Early expression of interferon-gamma inducible protein 10 and monokine induced by interferon-gamma in cardiac allografts is mediated by CD8+ T cells

BACKGROUND: Our goal was to test the intragraft mRNA expression and production of two chemokines that are potent chemoattractants for antigen-primed T cells, interferon-gamma inducible protein 10 (IP-10) and monokine-induced by IFN-gamma, (Mig), in allogeneic heart grafts. METHODS: Syngeneic or allogeneic A/J (H-2a) hearts were heterotopically transplanted to wild-type, CD4-/-, CD8alpha-/-, or IFN-gamma-/- C57BL/6 (H-2b) recipients. To test expression of IP-10 and Mig, grafts were removed 1-8 days posttransplant for RNA isolation and Northern blot analysis. To test the potential recipient leukocyte populations mediating intraallograft expression of IP-10 and Mig, recipients were treated with anti-NK 1.1, anti-CD4, and/or anti-CD8 monoclonal antibodies before transplantation. RESULTS: Allogeneic heart grafts transplanted to wild-type, but not IFN-gamma-/-, recipients expressed IP-10 and Mig at day +2 posttransplant that increased thereafter until rejection was completed. Expression of IP-10 and Mig in isografts was low or undetectable. Cardiac allografts from CD8+ T cell depleted, but not NK cell or CD4+ T cell depleted, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. Similarly, cardiac allografts from CD8-/-, but not CD4-/-, recipients had low to undetectable expression of IP-10 and Mig on day +2 posttransplant. CONCLUSIONS: Early intraallograft expression of Mig and IP-10 during primary rejection of cardiac allografts is dependent on the activities of recipient CD8+ T cells.     

Early increased chemokine expression and production in murine allogeneic skin grafts is mediated by natural killer cells

BACKGROUND: Increased expression of chemokine mRNA is observed in allogeneic but not syngeneic skin grafts 3-4 days after transplantation. The recipient cells mediating this early inflammatory response in allografts remain unidentified. METHODS: Isogeneic and allogeneic skin grafts were transplanted to euthymic and athymic nude mice. mRNA expression and protein production of macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and the murine homolog of Gro(alpha), i.e. KC, from graft homogenates retrieved 3-4 days posttransplantation was tested by Northern blot hybridization and ELISA. To deplete NK cells, recipients were treated with antiasialo GM1 (ASGM1) antisera or with anti-NK1.1 mAb before transplantation. RESULTS: Expression of KC, MIP-1alpha, and MIP-1beta mRNA was equivalent in C57BL/6 allogeneic skin grafts and BALB/c isografts at day 2 posttransplant. At day 3 posttransplant, chemokine mRNA levels decreased in isografts but were maintained at high levels in the allografts. Increased early chemokine mRNA was also observed in C57BL/6, but not BALB/c++ grafts on BALB/c athymi(nu/nu) recipients. Treatment of allograft recipients with ASGM1 or with anti-NK1.1 antibody eliminated NK cells from the spleen and allograft infiltrating cell populations and decreased early chemokine mRNA levels in allografts 60-70%. Analyses of allograft homogenates indicated increased levels of KC, MIP-1alpha, and MIP-1beta protein at day 4 posttransplant that were decreased in recipients depleted of NK cells. Early chemokine mRNA levels were equivalent in isogeneic and semiallogeneic F1 grafts. CONCLUSIONS: Early chemokine mRNA expression and protein production in allogeneic skin grafts is amplified by recipient natural killer (NK) cells. These results indicate a novel function for infiltrating NK cells in mediating early increased intra-allograft chemokine production and inflammation during the initiation of acute rejection.     

Can Sensitized Lymphocytes Retain Reactivity to Inner Ear Antigens After Retrieval From Frozen Storage?

Immune inner ear disease results in rapidly progressive, bilateral sensorineural hearing loss and is one of the few forms of sensorineural hearing loss that can be treated medically. The purpose of this study is to identify and preserve several populations of sensitized lymphocytes from patients with immune inner ear disease as a first step toward cloning autoreactive T cells, in order to study the pathogenesis of disease. Lymphocytes from four patients with high reactivity (stimulation index of 2.5 or greater) were placed in frozen storage. At 8 to 14 months they were thawed and restimulated. All four samples were viable. Two reacted again to inner ear homogenate, but with different intensities. Some lymphocytes sensitized to inner ear antigens can retain reactivity after frozen storage. This methodology may be useful to clone highly reactive T cells.     

p53 Protein Expression in a Population-Based Series of Primary Vulval Squamous Cell Carcinoma and Immediate Adjacent Field Change

Objectives.Our aim was to study correlations between survival, disease recurrence, and p53 protein expression in a well defined population-based series of vulval squamous cell carcinoma and immediate adjacent epithelial skin changes.Methods.One hundred fifteen vulval squamous cell carcinoma were studied. Epithelial skin changes immediately adjacent to tumor were classified into nonneoplastic epithelial disorders (NNED) or vulval intraepithelial neoplasia (VIN). Archival specimens containing primary tumor and immediate adjacent skin were immunostained with a mouse monoclonal antibody to p53 protein.Results.p53 overexpression, defined as greater than 10% nuclear epithelial staining, was observed in 68% of tumors. Tumor immunostaining did not correlate with actuarial survival or disease-free interval. p53 overexpression was associated with a nonsignificant trend toward shorter disease-free interval in those tumors with nodal metastatic disease at diagnosis (P= 0.07). The only clinicopathological variable found to correlate with p53 expression was tumor grade (P= 0.002). Immediate adjacent abnormal skin changes were associated with p53 overexpression in 32% of cases. Adjacent normal skin did not immunostain for p53. p53 overexpression was most likely to occur in adjacent epithelial changes incorporating both NNED and high grade VIN (P= 0.005). Patterns of epithelial p53 overexpression in adjacent abnormal skin were either basal or full thickness. Full thickness epithelial p53 overexpression was most likely to occur in those disorders containing VIN (P< 0.0001). Positive immunostaining of adjacent skin abnormalities did not predict local tumor recurrence.Conclusions.This study demonstrates that although vulval squamous tumor p53 expression is not of prognostic significance, distinct immunostaining patterns can be observed in immediate adjacent skin. Vulval epithelial skin disorders displaying histological features of both NNED and VIN III may contain a profile of underlying molecular change which is of significance in subsequent tumor development.     

Pneumococcal meningitis: development of a new animal model.

HYPOTHESIS: The rat is a suitable animal to establish a model for the study of pneumococcal meningitis postcochlear implantation. BACKGROUND: There has been an increase in the number of cases of cochlear implant-related meningitis. The most common organism identified was Streptococcus pneumoniae. Whether cochlear implantation increases the risk of pneumococcal meningitis in healthy subjects without other risk factors remains to be determined. Previous animal studies do not focus on the pathogenesis and risk of pneumococcal meningitis postimplantation and are based on relatively small animal numbers, making it difficult to assess the cause-and-effect relationship. There is, therefore, a need to develop a new animal model allowing direct examination of the pathogenesis of meningitis in the presence of a cochlear implant. METHODS: Eighteen nonimplanted rats were infected with 1 x 10 and 1 x 10 colony-forming units (CFU) of a clinical isolate of S. pneumoniae via three different inoculation routes (middle ear, inner ear, and i.p.) to examine for evidence of meningitis during 24 hours. Six implanted rats were infected with the highest amount of bacteria possible for each route of inoculation (4 x 10 CFU i.p., 3 x 10 CFU middle ear, and 1 x 10 CFU inner ear) to examine for evidence of meningitis with the presence of an implant. The histological pattern of cochlear infections for each of the three different inoculating routes were examined. RESULTS: Pneumococcal meningitis was evident in all 6 implanted animals for each of the three different routes of inoculation. Once in the inner ear, bacteria were found to enter the central nervous system via either the cochlear aqueduct or canaliculi perforantes of the osseous spiral lamina, reaching the perineural and perivascular space then the internal acoustic meatus. The rate, extent, and pattern of infection within the cochleae depended on the route of inoculation. Finally, there was no evidence of pneumococcal meningitis observed in 18 nonimplanted rats inoculated at a lower concentration of S. pneumoniae when observed for 24 hours postinoculation. CONCLUSION: Meningitis in implanted rats after inoculation with a clinical isolate of S. pneumoniae is possible via all three potential routes of infection via the upper respiratory tract. The lack of meningitis observed in the 18 nonimplanted rats suggests that longer postinoculation monitoring periods are required to ensure whether or not meningitis will develop. Based on this work, we have developed a new animal model that will allow quantitative risk assessment of meningitis postcochlear implantation, and the assessment of the efficacy of potential interventional strategies in future studies.     

Bench to bedside review: Extracorporeal carbon dioxide removal,past present and future

Acute respiratory distress syndrome (ARDS) has a substantial mortality rate and annually affects more than 140,000 people in the USA alone. Standard management includes lung protective ventilation but this impairs carbon dioxide clearance and may lead to right heart dysfunction or increased intracranial pressure. Extracorporeal carbon dioxide removal has the potential to optimize lung protective ventilation by uncoupling oxygenation and carbon dioxide clearance. The aim of this article is to review the carbon dioxide removal strategies that are likely to be widely available in the near future. Relevant published literature was identified using PubMed and Medline searches. Queries were performed by using the search terms ECCOR, AVCO2R, VVCO2R, respiratory dialysis, and by combining carbon dioxide removal and ARDS. The only search limitation imposed was English language. Additional articles were identified from reference lists in the studies that were reviewed. Several novel strategies to achieve carbon dioxide removal were identified, some of which are already commercially available whereas others are in advanced stages of development.     

Targeting the “Cytokine Storm” for Therapeutic Benefit

Inflammation is the body''s first line of defense against infection or injury, responding to challenges by activating innate and adaptive responses. Microbes have evolved a diverse range of strategies to avoid triggering inflammatory responses. However, some pathogens, such as the influenza virus and the Gram-negative bacterium Francisella tularensis, do trigger life-threatening “cytokine storms” in the host which can result in significant pathology and ultimately death. For these diseases, it has been proposed that downregulating inflammatory immune responses may improve outcome. We review some of the current candidates for treatment of cytokine storms which may prove useful in the clinic in the future and compare them to more traditional therapeutic candidates that target the pathogen rather than the host response.