A multiplex PCR assay for the differentiation of complex reveals high rates of mixed-lineage tuberculosis infections among patients in Ghana.

In low-resource settings with high tuberculosis (TB) burdens, lack of rapid diagnostic methods for detection and differentiation of complex (MTBC) is a major challenge affecting TB management. This study utilized comparative genomic analyses of MTBC lineages; , Lineages 5/6 and to identify lineage-specific genes. Primers were designed for the development of a Multiplex PCR assay which was successful in differentiating the MTBC lineages.

Sestrins induce natural killer function in senescent-like CD8 T cells.

Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8 T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27CD28CD8 T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands.

The association between loneliness, social isolation and inflammation: A systematic review and meta-analysis.

The review synthesised evidence examining the association between a. loneliness with inflammation and b. social isolation with inflammation in adults aged 16 or older from the general population.

Dietary supplementation with inulin-propionate ester or inulin improves insulin sensitivity in adults with overweight and obesity with distinct effects on the gut microbiota, plasma metabolome and systemic inflammatory responses: a randomised cross-over trial.

Objective: To investigate the underlying mechanisms behind changes in glucose homeostasis with delivery of propionate to the human colon by comprehensive and coordinated analysis of gut bacterial composition, plasma metabolome and immune responses.

Design: Twelve non-diabetic adults with overweight and obesity received 20 g/day of inulin-propionate ester (IPE), designed to selectively deliver propionate to the colon, a high-fermentable fibre control (inulin) and a low-fermentable fibre control (cellulose) in a randomised, double-blind, placebo-controlled, cross-over design. Outcome measurements of metabolic responses, inflammatory markers and gut bacterial composition were analysed at the end of each 42-day supplementation period.

The effects of dietary supplementation with inulin and inulin-propionate ester on hepatic steatosis in adults with non-alcoholic fatty liver disease.

The short chain fatty acid (SCFA) propionate, produced through fermentation of dietary fibre by the gut microbiota, has been shown to alter hepatic metabolic processes that reduce lipid storage. We aimed to investigate the impact of raising colonic propionate production on hepatic steatosis in adults with non-alcoholic fatty liver disease (NAFLD). Eighteen adults were randomized to receive 20 g/d of an inulin-propionate ester (IPE), designed to deliver propionate to the colon, or an inulin control for 42 days in a parallel design.

Quantitative Characterization of the T Cell Receptor Repertoire of Naïve and Memory Subsets Using an Integrated Experimental and Computational Pipeline Which Is Robust, Economical, and Versatile.

The T cell receptor (TCR) repertoire can provide a personalized biomarker for infectious and non-infectious diseases. We describe a protocol for amplifying, sequencing, and analyzing TCRs which is robust, sensitive, and versatile. The key experimental step is ligation of a single-stranded oligonucleotide to the 3' end of the TCR cDNA.

Progenitor cells are mobilized by acute psychological stress but not beta-adrenergic receptor agonist infusion.

Objectives: Stimuli that activate the sympathetic nervous system, such as acute psychological stress, rapidly invoke a robust mobilization of lymphocytes into the circulation. Experimental animal studies suggest that bone marrow-derived progenitor cells (PCs) also mobilize in response to sympathetic stimulation. Here we tested the effects of acute psychological stress and brief pharmacological β-adrenergic (βAR) stimulation on peripheral PC numbers in humans.

Blockade of PD-1 or p38 MAP kinase signaling enhances senescent human CD8(+) T-cell proliferation by distinct pathways.

Immune enhancement is desirable in situations where decreased immunity results in increased morbidity. We investigated whether blocking the surface inhibitory receptor PD-1 and/or p38 MAP kinase could enhance the proliferation of the effector memory CD8(+) T-cell subset that re-expresses CD45RA (EMRA) and exhibits characteristics of senescence, which include decreased proliferation and telomerase activity but increased expression of the DNA damage response related protein γH2AX. Blocking of both PD-1 and p38 MAPK signaling in these cells enhanced proliferation and the increase was additive when both pathways were inhibited simultaneously in both young and old human subjects.

Multifunctional cytomegalovirus (CMV)-specific CD8(+) T cells are not restricted by telomere-related senescence in young or old adults.

Antigen-specific multifunctional T cells that secrete interferon-γ, interleukin-2 and tumour necrosis factor-α simultaneously after activation are important for the control of many infections. It is unclear if these CD8(+) T cells are at an early or late stage of differentiation and whether telomere erosion restricts their replicative capacity. We developed a multi-parameter flow cytometric method for investigating the relationship between differentiation (CD45RA and CD27 surface phenotype), function (cytokine production) and replicative capacity (telomere length) in individual cytomegalovirus (CMV) antigen-specific CD8(+) T cells.

p38 signaling inhibits mTORC1-independent autophagy in senescent human CD8⁺ T cells.

T cell senescence is thought to contribute to immune function decline, but the pathways that mediate senescence in these cells are not clear. Here, we evaluated T cell populations from healthy volunteers and determined that human CD8+ effector memory T cells that reexpress the naive T cell marker CD45RA have many characteristics of cellular senescence, including decreased proliferation, defective mitochondrial function, and elevated levels of both ROS and p38 MAPK. Despite their apparent senescent state, we determined that these cells secreted high levels of both TNF-α and IFN-γ and showed potent cytotoxic activity.

New advances in CMV and immunosenescence.

Immunosenescence, defined as the age-associated dysregulation and dysfunction of the immune system, is characterized by impaired protective immunity and decreased efficacy of vaccines. An increasing number of immunological, clinical and epidemiological studies suggest that persistent Cytomegalovirus (CMV) infection is associated with accelerated aging of the immune system and with several age-related diseases. However, current evidence on whether and how human CMV (HCMV) infection is implicated in immunosenescence and in age-related diseases remains incomplete and many aspects of CMV involvement in immune aging remain controversial.

Age-associated increase of low-avidity cytomegalovirus-specific CD8+ T cells that re-express CD45RA.

The mechanisms regulating memory CD8(+) T cell function and homeostasis during aging are unclear. CD8(+) effector memory T cells that re-express CD45RA increase considerably in older humans and both aging and persistent CMV infection are independent factors in this process. We used MHC class I tetrameric complexes that were mutated in the CD8 binding domain to identify CMV-specific CD8(+) T cells with high Ag-binding avidity.

Varicella zoster-specific CD4+Foxp3+ T cells accumulate after cutaneous antigen challenge in humans.

We investigated the relationship between varicella zoster virus (VZV)-specific memory CD4(+) T cells and CD4(+)Foxp3(+) regulatory T cells (Tregs) that accumulate after intradermal challenge with a VZV skin test Ag. VZV-specific CD4(+) T cells were identified with a MHC class II tetramer or by intracellular staining for either IFN-γ or IL-2 after Ag rechallenge in vitro. VZV-specific T cells, mainly of a central memory (CD45RA(-)CD27(+)) phenotype, accumulate at the site of skin challenge compared with the blood of the same individuals.

Differing HLA types influence inhibitory receptor signalling in CMV-specific CD8+ T cells.

The dysregulated immune response to CMV constitutes a major force driving T cell immunosenescence and growing evidence suggests that it is not a benign virus in old age. We show here that the PD-1/L pathway defines a reversible defect in CMV specific CD8(+) T cell proliferative responses in both young and old individuals. More specifically, highly differentiated CD45RA(+)CD27(-) CMV-specific CD8(+) T cells exhibit a proliferative deficit compared their central and effector memory counterparts, which is reversed following PD-L blockade.

CMV and Immunosenescence: from basics to clinics.

Alone among herpesviruses, persistent Cytomegalovirus (CMV) markedly alters the numbers and proportions of peripheral immune cells in infected-vs-uninfected people. Because the rate of CMV infection increases with age in most countries, it has been suggested that it drives or at least exacerbates "immunosenescence". This contention remains controversial and was the primary subject of the Third International Workshop on CMV & Immunosenescence which was held in Cordoba, Spain, 15-16th March, 2012.

Properties of end-stage human T cells defined by CD45RA re-expression.

Persistent viral infections, inflammatory syndromes and ageing all induce the accumulation of highly differentiated CD45RA re-expressing memory T cells. These cells increase during ageing, especially in individuals who are infected with cytomegalovirus (CMV). These cells have decreased proliferative capacity, increased activation of senescence signalling pathways and greater susceptibility to apoptosis in vitro.

Report from the second cytomegalovirus and immunosenescence workshop.

The Second International Workshop on CMV & Immunosenescence was held in Cambridge, UK, 2-4th December, 2010. The presentations covered four separate sessions: cytomegalovirus and T cell phenotypes; T cell memory frequency, inflation and immunosenescence; cytomegalovirus in aging, mortality and disease states; and the immunobiology of cytomegalovirus-specific T cells and effects of the virus on vaccination. This commentary summarizes the major findings of these presentations and references subsequently published work from the presenter laboratory where appropriate and draws together major themes that were subsequently discussed along with new areas of interest that were highlighted by this discussion.

Reversible senescence in human CD4+CD45RA+CD27- memory T cells.

Persistent viral infections and inflammatory syndromes induce the accumulation of T cells with characteristics of terminal differentiation or senescence. However, the mechanism that regulates the end-stage differentiation of these cells is unclear. Human CD4(+) effector memory (EM) T cells (CD27(-)CD45RA(-)) and also EM T cells that re-express CD45RA (CD27(-)CD45RA(+); EMRA) have many characteristics of end-stage differentiation.

Mobilization of gammadelta T lymphocytes in response to psychological stress, exercise, and beta-agonist infusion.

The mobilization of cytotoxic lymphocytes, such Natural Killer (NK) cells and CD8(+) T cells, during stress and exercise is well documented in humans. However, humans have another cytotoxic lymphocyte subset that has not been studied in this context: the Gamma Delta (gammadelta) T lymphocyte. These cells play key roles in immune processes including the elimination of bacterial infection, wound repair and delayed-type hypersensitivity reactions.

Acute exercise mobilises CD8+ T lymphocytes exhibiting an effector-memory phenotype.

An acute bout of exercise evokes mobilisation of lymphocytes into the bloodstream, which can be largely attributed to increases in CD8+ T lymphocytes (CD8TLs) and natural killer (NK) cells. Evidence further suggests that, even within these lymphocyte subsets, there is preferential mobilisation of cells that share certain functional and phenotypic characteristics, such as high cytotoxicity, low proliferative ability, and high tissue-migrating potential. These features are characteristic of effector-memory CD8TL subsets.