Project description:Direct probing of germinal center responses reveals immunological features and bottlenecks for nAb responses to an engineered HIV trimer
Project description:Generation of Tier 2 HIV neutralizing antibody (nAb) responses by immunization remains a challenging problem, and the immunological barriers to induction of such responses by Env immunogens remain unclear. We explored these barriers by combining a suite of innovative techniques, including longitudinal lymph node fine needle aspirates, germinal center (GC) B cell lineage tracking, and a new method for detecting and quantifying GC T follicular helper (GC Tfh) cells, in non-human primates immunized with a native-like HIV-1 Env trimer protein (BG505 SOSIP.v5.2). A majority of immunized animals (9/12) developed Tier 2 neutralizing antibodies (nAb). Tier 2 nAb development best correlated with GC B cell magnitude in response to later booster immunizations and the quality of the Tfh help. Notably, these immunological factors distinguished between qualitatively successful and unsuccessful vaccine Ab responses, as they correlated with nAb development but did not correlate with simple Env Ab binding titers. Therefore, direct probing of germinal centers in future vaccine trials is key, as this suite of technically robust approaches provides quantitation of the proximal immune correlates of neutralizing antibody development and could allow redesign of optimal multi-stage vaccination schedules.
Project description:Cytokine-independent detection of antigen-specific germinal center T follicular helper (Tfh) cells in immunized non-human primates using a live cell Activation Induced Marker (AIM) technique
Project description:Mucosal vaccination with attenuated Mycobacterium tuberculosis induces strong central memory responses and protects against tuberculosis
Project description:Mass spectrometry based proteomics has facilitated sperm composition studies in several mammalian species but no studies have been undertaken in non-human primate species. Here we report the analysis of the 1247 proteins that comprise the Rhesus macaque (Macaca mulatta) sperm proteome (termed the MacSP). Comparative analysis with previously characterized mouse and human sperm proteomes reveals substantial levels of orthology (47% and 40% respectively) and widespread overlap of functional categories based on Gene Ontology analyses. Approximately 10% of macaque sperm genes (113/1247) are significantly under-expressed in the testis as compared with other tissues, which may reflect proteins specifically acquired during epididymal maturation. Phylogenetic and genomic analyses of three MacSP ADAMs (A-Disintegrin and Metalloprotease proteins), ADAM18-, 20- and 21-like, provides empirical support for sperm genes functioning in non-human primate taxa which have been subsequently lost in the lineages leading to humans. The MacSP contains proteasome proteins of the 20S core subunit, the 19S proteasome activator complex and an alternate proteasome activator PA200, raising the possibility that proteasome activity is present in mature sperm. Robust empirical characterization of the Rhesus sperm proteome should greatly expand the possibility for targeted molecular studies of spermatogenesis and fertilization in a commonly used model species for human infertility.
Project description:Liver Macrophage Infiltration and Inflammation are associated with Antiviral Responses During SIV Infection in Macaques that is Only Partly Reduced during cART
Project description:Plasmodium knowlesi, a model malaria parasite, is responsible for a significant portion of zoonotic malaria cases in Southeast Asia and must be controlled to avoid disease severity and fatalities. However, little is known about the host-parasite interactions and molecular mechanisms in play during the course of P. knowlesi malaria infections, which also may be relevant across Plasmodium species. Here we contrast P. knowlesi sporozoite-initiated infections in Macaca mulatta and Macaca fascicularis using whole blood RNA-sequencing and transcriptomic analysis. These macaque hosts are evolutionarily close, yet malaria-naïve M. mulatta will succumb to blood-stage infection without treatment, whereas malaria-naïve M. fascicularis controls parasitemia without treatment. This comparative analysis reveals transcriptomic differences as early as the liver phase of infection, in the form of signaling pathways that are activated in M. fascicularis, but not M. mulatta. Additionally, while most immune responses are initially similar during the acute stage of the blood infection, significant differences arise subsequently. The observed differences point to prolonged inflammation and anti-inflammatory effects of IL10 in M. mulatta, while M. fascicularis undergoes a transcriptional makeover towards cell proliferation, consistent with its recovery. Together, these findings suggest that timely detection of P. knowlesi in M. fascicularis, coupled with control of inflammation while initiating the replenishment of key cell populations, helps contain the infection. Overall, this study points to specific genes and pathways that could be investigated as a basis for new drug targets that support recovery from acute malaria.