Immune mechanisms in the pathogenesis of bronchiolitis obliterans syndrome after lung transplantation

Lung transplantation is recognized as the only viable treatment option in a variety of end-stage pulmonary diseases. However, the long-term survival after lung transplantation is limited by the development of obliterative bronchiolitis, and its clinical correlate bronchiolitis obliterans syndrome (BOS), which is considered to represent chronic lung allograft rejection. Histopathologically, BOS is an inflammatory process that leads to fibrous scarring of the terminal and respiratory bronchioles and subsequent total occlusion of the airways. The specific etiology and pathogenesis of BOS are not well understood. The current premise is that BOS represents a common lesion in which different inflammatory insults such as ischemia-reperfusion, rejection, and infection can lead to a similar histological and clinical outcome. However, the low incidence of BOS in non-transplanted individuals and the observation that early development of BOS is predicted by the frequency and severity of acute rejection episodes indicate that alloimmune-dependent mechanisms play a crucial role in the pathogenesis of BOS. The evidence presented in this review indicates that BOS is the result of humoral and cellular immune responses developed against major histocompatibility complex molecules expressed by airway epithelial cells of the lung allograft. This process is aggravated by alloimmune-independent mechanisms such as ischemia-reperfusion and infection. Currently, treatment of BOS is frequently unsuccessful. Therefore, a better understanding of the immunopathogenesis of BOS is of paramount importance toward improving long-term patient and graft survival after lung transplantation.     

Aspirin Curtails the Acetaminophen-Induced Rise in Brain Norepinephrine Levels

We previously showed that acetaminophen administration to rats increases forebrain serotonin levels as a result of the inhibition of liver tryptophan-2,3-dioxygenase (TDO). In this study we determined whether aspirin alone and in combination with acetaminophen could further influence brain serotonin as well as norepinephrine levels and if so whether the status of the liver TDO activity would be altered. The results show that acetaminophen alone increases brain serotonin as well as norepinephrine levels with a concomitant inhibition of liver TDO activity. In contrast, aspirin did not alter the levels of these monoamines but increased serotonin turnover in the brain while acetaminophen decreased the turnover. When combined with acetaminophen, aspirin overrides the reduced serotonin turnover induced by acetaminophen. This report demonstrates the potential of these agents to alter neurotransmitter levels in the brain.     

Anti-CD40 ligand monoclonal antibody induces a permissive state, but not tolerance, for murine peripheral nerve allografts

Anti-CD40 ligand monoclonal antibody prevents the interaction between CD40 and its T-cell-based ligand, thereby resulting in selective inhibition of T cell costimulation without pan-T-cell suppression. This antibody has found application in several animal models of solid organ transplantation. This study investigated use of anti-CD40 ligand antibody to promote acceptance of nerve allografts. In Experiment 1, 40 BALB/cj mice with tibial nerve transplants were administered anti-CD40 ligand antibody, a control antibody, or no treatment. In Experiment 2, 40 BALB/cj mice underwent the same regimen as in Experiment 1, but were later challenged with a second nerve allograft 3 weeks after discontinuation of treatment. Animals treated with anti-CD40 ligand antibody in Experiment 1 exhibited improved functional recovery and greater mean fiber count, fiber density, and percent nerve fiber than animals treated with control antibody or no antibody (P < 0.05). These permissive effects on nerve regeneration were associated with immune unresponsiveness on Elispot assay. The benefit of anti-CD40 ligand therapy did not persist after withdrawal of treatment (Experiment 2). Active blockade of the CD40 costimulatory pathway with murine anti-CD40 ligand antibody therefore induces a permissive state conducive to nerve regeneration across allografts but does not establish long-term tolerance.     

Generation of CD8+ cytotoxic T lymphocytes against breast cancer cells by stimulation with mammaglobin-A-pulsed dendritic cells

Mammaglobin-A is exclusively expressed by breast cancer cells. Thus, mammaglobin-A-specific T cell immune responses may be useful for the design of new breast cancer-specific immunotherapies. We show herein that CD8+ T cells generated against recombinant mammaglobin-A-pulsed dendritic cells display a marked cytotoxic activity against mammaglobin-A-positive breast cancer cell lines. This study indicates the immunotherapeutic potential of this novel antigen for the treatment of breast cancer.     

The association of HLA class II with pars planitis

PURPOSE: To investigate the association of HLA class II alleles with pars planitis. METHODS: Blood samples were obtained from 28 patients with pars planitis seen in the Department of Ophthalmology and Visual Sciences and the Barnes Retina Institute at Washington University, St. Louis, Missouri. RESULTS: HLA-DR15, one of the allelic subtypes of HLA-DR2, was present in 18 (64.3%) of 28 patients vs. 10 (20%) of 50 controls (OR = 7.20, CI = 2.28--23.20, P =.0001). HLA-DR51 (HLA-DRB 5) was present in 16 (57.1%) of 28 patients vs. 6 (12%) of 50 controls (OR = 9.78, CI = 2.79--36.42, P =.0001). HLA-DR17 was present in eight (28.6%) of 28 patients vs. one (2%) of 50 controls (OR = 19.60, CI = 2.29--886.7, P =.0001). CONCLUSION: Pars planitis is associated with an increased frequency of the HLA-DR2 suballele, -DR15, HLA-DR51, and HLA-DR17. These results suggest an immunogenic predisposition exists to pars planitis.     

Melatonin synergizes with low doses of L‐DOPA to improve dendritic spine density in the mouse striatum in experimental Parkinsonism

The dopamine precursor, L‐3,4‐dihydroxyphenylalanine (L‐DOPA), is the preferred drug for Parkinson's disease, but long‐term treatment results in the drug‐induced dyskinesias and other side effects. This study was undertaken to examine whether melatonin could potentiate low dose L‐DOPA effects in 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced experimental parkinsonism. Mice were treated with the parkinsonian neurotoxin, MPTP, and different doses of melatonin and low doses of L‐DOPA. Behavior, striatal histology, and dopamine metabolism were evaluated on the 7th day. MPTP‐induced striatal dopamine loss was not modified by melatonin administration (10–30 mg/kg; i.p. at 10‐hr intervals, 6 times; or at 2‐hr intervals, by day). However, low doses of L‐DOPA (5 mg/kg, by oral gavage) administered alone or along with melatonin (10 mg/kg, i.p.) twice everyday for 2 days, 10 hr apart, after two doses of MPTP significantly attenuated striatal dopamine loss and provided improvements in both catalepsy and akinesia. Additionally, Golgi‐impregnated striatal sections showed preservation of the medium spiny neurons, which have been damaged in MPTP‐treated mouse. The results demonstrated that melatonin, but not L‐DOPA, restored spine density and spine morphology of medium spiny neurons in the striatum and suggest that melatonin could be an ideal adjuvant to L‐DOPA therapy in Parkinson's disease, and by the use of this neurohormone, it is possible to bring down the therapeutic doses of L‐DOPA.     

5-Hydroxytryptamine in the phrenic nerve diaphragm: evidence for its existence and release

Evidence is presented for the existence of 5-hydroxytryptamine (5-HT) within the phrenic nerve of the rat and its release following electrical stimulation. Contents of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in the phrenic nerve and the indoleamine released into the bathing fluid were estimated fluorimetrically after isolation on Sephadex G-10 and/or solvent-solvent extraction. Bioassays of 5-HT were done on rat fundus strip. The phrenic nerve and the end-plate zone contains high levels of 5-HT (1.9 micrograms/g wet weight) and 5-HIAA (1.5 micrograms/g wet weight). The resting release of around 1 ng 5-HT/diaphragm/min was enhanced by 50% (1.5 ng 5-HT/diaphragm/min) upon supramaximal (2-4 V) electrical stimulation of 5 Hz. Phrenic nerve diaphragm prepared from the denervated and p-chlorophenylalanine (300 mg/kg/day i.p. for 3 days) treated rats failed to release 5-HT confirming the neuronal origin and the identity of the indoleamine respectively. Furthermore, methysergide, an antagonist of 5-HT in rat fundus strip, blocked the response obtained by the sample on it. A modulatory role of 5-HT in the phrenic nerve diaphragm of the rat is envisaged from the present study.     

Biochemical nature of the prostate-associated antigen identified by the monoclonal antibody, KR-P8

The KR-P8 monoclonal antibody identifies an organ-specific antigen that is associated with normal as well as malignant specimens of human prostate tissue. The antigen is secreted by cells of the prostate and is present in samples of seminal plasma. Data presented here describe the biochemical nature of the antigen that is recognized by KR-P8 as it occurs in seminal plasma and in extracts prepared from cells of the prostate tumor line, PC3. Antigen contained in seminal plasma migrated as a broad band on SDS-polyacrylamide gels in the molecular weight range of 48,000-75,000 d. A similar pattern was observed for antigen prepared from detergent extracts of PC3 cells. The antigen was found to be sensitive to treatment with trypsin and chymotrypsin and the contribution of carbohydrate residues to the structure of the molecule was shown by studies that demonstrated binding of the antigen to Concanavalin A and Soybean Agglutinin lectins. Loss of antigenicity subsequent to periodate oxidation suggested that carbohydrate units are involved in the recognition site for KR-P8 on the antigen.