Biology subjects

Macauley, M. S.

Publications and source records attributed to Macauley, M. S..

3 recordsLinked to original sources

bioRxiv2020

Glycoengineering of NK cells with glycan ligands of CD22 and selectins for B-cell lymphoma therapy

CD22, a member of Siglec family of sialic acid binding proteins, has restricted expression on B cells. Antibody-based agents targeting CD22 or CD20 (Rituxan) on B lymphoma and leukemia cells exhibit clinical efficacy for treating these malignancies, but also attack normal B cells leading to immune deficiency. Here, we report a chemoenzymatic glycocalyx editing strategy to introduce high-affinity and specific CD22 ligands onto NK-92MI and cytokine-induced killer (CIK) cells to achieve tumor-specific CD22 targeting. These CD22-ligand modified cells exhibited significantly enhanced tumor cell binding and killing in vitro without harming healthy B cells. For effective lymphoma cell killing in vivo we further functionalized CD22 ligand-modified NK-92MI cells with the E-selectin ligand sialyl Lewis X to promote trafficking to bone marrow. The cells containing the ligands of both CD22 and selectins resulted in the efficient suppression of B lymphoma in a xenograft model. Our results suggest that NK cells modified with glycan ligands to CD22 and selectins promote both targeted killing of B lymphoma cells and improved trafficking to sites where the cancer cells reside, respectively.

bioengineering↗

bioRxiv2020

Genetically Encoded, Multivalent Liquid Glycan Array (LiGA)

The Central Dogma of Biology does not allow for the study of glycans using DNA sequencing. We report a "Liquid Glycan Array" (LiGA) platform comprising a library of DNA barcoded M13 virions that display 30-1500 copies of glycans per phage. A LiGA is synthesized by acylation of phage pVIII protein with a dibenzocyclooctyne, followed by ligation of azido-modified glycans. Pulldown of the LiGA with lectins followed by deep sequencing of the barcodes in the bound phage decodes the optimal structure and density of the recognized glycans. The LiGA is target agnostic and can measure the glycan-binding profile of lectins such as CD22 on cells in vitro and immune cells in a live mouse. From a mixture of multivalent glycan probes, LiGAs identifies the glycoconjugates with optimal avidity necessary for binding to lectins on living cells in vitro and in vivo; measurements that cannot be performed with canonical glass slide-based glycan arrays. DedicationThe paper is dedicated to Laura L. Kiessling on the occasion of her 60th birthday.

biochemistry↗

bioRxiv2020

Selective augmentation of intestinal immunity by CD22-dependent SHP-1 control of β7 integrin expression.

The regulation of integrin expression and function controls interactions of immune cells and targets their trafficking locally and systemically. We show here that the tyrosine phosphatase SHP-1 is required for lymphocyte surface expression of the intestinal immune response-associated integrin {beta}7, but not for {beta}1 or {beta}2 integrins. Viable motheaten mice deficient for SHP-1 have less {beta}7 on T cells and lack {beta}7 on B cells. SHP-1 function is targeted in B cells by the B cell specific lectin CD22 (Siglec-2), suggesting a potential role for CD22 in {beta}7 expression. CD22-deficiency on B cells phenocopies the effects of SHP-1 haplodeficiency. Mechanistically, we show that SHP-1 suppresses {beta}7 endocytosis: internalization of {beta}7 but not {beta}1 integrin is accelerated in SHP-1+/- and CD22-/- B cells. Moreover, mutations in CD22 cytoplasmic SHP1-binding ITIM sequences reduce 4{beta}7 comparably, and loss of CD22 lectin activity has an intermediate effect suggesting a model in which the CD22 ITIM sequences recruit SHP-1 to control {beta}7 expression. Integrin 4{beta}7 selectively contributes to cell interactions in intestinal immunity. Consistent with this, CD22 deficient and SHP-1+/- B cells display reduced {beta}7-dependent homing to gut associated Peyers patches (PP); and CD22-deficiency impairs intestinal but not systemic antibody responses and delays clearance of the gut pathogen rotavirus. The results define a novel role for SHP-1 in the differential control of leukocyte integrins and an unexpected integrin {beta}7-specific role for CD22-SHP-1 interplay in mucosal immunity.

immunology↗