Vaccine-Induced Linear Epitope-Specific Antibodies to Simian Immunodeficiency Virus SIVmac239 Envelope Are Distinct from Those Induced to the Human Immunodeficiency Virus Type 1 Envelope in Nonhuman Primates

To evaluate antibody specificities induced by simian immunodeficiency virus (SIV) versus human immunodeficiency virus type 1 (HIV-1) envelope antigens in nonhuman primate (NHP), we profiled binding antibody responses to linear epitopes in NHP studies with HIV-1 or SIV immunogens. We found that, overall, HIV-1 Env IgG responses were dominated by V3, with the notable exception of the responses to the vaccine strain A244 Env that were dominated by V2, whereas the anti-SIVmac239 Env responses were dominated by V2 regardless of the vaccine regimen.     

Evaluation of the <Emphasis Type="Italic">OPTC</Emphasis> gene in primary open angle glaucoma: functional significance of a silent change

Background  

We investigated the molecular basis of primary open-angle glaucoma (POAG) using Opticin (OPTC) as a candidate gene on the basis of its expression in the trabecular meshwork cells involved in the disease pathogenesis. Two hundred POAG patients and 100 controls were enrolled in this study. The coding sequence of OPTC was amplified by PCR from genomic DNA of POAG patients, followed by SSCP, DHPLC and DNA sequencing. Subsequent bioinformatic analysis, site-directed mutagenesis, quantitative RT-PCR and western blot experiments were performed to address the functional significance of a 'silent' change in the OPTC coding region while screening for mutations in POAG patients.     

Protective effects of combining monoclonal antibodies and vaccines against the Plasmodium falciparum circumsporozoite protein

Combinations of monoclonal antibodies (mAbs) against different epitopes on the same antigen synergistically neutralize many viruses. However, there are limited studies assessing whether combining human mAbs against distinct regions of the Plasmodium falciparum (Pf) circumsporozoite protein (CSP) enhances in vivo protection against malaria compared to each mAb alone or whether passive transfer of PfCSP mAbs would improve protection following vaccination against PfCSP. Here, we isolated a panel of human mAbs against the subdominant C-terminal domain of PfCSP (C-CSP) from a volunteer immunized with radiation-attenuated Pf sporozoites. These C-CSP-specific mAbs had limited binding to sporozoites in vitro that was increased by combination with neutralizing human “repeat” mAbs against the NPDP/NVDP/NANP tetrapeptides in the central repeat region of PfCSP. Nevertheless, passive transfer of repeat- and C-CSP-specific mAb combinations did not provide enhanced protection against in vivo sporozoite challenge compared to repeat mAbs alone. Furthermore, combining potent repeat-specific mAbs (CIS43, L9, and 317) that respectively target the three tetrapeptides (NPDP/NVDP/NANP) did not provide additional protection against in vivo sporozoite challenge. However, administration of either CIS43, L9, or 317 (but not C-CSP-specific mAbs) to mice that had been immunized with R21, a PfCSP-based virus-like particle vaccine that induces polyclonal antibodies against the repeat region and C-CSP, provided enhanced protection against sporozoite challenge when compared to vaccine or mAbs alone. Collectively, this study shows that while combining mAbs against the repeat and C-terminal regions of PfCSP provide no additional protection in vivo, repeat mAbs do provide increased protection when combined with vaccine-induced polyclonal antibodies. These data should inform the implementation of PfCSP human mAbs alone or following vaccination to prevent malaria infection.     

Untersuchungen zur Tiergesundheit,Leistung und zum Rückstandsverhalten beim Schwein bei gleichzeitiger Aufnahme der Mykotoxine Ochratoxin A,Deoxynivalenol, Zearalenon über das Futter im 90-Tage-Test

The effect of the administration of the mycotoxins OTA, ZEA and DON alone resp. in combination on animal health and the residue behavior of pigs from 50 – 60 kg living weight over 90 days was investigated in 4 separate studies. Due to its fast metabolisation the administration of 1000 µg DON resp. 250 µg ZEA per kg feed alone or in combination with other mycotoxins does not lead to detectable residues of these mycotoxins in organs and tissues. Therefore these mycotoxins should not be relevant to the consumer.There is an effect of the simultaneous administration of ZEA resp. DON on the metabolisation resp. secretion of OTA. OTA is of relevance from the point of view of residue toxicology.     

Type I IFN induced by adenovirus serotypes 28 and 35 has multiple effects on T cell immunogenicity

Recombinant adenovirus (rAd) vectors are being investigated as vaccine delivery vehicles in preclinical and clinical studies. rAds constructed from different serotypes differ in receptor usage, tropism, and ability to activate cells, aspects of which likely contribute to their different immunogenicity profiles. In this study, we compared the infectivity and cell stimulatory capacity of recombinant adenovirus serotype 5 (rAd5), recombinant adenovirus serotype 28 (rAd28), and recombinant adenovirus serotype 35 (rAd35) in association with their respective immunogenicity profiles. We found that rAd28 and rAd35 infected and led to the in vitro maturation and activation of both human and mouse dendritic cells more efficiently compared with rAd5. In stark contrast to rAd5, rAd28 and rAd35 induced production of IFN-α and stimulated IFN-related intracellular pathways. However, the in vivo immunogenicity of rAd28 and rAd35 was significantly lower than that of rAd5. Deletion of IFN-α signaling during vaccination with rAd28 and rAd35 vectors increased the magnitude of the insert-specific T cell response to levels induced by vaccination with rAd5 vector. The negative impact of IFN-α signaling on the magnitude of the T cell response could be overcome by increasing the vaccine dose, which was also associated with greater polyfunctionality and a more favorable long-term memory phenotype of the CD8 T cell response in the presence of IFN-α signaling. Taken together, our results demonstrate that rAd-induced IFN-α production has multiple effects on T cell immunogenicity, the understanding of which should be considered in the design of rAd vaccine vectors.     

Perforin is required for primary immunity to Histoplasma capsulatum

Protective immunity against primary and secondary infection by the fungus Histoplasma capsulatum (HC) is multifactorial, requiring cells of the innate and adaptive immune response. Effector mechanisms that could mediate intracellular killing of HC include cytokines such as IFN-gamma and TNF-alpha and/or direct cytolytic activity by T and NK cells. In this regard, although previous work has clearly demonstrated a critical role for IFN-gamma and TNF-alpha in limiting fungal growth in primary HC infection, less is known regarding the role of cytolytic mechanisms. The studies reported here first address the role of perforin in mediating immunity to HC. Remarkably, perforin-deficient knockout (PfKO) mice were shown to have accelerated mortality and increased fungal burden following a lethal or sublethal primary challenge. These data established an essential role for perforin in primary immunity systemic HC infection. Interestingly, depletion of CD8(+) T cells in PfKO mice caused a further increase in fungal burden and accelerated mortality, suggesting a perforin-independent role for CD8(+) T cells. Moreover, adoptive transfer of CD8(+) T cells from PfKO mice into IFN-gamma(-/-) mice caused a reduction in fungal burden following infectious challenge compared with control IFN-gamma(-/-) mice. Together, these data suggest that CD8(+) T cells can mediate immunity to HC through both perforin-dependent and -independent mechanisms.     

Toll-like receptor ligands modulate dendritic cells to augment cytomegalovirus- and HIV-1-specific T cell responses

Optimal Ag targeting and activation of APCs, especially dendritic cells (DCs), are important in vaccine development. In this study, we report the effects of different Toll-like receptor (TLR)-binding compounds to enhance immune responses induced by human APCs, including CD123(+) plasmacytoid DCs (PDCs), CD11c(+) myeloid DCs (MDCs), monocytes, and B cells. PDCs, which express TLR7 and TLR9, responded to imidazoquinolines (imiquimod and R-848) and to CpG oligodeoxynucleotides stimulation, resulting in enhancement in expression of costimulatory molecules and induction of IFN-alpha and IL-12p70. In contrast, MDCs, which express TLR3, TLR4, and TLR7, responded to poly(I:C), LPS, and imidazoquinolines with phenotypic maturation and high production of IL-12 p70 without producing detectable IFN-alpha. Optimally TLR ligand-stimulated PDCs or MDCs exposed to CMV or HIV-1 Ags enhanced autologous CMV- and HIV-1-specific memory T cell responses as measured by effector cytokine production compared with TLR ligand-activated monocytes and B cells or unstimulated PDCs and MDCs. Together, these data show that targeting specific DC subsets using TLR ligands can enhance their ability to activate virus-specific T cells, providing information for the rational design of TLR ligands as adjuvants for vaccines or immune modulating therapy.     

Prime-boost vaccination with HIV-1 Gag protein and cytosine phosphate guanosine oligodeoxynucleotide,followed by adenovirus,induces sustained and robust humoral and cellular immune responses

A prophylactic vaccine for HIV-1 will probably require the induction and maintenance of both humoral and cellular immunity. One current strategy to achieve such long term immune responses is a prime-boost vaccination approach using a DNA priming inoculation, followed by recombinant viral boost. In this report we use a novel prime-boost approach in which the priming injections consist of recombinant HIV-1 Gag protein mixed with cytosine phosphate guanosine oligodeoxynucleotide (CpG ODN), followed by recombinant adenoviral boost expressing HIV-1 Gag. Analysis of the immune responses indicates that HIV-1 Gag protein plus CpG ODN immunization alone induces potent humoral as well as Th1 and CD8+ T cell responses. Boosting with recombinant adenovirus strikingly enhances CD8+, but not Th1, T cell responses, resulting in CD8+ T cell responses far greater in magnitude than Th1 responses. Furthermore, the Th1 and CD8+ T cell responses following prime-boost immunization were seen in both lymphoid and peripheral mucosal organs and were sustained over several months. Together, these data suggest a new immunization approach for elicitation of long term humoral and cellular immune responses.