Novel humanized anti-CD3 antibodies induce a predominantly immunoregulatory profile in human peripheral blood mononuclear cells

Strategies for transfection of bovine mesenchymal stem cells with pBC1-anti-CD3 vector

Cells from different origins behave differently regarding the incorporation of exogenous DNA and formation of transgenic cells. Milk production of recombinant antibody may benefit from efficient transfection protocols to produce transgenic animals. In this context, the objective of this study was to verify the transfection potential of bovine mesenchymal stem cells from Wharton's jelly (MSC-WJ) and adipose tissue (MSC-AT), comparing co-transfection protocols with vectors pBC1-anti-CD3 and pEF-NEO-GFP, using transfection reagents Lipofectamine LTX with Plus Reagent or Xfect. Skin fibroblasts (FIB) were used as the control group. Forty-eight hours after transfection, neomycin was added and cells cultured for 2 weeks. Treated cells were submitted to fluorescence microscopy, flow cytometry, and PCR evaluations. Wharton's jelly cells were sensitive to treatments and started necrosis. In the flow cytometry assay, the median fluorescence was higher in adipocytes than fibroblasts, for both the Xfect (20.057 ± 1.620,7 and 10.601 ± 702,86, respectively, p < 0.05) and LTX (19.590 ± 113,84 and 10.518 ± 442,65, respectively, p < 0.05). These results, associated with evaluation of epifluorescence, demonstrated that adipocytes presented a better response to transfection than other cells, independent of the kit used. Performing PCR on co-transfected cells demonstrated the presence of anti-CD3, making this approach feasible for future experiments.

Gene expression profile of human T cells following a single stimulation of peripheral blood mononuclear cells with anti-CD3 antibodies

Background

Anti-CD3 immunotherapy was initially approved for clinical use for renal transplantation rejection prevention. Subsequently, new generations of anti-CD3 antibodies have entered clinical trials for a broader spectrum of therapeutic applications, including cancer and autoimmune diseases. Despite their extensive use, little is known about the exact mechanism of these molecules, except that they are able to activate T cells, inducing an overall immunoregulatory and tolerogenic behavior. To better understand the effects of anti-CD3 antibodies on human T cells, PBMCs were stimulated, and then, we performed RNA-seq assays of enriched T cells to assess changes in their gene expression profiles. In this study, three different anti-CD3 antibodies were used for the stimulation: two recombinant antibody fragments, namely, a humanized and a chimeric FvFc molecule, and the prototype mouse mAb OKT3.

Results

Gene Ontology categories and individual immunoregulatory markers were compared, suggesting a similarity in modulated gene sets, mainly those for immunoregulatory and inflammatory terms. Upregulation of interleukin receptors, such as IL2RA, IL1R, IL12RB2, IL18R1, IL21R and IL23R, and of inhibitory molecules, such as FOXP3, CTLA4, TNFRSF18, LAG3 and PDCD1, were also observed, suggesting an inhibitory and exhausted phenotype.

Conclusions

We used a deep transcriptome sequencing method for comparing three anti-CD3 antibodies in terms of Gene Ontology enrichment and immunological marker expression. The present data showed that both recombinant antibodies induced a compatible expression profile, suggesting that they might be candidates for a closer evaluation with respect to their therapeutic value. Moreover, the proposed methodology is amenable to be more generally applied for molecular comparison of cell receptor dependent antibody therapy.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5967-8) contains supplementary material, which is available to authorized users.

MicroRNA expression profiles in human CD3+ T cells following stimulation with anti-human CD3 antibodies

Background

Anti-CD3 therapy can induce immunosuppression by several non mutually exclusive mechanisms that have been proposed to explain the therapeutic effect the administration anti-CD3 mAb, but its immunoregulatory mechanism is still not completely clear. In T cells, microRNAs (miRNAs) regulate several pathways, including those associated with immune tolerance. Here, we report changes in miRNA expression in T cells following treatment with anti-human CD3 antibodies. Peripheral blood mononuclear cells were cultured in the presence of the monoclonal antibody OKT3 or a recombinant fragment of humanized anti-CD3. Following these treatments, the expression profiles of 31 miRNA species were assessed in T cells using TaqMan arrays.

Results

Eight of the tested miRNAs (miR-155, miR-21, miR-146a, miR-210, miR-17, miR-590-5p, miR-106b and miR-301a) were statistically significantly up- or down-regulated relative to untreated cells.

Conclusions

Stimulation of T cells with anti-human CD3 antibodies alters miRNA expression patterns, including of miRNA species associated with immune regulatory pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2442-y) contains supplementary material, which is available to authorized users.

Characterization of an In Vivo Z-DNA Detection Probe Based on a Cell Nucleus Accumulating Intrabody

Left-handed Z-DNA is a physiologically unstable DNA conformation, and its existence in vivo can be attributed to localized torsional distress. Despite evidence for the existence of Z-DNA in vivo, its precise role in the control of gene expression is not fully understood. Here, an in vivo probe based on an anti-Z-DNA intrabody is proposed for native Z-DNA detection. The probe was used for chromatin immunoprecipitation of potential Z-DNA-forming sequences in the human genome. One of the isolated putative Z-DNA-forming sequences was cloned upstream of a reporter gene expression cassette under control of the CMV promoter. The reporter gene encoded an antibody fragment fused to GFP. Transient co-transfection of this vector along with the Z-probe coding vector improved reporter gene expression. This improvement was demonstrated by measuring reporter gene mRNA and protein levels and the amount of fluorescence in co-transfected CHO-K1 cells. These results suggest that the presence of the anti-Z-DNA intrabody can interfere with a Z-DNA-containing reporter gene expression. Therefore, this in vivo probe for the detection of Z-DNA could be used for global correlation of Z-DNA-forming sequences and gene expression regulation.

The Efficacy of Humanized Antibody against the Sporothrix Antigen, gp70, in Promoting Phagocytosis and Reducing Disease Burden

Sporotrichosis is a subcutaneous mycosis distributed worldwide and is frequently reported in countries with tropical climates, as Latin America countries. We previously demonstrated that mice with sporotrichosis produce specific antibodies against a 70-kDa fungal protein, indicating that specific antibodies against this molecule may help to control the sporotrichosis. IgG1 monoclonal antibody was generated, and called mAbP6E7, in mice against a 70-kDa glycoprotein (gp70) of S. schenckii. The mAbP6E7 showed prophylactic and therapeutic activity against sporotrichosis. However, this antibody has a murine origin, and this can generate an immune response when administered to humans, precluding its use for a prolonged time. For its possible use in the treatment of human sporotrichosis, we humanized the mAbP6E7 by genetic engineering. Once expressed, the humanized antibodies had good stability and were able to bind to the 70-kDa cell wall antigens of Sporothrix schenckii and S. brasiliensis. The humanized P6E7 were able to opsonize S. schenckii yeasts, thus increasing the phagocytic index in human monocyte-derived macrophages. The treatment with humanized P6E7 decreased fungal burden in vivo. These data suggest that humanized P6E7 may have a therapeutic role in sporotrichosis.

Immunogenicity of anti-TNF biologic therapies for rheumatoid arthritis

Currently, five anti-TNF biologic agents are approved for the treatment of rheumatoid arthritis (RA): adalimumab, infliximab, etanercept, golimumab and certolizumab pegol. Formation of anti-drug antibodies (ADA) has been associated with all five agents. In the case of adalimumab and infliximab, immunogenicity is strongly linked to subtherapeutic serum drug levels and a lack of clinical response, but for the other three agents, data on immunogenicity are scarce, suggesting that further research would be valuable. Low ADA levels might not influence the efficacy of anti-TNF therapy, whereas high ADA levels impair treatment efficacy by considerably reducing unbound drug levels. Immunogenicity is not only an issue in patients treated with anti-TNF biologic agents; the immunogenicity of other therapeutic proteins, such as factor VIII and interferons, is well known and has been investigated for many years. The results of such studies suggest that investigations to determine the optimal treatment regimen (drug dosing, treatment schedule and co-medication) required to minimize the likelihood of ADA formation might be an effective and practical way to deal with the immunogenicity of anti-TNF biologic agents for RA.

A minimal cytomegalovirus intron A variant can improve transgene expression in different mammalian cell lines

The expression enhancement by cytomegalovirus promoter and different intron A (IA) variants were evaluated in CHO-K1, HepG2, HEK-293 and COS-7 cells by assessing the levels of luciferase activity. This data along with mRNA levels measurement indicated that the construct harboring an IA variant with a 200-nucleotide deletion (Δ200) had the greatest impact on increasing luciferase expression among all constructs evaluated. Based on these results, we redesigned pCMV-IA variants and cloned them into plasmids expressing a humanized antibody. These plasmids were then used to transfect CHO-K1 cells. Production of the antibody was not augmented with the Δ200 promoter variant. The 600-nucleotide deletion (Δ600) and whole IA promoter variants expressed similar levels of the recombinant protein. These data indicate that the IA-based enhanced expression of transgenes depends on a small region within the intron.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.

State of the union between metabolism and the immune system in type 2 diabetes

Lymphocytes and myeloid cells (monocyte/macrophages) have important roles in multiple types of diseases characterized by unresolved inflammation. The relatively recent appreciation of obesity, insulin resistance and type 2 diabetes (T2D) as chronic inflammatory diseases has stimulated interest in understanding the role of immune cells in metabolic imbalance. Myeloid cells regulate inflammation through cytokine production and the adipose tissue remodeling that accompanies hyper-nutrition, thus are critical players in metabolic homeostasis. More recently, multiple studies have indicated a role for T cells in obesity-associated inflammation and insulin resistance in model organisms, with parallel work indicating that pro-inflammatory changes in T cells also associate with human T2D. Furthermore, the expansion of T cells with similar antigen-binding sites in obesity and T2D indicates these diseases share characteristics previously attributed to inflammatory autoimmune disorders. Parallel pro-inflammatory changes in the B-cell compartment of T2D patients have also been identified. Taken together, these studies indicate that in addition to accepted pro-inflammatory roles of myeloid cells in T2D, pro-inflammatory skewing of both major lymphocyte subsets has an important role in T2D disease pathogenesis. Basic immunological principles suggest that alterations in lymphocyte function in obesity and T2D patients are an integral part of a feed-forward pro-inflammatory loop involving additional cell types. Importantly, the pro-inflammatory loop almost inevitably includes adipocytes, known to respond to pro-inflammatory, pro-diabetogenic cytokines originating from the myeloid and lymphoid compartments. We propose a model for inflammation in T2D that functionally links lymphocyte, myeloid and adipocyte contributions, and importantly proposes that tools for B-cell ablation or regulation of T-cell subset balance may have a place in the endocrinologist's limited arsenal.