A cross-talk between blood-cell neuroplasticity-related genes and environmental enrichment in working dogs.

This study aims to identify a panel of blood-cell neuroplasticity-related genes expressed following environmental enrichment stimulation (EE). The Drug detection (DD) training course was an excellent model for the study of EE in the working dog. This research is divided into two experimental trials. In the First Trial, we identified a panel of blood-cell neuroplasticity related-genes associated with DD ability acquired during the training course. In the Second Trial, we assessed the EE additional factor complementary feeding effect on blood-cell neuroplasticity gene expressions. In the First and Second Trials, at different time points of the DD test, blood samples were collected, and NGF, BDNF, VEGFA, IGF1, EGR1, NGFR, and ICE2 blood-cell neuroplasticity related-genes were analyzed. As noted in the First Trial, the DD test in working dogs induced the transient up-regulation of VEGFA, NGF, NGFR, BDNF, and IGF, immediately after the DD test, suggesting the existence of gene regulations. On the contrary, the Second Trial, with feeding implementation, showed an absence of mRNA up-regulation after the DD test. We suppose that complementary feeding alters the systemic metabolism, which, in turn, changes neuroplasticity-related gene blood-cell mRNA. These findings suggested that, in working dogs, there is a cross-talk between blood-cell neuroplasticity-related genes and environmental enrichment. These outcomes could be used to improve future treatments in sensory implementation.

Combined treatment with nicotinamide and desferrioxamine prevents islet allograft destruction in NOD mice.

Nonobese diabetic (NOD) mice get spontaneous diabetes with clinical and pathological manifestations similar to those seen in human type I diabetes. NOD mice will destroy transplants of treated allogeneic islet tissue by a recurrence of the disease process that destroyed the original islet tissue. This may be prevented by treatment of the animals with combined desferrioxamine and nicotinamide. Transplanted animals become normoglycemic and remain so for the duration of the treatment. This suggests that oxygen-derived free radicals may be involved in islet damage in spontaneous diabetes.

Neutralizing antibodies are positively associated with CD4+ T-cell counts and T-cell function in long-term AIDS-free infection.

OBJECTIVES: To assess the dynamics of neutralizing antibodies (NAb) in long-term AIDS-free HIV-1-infected subjects and establish correlations with known markers of disease progression. DESIGN: Cross-sectional study using sera collected from long-term non-progressors (LTNP) 8 years after seroconversion or study entry. Longitudinal study using sera collected from LTNP at 0, 0.5, 1, 2, 4, 6, 8 and 10 years after seroconversion and, as controls, from rapid progressors. METHODS: Individuals with documented AIDS-free HIV-1 infection for at least 8 years were evaluated for NAb against five heterologous HIV-1 primary isolates. In the cross-sectional study, serum viral RNA levels, CD4+ T-cell numbers and T-cell function were determined on samples collected during the eighth year of follow-up. For the longitudinal study, NAb were assessed in sequential sera taken from LTNP and rapid progressors. RESULTS: Serum neutralization titres found in individual sera differed from one HIV-1 isolate to another, were detected in 49-76% of LTNP, without correlation with the coreceptor usage of the isolate, and were positively associated with CD4+ T-lymphocyte counts (P = 0.0041) and T-cell function (P = 0.04). No correlation was found between NAb and the level of viral RNA in serum or the rate of CD4+ T-cell decline. Longitudinal analysis of sera from LTNP and rapid progressors showed that although several subjects in both groups had neutralizing activity at seroconversion, it thereafter became lower or no longer detectable. NAb were again found 1-4 years later and stably persisted in LTNP, but remained undetectable or at low levels in rapid progressors. CONCLUSIONS: NAb were preferentially found in subjects with relatively preserved T-cell function and CD4+ T-cell numbers. In these individuals, neutralizing activity against heterologous isolates increased with time. These data suggest that the capacity to produce broadly NAb is a function of the integrity of the immune system.

Lymphoproliferative response to HIV type 1 p24 in long-term survivors of HIV type 1 infection is predictive of persistent AIDS-free infection.

To establish immunologic correlates of progression to AIDS in long-term survivors of HIV-1 infection, HIV-1-specific T cell-mediated responses, together with T cell reactivity to recall antigens, were studied in frozen samples collected after 5 and 8 years of documented HIV-1 infection. Eight of 21 homosexual men, who remained asymptomatic and maintained CD4+ T cell numbers >400 cells/microl for 9 years of HIV-1 infection, progressed to AIDS (CDC 1993 definition) within 12.5 years of infection (late progressors, LPs). The remainders showed minimal deterioration of immune parameters (long-term nonprogressors, LTNPs). CD4+ T cell numbers and T cell function measured at years 5 and 8 of follow-up were comparable in the two groups. At both time points responses to recall antigens did not significantly differ between the two groups, although a significant decline of lymphoproliferative responses to Candida and tetanus toxoid was observed in LPs. Circulating HIV-1-specific cytotoxic T lymphocyte precursors were found in broad frequency ranges in both LPs and LTNPs and, similarly, no significant differences were found in comparing the breadth of serum neutralizing activity against heterologous HIV-1 primary isolates. In contrast, lymphoproliferative responses to p24gag, but not p17gag or gp160env, were detected only in LTNPs and were totally absent in LPs at both time points (p < 0.01). Our data suggest that the presence of circulating p24-specific CD4+ T cells may reflect effective viral control and be predictive of subsequent favorable clinical course in long-term asymptomatic individuals.

Response to hepatitis B vaccine in a cohort of Gambian children.

In a cohort of 1000 Gambian children immunized with four doses of 10 micrograms of plasma-derived hepatitis B virus vaccine, 44 subjects (4.4%) showed no response (< 10 mIU/ml; 6 subjects) or low specific antibody response (10 to 99 mIU/ml; 38 subjects) to hepatitis B surface antigen. Serologic indices, potentially correlated with low immunologic response, were investigated in sera obtained from these children and in sex-, age- and village-matched controls who showed a normal response. The presence of circulating immune complexes in similar proportion of responding and poorly responding children together with a low prevalence of rheumatoid factors suggested that polyclonal B cell activation was not correlated with the subnormal humoral response. Concentrations of serum immunoglobulin (Ig) and IgG subclasses did not differ in the two groups. Some of the African prevalent Ig allotypes were determined, but no significant differences in the two groups were found. The humoral response to hepatitis B surface antigen did not correlate with the response to tetanus toxoid.

Vandetanib: An overview of its clinical development in NSCLC and other tumors.

Vandetanib is an oral inhibitor of vascular endothelial growth factor receptor 2 (VEGFR-2), epidermal growth factor receptor (EGFR) and Ret tyrosine kinases involved in tumor growth, progression and angiogenesis. Phase I studies indicated that the recommended dose of vandetanib as a single agent is 300 mg/day. Rash, diarrhea, hypertension and asymptomatic Q-Tc prolongation were the most common adverse events. Four randomized phase III clinical trials evaluated the efficacy of vandetanib in non-small cell lung cancer (NSCLC) in combination with docetaxel (ZODIAC), pemetrexed (ZEAL) or as a single agent (ZEST and ZEPHYR). Only the ZODIAC trial met its primary endpoint (progression-free survival [PFS]), while no study showed an advantage in overall survival with vandetanib. No significant antitumor activity has been observed in small cell lung cancer, advanced ovarian, colorectal, breast, prostate cancer and multiple myeloma. In advanced metastatic medullary thyroid cancer, one randomized phase III clinical trial has demonstrated that vandetanib can significantly improve response rate, PFS and time to worsening of pain. Several key questions remain to be addressed regarding the identification of clinical or molecular biomarkers predictive of response, the choice of the optimal dose or schedule of vandetanib and the safety of long-term administration. The results of ongoing trials in untreated patients with advanced NSCLC and other tumors should better define the optimal clinical application of vandetanib.

Lymphocytic traffic and homing into target tissue and the generation of endocrine autoimmunity.

Endocrine autoimmunity is known to be characterized by the presence of specific autoantibodies and from the histopathological point of view by lymphocytic infiltration in the target tissue. The presence of mononuclear cell infiltrates is the pathological hallmark of most endocrine diseases characterized by an autoimmune process directed against antigens expressed on endocrine cells. Infiltrating cells can usually be detected by biopsy or by using other, non-invasive, techniques. However, in endocrine tissue such as the islets of Langerhans and the adrenal glands it is difficult to perform biopsies and diagnosis of the autoimmune process is dependent mainly upon detection of specific autoantibodies. A crucial aspect of endocrine autoimmunity and of all processes of organ specific autoimmunity is why and how lymphocytes migrate from primary lymphoid tissue to their specific targets. This occurs mainly through contact with specific adhesion molecules which enable lymphocytes to adhere to the endothelial vessels in close proximity to the target tissue. In this review we discuss the homing of peripheral mononuclear cells into target endocrine tissues and the mediating role of adhesion molecules.

T-lymphocyte subpopulations in insulin-dependent (type I) diabetes mellitus.

Initial reports of blood T cell subsets in insulin-dependent (type I) diabetes mellitus (IDDM) are conflicting and, consequently, difficult to relate to animal models of the disease. To minimize technical artefacts, which may have contributed to previous results, we used direct immunofluorescence on whole blood and counted 3,000 lymphocytes by flow cytometer. Forty-two IDDM patients divided in three groups of 14 according to the disease duration and 12 age and sex matched controls were studied for T3, T4, T8 and HLA-DR expression. No statistically significant differences were found in their total blood lymphocyte counts or in the percentage of T3, T4 and T8 positive cells, although mild lymphopenia was found in the group of long-standing diabetics. The percentage of activated T cells, identified as T3+/DR+ cells, was significantly increased in the groups of patients studied more than a month after diagnosis and in four of 14 patients studied within a month from diagnosis. Seven new onset IDDM patients were studied for co-expression of T8 and Leu 15 antigens (putative suppressor cell phenotype), but no significant differences was found compared with controls. We conclude that T4/T8 ratio abnormalities previously reported in Ficoll separated cells are not reproduced when unseparated cells are analysed by flow cytometry, although the presence of HLA-DR+ T cells is confirmed.

Desferoxamine blocks IL 2 receptor expression on human T lymphocytes.

Thymidine uptake by PHA-stimulated human lymphocytes is reduced in the presence of 100 microM or greater concentrations of the iron-chelating agent desferoxamine (DF). We assessed expression of IL 2 receptor, 4F2 and Ia antigens, IL 2 production, and cell cycle progression by blood mononuclear cells (MNC) stimulated by PHA in the presence or absence of DF to determine whether the lack of T cell proliferation was a manifestation of inhibition of an earlier activation event. Tac antigen expression on PHA-stimulated MNC was inhibited by DF throughout 8 days of culture, and those cells which were positive had a low density of Tac antigen as compared with controls without DF. Expression of other activation antigens, 4F2 and Ia, was not impaired by DF. The supernatants of the DF-containing and control cultures contained equivalent IL 2 activity, as measured on the HT-2 cell line. Cell cycle analysis of these cultures shows that the addition of DF at the beginning of culture blocks most cells from undergoing G0 to G1 transition, whereas later addition of DF arrests the progression of the T cell blasts through the cell cycle. Separation of cells cultured with PHA and DF into Tac+ and Tac- subsets showed that progression from G0 to G1 was restricted to the former subset. These results suggest that interference with IL 2 receptor expression might contribute to the block in mitogen-induced proliferation caused by DF.

Processing and presentation of cell-associated varicella-zoster virus antigens by human monocytes.

To determine whether viral antigens associated with infected cells were processed for presentation to T cells, we cultured human blood mononuclear cells (MNC) from varicella-zoster virus (VZV) immune donors with VZV-infected fibroblasts of known HLA type which had been fixed in 0.05% glutaraldehyde. After 7-8 days of culture thymidine uptake by T4+ cells exceeded that of T8+ cells. Stimulated cells were depleted of adherent cells and restimulated with VZV-infected fibroblasts from donors matched or unmatched with the responder for HLA type in the presence or absence of fresh adherent cells. Proliferation of the VZV-specific blasts required the presence of adherent cells matched with the responder lymphocytes for HLA-DR; conversely, the VZV specific response was not restricted by the MHC of the fibroblasts used in the restimulation assay. Preincubation of the adherent cells with chloroquine inhibited the proliferative response in a dose-dependent manner. These results suggest that VZV antigens on infected cells may be processed by monocytes for presentation to T cells.

Circulating lymphocyte populations and autoantibodies in non-obese diabetic (NOD) mice: a longitudinal study.

Several previous observations indicate a role for the immune system in the pathogenesis of insulin-dependent diabetes mellitus (IDDM) in non-obese diabetic (NOD) mice. In order to assess the status of the immune system in this model of spontaneous diabetes we studied the phenotype of circulating lymphocytes and the humoral autoimmunity to islet cells in non-diabetic NOD mice at various ages. Lymphocyte numbers were low in young NOD mice (age less than 160 days) as compared with other strains of mice and increased later to reach values in or above the range of controls. The percentages of circulating T lymphocytes and their L3T4+ and Lyt2+ subsets were higher in NOD mice of all ages and both sexes than in controls; however, no imbalance of the L3T4+ and Lyt2+ subpopulations was found. Anti-insulin autoantibodies were detected by an ELISA assay in all the NOD mice studied throughout the entire period of observation. Autoantibodies reacting with the cytoplasm of islet cells in Bouin's fixed pancreas sections, likely to be anti-insulin antibodies, were found in 47 to 58% of the samples from NOD mice aged 75 to 150 days. Antibodies to surface antigens of rat insulinoma cells were virtually absent in young NOD mice (75-100 days) and appeared in 33 to 43% of the samples from 150 to 185 days old NOD mice. The autoantibodies and the quantitative lymphocyte abnormalities reported here, although not predictive of the appearance of overt diabetes, are likely to be involved in the pathogenesis of the disease and therefore may indicate directions for future investigations.

A cytotoxic monoclonal islet cell surface antibody from the NOD mouse.

Monoclonal antibody (Mab) 1.93B7 was obtained by fusion of spleen cells from a diabetic NOD mouse with P3X63Ag8.653 myeloma cells and screening for complement mediated lysis of rat insulinoma (RIN) cells. Immunofluorescence studies revealed that this Mab binds to RIN cells but not to the rat pituitary tumour line GH3. The binding of Mab 1.93B7 to RIN cells was abolished by trypsin but not by neuraminidase treatment of the cells, suggesting that the antigen recognized is a protein. Mab 1.93B7 bound to approximately 30% of mouse (BALB/c) and rat islet cells which had been subjected to trypsin digestion and incubated as a single cell suspension for 12h to allow reexpression of trypsin sensitive antigens. Since Mab 1.93B7 is potentially pathogenic, as suggested by its reactivity to primary islet cells and its complement fixing capacity, we injected it into BALB/c and NOD mice. Cytotoxic activity against RIN cells was detected in the serum of the animals injected with Mab 1.93B7, but the Mab did not exert a diabetogenic action and failed to reverse diabetes when administered at onset in NOD mice. No modification of the course of spleen cell mediated transfer of diabetes in NOD mice was observed when the Mab was administered from the time of spleen cell inoculation to the appearance of glycosuria. The implications of the lack of an effect in vivo of Mab 1.93B7 under the conditions employed are discussed.

Chromosome walking on the TCL1 locus involved in T-cell neoplasia.

The TCL1 locus on chromosome 14 band q32.1 is frequently involved in the chromosomal translocations and inversions with the T-cell receptor genes observed in several T-cell tumors, including T-prolymphocytic leukemias, acute and chronic leukemias associated with the immunodeficiency syndrome ataxia-telangiectasia, and adult T-cell leukemia. All breakpoints cloned in this area have been mapped to 14q32.1, an area distant approximately 10,000 kb from the immunoglobulin heavy-chain gene locus on chromosome 14q band 32.3. Except for two cases of inversion, no physical linkage of the cloned breakpoints has been reported, nor has a gene been identified in this region. Taking advantage of chromosome-walking techniques and of the P1 phage, we cloned and characterized 450 kb of the germ-line TCL1 locus, starting from the breakpoints of two independent T-cell leukemias. We show that all molecular rearrangements characterized so far map to these clones, indicating not only that this region is the target of chromosomal rearrangements occurring in this area but also that both inversion and translocations occur within a 300-kb region in the T-cell leukemias. In the attempt to identify a candidate oncogene responsible for the malignant transformation, a CpG island centromeric to the inversions and to the translocations has been identified. Two probes near the CpG island have detected sequences conserved among species, as well as two transcripts in the K562 human erythroleukemia cell line. On the basis of these data, a model of activation of the putative TCL1 oncogene is suggested.