Brianna Dalesandro

J Immunother Cancer. 2022 Jan;10(1):e003760. doi: 10.1136/jitc-2021-003760.

ABSTRACT

The tumor microenvironment (TME) is characterized by the activation of immune checkpoints, which limit the ability of immune cells to attack the growing cancer. To overcome immune suppression in the clinic, antigen-expressing viruses and bacteria have been developed to induce antitumor immunity. However, the safety and targeting specificity are the main concerns of using bacteria in clinical practice as antitumor agents. In our previous studies, we have developed an attenuated bacterial strain (Brucella melitensis 16M ∆vjbR, henceforth Bm∆vjbR) for clinical use, which is safe in all tested animal models and has been removed from the select agent list by the Centers for Disease Control and Prevention. In this study, we demonstrated that Bm∆vjbR homed to tumor tissue and improved the TME in a murine model of solid cancer. In addition, live Bm∆vjbR promoted proinflammatory M1 polarization of tumor macrophages and increased the number and activity of CD8⁺ T cells in the tumor. In a murine colon adenocarcinoma model, when combined with adoptive transfer of tumor-specific carcinoembryonic antigen chimeric antigen receptor CD8⁺ T cells, tumor cell growth and proliferation was almost completely abrogated, and host survival was 100%. Taken together, these findings demonstrate that the live attenuated bacterial treatment can defeat cancer resistance to chimeric antigen receptor T-cell therapy by remodeling the TME to promote macrophage and T cell-mediated antitumor immunity.

PMID:34987022 | PMC:PMC8734016 | DOI:10.1136/jitc-2021-003760

medRxiv. 2021 Dec 27:2021.12.24.21268378. doi: 10.1101/2021.12.24.21268378. Preprint.

ABSTRACT

Despite the dramatic spread of Omicron globally, even among highly vaccinated populations, death rates have not increased concomitantly. These data argue that alternative immune mechanisms, beyond neutralization, may continue to confer protection against severe disease. Beyond their ability to bind and block infection, antibodies contribute to control and clearance of multiple infections via their ability to direct antiviral immunity via Fc-effector mechanisms. Thus, here we probed the ability of vaccine induced antibodies, across three COVID-19 vaccines, to drive Fc-effector activity against Omicron. Despite the significant loss of IgM, IgA and IgG binding to the Omicron Receptor Binding Domain (RBD) across BNT162b2, mRNA-1273, and CoronaVac vaccines, stable isotype binding was observed across all of these vaccines to the Omicron Spike. Compromised RBD binding IgG was accompanied by a significant loss of cross RBD-specific antibody Fcγ-receptor binding by the CoronaVac vaccine, but preservation of RBD-specific FcγR2a and Fcγ3a binding across the mRNA vaccines. Conversely, Spike-specific antibodies exhibited persistent binding to Fcγ-receptors, across all three vaccines, albeit higher binding was observed with the mRNA vaccines, marked by a selective preservation of FcγR2a and Fcγ3a binding antibodies. Thus, despite the significant to near complete loss of Omicron neutralization across several vaccine platforms against Omicron, vaccine induced Spike-specific antibodies continue to recognize the virus and recruit Fc-receptors pointing to a persistent capacity for extra-neutralizing antibodies to contribute Omicron disease attenuation.

PMID:34981072 | PMC:PMC8722615 | DOI:10.1101/2021.12.24.21268378

Emerg Microbes Infect. 2022 Dec;11(1):30-49. doi: 10.1080/22221751.2021.2011616.

ABSTRACT

Emerging studies indicate that infusion of HIV-resistant cells could be an effective strategy to achieve a sterilizing or functional cure. We recently reported that glycosylphosphatidylinositol (GPI)-anchored nanobody or a fusion inhibitory peptide can render modified cells resistant to HIV-1 infection. In this study, we comprehensively characterized a panel of newly isolated HIV-1-neutralizing antibodies as GPI-anchored inhibitors. Fusion genes encoding the single-chain variable fragment (scFv) of 3BNC117, N6, PGT126, PGT128, 10E8, or 35O22 were constructed with a self-inactivating lentiviral vector, and they were efficiently expressed in the lipid raft sites of target cell membrane without affecting the expression of HIV-1 receptors (CD4, CCR5 and CXCR4). Significantly, transduced cells exhibited various degrees of resistance to cell-free HIV-1 infection and cell-associated HIV-1 transmission, as well as viral Env-mediated cell-cell fusion, with the cells modified by GPI-10E8 showing the most potent and broad anti-HIV activity. In mechanism, GPI-10E8 also interfered with the processing of viral Env in transduced cells and attenuated the infectivity of progeny viruses. By genetically linking 10E8 with a fusion inhibitor peptide, we subsequently designed a group of eight bifunctional constructs as cell membrane-based inhibitors, designated CMI01∼CMI08, which rendered cells completely resistant to HIV-1, HIV-2, and simian immunodeficiency virus (SIV). In human CD4⁺ T cells, GPI-10E8 and its bifunctional derivatives blocked both CCR5- and CXCR4-tropic HIV-1 isolates efficiently, and the modified cells displayed robust survival selection under HIV-1 infection. Therefore, our studies provide new strategies for generating HIV-resistant cells, which can be used alone or with other gene therapy approaches.

PMID:34821542 | PMC:PMC8735881 | DOI:10.1080/22221751.2021.2011616

Life (Basel). 2021 Dec 10;11(12):1384. doi: 10.3390/life11121384.

ABSTRACT

Development of multidrug antibiotic resistance in bacteria is a predicament encountered worldwide. Researchers are in a constant hunt to develop effective antimicrobial agents to counter these dreadful pathogenic bacteria. Here we describe a chimerically engineered multimodular enzybiotic to treat a clinical isolate of methicillin-resistant Staphylococcus aureus (S. aureus). The cell wall binding domain of phage ϕ11 endolysin was replaced with a truncated and more potent cell wall binding domain from a completely unrelated protein from a different phage. The engineered enzybiotic showed strong activity against clinically relevant methicillin-resistant Staphylococcus aureus. In spite of a multimodular peptidoglycan cleaving catalytic domain, the engineered enzybiotic could not exhibit its activity against a veterinary isolate of S. aureus. Our studies point out that novel antimicrobial proteins can be genetically engineered. Moreover, the cell wall binding domain of the engineered protein is indispensable for a strong binding and stability of the proteins.

PMID:34947915 | PMC:PMC8705753 | DOI:10.3390/life11121384

Exp Hematol Oncol. 2021 Dec 18;10(1):56. doi: 10.1186/s40164-021-00250-1.

ABSTRACT

Cancer immunotherapy has made remarkable progress in the past decade. Bispecific antibodies (BsAbs) have acquired much attention as the next generation strategy of antibody-target cancer immunotherapy, which overwhelmingly focus on T cell recruitment and dual receptors blockade. So far, BsAb drugs have been proved clinically effective and approved for the treatment of hematologic malignancies, but no BsAb have been approved in solid tumors. Numerous designed BsAb drugs for solid tumors are now undergoing evaluation in clinical trials. In this review, we will introduce the formats of bispecific antibodies, and then update the latest preclinical studies and clinical trials in solid tumors of BsAbs targeting EpCAM, CEA, PMSA, ErbB family, and so on. Finally, we discuss the BsAb-related adverse effects and the alternative strategy for future study.

PMID:34922633 | PMC:PMC8684149 | DOI:10.1186/s40164-021-00250-1

Cancer Res. 2021 Dec 29:canres.2200.2021. doi: 10.1158/0008-5472.CAN-21-2200. Online ahead of print.

ABSTRACT

Antibody-peptide epitope conjugates (APEC) are a new class of modified antibody-drug conjugates that redirect T cell viral immunity against tumor cells. APECs contain a tumor-specific protease cleavage site linked to a patient-specific viral epitope, resulting in presentation of viral epitopes on cancer cells and subsequent recruitment and killing by CD8+ T cells. Here we developed an experimental pipeline to create patient-specific APECs and identified new preclinical therapies for ovarian carcinoma. Using functional assessment of viral peptide antigen responses to common viruses like cytomegalovirus (CMV) in ovarian cancer patients, a library of 192 APECs with distinct protease cleavage sequences was created using the anti-epithelial cell adhesion molecule (EpCAM) antibody. Each APEC was tested for in vitro cancer cell killing, and top candidates were screened for killing xenograft tumors grown in zebrafish and mice. These preclinical modeling studies identified EpCAM-MMP7-CMV APEC (EpCAM-MC) as a potential new immunotherapy for ovarian carcinoma. Importantly, EpCAM-MC also demonstrated robust T cell responses in primary ovarian carcinoma patient ascites samples. This work highlights a robust, customizable platform to rapidly develop patient-specific APECs.

PMID:34965933 | DOI:10.1158/0008-5472.CAN-21-2200

Mol Ther Oncolytics. 2021 Nov 29;24:43-58. doi: 10.1016/j.omto.2021.11.020. eCollection 2022 Mar 17.

ABSTRACT

PD-1/PD-L1 checkpoint blockade has achieved unprecedented success in cancer immunotherapy. Nevertheless, many immune-excluded tumors are resistant to therapy. Combination with oncolytic virotherapy may overcome resistance by inducing acute inflammation, immune cell recruitment, and remodeling of the tumor immune environment. Here, we assessed the combination of oncolytic measles vaccine (MV) vectors and PD-1/PD-L1 blockade. In the MC38cea model of measles virus oncolysis, MV combined with anti-PD-1 and MV vectors encoding anti-PD-1 or anti-PD-L1 antibodies achieved modest survival benefits compared with control MV or vectors encoding the antibody constant regions only. Analyses of tumor samples and tumor-draining lymph nodes revealed slight increases in intratumoral T cell effector cytokines as well as a shift toward an effector memory phenotype in the T cell compartment. Importantly, increased IFN-γ recall responses were observed in tumor rechallenge experiments with mice in complete tumor remission after treatment with MV encoding anti-PD-1 or anti-PD-L1 compared with control MV. These results prompted us to generate MV encoding the clinically approved agents pembrolizumab and nivolumab. Previously, we have generated MV encoding atezolizumab. We demonstrated the functionality of the novel vectors in vitro. We envision these vectors as therapeutics that induce and support durable anti-tumor immune memory.

PMID:34977341 | PMC:PMC8693420 | DOI:10.1016/j.omto.2021.11.020

Pathogens. 2021 Dec 9;10(12):1598. doi: 10.3390/pathogens10121598.

ABSTRACT

Arthropod-borne apicomplexan pathogens remain a great concern and challenge for disease control in animals and humans. In order to prevent Babesia infection, the discovery of antigens that elicit protective immunity is essential to establish approaches to stop disease dissemination. In this study, we determined that poly-N-acetylglucosamine (PNAG) is conserved among tick-borne pathogens including B. bovis, B. bigemina, B. divergens, B. microti, and Babesia WA1. Calves immunized with synthetic ß-(1→6)-linked glucosamine oligosaccharides conjugated to tetanus toxoid (5GlcNH₂-TT) developed antibodies with in vitro opsonophagocytic activity against Staphylococcus aureus. Sera from immunized calves reacted to B. bovis. These results suggest strong immune responses against PNAG. However, 5GlcNH₂-TT-immunized bovines challenged with B. bovis developed acute babesiosis with the cytoadhesion of infected erythrocytes to brain capillary vessels. While this antigen elicited antibodies that did not prevent disease, we are continuing to explore other antigens that may mitigate these vector-borne diseases for the cattle industry.

PMID:34959553 | PMC:PMC8709247 | DOI:10.3390/pathogens10121598

Adv Drug Deliv Rev. 2022 Feb;181:114085. doi: 10.1016/j.addr.2021.114085. Epub 2021 Dec 18.

ABSTRACT

There is growing interest in the role of microorganisms in human health and disease, with evidence showing that new types of biotherapy using engineered bacterial therapeutics, including bacterial derivatives, can address specific mechanisms of disease. The complex interactions between microorganisms and metabolic/immunologic pathways underlie many diseases with unmet medical needs, suggesting that targeting these interactions may improve patient treatment. Using tools from synthetic biology and chemical engineering, non-pathogenic bacteria or bacterial products can be programmed and designed to sense and respond to environmental signals to deliver therapeutic effectors. This review describes current progress in biotherapy using live bacteria and their derivatives to achieve therapeutic benefits against various diseases.

PMID:34933064 | DOI:10.1016/j.addr.2021.114085

Autoimmun Rev. 2022 Mar;21(3):103016. doi: 10.1016/j.autrev.2021.103016. Epub 2021 Dec 14.

ABSTRACT

Systemic autoimmune and inflammatory diseases have a complex and only partially known pathophysiology with various abnormalities involving all the components of the immune system. Among these components, antibodies, and especially autoantibodies are key elements contributing to autoimmunity. The interaction of antibody fragment crystallisable (Fc) and several distinct receptors, namely Fc receptors (FcRs), have gained much attention during the recent years, with possible major therapeutic perspectives for the future. The aim of this review is to comprehensively describe the known roles for FcRs (activating and inhibitory FcγRs, neonatal FcR [FcRn], FcαRI, FcεRs, Ro52/tripartite motif containing 21 [Ro52/TRIM21], FcδR, and the novel Fc receptor-like [FcRL] family) in systemic autoimmune and inflammatory disorders, namely rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, systemic sclerosis, idiopathic inflammatory myopathies, mixed connective tissue disease, Crohn's disease, ulcerative colitis, immunoglobulin (Ig) A vasculitis, Behçet's disease, Kawasaki disease, IgG4-related disease, immune thrombocytopenia, autoimmune hemolytic anemia, antiphospholipid syndrome and heparin-induced thrombocytopenia.

PMID:34915182 | DOI:10.1016/j.autrev.2021.103016

Front Immunol. 2021 Nov 23;12:732938. doi: 10.3389/fimmu.2021.732938. eCollection 2021.

ABSTRACT

Staphylococcal enterotoxin B (SEB) simultaneously crosslinks MHC class II antigen and TCR, promoting proliferation of T cells and releasing a large number of toxic cytokines. In this report, we computationally examined the possibility of using a single-chain biparatopic bispecific antibody to target SEB and prevent TCR binding. The design was inspired by the observation that mixing two anti-SEB antibodies 14G8 and 6D3 can block SEB-TCR activation, and we used 14G8-6D3-SEB tertiary crystal structure as a template. Twelve simulation systems were constructed to systematically examine the effects of the designed bispecific scFV MB102a, including isolated SEB, MB102a with different linkers, MB102a-SEB complex, MB102a-SEB-TCRβ complex, MB102a-SEB-TCR-MHC II complex, and MB102a-SEB-MHC II. Our all atom molecular dynamics simulations (total 18,900 ns) confirmed that the designed single-chain bispecific antibody may allosterically prevent SEB-TCRβ chain binding and inhibit SEB-TCR-MHC II formation. Subsequent analysis indicated that the binding of scFV to SEB correlates with SEB-TCR binding site motion and weakens SEB-TCR interactions.

PMID:34887850 | PMC:PMC8649926 | DOI:10.3389/fimmu.2021.732938

Front Cell Infect Microbiol. 2021 Nov 5;11:733564. doi: 10.3389/fcimb.2021.733564. eCollection 2021.

ABSTRACT

Infectious diseases represent one of the largest medical challenges worldwide. Bacterial infections, in particular, remain a pertinent health challenge and burden. Moreover, such infections increase over time due to the continuous use of various antibiotics without medical need, thus leading to several side effects and bacterial resistance. Our innate immune system represents our first line of defense against any foreign pathogens. This system comprises the innate lymphoid cells (ILCs), including natural killer (NK) cells that are critical players in establishing homeostasis and immunity against infections. ILCs are a group of functionally heterogenous but potent innate immune effector cells that constitute tissue-resident sentinels against intracellular and extracellular bacterial infections. Being a nascent subset of innate lymphocytes, their role in bacterial infections is not clearly understood. Furthermore, these pathogens have developed methods to evade the host immune system, and hence permit infection spread and tissue damage. In this review, we highlight the role of the different ILC populations in various bacterial infections and the possible ways of immune evasion. Additionally, potential immunotherapies to manipulate ILC responses will be briefly discussed.

PMID:34804991 | PMC:PMC8602108 | DOI:10.3389/fcimb.2021.733564

J Med Chem. 2021 Nov 25;64(22):16854-16863. doi: 10.1021/acs.jmedchem.1c01712. Epub 2021 Nov 16.

ABSTRACT

Effective anti-infective therapies are required to offset the rise in antibiotic resistance. A novel vancomycin-innate defense regulator conjugate (V-IDR1018) was constructed with multimodal functionality, including bacterial killing, biofilm eradication, and immune modulation. The conjugate killed bacteria within 30 min, exhibited potent activity against persister cells, and showed no susceptibility to antimicrobial resistance in tissue culture assays. Additionally, it stimulated the release of chemokine MCP-1 and anti-inflammatory cytokine IL-10 and suppressed pro-inflammatory IL-1β from lipopolysaccharide-stimulated white blood cells. The conjugate demonstrated ∼90% eradication efficacy when assessed against the MRSA biofilm formed on an organoid human skin equivalent. Similarly, when evaluated in a murine, high-density skin abscess infection model using MRSA or Staphylococcus epidermidis, the conjugate decreased dermonecrosis and reduced bacterial load. The exceptional in vitro and in vivo efficacy of the conjugate, in addition to its safety profile, makes it a valuable candidate to treat complex infectious diseases.

PMID:34784220 | DOI:10.1021/acs.jmedchem.1c01712

Antimicrob Agents Chemother. 2021 Nov 15:AAC0172921. doi: 10.1128/AAC.01729-21. Online ahead of print.

ABSTRACT

Resistance to β-lactams, the most used antibiotics worldwide, constitutes the major problem for treatment of bacterial infections. In the nosocomial pathogen Acinetobacter baumannii, β-lactamase-mediated resistance to the family of β-lactam antibiotics, carbapenems, has resulted in the selection and dissemination of multidrug-resistant isolates, which often cause infections characterized by high mortality rates. There is thus an urgent demand for new β-lactamase-resistant antibiotics that also inhibit their targets, penicillin-binding proteins (PBPs). As some PBPs are indispensable for biosynthesis of the bacterial cell wall and survival, we evaluated their importance for growth of A. baumannii by performing gene inactivation studies of d,d-transpeptidase domains of high-molecular mass (HMM) PBPs individually and in combination with one another. We showed that PBP3 is essential for A. baumannii survival, as deletion mutants of this d,d-transpeptidase were not viable. Inactivation of PBP1a resulted in partial cell lysis and retardation of bacterial growth, and these effects were further enhanced by additional inactivation of PBP2 but not PBP1b. Susceptibility to β-lactam antibiotics increased 4-8-fold for the A. baumannii PBP1a/PBP1b/PBP2 triple mutant and 2-4-fold for all remaining mutants. Analysis of peptidoglycan structure revealed a significant change in the muropeptide composition of the triple mutant and demonstrated that lack of d,d-transpeptidase activity of PBP1a, PBP1b, and PBP2 is compensated by an increase in l,d-transpeptidase-mediated crosslinking activity of LdtJ. Overall, our data showed that in addition to essential PBP3, simultaneous inhibition of PBP1a and PBP2 or PBPs in combination with LdtJ could represent potential strategies for design of novel drugs against A. baumannii.

PMID:34780270 | DOI:10.1128/AAC.01729-21

Small. 2021 Nov;17(45):e2103463. doi: 10.1002/smll.202103463. Epub 2021 Oct 15.

ABSTRACT

Cancer immunotherapy based on natural killer (NK) cells is demonstrated to be a promising strategy. However, NK cells are deficient in ligands that target specific tumors, resulting in limited antitumor efficacy. Here, a glycoengineering approach to imitate the chimeric antigen receptor strategy and decorate NK cells with nanobodies to promote NK-based immunotherapy in solid tumors is proposed. Nanobody 7D12, which specifically recognizes the human epidermal growth factor receptor (EGFR) that is overexpressed on many solid tumors, is coupled to the chemically synthesized DBCO-PEG₄ -GGG-NH₂ by sortase A-mediated ligation to generate DBCO-7D12. The NK92MI cells bearing azide groups are then equipped with DBCO-7D12 via bioorthogonal click chemistry. The resultant 7D12-NK92MI cells exhibit high specificity and affinity for EGFR-overexpressing tumor cells in vitro and in vivo by the 7D12-EGFR interaction, causing increased cytokine secretion to more effectively kill EGFR-positive tumor cells, but not EGFR-negative cancer cells. Importantly, the 7D12-NK92MI cells also show a wide anticancer spectrum and extensive tumor penetration. Furthermore, mouse experiments reveal that 7D12-NK92MI treatment achieves excellent therapeutic efficacy and outstanding safety. The authors' works provide a cell modification strategy using specific protein ligands without genetic manipulation and present a potential novel method for cancer-targeted immunotherapy by NK cells.

PMID:34761524 | DOI:10.1002/smll.202103463

Cell Rep Med. 2021 Oct 19;2(10):100430. doi: 10.1016/j.xcrm.2021.100430. eCollection 2021 Oct 19.

ABSTRACT

A recent study by Montalban-Arques et al.¹ in Cell Host & Microbe shows that augmenting the function of the gut microbiota reduces tumor burden. Four Clostridiales species blocked tumor growth as efficient as chemotherapy or immunotherapy in colorectal cancer and melanoma.

PMID:34755141 | PMC:PMC8561307 | DOI:10.1016/j.xcrm.2021.100430

Front Microbiol. 2021 Oct 15;12:760253. doi: 10.3389/fmicb.2021.760253. eCollection 2021.

ABSTRACT

A mutant of Listeria monocytogenes ScottA with a transposon in the 5' untranslated region of the asnB gene was identified to be hypersensitive to the antimicrobial t-cinnamaldehyde. Here, we report the functional characterization of AsnB in peptidoglycan (PG) modification and intracellular infection. While AsnB of Listeria is annotated as a glutamine-dependent asparagine synthase, sequence alignment showed that this protein is closely related to a subset of homologs that catalyze the amidation of meso-diaminopimelic acid (mDAP) residues in the peptidoglycan of other bacterial species. Structural analysis of peptidoglycan from an asnB mutant, compared to that of isogenic wild-type (WT) and complemented mutant strains, confirmed that AsnB mediates mDAP amidation in L. monocytogenes. Deficiency in mDAP amidation caused several peptidoglycan- and cell surface-related phenotypes in the asnB mutant, including formation of shorter but thicker cells, susceptibility to lysozyme, loss of flagellation and motility, and a strong reduction in biofilm formation. In addition, the mutant showed reduced invasion of human epithelial JEG-3 and Caco-2 cells. Analysis by immunofluorescence microscopy revealed that asnB inactivation abrogated the proper display at the listerial surface of the invasion protein InlA, which normally gets cross-linked to mDAP via its LPXTG motif. Together, this work shows that AsnB of L. monocytogenes, like several of its homologs in related Gram-positive bacteria, mediates the amidation of mDAP residues in the peptidoglycan and, in this way, affects several cell wall and cell surface-related properties. It also for the first time implicates the amidation of peptidoglycan mDAP residues in cell wall anchoring of InlA and in bacterial virulence.

PMID:34721369 | PMC:PMC8554201 | DOI:10.3389/fmicb.2021.760253

Adv Sci (Weinh). 2021 Oct 31:e2102545. doi: 10.1002/advs.202102545. Online ahead of print.

ABSTRACT

Damaged skin cannot prevent harmful bacteria from invading tissues, causing infected wounds and even serious tissue damage. Traditional treatments can not only kill pathogenic bacteria, but also suppress the growth of beneficial bacteria, thus destroying the balance of the damaged skin microbial ecosystem. Here, a living bacterial hydrogel scaffold is reported that accelerates infected wound healing through beneficial bacteria secreting antibacterial substances. Lactobacillus reuteri, a common probiotic, is encapsulated in hydrogel microspheres by emulsion polymerization and further immobilized in a hydrogel network by covalent cross-linking of methacrylate-modified hyaluronic acid. Owing to light-initiated crosslinking, the hydrogel dressing can be generated in situ at the wound site. This hydrogel scaffold not only protects bacteria from immune system attack, but also prevents bacteria from escaping into the local environment, thus avoiding potential threats. Both in vitro and in vivo experiments show that it has excellent ability against harmful bacteria and anti-inflammatory capabilities, promoting infected wound closure and new tissue regeneration. This work may open up new avenues for the application of living bacteria in the clinical management of infected wounds.

PMID:34719880 | DOI:10.1002/advs.202102545