The β-Carboline Harmine Has a Protective Immunomodulatory Role in Nonhealing Cutaneous Leishmaniasis

Cutaneous leishmaniasis affects 1 million people worldwide annually. Although conventional treatments primarily target the parasite, there is growing interest in host immune modulation. In this study, we investigated the impact of synthetic β-carboline harmine (ACB1801), previously shown to be immunoregulatory in cancer, on the pathology caused by a drug-resistant Leishmania major strain causing persistent cutaneous lesions. Exposure to ACB1801 in vitro had a modest impact on parasite burden within host macrophages. Moreover, it significantly increased major histocompatibility complex II and costimulatory molecule expression on infected dendritic cells, suggesting an enhanced immune response. In vivo, ACB1801 monotherapy led to a substantial reduction in lesion development and parasite burden in infected C57BL/6 mice, comparable with efficacy of amphotericin B. Transcriptomics analysis further supported ACB1801 immunomodulatory effects, revealing an enrichment of TNF-α, IFN-γ, and major histocompatibility complex II antigen presentation signatures in the draining lymph nodes of treated mice. Flow cytometry analysis confirmed an increased frequency (1.5×) of protective CD4+IFN-γ+TNF-α+ T cells and a decreased frequency (2×) in suppressive IL-10+FoxP3- T cells at the site of infection and in draining lymph nodes. In addition, ACB1801 downregulated the aryl hydrocarbon receptor signaling, known to enhance immunosuppressive cytokines. Thus, these results suggest a potential use for ACB1801 alone or in combination therapy for cutaneous leishmaniasis.

International development of a patient-centered core outcome set for assessing health-related quality of life in metastatic breast cancer patients

PURPOSE

For patients living with metastatic breast cancer (MBC), achieving best possible health-related quality of life, along with maximizing survival, is vital. Yet, we have no systemic way to determine if we achieve these goals. A Core Outcome Set (COS) that allows standardized measurement of outcomes important to patients, but also promotes discussing these outcomes during clinical encounters, is long overdue.

METHODS

An international expert group (EG) of patient advocates, researchers, medical specialists, nurse specialists, and pharmaceutical industry representatives (n = 17) reviewed a list of relevant outcomes retrieved from the literature. A broader group (n = 141: patients/patient advocates (n = 45), health care professionals/researchers (n = 64), pharmaceutical industry representatives (n = 28), and health authority representatives (n = 4)) participated in a modified Delphi procedure, scoring the relevance of outcomes in two survey rounds. The EG finalized the COS in a consensus meeting.

RESULTS

The final MBC COS includes 101 variables about: (1) health-related quality of life (HRQoL, n = 26) and adverse events (n = 24); (2) baseline patient characteristics (n = 9); and (3) clinical variables (n = 42). Many outcome that cover aspects of HRQoL relevant to MBC patients are included, e.g. daily functioning (including ability to work), psychosocial/emotional functioning, sexual functioning, and relationship with the medical team.

CONCLUSION

The COS developed in this study contains important administrative data, clinical records, and clinician-reported measures that captures the impact of cancer. The COS is important for standardization of clinical research and implementation in daily practice and has received accreditation by the International Consortium for Health Outcomes Measurement (ICHOM).

Macrophage migration inhibitory factor promotes the migration of dendritic cells through CD74 and the activation of the Src/PI3K/myosin II pathway

Constitutively expressed by innate immune cells, the cytokine macrophage migration inhibitory factor (MIF) initiates host immune responses and drives pathogenic responses in infectious, inflammatory, and autoimmune diseases. Dendritic cells (DCs) express high levels of MIF, but the role of MIF in DC function remains poorly characterized. As migration is critical for DC immune surveillance, we investigated whether MIF promoted the migration of DCs. In classical transwell experiments, MIF^-/- bone marrow-derived DCs (BMDCs) or MIF^+/+ BMDCs treated with ISO-1, an inhibitor of MIF, showed markedly reduced spontaneous migration and chemotaxis. CD74^-/- BMDCs that are deficient in the ligand-binding component of the cognate MIF receptor exhibited a migration defect similar to that of MIF^-/- BMDCs. Adoptive transfer experiments of LPS-matured MIF^+/+ and MIF^-/- and of CD74^+/+ and CD74^-/- BMDCs injected into the hind footpads of homologous or heterologous mice showed that the autocrine and paracrine MIF activity acting via CD74 contributed to the recruitment of DCs to the draining lymph nodes. Mechanistically, MIF activated the Src/PI3K signaling pathway and myosin II complexes, which were required for the migration of BMDCs. Altogether, these data show that the cytokine MIF exerts chemokine-like activity for DC motility and trafficking.

Recombinant HIV-1 vaccine candidates based on replication-defective flavivirus vector

Multiple approaches utilizing viral and DNA vectors have shown promise in the development of an effective vaccine against HIV. In this study, an alternative replication-defective flavivirus vector, RepliVax (RV), was evaluated for the delivery of HIV-1 immunogens. Recombinant RV-HIV viruses were engineered to stably express clade C virus Gag and Env (gp120TM) proteins and propagated in Vero helper cells. RV-based vectors enabled efficient expression and correct maturation of Gag and gp120TM proteins, were apathogenic in a sensitive suckling mouse neurovirulence test, and were similar in immunogenicity to recombinant poxvirus NYVAC-HIV vectors in homologous or heterologous prime-boost combinations in mice. In a pilot NHP study, immunogenicity of RV-HIV viruses used as a prime or boost for DNA or NYVAC candidates was compared to a DNA prime/NYVAC boost benchmark scheme when administered together with adjuvanted gp120 protein. Similar neutralizing antibody titers, binding IgG titers measured against a broad panel of Env and Gag antigens, and ADCC responses were observed in the groups throughout the course of the study, and T cell responses were elicited. The entire data demonstrate that RV vectors have the potential as novel HIV-1 vaccine components for use in combination with other promising candidates to develop new effective vaccination strategies.

Global characteristics of the rabies biologics market in 2017

In 2017, the World Health Organization, the World Organisation for Animal Health, the Food and Agriculture Organization of the United Nations and the Global Alliance for Rabies control developed a strategic plan to end human rabies deaths by 2030.

A survey for manufacturing capacity and product characteristics of rabies biologics was conducted to inform this process. Twenty-three of 42 manufacturers, responded, giving a market capacity for 2017 of 90 million vials for human vaccines, 2.5 million vials for rabies immunoglobulins, 2 million vials for monoclonal antibodies and 181 million vials for dog vaccines.

Production capacity could be increased by many manufacturers but was limited by country demand, lack of long-term planning and restricted market expansion. Should countries implement national rabies elimination programmes where biologic needs are forecasted and production lead times respected, manufacturers can meet future supply needs towards global elimination of human dog-mediated rabies deaths.

Rate of positive diagnosis of skin cancer and its stage in two-week wait referrals in England according to age

BACKGROUND

The incidence of skin cancer is increasing. The two-week wait conversion rate (TWWCR) is the percentage of urgent suspected skin cancer referrals that are confirmed as cancer.

AIMS

To examine the relationships between different epidemiological factors and TWWCR for malignant melanoma (MM) and cutaneous squamous cell carcinoma (SCC).

METHODS

We extracted data from the National Cancer Data Repository (NCDR) and National Cancer Waiting Times Monitoring Dataset between 2009 and 2010 for MM and SCC in England. We conducted partial correlation and stepwise multiple regression analysis on TWWCR, age, incidence, detection rate, tumour thickness (MM only), percentage MM/SCC and social deprivation. We also looked at the two-week wait referral rate (TWWRR) and incidence rate with respect to age.

RESULTS

TWWCR was significantly correlated with age when partial correlation was used to control for the factors described above for MM (P < 0.05) and SCC (P < 0.001). Stepwise regression of these factors returned only age as significant in the final model for MM (P < 0.001) and SCC (P < 0.01). Incidence of MM and SCC increased with age. TWWRR also increase with age, but with higher rate in younger people relative to their incidence.

CONCLUSIONS

Age is a predictor of TWWCR independent of the other factors measured, including thickness and incidence. This may be explained by the higher number of referrals for younger patients despite the lower incidence of skin cancer in this group. This may reflect a more appropriate rate of referral in order to achieve earlier diagnosis and better outcomes.

MyD88 and TLR9 dependent immune responses mediate resistance to Leishmania guyanensis infections, irrespective of Leishmania RNA virus burden

Infections with Leishmania parasites of the Leishmania Viannia subgenus give rise to both localized cutaneous (CL), and metastatic leishmaniasis. Metastasizing disease forms including disseminated (DCL) and mutocutaneous (MCL) leishmaniasis result from parasitic dissemination and lesion formation at sites distal to infection and have increased inflammatory responses. The presence of Leishmania RNA virus (LRV) in L. guyanensis parasites contributes to the exacerbation of disease and impacts inflammatory responses via activation of TLR3 by the viral dsRNA. In this study we investigated other innate immune response adaptor protein modulators and demonstrated that both MyD88 and TLR9 played a crucial role in the development of Th1-dependent healing responses against L. guyanensis parasites regardless of their LRV status. The absence of MyD88- or TLR9-dependent signaling pathways resulted in increased Th2 associated cytokines (IL-4 and IL-13), which was correlated with low transcript levels of IL-12p40. The reliance of IL-12 was further confirmed in IL12AB^−/− mice, which were completely susceptible to infection. Protection to L. guyanensis infection driven by MyD88- and TLR9-dependent immune responses arises independently to those induced due to high LRV burden within the parasites.

Xanthine oxidase inhibition by febuxostat attenuates experimental atherosclerosis in mice

Atherosclerosis is a chronic inflammatory disease due to lipid deposition in the arterial wall. Multiple mechanisms participate in the inflammatory process, including oxidative stress. Xanthine oxidase (XO) is a major source of reactive oxygen species (ROS) and has been linked to the pathogenesis of atherosclerosis, but the underlying mechanisms remain unclear. Here, we show enhanced XO expression in macrophages in the atherosclerotic plaque and in aortic endothelial cells in ApoE(-/-) mice, and that febuxostat, a highly potent XO inhibitor, suppressed plaque formation, reduced arterial ROS levels and improved endothelial dysfunction in ApoE(-/-) mice without affecting plasma cholesterol levels. In vitro, febuxostat inhibited cholesterol crystal-induced ROS formation and inflammatory cytokine release in murine macrophages. These results demonstrate that in the atherosclerotic plaque, XO-mediated ROS formation is pro-inflammatory and XO-inhibition by febuxostat is a potential therapy for atherosclerosis.

Pathogenic role of basic calcium phosphate crystals in destructive arthropathies

BACKGROUND

basic calcium phosphate (BCP) crystals are commonly found in osteoarthritis (OA) and are associated with cartilage destruction. BCP crystals induce in vitro catabolic responses with the production of metalloproteases and inflammatory cytokines such as interleukin-1 (IL-1). In vivo, IL-1 production induced by BCP crystals is both dependant and independent of NLRP3 inflammasome. We aimed to clarify 1/ the role of BCP crystals in cartilage destruction and 2/ the role of IL-1 and NLRP3 inflammasome in cartilage degradation related to BCP crystals.

METHODOLOGY PRINCIPAL FINDINGS

synovial membranes isolated from OA knees were analysed by alizarin Red and FTIR. Pyrogen free BCP crystals were injected into right knees of WT, NLRP3 -/-, ASC -/-, IL-1α -/- and IL-1β-/- mice and PBS was injected into left knees. To assess the role of IL-1, WT mice were treated by intra-peritoneal injections of anakinra, the IL-1Ra recombinant protein, or PBS. Articular destruction was studied at d4, d17 and d30 assessing synovial inflammation, proteoglycan loss and chondrocyte apoptosis. BCP crystals were frequently found in OA synovial membranes including low grade OA. BCP crystals injected into murine knee joints provoked synovial inflammation characterized by synovial macrophage infiltration that persisted at day 30, cartilage degradation as evidenced by loss of proteoglycan staining by Safranin-O and concomitant expression of VDIPEN epitopes, and increased chondrocyte apoptosis. BCP crystal-induced synovitis was totally independent of IL-1α and IL-1β signalling and no alterations of inflammation were observed in mice deficient for components of the NLRP3-inflammasome, IL-1α or IL-1β. Similarly, treatment with anakinra did not prevent BCP crystal effects. In vitro, BCP crystals elicited enhanced transcription of matrix degrading and pro-inflammatory genes in macrophages.

CONCLUSIONS SIGNIFICANCE

intra-articular BCP crystals can elicit synovial inflammation and cartilage degradation suggesting that BCP crystals have a direct pathogenic role in OA. The effects are independent of IL-1 and NLRP3 inflammasome.

Routes to diagnosis for cancer - determining the patient journey using multiple routine data sets

BACKGROUND

Cancer survival in England is lower than the European average, which has been at least partly attributed to later stage at diagnosis in English patients. There are substantial regional and demographic variations in cancer survival across England. The majority of patients are diagnosed following symptomatic or incidental presentation. This study defines a methodology by which the route the patient follows to the point of diagnosis can be categorised to examine demographic, organisational, service and personal reasons for delayed diagnosis.

METHODS

Administrative Hospital Episode Statistics data are linked with Cancer Waiting Times data, data from the cancer screening programmes and cancer registration data. Using these data sets, every case of cancer registered in England, which was diagnosed in 2006-2008, is categorised into one of eight 'Routes to Diagnosis'.

RESULTS

Different cancer types show substantial differences between the proportion of cases that present by each route, in reasonable agreement with previous clinical studies. Patients presenting via Emergency routes have substantially lower 1-year relative survival.

CONCLUSION

Linked cancer registration and administrative data can be used to robustly categorise the route to a cancer diagnosis for all patients. These categories can be used to enhance understanding of and explore possible reasons for delayed diagnosis.

High incidence of skin cancer in the Channel Islands

BACKGROUND

Previous studies looking at rates of malignant melanoma (MM) and nonmelanoma skin cancer (NMSC) in the UK have documented one of the highest rates in the southwest of England; however, the incidence of these tumours in Guernsey and Jersey, two of the Channel Islands, has not previously been reported.

AIMS

To determine the incidence of cutaneous MM and NMSC in the Channel Islands.

METHODS

Data for the period 2005-2009 were obtained from clinical and histopathological records for all MMs excised in the Channel Islands, and from the South-west Cancer Registry for MMs excised in the southwest of England and for NMSCs in both areas. The age-standardized incidence rate (ASRs) per 100,000 of the population in the Channel Islands were compared with those with the southwest of England, the UK and the rest of Europe where available. The MM characteristics of the Channel Islands were then compared with the southwest of England using standardized incidence ratios (SIRs).

RESULTS

The ASR/100,000 for cutaneous MM for 2005-2009 was 30 for the Channel Islands (31.3 for Jersey, 28.2 for Guernsey), 20.3 for the southwest of England, and 15.6 for the UK. Comparison with the rest of Europe indicated that the incidence of MM in the Channel Islands is one of the highest in Europe. The highest incidence of MM was in the over 65 years age group on both Guernsey and Jersey, and when divided into 5-year age bands, the 70-74 years age group had the highest rate. This suggests that this particular age group may have previously received greater exposure to some environmental factor that promotes MM development. The ASR/100,000 for NMSC was also higher for the Channel Islands (263.3) than for the southwest of England (174.6) for 2005-2009, and for the UK in 2009 (104.9).

CONCLUSIONS

This study indicates that the Channel Islands have a high incidence of skin cancer (both MM and NMSC). In addition, the data show that the ASRs in older people in this population group differ from those in mainland UK, showing higher rates in the over 65 years age group.

Periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis syndrome is linked to dysregulated monocyte IL-1β production

BACKGROUND

The exact pathogenesis of the pediatric disorder periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis (PFAPA) syndrome is unknown.

OBJECTIVES

We hypothesized that PFAPA might be due to dysregulated monocyte IL-1β production linked to genetic variants in proinflammatory genes.

METHODS

Fifteen patients with PFAPA syndrome were studied during and outside a febrile episode. Hematologic profile, inflammatory markers, and cytokine levels were measured in the blood. The capacity of LPS-stimulated PBMCs and monocytes to secrete IL-1β was assessed by using ELISA, and active IL-1β secretion was visualized by means of Western blotting. Real-time quantitative PCR was performed to assess cytokine gene expression. DNA was screened for variants of the MEFV, TNFRSF1A, MVK, and NLRP3 genes in a total of 57 patients with PFAPA syndrome.

RESULTS

During a febrile attack, patients with PFAPA syndrome revealed significantly increased neutrophil counts, erythrocyte sedimentation rates, and C-reactive protein, serum amyloid A, myeloid-related protein 8/14, and S100A12 levels compared with those seen outside attacks. Stimulated PBMCs secreted significantly more IL-1β during an attack (during a febrile episode, 575 ± 88 pg/mL; outside a febrile episode, 235 ± 56 pg/mL; P < .001), and this was in the mature active p17 form. IL-1β secretion was inhibited by ZYVAD, a caspase inhibitor. Similar results were found for stimulated monocytes (during a febrile episode, 743 ± 183 pg/mL; outside a febrile episode, 227 ± 92 pg/mL; P < .05). Genotyping identified variants in 15 of 57 patients, with 12 NLRP3 variants, 1 TNFRSF1A variant, 4 MEFV variants, and 1 MVK variant.

CONCLUSION

Our data strongly suggest that IL-1β monocyte production is dysregulated in patients with PFAPA syndrome. Approximately 20% of them were found to have NLRP3 variants, suggesting that inflammasome-related genes might be involved in this autoinflammatory syndrome.

Increased incidence of bronchopulmonary fistulas complicating pediatric pneumonia

BACKGROUND

The frequency of complicated pneumococcal disease, including necrotizing pneumonia, has increased over the last decade. During 2008-2009, we noted an increase in the number of children whose empyema was complicated by the development of a bronchopleural fistula and air leak. We studied these children to see if there was an associated cause.

METHODS

This was a retrospective case note and database review of children admitted to our tertiary unit with a parapneumonic effusion or empyema from 2002 to 2007, compared with 2008 to 2009. For the latter period, we also compared the outcomes of those with a bronchopleural fistula to those without.

RESULTS

During the 8-year period, 310 children were admitted. In the first 6 years, the frequency of air leaks was 1% (2/258) rising to 33% (16/49) in the last 2 years (P<0.0001). Three children were excluded as their fistulas were possibly iatrogenic. This was associated with a significant increase in median hospital stay (7 vs. 10 days, P<0.0001) and surgical intervention rate (2% vs. 14%, P=0.001). In the latter 2 years, S. pneumoniae serotype 3 was identified in 10/16 (91%) of those with a bronchopleural fistula compared to 1/33 (3%) of those without.

CONCLUSIONS

The frequency of bronchopleural fistulas increased markedly in the 2 years 2008-2009. Although these cases were associated with pneumococcal serotype 3 infection, which was not covered by the heptavalent pneumococcal vaccine Prevenar® in use at that time, we do not know whether the increased incidence of fistulas was due to a change in serotype 3 prevalence.

Type I interferon drives dendritic cell apoptosis via multiple BH3-only proteins following activation by PolyIC in vivo

Background

DC are activated by pathogen-associated molecular patterns (PAMPs), and this is pivotal for the induction of adaptive immune responses. Thereafter, the clearance of activated DC is crucial to prevent immune pathology. While PAMPs are of major interest for vaccine science due to their adjuvant potential, it is unclear whether and how PAMPs may affect DC viability. We aimed to elucidate the possible apoptotic mechanisms that control activated DC lifespan in response to PAMPs, particularly in vivo.

Methodology/Principal Findings

We report that polyinosinic:polycytidylic acid (PolyIC, synthetic analogue of dsRNA) induces dramatic apoptosis of mouse splenic conventional DC (cDC) in vivo, predominantly affecting the CD8α subset, as shown by flow cytometry-based analysis of splenic DC subsets. Importantly, while Bim deficiency conferred only minor protection, cDC depletion was prevented in mice lacking Bim plus one of three other BH3-only proteins, either Puma, Noxa or Bid. Furthermore, we show that Type I Interferon (IFN) is necessary and sufficient for DC death both in vitro and in vivo, and that TLR3 and MAVS co-operate in IFNß production in vivo to induce DC death in response to PolyIC.

Conclusions/Significance

These results demonstrate for the first time in vivo that apoptosis restricts DC lifespan following activation by PolyIC, particularly affecting the CD8α cDC subset. Such DC apoptosis is mediated by the overlapping action of pro-apoptotic BH3-only proteins, including but not solely involving Bim, and is driven by Type I IFN. While Type I IFNs are important anti-viral factors, CD8α cDC are major cross-presenting cells and critical inducers of CTL. We discuss such paradoxical finding on DC death with PolyIC/Type I IFN. These results could contribute to understand immunosuppression associated with chronic infection, and to the optimization of DC-based therapies and the clinical use of PAMPs and Type I IFNs.

Leishmania RNA virus controls the severity of mucocutaneous leishmaniasis

Mucocutaneous leishmaniasis is caused by infections with intracellular parasites of the Leishmania Viannia subgenus, including Leishmania guyanensis. The pathology develops after parasite dissemination to nasopharyngeal tissues, where destructive metastatic lesions form with chronic inflammation. Currently, the mechanisms involved in lesion development are poorly understood. Here we show that metastasizing parasites have a high Leishmania RNA virus-1 (LRV1) burden that is recognized by the host Toll-like receptor 3 (TLR3) to induce proinflammatory cytokines and chemokines. Paradoxically, these TLR3-mediated immune responses rendered mice more susceptible to infection, and the animals developed an increased footpad swelling and parasitemia. Thus, LRV1 in the metastasizing parasites subverted the host immune response to Leishmania and promoted parasite persistence.

The MyD88 protein 88 pathway is differently involved in immune responses induced by distinct substrains of Leishmania major

Host resistance to Leishmania major is highly dependent on the development of a Th1 immune response. The TLR adaptator myeloid differentiation protein 88 (MyD88) has been implicated in the Th1 immune response associated with the resistant phenotype observed in C57BL/6 mice after infection with L. major. To investigate whether the MyD88 pathway is differentially used by distinct substrains of parasites, MyD88(-/-) C57BL/6 mice were infected with two substrains of L. major, namely L. major LV39 and L. major IR75. MyD88(-/-) mice were susceptible to both substrains of L. major, although with different kinetics of infection. The mechanisms involved during the immune response associated with susceptibility of MyD88(-/-) mice to L. major is however, parasite substrain-dependent. Susceptibility of MyD88(-/-) mice infected with L. major IR75 is a consequence of Th2 immune-deviation, whereas susceptibility of MyD88(-/-) mice to infection with L. major LV39 resulted from an impaired Th1 response. Depletion of regulatory T cells (Treg) partially restored IFN-gamma secretion and the Th1 immune response in MyD88(-/-) mice infected with L. major LV39, demonstrating a role of Treg activity in the development of an impaired Th1 response in these mice.

Measurement and repeatability of interrupter resistance in unsedated newborn infants

Interrupter resistance (R(int)) is a useful measure of airway caliber in young children, but has not been well characterized in infants-in whom there are concerns about the accurate measurement of driving pressure. This study aimed to assess the feasibility and repeatability of measuring R(int) in unsedated newborn infants, and to explore alternative algorithms for calculating driving pressure. R(int) measurement was attempted in 28 healthy term newborn infants during natural sleep using the MicroRint device. Paired R(int) measurements were achieved in 24 infants, but after screening of waveforms only 15 infants had at least 5 technically acceptable waveforms on both measurements. R(int) values obtained were comparable with reported values for airflow resistance in newborns using other methods. However, the repeatability coefficient (CR) was much higher than reported values in preschool children using standard back-extrapolation algorithms, with CR 2.47 KPa L(-1) sec (unscreened) and 2.93 KPa L(-1) sec (screened). Other algorithms gave only marginally better repeatability, with all CR values over 50% of the mean R(int) value. Using current commercially available equipment, R(int) is too poorly repeatable to be a reliable measurement of airflow resistance in newborn infants. Lower deadspace equipment is needed, but anatomical and physiological factors in the infant are also important.

Resistance to oxidative stress is associated with metastasis in mucocutaneous leishmaniasis

Mucocutaneous leishmaniasis (MCL) in South and Central America is characterized by the dissemination (metastasis) of Leishmania Viannia subgenus parasites from a cutaneous lesion to nasopharyngeal tissues. Little is known about the pathogenesis of MCL, especially with regard to the virulence of the parasites and the process of metastatic dissemination. We previously examined the functional relationship between cytoplasmic peroxiredoxin and metastatic phenotype using highly, infrequently, and nonmetastatic clones isolated from an L. (V.) guyanensis strain previously shown to be highly metastatic in golden hamsters. Distinct forms of cytoplasmic peroxiredoxin were identified and found to be associated with the metastatic phenotype. We report here that peroxidase activity in the presence of hydrogen peroxide and infectivity differs between metastatic and nonmetastatic L. (V.) guyanensis clones. After hydrogen peroxide treatment or heat shock, peroxiredoxin was detected preferentially as dimers in metastatic L. (V.) guyanensis clones and in L. (V.) panamensis strains from patients with MCL, compared with nonmetastatic parasites. These data provide evidence that resistance to the first microbicidal response of the host cell by Leishmania promastigotes is linked to peroxiredoxin conformation and may be relevant to intracellular survival and persistence, which are prerequisites for the development of metastatic disease.

Analysis of CD4+ T-Cell responses to a novel alpha-fetoprotein-derived epitope in hepatocellular carcinoma patients

PURPOSE

Alpha-fetoprotein (AFP) is a tumor-associated antigen in hepatocellular carcinoma and is a target for the development of cancer vaccine. Four immunodominant AFP-derived HLA-A*0201-restricted peptides have been identified and the administration of these peptides with an adjuvant has stimulated AFP-specific CTL responses in hepatocellular carcinoma patients. However, no AFP-derived CD4 T-cell epitope has yet been reported and the status of AFP-specific CD4(+) T-cell responses in hepatocellular carcinoma patients is not fully understood. The aim of this study was to analyze naturally occurring CD4(+) T-cell responses to AFP.

EXPERIMENTAL DESIGN

We analyzed the ability of CD4(+) T cells to recognize an HLA-DR-restricted AFP-derived epitope in 41 hepatocellular carcinoma patients and 24 non-hepatocellular carcinoma control patients using intracellular cytokine assays for IFN-gamma.

RESULTS

Here, for the first time, we report the identification of an AFP-derived CD4(+) T-cell epitope that is recognized by circulating lymphocytes from hepatocellular carcinoma patients in association with HLA-DR. The absence of detectable responses in healthy donors and patients with chronic liver disease suggests that AFP-specific CD4(+) T cells in the responder patients had been previously expanded in vivo in response to the tumor. The anti-AFP CD4(+) T-cell response was only detected in hepatocellular carcinoma patients with normal or mildly elevated serum AFP levels who were in the early stage of disease.

CONCLUSION

Our data will be instrumental in the development of cancer vaccine using AFP-derived immunogens.

Colonic pseudo-obstruction in burns patients

Acute pseudo-obstruction is a rare complication in burns patients. An awareness of the factors implicated in its pathogenesis such as prolonged bed rest, narcotic medications, hypokalaemia, sepsis and surgery (all commonly associated with burns patients) is essential if this condition is to be avoided. Early diagnosis, prokinetic and cathartic agents, and aggressive endoscopic intervention are essential to halt the progression of caecal dilatation. Excisional surgery and stoma formation are necessary for salvage of complicated colonic pseudo-obstruction.