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Background In male pre-pubertal cancer patients, radiation and chemotherapy impact future fertility by eradication of spermatogonial stem cells (SSCs). In macaques, spermatogenesis could be regenerated by intratesticular transplantation of SSCs, but only a small percentage of spermatozoa produced were of donor origin. Transient hormone suppression with a GnRH antagonist (GnRH-ant) enhanced spermatogenic recovery from transplanted SSCs. Objectives To evaluate donor-derived and endogenous spermatogenic recovery after SSC transplantation into irradiated monkeys and to test whether hormone suppression around the time of transplantation facilitates spermatogenic recovery. Materials and methods Testes of 15 adult rhesus monkeys were irradiated with 7 Gy and 4 months later transplanted, to one of the testes, with cryopreserved testicular cells containing SSCs from unrelated monkeys. Monkeys were either treated with GnRH-ant for 8 weeks before transplantation, GnRH-ant from 4 weeks before to 4 weeks after transplantation, or with no GnRH-ant. Tissues were harvested 10 months after transplantation. Results Two of the 15 monkeys, a control and a pre-transplantation GnRH-ant-treated, showed substantially higher levels of testicular spermatogenesis and epididymal sperm output in the transplanted side as compared to the untransplanted. Over 84% of epididymal spermatozoa on the transplanted side had the donor genotype and were capable of fertilizing eggs after intracytoplasmic sperm injection forming morulae of the donor paternal origin. Low levels of donor spermatozoa (~1%) were also identified in the epididymis of three additional monkeys. Transplantation also appeared to enhance endogenous spermatogenesis. Discussion and conclusion We confirmed that SSC transplantation can be used for restoration of fertility in male cancer survivors exposed to irradiation as a therapeutic agent. The success rate of this procedure, however, is low. The success of filling the tubules with the cell suspension, but not the GnRH-ant treatment, was related to the level of colonization by transplanted cells.

Study question Can transplanted primate testicular cells form seminiferous tubules de novo, supporting complete spermatogenesis? Summary answer Cryopreserved testicular cells from a prepubertal monkey can reorganize in an adult monkey recipient testis forming de novo seminiferous tubular cords supporting complete spermatogenesis. What is known already De novo morphogenesis of testicular tissue using aggregated cells from non-primate species grafted either subcutaneously or in the testis can support spermatogenesis. Study design, size, duration Two postpubertal rhesus monkeys (Macaca mulatta) were given testicular irradiation. One monkey was given GnRH-antagonist treatment from 8 to 16 weeks after irradiation, while the other received sham injections. At 16 weeks, cryopreserved testicular cells from two different prepubertal monkeys [43 × 106 viable (Trypan-blue excluding) cells in 260 μl, and 80 × 106 viable cells in 400 μl] were transplanted via ultrasound-guided injections to one of the rete testis in each recipient, and immune suppression was given. The contralateral testis was sham transplanted. Testes were analyzed 9 months after transplantation. Participants/materials, setting, methods Spermatogenic recovery was assessed by testicular volume, weight, histology and immunofluorescence. Microsatellite genotyping of regions of testicular sections obtained by LCM determined whether the cells were derived from the host or transplanted cells. Main results and the role of chance Transplanted testis of the GnRH-antagonist-treated recipient, but not the sham-treated recipient, contained numerous irregularly shaped seminiferous tubular cords, 89% of which had differentiating germ cells, including sperm in a few of them. The percentages of donor genotype in different regions of this testis were as follows: normal tubule, 0%; inflammatory, 0%; abnormal tubule region, 67%; whole interior of abnormal tubules, >99%; adluminal region of the abnormal tubules, 92%. Thus, these abnormal tubules, including the enclosed germ cells, were derived de novo from the donor testicular cells. Large scale data Not applicable. Limitations, reasons for caution The de novo tubules were observed in only one out of the two monkeys transplanted with prepubertal donor testicular cells. Wider implications of the findings These findings may represent a promising strategy for restoration of fertility in male childhood cancer survivors. The approach could be particularly useful in those exposed to therapeutic agents that are detrimental to the normal development of the tubule somatic cells affecting the ability of the endogenous tubules to support spermatogenesis, even from transplanted spermatogonial stem cells. Study funding/competing interest(s) This work was supported by research grants P01 HD075795 from Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD/NIH) to K.E.O and Cancer Center Support Grant P30 CA016672 from NCI/NIH to The University of Texas MD Anderson Cancer Center. The authors declare that they have no competing interests.

With nearly 40% of U.S. adults obese, and childhood and adolescent rates rising, obesity and associated comorbidities are serious public health concerns with massive societal costs. Often, lifestyle interventions do not offer sufficient weight loss to improve health, requiring surgery and medications as adjunct management strategies. Here, we present a 4-month case study in which the sustained, low-dose, and constant administration of the thyroid receptor β selective agonist GC-1 (sobetirome) from a novel nanochannel membrane implant was assessed in an obese, pre-diabetic rhesus macaque. Dramatic loss of white adipose tissue in the abdomen from 36 to 18% was observed via magnetic resonance imaging in conjunction with normalized serum insulin and glycemia, with no signs of cardiotoxicity shown. The non-human primate study highlights sustained low-dose delivery of GC-1 from our minimally invasive subcutaneous implant as a valuable approach to induce weight loss and manage obesity and comorbidities, including type 2 diabetes.

Vaccine development efforts against HIV-1 have been hindered because of the high mutation rate of the virus, and limitations for direct testing of HIV antigens in animal models to discern the nature of protective immunity. We developed a multivalent vaccine comprised of highly conserved HIV envelope peptide cocktail focused on priming antigen-specific helper T cell and CTL responses. Here we report protection of rhesus macaques against pathogenic SHIV(89.6P) challenge through priming cell-mediated immunity by prophylactic vaccination with the peptide-cocktail delivered by dendritic cells. Compared to monkeys mock-vaccinated or immunized with the peptide cocktail using IFA, vaccination with peptide cocktail-pulsed DC showed significant protection from AIDS-associated mortality and reduction in plasma viremia to undetectable levels.

An effective vaccine against human immunodeficiency virus (HIV) should not only protect from infection and development of acquired immunodeficiency syndrome (AIDS), but also prevent potential transmission to naïve partners. We recently reported protection of rhesus macaques from chronic simian-human immunodeficiency virus (SHIV) infection and AIDS by an HIV envelope peptide-cocktail vaccine. In the present case study, we observed that one of the vaccinated females, with undetectable circulating virus, when housed in a pair with a naïve male, did not transmit the infection over a 35-week period of social contact. Subsequent experimental challenge of the male with the same SHIV strain resulted in high-level infection and transmission to its female cage-mate. However, the virus was undetectable in the female by 12 weeks without further vaccination, validating the multivalent peptide cocktail vaccine approach in the SHIV-rhesus model, and suggesting its potential utility as an HIV vaccine strategy for humans.

Infection of Indian-origin rhesus macaques by the simian human immunodeficiency virus (SHIV) is considered to be a suitable preclinical model for directly testing efficacy of vaccine candidates based on the HIV-1 envelope. We used this model for prophylactic vaccination with a peptide-cocktail comprised of highly conserved HIV-1 envelope sequences immunogenic/antigenic in macaques and humans. Separate groups of macaques were immunized with the peptide-cocktail by intravenous and subcutaneous routes using autologous dendritic cells (DC) and Freund's adjuvant, respectively. The vaccine elicited antigen specific IFN-gamma-producing cells and T-cell proliferation, but not HIV-neutralizing antibodies. The vaccinated animals also exhibited efficient cross-clade cytolytic activity against target cells expressing envelope proteins corresponding to HIV-1 strains representative of multiple clades that increased after intravenous challenge with pathogenic SHIV(KU2). Virus-neutralizing antibodies were either undetectable or present only transiently at low levels in the control as well as vaccinated monkeys after infection. Significant control of plasma viremia leading to undetectable levels was achieved in majority of vaccinated monkeys compared to mock-vaccinated controls. Monkeys vaccinated with the peptide-cocktail using autologous DC, compared to Freund's adjuvant, and the mock-vaccinated animals, showed significantly higher IFN-gamma production, higher levels of vaccine-specific IFN-gamma producing CD4(+) cells and significant control of plasma viremia. These results support DC-based vaccine delivery and the utility of the conserved HIV-1 envelope peptide-cocktail, capable of priming strong cell-mediated immunity, for potential inclusion in HIV vaccination strategies.

Based on our prior studies in mouse, monkey, chimpanzee, and human experimental systems, we identified six peptides encoded by highly conserved regions of the human immunodeficiency virus type 1 (HIV-1) envelope gene that selectively induce cellular immune responses in the absence of anti-viral antibody production. We tested a cocktail of the six peptides as a prototype vaccine for protection from simian human immunodeficiency virus (SHIV) infection and acquired immunodeficiency syndrome (AIDS) in a rhesus monkey model. Three monkeys were vaccinated with the peptide cocktail in Freund’s adjuvant followed by autologous dendritic cells (DC) pulsed with these peptides. All the vaccinated animals exhibited significant induction of T-cell proliferation and cytotoxic T lymphocytes (CTL) responses, but no neutralizing antibodies. Two control mock-vaccinated monkeys showed no specific immune responses. Upon challenge with the pathogenic SHIV KU-2 , both the control and vaccinated monkeys were infected, but efficient clearance of virus-infected cells was observed in all the three vaccinated animals within 14 weeks. These animals also experienced a boosting of antiviral cellular immune responses after infection, and maintained antigen-specific IFN-γ-producing cells in circulation beyond 42 weeks post-challenge. In contrast, the two mock-vaccinated monkeys had low to undetectable cellular immune responses and maintained significant levels of viral-infected cells and infectious virus in circulation. Further, in both the control monkeys plasma viremia was detectable beyond 38 weeks post-challenge indicating chronic phase infection. In one control monkey, the CD4 + cells dropped to very low levels by 2 weeks post-challenge and became undetectable by week 39 coinciding with high plasma viremia and AIDS, which included cachexia and ataxia. These results serve as proof of principle for the effectiveness of the HIV envelope peptide cocktail vaccine against chronic infection and AIDS, and support the development of multivalent peptide-based vaccine as a viable strategy to induce cell-mediated immunity (CMI) for protection against HIV and AIDS in humans.

Neonatal macaques were completely protected against oral challenge with SHIV-vpu+, a simian-human immunodeficiency virus that encodes the envelope gene of a laboratory-adapted HIV strain, by pre- and post-natal treatment with a triple combination of human neutralizing monoclonal antibodies (mAbs). The mAbs were directed either against the CD4 binding site, a glycosylation-dependent gp120 epitope, or against a linear epitope on gp41. This triple combination was highly synergistic in vitro and neutralized primary HIV completely. Subsequently, oral challenge was performed with pathogenic SHIV89.6P, an animal-passaged variant of a chimeric virus that encodes the envelope gene of the primary, dual-tropic HIV89.6. Only post-natal treatment with a similar triple mAb combination was used. One out of 4 mAb-treated infants was completely protected from infection. In the other 3 treated animals, there was a tendency towards lower peak viral RNA loads compared with untreated controls. Two out of 4 mAb-treated infants maintained normal CD4+ T-cell numbers, in contrast to all controls that had steep declines at 2 weeks post-challenge. We conclude that the triple mAb combination significantly protected the neonates, even against mucosal challenge with pathogenic SHIV89.6P. Passively administered synergistic human mAbs may play a role in preventing mother-infant transmission of HIV, both against intrapartum transmission as well as against infection through breast milk. As passive immunization is a tool to assess correlates of immune protection, we conclude that the epitopes recognized by the mAbs in our combinations are important for AIDS vaccine development. Future passive immunization studies may reveal other important conserved epitopes.

Although maternal human immunodeficiency virus type 1 (HIV-1) transmission occurs during gestation, intrapartum and postpartum (by breast-feeding), 50-70% of all infected children seem to acquire HIV-1 shortly before or during delivery. Epidemiological evidence indicates that mucosal exposure is an important aspect of intrapartum HIV transmission. A simian immunodeficiency virus (SIV) macaque model has been developed that mimics the mucosal exposure that can occur during intrapartum HIV-1 transmission. To develop immunoprophylaxis against intrapartum HIV-1 transmission, we used SHIV-vpu+ (refs. 5,6), a chimeric simian-human virus that encodes the env gene of HIV-IIIB. Several combinations of human monoclonal antibodies against HIV-1 have been identified that neutralize SHIV-vpu+ completely in vitro through synergistic interaction. Here, we treated four pregnant macaques with a triple combination of the human IgG1 monoclonal antibodies F105, 2G12 and 2F5. All four macaques were protected against intravenous SHIV-vpu+ challenge after delivery. The infants received monoclonal antibodies after birth and were challenged orally with SHIV-vpu+ shortly thereafter. We found no evidence of infection in any infant during 6 months of follow-up. This demonstrates that IgG1 monoclonal antibodies protect against mucosal lentivirus challenge in neonates. We conclude that epitopes recognized by the three monoclonal antibodies are important determinants for achieving substantial protection, thus providing a rational basis for AIDS vaccine development.

In this study, the normal distribution of renal weight and volume was determined and the correlation between the weight and volume and various skeletal measurements taken from radiographs and at necropsy was assessed. Values from 136 female monkeys with complete data (including all bone, radiographic, and kidney measurements) were analyzed. The mean kidney weight was 13 g with a standard deviation (SD) of 2 g. The mean kidney volume was 12 ml, SD 2 ml. The estimation of kidney weight and volume from bone length, age, or body weight was not reliable according to statistical analysis of our data. We did find that all apparently normal adult female rhesus monkeys typically have similar sized kidneys. This information is useful in that it reduces concerns about consistency in experimental subjects.