DQ antigen expressions by peripheral blood mononuclear cells in vitro

Coumarin (1,2-benzopyrone) is a natural substance that appears to have some clinical activity against renal cell carcinoma and malignant melanoma. Preliminary evidence from in vitro and in vivo studies suggests that coumarin possesses immunomodulatory activity. It was reported previously that coumarin therapy resulted in augmented DR antigen expression by peripheral blood monocytes in cancer patients. The purpose of the present study was to examine the effects of coumarin on DR and DQ antigen expression by normal donor peripheral blood mononuclear cells in vitro. Using monoclonal antibody labeling techniques and FACS analysis, it was shown that both DR and DQ antigen expression by peripheral blood mononuclear cells were enhanced over controls after 48 hours of exposure to coumarin. While monocytes normally express these antigens, enhanced expression is consistent with an activated state. These results support the hypothesis that coumarin acts, at least in part, through immune augmentation.

What is clinical reasoning?

This paper offers a concept of clinical reasoning that differs from many of the traditional definitions of clinical reasoning in occupational therapy and the health professions in general. Here, clinical reasoning in occupational therapy is described as a largely tacit, highly imagistic, and deeply phenomenological mode of thinking. It is argued that clinical reasoning involves more than the ability to offer explicit reasons that justify clinical decisions because it is also based on tacit understanding and habitual knowledge gained through experience. Clinical reasoning also involves more than a simple application of theory, particularly theory as understood in the natural sciences, because complex clinical tasks often require that the therapist improvise a treatment approach that addresses the unique meaning of disability as it relates to a particular patient.

The narrative nature of clinical reasoning

Narrative reasoning is a central mode of clinical reasoning in occupational therapy. Therapists reason narratively when they are concerned with disability as an illness experience, that is, with how a physiological condition is affecting a person's life. In this paper, narrative reasoning is contrasted with propositional reasoning, and two kinds of narrative thinking are examined. The first is the use of narrative as a mode of speech that can be contrasted with biomedical discourse, in which disability is framed as physical pathology. The second involves the creation rather than the telling of stories. Therapists try to "emplot" therapeutic encounters with patients, that is, to help create a therapeutic story that becomes a meaningful short story in the larger life story of the patient.

Anthropology, occupational therapy, and action research

This paper describes the research process and methodology used in the American Occupational Therapy Association/American Occupational Therapy Foundation Clinical Reasoning Study. This study examined the clinical reasoning of occupational therapists through a 2-year ethnography of therapists at one hospital site. The research was innovative in several important respects. One important innovation was a combined ethnographic and action research design that involved collaboration between the research team and those therapists being studied. Therapists who were research subjects became actively involved in examining and reflecting on their own practice through group analysis of videotaped sessions with clients. One outcome of this action research component was that the study served as both a research and a staff development project.