Effects of Chronic Viral Infection on Lymphocyte Populations in Middle-aged Baboons (Papio anubis).

Aging of the immune system is characterized by the loss of naïve T-cells, increased inflammation, and immune function impairment. Chronic infection with cytomegalovirus is thought to play a role in age-related changes in immunity. Therefore, to assess the effect of pathogens such as cytomegalovirus on the immune system, we determined lymphocyte populations and inflammatory markers over a 3-y period in captive, middle-age baboons, with various exposure to pathogens and shedding pressure. Groups included SPF (i.e., pathogen-negative; n = 14); large-group, conventionally housed (CONV LG; pathogen- positive; n = 14), and small-group, conventionally housed (CONV SM; pathogen-positive; n = 7). All baboon groups showed a decrease in CD45RA+ CD28+ (i.e., naive) cells over time during middle age, but the rate of decline appeared faster in CONV LG baboons than in the other groups. In addition, the reduction in CD45RA+ CD28+ cells in the CONV LG baboons coincided with higher IgG levels against baboon cytomegalovirus, increased serum cortisol concentration, and a greater inflammatory phenotype. The results of this project support a role for cytomegalovirus infection in immune system alterations in middle-aged baboons.

Characterization of Baboon Cytomegalovirus Infection in Healthy Adult Baboons (Papio anubis).

Cytomegalovirus (CMV) is a common chronic herpesvirus found in humans and numerous other mammalian species. In people, chronic viruses like CMV can alter overall health and immunity and pose a serious risk for those with an inadequate immune system. In addition, CMV plays an important role in animal health, and could affect the health of vulnerable populations, like endangered species. Previous studies found a high rate of CMV seropositivity among adult baboons (Papio anubis), and results from our laboratory revealed that baboon CMV (BaCMV) seropositivity was correlated with altered immune cell populations. In the current study, we further characterized BaCMV infection in normal, adult baboons. Analysis of blood samples from baboons (age, 6 to 26 y) revealed a low overall prevalence of detectable of BaCMV DNA, with a higher detection rate in aged baboons (older than 15 y). Furthermore, data suggest that individual baboons maintain similar rates of recurrence and levels of BaCMV shedding in saliva over time. Finally, we evaluated multiple commercially available assays for antihuman CMV IgG and IgM for use with baboon sera. Results of this study will improve our understanding of BaCMV and may be directly relevant to other closely related species.

Pilot Study to Assess the Efficacy of Ivermectin and Fenbendazole for Treating Captive-Born Olive Baboons (Papio anubis) Coinfected with Strongyloides fülleborni and Trichuris trichiura.

In this study, we evaluated the efficacy of combined treatment with ivermectin and fenbendazole (IVM-FBZ) for treating captive olive baboons (Papio anubis) infected with Strongyloides fülleborni and Trichuris trichiura, 2 common nematode parasites of these NHP. Infected baboons were treated for a total of 9 wk with ivermectin (400 µg/kg IM twice weekly) and fenbendazole (50 mg/kg PO once daily for 3 d; 3 rounds of treatment, 21 d apart). Five baboons naturally infected with both S. fülleborni and T. trichiura (n = 4) or S. fülleborni alone (n = 1) received the combination therapy; an additional baboon infected with both parasites served as a nontreated control. The efficacy of IVM-FBZ was measured as the reduction in fecal egg counts of S. fülleborni and T. trichiura as determined by quantitative fecal flotation examination after treatment of baboons with IVM-FBZ. All baboons treated with IVM-FBZ stopped shedding S. fülleborni and T. trichiura eggs by 8 d after treatment and remained negative for at least 161 d. The nontreated control baboon shed S. fülleborni and T. trichiura eggs throughout the study period. Our results indicate that the IVM-FBZ regimen was efficacious for treating olive baboons infected with S. fülleborni and T. trichiura.

An oral HemokineTM, α-methylhydrocinnamate, enhances myeloid and neutrophil recovery following irradiation in vivo.

An oral therapeutic which reduces duration of cytopenias and is active following accidental radiation exposures is an unmet need in radiation countermeasures. Alpha methylhydrocinnamate (ST7) prolongs STAT-5 phosphorylation, reduces growth-factor dependency of multi-lineage cell lines, and stimulates erythropoiesis. Here, ST7 and its isomers were studied for their effects on myeloid progenitors and hematopoietic stem cells (HSCs) following radiation, in nonhuman primates, and murine irradiation models. Addition of ST7 or ST7-S increased CFU-GM production by 1.7-fold (p<0.001), reduced neutrophil apoptosis comparable to G-CSF, and enhanced HSC survival post-radiation by 2-fold, (p=0.028). ST7 and ST7-S administered in normal baboons increased ANC and platelet counts by 50-400%. In sub-lethally-irradiated mice, ANC nadir remained >200/mm3 and neutropenia recovered in 6days with ST7 treatment and 18days in controls (p<0.05). In lethally-irradiated mice, marrow pathology at 15days was hypocellular (10% cellularity) in controls, but normal (55-75% cellularity) with complete neutrophil maturation with ST7-S treatment. Following lethal irradiation, ST7, given orally for 4days, reduced mortality, with 30% survival in ST7-animals vs 8% in controls, (p<0.05). Collectively, the studies indicate that ST7 and ST7-S enhance myeloid recovery post-radiation and merit further evaluation to accelerate hematologic recovery in conditions of radiation-related and other marrow hypoplasias.

PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage.

A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt's disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75-80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic.

Novel Inducers of Fetal Globin Identified through High Throughput Screening (HTS) Are Active In Vivo in Anemic Baboons and Transgenic Mice.

High-level fetal (γ) globin expression ameliorates clinical severity of the beta (ß) hemoglobinopathies, and safe, orally-bioavailable γ-globin inducing agents would benefit many patients. We adapted a LCR-γ-globin promoter-GFP reporter assay to a high-throughput robotic system to evaluate five diverse chemical libraries for this activity. Multiple structurally- and functionally-diverse compounds were identified which activate the γ-globin gene promoter at nanomolar concentrations, including some therapeutics approved for other conditions. Three candidates with established safety profiles were further evaluated in erythroid progenitors, anemic baboons and transgenic mice, with significant induction of γ-globin expression observed in vivo. A lead candidate, Benserazide, emerged which demonstrated > 20-fold induction of γ-globin mRNA expression in anemic baboons and increased F-cell proportions by 3.5-fold in transgenic mice. Benserazide has been used chronically to inhibit amino acid decarboxylase to enhance plasma levels of L-dopa. These studies confirm the utility of high-throughput screening and identify previously unrecognized fetal globin inducing candidates which can be developed expediently for treatment of hemoglobinopathies.

The effects of age and cytomegalovirus on markers of inflammation and lymphocyte populations in captive baboons.

The human immune system undergoes age-related changes that can lead to increased disease susceptibility. Using the baboon as a model for human immune system aging, we examined age-related changes in relative and absolute numbers of T cell subpopulations, cytomegalovirus (CMV) titer and markers of inflammation. In addition, the effect of gender, social status and peer group on lymphocyte subpopulations was determined. Relative and absolute numbers of total lymphocytes (CD3+), T helper cells (CD4+), and cytotoxic T cells (CD8+) increased with age. The proportion of naïve T cells (CD45RA+) decreased, while the total number of cells negative for the co-stimulatory receptor, CD28 (CD28-) increased in an age-dependent manner. Furthermore, CMV titers were negatively correlated with the number of naive CD4+ cells. IL-6 and cortisol concentration were also negatively associated with T cell subpopulations. Additionally, socially dominant baboons exhibited decreases in naïve CD4+ and CD8+ cells (by 65% and 52%, respectively) compared to subordinate animals. These results suggest that factors such as CMV exposure and inflammation may contribute to the age-related decline in immune health and indicate that factors like social status should be considered when studying immunosenescence in animal models.

Longevity of Sm-p80-specific antibody responses following vaccination with Sm-p80 vaccine in mice and baboons and transplacental transfer of Sm-p80-specific antibodies in a baboon.

Based on data obtained using vaccine efficacy studies in mice, hamsters, and baboons, the credentials of Sm-p80 as a first tier vaccine candidate for schistosomiasis have been well established. Sm-p80-based vaccine formulation(s) have consistently exhibited potent prophylactic efficacy in reducing adult worm burden following cercarial challenge and induce killing of established adult worms in chronic infection. This vaccine is protective against both intestinal and urinary schistosomiasis. In this study, the longevity of Sm-p80-specific antibody responses was studied in mice and in baboons. Robust antibody titers were detected in mice for up to 60 weeks following vaccination with Sm-p80 recombinant vaccine (Sm-p80 + GLA-SE). In the follow-up experiments to our published studies, Sm-p80-specific IgG was also detected in baboons 5-8 years following the initial vaccination with an Sm-p80 DNA vaccine. In one baboon, transfer of Sm-p80-specific antibody was detected in umbilical cord blood and in the baby. These long-lasting humoral immune response data coupled with the vaccine efficacy data in rodents and nonhuman primates further strengthens the case for Sm-p80 to be moved forward through development leading to human clinical trials.

Cross-species protection: Schistosoma mansoni Sm-p80 vaccine confers protection against Schistosoma haematobium in hamsters and baboons.

The ability of the Schistosoma mansoni antigen, Sm-p80, to provide cross-species protection against Schistosoma haematobium challenge was evaluated in hamster and baboon models. Pronounced reduction in worm burden (48%) and in tissue egg load (64%) was observed in hamsters vaccinated with recombinant Sm-p80 admixed with glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE). Similarly, in baboons, the Sm-p80/GLA-SE vaccine produced a 25% reduction in S. haematobium adult worms and decreased the egg load in the urinary bladder by 64%. A 40% and 53% reduction in fecal and urine egg output, respectively, was observed in vaccinated baboons. A balanced pro-inflammatory (Th17 and Th1) and Th2 type of response was generated after vaccination and appears indicative of augmented prophylactic efficacy. These data on cross-species protection coupled with the prophylactic, therapeutic and antifecundity efficacy against the homologous parasite, S. mansoni, reinforces Sm-p80 as a promising vaccine candidate. It is currently being prepared for GMP-compliant manufacture and for further pre-clinical development leading to human clinical trials. These results solidify the expectation that the Sm-p80 vaccine will provide relief for both the intestinal and the urinary schistosomiasis and thus will be greatly beneficial in reducing the overall burden of schistosomiasis.

Use of an Sm-p80-based therapeutic vaccine to kill established adult schistosome parasites in chronically infected baboons.

No vaccines are available for human use for any parasitic infections, including the helminthic disease schistosomiasis. Sm-p80, the large subunit of Schistosoma mansoni calpain, is a leading antigen candidate for a schistosomiasis vaccine. Prophylactic and antifecundity efficacies of Sm-p80 have been tested using a variety of vaccine approaches in both rodent and nonhuman primate models. However, the therapeutic efficacy of a Sm-p80-based vaccine had not been determined. In this study, we evaluated the therapeutic efficacy of Sm-p80 by using 2 different strategies and 3 Sm-p80-based vaccine formulations in baboons. Vaccine formulations were able to decrease established adult worms by 10%-36%, reduce retention of eggs in tissues by 10%-57%, and decrease egg excretion in feces by 13%-33%, compared with control formulations. Marked differences were observed in B and T cell immune correlates between vaccinated and control animals. This is the first report of killing of established adult schistosome worms by a vaccine. In addition to distinct prophylactic efficacy of Sm-p80, this study adds to the evidence that Sm-p80 is a potentially important antigen with both substantial prophylactic and therapeutic efficacies. These data reinforce that Sm-p80 should be moved forward along the path toward human clinical trials.

Simian T-lymphotropic Virus-associated lymphoma in 2 naturally infected baboons: T-cell clonal expansion and immune response during tumor development.

Two young female baboons naturally infected with simian T-lymphotropic virus type 1 (STLV1) were euthanized due to chronic respiratory disease that was unresponsive to treatment. Massive lymphocytic infiltration of the lung interstitium suggested a diagnosis of STLV-associated lymphoma. In each case, the diagnosis was confirmed through inverse PCR (IPCR) that detected monoclonally integrated STLV1 provirus in cellular DNA extracted from lymphoma tissue and peripheral blood cells (PBC). One dominant STLV1-infected T-cell clone and 3 minor clones were detected in PBC from each baboon. Using archived PBC DNA and primers within the proviral genome and chromosomal DNA flanking the STLV1 integration sites in PCR analyses, we determined that the dominant clone in one baboon had first appeared approximately 8 mo after infection and had circulated for 4 y before clinical disease developed. ELISA testing of archived serum revealed that both baboons seroconverted to the p19 and p24 gag proteins and the envelope gp46 protein but not to the viral tax protein. Titers to p24 and gp46 rose significantly after infection and remained relatively constant until death, whereas titers to p19 increased with time. Although spontaneous STLV1-associated lymphomas have been described in baboons, the STLV1-associated lymphomas described here occurred in 2 relatively young baboons, both of whom had become infected with STLV at 3 to 4 y of age and developed lymphoma within 5 y of infection.

Evaluation of reproduction and raising offspring in a nursery-reared SPF baboon (Papio hamadryas anubis) colony.

Baboons (Papio hamadryas anubis) of a conventional breeding colony were nursery-reared to create a specific pathogen-free (SPF) baboon-breeding program. Because the founding generations were nursery-reared until 2 years of age, it was suspected that the SPF baboons would exhibit increased reproductive challenges as adults. Mothering behavior was of interest, because SPF females were not exposed to parental role models during the nursery-rearing process. We compared reproductive data from the SPF baboon breeding program during its first 10 years with data from age-matched baboons during the same period from an established, genetically-similar conventional breeding colony. We also evaluated records documenting mother-infant behaviors within the SPF colony. The average age of menarche in SPF females was 3.3 years. The overall live birth rate of both SPF and conventional females was approximately 90%, with no difference in pregnancy outcome between the two colonies. The average age at first conception for SPF females was earlier (4.2 years) than that of the conventional females (4.7 years). In both colonies, primiparous females were more likely to abort than multiparous females. Similarly, primiparous females were more likely to lose their infants to death or human intervention. A mothering score system was developed in the SPF colony to facilitate intervention of poor mother-infant relationships. Records revealed 70% of SPF mothers were able to raise one or more of their infants successfully to at least 180 days of age, which did not differ from conventional mothers. SPF females returned to post-partum amenorrhea 27 days sooner on average than the conventional females, independent of dam age. The nursery-rearing process used for recruitment into the SPF colony therefore did not have an adverse effect on reproduction or rearing offspring.

Natural infection of baboons by Entamoeba histolytica elicits anti- gal-lectin heavy subunit IgA and IgG antibodies with shared epitope specificity to that of humans.

Non-human primates, such as baboons (Papio hamadryas anubis), are natural hosts for Entamoeba species; infections can be asymptomatic or result in invasive lethal disease. It was sought to determine whether following natural infection by Entamoeba. histolytica, baboon anti-amebic antibodies recognized native Gallectin, a recombinant portion of the lectin heavy subunit (designated LC3) and specific heavy subunit epitopes; we compared the specificity of anti-amebic antibodies from baboons to that of humans following asymptomatic E. histolytica infection or cure of amebic liver abscess (ALA). Female baboons (n=54), aged one to three years of age and living in captivity were screened for infection by real time PCR. E. histolytica infection was found in 37 baboons and was associated with serum anti-LC3 IgG (73%) and anti-LC3 IgA (46%) or intestinal anti-Gal-Lectin IgA antibody responses (49%), p<0.021 for each compared to that observed with baboons having an E. dispar infection (n=10) or uninfected baboons (n=7). The ELISA OD reading for anti-LC3 or anti-lectin antibodies correlated strongly with the presence of a PCR CT value indicative of E. histolytica infection. In humans with asymptomatic E. histolytica infection or those recently cured of ALA, 63% and 57% had serum anti- LC3 IgA and 65% and 57% had serum anti-LC3 IgG antibodies respectively. Epitope- specific synthetic peptides were used as capture antigens in ELISA; for baboons that possessed anti-LC3 and anti-lectin antibodies, 74% had anti-peptide IgG or IgA antibodies, compared to 86% of asymptomatic humans and 92% of ALA subjects(P>0.05).

The Baboon (Papio spp.) as a model of human Ebola virus infection.

Baboons are susceptible to natural Ebola virus (EBOV) infection and share 96% genetic homology with humans. Despite these characteristics, baboons have rarely been utilized as experimental models of human EBOV infection to evaluate the efficacy of prophylactics and therapeutics in the United States. This review will summarize what is known about the pathogenesis of EBOV infection in baboons compared to EBOV infection in humans and other Old World nonhuman primates. In addition, we will discuss how closely the baboon model recapitulates human EBOV infection. We will also review some of the housing requirements and behavioral attributes of baboons compared to other Old World nonhuman primates. Due to the lack of data available on the pathogenesis of Marburg virus (MARV) infection in baboons, discussion of the pathogenesis of MARV infection in baboons will be limited.

The effect of season on inflammatory response in captive baboons.

INTRODUCTION: Highly seasonal animals demonstrate predictable changes in immune function that coincide with changes in photoperiod. Little is known about the effect of season on immune response in baboons. The objective of this study was to determine the effect of season on inflammatory response in baboons. MATERIALS AND METHODS: Peripheral blood mononuclear cell cytokine response following immune stimulation and serum markers of inflammation were assessed during each season in two groups of young male baboons: one housed under natural light and one in a controlled environment of 12 hours light:12 hours dark. RESULTS: A seasonal immune rhythm was evident in both groups, with a greater TNF-α and IL-6 response to stimulation and serum CRP concentration in June and September compared with December. CONCLUSIONS: Season is an important experimental confounder, and therefore, time of year should be controlled when designing studies and analyzing data from immune studies in baboons.

Efficacy of a Gal-lectin subunit vaccine against experimental Entamoeba histolytica infection and colitis in baboons (Papio sp.).

To determine the efficacy of a Gal-lectin based intranasal synthetic peptide vaccine, we developed a new experimental primate model of Entamoeba histolytica intestinal infection. Release of xenic E. histolytica trophozoites (5×10(6)) into the small bowel of baboons (Papio sp.) resulted in a rapid intestinal anti-amebic antibody response and a brief infection; however, release of trophozoites directly into the cecum (5 baboons) elicited a sustained E. histolytica infection, as determined by quantitative fecal PCR, and an ulcerative, inflammatory colitis observed on colonoscopy and histopathology. In three controlled experiments, baboons received four immunizations at seven day intervals of 1600 µg of the vaccine/nostril, with Cholera toxin, 20 µg/nostril as adjuvant; vaccinated (n=6) and control baboons (n=6) baboons were then challenged via colonoscopy with xenic trophozoites (5×10(6)). During 90 days of follow up, 250 of 415 (60.24%) fecal samples in control baboons had a (+) PCR for E. histolytica, compared to only 36 of 423 (8.51%) samples from vaccinated baboons (P<0.001). All 6 vaccinated baboons were free of infection by the 51st day after challenge, 5 of 6 controls positive had (+) fecal PCRs for up to 126 days post-challenge (P=0.019). Inflammatory colitis developed in 4 of 6 control baboons post-challenge, with invasive E. histolytica trophozoites present in 2 of the 4 on histopathology. There was no evidence of inflammatory colitis or parasite invasion in any of the vaccinated baboons; there was a strong inverse correlation between positive ELISA OD value indicating the presence of intestinal anti-peptide IgA antibodies and baboons having a positive fecal PCR CT value, P<0.001. In conclusion, we developed a novel primate model of E. histolytica intestinal infection and demonstrated that a Gal-lectin-based intranasal synthetic peptide vaccine was highly efficacious in preventing experimental E. histolytica infection and colitis in baboons.

Preclinical prophylactic efficacy testing of Sm-p80-based vaccine in a nonhuman primate model of Schistosoma mansoni infection and immunoglobulin G and E responses to Sm-p80 in human serum samples from an area where schistosomiasis is endemic.

The prophylactic efficacy of a schistosome antigen (Sm-p80) was tested in a nonhuman primate model, the baboon. Using a total of 28 baboons, different vaccination strategies were used including recombinant Sm-p80 protein formulated in Toll-like receptor 7 and Toll-like receptor 9 agonists, and DNA priming followed by boosting with protein plus adjuvants. Recombinant protein approaches provided levels of prophylactic efficacy of 52%-58%, whereas prime-boost approaches conferred 38%-47% protection in baboons. An appropriately balanced pro-inflammatory (T-helper 17 [Th17] and Th1) and anti-inflammatory (Th2) type of response was generated; the Th1 and Th17 types of immune responses appear to be indicative of increased prophylactic efficacy. Production and expression of several cytokines (interleukin 2 [IL-2], interferon γ, IL-12α, IL-1ß, IL-6, and IL-22) were up-regulated in vaccinated animals. Human correlate studies revealed Sm-p80 reactivity with immunoglobulin G in human serum samples from schistosome-infected individuals. In addition, a complete lack of prevailing Sm-p80-specific immunoglobulin E in a high-risk or infected population was observed, thus minimizing the risk of hypersensitivity reaction following vaccination with Sm-p80 in humans. This study provided the proof of concept to move Sm-p80 forward into further preclinical development leading to human clinical trials.

Detection and experimental transmission of a novel Babesia isolate in captive olive baboons (Papio cynocephalus anubis).

Babesia spp. are tick-transmitted apicomplexan hemoparasites that infect mammalian red blood cells. Our purpose was to determine the prevalence of Babesia infection in a colony of captive baboons and to evaluate potential experimental routes of the transmission of the hemoparasite. DNA was extracted from the blood of baboons and tested for infection with Babesia by PCR and primers that amplify the 18s rRNA gene of the parasite. The overall prevalence of infection of Babesia in the baboon population was 8.8% (73 of 830). Phylogenetic analysis of the sequenced DNA from 2 baboons revealed that the Babesia isolate found in captive baboons was a novel species most closely related (97% to 99%) to B. leo. Blood from a Babesia-infected donor baboon was inoculated intravenously, intramuscularly, or subcutaneously into 3 naive baboons. The intravenously inoculated baboon was PCR-positive at 7 d after inoculation; the 2 baboons inoculated by other routes became PCR-positive at 10 d after inoculation. All 3 baboons remained PCR-positive for Babesia through day 31. Baboons experimentally inoculated with the new Babesia isolate did not exhibit clinical signs of babesiosis during the experiments. We demonstrated that captive baboons are infected with a novel Babesia isolate. In addition we showed that Babesia can be transmitted in the absence of the organism's definitive host (ticks) by transfer of infected blood through intravenous, intramuscular, and subcutaneous routes to naive baboons.

Age-associated alteration in innate immune response in captive baboons.

Baboons are an ideal model for studies of human inflammatory response due to their physiological and immunological similarities to people; however; little is known about how age affects immune function in the baboon. We sought to determine if baboons show age-related innate immune changes similar to that described in people. Age was correlated with increased serum C-reactive protein and interleukin-6 or, however, no change in interleukin-10 concentration was observed (n = 120 baboons). Cytokine release from unstimulated peripheral blood mononuclear cells as well as following immune (lipopolysaccharide) stimulation increased with age. When whole blood was assayed, both lipopolysaccharide stimulated and unstimulated samples showed an age-related increase in interleukin-6 response, although the unstimulated cytokine response was reduced compared with that observed in peripheral blood mononuclear cells. Tumor necrosis factor-α response was not related to age. Cytokine response in lipopolysaccharide-stimulated whole blood was negatively correlated with serum DHEA-S concentration and positively correlated with TGF-ß concentration.

Novel therapeutic candidates, identified by molecular modeling, induce γ-globin gene expression in vivo.

The ß-hemoglobinopathies and thalassemias are serious genetic blood disorders affecting the ß-globin chain of hemoglobin A (α(2)ß(Α)(2)). Their clinical severity can be reduced by enhancing expression of fetal hemoglobin (γ-globin), producing HbF (α(2)γ(2,)). In studies reported here, γ-globin induction by 23 novel, structurally-unrelated compounds, which had been predicted through molecular modeling and in silico screening of a 13,000 chemical library, was evaluated in vitro in erythroid progenitors cultured from normal subjects and ß-thalassemia patients, and in vivo in transgenic mice or anemic baboons. Four predicted candidates were found to have high potency, with 4- to 8-fold induction of HbF. Two of these compounds have pharmacokinetic profiles favorable for clinical application. These studies thus effectively identified high potency γ-globin inducing candidate therapeutics and validated the utility of in silico molecular modeling.