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Background— The number of CD4 + CD28 null (CD28 null ) T cells, a unique subset of T lymphocytes with proinflammatory and cell-lytic phenotype, increases markedly in patients with acute coronary syndrome (ACS). ACS patients harboring high numbers of CD28 null T cells have increased risk of recurrent severe acute coronary events and unfavorable prognosis. The mechanisms that govern the increase in CD28 null T cells in ACS remain elusive. We investigated whether apoptosis pathways regulating T-cell homeostasis are perturbed in CD28 null T cells in ACS. Methods and Results— We found that CD28 null T cells in ACS were resistant to apoptosis induction via Fas-ligation or ceramide. This was attributable to a dramatic reduction in proapoptotic molecules Bim, Bax, and Fas in CD28 null T cells, whereas antiapoptotic molecules Bcl-2 and Bcl-xL were similar in CD28 null and CD28 + T cells. We also show that Bim is phosphorylated in CD28 null T cells and degraded by the proteasome. Moreover, we demonstrate for the first time that proteasomal inhibition restores the apoptosis sensitivity of CD28 null T cells in ACS. Conclusions— We show that CD28 null T cells in ACS harbor marked defects in molecules that regulate T-cell apoptosis, which tips the balance in favor of antiapoptotic signals and endows these cells with resistance to apoptosis. We demonstrate that the inhibition of proteasomal activity allows CD28 null T cells to regain sensitivity to apoptosis. A better understanding of the molecular switches that control the apoptosis sensitivity of CD28 null T cells may reveal novel strategies for targeted elimination of these T cells in ACS patients.

Management of the pregnant surgical patient is challenging. The surgical procedure is usually postponed until the postpartum period, although this may not be possible in emergency situations. This article highlights the optimal management of the pregnant woman requiring ear nose and throat surgery.

OBJECTIVE Analyze the presentation and evolution of chronic suppurative otitis media (CSOM) in children with cochlear implants (CI) and explore the merit of early intervention. STUDY DESIGN Retrospective patient review. SETTING Tertiary referral hospital and cochlear implant programme. PATIENTS Children with a CI who developed CSOM. INTERVENTION Tympanoplasty. MAIN OUTCOME MEASURES Disease control, recurrence of cholesteatoma, cochlear implant preservation. RESULTS Eight children fit our inclusion criteria with a mean follow up of 8 years. Onset of CSOM symptoms was observed on an average of 5 years after implantation (range, 2-13 yr) and led to surgical intervention in an average of 15.6 months following symptom onset. Cholesteatoma was found in four of the eight patients. Of these, one patient underwent a subtotal petrosectomy and explantation with reimplantation at the same stage but the reimplant failed to function and was explanted subsequently. One patient was initially managed by a canal wall up mastoidectomy and explantation but went on to require subtotal petrosectomy and labyrinthectomy for recurrent disease. One patient underwent a subtotal petrosectomy with explantation and is awaiting a reimplantation. The fourth patient had limited disease around the electrodes that was excised without compromising the implant. In the group of patients with CSOM without cholesteatoma, one underwent an explantation due to recurrent ear infections and a subsequent cartilage tympanoplasty for a retracted eardrum. The remaining three patients underwent successful excision of retraction pockets and repair of eardrums using cartilage with the implant in situ. A mean follow up of 2 years after the implant preservation surgeries shows good functioning of the CI. CONCLUSION Early recognition of CSOM is paramount in patients with CI as delay in treatment can result in the infection spreading via the cochleostomy resulting in loss of the cochlea. Recurrent ear infections in an implanted ear should prompt early examination to exclude the presence of middle ear disease, which may require anesthesia in a young child.

Head and neck cancers (HNC) are aggressive tumours. Tumour-specific T cells are frequently identified in patients with cancer, although they fail to control tumour progression. A family of proteins called co-stimulatory receptors regulate the function of T cells and may account for T cell dysfunction in cancer. Our aim was to characterise co-stimulatory receptors on T cells in HNC patients to identify novel targets for immunotherapy.Peripheral blood mononuclear cells were isolated from HNC patients and healthy controls and the expression of co-stimulatory (OX40, 4-1BB, ICOS) and co-inhibitory (CTLA-4, PD1) receptors was analysed on CD4(+) and CD8(+) T cells using flow cytometry.We found that the levels of co-stimulatory receptors OX40 and 4-1BB were significantly lower on CD4(+) T cells from HNC patients. This was more pronounced in locally advanced tumours (T3/T4) compared to early carcinomas (T1/T2). PD-1 levels were higher on CD8(+) T cells in HNC patients compared to controls. Human papilloma virus (HPV)-specific CD8(+) T cells appeared to be more affected than Influenza-specific T cells.Our results indicate that expression of co-stimulatory receptors on T cells from HNC patients is imbalanced with a preponderance of inhibitory signals, and reduction of stimulatory signals, especially in advanced disease. Restoring this balance could improve T cell therapy outcomes in HNC.

The 129-derived Sle16 is a susceptibility locus for systemic autoimmunity when present on the C57BL/6 (B6) background. Genetic analysis of a (129×B6)F2 cross identified a region from the B6 chromosome 3 (Sle18) with positive linkage to antinuclear Abs. In this study, we have generated a B6 congenic strain harboring the 129 allele of Sle18 and intercrossed this line with the lupus-prone B6.129-Sle16 strain. The presence of the 129-Sle18 allele in the B6.129-Sle16Sle18 double congenic mice suppressed the development of Sle16-mediated autoantibody production and ameliorated the renal pathology. The 129-Sle18 locus rectified the B cell abnormalities detected in the B6.129-Sle16 mice, such as the reduction in the percentage of marginal zone B and B1a cells and the increased number of germinal centers. The B6.129-Sle16Sle18 spleens still displayed an increased percentage of activated T and B cells. However, in the B6.129-Sle16Sle18 strain the percentage of naive T cells was equivalent to that in B6.129-Sle18 and B6 mice and these cells showed a reduced proliferative response to anti-CD3 stimulation compared with B6.129-Sle16 T cells. There was a significant increase in the percentage of CD4+FoxP3+regulatory T cells in all congenic strains. These cells had normal regulatory function when tested in vitro. Thus, 129-Sle18 represents a novel, non-MHC lupus-suppressor locus probably operating as a functional modifier of B cells that, in combination with other factors, leads to lupus resistance. Further characterization of this locus will help to uncover the immune mechanism(s) conferring protection against lupus.

Complement activation is known to have deleterious effects on organ transplantation. On the other hand, the complement system is also known to have an important role in regulating immune responses. The balance between these two opposing effects is critical in the context of transplantation. Here, we report that female mice deficient in C1q (C1qa(-/-)) or C3 (C3(-/-)) reject male syngeneic grafts (HY incompatible) at an accelerated rate compared with WT mice. Intranasal HY peptide administration, which induces tolerance to syngeneic male grafts in WT mice, fails to induce tolerance in C1qa(-/-) or C3(-/-) mice. The rejection of the male grafts correlated with the presence of HY D(b)Uty-specific CD8(+) T cells. Consistent with this, peptide-treated C1qa(-/-) and C3(-/-) female mice rejecting male grafts exhibited more antigen-specific CD8(+)IFN-gamma(+) and CD8(+)IL-10(+) cells compared with WT females. This suggests that accumulation of IFN-gamma- and IL-10-producing T cells may play a key role in mediating the ongoing inflammatory process and graft rejection. Interestingly, within the tolerized male skin grafts of peptide-treated WT mice, IFN-gamma, C1q and C3 mRNA levels were higher compared to control female grafts. These results suggest that C1q and C3 facilitate the induction of intranasal tolerance.

Dendritic cells (DCs) are known to produce C1q, the initiator of the classical complement pathway. We demonstrate that murine DCs deficient in C1q (C1qa−/−) are poorer than wild-type (WT) DCs at eliciting the proliferation and Th1 differentiation of antigen-specific T cells. These defects result from decreased production of IL-12p70 by C1qa−/− DCs and impaired expression of costimulatory molecules CD80 and CD86 in response to CD40 ligation. The defective production of IL-12p70 and the reduced expression of CD80 and CD86 by C1qa−/− DCs were specifically mediated via CD40 ligation, as normal levels of IL-12p70 and CD80/86 were observed after ligation of Toll-like receptors (TLRs) on C1qa−/− DCs. CD40 ligation on C1qa−/− DCs, but not TLR ligation, results in decreased phosphorylation of p38 and ERK1/2 kinases. A strong colocalization of CD40 and C1q was observed by confocal microscopy upon CD40 ligation (but not TLR ligation) on DCs. Furthermore, human DCs from 2 C1q-deficient patients were found to have impaired IL-12p70 production in response to CD40L stimulation. Our novel data suggest that C1q augments the production of IL-12p70 by mouse and human DCs after CD40 triggering and plays important roles in sustaining the maturation of DCs and guiding the activation of T cells.

Head and neck cancer (HNC) constitutes an important proportion of cancers worldwide. These are aggressive tumours, and survival rates have remained poor in spite of advances in surgical techniques, radiotherapy and chemotherapy. Interestingly, certain subtypes of HNC are associated with a better prognosis. Sixty per cent of oropharyngeal cancers associate with the oncogenic human papilloma virus (HPV; subtypes 16 and 18; Venuti et al, 2004). Of note, this cohort of patients has a better disease-free survival than the patients who do not express the viral protein (Ang et al, 2010). The reasons underlying this are not known, and further understanding of the biology of these tumours is necessary in order to develop new therapeutic options. It is well known that tumour growth depends on the establishment of a robust vascular supply to support the oxygen and nutrient requirements of cancer cells. This formation of blood vessel network or angiogenesis also acts as a conduit to allow the spread of cancer cells to the rest of the body (metastases) and thereby promote aggressive tumour progression (Folkman et al, 1989; Hanahan and Folkman, 1996). Vessel turnover in healthy tissue is maintained in the steady state by interactions between molecules that promote angiogenesis (pro-angiogenesis factors) and those that inhibit it (anti-angiogenesis factors; Hanahan and Weinberg, 2011). Tumours exploit this phenomenon and can produce a wide variety of pro-angiogenesis factors to promote their own growth, and the levels of these factors in the tumour microenvironment could determine the outcome of cancer therapy. Indeed, anti-angiogenesis therapies in the form of antibodies (for example, anti-vascular endothelial growth factor (VEGF) antibody) or recombinant proteins (for example, endostatin) are being actively used in the treatment of solid tumours (Cohen et al, 2009; Ye et al, 2014). The aim of this work was to dissect the impact of prognostic factors such as p16, tumour size and nodal status on the angiogenesis profile of HNC. To this purpose, we studied the circulating levels of a panel of 11 angiogenesis factors in patients with HNC and correlated the levels with known prognostic factors including the p16 status. In addition, we explored the effect of the p16 status on the cellular source of angiogenesis factors in the tumour tissue.

Dendritic cells (DC) are key components of innate and adaptive immune responses. Plasmacytoid DC (PDC) are a specialized DC subset that produce high amounts of type I interferons in response to microbes. High mobility group box 1 protein (HMGB1) is an abundant nuclear protein, which acts as a potent pro-inflammatory factor when released extracellularly. We show that HMGB1 leaves the nucleus of maturing PDC following TLR9 activation, and that PDC express on the plasma membrane the best-characterized receptor for HMGB1, RAGE. Maturation and type I IFN secretion of PDC is hindered when the HMGB1/RAGE pathway is disrupted. These results reveal HMGB1 and RAGE as the first known autocrine loop modulating the maturation of PDC, and suggest that antagonists of HMGB1/RAGE might have therapeutic potential for the treatment of systemic human diseases.

High mobility group box 1 (HMGB1) is an abundant and conserved nuclear protein that is released by necrotic cells and acts in the extracellular environment as a primary proinflammatory signal. In this study we show that human dendritic cells, which are specialized in Ag presentation to T cells, actively release their own HMGB1 into the extracellular milieu upon activation. This secreted HMGB1 is necessary for the up-regulation of CD80, CD83, and CD86 surface markers of human dendritic cells and for IL-12 production. The HMGB1 secreted by dendritic cells is also required for the clonal expansion, survival, and functional polarization of naive T cells. Using neutralizing Abs and receptor for advanced glycation end product-deficient (RAGE−/−) cells, we demonstrate that RAGE is required for the effect of HMGB1 on dendritic cells. HMGB1/RAGE interaction results in downstream activation of MAPKs and NF-κB. The use of an ancient signal of necrosis, HMGB1, by dendritic cells to sustain their own maturation and for activation of T lymphocytes represents a profitable evolutionary mechanism.

We performed endoscopic resection on six patients who had inverted papillomas of the nasal cavity. Disease was completely cleared in four patients after a single procedure, while two others—both of whom had bilateral disease—required repeat surgery. At follow-up, which ranged from 6 months to 5 years, all patients were disease-free. We believe that endoscopic surgery is ideally suited for the treatment of appropriately selected patients who have limited disease and who are likely to adhere conscientiously to a regular follow-up program.

Objectives:Dissect the impact of human papillomavirus (HPV) on angiogenesis in head and neck cancers (HNSCC).Methods:We analyzed 18 newly diagnosed HNSCC patients and controls. HPV tumor status was ascertained by p16 staining. Eleven pro- and anti-angiogenic factors were quantified in sera using a multiplex assay. Angiogenic factors were analyzed in the tumor tissue using immunohistochemistry.Results:We found that circulating levels of anti-angiogenic factor endostatin were higher in all HNSCC patients compared with healthy subjects irrespective of HPV status. Notably, we detected higher levels of the proangiogenic factors angiopoetin-1 and vascular endothelial growth factor (VEGF) in the circulation of HPV-negative patients compared with patients with HPV-positive tumors. Interestingly, levels of thrombospondin-2, an antiangiogenic factor, were lower in the circulation of patients with HPV-positive compared with HPV-negative tumors and healthy controls. We next analyzed these angiogenic factors in the tu...

Definition Autoimmune inner ear disease (AIED) is characterised by a rapidly progressive, often fluctuating, bilateral sensorineural hearing loss over a period of weeks to months. It is an uncommon disease accounting for less than 1% of all cases of hearing impairment or dizziness. The diagnosis is often missed and this impacts on the prognosis as the condition responds well to steroids and immunosuppressants if recognised early. Lacuna in knowledge No useful specific test for autoimmunity affecting the inner ear exists. Objective of study To gather evidence regarding cochlin in AIED. Methodology Systematic review of human studies and animal experimental studies on inner ear antigens was undertaken. Search strategy We searched MEDLINE (1965–2012), and Pubmed for relevant studies. A combination of key words for inner ear, autoimmunity (autoimmune, immune mediated) and cochlin were used. Results A number of antigens have been implicated in autoimmune inner ear disease. Cochlin is a major component of the extracellular matrix in the inner ear and a promising candidate. We present evidence in literature on the role of this protein in the pathogenesis of autoimmune inner ear disease.

Rationale: Patients with acute coronary syndrome (ACS) predisposed to recurrent coronary events have an expansion of a distinctive T-cell subset, the CD4 + CD28 null T cells. These cells are highly inflammatory and cytotoxic in spite of lacking the costimulatory receptor CD28, which is crucial for optimal T cell function. The mechanisms that govern CD4 + CD28 null T cell function are unknown. Objective: Our aim was to investigate the expression and role of alternative costimulatory receptors in CD4 + CD28 null T cells in ACS. Methods and Results: Expression of alternative costimulatory receptors (inducible costimulator, OX40, 4–1BB, cytotoxic T lymphocyte associated antigen-4, programmed death-1) was quantified in CD4 + CD28 null T cells from circulation of ACS and stable angina patients. Strikingly, in ACS, levels of OX40 and 4-1BB were significantly higher in circulating CD4 + CD28 null T cells compared to classical CD4 + CD28 + T lymphocytes. This was not observed in stable angina patients. Furthermore, CD4 + CD28 null T cells constituted an important proportion of CD4 + T lymphocytes in human atherosclerotic plaques and exhibited high levels of OX40 and 4-1BB. In addition, the ligands for OX40 and 4-1BB were present in plaques and also expressed on monocytes in circulation. Importantly, blockade of OX40 and 4-1BB reduced the ability of CD4 + CD28 null T cells to produce interferon-γ and tumor necrosis factor-α and release perforin. Conclusions: Costimulatory pathways are altered in CD4 + CD28 null T cells in ACS. We show that the inflammatory and cytotoxic function of CD4 + CD28 null T cells can be inhibited by blocking OX40 and 4-1BB costimulatory receptors. Modulation of costimulatory receptors may allow specific targeting of this cell subset and may improve the survival of ACS patients.

Objectives Simple investigations like white cell count (WCC) and C-reactive protein (CRP) may help to improve the accuracy of diagnosis in paediatric appendicitis. We evaluated the diagnostic accuracy of WCC and CRP for the severity of acute appendicitis in children. Design Cross-sectional study. Setting This study was conducted on all children who underwent open appendectomy from January 2007 to December 2008 at a District General Hospital. Data regarding demographics, WCC, CRP, histology and postoperative complications were analysed. Participants All children who underwent open appendectomy during the study period. Main outcome measures Diagnostic accuracy of WCC and CRP for simple acute appendicitis and a perforated appendix. Results Out of 204 patients, 112 (54.9%) were girls. At surgery, appendix was grossly inflamed in 175 of which 32 had perforation. Histology revealed simple acute appendicitis in 135 (66.2%) and gangrenous appendicitis in 32 (15.7%). The rest were normal. The duration of symptoms, temperature, length of stay, WCC and CRP were significantly worse in the perforated group ( P value Conclusion Accuracy of WCC is higherthan CRP for diagnosing simple acute appendicitis. The combined sensitivity of WCC and CRP increases for simple acute appendicitis as well as a perforated appendix.

Extract: Survival has always been a challenge in nature and fast adaptation is the key. To adapt to new situations during evolution, cells learned to reuse available molecules for different purposes. One example of a molecule recruited from an extant cellular pathway into new functions is the high mobility group box 1 (HMGB1) protein. Over the years, HMGB1 has been known by many names (amphoterin, differentiation enhancing factor, sulphoglucuronyl carbohydrate binding protein-1, p30) and relatively recently has been discovered to have a double identity from a functional point of view. When it resides in the nucleus, HMGB1 binds and bends the DNA helix facilitating the formation of protein complexes (multiple proteins binding to the same stretch of DNA) that regulate nuclear biochemical transactions. Once outside the cell it acts as a potent signal of inflammation, which is a fast response set in motion following injury or infection. The inflammatory reaction is mediated by the innate immune system, which constitutes the first line of defense to tissue damage and microbial agents. Processes like elimination of dead cells, protection against invading microorganisms and tissue repair intersect at the level of innate immunity. We will summarize recently published data that point towards HMGB1 as a common signal of tissue injury and infection used by the innate immune system, and highlight its involvement in disease.

Background Pentraxin 3 (PTX3) and complement component C1q are humoral factors of innate immunity, produced at sites of inflammation, and are essential in immune defense against several microbes such as Aspergillus, which is commonly implicated in nasal polyposis. Methods PTX3 and C1q were measured in nasal polyp tissue, normal nasal mucosa, and serum of patients and healthy subjects. Immunohistochemistry for the two proteins was done on normal nasal mucosa and nasal polyps. In addition, PTX3 and C1q production from mononuclear cells from patients and healthy subjects was assessed. Results Normal nasal mucosa was found to have 100-fold higher levels of PTX3 compared with serum. No measurable local increase of PTX3 was observed in polyps compared with normal mucosa. Immunohistochemistry revealed PTX3 expression in the lining of blood vessels both within normal mucosa and nasal polyps. PTX3 also was present in mononuclear cells infiltrating nasal polyps. C1q levels were higher in polyps than in normal nasal mucosa. Conclusion High levels of PTX3 are present in normal nasal mucosa, suggesting a role in the maintenance of tissue homeostasis. Elevated C1q levels in nasal polyps might be indicative of an ongoing inflammatory response in the nasal mucosa in these patients.

Pentraxins (PTX) and complement belong to the humoral arm of the innate immune system and have essential functions in immune defense to microbes and in scavenging cellular debris. The prototypic long PTX, PTX3, and the first component of the classical complement pathway, C1q, are innate opsonins involved in the disposal of dying cells by phagocytes. Whether the interaction between various innate opsonins impacts on their function is not fully understood. We show here that characterized Toll-like receptor (TLR) ligands elicit the production of C1q and PTX3 by immature dendritic cells (DC). Moreover, these molecules bind to dying cells with similar kinetics, although they recognize different domains on the cell membranes. PTX3 binds in the fluid phase to C1q, decreasing C1q deposition and subsequent complement activation on apoptotic cells. C1q increases the phagocytosis of apoptotic cells by DC and the release of interleukin-12 in the presence of TLR4 ligands and apoptotic cells; PTX3 inhibits both events. Moreover, PTX3 inhibited the cross-presentation of the MELAN-A/melanoma antigen-reactive T cell 1 (MART-1) tumor antigen expressed by dying cells, even in the presence of C1q. These results suggest that interaction of C1q and PTX3 influences the clearance of apoptotic cells by DC. The coordinated induction by primary, proinflammatory signals of C1q and PTX3 and their reciprocal regulation during inflammation influences the clearance of apoptotic cells by antigen-presenting cells and possibly plays a role in immune homeostasis.

Pentraxins are soluble pattern recognition receptors with a dual role: protection against extracellular microbes and autoimmunity. The mechanisms by which they accomplish these tasks are not yet fully understood. Here we show that the prototypic long pentraxin PTX3 is specifically recruited at both sides of the phagocytic synapse between dendritic cells (DCs) and dying cells and remains stably bound to the apoptotic membranes (estimated half-time > 36 hours). Apoptotic cells per se influence the production of PTX3 by maturing DCs. When both microbial stimuli and dying cells are present, PTX3 behaves as a flexible adaptor of DC function, regulating the maturation program and the secretion of soluble factors. Moreover a key event associated with autoimmunity (ie, the cross-presentation of epitopes expressed by apoptotic cells to T cells) abates in the presence of PTX3, as evaluated using self, viral, and tumor-associated model antigens (vinculin, NS3, and MelanA/MART1). In contrast, PTX3 did not influence the presentation of exogenous soluble antigens, an event required for immunity against extracellular pathogens. These data suggest that PTX3 acts as a third-party agent between microbial stimuli and dying cells, contributing to limit tissue damage under inflammatory conditions and the activation of autoreactive T cells.

Two of the main challenges that eukaryotic multicellular organisms faced during evolution were to eliminate and replace dying cells and to cope with invading microorganisms. The innate immune system evolved to handle both tasks: to scavenge cellular debris and to form the first line of defence against microbes. In this review, we focus on high mobility group box 1 (HMGB1) protein as a common signal that alerts the innate immune system to excessive or deregulated cell death and to microbial invasion. HMGB1, which is well known nuclear protein, has revealed unexpected facets as an extracellular mediator. The role of HMGB1 as an endogenous molecule that facilitates immune responses and has an important role in tissue homeostasis and disease will be highlighted here.

Purpose Head and neck cancers (HNC) are aggressive tumours. Expression of Human Papilloma Virus (HPV)-derived protein p16 in HNC is known to correlate with a better prognosis than p16-negative tumours. Angiogenesis is an important factor in tumour progression. Our aim was to dissect the impact of HPV on angiogenic factors in HNC. Methods 18 newly diagnosed HNC patients and controls were analysed in this study. A panel of 11 pro- and anti-angiogenic factors was quantified in serum samples of HNC patients and controls using multiplex ELISA and correlated to the p16 expression in the tumour tissue. Tumour tissue was tested using immunohistochemistry for the expression of angiogenic factors and co-localisation performed to identify the predominant cellular source of angiogenic factors. Results All patients had higher circulating levels of the antiangiogenic factor endostatin compared to healthy donors. Interestingly, higher levels of the proangiogenic factors angiopoetin, placental growth factor (PlGF) and vascular endothelial growth factor (VEGF) were noted in patients who did not express p16 compared to those who did. Tumour associated macrophages appear to be a major cellular source of these angiogenic factors and work is underway to analyse the expression of angiogenic factors in HPV-positive and negative tumour tissue. Conclusions HNC patients that lack p16 expression have a different pattern of angiogenic factors with increased proangiogenic factors angiopoietin, PlGF and VEGF. This may confer a more aggressive phenotype to p16-negative tumours. Better understanding of the mechanisms by which HPV induces changes in tumour angiogenesis may guide the development of novel therapeutic targets.

We performed endoscopic resection on six patients who had inverted papillomas of the nasal cavity. Disease was completely cleared in four patients after a single procedure, while two others--both of whom had bilateral disease--required repeat surgery. At follow-up, which ranged from 6 months to 5 years, all patients were disease-free. We believe that endoscopic surgery is ideally suited for the treatment of appropriately selected patients who have limited disease and who are likely to adhere conscientiously to a regular follow-up program.

Aim: Atherosclerosis is now widely recognized as a disease with an underlying immune deregulation. Patients with coronary atherosclerosis that develop myocardial infarction (MI) have an expansion of a unique subset of T lymphocytes, the CD4+CD28null (CD28null) T cells, characterized by the lack of the CD28 co-stimulatory receptor. These cells have a pro-inflammatory and cell-lytic phenotype. Patients harbouring high numbers of CD28null T have increased risk of recurrent severe acute coronary events (i.e. MI) and unfavourable prognosis. Why CD28null T cells accumulate preferentially in patients with MI compared to patients with stable angina (SA) and healthy individuals is currently unknown. T cell homeostasis is maintained by elimination of unwanted T cells via apoptotic cell death. We hypothesized that apoptosis pathways that mediate elimination of T cells are dysregulated in CD28null T cells in patients with MI. Our aim was to investigate molecules involved in apoptosis regulation in CD28null T cells in patients with coronary atherosclerosis (MI and SA). Methods: Levels of pro-apoptotic (i.e. Fas, FasL, Bim and Bax) and anti-apoptotic (Bcl-2, Bcl-xL) proteins were measured in patients with MI (n=25) and SA patients (n=18) using flow-cytometry. Apoptosis sensitivity of CD28null T cells to the Fas-ligating antibody CH11 and C2-ceramide was measured with annexin-V and 7-AAD. Results: Pro-apoptotic molecules Fas, Bim and Bax were dramatically reduced on CD28null T cells in patients with MI, whilst anti-apoptotic molecules Bcl-2 and Bcl-xL were similar in CD28null and CD28+ T cells. Notably, CD28null T cells in patients with MI showed significantly lower Bim and Bax levels compared to CD28null T cells in SA patients. We found that CD28null T cells in MI patients were resistant to apoptosis induction via Fas-ligation or ceramide. Furthermore, we show that proteasomal inhibition restores apoptosis sensitivity of CD28null T cells in patients with MI. Conclusion: We show that CD28null T cells in patients with MI harbour marked defects in molecules that regulate T cell apoptosis, which tips the balance in favour of anti-apoptotic signals and endows these cells with resistance to apoptosis. Furthermore, we propose a novel mechanism that implicates the proteasome as a key regulator of apoptosis sensitivity of CD28null T cells in patients with MI. A better understanding of the molecular switches that control apoptosis sensitivity of CD28null T cells may reveal novel strategies for targeted elimination of these T cells in patients with coronary atherosclerosis.

Aim: T and B lymphocytes, the main cellular effectors of adaptive immunity, are deeply involved in the chronic inflammatory process that drives atherosclerosis. As the main source of antibodies, B cells were originally thought to be anti-atherogenic via production of neutralising antibodies against oxidised low density lipoprotein (LDL). Recent studies that depleted B lymphocytes in animal models of atherosclerosis have unravelled pro-atherogenic effects of conventional mature B2 B cells and protective roles for the innate B1a B-cell subset. Recently, B cells with regulatory function (Bregs) have also been identified in both animals and humans, but their role in atherosclerosis is currently unknown. Impairment of Bregs has been implicated in the pathogenesis of autoimmune disorders, but whether the same is true in atherosclerosis is yet to be determined. Our aim was to examine Bregs in patients with coronary atherosclerosis. Methods: Bregs were defined as CD19+CD24hiCD38hi B cells. The percentage and absolute number of Bregs was quantified in the circulation of patients with myocardial infarction (MI, n=60) and stable angina (SA, n=40), as well as in healthy subjects (n=30) using flow cytometry. The production of interleukin-10 (IL-10) by mature, memory and Breg cells was quantified by intracellular staining and flow cytometry. Results: We found a marked reduction in the percentage and absolute number of Bregs in patients with coronary atherosclerosis (MI and SA) compared to healthy subjects. No differences were noted in the percentage and absolute number of total B cells, mature and memory B cells in the study groups, suggesting a specific numerical deficit in Bregs in patients with coronary atherosclerosis. Furthermore, Bregs from patients with coronary atherosclerosis produced significantly less IL-10 in response to CpG and CD40L compared to Bregs from healthy subjects, while the production of IL-10 from mature and memory B cells was not impaired. We are now characterising the molecular mechanisms that underlie the defects in Bregs in patients with coronary atherosclerosis. Conclusion: Our data show for the first time that patients with coronary atherosclerosis harbour marked numerical and functional deficits in Breg cells that may tip the balance in favour of pro-inflammatory B and T lymphocytes. A better understanding of these defects may reveal novel targets for future therapies to quench the inflammatory process that drives atherosclerosis.

Retropharyngeal tubercular abscess is an uncommon cause of neck pain and dysphagia in the developed world. In this report, we describe an insidiously presenting retropharyngeal abscess treated successfully with intraoral aspiration and antitubercular chemotherapy. A 33-year-old female patient presented with neck pain and dysphagia. MRI revealed a large retropharyngeal abscess that was aspirated intraorally under local anaesthetic. Diagnosis of tuberculosis (TB) was confirmed by positive culture. The patient improved significantly following the initiation of antitubercular therapy. Retropharyngeal abscess is a recognised presentation of TB. The treatment is mainly medical with combination of specific antitubercular antibiotics, and aspiration may be sufficient for abscess drainage.