Transmission dynamics and molecular characterization of HIV-1 epidemic among therapeutic failure patients in Santa Catarina state, southern Brazil

The HIV-1 epidemic in southern Brazil is mostly caused by subtype C, which contrasts the dominance of subtype B in the other regions of the country. Santa Catarina (SC), although the smallest state in the southern region, presents one of the highest incidences and mortality rates in Brazil due to AIDS. This work investigated the HIV-1 molecular diversity and phylogenetic transmission networks in SC state by analyzing a database of 3070 sequences of the national genotyping service. HIV-1C proved to be the most frequent subtype, with a significant increase in prevalence over time. HIV-1B was observed to be associated with highly educated men, suggesting a compartmentalization from other subtypes. Such observation was confirmed by the high frequency of HIV-1B circulating in MSM transmission networks. Identified transmission clusters were majority composed by individuals living up to 25 km away and interstate linkages were mainly between southern neighbor states. In general, individuals between 25 and 40 years old and sequences sampled after 2014 were more likely to be in transmission chains, in agreement with the universal treatment protocol launched in 2014. The present study brings new insights about HIV-1 transmission dynamics in southern Brazil.

The impact of in utero HIV exposure on gut microbiota, inflammation, and microbial translocation

HIV-exposed but uninfected (HEU) children represent a growing population and show a significantly higher number of infectious diseases, several immune alterations, compromised growth, and increased mortality rates when compared to HIV-unexposed children. Considering the impact that the gut microbiota has on general host homeostasis and immune system development and modulation, we hypothesized that HEU children present altered gut microbiota that is linked to the increased morbidity and the immune system disorders faced by them. Our experiments revealed no differences in beta and alpha diversity of the gut microbiota between HEU and unexposed children or between HIV-infected and uninfected mothers. However, there were differences in the abundance of several taxa from the gut microbiota between HEU and unexposed children and between HIV-infected and uninfected mothers. Functional prediction based on 16S rRNA sequences also indicated differences between HEU and unexposed children and between infected and uninfected mothers. In addition, we detected no differences between HEU and unexposed children in relation to weight, weight-for-age z scores, albumin serum levels, or microbial translocation and inflammation markers. In summary, HIV-infected mothers and their HIV-exposed children present alterations in the abundance of several taxa in the gut microbiome and the predicted functional metagenome when compared to uninfected mothers and unexposed children. Knowledge about the gut microbiome of HEU children in different settings is essential in order to determine better treatments for this susceptible population.

Abundance and population structure of Plesionika narval (Fabricius, 1787) in the Northeastern Atlantic

Analysis of abundance and population structure of Plesionika narval was performed on data concerning 5,255 specimens obtained from 62 fishing sets carried out off the Madeira archipelago (Northeastern Atlantic) between 2004 and 2008 in a depth range from 101 to 350 m. Abundance ranged from 0.01 to 19.74 specimens-per-trap and significant differences were found between seasons, probably as a result of an increment of population in the spring during the recruitment season. The analysis of size distribution revealed that the carapace length (CL) ranged from 2.45 to 28.61 mm and that mean female size consistently exceeded that of males. Differences in mean CL were statistically significant between depth strata and seasons. Of the specimens sampled, 57.00% were males, 41.88% females and 1.42% undetermined. Sex ratio also differed significantly between seasons according to depth strata, consolidating the hypothesis of the existence of seasonal migrations related with the reproductive cycle of this species. Ovigerous females showed larger sizes and occurred all year around and remain in shallow waters in winter, summer and autumn and move to deeper waters in spring. The highest frequency of ovigerous females was recorded in summer, between 151 and 200 m deep supporting the hypothesis that spawning of this species occurs in shallow waters, especially in late summer.

Weight-length relationships of six shrimp species caught off the Madeira Archipelago, Northeastern Atlantic

Length and weight relationships and descriptive statistics are reported for six shrimp species caught off the Madeira archipelago between 1983 and 2014 using bottom and floating traps from depths ranging from 50 to 1,300 m. The parameter b ranged between 2.36 for Plesionika ensis and 2.97 for Plesionika williamsi. All species showed a pattern of negative allometric growth. To the authors' knowledge all weight-length relationships presented herein are recorded for the first time from the Madeira area, and in the cases of Ligur ensiferus and Plesionika ensis are the first references worldwide.

Spatiotemporal and demographic history of the HIV-1 circulating recombinant form CRF31_BC in Brazil

CRF31_BC is an HIVs-1 recombinant form very prevalent in the southernmost capital city of Brazil, Porto Alegre. Recent studies have been describing a growing number of cases of infection by CRF31_BC in other Brazilian cities and countries, suggesting a process of expansion of this strain. Aiming to describe the city of origin, dispersion routes and demographic history of CRF31_BC, this study analyzed all HIV-1 CRF31_BC and Brazilian BC mosaic publicly available sequences. CRF31_BC classification was performed by bootscanning and tree reconstruction methods. Bayesian phylogeographic and phylodynamic model approaches were used to reconstruct the spatiotemporal and demographic history of 95 sequences identified as CRF31_BC-like. Porto Alegre was estimated to be the origin and center of the dispersion of the CRF31_BC for most of the analyzed locations. However, some viral transitions independent from Porto Alegre were observed in other cities from the Rio Grande do Sul state and also in other Brazilian states. The estimated CRF31_BC epidemic growth rate was similar to subtype C and B in Brazil. Our findings suggest that CRF31_BC, although mostly prevalent in south region, is circulating nation-wide with some localities presenting autochthonous transmissions.

Prospective study of the fishery of the shrimp Plesionika narval (Fabricius, 1787) in the Northeastern Atlantic

Several experimental surveys were carried out in the Northeastern Atlantic, Madeira archipelago from 1991 to 2008 to explore new fisheries resources. This study examined the selectivity of bottom and floating traps and the analysis of yield-per-recruit (YPR) and biomass-per-recruit (BPR) providing helpful insight to the management of the shrimp Plesionika narval. A total of 28,262 specimens were sampled and the analysis of length at first capture returned higher values when using floating traps indicating that these traps are more selective, exerting less pressure on the resource. The YPR and BPR analysis showed that the stock is under exploited for the studied area and suggests that the use of floating traps in the commercial fisheries of P. narval is recommended, which will allow a higher maximum allowable limit of exploitation and greater yield. The results suggest that P. narval has the potential to support a viable and sustainable fishery using floating traps.

Analysis of Immunological, Viral, Genetic, and Environmental Factors That Might Be Associated with Decreased Susceptibility to HIV Infection in Serodiscordant Couples in Florianópolis, Southern Brazil

Individuals who have been exposed to human immunodeficiency virus (HIV) and have not been infected might possess natural resistance mechanisms. An understanding of the sociodemographic and immunological conditions that influence resistance to HIV is a challenge, and very little is known about the role of intrinsic antiviral factors that restrict HIV infection. The aim of this study was to analyze potential factors responsible for resistance to HIV infection in serodiscordant couples by comparing HIV-exposed seronegative individuals (HESN) to HIV-seropositive individuals treated with antiretroviral therapy (HIV-ART) along with healthy controls (HC). The results revealed one HLA-B*27 and two HLA-B*57 individuals among the HESN; a CCR5Δ32 heterozygous deletion was observed in one serodiscordant couple, while the homozygous genotype for this variant was not observed. There were no differences in the basal mRNA expression of APOBEC3G, CFLAR, TRIM5α, LEDGF/p75, BST-2, or SAMHD1 in CD4(+) T lymphocyte- and monocyte-enriched populations among the three groups, and lower HBD-3 concentrations were observed in saliva from HIV-ART compared to HESN and HC. The most prevalent HIV-1 subtype was C or C-containing recombinant forms. Six HIV-ART individuals and one HIV-ART individual were infected with the R5 HIV and X4 HIV strains, respectively. The ability to control infection or delay disease progression is probably defined by a balance between viral and host factors, and further evaluation should be performed in larger cohorts. Our data suggest that susceptibility to HIV infection varies among individuals and strengthens the multifactorial characteristics underlying the resistance mechanisms in HIV.

HIV infection and antiretroviral therapy lead to unfolded protein response activation

Background

The unfolded protein response (UPR) is one of the pathways triggered to ensure quality control of the proteins assembled in the endoplasmic reticulum (ER) when cell homeostasis is compromised. This mechanism is primarily composed of three transmembrane proteins serving as stress sensors: PKR-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1). These three proteins’ synergic action elicits translation and transcriptional downstream pathways, leading to less protein production and activating genes that encode important proteins in folding processes, including chaperones. Previous reports showed that viruses have evolved mechanisms to curtail or customize this UPR signaling for their own benefit. However, HIV infection’s effect on the UPR has scarcely been investigated.

Methods

This work investigated UPR modulation by HIV infection by assessing UPR-related protein expression under in vitro and in vivo conditions via Western blotting. Antiretroviral (ARV) drugs’ influence on this stress response was also considered.

Results

In in vitro and in vivo analyses, our results confirm that HIV infection activates stress-response components and that ARV therapy contributes to changes in the UPR’s activation profile.

Conclusions

This is the first report showing UPR-related protein expression in HIV target cells derived directly from HIV-infected patients receiving different ARV therapies. Thus, two mechanisms may occur simultaneously: interference by HIV itself and the ARV drugs’ pharmacological effects as UPR activators. New evidence of how HIV modulates the UPR to enhance its own replication and secure infection success is also presented.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-015-0298-0) contains supplementary material, which is available to authorized users.

Application of green zero-valent iron nanoparticles to the remediation of soils contaminated with ibuprofen

Zero-valent iron nanoparticles (nZVIs) are often used in environmental remediation. Their high surface area that is associated with their high reactivity makes them an excellent agent capable of transforming/degrading contaminants in soils and waters. Due to the recent development of green methods for the production of nZVIs, the use of this material became even more attractive. However, the knowledge of its capacity to degrade distinct types of contaminants is still scarce. The present work describes the study of the application of green nZVIs to the remediation of soils contaminated with a common anti-inflammatory drug, ibuprofen. The main objectives of this work were to produce nZVIs using extracts of grape marc, black tea and vine leaves, to verify the degradation of ibuprofen in aqueous solutions by the nZVIs, to study the remediation process of a sandy soil contaminated with ibuprofen using the nZVIs, and to compare the experiments with other common chemical oxidants. The produced nZVIs had nanometric sizes and were able to degrade ibuprofen (54 to 66% of the initial amount) in aqueous solutions. Similar remediation efficiencies were obtained in sandy soils. In this case the remediation could be enhanced (achieving degradation efficiencies above 95%) through the complementation of the process with a catalyzed nZVI Fenton-like reaction. These results indicate that this remediation technology represents a good alternative to traditional and more aggressive technologies.

The increasing prevalence of HIV-1 subtype C in Southern Brazil and its dispersion through the continent

The HIV-1 has evolved swiftly and the scenario of HIV-1 genetic diversity is constantly changing. In South America, recombinant forms of subtypes B, F1, and BF1 have historically driven the HIV-1 epidemic. In recent years, however, infection with subtype C has gained prominence as its prevalence increased in Southern Brazil as well as neighboring countries. Current studies point to a single introduction of closely related strains as the beginning of the Brazilian subtype C epidemic. However, the place of origin of these strains, date, and route of introduction are under continuous debate as well as the clinical outcomes of the emergence of subtype C. Therefore, this paper reviews the history of the HIV-1 subtype C in Brazil, particularly in the Southern region, covering its demographic and evolutionary history and the possible implications to the Brazilian AIDS epidemic as well as to neighboring countries.

Challenges in shrimp aquaculture due to viral diseases: distribution and biology of the five major penaeid viruses and interventions to avoid viral incidence and dispersion

Shrimp aquaculture has been dramatically affected by many pathogenic diseases, mainly caused by five viruses: IHHNV, YHV, TSV, WSSV, and IMNV. Here we provide a state-of-the-art overview of these shrimp viruses, with emphasis on distribution, pathology, morphology, and genomic organization, in addition to current diagnostic methods and intervention practices.

Immunophenotyping of classic murine myeloma cell lines used for monoclonal antibody production

Murine myeloma cell lines play an important role in different areas of scientific research and are essential tools for monoclonal antibody production technology. Thus, it is important to understand the biology of these cell lines in order to provide useful information to various research fronts. The present study aims to perform detailed analyses of surface antigens expressed on three major murine myeloma cell lines extensively used for MAb production. The P3X63Ag8.653 cell line expresses molecules associated with T cell interaction (CD40(low), CD80(low)), as well as antigens related to plasma cell phenotype (CD138(high), CD184(low)). The Sp2/0-Ag14 cell line presents molecules associated with BCR activation and regulation (CD79b(low), CD22(low), CD72(med)), molecules related to T cell interaction (CD40(low), CD80(low)), and markers of plasma cell phenotype (CD138(high), CD184(low)). The NS1 cell line presents all molecules of plasma cell phenotype evaluated in this study (CD184(low), CD138(high), CD38(med)) with low expression of CD72 (CD72(low)), a molecule related to BCR activation. Molecules associated with immune response modulation such as CD23 and CD25, as well as CD117, a marker related to undifferentiated cell phenotype, were not observed in any of the three murine myeloma cell lines evaluated. These data show that in spite of their common origin and function, the immunological profiles differ between P3X63Ag8.653, Sp2/0-Ag14, and NS1 cell lines.

Case report of a haemovigilance investigation using phylogenetic analysis of HIV-1 in Brazil

OBJECTIVES

The aim of this work is to provide the first report of a transfusion-acquired HIV-1 infection and to verify transmission from the donor to the recipients using phylogenetic analysis of HIV-1 DNA sequences in a Brazilian blood bank.

BACKGROUND

Although haemovigilance procedures based on phylogenetic analysis of HIV have been reported in several countries, this type of study has yet to be conducted in Latin America.

MATERIALS AND METHODS

Upon identifying a HIV-1-positive repeat blood donor by enzyme immunoassay (EIA) blood screening, all recipients of the donor's previous donation were identified and tested for HIV-1 by EIA, nucleic acid amplification test and HIV-1 DNA sequencing and phylogenetic analysis.

RESULTS

One of the recipients tested positive for HIV-1. The phylogenetic analysis showed a high genetic similarity among the viruses, thus supporting the hypothesis of transmission from the donor to the recipient.

CONCLUSIONS

Phylogenetic analysis of HIV-1 DNA sequences has been a decisive tool in verifying suspected transmission of the virus from blood donor to recipient in Brazil.

HIV-1 genetic diversity and drug resistance among treatment naïve patients from Southern Brazil: an association of HIV-1 subtypes with exposure categories

BACKGROUND

The AIDS epidemic in Southern Brazil has unique features, showing co-circulation of HIV-1 subtypes C, B and recombinant forms. Florianópolis has the second highest AIDS incidence among Brazilian capitals, but limited information is available about HIV molecular epidemiology and prevalence of primary drug resistance.

OBJECTIVES

To investigate the molecular epidemiology of HIV-1 in Florianópolis and to describe the prevalence of primary HIV-1 drug resistance mutations (DMRs).

STUDY DESIGN

Epidemiological and clinical data from 82 untreated patients from Florianópolis (2008-2009) were analyzed. The HIV-1 subtype at envelope, protease, reverse transcriptase and integrase regions were determined by phylogenetic and bootscaning analyses and the drug resistance profile were analyzed at the Stanford HIV Drug Resistance Database.

RESULTS

The most frequent HIV-1 genetic form was subtype C (65.8%) followed by mosaics BC (18.3%), subtype B (13.4%), subtype F1 (1.2%) and BCF1 recombinant (1.2%). HIV-1 subtype C and BC recombinants were much more frequent in the heterosexual exposure category, whereas subtype B was more common in the MSM exposure category. DRMs were seen in 11% of the sequences, 2.4% of them were related to PI, 5% to NRTI, 3.6% to NNRTI and 1.2% was related to INTI.

CONCLUSIONS

The present study confirms the high prevalence of subtype C and BC recombinants in Santa Catarina State and revealed a significant difference in the subtype distribution among distinct virus exposure categories. This study also shows a relative high prevalence of protease/reverse transcriptase primary drug resistance mutations and corroborates the usefulness of the integrase inhibitors in southern Brazil.

Robust genital gag-specific CD8+ T-cell responses in mice upon intramuscular immunization with simian adenoviral vectors expressing HIV-1-gag

Most studies on E1-deleted adenovirus (Ad) vectors as vaccine carriers for antigens of HIV-1 have focused on induction of central immune responses, although stimulation of mucosal immunity at the genital tract (GT), the primary port of entry of HIV-1, would also be highly desirable. In this study, different immunization protocols using chimpanzee-derived adenoviral (AdC) vectors expressing Gag of HIV-1 clade B given in heterologous prime-boost regimens were tested for induction of systemic and genital immune responses. Although i.n. immunization stimulated CD8(+) T-cell responses that could be detected in the GT, this route induced only marginal cellular responses in systemic tissues and furthermore numbers of Gag-specific CD8(+) T cells contracted sharply within a few weeks. On the contrary, i.m. immunization induced higher and more sustained frequencies of vaccine-induced cells which could be detected in the GT as well as systemic compartments. Antigen-specific CD8(+) T cells could be detected 1 year after immunization in all compartments analyzed. Genital memory cells secreted IFN-γ, expressed high levels of CD103 and their phenotypes were consistent with a state of activation. Taken together, the results presented here show that i.m. vaccination with chimpanzee-derived (simian) adenovirus vectors is a suitable strategy to induce a long-lived genital CD8(+) T-cell response.

Detection of major capsid protein of infectious myonecrosis virus in shrimps using monoclonal antibodies

Infectious myonecrosis virus (IMNV) has been causing a progressive disease in farm-reared shrimps in Brazil and Indonesia. Immunodiagnostic methods for IMNV detection, although reliable, are not employed currently because monoclonal antibodies (MAbs) against this virus are not available. In this study, a fragment of the IMNV major capsid protein gene, comprising amino acids 300-527 (IMNV(300-527)), was cloned and expressed in Escherichia coli. The nucleotide sequence of the recombinant IMNV(300-527) fragment displayed a high degree of identity to the major capsid protein of IMNV isolates from Brazil (99%) and Indonesia (98%). Ten MAbs were generated against the expressed fragment, and eight of these, mostly IgG(2a) or IgG(2b), were able to bind to IMNV in tissue extracts from shrimps infected naturally in immunodot-blot assays. Six of these MAbs recognized a approximately 100 kDa protein in a Western-blot, which is the predicted mass of IMNV major capsid protein, and also bound to viral inclusions present in muscle fibroses and in coagulative myonecrosis, as demonstrated by immunohistochemistry. Among all those MAbs created, four did not cross-react with non-infected shrimp tissues; this observation supports their applicability as a sensitive and specific immunodiagnosis of IMNV infection in shrimps.

Simian recombinant adenovirus delivered by the mucosal route modulates gammadelta T cells from murine genital tract

Although it has been demonstrated that mucosal immunization using vectors such as simian adenovirus (AdC) stimulates robust adaptive immune responses, there remains a paucity of information on the modulation of innate immune responses by such vectors. Using an established murine model of intravaginal immunization (Ivag), we have investigated whether mucosal gammadelta T cells participate in immune responses induced by AdC vectors. gammadelta T cell numbers were found to be increased in the vaginal tract. Moreover, gammadelta T cells isolated from the genital tract showed an activated phenotype and enhanced expression of cytokine gene. Altogether, our results demonstrate that AdC modulates gammadelta T cell responses and suggest that this cell population may influence immune responses following vaginal immunization.

A novel monoclonal antibody that binds to hemocytes from shrimps and oysters

The monoclonal antibody (MAb) LITO-1 was produced from a stable hybridoma cell line generated by the fusion of NS1 myeloma cells with spleen cells isolated from Balb/c mice immunized with a paraformaldehyde-fixed hemocyte suspension of Litopenaeus vannamei. This MAb reacted with all three hemocyte subtypes, but no reaction was observed with components of plasma. Immunohistochemistry assays demonstrated that LITO-1 was very effective in specifically distinguishing hemocytes infiltrated in several tissues such as striated muscle, brain, and hepatopancreas. Moreover, this antibody was able to recognize hemocytes from two shrimp species, Litopenaeus schmitti and Farfantepenaeus paulensis, as well as hemocytes of the oyster Crassostrea gigas. No reaction was observed against hemocytes from the terrestrial insect Triatoma klugi or with mammalian RAW cells. This novel MAb can be useful in revealing the presence and function of a conservative epitope in hemocytes of marine crustaceans and mollusks.

An optimized nested polymerase chain reaction (PCR) approach allows detection and characterization of human immunodeficiency virus type 1 (HIV-1) env and gag genes from clinical samples

The needs for development and/or improvement of molecular approaches for microorganism detection and characterization such as polymerase chain reaction (PCR) are of high interest due their sensitivity and specificity when compared to traditional microbiological techniques. Considering the worldwide importance of human immunodeficiency virus type 1 (HIV-1) infection, it is essential that such approaches consider the genetic variability of the virus, the heterogeneous nature of the clinical samples, the existence of contaminants and inhibitors, and the consequent needs for standardization in order to guarantee the reproducibility of the methods. In this work we describe a nested PCR assay targeting HIV-1 virus gag and env genes, allowing specific and sensitive diagnosis and further direct characterization of clinical samples. The method described herein was tested on clinical samples and allowed the detection of HIV-1 presence in all samples tested for the gag gene and 90.9% for the env gene, revealing sensitivities of 1 fg and 100 fg, respectively. Also, no cross-reactions were observed with DNA from infected and noninfected patients and the method allowed detection of the env and gag genes on an excess of 10(8) and 10(4) of human deoxyribonucleic acid (DNA), respectively. Furthermore, it was possible to direct sequence all amplified products, which allowed the sub typing of the virus in clinical samples.

Molecular epidemiology of HIV-1 in Santa Catarina State confirms increases of subtype C in Southern Brazil

Recent studies have demonstrated an increased prevalence of human immunodeficiency virus type 1 (HIV-1) subtype C in southern Brazil. Although Santa Catarina State (SC) is located in this area and presents one of the country's highest incidences of HIV/AIDS, knowledge on the molecular epidemiology of HIV-1 in such State is lacking. The aim of this study was to investigate the HIV-1 molecular diversity and epidemiological profile of HIV-1-infected patients from SC. DNA samples were PCR amplified and HIV-1 subtypes were determined using both env and gag genes by direct sequencing. Phylogenetic analyses revealed that 48% were subtype C and 23% were subtype B. Possible recombinant forms were observed for both B/C (23%) and B/F (6%) subtypes. Our results, for the first time, identifies HIV-1 subtype C as a major clade circulating in SC and contributes to the understanding of HIV epidemics in the country by confirming the epidemic spread of the HIV-1 subtype C in southern Brazil.

Genital CD8+ T cell response to HIV-1 gag in mice immunized by mucosal routes with a recombinant simian adenovirus

AdC6gag37, an E1-deleted adenovirus recombinant derived from the chimpanzee adenovirus serotype 6 expressing a codon-optimized truncated form of gag of HIV-1, was tested for induction of transgene-specific CD8+ T cell responses upon intranasal or intravaginal immunization of mice. Administration of AdC6gag37 induced gag-specific CD8+ T cells at systemic and mucosal sites. Frequencies of gag-specific CD8+ T cells elicited in the genital tract by intravaginal or intranasal immunizations were substantially increased by intranasal priming followed by intravaginal boosting with the same vector. Additionally, intravaginal immunization with AdC6gag37 increased the amount of gammadelta T cells that could be detected in genital tract.

Shear stress, temperature, and inoculation concentration influence the adhesion of water-stressed Helicobacter pylori to stainless steel 304 and polypropylene

Although molecular techniques have identified Helicobacter pylori in drinking water-associated biofilms, there is a lack of studies reporting what factors affect the attachment of the bacterium to plumbing materials. Therefore, the adhesion of H. pylori suspended in distilled water to stainless steel 304 (SS304) coupons placed on tissue culture plates subjected to different environmental conditions was monitored. The extent of adhesion was evaluated for different water exposure times, using epifluorescence microscopy to count total cell numbers. High shear stresses-estimated through computational fluid dynamics-negatively influenced the adhesion of H. pylori to the substrata (P < 0.001), a result that was confirmed in similar experiments with polypropylene (P < 0.05). However, the temperature and inoculation concentration appeared to have no effect on adhesion (P > 0.05). After 2 hours, H. pylori cells appeared to be isolated on the surface of SS304 and were able to form small aggregates with longer exposure times. However, the formation of a three-dimensional structure was only very rarely observed. This study suggests that the detection of the pathogen in well water described by other authors can be related to the increased ability of H. pylori to integrate into biofilms under conditions of low shear stress. It will also allow a more rational selection of locations to perform molecular or plate culture analysis for the detection of H. pylori in drinking water-associated biofilms.

Evaluation of antiviral activity of phenolic compounds and derivatives against rabies virus

Human rabies is a viral disease with a great impact on public health, mainly on account of its fatal course in the majority of cases. Despite the well-established prophylaxis by immunization, rabies is believed to be responsible for 40,000-70,000 human deaths per year, mostly in endemic areas. Palliative support and experimental protocols to avoid death have been employed with no expressive results, with the exception of a recent human case of recovery from rabies. No antiviral drugs are currently available to fight against this infection. In combination with the prophylaxis, an antiviral drug would be useful for human rabies treatment, providing enhanced protection against the encephalitis caused by the virus. Phenolic compounds are derived from the secondary plant metabolism, although they can also be obtained by synthetic processes. Many studies have shown a great range of pharmacological effects for these substances, including vasodilatation, antiallergenic, antiinflammatory and antiviral properties, among others. In this study, the potential in-vitro anti-rabies activity of 24 synthetic phenolic compounds was evaluated using McCoy cells and PV rabies strain. The cytotoxicity (CC50) was assayed by the MTT method and the antiviral activity (IC50) was estimated by the inhibition of viral cytopathic effects. Isoprinosine and ketamine were used as positive controls. The tested compounds showed selectivity indices (SI=CC50/IC50) ranging from 1.0 to 3.9. Six phenolic compounds failed to inhibit the cytopathic effect to any degree, and four showed SI > or = 3.0. According to these results, some probable structure-activity relationships are suggested. It was observed that the presence of free hydroxyl and ether groups influenced the anti-rabies activity. However, additional studies are required to establish these relationships.

Recombinant viruses as vaccines against viral diseases

Vaccine approaches to infectious diseases are widely applied and appreciated. Amongst them, vectors based on recombinant viruses have shown great promise and play an important role in the development of new vaccines. Many viruses have been investigated for their ability to express proteins from foreign pathogens and induce specific immunological responses against these antigens in vivo. Generally, gene-based vaccines can stimulate potent humoral and cellular immune responses and viral vectors might be an effective strategy for both the delivery of antigen-encoding genes and the facilitation and enhancement of antigen presentation. In order to be utilized as a vaccine carrier, the ideal viral vector should be safe and enable efficient presentation of required pathogen-specific antigens to the immune system. It should also exhibit low intrinsic immunogenicity to allow for its re-administration in order to boost relevant specific immune responses. Furthermore, the vector system must meet criteria that enable its production on a large-scale basis. Several viral vaccine vectors have thus emerged to date, all of them having relative advantages and limits depending on the proposed application, and thus far none of them have proven to be ideal vaccine carriers. In this review we describe the potential, as well as some of the foreseeable obstacles associated with viral vaccine vectors and their use in preventive medicine.

Induction of CD8+ T cells to an HIV-1 antigen upon oral immunization of mice with a simian E1-deleted adenoviral vector

An E1-deleted adenoviral recombinant derived from the chimpanzee serotype 6 expressing a codon-optimized truncated form of gag of human immunodeficiency virus type 1 (HIV-1) was tested for induction of a transgene product-specific CD8+ T cell response upon oral immunization of mice. The vector was shown to induce gag-specific CD8+ T cells detectable at moderate frequencies of approximately 0.5-1.0% in the spleens and to provide partial protection in a surrogate challenge model based on intraperitoneal (i.p.) infection of mice with a vaccinia virus recombinant expressing gag (VVgag) of HIV-1. Frequencies of gag-specific CD8+ T cells could be augmented by using a different, i.e., heterologous, vaccine carrier based on a distinct recombinant virus or an alternative adenoviral serotype expressing the same form of gag for oral or systemic-booster immunization.

Chemokines and TRANCE as genetic adjuvants for a DNA vaccine to rabies virus

An adaptive immune response is initiated by mature dendritic cells presenting processed antigen to nai;ve T cells. Assuming that the magnitude of the immune response is influenced by the number and type of antigen-presenting dendritic cells and by the duration of antigen presentation, we tested if chemokines that bind to receptors expressed on immature dendritic cells or TRANCE, a survival factor for mature dendritic cells, can serve as adjuvants. None of the immunomodulaters given as genetic adjuvants with a DNA vaccine encoding the full-length rabies virus glycoprotein augmented the transgene product-specific response. However, RANTES, MCP-1, MIP 1-beta, and TRANCE given together with a DNA vaccine expressing a truncated and thus secreted version of the rabies virus glycoprotein enhanced the response suggesting that the tested genetic adjuvants promoted preferentially presentation of reprocessed antigen originating from transduced tissue cells.

DNA-based vaccination against murine paracoccidioidomycosis using the gp43 gene from paracoccidioides brasiliensis

Gp43, the major 43-kDa antigenic glycoprotein of Paracoccidioides brasiliensis, or its 15-amino acid inner peptide (P10), induces a T-CD4(+), Th1 cellular immune response which protects BALB/c mice from intratracheal infection by virulent yeast forms. We investigated whether DNA vaccination using the gp43 gene could elicit protective immunity against P. brasiliensis. Animals immunised intramuscularly (i.m.) or intradermally (i.d.) with plasmid DNA containing the gp43 gene induced a specific, long lasting humoral and cellular immune response. A mixed Th1/Th2 cellular immune response in DNA-immunized mice was modulated in vivo by IFN-gamma and was protective in BALB/c mice. A significant decrease in the lung colony forming units (CFUs) and reduced, or no dissemination to the spleen and liver of immunised mice were observed.

Identification of a 30 kDa antigen from leishmania (L.) chagasi amastigotes implicated in protective cellular reponses in a murine model

An antigen of apparent molecular mass of 30 kDa, termed p30, was purified from Leishmania (L.) chagasi amastigotes after separation of parasite extracts by sodium dodecyl sulfate-polyacrylamide gel eletroctrophoresis followed by electroelution. The use of the purified antigen in lymphocyte cultures from BALB/c mice previously immunised with L. (L.) chagasi amastigotes led to high levels of proliferation. Animal immunisation with p30 plus complete Freund's adjuvant either by subcutaneous or intraperitoneal route led to comparable antigenic stimulation. Similar stimulation indices induced by p30 were also obtained when animals were immunised with Corynebacterium parvum as adjuvant by the intraperitoneal route. Detection of IL-2 and IFN-gamma in the supernatants from lymphocytes stimulated by p30 and inhibition of the production of these lymphokines in the presence of anti-CD4 strongly indicated the involvement of the Th1 subset in the responses elicited by p30 antigen. Immunisation of BALB/c mice with p30 provided partial protection against challenge with L. (L.) chagasi amastigotes, indicating a protective role for p30 and that Th1 can be related to accquired resistance to visceral leishmaniasis in a murine model. Further characterisation studies were performed by the use of a monoclonal antibody directed to a cysteine proteinase of 30 kDa from L. (L.) amazonensis amastigotes. Despite the cross-reactivity presented by p30 from both Leishmania species, the p30 from L. (L.) chagasi amastigotes lacks proteolytic activity.

Characterization of an antigen from Leishmania amazonensis amastigotes able to elicit protective responses in a murine model

Lymphoproliferative responses to an antigen from Leishmania amazonensis amastigotes with an apparent molecular mass of 30 kDa, termed p30, were evaluated with BALB/c mice. The p30 antigen was purified after separation of parasite extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by electroelution. Lymphoproliferative responses to p30 were obtained by subcutaneous immunization of animals with L. amazonensis amastigote extracts, and maximal stimulation indices were observed at an antigen concentration of 5 microg/ml. Induction of lymphoproliferation by p30 is stage specific, and no differences in the responses to this antigen between mice susceptible and resistant to L. amazonensis were detected. The predominant T cells characterized in the lymphocyte cultures were CD4+. Lymphokine analysis of the supernatants from these cultures indicated that Th1 is the subset involved in the lymphoproliferative responses to the antigen. BALB/c mice immunized with p30 and challenged with L. amazonensis amastigotes showed a very low level of infection, indicating a protective role for p30 and a correlation between Th1 and protection. Further biochemical characterization studies showed that this antigen presents cysteine proteinase activity.

Systemic nodular panniculitis in a patient with alpha-1 antitrypsin deficiency (PiSS phenotype)

The association of alpha-1 antitrypsin deficiency (PiZ phenotype) with systemic nodular panniculitis has been well documented. Despite reports of cases of systemic nodular panniculitis associated with other alpha-1 antitrypsin deficiency phenotypes, it is still not known if this association is fortuitous rather than causal. We report a case of systemic nodular panniculitis associated with alpha-1 antitrypsin deficiency (PiSS phenotype), with clinico-pathological features similar to those reported in cases associated with the PiZ phenotype.

Fatal Aspergillus pneumonia in chronic granulomatous disease

A 20-year-old man died from Aspergillus pneumonia three weeks after heavy exposure to grain dust. Lung biopsy and autopsy demonstrated a distinctive form of suppurating granulomatous bronchopneumonia caused by Aspergillus fumigatus, which was the sole agent cultured from the tissue. The liver and lymph nodes contained pigmented lipid histiocytes characteristic of chronic granulomatous disease, and subsequently both of the patient's brothers were found to have X-linked chronic granulomatous disease. The authors suggest that this morphologic expression of Aspergillus pneumonia should raise a suspicion of neutrophil dysfunction or chronic granulomatous disease.