延长腺相关病毒递送药物的半衰期提高治疗效果

延长基于蛋白质治疗药物的半衰期可以提高药物疗效。然而,基因治疗本质上是长期表达所需的治疗性药物,药物半衰期对基因治疗疗效的影响尚不清楚。在这项腺相关病毒(adeno-associated virus,AAV)基因治疗研究中,通过与免疫球蛋白G1(immunoglobulin G 1,IgG1)可溶性单体Fc区(soluble monomeric IgG1 fragment crystallizable,sFc)或Fc区融合,设计了几种能够延长半衰期的蛋白质。研究表明,延长AAV递送的小分子双功能蛋白和成纤维细胞生长因子21(fibroblast growth factor 21,FGF21)的半衰期显著增加了它们在血液循环中的浓度。此外,AAV递送FGF21延长其半衰期使2型糖尿病动物模型中肝损伤和血糖显著降低,并改善了葡萄糖耐量和胰岛素敏感性。这些结果证明了延长药物半衰期的基因治疗在应对人类疾病中的治疗潜力。

A non-ACE2 competing human single-domain antibody confers broad neutralization against SARS-CoV-2 and circulating variants

The current COVID-19 pandemic has heavily burdened the global public health system and may keep simmering for years.The frequent emergence of immune escape variants have spurred the search for prophylactic vaccines and therapeutic antibodies that confer broad protection against SARS-CoV-2 variants.Here we show that the bivalency of an affinity maturated fully human singledomain antibody(n3113.1-Fc)exhibits exquisite neutralizing potency against SARS-CoV-2 pseudovirus,and confers effective prophylactic and therapeutic protection against authentic SARS-CoV-2 in the host cell receptor angiotensin-converting enzyme 2(ACE2)humanized mice.The crystal structure of n3113 in complex with the receptor-binding domain(RBD)of SARS-CoV-2,combined with the cryo-EM structures of n3113 and spike ecto-domain,reveals that n3113 binds to the side surface of up-state RBD with no competition with ACE2.The binding of n3113 to this novel epitope stabilizes spike in up-state conformations but inhibits SARS-CoV-2 S mediated membrane fusion,expanding our recognition of neutralization by antibodies against SARS-CoV-2.Binding assay and pseudovirus neutralization assay show no evasion of recently prevalent SARS-CoV-2 lineages,including Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),and Delta(B.1.617.2)for n3113.1-Fc with Y58L mutation,demonstrating the potential of n3113.1-Fc(Y58L)as a promising candidate for clinical development to treat COVID-19.

Characterization of human IgM and IgG repertoires in individuals with chronic HIV-1 infection

Advancements in high-throughput sequencing(HTS)of antibody repertoires(Ig-Seq)have unprecedentedly improved our ability to characterize the antibody repertoires on a large scale.However,currently,only a few studies explored the influence of chronic HIV-1 infection on human antibody repertoires and many of them reached contradictory conclusions,possibly limited by inadequate sequencing depth and throughput.To better understand how HIV-1 infection would impact humoral immune system,in this study,we systematically analyzed the differences between the IgM(HIV-IgM)and IgG(HIV-IgG)heavy chain repertoires of HIV-1 infected patients,as well as between antibody repertoires of HIV-1 patients and healthy donors(HH).Notably,the public unique clones accounted for only a negligible proportion between the HIV-IgM and HIV-IgG repertoires libraries,and the diversity of unique clones in HIV-IgG remarkably reduced.In aspect of somatic mutation rates of CDR1 and CDR2,the HIV-IgG repertoire was higher than HIV-IgM.Besides,the average length of CDR3 region in HIV-IgM was significant longer than that in the HH repertoire,presumably caused by the great number of novel VDJ rearrangement patterns,especially a massive use of IGHJ6.Moreover,some of the B cell clonotypes had numerous clones,and somatic variants were detected within the clonotype lineage in HIV-IgG,indicating HIV-1 neutralizing activities.The in-depth characterization of HIV-IgG and HIV-IgM repertoires enriches our knowledge in the profound effect of HIV-1 infection on human antibody repertoires and may have practical value for the discovery of therapeutic antibodies.