An optimally effective AIDS vaccine would likely require the induction of both neutralizing antibody and cell-mediated immune responses, which has proven difficult to obtain in previous clinical trials. Here we report on the induction of human immunodeficiency virus type-1 (HIV-1)-specific immune responses in healthy adult volunteers that received the multi-gene, polyvalent, DNA prime–protein boost HIV-1 vaccine formulation, DP6-001, in a Phase I clinical trial. Robust cross-subtype HIV-1-specific T cell responses were detected in IFN-γ ELISPOT assays. Furthermore, we detected high titer serum antibody responses that recognized a wide range of primary HIV-1 Env antigens and also neutralized pseudotyped viruses that express the primary Env antigens from multiple HIV-1 subtypes. These findings demonstrate that the DNA prime–protein boost approach is an effective immunization method to elicit both humoral and cell-mediated immune responses in humans, and that a polyvalent Env formulation could generate broad immune responses against HIV-1 viruses with diverse genetic backgrounds.

An optimally effective AIDS vaccine would likely require the induction of both neutralizing antibody and cell-mediated immune responses, which has proven difficult to obtain in previous clinical trials. Here we report the induction of Human Immunodeficiency Virus Type-1 (HIV-1)-specific immune responses in healthy adult volunteers that received the multi-gene, polyvalent, DNA prime-protein boost HIV-1 vaccine formulation, DP6−001 in a Phase I clinical trial conducted in healthy adult volunteers of both genders. Robust cross-subtype HIV-1-specific T cell responses were detected in IFNγ ELISPOT assays. Furthermore, we detected high titer serum antibody responses that recognized a wide range of primary HIV-1 Env antigens and also neutralized pseudotyped viruses that express the primary Env antigens from multiple HIV-1 subtypes. These findings demonstrate that the DNA prime-protein boost approach is an effective immunization method to elicit both humoral and cellmediated immune responses in humans, and that a polyvalent Env formulation could generate broad immune responses against HIV-1 viruses with diverse genetic backgrounds.

A major challenge in developing an HIV-1 vaccine is to identify immunogens and their delivery methods that can elicit broad neutralizing antibodies against primary isolates of different genetic subtypes. Recently, we demonstrated that priming with DNA vaccines expressing primary HIV-1 envelope glycoprotein (Env) followed by recombinant Env protein boosting was successful in generating positive neutralizing antibody responses against a clade B primary HIV-1 isolate, JR-FL, that was not easily neutralized. In the current study, we examined whether the DNA priming plus recombinant protein boosting approach delivering a polyvalent primary Env formulation was able to generate neutralizing antibodies against primary HIV-1 viral isolates from various genetic subtypes. New Zealand White rabbits were first immunized with DNA vaccines expressing one, three or eight primary HIV-1 gp120 antigens delivered by a gene gun followed by recombinant gp120 protein boosting. Neutralizing antibody responses were examined by two independently executed neutralization assays: the first one was a single round infection neutralization assay against a panel of 10 primary HIV-1 isolates of subtypes A, B, C and E and the second one used the PhenoSense assay against a panel of 12 pseudovirues expressing primary HIV-1 Env antigens from subtypes A, B, C, D and E as well as 2 pseudoviruses expressing the Env antigens from MN and NL4-3 viruses. Rabbit sera immunized with the DNA priming plus protein boosting approach, but not DNA vaccine alone or Env protein alone, were capable of neutralizing 7 of 10 viruses in the first assay and 12 of 14 viruses in the second assay. More importantly, sera immunized with the polyvalent Env antigens were able to neutralize a significantly higher percentage of viruses than the sera immunized with the monovalent antigens. Our results suggest that DNA priming followed by recombinant Env protein boosting can be used to deliver polyvalent Env-antigen-based HIV-1 vaccines to elicit neutralizing antibody responses against viruses with diverse genetic sequence variations.

Strategies are needed for human immunodeficiency virus type 1 vaccine development that improves the neutralizing antibody response against primary isolates of the virus. Here we examined recombinant DNA priming followed by subunit protein boosting as a strategy to generate neutralizing antibodies. Both plasmidbased and recombinant protein envelope (Env) glycoprotein immunogens were derived from a primary viral isolate, JR-FL. Serum from rabbits immunized with either gp120 or gp140 DNA vaccines delivered by gene gun inoculation followed by recombinant gp120 protein boosting was capable of neutralizing JR-FL. Neither the DNA vaccines alone nor the gp120 protein alone generated a detectable neutralizing antibody response against this virus. Neutralizing antibody responses using gp120 DNA and gp140 DNA for priming were similar. The results suggest that Env DNA priming followed by gp120 protein boosting provides an advantage over either approach alone for generating a detectable neutralizing antibody response against primary isolates that are not easily neutralized.Neutralizing antibodies are considered critical immune components for effective vaccination against human immunodeficiency virus type 1 (HIV-1) infection and disease (5,10,16,19). The HIV-1 envelope glycoproteins (Env) are the primary viral antigens targeted by neutralizing antibodies. However, efforts to develop an Env-based immunogen that elicits an effective neutralizing antibody response are hampered by the high mutation rate of the virus in infected individuals (23) and the resulting genetic heterogeneity and structural complexity exhibited by Env (24). Thus, an effective HIV-1 vaccine will need to target a plethora of genetic and antigenic variants of the virus.A variety of candidate HIV-1 vaccines have included Env for the purpose of generating a neutralizing antibody response (8,14,20). Among these, DNA vaccines have proven to be poor inducers of neutralizing antibodies on their own but nonetheless prime for a detectable neutralizing antibody response after Env protein boosting (1,9,11,13,21,22). Unfortunately, the neutralizing antibodies generated in these studies have primarily targeted T-cell-line-adapted strains and a small fraction of primary isolates of HIV-1 that are unusually sensitive to neutralization. Most primary isolates of HIV-1 are substantially less sensitive to neutralization and more difficult to target with vaccines (2-4, 15).It has not been clear whether the DNA prime and protein boost strategy affords an advantage over Env protein immunization alone with respect to the elicitation of a neutralizing antibody response that targets typical primary HIV-1 isolates that are not easily neutralized. In this regard, the JR-FL strain of HIV-1 exhibits such a neutralization phenotype (6) and therefore represents a relevant viral target upon which different vaccine strategies can be evaluated and compared. In the present study, we investigated the ability of the JR-FL gp120 protein to generate a neutralizing antibody response with and with...

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BackgroundLangerhans cell histiocytosis (LCH) is a proliferative disease of histiocyte-like cells that generally affects children. Immunohistochemistry is essential to obtain the correct diagnosis, and treatment protocols are controversial.ObjectiveLangerhans cell histiocytosis (LCH) is easy to be misdiagnosed because of its various clinic features and laboratory results. This research focused on the clinicopathological, histopathological, immunohistochemical and other features of LCH and aimed to analyze LCH clinical features for improving diagnosis and decreasing misdiagnosis rate.Case reportA case of rare adult LCH was reported and the clinicopathological features were summarized by literature review. The multifocal form of this case includes diabetes insipidus, exophthalmos and mucocutaneous lesions in axillae and anogenital regions, such as infiltrated nodules, extensive coalescing, scaling, crusted papules and ulcerated plaques. The Langerhans cells diffusely infiltrated in the dermis and the tumor cells were positive for CD1a and S-100 expression. The diagnosis was Langerhans cell histiocytosis based on the pathological and immunohistochemical changes.ConclusionLCH has high rate of misdiagnosis and definitive diagnosis depends on pathological biopsy and X-ray examination. The prognosis is related to the onset age and the quantity of affected organs. Although specific therapeutic approach hasn't been well established, combined chemotherapy for multisystem lesions and surgical operation or radiotherapy for unifocal lesions may improve the therapy.

The immunogenicity of a poylvalent HIV-1 vaccine comprised of Env antigens from primary R5 isolates was evaluated in rhesus macaques. DNA vaccines encoding four Env antigens from multiple HIV-1 subtypes and HIV-1 Gag antigen from a single subtype elicited a persistent level of binding antibodies to gp120 from multiple HIV-1 isolates that were markedly enhanced following boosting with homologous gp120 proteins in QS-21 adjuvant irrespective of the route of DNA immunization. These sera neutralized homologous and, to a lesser degree, heterologous HIV-1 isolates. Four of the six immunized animals were completely protected following rectal challenge with a SHIV encoding Env from HIV-1(Ba-L), whereas the virus load was reduced in the remaining animals compared to naïve controls. Hence priming with DNA encoding Env antigens from multiple HIV-1 clades followed by boosting with homologous Env proteins elicits anti-HIV-1 immune responses capable of protecting macaques against mucosal transmission of R5 tropic SHIV isolate.

We present our recommended methods for conducting experiments with the mouse laser-induced CNV model to enhance reproducibility and minimize investigator bias.