Long Terminal Repeat Sequence Analysis of HTLV-2 Molecular Variants Identified in Southern Brazil

In Brazil, human T-lymphotropic virus type 2 (HTLV-2) is endemic in Amerindians and epidemic in intravenous drug users (IDUs). The long terminal repeat (LTR) is the most divergent genomic region of HTLV-2, therefore useful to characterize subtypes. Nucleotide sequence and restriction fragment length polymorphism (RFLP) analysis of LTR genomic segments of fourteen HTLV-2 strains isolated from HIV-infected patients of Londrina, Southern Brazil, were carried out. Molecular analysis disclosed that all HTLV-2 strains belonged to 2a subtype, and RFLP detected the presence of the a4, a5, and a6 subgroups according to Switzer's nomenclature. RFLP correlated with nucleotide sequence, and phylogenetic analysis clustered HTLV-2 sequences of IDUs into subgroups a5 and a6. HTLV-2 sequences from individuals of sexual risk factor clustered into the a4 subgroup. These results extend the knowledge of the genetic diversity of HTLV-2 circulating in Brazil and provide insights into HTLV-2 transmission and virus movement in this geographic area.

STANDARDIZATION OF SOME ELECTROCARDIOGRAPHIC PARAMETERS OF CAPTIVE LEOPARD CATS (LEOPARDUS TIGRINUS)

Thirty-three captive leopard cats, Leopardus tigrinus, were anesthetized with xylazine (1-2 mg/kg) and ketamine (10 mg/kg), and electrocardiograph (ECG) tests were recorded in all leads with 1 cm = 1 mV sensibility and 25 mm/sec speed repeating DII lead at 50 mm/sec speed with the same sensibility. Results expressed by mean and standard deviation were: heart rate (HR) = 107 +/- 17 (bpm); P-wave = 0.048 +/- 0.072 (s) x 0.128 +/- 0.048 (mV); PR interval = 0.101 +/- 0.081 (s); QRS compound = 0.053 +/- 0.012 (s) x 1.446 +/- 0.602 (mV); QT interval = 0.231 +/- 0.028 (s); R-wave (CV(6)LL) = 1.574 +/- 0.527 (mV); R-wave (CV(6)LU) = 1.583 +/- 0.818 (mV); heart rhythm: normal sinus rhythm (15.2%), sinus rhythm with wandering pacemaker (WPM) (60.6%), sinus arrhythmia with WPM (24.2%); electric axis: between +30 degrees and +60 degrees (6.1%), +60 (6.1%), between +60 degrees and +90 degrees (57.6%), +90 degrees (9%), between +90 degrees and +120 degrees (21.2%); ST segment: normal (75.7%), elevation (18.2%), depression (6.1%); T-wave polarity (DII): positive (100%); T-wave (V(10)): absent (6.1%), negative (63.6%), positive (18.2%), and with interference (12.1%). Through ECG data comparison with other species, unique features of Leopardus tigrinus` (leopard cat) ECG parameters were detected. Some of the study animals presented with an R-Wave amplitude that was indicative of left ventricle overload according to patterns for normal domestic cats (Felis cati). Echocardiographic exams revealed normal heart cavities` function and morphology. The aim of this study was to establish some electrocardiographic parameters of captive L. tigrinus.

Lipoxin A4 is a novel estrogen receptor modulator.

Inflammation is intimately linked with naturally occurring remodeling events in the endometrium. Lipoxins comprise a group of short-lived, nonclassic eicosanoids possessing potent anti-inflammatory and proresolution properties. In the present study, we investigated the role of lipoxin A(4) (LXA(4)) in the endometrium and demonstrated that 15-LOX-2, an enzyme necessary for LX biosynthesis, is expressed in this tissue. Our results establish that LXA(4) possesses robust estrogenic activity through its capacity to alter ERE transcriptional activity, as well as expression of estrogen-regulated genes, alkaline phosphatase activity, and proliferation in human endometrial epithelial cells. Interestingly, LXA(4) also demonstrated antiestrogenic potential, significantly attenuating E2-induced activity. This estrogenic activity was directly mediated through estrogen receptors (ERs). Subsequent investigations determined that the actions of LXA(4) are exclusively mediated through ERα and closely mimic those of the potent estrogen 17β-estradiol (E2). In binding assays, LXA(4) competed with E2 for ER binding, with an IC(50) of 46 nM. Furthermore, LXA(4) exhibited estrogenic activity in vivo, increasing uterine wet weight and modulating E2-regulated gene expression. These findings reveal a previously unappreciated facet of LXA(4) bioactions, implicating this lipid mediator in novel immunoendocrine crosstalk mechanisms.

Analysis of naturally acquired CD4+T-cell responses to MAGE-A3 and MAGE-A4 cancer/testis antigens in patients with resected head and neck squamous cell carcinoma

Despite advances in the medical and surgical treatment of Head and Neck (HN) squamous cell carcinoma (HNSCC), long term survival has remained unchanged in the last 20 years. The obvious limitations of traditional therapeutic options strongly urge the development of novel therapeutic approaches. The molecular cloning of tumor antigens recognized by T lymphocytes in recent years has provided targets for specific immunotherapy. In this regard, frequent expression of Cancer Testis Antigens (CTA) has been repeatedly observed among HN tumors. We analyzed CTA expression in 46 HNSCC patients and found that MAGE-A3 and/or -A4 CTA were positive in over 70% of samples, regardless of the anatomical site of primary tumors in the upper aerodigestive tract. Still, immune responses against these CTA in HNSCC patients have not yet been investigated in detail. In this study we assessed the responsiveness of HNSCC patient's lymphocytes against overlapping peptides spanning the entire MAGE-A3 and -A4 proteins. After depletion of CD4+CD25+ regulatory T cells, and following three rounds of in vitro stimulation with pools of overlapping peptides, peripheral blood mononuclear cells (PBMCs) of HNSCC patients were screened by IFN-g and TNF-a intracellular cytokine staining for reactivity against MAGE-A3 or -A4 derived peptides. Cytokine secreting CD4+ T cells, specific for several peptides, were detected in 7/7 patients. In contrast, only 2/5 PBMC from healthy donors showed weak T cell responses against 2 peptides. CD4+ T cells specific for one epitope MAGE-A3(281-295), previously described as an HLA-DR11 restricted epitope naturally processed and presented by dendritic cells and tumor cells, were detected in two patients. MAGE-A3(161-175) specific CD4+ T cells were found in one patient. Six MAGE-A3 and -A4 new epitopes are being characterized. Together, these data suggest that naturally acquired CD4+ T cell responses against CT antigens occur in vivo in HNSCC patients, providing a rational basis for the use of the identified peptides in vaccination protocols.

The pleiotropic role of lipoxin A4 and its possible therapeutic use in endometriosis

L'endométriose est l'une des principales causes d'infertilité, caractérisée par une croissance ectopique de tissu endométrial. Sa Physiopathologie est encore mal comprise. En utilisant un modèle expérimental murin, nous avons étudié les mécanismes de développement et de progression de l'endométriose ainsi que l'effet d'un traitement systémique avec la lipoxine A4 (LXA4), un médiateur lipidique aux propriétés anti-inflammatoires. Le traitement à la LXA4 réduit de façon significative la taille des lésions endométriotiques et abaisse le taux de cytokines pro-inflammatoires telles que les interleukines (IL)-lß et d'IL-6. Une production aberrante de stéroïdes par les lésions ainsi qu'un contrôle immunitaire défaillant joue un rôle central dans la pathogenèse. LXA4 diminue l'expression du facteur induit par l'hypoxie (HIF)-la et ses gènes cibles, comme le facteur de croissance de Pendothélium vasculaire (VEGF) et la cyclo-oxygénase (COX)-2, qui diminue la production locale de Prostaglandines E2 ce qui résulterait en un environnement hypo-oestrogénique peritonéal. Outre ses effets anti¬inflammatoires, LXA4 régule l'expression des enzymes de remodelage de la matrice tels les métalloprotéinases matricielles (MMP)-2 et -9 ainsi que le facteur de croissance de transformation (TGF)-ß dans les lésions et les cellules du liquide péritonéal. De plus, le traitement à la LXA4 diminue l'expression de l'aromatase (CYP19A1) ainsi que celle du récepteur des oestrogènes (ER)-a qui module la signalisation des oestrogènes et des gènes impliqués dans la prolifération cellulaire (GREB1, cMyc et CCND1). Finalement, lorsque la LXA4 est donnée après l'apparition de la maladie, le traitement est encore efficace sur le contrôle de la croissance des lésions. En conclusion, ces nouvelles découvertes mettent en valeur un répertoire potentiel de cibles pour le traitement de l'endométriose et confirment un effet pléiotrope du traitement à la LXA4 sur la progression de la maladie : en diminuant les médiateurs pro-inflammatoires et angiogéniques, les enzymes de remodelage de la matrice, ainsi que le métabolisme et la signalisation de l'oestrogène, et en intervenant en aval de la cascade de gènes impliqués dans la prolifération. Ainsi, nos résultats désignent LXA4 comme agent thérapeutique potentiel pour le traitement de l'endométriose péritonéale.

De dominio eminente, ex dicto Matth. XXI. com. 2. minime probato

Dedicatio: Gabriel Serelius.