A combined adjuvant approach primes robust germinal center responses and humoral immunity in non-human primates.

Adjuvants and antigen delivery kinetics can profoundly influence B cell responses and should be critically considered in rational vaccine design, particularly for difficult neutralizing antibody targets such as human immunodeficiency virus (HIV). Antigen kinetics can change depending on the delivery method. To promote extended immunogen bioavailability and to present antigen in a multivalent form, native-HIV Env trimers are modified with short phosphoserine peptide linkers that promote tight binding to aluminum hydroxide (pSer:alum).

Comparison of fine-needle aspiration techniques.

Background: Fine-needle aspiration (FNA) has been reported since 1912 beginning with the use of trocars and other specialized instruments that were impractical. Since then, FNA has proven to be a successful alternative technique to excisional biopsy for some assays despite a few limitations.

Methods: In this study, we compared four different techniques for FNA in rhesus macaques by evaluating total live cells recovered and cell viability using a standard 6 mL syringe and 1.

Multi-site proficiency testing for validation and standardization of assays to detect specific pathogen-free viruses, coronaviruses, and other agents in nonhuman primates.

In efforts to increase rigor and reproducibility, the USA National Primate Research Centers (NPRCs) have focused on qualification of reagents, cross-laboratory validations, and proficiency testing for methods to detect infectious agents and accompanying immune responses in nonhuman primates. The pathogen detection working group, comprised of laboratory scientists, colony managers, and leaders from the NPRCs, has championed the effort to produce testing that is reliable and consistent across laboratories. Through multi-year efforts with shared proficiency samples, testing percent agreement has increased from as low as 67.

Tuberculosis-associated IFN-I induces Siglec-1 on tunneling nanotubes and favors HIV-1 spread in macrophages.

While tuberculosis (TB) is a risk factor in HIV-1-infected individuals, the mechanisms by which (Mtb) worsens HIV-1 pathogenesis remain scarce. We showed that HIV-1 infection is exacerbated in macrophages exposed to TB-associated microenvironments due to tunneling nanotube (TNT) formation. To identify molecular factors associated with TNT function, we performed a transcriptomic analysis in these macrophages, and revealed the up-regulation of Siglec-1 receptor.

Characterization of heart macrophages in rhesus macaques as a model to study cardiovascular disease in humans.

Rhesus macaques are physiologically similar to humans and, thus, have served as useful animal models of human diseases including cardiovascular disease. The purpose of this study was to characterize the distribution, composition, and phenotype of macrophages in heart tissues of very young (fetus: 0.5 years, n = 6), young adult (2-12 years, n = 12), and older adult (13-24 years, n = 9) rhesus macaques using histopathology and immunofluorescence microscopy.

Lack of susceptibility in neonatally infected rhesus macaques to simian immunodeficiency virus-induced encephalitis.

Despite combination antiretroviral therapies making HIV a chronic rather than terminal condition for many people, the prevalence of HIV-associated neurocognitive disorders (HAND) is increasing. This is especially problematic for children living with HIV. Children diagnosed HAND rarely display the hallmark pathology of HIV encephalitis in adults, namely infected macrophages and multinucleated giant cells in the brain.

Overexpression and activation of colony-stimulating factor 1 receptor in the SIV/macaque model of HIV infection and neuroHIV.

In the present study, we investigated whether colony-stimulating factor 1 receptor (CSF1R) is expressed on brain macrophages and microglia in the human and macaque brain and whether it is upregulated and activated after lentivirus infection in vivo and contributes to development of encephalitic lesions. We examined, using multi-label and semi-quantitative immunofluorescence microscopy, the protein expression level and cellular localization of CSF1R in brain tissues from uninfected controls and SIV-infected adult macaques with or without encephalitis and also from uninfected controls, HIV-infected encephalitic subjects and virally suppressed subjects. In the normal uninfected brain, CSF1R protein was detected only on microglia and brain macrophages but not on neurons, astrocytes or oligodendrocytes.

Shifting Dynamics of Intestinal Macrophages during Simian Immunodeficiency Virus Infection in Adult Rhesus Macaques.

The intestinal tract is a primary barrier to invading pathogens and contains immune cells, including lymphocytes and macrophages. We previously reported that CD163CD206 (single-positive [SP]) interstitial macrophages of the lung are short-lived and succumb early to SIV infection. Conversely, CD163CD206 (double-positive [DP]) alveolar macrophages are long-lived, survive after SIV infection, and may contribute to the virus reservoir.

Tuberculosis Exacerbates HIV-1 Infection through IL-10/STAT3-Dependent Tunneling Nanotube Formation in Macrophages.

The tuberculosis (TB) bacillus, Mycobacterium tuberculosis (Mtb), and HIV-1 act synergistically; however, the mechanisms by which Mtb exacerbates HIV-1 pathogenesis are not well known. Using in vitro and ex vivo cell culture systems, we show that human M(IL-10) anti-inflammatory macrophages, present in TB-associated microenvironment, produce high levels of HIV-1. In vivo, M(IL-10) macrophages are expanded in lungs of co-infected non-human primates, which correlates with disease severity.

Rapid Turnover and High Production Rate of Myeloid Cells in Adult Rhesus Macaques with Compensations during Aging.

Neutrophils, basophils, and monocytes are continuously produced in bone marrow via myelopoiesis, circulate in blood, and are eventually removed from circulation to maintain homeostasis. To quantitate the kinetics of myeloid cell movement during homeostasis, we applied 5-bromo-2'-deoxyuridine pulse labeling in healthy rhesus macaques () followed by hematology and flow cytometry analyses. Results were applied to a mathematical model, and the blood circulating half-life and daily production, respectively, of each cell type from macaques aged 5-10 y old were calculated for neutrophils (1.

Role of Monocyte/Macrophages during HIV/SIV Infection in Adult and Pediatric Acquired Immune Deficiency Syndrome.

Monocytes/macrophages are a diverse group of cells that act as first responders in innate immunity and then as mediators for adaptive immunity to help clear infections. In performing these functions, however, the macrophage inflammatory responses can also contribute to pathogenesis. Various monocyte and tissue macrophage subsets have been associated with inflammatory disorders and tissue pathogeneses such as occur during HIV infection.

Mesenchymal stem cell therapy for the treatment of amyotrophic lateral sclerosis: signals for hope?

Based on the distinctive cellular, molecular and immunomodulatory traits of mesenchymal stem cells (MSC), it has been postulated that these cells may play a critical role in regenerative medicine. In addition to the participation of MSC in the repair of mesodermal-derived tissues (bone, cartilage), robust data have suggested that MSC may also play a reparative role in conditions involving damage of cells of ectodermal origin. The above content has been supported by the capability of MSC to differentiate into neuron-like cells as well as by a competence to generate a 'neuroprotective' environment.

Presence of osteoclast precursor cells during ex vivo expansion of bone marrow-derived mesenchymal stem cells for autologous use in cell therapy.

Background Aims: To obtain a cell product competent for clinical use in terms of cell dose and biologic properties, bone marrow-derived mesenchymal stem cells (MSCs) must be expanded ex vivo.

Methods: A retrospective analysis was performed of records of 76 autologous MSC products used in phase I or II clinical studies performed in a cohort of cardiovascular patients. In all cases, native MSCs present in patient bone marrow aspirates were separated and expanded ex vivo.

Mesenchymal stem cells and the treatment of conditions and diseases: the less glittering side of a conspicuous stem cell for basic research.

Not too long ago, several motivated and forward-looking articles were published describing the cellular and molecular properties of mesenchymal stem cells (MSCs), specially highlighting their potential for self-renewal, commitment, differentiation, and maturation into specific mesoderm-derived lineages. A very influential publication of that period entitled "Mesenchymal stem cells: No longer second class marrow citizens" [1] raised the point of view that "…challenges to harness MSC cell therapy to treat diseases … need to wait for the full comprehension that marrow is a rich source of mesenchyme-derived cells whose potential is still far from fully appreciated." Whether or not the prophecy of Gerson was fulfilled, in the last 8 years it has become evident that infusing MSCs into patients suffering a variety of disorders represents a viable option for medical treatment.

Intravenous administration of multipotent stromal cells prevents the onset of non-alcoholic steatohepatitis in obese mice with metabolic syndrome.

Background & Aims: Metabolic syndrome is secondary to obesity and characterized by dyslipidemia, insulin resistance, and hypertension. Non-alcoholic fatty liver disease is its hepatic manifestation, whose progression-limiting step is non-alcoholic steatohepatitis (NASH). The latter is characterized by lipid accumulation, hepatocyte damage, leukocyte infiltration, and fibrosis.

Replenishment of type VII collagen and re-epithelialization of chronically ulcerated skin after intradermal administration of allogeneic mesenchymal stromal cells in two patients with recessive dystrophic epidermolysis bullosa.

In animal models it has been shown that mesenchymal stromal cells (MSC) contribute to skin regeneration and accelerate wound healing. We evaluated whether allogeneic MSC administration resulted in an improvement in the skin of two patients with recessive dystrophic epidermolysis bullosa (RDEB; OMIM 226600). Patients had absent type VII collagen immunohistofluorescence and since birth had suffered severe blistering and wounds that heal with scarring.

Restriction of HIV-1 by APOBEC3G is cytidine deaminase-dependent.

Cytidine deamination is the primary mechanism by which APOBEC3G restricts HIV-1; however, several studies have reported that APOBEC3G also inhibits virus replication via a mechanism that is independent of deamination. Using active site APOBEC3G mutants, we have re-evaluated the biological relevance of deaminase-independent APOBEC3G-mediated restriction of HIV-1. APOBEC3G proteins with Glu-->Ala mutations in AS1, AS2 or AS1 and AS2 were stably expressed at physiological levels in CEM-SS T cells and 293T cells and the ability of the cells to support Deltavif HIV-1 replication was then tested.

Dynamic of distribution of human bone marrow-derived mesenchymal stem cells after transplantation into adult unconditioned mice.

Background: The use of mesenchymal stem cells (MSC) for cell therapy relies on their capacity to engraft and survive long-term in the appropriate target tissue(s). Animal models have demonstrated that the syngeneic or xenogeneic transplantation of MSC results in donor engraftment into the bone marrow and other tissues of conditioned recipients. However, there are no reliable data showing the fate of human MSC infused into conditioned or unconditioned adult recipients.

Human cord blood-derived mesenchymal stem cells home and survive in the marrow of immunodeficient mice after systemic infusion.

Bone marrow is the residence site of mesenchymal stem cells (MSC), which upon commitment and maturation develop into several mesenchymal phenotypes. Recently, we have described the presence of MSC in human cord blood (cbMSC) and informed that their properties are the same as those for MSC obtained from adult bone marrow. In this study we have investigated the capability of transplanted cbMSC to home and survive in the marrow of unconditioned nude mice.

Validation in mesenchymal progenitor cells of a mutation-independent ex vivo approach to gene therapy for osteogenesis imperfecta.

Over 100 dominant-negative mutations within the COL1A1 gene have been identified in osteogenesis imperfecta (OI). In terms of human therapeutics, targeting each of these mutations independently is unlikely to be feasible. Here we show that the hammerhead ribozyme Rzpol1a1, targeting a common polymorphism within transcripts from the COL1A1 gene, downregulates COL1A1 transcript in human mesenchymal progenitor cells at a ribozyme to transcript ratio of only 1:1.