Analysis of host responses to Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa.

BACKGROUND: Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. METHODS: We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. RESULTS: There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST(-) and TST(+) contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST(+) contacts (LTBI) compared to TB and TST(-) contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. CONCLUSIONS: Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy trials

Identification of major factors influencing ELISpot-based monitoring of cellular responses to antigens from mycobacterium tuberculosis

A number of different interferon-c ELISpot protocols are in use in laboratories studying antigen-specific immune responses. It is therefore unclear how results from different assays compare, and what factors most significantly influence assay outcome. One such difference is that some laboratories use a short in vitro stimulation period of cells before they are transferred to the ELISpot plate; this is commonly done in the case of frozen cells, in order to enhance assay sensitivity. Other differences that may be significant include antibody coating of plates, the use of media with or without serum, the serum source and the number of cells added to the wells. The aim of this paper was to identify which components of the different ELISpot protocols influenced assay sensitivity and inter-laboratory variation. Four laboratories provided protocols for quantifying numbers of interferon-c spot forming cells in human peripheral blood mononuclear cells stimulated with Mycobacterium tuberculosis derived antigens. The differences in the protocols were compared directly. We found that several sources of variation in assay protocols can be eliminated, for example by avoiding serum supplementation and using AIM-V serum free medium. In addition, the number of cells added to ELISpot wells should also be standardised. Importantly, delays in peripheral blood mononuclear cell processing before stimulation had a marked effect on the number of detectable spot forming cells; processing delay thus should be minimised as well as standardised. Finally, a pre-stimulation culture period improved the sensitivity of the assay, however this effect may be both antigen and donor dependent. In conclusion, small differences in ELISpot protocols in routine use can affect the results obtained and care should be given to conditions selected for use in a given study. A pre-stimulation step may improve the sensitivity of the assay, particularly when cells have been previously frozen

Does an empathic pre-visit conversation with another team member improve perceived surgeon empathy?

Orthopedic surgeon specialists can help alleviate symptoms and reduce self-reported activity limitations by addressing stress, distress, and unhelpful cognitive biases regarding pain (e.g., “hurt equals harm”). But noticing mental and social health opportunities in specialty care can harm the patient-surgeon relationship. This study evaluated the ability of an empathic pre-visit conversation by another team member to improve the patient-surgeon relationship measured as perceived empathy. Factors associated with pain intensity, magnitude of self-reported activity limitations, symptoms of depression, and satisfaction with the surgeon were also studied. We enrolled 100 patients visiting an orthopedic surgeon for the first time. Prior to the visit with the surgeon, 50 patients met with another team member and had a pre-visit discussion about a sense of purpose and meaning in life, availability of loving relationships, and things that elicit laughter—a discussion intended to honor what matters most to an individual—and the other 50 patients did not. At the end of the visit we recorded perceived surgeon empathy, pain intensity, magnitude of self-reported activity limitations, symptoms of depression, and satisfaction with the surgeon. The pre-visit discussion did not affect perceived surgeon empathy (p=0.81), pain intensity (p=0.75), magnitude of self-reported activity limitations (p=0.63), symptoms of depression (p=0.46), or satisfaction with the surgeon (p=0.79). Patient experience with a surgeon does not benefit from a positive milieu created by a non-surgeon team member. Future studies can address relationship-building tactics used by the surgeon. Experience Framework This article is associated with the Patient, Family & Community Engagement lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this lens

Whole-blood transcriptomic signatures induced during immunization by chloroquine prophylaxis and Plasmodium falciparum sporozoites

A highly effective vaccine that confers sterile protection to malaria is urgently needed. Immunization under chemoprophylaxis with sporozoites (CPS) consistently confers high levels of protection in the Controlled Human Malaria infection (CHMI) model. To provide a broad, unbiased assessment of the composition and kinetics of direct ex vivo human immune responses to CPS, we profiled whole-blood transcriptomes by RNA-seq before and during CPS immunization and following CHMI challenge. Differential expression of genes enriched in modules related to T cells, NK cells, protein synthesis, and mitochondrial processes were detected in fully protected individuals four weeks after the first immunization. Non-protected individuals demonstrated transcriptomic changes after the third immunization and the day of treatment, with upregulation of interferon and innate inflammatory genes and downregulation of B-cell signatures. Protected individuals demonstrated more significant interactions between blood transcription modules compared to non-protected individuals several weeks after the second and third immunizations. These data provide insight into the molecular and cellular basis of CPS-induced immune protection from P. falciparum infection

Interleukin (IL)–12 and IL-23 Are Key Cytokines for Immunity against Salmonella in Humans

Patients with inherited deficiency of the interleukin (IL)–12/IL-23–interferon (IFN)–g axis show increased susceptibility to invasive disease caused by the intramacrophage pathogens salmonellae and mycobacteria. We analyzed data on 154 patients with such deficiency. Significantly more patients with IL-12/IL-23–component deficiency had a history of salmonella disease than did those with IFN-g–component deficiency. Salmonella disease was typically severe, extraintestinal, and caused by nontyphoidal serovars. These findings strongly suggest that IL-12/IL-23 is a key cytokine for immunity against salmonella in humans and that IL-12/IL-23 mediates this protective effect partly through IFN-g–independent pathways. Investigation of the IL-12/IL-23–IFN-g axis should be considered in patients with invasive salmonella disease

TB biomarkers, TB correlates and human challenge models: New tools for improving assessment of new TB vaccines

SummaryThe 4th Global Forum on TB Vaccines, convened in Shanghai, China, from 21 – 24 April 2015, brought together a wide and diverse community involved in tuberculosis vaccine research and development to discuss the current status of, and future directions for this critical effort. This paper summarizes the sessions on Biomarkers and Correlates, and Human Challenge Models. Summaries of all sessions from the 4th Global Forum are compiled in a special supplement of Tuberculosis. [August 2016, Vol 99, Supp S1, S1–S30]

Exploring the maturation of medical educators and their beliefs about teaching and learning: the value of a personal educational mission

This research explores the beliefs medical educators hold on being a teacher as well as on the process of teaching and learning, within the context of learning-centred education. It also explores the relationship between these two areas of inquiry, and how medical educators mature through developing their  beliefs about being a teacher over time.We conclude that maturation of medical educators’ beliefs about being a teacher can take place but is not self-evident, and seems to proceed through developmental stages of awareness of, successively, educational competencies, identity and mission. Awareness of a personal educational mission can reinforce and nurture an educator’s identity. Moreover, it gives meaning to an educator’s professional life and can fuel motivation for further development. This is an important explanation as to why educators who are aware of their educational mission have the most elaborate, learning-centred, beliefs about teaching and learning. Thus, supporting educators in becoming aware of and developing their educational mission is essential to foster learning-centred beliefs. This dissertation offers a deeper understanding of medical educators’ maturation, the factors influencing maturation, and its relationship with beliefs about teaching and learning, thereby contributing to the quality of learning of the next generation healthcare professionals.Nederlandse Vereniging voor Medisch Onderwijs (NVMO) ; J.E. Jurriaanse StichtingLUMC / Geneeskund

Potential of Mycobacterium tuberculosis resuscitation-promoting factors as antigens in novel tuberculosis sub-unit vaccines

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