Susceptibility of diverse primary HIV isolates with varying co-receptor specificity's to CXCR4 antagonistic compounds

The chemokine receptors CCR5 and CXCR4 are an obvious target for HIV therapies. Two compounds, T-22 and AMD-3100, have been shown to inhibit infection of CXCR4-using HIV-1 isolates. The specificity of T-22 and AMD-3100 was further confirmed by their ability to block entry of HIV-1 in GHOST-CXCR4 transfected cells with no effect on viral entry in the GHOST-CCR5 cells. The ability of T-22 to block replication of diverse HIV-1 isolates (group M, subtypes A, B, D, E, and F as well as group O) and HIV-2 primary isolates with varying coreceptor specificities ranging from exclusive CCR5 usage to multiple coreceptor usage was examined in detail. T-22 was found to be highly effective (>90%) at blocking infection of diverse HIV-1 (subtypes A-F, and group O) and HIV-2 isolates that use multiple coreceptors in human PBMCs homozygous for a 32-bp deletion in CCR5 (CCR5-/-), but less effective in CCR5 +/+ PBMCs. Additionally, sequential primary HIV-1 isolates obtained from a longitudinal cohort who had switched from single coreceptor usage to a broad range of multiple receptors could be blocked effectively by both T-22 and AMD-3100 in CCR5-/- PBMCs. Our data suggest that CXCR4 antagonistic compounds are highly effective in blocking the entry of X4-tropic HIV-1, and that these compounds could be a useful additive to current anti-retroviral therapy for clinical management of HIV disease.     

Bilateral cataract and high serum ferritin: a new dominant genetic disorder?

This paper reports the cosegregation in a three generation pedigree of dominantly inherited cataract with an abnormally high level of serum ferritin. In this family, circulating L ferritin was raised in all subjects affected by cataract independently of iron overload. We suggest that a disorder of ferritin metabolism could be a new genetic disorder leading to lens opacity. Cataract-hyperferritaemia syndrome could also be a new contiguous gene syndrome involving the L ferritin gene and the gene coding for the lens membrane protein (MP19), which both map to the same region of chromosome 19q.     

Acquisition of vimentin in astrocytes cultured from postnatal rat brain

Summary Vimentin and glial fibrillary acidic protein (GFAP) represent the principal constituents of intermediate filaments found in astrocytes. In contrast to vimentin—GFAP transition which occurs during glial developmentin situ, vimentin coexists with GFAP in cortical astrocytes allowed to differentiate in culture. To examine whether culture conditions or proliferative activity of the cells is responsible for the expression of vimentin, we generated cultures of GFAP-positive, vimentin-negative astrocytes isolated from 26-day postnatal rat brain cortices. Isolated astrocytes are characterized by a very thin rim of perinuclear cytoplasm and by numerous processes. Antiserum to GFAP labelled major processes and cell somata of some astrocytes, especially those with relatively short and large processes. Within 3 days in culture, all astrocytes accumulated GFAP in hypertrophic cell bodies and many began to express vimentin. Vimentin appeared primarily close to nuclei, and filaments of vimentin extended into proximal segments of the cell processes. In some astrocytes, however, vimentin was always absent. Combined double immunolabelling and histoautoradiography experiments demonstrated that the acquisition of vimentin was independent of the ability of astrocytes to incorporate tritiated thymidine. The results indicate that astrocytes isolated from 26-day postnatal rat brain are heterogeneous with respect to their ability to express vimentin and that vimentin synthesis is not correlated with the growth state of the cells as had been previously suspected.     

Murine Dendritic Cells Pulsed In Vitro with Toxoplasma gondii Antigens Induce Protective Immunity In Vivo

The activation of a predominant T-helper-cell subset plays a critical role in disease resolution. In the case of Toxoplasma gondii, the available evidence indicates that CD4⁺ protective cells belong to the Th1 subset. The aim of this study was to determine whether T. gondii antigens (in T. gondii sonicate [TSo]) presented by splenic dendritic cells (DC) were able to induce a specific immune response in vivo and to protect CBA/J mice orally challenged with T. gondii cysts. CBA/J mice immunized with TSo-pulsed DC exhibited significantly fewer cysts in their brains after oral infection with T. gondii 76K than control mice did. Protected mice developed a strong humoral response in vivo, with especially high levels of anti-TSo immunoglobulin G2a antibodies in serum. T. gondii antigens such as SAG1 (surface protein), SAG2 (surface protein), MIC1 (microneme protein), ROP2 through ROP4 (rhoptry proteins), and MIC2 (microneme protein) were recognized predominantly. Furthermore, DC loaded with TSo, which synthesized high levels of interleukin-12 (IL-12), triggered a strong cellular response in vivo, as assessed by the proliferation of lymph node cells in response to TSo restimulation in vitro. Cellular proliferation was associated with gamma interferon and IL-2 production. Taken together, these results indicate that immunization of CBA/J mice with TSo-pulsed DC can induce both humoral and Th1-like cellular immune responses and affords partial resistance against the establishment of chronic toxoplasmosis.     

Pneumococcal serotype 19F conjugate vaccine induces cross-protective immunity to serotype 19A in a murine pneumococcal pneumonia model

Immunization with a pneumococcal conjugate vaccine (PNC) containing serotype 19F induces cross-reactive antibodies to 19A in mice and human infants. Active immunization with PNC and passive immunization with serum samples from infants vaccinated with PNC containing serotype 19F, but not serotype 19A, protected against lung infection caused by both serotypes in a murine model.     

Haplotype analysis of the BRCA2 9254delATCAT recurrent mutation in breast/ovarian cancer families from Spain

A frame-shift 9254del5 mutation was independently identified in 12 families, eleven of them with Spanish ancestors, in a BRCA2 screening performed in 841 breast and/or ovarian cancer families and in 339 women with breast cancer diagnosed before the age of 40 at different centers in France and Spain. We sought to analyze in detail the haplotype and founder effects of the 9254del5 and to estimate the time of origin of the mutation. Eight polymorphic microsatellite markers and two BRCA2 polymorphisms were used for the haplotype analyses. The markers were located flanking the BRCA2 gene spanning a region of 6.1 cM. Our results suggest that these families shared a common ancestry with BRCA2 9254del5, which is a founder mutation originating in the Northeast Spanish, with an estimated age of 92 (95% CI 56-141) generations.     

Lipoteichoic acids from Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 antagonize the responsiveness of human intestinal epithelial HT29 cells to lipopolysaccharide and gram-negative bacteria

Intestinal epithelial cells (IECs) respond to lipopolysaccharide (LPS) from gram-negative bacteria in the presence of the soluble form of CD14 (sCD14), a major endotoxin receptor. Since sCD14 is also known to interact with gram-positive bacteria and their components, we looked at whether sCD14 could mediate their effects on human IECs. To this end, we examined the production of proinflammatory cytokines following exposure of the IECs to specific gram-positive bacteria or their lipoteichoic acids (LTAs) in the absence and presence of human milk as a source of sCD14. In contrast to LPS from Escherichia coli or Salmonella enteritidis, neither the gram-positive bacteria Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 nor their LTAs stimulated IECs, even in the presence of sCD14. However, both LTAs inhibited the sCD14-mediated LPS responsiveness of IECs. We have previously hypothesized that sCD14 in human milk is a means by which the neonate gauges the bacterial load in the intestinal lumen and liberates protective proinflammatory cytokines from IECs. The present observations suggest that gram-positive organisms, via their LTAs, temper this response and prevent an exaggerated inflammatory response.     

Role of CD40 antigen and interleukin-2 in T cell-dependent human B lymphocyte growth

In the present study, we examined the participation of CD40 ligand (L)-CD40 interaction in T cell-dependent B cell responses. To this end, purified B lymphocytes were cultured over irradiated CD4⁺ cloned T cells activated with immobilized anti-CD3 antibody. The anti-CD40 mAb 89 strongly blocked, in a specific fashion, both proliferation and Ig secretion of tonsil B cells. Interestingly, proliferation of surface (s)IgD⁺ B cell was significantly less inhibited by anti-CD40 than that of sIgD^? cells. Preactivated T cells induced B cells to grow and secrete immunoglobulins preferentially in response to IL-2. This contrasts with the CD40 system where B cells are essentially responsive to IL-4 and IL-10 but not to IL-2 alone. Collectively, these data indicate that CD40L-CD40 interaction plays an important role in IL-2-mediated T cell-dependent B cell responses. However, the activation of a subset of sIgD⁺ cells may be independent of this interaction.     

Effects of long-term lamivudine therapy in renal-transplant patients.

BACKGROUND: Following renal transplantation (RT), chronic immunosuppression is associated in hepatitis B virus (HBV) (+) patients with a flare-up of the disease, which might be harmful in the long term. OBJECTIVES: We report on the effect of long-term lamivudine therapy given at an initial daily dose of 100mg in 18 HBV (+) RT patients. RESULTS: When lamivudine therapy was commenced, 14 patients (77%) had an increase in their aspartate (AST) and alanine (ALT) aminotransferase levels. During a mean follow-up, under treatment, of 36.5 +/- 3.5 months (up to 66 months), 10 patients (55%) had a sustained partial (HBV DNA < 4 x 10(5)copies/ml) (n = 4) or complete (HBV DNA < 400 copies/ml) (n = 6) virological response. Overall, 12 virological breakthroughs were observed. Of those who were HBe Ag(+) prior to lamivudine therapy (n = 4), one seroconverted to HBe Ab during therapy. At the last follow-up, AST and ALT levels were normal in 13 patients. When liver biopsy was repeated during treatment (n = 15), the virological responders showed a significant decrease in total Knodell score from 10 +/- 0.6 to 7 +/- 1 (P = 0.04), but no significant change in the stage of fibrosis. Conversely, in those patients with high HBV DNA titers, there were no significant changes in the total Knodell score or in the grade of fibrosis. CONCLUSION: In conclusion, lamivudine therapy is safe in HBV(+)ve renal-transplant patients. However, even if the full and partial virological response rates are still high (55%) in the long term, relapse or primary non-responses occur. The implementation of alternative efficient strategies is warranted.