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The study purpose was to evaluate a computer-based questionnaire (SCKnowIQ) and CHOICES educational intervention using cognitive interviewing with childbearing-aged people with sickle cell disease (SCD) or trait (SCT). Ten control group participants completed the SCKnowIQ twice. Ten intervention group participants completed the SCKnowIQ before and after the CHOICES intervention. Most participants found the questionnaire items appropriate and responded to items as the investigators intended. Participants’ responses indicated that the information on SCD and SCT and reproductive options was understandable, balanced, important, and new to some. Internal consistency and test–retest reliability were adequate (.47 to .87) for 4 of the 6 scales, with significant within-group changes in knowledge scores for the intervention group but not for the control group. Findings show evidence for potential efficacy of the intervention, but proof of efficacy requires a larger randomized study.

CD8+ cells from simian immunodeficiency virus (SIV)-infected long-term non-progressors and some uninfected macaques can suppress viral replication in vitro without killing the infected cells. The aim of this study was to identify factors responsible for non-cytolytic viral suppression by transcriptional profiling and to investigate their potential impact on SIV replication. Results of microarray experiments and further validation with cells from infected and uninfected macaques revealed that FAM26F RNA levels distinguished CD8+ cells of controllers and non-controllers (P=0.001). However, FAM26F was also expressed in CD4+ T-cells and B-cells. FAM26F expression increased in lymphocytes after in vitro IFN-gamma treatment on average 40-fold, and ex vivo FAM26F RNA levels in peripheral blood mononuclear cells correlated with plasma IFN-gamma but not with IFN-alpha. Baseline FAM26F expression appeared to be stable for months, albeit the individual expression levels varied up to tenfold. Investigating its role in SIV-infection revealed that FAM26F was upregulated after infection (P

E. multilocularis (Em) is the etiologic agent of alveolar echinococcosis (AE), a severe and potentially fatal disease, primarily affecting the liver of and occurring in aberrant intermediate hosts, e.g., humans and non-human primates. Due to increasing numbers of spontaneous cases of AE in the Old World monkey colonies of the German Primate Center, the question arose as to whether vaccination of non-human primates may represent a useful prophylactic approach. In this pilot study, the recombinant antigen Em14-3-3, which has provided a 97 % protection against E. multilocularis challenge infection in rodent models, was used for the first time to immunize rhesus macaques. In order to increase immunogenicity, the antigen was formulated with different adjuvants including Quil A®, aluminum hydroxide (alum), and muramyl dipeptide (MDP). Also, different vaccination regimens were tested. All vaccinated animals developed antigen-specific antibodies. While Quil A® induced a local adverse reaction, alum proved to be the most potent adjuvant in terms of induced antibody levels, longevity as well as tolerability. In conclusion, our pilot study demonstrated that recombinant Em14-3-3 is safe and immunogenic in rhesus monkeys. As a next step, efficacy of the vaccination remains to be explored.

Granzyme B-expressing (GrB+) B cells are thought to contribute to immune dysfunctions in HIV patients, but so far their exact role is unknown. This report demonstrates for the first time the existence of GrB+ B cells in SIV-infected rhesus macaques, which represent the most commonly used nonhuman primate model for HIV research. Similar to HIV patients, we found significantly higher frequencies of these cells in the blood of chronically SIV-infected rhesus monkeys compared with uninfected healthy ones. These frequencies correlated with plasma viral load and inversely with absolute CD4 T-cell counts. When investigating GrB+ B cells in different compartments, levels were highest in blood, spleen and bone marrow, but considerably lower in lymph nodes and tonsils. Analysis of expression of various surface markers on this particular B-cell subset in SIV-infected macaques revealed differences between the phenotype in macaques and in humans. GrB+ B cells in SIV-infected rhesus macaques exhibit an elevated expression of CD5, CD10, CD25 and CD27, while expression of CD19, CD185 and HLA-DR is reduced. In contrast to human GrB+ B cells, we did not observe a significantly increased expression of CD43 and CD86. B-cell receptor stimulation in combination with IL-21 of purified B cells from healthy animals led to the induction of GrB expression. Furthermore, initial functional analyses indicated a regulatory role on T-cell proliferation. Overall, our data pave the way for longitudinal analyses including studies on the functionality of GrB+ B cells in the nonhuman primate model for AIDS.

Background Common marmosets are extensively used in immunological and pharmacological research, and the usage of methods such as flow cytometry gain increasing importance. Methods Using multicolor flow cytometry cross-reactivity of monoclonal antibodies with cells of common marmosets was analyzed. Furthermore, frequencies of immune cells and immunological parameters were assessed in healthy common marmosets. Results A total of 97 clones of monoclonal antibodies raised against CD markers, chemokine receptors, and miscellaneous markers were tested. Additionally, baseline frequencies of different innate and adaptive immune cells as well as certain parameters, such as activation and memory T-cell and B-cell distribution, are provided. Conclusion Our study gives an extended overview of cross-reactive antibodies for flow cytometric analysis of immune cells as well as baseline values for different immune parameters in healthy common marmosets.

CD4+ T cell repopulation of the gut is rarely achieved in HIV-1–infected individuals who are receiving clinically effective antiretroviral therapy. Alterations in the integrity of the mucosal barrier have been indicated as a cause for chronic immune activation and disease progression. In this study, we present evidence that persistent immune activation causes impairment of lymphocytes to respond to chemotactic stimuli, thus preventing their trafficking from the blood stream to peripheral organs. CCR6+ and CXCR3+ Th cells accumulate in the blood of aviremic HIV-1–infected patients on long-term antiretroviral therapy, and their frequency in the circulation positively correlates to levels of soluble CD14 in plasma, a marker of chronic immune activation. Th cells show an impaired response to chemotactic stimuli both in humans and in the pathogenic model of SIV infection, and this defect is due to hyperactivation of cofilin and inefficient actin polymerization. Taking advantage of a murine model of chronic immune activation, we demonstrate that cytoskeleton remodeling, induced by okadaic acid, restores lymphocyte migration in response to chemokines, both in vitro and in vivo. This study calls for novel pharmacological approaches in those pathological conditions characterized by persistent immune activation and loss of trafficking of T cell subsets to niches that sustain their maturation and activities.

Cervical cancer is the second most common cancer in women worldwide. Persistent high-risk human papillomavirus (HPV) infection has been identified as the causative event for the development of this type of cancer. Recombinant adeno-associated viruses (rAAVs) are currently being developed and evaluated as vaccine vector. In previous work, we demonstrated that rAAVs administered intranasally in mice induced high titers and long-lasting neutralizing antibodies against HPV type 16 (HPV16). To extend this approach to a more human-related species, we immunized rhesus macaques (Macaca mulatta) with AAVs expressing an HPV16 L1 protein using rAAV5 and 9 vectors in an intranasal prophylactic setting. An rAAV5-L1 vector followed by a boost with rAAV9-L1 induced higher titers of L1-specific serum antibodies than a single rAAV5-L1 immunization. L1-specific antibodies elicited by AAV9 vector neutralized HPV16 pseudovirions and persisted for at least 7 months post immunization. Interestingly, nasal application of rAAV9 was immunogenic even in the presence of high AAV9 antibody titers, allowing reimmunization with the same serotype without prevention of the transgene expression. Two of six animals did not respond to AAV-mediated intranasal vaccination, although they were not tolerant, as both developed antibodies after intramuscular vaccination with HPV16 virus-like particles. These data clearly show the efficacy of an intranasal immunization using rAAV9-L1 vectors without the need of an adjuvant. We conclude from our results that rAAV9 vector is a promising candidate for a noninvasive nasal vaccination strategy.

The availability of an effective vaginal microbicide would be a major step toward containment of HIV transmission as well as allowing women self-protection against HIV infection. Here we evaluated the efficacy of vaginal application of the potent nonnucleoside reverse transcriptase inhibitor (NNRTI) MC 1220 against vaginal challenge of macaques with RT-SHIV, a chimeric simian immunodeficiency virus (SIV) containing the reverse transcriptase (RT) gene of HIV-1. Challenge infection of monkeys with RT-SHIV currently represents the only nonhuman primate model available to test the anti-HIV-1 effects of NNRTIs. Two different gel formulations containing different MC 1220 concentrations were evaluated for efficacy in female rhesus macaques exposed to RT-SHIV. Five groups of five animals each were treated with two different gel compositions containing no drug, 0.1% or 0.5% MC 1220, followed by vaginal RT-SHIV challenge 30 min later. One animal in each group treated with the low concentration of MC 1220 as well as one control animal remained uninfected after vaginal challenge. By contrast, three of the animals receiving 0.5% MC 1220 remained uninfected, suggesting a threshold of the drug. Despite being negative for plasma viral RNA and absence of seroconversion, almost all uninfected animals exhibited SIV-specific T cells, either in the periphery or in lymph nodes draining the portal of virus entry. Our results make MC 1220 a promising compound for further development as a topical microbicide and warrant additional testing with improved formulation, long-lasting vaginal delivery systems, or even combinations with other inhibitors.

Objective: To determine the loss of CD4 + T cells and virus-specific cytotoxic T cells (CTL) in different mucosal sites of rhesus monkeys infected with simian immunodeficiency virus (SIV). Design: A cross-sectional comparative investigation of seven different mucosal sites from chronically SIV-infected rhesus monkeys was performed by analyzing blood and mucosal lymphocytes. Methods: Mucosal lymphocytes were isolated from duodenum, jejunum, ileum and colon as well as from vagina, cervix and uterus of SIV-infected rhesus monkeys at necropsy. CD4 + T cells and SIV-Gag-specific CTL were determined in blood and mucosal samples by flow cytometry. Results: A significant depletion of CD4 + T cells was observed in blood and all mucosal sites of SIV-infected rhesus monkeys compared to uninfected animals. But the mean percentage loss of CD4 + T cells varied between 66 and 95% between the different mucosal tissues. The frequency of CTL ranged between 0.4 and 2.4% with the highest proportions in vagina and cervix. Among the intestinal sites the mean levels of CTL correlated with mean percentage loss of CD4 + T cells. Conclusion: A discriminative pronounced loss of CD4 + T cells among the mucosal tissues confirmed that viral replication affects different mucosal sites in a distinct way. Despite high levels of CTL, especially in vagina and cervix, the severe loss of mucosal CD4 + T cells could not be prevented during chronic SIV infection. However, within the four sites of the intestine a high virus-specific cellular immune response correlated with better preservation of CD4 + T cells.

Background Rhesus monkeys play a central role in model studies on human infectious diseases, and often mucosal organs are affected by these pathogens, e.g. HIV. However, a comparative investigation into lymphocyte composition from different mucosal tissues is still missing. Methods Lymphocyte composition of duodenum, jejunum, ileum, colon, vagina, cervix, uterus and bronchoalveolar lavage from healthy rhesus monkeys was characterized in detail by flow cytometry. Moreover, we compared the lymphocyte proportions from intestinal biopsies with resections. Results All mucosal tissues exhibited higher values of CD8+, CD4+ CCR5+ and CD45RA− memory T cells than blood, but similar levels of total T cells. Especially within the four gut sites, the lymphocyte composition varied significantly. The relative proportions of lymphocyte subsets from duodenal and colonic biopsies compared to resections differed. Conclusion The lymphocyte composition highly varies between different mucosal sites, and data obtained from biopsy and necropsy samples were mostly not comparable.

Understanding the lack of disease progression in nonpathogenic simian immunodeficiency virus (SIV) infections is essential for deciphering the immunopathogenesis of human AIDS. Yet, in vivo studies have been hampered by a paucity of infectious molecular clones (IMCs) of SIV suitable to dissect the viral and host factors responsible for the nonpathogenic phenotype. Here, we describe the identification, cloning, and biological analysis of the first transmitted/founder (T/F) virus representing a nonpathogenic SIV infection. Blood was collected at peak viremia from an acutely infected sabaeus monkey ( Chlorocebus sabaeus ) inoculated intravenously with an African green monkey SIV (SIVagm) strain (Sab92018) that had never been propagated in vitro . To generate IMCs, we first used conventional (bulk) PCR to amplify full-length viral genomes from peripheral blood mononuclear cell (PBMC) DNA. Although this yielded two intact SIVagmSab genomes, biological characterization revealed that both were replication defective. We then performed single-genome amplification (SGA) to generate partially overlapping 5′ ( n = 10) and 3′ ( n = 13) half genomes from plasma viral RNA. Analysis of these amplicons revealed clusters of nearly identical viral sequences representing the progeny of T/F viruses. Synthesis of the consensus sequence of one of these generated an IMC (Sab92018ivTF) that produced infectious CCR5-tropic virions and replicated to high titers in Molt-4 clone 8 cells and African green monkey PBMCs. Sab92018ivTF also initiated productive infection in sabaeus monkeys and faithfully recapitulated the replication kinetics and nonpathogenic phenotype of the parental Sab92018 strain. These results thus extend the T/F virus concept to nonpathogenic SIV infections and provide an important new tool to define viral determinants of disease nonprogression.

Background Chronic immune activation is a hallmark of HIV infection and has been postulated as major factor in the pathogenesis of AIDS. Recent evidence suggests that activation of immune cells is triggered by microbial translocation through the impaired gastrointestinal barrier. Methods To determine the association between microbial translocation and disease progression, we have retrospectively analyzed microbial products, viral load and markers of immune activation in a cohort of 37 simian immunodeficiency virus-infected rhesus monkeys, divided in two groups with distinct disease courses. Results As seen in HIV-infected patients, we found elevated levels of lipopolysaccharide (LPS) in infected animals. However, LPS levels or LPS control mechanisms like endotoxin core antibodies or LPS-binding protein did not differ between groups with different disease progression. In contrast, neopterin, a metabolic product of activated macrophages, was higher in fast progressors than in slow progressors. Conclusion Our data indicate that translocation of microbial products is not the major driving force of immune activation in HIV infection.

Background To determine the correlation between protection and humoral immune response against simian immunodeficiency virus (SIVmac251), 11 macaques were immunized with live-attenuated SIVmac239Δnef either intravenously or via the tonsils and exposed to SIVmac251 after either 6 or 15 months along with unvaccinated controls. Results Independent of the route of vaccine application, viremia was significantly reduced in vaccinees compared with controls 2 weeks post-challenge. Concomitantly, viremia correlated inversely with SIV-specific IgG, complement-mediated lysis and neutralizing antibodies and these parameters seemed to contribute to reduced viremia. During chronic infection, six monkeys controlled viremia in the circulation (two or fewer infectious units per 106 PBMCs) and showed no signs of trapping in lymphatic tissues (Appendix S1). Conclusions As no significant differences were observed throughout the study, with respect to the humoral immune response and viremia control, between the two vaccinated cohorts, mucosal immunization strategies are recommended due to more simplified application.

The gastrointestinal tract represents a major site for human and simian immunodeficiency virus (HIV and SIV) replication and CD4+T-cell depletion. Despite severe depletion of mucosal CD4+T cells, FOXP3+regulatory CD4+T cells (Treg) are highly increased in the gut mucosa of chronically HIV-infected individuals and may contribute to HIV pathogenesis, either by their immunosuppressive function or as a significant target cell population for virus production. Little is known about the susceptibility of mucosal Tregto viral infection and the longitudinal effect of HIV/SIV infection on Tregdynamics. In this study, we determined the level of SIV infection in Tregand nonregulatory CD4+T cells (non-Treg) isolated from the colon of SIV-infected rhesus macaques. The dynamics of mucosal Tregand alterations in the mucosal CD4+T-cell pool were examined longitudinally. Our findings indicate that mucosal Tregwere less susceptible to productive SIV infection than non-Tregand thus were selectively spared from SIV-mediated cell death. In addition to improved survival, local expansion of Tregby SIV-induced proliferation of the mucosal CD4+T-cell pool facilitated the accumulation of mucosal Tregduring the course of infection. High frequency of mucosal Tregin chronic SIV infection was strongly related to a reduction of perforin-expressing cells. In conclusion, this study suggests that mucosal Tregare less affected by productive SIV infection than non-Tregand therefore spared from depletion. Although SIV production is limited in mucosal Treg, Tregaccumulation may indirectly contribute to viral persistence by suppressing antiviral immune responses.

In this study we investigated the efficacy of a multigenic DNA prime/modified vaccinia Ankara (MVA)boost vaccine approach, followed by mucosal challenge with highly pathogenic simian-human immunodeficiency virus (SHIV) 89.6P, using different routes for vaccine delivery. After three times of DNA priming (SIVmac239, GagPol, and SHIV 89.6P Env) one vaccine group of monkeys was immunized with MVA systemically via intramuscular (IM) and intradermal (ID) application, and in another vaccine group the MVA booster immunization comprised the IM, ID, and atraumatic oral route. Although all vaccinees became infected after intra-rectal challenge with SHIV 89.6P, substantial protection as indicated by lower peak and set point viral loads and unambiguous preservation of CD4 T cells could be achieved. As we could only transiently detect low levels of neutralizing antibodies in some vaccinees, these antibodies did not seem to add to the protection in the vaccinees. Our results indicate that both preventive multigenic DNA prime/MVA booster immunization strategies promote the control of virus replication and protect from disease progression. We also demonstrated that combining mucosal and systemic vaccination mediated better protective effects compared to systemic vaccination alone.

Comprehensive knowledge of immunoglobulin genetics is required to advance our understanding of B cell biology. Validated immunoglobulin variable (V) gene databases are close to completion only for human and mouse. We present a novel computational approach, IgDiscover, that identifies germline V genes from expressed repertoires to a specificity of 100%. IgDiscover uses a cluster identification process to produce candidate sequences that, once filtered, results in individualized germline V gene databases. IgDiscover was tested in multiple species, validated by genomic cloning and cross library comparisons and produces comprehensive gene databases even where limited genomic sequence is available. IgDiscover analysis of the allelic content of the Indian and Chinese-origin rhesus macaques reveals high levels of immunoglobulin gene diversity in this species. Further, we describe a novel human IGHV3-21 allele and confirm significant gene differences between Balb/c and C57BL6 mouse strains, demonstrating the power of IgDiscover as a germline V gene discovery tool., Current databases of V genes for antibody repertoire have limitations. Here Corcoran et al. develop a computational approach named IgDiscover that can identify germline V gene sequences from expressed antibody repertoires to high specificity and completeness.

In both human immunodeficiency virus-infected humans and simian immunodeficiency virus (SIV)-infected macaques, genes encoded in the major histocompatibility complex (MHC) class I region are important determinants of disease progression. However, compared to the human human lymphocyte antigen complex, the macaque MHC region encodes many more class I genes. Macaques with the same immunodominant class I genes express additional Mhc genes with the potential to influence the disease course. We therefore assessed the association between of the Mhc class I haplotypes, rather than single gene variants, and survival time in SIV-infected rhesus macaques (Macaca mulatta). DNA sequence analysis and Mhc genotyping of 245 pedigreed monkeys identified 17 Mhc class I haplotypes that constitute 10 major genotypes. Among 81 vaccination-naive, SIV-infected macaques, 71 monkeys carried at least one Mhc class I haplotype encoding only MHC antigens that were incapable of inducing an effective anti-SIV cytotoxic T lymphocytes response. Study of these macaques enabled us to relate individual Mhc class I haplotypes to slow, medium and rapid disease progression. In a post hoc analysis, classification according to disease progression was found to explain at least 48% of the observed variation of survival time.

The development of needle-free vaccines is one of the recently defined “grand challenges in global health” (H. Varmus, R. Klausner, R. Klausner, R. Zerhouni, T. Acharya, A. S. Daar, and P. A. Singer, Science 302:398-399, 2003). To explore whether a natural pathway to the inductive site of the mucosa-associated lymphatic tissue could be exploited for atraumatic immunization purposes, replication-deficient viral vector vaccines were sprayed directly onto the tonsils of rhesus macaques. Tonsillar immunization with viral vector vaccines encoding simian immunodeficiency virus (SIV) antigens induced cellular and humoral immune responses. Viral RNA levels after a stringent SIV challenge were reduced, providing a level of protection similar to that observed after systemic immunization with the same vaccines. Thus, atraumatic oral spray immunization with replication-deficient vectors can overcome the epithelial barrier, deliver the vaccine antigen to the mucosa-associated lymphatic tissue, and avoid induction of tolerance, providing a novel approach to circumvent acceptability problems of syringe and needle vaccines for children and in developing countries.

Background We received the LAP-BAND Investigational Device Exemption (IDE) from the US Food and Drug Administration in December 2004 to conduct a prospective longitudinal trial examining the safety and efficacy of laparoscopic adjustable gastric banding (LAGB) in morbidly obese adolescents ages 14 to 17 years. Objectives To report the short-term results of LAGB in the first 10 adolescents with complete 9 months of follow-up. Patients and methods Baseline characteristics and outcome data were analyzed in 10 patients enrolled between March 2005 and February 2006. Results All of the patients were girls. Their mean body mass index (+/-SD) was 50 +/- 13 kg/m, and excess weight was 171 +/- 79 pounds. Comorbidities included depression (3 patients), sleep apnea (3), hypertension (6), dyslipidemia (7), insulin resistance (9), metabolic syndrome (9), and steatohepatitis (in 4 of 5 patients with liver biopsy). Operative time was 45 +/- 9 minutes, and discharges were within 23 hours of surgery. Band-related complications were as follows: 2 dehydration, 1 pouch dilation, and 1 port revision. All of the patients lost weight, with a 9-month excess weight loss of 30% +/- 16% (range 14%-57%). Hypertension and the metabolic syndrome were resolved in 100% of patients (P = 0.04) and 80% of the patients (P = 0.01), respectively, along with significant improvement in the Pediatric Quality of Life and Beck Depression Inventory scores and a trend toward improvement in high-density lipoprotein cholesterol abnormalities (P = 0.08). Conclusions At short-term follow-up, weight loss occurred with minimal complications, leading to early resolution of major obesity-related comorbidities. Continued evaluation of the long-term safety and efficacy of LAGB as a surgical adjunct to a comprehensive obesity treatment program is warranted.

Sexually transmitted HIV-1 strains utilize the chemokine receptor CCR5 for viral entry and inhibitors targeting this coreceptor offer great promise for antiretroviral therapy. They also raise the question, however, whether viral variants exhibiting altered coreceptor interactions and resistance against these antiviral agents might still be pathogenic. In the present study, we analyzed a SIVmac239 envelope (Env) mutant (239DL) containing two mutations in the V3 loop which reduced viral entry via CCR5 by 10- to 20-fold, disrupted utilization of common alternative SIV coreceptors and changed the way Env engaged CCR5. To evaluate its replicative capacity and pathogenic potential in vivo we infected six rhesus macaques with 239DL. We found that 239DL replication was only slightly attenuated early during infection. Thereafter, a D324V change, which restored efficient CCR5 usage and coincided with 239wt-like levels of viral replication, emerged in two animals. In contrast, the viral geno- and phenotype remained stable in the other four rhesus macaques. Although these animals had about 100-fold reduced viral RNA loads relative to 239wt-infected macaques, they showed pronounced CD4 T-cell depletion in the intestinal lamina propria, and one developed opportunistic infections and died with simian AIDS. Thus, changes in the V3 loop that diminished CCR5 usage and altered Env interactions with CCR5 reduced the pathogenic potential of SIVmac in rhesus macaques but did not abolish it entirely.

Health, disease, and immune function are key areas of research in studies of ecology and evolution, but work on free-ranging primates has been inhibited by a lack of direct noninvasive measures of condition. Here, we evaluate the potential usefulness of noninvasive measurement of three biomarkers, the acute-phase proteins C-reactive protein (CRP) and haptoglobin, and neopterin, a by-product of macrophage activity.We took advantage of veterinary checks on captive rhesus (24) and long-tailed (3) macaques at the German Primate Center (DPZ) to analyze serum marker measures, before measuring concentrations in feces and urine, and evaluating relationships between matched serum, urine, and fecal concentrations. In a second study, we monitored excretion of these markers in response to simian immunodeficiency virus (SIV) infection and surgical tissue trauma, undertaken for a separate study.We found that each biomarker could be measured in each matrix. Serum and urinary concentrations of neopterin were strongly and significantly correlated, but neither haptoglobin nor CRP concentrations in excreta proxied circulating serum concentrations. Our infection study confirmed that urinary neopterin, in particular, is a reliable marker of viral infection in macaques, but also indicated the potential of urinary and fecal CRP and haptoglobin as indicators of inflammation.We highlight the potential of noninvasive markers of immune function, especially of urinary neopterin, which correlates strongly with serum neopterin, and is highly responsive to infection.

Vaccination with exogenous antigens such as recombinant viral proteins, immunodeficiency virus-derived whole inactivated virus particles, or virus-like particles (VLP) has generally failed to provide sufficient protection in animal models for AIDS. Pseudotyping VLPs with the vesicular stomatitis virus G protein (VSV-G), which is known to mediate entry into dendritic cells, might allow more efficient stimulation of immune responses. Therefore, we pseudotyped noninfectious immunodeficiency virus-like particles with VSV-G and carried out a preliminary screen of their immunogenicity and vaccination efficacy. Incorporation of VSV-G into HIV-1 VLPs led to hundred-fold higher antibody titers to HIV-1 Gag and enhancement of T cell responses in mice. Repeated vaccination of rhesus monkeys for 65 weeks with VSV-G pseudotyped simian immunodeficiency virus (SIV)-like particles (VLP[G]) provided initial evidence for efficient suppression of viral load after mucosal challenge with the SIVmac239 virus. Challenge of monkeys after a 28 week vaccination regimen with VLP[G] led to a reduction in peak viremia, but persistent suppression of viral load was not achieved. Due to limitations in the number of animals available for this study, improved efficacy of VSV-G pseudotyped VLPs in nonhuman primates could not be demonstrated. However, mouse experiments revealed that pseudotyping of VLPs with fusion-competent VSV-G clearly improves their immunogenicity. Additional strategies, particularly adjuvants, should be considered to provide greater protection against a challenge with pathogenic immunodeficiency virus.

Point mutations in SIVmac239 Nef disrupting CD4 downmodulation and enhancement of virion infectivity attenuate viral replication in acutely infected rhesus macaques, but changes selected later in infection fully restore Nef function (A. J. Iafrate et al., J. Virol. 74:9836-9844, 2000). To further evaluate the relevance of these Nef functions for viral persistence and disease progression, we analyzed an SIVmac239 Nef mutant containing a deletion of amino acids Q64 to N67 (Δ64-67Nef). This mutation inactivates the N-distal AP-2 clathrin adaptor binding element and disrupts the abilities of Nef to downregulate CD4, CD28 and CXCR4 and to stimulate viral replication in vitro. However, it does not impair the downmodulation of CD3 and class I major histocompatibility complex (MHC-I) or MHC-II and the upregulation of the MHC-II-associated invariant chain, and it has only a moderate effect on the enhancement of virion infectivity. Replication of the Δ64-67Nef variant in acutely infected macaques was intermediate between grosslynef-deleted and wild-type SIVmac239. Subsequently, three of six macaques developed moderate to high viral loads and developed disease, whereas the remaining animals efficiently controlled SIV replication and showed a more attenuated clinical course of infection. Sequence analysis revealed that the deletion innefwas not repaired in any of these animals. However, some changes that slightly enhanced the ability of Nef to downmodulate CD4 and moderately increased Nef-mediated enhancement of viral replication and infectivity in vitro were observed in macaques developing high viral loads. Our results imply that both the Nef functions that were disrupted by the Δ64-67 mutation and the activities that remained intact contribute to viral pathogenicity.

After experimental infection with simian immunodeficiency virus (SIV), intestinal endoscopy proved to be an easily tolerated, minimal invasive procedure to obtain biopsies from the gastrointestinal tract of rhesus macaques during all stages of disease. As the GI tract is affected by many opportunistic infections and immunological impairment after SIV/human immunodeficiency virus (HIV) infection, knowledge on the proviral load is an important parameter for a better understanding of disease pathogenesis. In this paper, we describe the set-up and evaluation of a quantitative competitive polymerase chain reaction (PCR) and the quantification of SIV intestinal proviral load in a long-term follow-up study of eight rhesus monkeys (Macaca mulatta) after two different routes of virus inoculation. A SIV-specific signal could be detected as early as day 3 after infection. Of 143 biopsies from the follow-up study, 85.3% showed a positive PCR. DNA copy numbers ranged from 300 to 15,000 molecules per 100,000 cells. No significant influence of the inoculation route could be shown on either proviral load or survival time, but higher SIV proviral load was associated with a more rapid progression to disease. Therefore, the amount of proviral load in intestinal biopsies may be an important prognostic value for the further course of the disease.

Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelope (Env) proteins are extensively decorated with N-glycans, predominantly of the high-mannose type. However, it is unclear how high-mannose N-glycans on Env impact viral spread. We show that exclusive modification of SIV Env with these N-glycans reduces viral infectivity and abrogates mucosal transmission, despite increasing viral capture by immune cell lectins. Thus, high-mannose N-glycans have opposed effects on SIV infectivity and lectin reactivity, and a balance might be required for efficient mucosal transmission.

We investigated the function of severely truncated simian immunodeficiency virus (SIV) Nef proteins (tNef) in vitro and in vivo. These variants emerged in rhesus monkeys infected with SIVmac239 containing a 152-bp deletion in the nef -unique region and have been suggested to enhance SIV virulence (E. T. Sawai, M. S. Hamza, M. Ye, K. E. Shaw, and P. A. Luciw, J. Virol. 74:2038-2045, 2000). We found that the tNef proteins were unable to down-regulate the cell surface expression of major histocompatibility complex class I proteins, CD4, and CD28 and neither stimulated SIV replication nor enhanced virion infectivity. The tNef proteins did efficiently down-regulate T-cell receptor (TCR):CD3 cell surface expression. Nevertheless, the SIVmac239 tnef variants were strongly attenuated in six infected juvenile rhesus macaques. Thus, while the ability of SIV Nef to down-modulate TCR:CD3 cell surface expression apparently confers a selective advantage in vivo, it is insufficient for efficient viral replication in infected macaques. Additional mutations elsewhere in SIVmac239 tnef genomes are required for a virulent phenotype.

We examined the association between adolescents' unsafe experience online, types of Internet activity, and safety practices using a questionnaire returned by 213 private school students (seventh through tenth grades) in spring 1999. One-fourth of respondents reported unsafe experiences. Types of unsafe experience varied with gender, Internet activity, and identity sharing.

The value of urinary neopterin as a predictive marker for disease progression in SIV- and HIV-2-infected rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) was assessed by comparing pre- with postinfection data. Before infection stable baselines for neopterin were observed in both species with significantly higher concentrations in cynomolgus macaques than in rhesus macaques. After infection of cynomolgus macaques with human immunodeficiency virus type 2 (HIV-2) neopterin concentrations exceeded 1.2 - 4.2 times preinfection values, whereas rhesus monkeys infected with simian immunodeficiency virus (SIV) yielded concentrations of more than 8 times above baseline. Increased neopterin concentrations always preceded seroconversion. No rise of neopterin was observed in cynomolgus macaques remaining seronegative after inoculation with HIV-2, whereas after inoculation with SIV neopterin was slightly elevated in rhesus monkeys despite remaining seronegative. In animals with high virus replication a pronounced increase of neopterin levels was followed by signs of immunodeficiency. Therefore like in HIV-1-infected man, in macaques infected with SIV or HIV-2 the urinary neopterin concentration is an early and reliably predictive marker for AIDS disease progression and reflects pathogenicity. This parameter can be easily assessed in study protocols for drug and vaccine tests in monkeys as in man.

A retrospective study was performed to characterize malignant lymphomas of 16 Simian im- munodeficiency virus (SIV)-infected rhesus monkeys (Macaca mulatta), 2-9 years of age, on the basis of clinical data, histologic and immunophenotypic results, and cell death indices compiled with the TdT-mediated X-duTP nick end labeling method. We particularly focused on providing immunohistochemical evidence of expression products of EBNA2, Bcl2, c-Myc, P21, P53, and Bc16. Results were compared with data from the literature on human HIV-associated lymphomas. According to the updated Kiel classification, the lymphomas were classified as 11 centroblastic lymphomas, three immunoblastic lymphomas, one Burkitt-like lymphoma, and one immunocytoma. Using antibodies to CD20, the B-cell origin of tumor cells was demonstrated. SIV antigen was not demonstrated in the tumor cells. Infection with rhesus lymphocryptovirus was present in 94% of the monkeys. Lymphomas revealed expression of Bc12 in 15/16 (94%), c-Myc in 14/16 (88%), P21 in 10/ 16 (63%), P53 in 12/16 (75%), and Bc16 in 1/16 (6%) monkeys. This study provided evidence that the ex- pression of these gene products, which are thought to play an important role in cell proliferation and apoptosis in HIV- and non-HIV-associated lymphomas, are also involved in the pathogenesis of lymphomas in SIV- infected rhesus monkeys. A tentative relationship between the described gene products and the cell death indices was established for the expression of Bc12. The present primate model represents a suitable animal model for studying the pathogenesis of AIDS-associated lymphomas. High-grade non-Hodgkin's lymphomas are regarded as the most frequent malignant diseases in HIV-in- fected patients. Since 1985, these lymphomas have been classified as AIDS-defining diseases. 54 Approxi- mately 4-10% of HIV-infected patients have malig- nant lymphomas. 40 In general, most lymphomas de- velop late in the course of the disease, and as life ex- pectancy of HIV-infected patients increases as a result of improvements in antiviral therapy, the frequency of the HIV-associated non-Hodgkin's lymphomas (HIV- NHL) also rises. 4,21,62 Although these lymphomas have several features in common, e.g., frequent develop- ment of a generalized lymphadenopathy (GLP) prior to lymphoma, aggressive clinical course, high malig- nancy, B-cell origin, and extranodal growth in unusual sites including gastrointestinal tract, orbita, myocardi- um, skeletal muscles, lungs, liver, gingiva, kidneys, gonads, and adrenal glands, they vary considerably in terms of histologic appearance, occurrence during the clinical course of the disease, and underlying genetic alterations.

Infection of macaques with live attenuated simian immunodeficiency virus (SIV) usually results in long-lasting efficient protection against infection with pathogenic immunodeficiency viruses. However, attenuation by deletion of regulatory genes such as nef is not complete, leading to a high viral load and fatal disease in some animals. To characterize immunological parameters and polymorphic host factors, we studied 17 rhesus macaques infected with attenuated SIVmac239ΔNU. Eight animals were able to control viral replication, whereas the remaining animals (non-controllers) displayed variable set-point viral loads. Peak viral load at 2 weeks post-infection (p.i.) correlated significantly with set-point viral load (P+ T-cell frequencies differed significantly soon after infection between controllers and non-controllers. Abnormal B-cell activation previously ascribed to Nef function could already be observed in non-controllers 8 weeks after infection despite the absence of Nef. Two non-controllers developed an AIDS-like disease within 102 weeks p.i. Virus from these animals transmitted to naïve animals replicated at low levels and the recipients did not develop immunodeficiency. This suggested that host factors determined differential viral load and subsequent disease course. Known Mhc class I alleles associated with disease progression in SIV WT infection only marginally influenced the viral load in Δnef-infected animals. Protection from SIVmac251 was associated with homozygosity for MHC class II in conjunction with a TLR7 polymorphism and showed a trend with initial viral replication. We speculated that host factors whose effects were usually masked by Nef were responsible for the different disease courses in individual animals upon infection with nef-deleted viruses.

Substitution of Y223F disrupts the ability of simian immunodeficiency virus (SIV) Nef to down-modulate major histocompatibility complex (MHC) class I from the cell surface but has no effect on other Nef functions, such as down-regulation of CD4, CD28, and CD3 cell surface expression or stimulation of viral replication and enhancement of virion infectivity. Inoculation of three rhesus macaques with the SIVmac239 Y223F-Nef variant revealed that this point mutation consistently reverts and that Nef activity in MHC class I down-modulation is fully restored within 4 weeks after infection. Our results demonstrate a strong selective pressure for a tyrosine at amino acid position 223 in SIV Nef, and they constitute evidence that Nef-mediated MHC class I down-regulation provides a selective advantage for viral replication in vivo.

Various simian immunodeficiency virus (SIV)sm/mac and simian/human immunodeficiency virus (SHIV) strains are used in different macaque species to study AIDS pathogenesis, as well as to evaluate candidate vaccine and anti-retroviral drugs efficacy. In this study we investigated the effect of route of infection, species of macaques and nature of virus stock on early plasma viral RNA load. We monitored the plasma RNA concentrations of 63 rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) infected with well-characterised virus stocks administered either by oral, rectal, vaginal or intravenous (i.v.) routes. In SIV(mac)-infected macaques, no significant difference in plasma RNA loads was observed between the rectal, oral and i.v. routes of infection. Cynomolgus macaques developed lower steady state SIV plasma RNA concentrations compared with rhesus macaques and no significant difference was observed between rectal and i.v. routes of infection. In SHIV(89.6p)-infected macaques, no difference between species or between route of infection was observed with this particular chimeric virus.

Losing the decisive virus-specific functions of both CD4(+) and CD8(+) T lymphocytes in the first weeks after immunodeficiency virus infection ultimately leads to AIDS. The SIV/rhesus monkey model for AIDS was used to demonstrate that a 4-week chemotherapeutic reduction of viral load during acute SIV infection of macaques allowed the development of a competent immune response able to control virus replication after discontinuation of treatment in two of five monkeys. Increasing SIV-specific CD4(+) T-helper-cell proliferation was found in all macaques several weeks after treatment, independent of their viral load. However, only macaques with low viral loads showed persistent T-cell reactivity of lymph node cells. In contrast to animals with higher viral loads, T-helper-cell counts and memory T-helper cells did not decline in the two macaques controlling viral replication. Lymphocyte apoptosis was consistently low in all treated macaques. In contrast, high CD8(+) lymphocyte death but only slightly increased CD4(+) lymphocyte apoptosis were observed during the first weeks after infection in untreated control animals, indicating that early apoptotic death of virus-specific CTL could be an important factor for disease development. Antiretroviral treatment early after infection obviously retained virus-specific and competent T lymphocytes, whereby a virus-specific immune response could develop in two animals able to control the viral replication after cessation of treatment.

To longitudinally determine T cell activation and turnover in early simian immunodeficiency virus (SIV) infection of macaques, immunological and virological parameters were monitored in 10 SIV-infected animals starting before infection until 40 weeks postinfection (wpi). Lymphocyte subsets in blood and lymph nodes (LNs) were characterized by three-color flow cytometry for expression of markers of activation, proliferation, and differentiation. As early as 1 wpi, CD69 expression was upregulated both on CD4+ and CD8+ T cells, indicative of an early activation of these cells. Whereas this activation led to increased proliferation, determined by expression of Ki-67, and absolute numbers of CD8+ T cells, CD4+ T cells showed a decreased expression of Ki-67 and reduced counts in blood at 2 wpi. Later, the percentage of Ki-67-expressing CD4+ T cells in blood and LNs increased again above preinfection levels in most animals but remained low in two monkeys progressing to AIDS. These findings suggest that T cells are activated after SIV infection, leading to increased T cell proliferation already in the early asymptomatic phase. In addition, we found a correlation between the capacity to regenerate CD4+ T cells by peripheral proliferation and the disease course. Moreover, our data indicate that the increased peripheral T cell proliferation during immunodeficiency virus infection is probably not caused by the effort of the immune system to maintain T cell homeostasis but may be a reflection of the ongoing immune response against the virus.

SIVmac Nef contains two N-terminal tyrosines that were proposed to be part of an SH2-ligand domain and/or a tyrosine-based endocytosis signal and a putative SH3-ligand domain (P104xxP107). In the present study, we investigated the effects of combined mutations in these tyrosine and proline residues on simian immunodeficiency virus (SIV) Nef interactions with the cellular signal transduction and endocytic machinery. We found that mutation of Y28F, Y39F, P104A, and P107A (FFAA-Nef) had little effect on Nef functions such as the association with the cellular tyrosine kinase Src, downregulation of cell surface expression of CD4 and class I major histocompatibility complex, and enhancement of virion infectivity. However, mutations in the PxxP sequence reduced the ability of Nef to stimulate viral replication in primary lymphocytes. Three macaques infected with the SIVmac239 FFAA-Nef variant showed high viral loads during the acute phase of infection. Reversions in the mutated prolines were observed between 12 and 20 weeks postinfection. Importantly, reversion of A107→P, which restored the ability of Nef to coprecipitate a 62-kDa phosphoprotein in in vitro kinase assays, did not precede the development of a high viral load. The Y28/Y39→F28/F39substitutions did not revert. In conclusion, mutations in both the tyrosine residues and the putative SH3 ligand domain apparently do not disrupt major aspects of SIV Nef function in vivo.

Human immunodeficiency virus type 2 (HIV-2) and the closely related simian immunodeficiency viruses (SIVs) frequently use the orphan receptor BOB/GPR15 in addition to the chemokine receptor CCR5 for efficient entry and replication. However, the role of BOB/GPR15 in replication and pathogenesis of HIV-2 and SIV in vivo is unclear. This study shows that a single amino acid substitution in the V3 loop of the pathogenic SIVmac239 clone, 321P-->S, impaired the ability to use BOB/GPR15 for entry and replication but had little effect on the ability to use CCR5. This envelope variant replicated with an efficiency comparable with the parental SIVmac239 isolate in rhesus macaques. Furthermore, the mutant genotype and phenotype remained stable even after the onset of immunodeficiency. These results suggest that this cofactor plays only a minor role for the pathogenicity of the HIV-2/SIVmac/SIVsm group of primate lentiviruses.

The nef gene of the pathogenic simian immunodeficiency virus (SIV) 239 clone was replaced with primary human immunodeficiency virus type 1 (HIV-1) nef alleles to investigate whether HIV-1 Nef can substitute for SIV Nef in vivo. Initially, two rhesus macaques were infected with the chimeric viruses (Nef-SHIVs). Most of the nef alleles obtained from both animals predicted intact open reading frames. Furthermore, forms containing upstream nucleotide substitutions that enhanced expression of the inserted gene became predominant. One animal maintained high viral loads and slowly progressed to immunodeficiency. nef long terminal repeat sequences amplified from this animal were used to generate a second generation of Nef-SHIVs. Two macaques, which were subsequently infected with a mixture of cloned chimeric viruses, showed high viral loads and progressed to fatal immunodeficiency. Five macaques received a single molecular clone, named SHIV-40K6. The SHIV-40K6 nef allele was active in CD4 and class I major histocompatibility complex downregulation and enhanced viral infectivity and replication. Notably, all of the macaques inoculated with SHIV-40K6 showed high levels of viral replication early in infection. During later stages, however, the course of infection was variable. Three animals maintained high viral loads and developed immunodeficiency. Of the remaining two macaques, which showed decreasing viral loads after the acute phase of infection, only one efficiently controlled viral replication and remained asymptomatic during 1.5 years of follow-up. The other animal showed an increasing viral load and developed signs of progressive infection during later stages. Our data demonstrate that HIV-1 nef can, to a large extent, functionally replace SIVmac nef in vivo.

The early events during infection with an immunodeficiency virus were followed by application of pathogenic simian immunodeficiency virus atraumatically to the tonsils of macaques. Analyses by virologic assays and in situ hybridization revealed that the infection started locally in the tonsils, a mucosal-associated lymphoid organ, and quickly spread to other lymphoid tissues. At day 3, there were few infected cells, but then the number increased rapidly, reaching a high plateau between days 4 and 7. The infection was not detected in the dendritic cell–rich squamous epithelium to which the virus was applied; instead, it was primarily in CD4 + tonsillar T cells, close to the specialized antigen-transporting epithelium of the tonsillar crypts. Transport of the virus and immune-activating stimuli across this epithelium would allow mucosal lymphoid tissue to function in the atraumatic transmission of immunodeficiency viruses.

Background & Aims: Human immunodeficiency virus (HIV) infection leads to severe immunologic and functional disturbances in the intestinal tract in late stages of the disease. Information on mucosal pathology directly after infection is limited. We characterized this early phase in rhesus macaques infected with simian immunodeficiency virus (SIV). Methods: Eight rhesus macaques were infected with SIV. Upper endoscopy was performed at defined times before and after infection. Viral load, percentage of CD4 + T cells, villus height, crypt depth, and Ki-67–positive crypt cells were analyzed in duodenal biopsy specimens. Serum β-carotene and vitamin D levels were assessed. Results: A rapid increase of duodenal SIV core protein (p27) concentration and an almost complete loss of intestinal CD4 + T cells was found within 2 weeks after infection. A decrease of villus height was observed, and the percentage of Ki-67–positive (proliferating) crypt cells increased. Serum concentrations of vitamin D decreased in 6 of 8 animals, and β-carotene concentrations decreased in 3 of 8 animals after infection. Conclusions: Mucosal SIV replication and intestinal CD4 + T cell depletion are early events in SIV-infected rhesus macaques. The structural changes of the mucosa strongly support the concept of HIV/SIV–induced enteropathy. In contrast to late-stage human HIV infection, early small intestinal villous atrophy in SIV infection is associated with crypt hyperplasia. GASTROENTEROLOGY 1999;116:1115-1123

Cerebrospinal fluid (CSF) samples were collected from 24 uninfected and 24 SIV251 MPBMC-infected rhesus monkeys during early infection and from 6 animals in a longitudinal design up to 7 months postinfection to investigate excitatory and inhibitory amino acid neurotransmitter levels. During the early infection period CSF amino acid concentrations of infected animals were not significantly different from those of uninfected animals. However, long-term studies demonstrated that gamma-aminobutyric acid (GABA) concentrations were decreased while glutamate concentrations were increased late in infection compared with the preinfection values of the same animals. Moreover, we showed that the source of increased glutamate in animals with AIDS is, at least partially, microglial cells. Our data support the hypothesis that excitotoxicity is involved in immunodeficiency virus-induced neurological disease and propose microglia as a contributor to excitotoxic damage.

Three rhesus macaques were infected with an SIVmac239 variant containing substitutions of 73/74PA→ED and 204D→R in Nef that disrupted the ability of Nef to downregulate CD4 surface expression. One of these animals, Mm8155, rapidly progressed to AIDS and died 21 weeks postinfection. During the final 5 weeks of infection, the levels of viral RNA and of p27 antigenemia were about 100-fold higher than usually observed in SIVmac239 infection. Postmortem examination revealed giant cell disease of the lymph nodes and the gastrointestinal tract, opportunistic infections, and a severe chronic enteritis. The majority of proviruses in spleen, kidney, and lymph nodes, and almost 100% of the viral RNA sequences, contained mutations of CGA→TAT in codon 17 ofnef,predicting a change of 17R→Y. The appearance of this substitution, which has recently been shown to confer the phenotype of the acutely pathogenic SIVpbj14, coincided with the dramatic increase in viral load and rapid progression to fatal disease. In comparison, reversions of 204R→D and changes of 72-74NED→DKD, which restored the ability of Nef to downregulate CD4, were already selected earlier in infection. Similarly to SIVpbj14, virus reisolated at late time points from Mm8155 replicated efficiently in unstimulated monkey lymphocytes. The Y17 substitution was not detected in 14 additional SIVmac239-infected macaques at the time of AIDS-related death or in the two slowly progressing animals initially infected with the same Nef variant. Although infection of macaques with SIV is commonly used as an animal model for HIV-1 infection in humans, this is only the second example for the emergence of an acutely lethal SIVmac Nef variant.

Increased rates of T-cell apoptosis have been detected in human immunodeficiency virus (HIV)-infected individuals and in the simian immunodeficiency model (SIV) for AIDS research. We have infected macaques with virulent SIV or SIV/HIV hybrid viruses (SHIV) of different pathogenic potentials to study the early kinetics of apoptosis in this model. Animals infected with SIV showed an increased degree of apoptosis in their peripheral blood mononuclear cells as early as 8 weeks after virus inoculation. Apoptotic cells were detected in the CD4 and CD8 cell populations of infected animals. In contrast, apathogenic SHIV did not lead to increased lymphocyte apoptosis and moderately pathogenic SHIV induced only transient apoptosis. T-cell death was temporally linked to viral replicationin vivo.Furthermore, lymphocyte apoptosis in infected macaques was associated with impaired proliferative responses of helper T-cells and with CD4 cell depletion. The monkey model described here provides the opportunity for testing early therapeutic interventions to prevent virus-induced programmed cell death and the subsequent onset of AIDS.

In humans infected with the human immunodeficiency virus (HIV), clinical disease due to human cytomegalovirus (HCMV) infection is one of the AIDS-defining diseases; HCMV is the most common opportunistic infection found postmortem. Histologically, the typical lesions are characterized by “owl's eye cells.” In rhesus monkeys infected with simian immunodeficiency virus (SIV), comparable lesions are caused by an infection with the rhesus CMV (RhCMV). The aim of this study was to investigate the incidence of productive and latent RhCMV infection in monkeys infected with SIV macaques (SIVmac). Eleven SIVmac-infected rhesus monkeys, which were euthanatized after developing AIDS-like disease, and 11 clinically healthy and uninfected animals comprised the study. The monkeys were screened serologically for RhCMV by western-blot analysis. Immunohistochemistry was performed by an indirect immunoperoxidase technique with a polyclonal rabbit RhCMV-antiserum. Lesions characteristic of RhCMV-associated diseases were detected histologically. All animals were latently RhCMV-infected. Seven of eleven (63.6%) SIV-infected macaques were productively RhCMV infected according to immunohistochemistry. RhCMV antigen was identified in the gastrointestinal tract, the hepatobiliary system, the lungs, and the testicles. Two of these seven animals showed characteristic inflammatory lesions associated with productive infection. Consequently, the CMV prevalence in SIVmac-infected rhesus monkeys and human AIDS patients is comparable.

Herpes B virus (or Herpesvirus simiae or Macacine herpesvirus 1) is endemic in many populations of macaques, both in the wild and in captivity. The virus elicits only mild clinical symptoms (if any) in monkeys, but can be transmitted by various routes, most commonly via bites, to humans where it causes viral encephalitis with a high mortality rate. Hence, herpes B constitutes a considerable occupational hazard for animal caretakers, veterinarians and laboratory personnel. Efforts are therefore being made to reduce the risk of zoonotic infection and to improve prognosis after accidental exposure. Among the measures envisaged are serological surveillance of monkey colonies and specific diagnosis of herpes B zoonosis against a background of antibodies recognizing the closely related human herpes simplex virus (HSV). 422 pentadecapeptides covering, in an overlapping fashion, the entire amino acid sequences of herpes B proteins gB and gD were synthesized and immobilized on glass slides. Antibodies present in monkey sera that bind to subsets of the peptide collection were detected by microserological techniques. With 42 different rhesus macaque sera, 114 individual responses to 18 different antibody target regions (ATRs) were recorded, 17 of which had not been described earlier. This finding may pave the way for a peptide-based, herpes B specific serological diagnostic test. peerReviewed

Altered cytokine transcription might play an important role in the pathogenesis of human immunodeficiency virus (HIV) infection in humans. The infection of rhesus macaques with simian immunodeficiency virus (SIV) provides a relevant animal model for HIV infection. Therefore, we evaluated the cyokine transcription of phytohemagglutinin (PHA)-stimulated lymphocytes in the early phase after infection of four rhesus macaques with pathogenic SIV-mac239. To determine transcription of interleukin (IL)-2, interferon (IFN)-gamma, IL-4, IL-6, and IL-10 we established a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). After inoculation with SIV, all monkeys became productively infected and developed an acquired immunodeficiency syndrome (AIDS) like disease. Infection was associated with a proliferation dysfunction of monkey lymphocytes in response to PHA. In addition, a decreasing overall cytokine transcription could be observed during the course of SIV infection. These findings demonstrate that an impairment of the lymphocyte function is associated with a reduced cytokine transcription in the early phase of an immunodeficiency virus infection. The observed differences of cytokine expression might contribute to the impaired immune response of SIV-infected monkeys and HIV-infected humans.

Background Semen and semen-derived amyloid fibrils boost HIV infection in vitro but their impact on sexual virus transmission in vivo is unknown. Here, we examined the effect of seminal plasma (SP) and semen-derived enhancer of virus infection (SEVI) on vaginal virus transmission in the SIV/rhesus macaque (Macacca mulatta) model. Results A total of 18 non-synchronized female rhesus macaques (six per group) were exposed intra-vaginally to increasing doses of the pathogenic SIVmac239 molecular clone in the presence or absence of SEVI and SP. Establishment of productive virus infection was assessed by measuring plasma viral RNA loads at weekly intervals. We found that the first infections occurred at lower viral doses in the presence of SP and SEVI compared to the control group. Furthermore, the average peak viral loads during acute infection were about 6-fold higher after exposure to SP- and SEVI-treated virus. Overall infection rates after a total of 27 intra-vaginal exposures to increasing doses of SIV, however, were similar in the absence (4 of 6 animals) and presence of SP (5 of 6), or SEVI (4 of 6). Furthermore, the infectious viral doses required for infection varied considerably and did not differ significantly between these three groups. Conclusions Semen and SEVI did not have drastic effects on vaginal SIV transmission in the present experimental setting but may facilitate spreading of virus infection after exposure to low viral doses that most closely approximate the in vivo situation.