A preventive HIV-1 vaccine should induce HIV-1–specific broadly neutralizing antibodies (bnAbs). However, bnAbs generally require high levels of somatic hypermutation (SHM) to acquire breadth, and current vaccine strategies have not been successful in inducing bnAbs. Because bnAbs directed against a glycosylated site adjacent to the third variable loop (V3) of the HIV-1 envelope protein require limited SHM, the V3-glycan epitope is an attractive vaccine target. By studying the cooperation among multiple V3-glycan B cell lineages and their coevolution with autologous virus throughout 5 years of infection, we identify key events in the ontogeny of a V3-glycan bnAb. Two autologous neutralizing antibody lineages selected for virus escape mutations and consequently allowed initiation and affinity maturation of a V3-glycan bnAb lineage. The nucleotide substitution required to initiate the bnAb lineage occurred at a low-probability site for activation-induced cytidine deaminase activity. Cooperation of B cell lineages and an improbable mutation critical for bnAb activity defined the necessary events leading to breadth in this V3-glycan bnAb lineage. These findings may, in part, explain why initiation of V3-glycan bnAbs is rare, and suggest an immunization strategy for inducing similar V3-glycan bnAbs.
SummaryHIV-1 broadly neutralizing antibodies (bnAbs) require high levels of activation-induced cytidine deaminase (AID)-catalyzed somatic mutations for optimal neutralization potency. Probable mutations occur at sites of frequent AID activity, while improbable mutations occur where AID activity is infrequent. One bottleneck for induction of bnAbs is the evolution of viral envelopes (Envs) that can select bnAb B cell receptors (BCR) with improbable mutations. Here we define the probability of bnAb mutations and demonstrate the functional significance of key improbable mutations in three bnAb B cell lineages. We show that bnAbs are enriched for improbable mutations, which implies that their elicitation will be critical for successful vaccine induction of potent bnAb B cell lineages. We discuss a mutation-guided vaccine strategy for identification of Envs that can select B cells with BCRs that have key improbable mutations required for bnAb development.
BackgroundDuring the recent H1N1 influenza pandemic, excess morbidity and mortality was seen in young but not older adults suggesting that prior infection with influenza strains may have protected older subjects. In contrast, a history of recent seasonal trivalent vaccine in younger adults was not associated with protection.Methods and FindingsTo study hemagglutinin (HA) antibody responses in influenza immunization and infection, we have studied the day 7 plasma cell repertoires of subjects immunized with seasonal trivalent inactivated influenza vaccine (TIV) and compared them to the plasma cell repertoires of subjects experimentally infected (EI) with influenza H3N2 A/Wisconsin/67/2005. The majority of circulating plasma cells after TIV produced influenza-specific antibodies, while most plasma cells after EI produced antibodies that did not react with influenza HA. While anti-HA antibodies from TIV subjects were primarily reactive with single or few HA strains, anti-HA antibodies from EI subjects were isolated that reacted with multiple HA strains. Plasma cell-derived anti-HA antibodies from TIV subjects showed more evidence of clonal expansion compared with antibodies from EI subjects. From an H3N2-infected subject, we isolated a 4-member clonal lineage of broadly cross-reactive antibodies that bound to multiple HA subtypes and neutralized both H1N1 and H3N2 viruses. This broad reactivity was not detected in post-infection plasma suggesting this broadly reactive clonal lineage was not immunodominant in this subject.ConclusionThe presence of broadly reactive subdominant antibody responses in some EI subjects suggests that improved vaccine designs that make broadly reactive antibody responses immunodominant could protect against novel influenza strains.
This paper is the second in a series whose goal is to understand the structure of low-volume complete orientable hyperbolic 3 3 -manifolds. Using Mom technology, we prove that any one-cusped hyperbolic 3 3 -manifold with volume ≤ 2.848 \le 2.848 can be obtained by a Dehn filling on one of 21 21 cusped hyperbolic 3 3 -manifolds. We also show how this result can be used to construct a complete list of all one-cusped hyperbolic 3 3 -manifolds with volume ≤ 2.848 \le 2.848 and all closed hyperbolic 3 3 -manifolds with volume ≤ 0.943 \le 0.943 . In particular, the Weeks manifold is the unique smallest volume closed orientable hyperbolic 3 3 -manifold.
A goal for an HIV-1 vaccine is to overcome virus variability by inducing broadly neutralizing antibodies (bnAbs). One key target of bnAbs is the glycan-polypeptide at the base of the envelope (Env) third variable loop (V3). We have designed and synthesized a homogeneous minimal immunogen with high-mannose glycans reflective of a native Env V3-glycan bnAb epitope (Man9-V3). V3-glycan bnAbs bound to Man9-V3 glycopeptide and native-like gp140 trimers with similar affinities. Fluorophore-labeled Man9-V3 glycopeptides bound to bnAb memory B cells and were able to be used to isolate a V3-glycan bnAb from an HIV-1–infected individual. In rhesus macaques, immunization with Man9-V3 induced V3-glycan-targeted antibodies. Thus, the Man9-V3 glycopeptide closely mimics an HIV-1 V3-glycan bnAb epitope and can be used to isolate V3-glycan bnAbs.
Background This study was conducted to determine how malignant pleural mesothelioma (MPM) histology was associated with the use of surgery and survival. Methods Overall survival of patients with stage I–III epithelioid, sarcomatoid, and biphasic MPM in the Surveillance, Epidemiology, and End Results database from 2004–2010 was evaluated using multivariate Cox proportional hazards models. Results Of 1183 patients who met inclusion criteria, histologic subtype was epithelioid in 811 patients (69%), biphasic in 148 patients (12%), and sarcomatoid in 224 patients (19%). Median survival was 14 mo in the epithelioid group, 10 mo in the biphasic group, and 4 mo in the sarcomatoid group (P < 0.01). Cancer-directed surgery was used more often in patients with epithelioid (37%, 299/811) and biphasic (44%, 65/148) histologies as compared with patients with sarcomatoid histology (26%, 58/224; P < 0.01). Among patients who underwent surgery, median survival was 19 mo in the epithelioid group, 12 mo in the biphasic group, and 4 mo in the sarcomatoid group (P < 0.01). In multivariate analysis, surgery was associated with improved survival in the epithelioid group (hazard ratio [HR] 0.72; P < 0.01) but not in biphasic (HR 0.73; P = 0.19) or sarcomatoid (HR 0.79; P = 0.18) groups. Conclusions Cancer-directed surgery is associated with significantly improved survival for MPM patients with epithelioid histology, but patients with sarcomatoid and biphasic histologies have poor prognoses that may not be favored by operative treatment. The specific histology should be identified before treatment, so that surgery can be offered to patients with epithelioid histology, as these patients are most likely to benefit.
Summary Induction of broadly neutralizing antibodies (bnAbs) that target HIV-1 envelope (Env) is a goal of HIV-1 vaccine development. A bnAb target is the Env third variable loop (V3)-glycan site. To determine if immunization could induce antibodies to the V3-glycan bnAb binding site, we repetitively immunized macaques over a three-year period with an Env expressing V3-high mannose glycans. Env immunizations elicited plasma antibodies that neutralized HIV-1 expressing only high mannose glycans– a characteristic shared by early bnAb B cell lineage members. A rhesus recombinant monoclonal antibody from a vaccinated macaque bound to the V3-glycan site at the same amino acids as broadly neutralizing antibodies. A structure of the antibody bound to glycan revealed the three variable heavy chain complementarity determining regions formed a cavity into which glycan could insert and neutralized multiple HIV-1 isolates with high mannose glycans. Thus, HIV-1 Env vaccination induced mannose-dependent antibodies with characteristics of V3-glycan bnAb precursors.
Abstract. This paper introduces Mom technology to understand low volume hyperbolic 3-manifolds; it is used in [GMM3] and [M1] to show that the Weeks manifold is the unique closed orientable hyperbolic 3-manifold of least volume. Here we enumerate the hyperbolic Mom-n manifolds for n Ä 3, offer a conjectural enumeration when n D 4, and establish important technical results about embedding hyperbolic Mom-n manifolds into hyperbolic 3-manifolds.Mathematics Subject Classification (2010). Primary 57M50; Secondary 51M10, 51M25.
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