Toxicology and Pharmacokinetic Studies in Mice and Nonhuman Primates of the Nontoxic, Efficient, Targeted Hexameric FasL: CTLA4-FasL.

Cytotoxic T-lymphocyte antigen 4 (CTLA4)-FasL, a homo-hexameric signal converter protein, is capable of inducing robust apoptosis in malignant cells of the B-cell lineage expressing its cognate B7 and Fas targets, while sparing nonmalignant ones. This fusion protein's striking proapoptotic efficacy stems from its complementary abilities to coordinately activate apoptotic signals and abrogate antiapoptotic ones. A limiting factor in translating FasL or Fas receptor agonists into the clinic has been lethal hepatotoxicity.

Dealing With Deans and Academic Medical Center Leadership: Advice From Leaders.

The 2017 Association of Pathology Chairs Annual Meeting included a session for department chairs and other department leaders on "how to deal with deans and academic medical center leadership." The session was focused on discussing ways to foster positive relationships with university, medical school, and health system leaders, and productively address issues and opportunities with them. Presentations and a panel discussion were provided by 4 former pathology chairs who subsequently have served as medical deans and in other leadership positions including university provost, medical center CEO, and health system board chair.

HuR Contributes to TRAIL Resistance by Restricting Death Receptor 4 Expression in Pancreatic Cancer Cells.

Unlabelled: Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal cancers, in part, due to resistance to both conventional and targeted therapeutics. TRAIL directly induces apoptosis through engagement of cell surface Death Receptors (DR4 and DR5), and has been explored as a molecular target for cancer treatment. Clinical trials with recombinant TRAIL and DR-targeting agents, however, have failed to show overall positive outcomes.

Can empathy, other personality attributes, and level of positive social influence in medical school identify potential leaders in medicine?

Purpose: To test the hypotheses that medical students recognized by peers as the most positive social influencers would score (1) high on measures of engaging personality attributes that are conducive to relationship building (empathy, sociability, activity, self-esteem), and (2) low on disengaging personality attributes that are detrimental to interpersonal relationships (loneliness, neuroticism, aggression-hostility, impulsive sensation seeking).

Method: The study included 666 Jefferson Medical College students who graduated in 2011-2013. Students used a peer nomination instrument to identify classmates who had a positive influence on their professional and personal development.

Identifying potential engaging leaders within medical education: The role of positive influence on peers.

Background: Previous research has paid little to no attention towards exploring methods of identifying existing medical student leaders.

Aim: Focusing on the role of influence and employing the tenets of the engaging leadership model, this study examines demographic and academic performance-related differences of positive influencers and if students who have been peer-identified as positive influencers also demonstrate high levels of genuine concern for others.

Methods: Three separate fourth-year classes were asked to designate classmates that had significant positive influences on their professional and personal development.

Fn14•TRAIL effectively inhibits hepatocellular carcinoma growth.

Background: New strategies for the treatment of hepatocellular carcinoma (HCC) are needed, given that currently available chemotherapeutics are inefficient. Since tumor growth reflects the net balance between pro-proliferative and death signaling, agents shifting the equilibrium toward the latter are of considerable interest. The TWEAK:Fn14 signaling axis promotes tumor cell proliferation and tumor angiogenesis, while TRAIL:TRAIL-receptor (TRAIL-R) interactions selectively induce apoptosis in malignant cells.

Energy transfer in "parasitic" cancer metabolism: mitochondria are the powerhouse and Achilles' heel of tumor cells.

It is now widely recognized that the tumor microenvironment promotes cancer cell growth and metastasis via changes in cytokine secretion and extracellular matrix remodeling. However, the role of tumor stromal cells in providing energy for epithelial cancer cell growth is a newly emerging paradigm. For example, we and others have recently proposed that tumor growth and metastasis is related to an energy imbalance.

CD40·FasL and CTLA-4·FasL fusion proteins induce apoptosis in malignant cell lines by dual signaling.

Evolution of apoptosis resistance in both lymphoma and leukemia cells is well documented, and induction of apoptosis in malignant cells is a major goal of cancer therapy. Up-regulation of anti-apoptotic signals is one of the mechanisms whereby resistance to apoptosis emerges. We have previously described the fusion proteins CD40·FasL and CTLA-4·FasL, which are formed from two functional membrane proteins and induce apoptosis of activated T cells.

Inhibition of effector function but not T cell activation and increase in FoxP3 expression in T cells differentiated in the presence of PP14.

Background: T-helper polarization of naïve T cells is determined by a complex mechanism that involves many factors, eventually leading to activation of Th1, Th2, or Th17 responses or alternatively the generation of regulatory T cells. Placental Protein 14 (PP14) is a 28 kDa glycoprotein highly secreted in early pregnancy that is able to desensitize T cell receptor (TCR) signaling and modulate T cell activation.

Methodology/principal Findings: Prolonged antigen-specific stimulation of T cells in the presence of PP14 resulted in an impaired secretion of IFN-γ, IL-5 and IL-17 upon restimulation, although the cells proliferated and expressed activation markers.

Fn14-TRAIL, a chimeric intercellular signal exchanger, attenuates experimental autoimmune encephalomyelitis.

Hallmarks of the pathogenesis of autoimmune encephalomyelitis include perivascular infiltration of inflammatory cells into the central nervous system, multifocal demyelination in the brain and spinal cord, and focal neuronal degeneration. Optimal treatment of this complex disease will ultimately call for agents that target the spectrum of underlying pathogenic processes. In the present study, Fn14-TRAIL is introduced as a unique immunotherapeutic fusion protein that is designed to exchange and redirect intercellular signals within inflammatory cell networks, and, in so doing, to impact multiple pathogenic events and yield a net anti-inflammatory effect.

CTLA-4 x Ig converts naive CD4+CD25- T cells into CD4+CD25+ regulatory T cells.

CTLA-4 x Ig was originally designed as an immunosuppressive agent capable of interfering with the co-stimulation of T cells. In the present study, we demonstrate that CTLA-4 x Ig, in combination with TCR ligation, has the additional capacity to convert naive CD4+CD25- T cells into Foxp3+ regulatory T (T(reg)) cells, as well as to expand their numbers. The CD4+CD25+Foxp3+ T(reg) generated by CTLA-4 x Ig treatment in vitro potently suppress effector T cells.

Smad3 and NFAT cooperate to induce Foxp3 expression through its enhancer.

The transcription factor Foxp3 is involved in the differentiation, function and survival of CD4+CD25+ regulatory T (T(reg)) cells. Details of the mechanism underlying the induction of Foxp3 expression remain unknown, because studies of the transcriptional regulation of the Foxp3 gene are limited by the small number of T(reg) cells in mononuclear cell populations. Here we have generated a model system for analyzing Foxp3 induction and, by using this system with primary T cells, we have identified an enhancer element in this gene.

CTLA-4 . FasL induces early apoptosis of activated T cells by interfering with anti-apoptotic signals.

The fusion protein CTLA-4 . FasL, a paradigmatic "trans signal converter protein", can attach to APC surfaces and in effect convert B7-activating costimulator signals into inhibitory Fas receptor-generated signals. The present study investigates CTLA-4 .

OX40 gene expression is up-regulated by chromatin remodeling in its promoter region containing Sp1/Sp3, YY1, and NF-kappa B binding sites.

OX40 is a member of the TNFR superfamily (CD134; TNFRSF4) that is expressed on activated T cells and regulates T cell-mediated immune responses. In this study, we have examined the regulation of OX40 gene expression in T cells. Low-level OX40 mRNA expression was detected in both resting T cells and the nonactivated EL4 T cell line, and was up-regulated in both types of T cells upon activation with anti-CD3 Ab.

alpha2,6-Sialylation promotes binding of placental protein 14 via its Ca2+-dependent lectin activity: insights into differential effects on CD45RO and CD45RA T cells.

Placental protein 14 (PP14; glycodelin) is a pregnancy-associated immunoregulatory protein that is known to inhibit T cells via T-cell receptor desensitization. The recent demonstration of PP14 as lectin has provided insight into how it may mediate its CD45 glycoprotein-dependent T-cell inhibition. In this study, we have investigated PP14's lectin-binding properties in detail.

Pathology as the enabler of human research.

Academic Pathology is a key player in human molecular science and in the powerful initiatives of the National Institutes of Health. Pathologists generate data crucial to virtually every molecular study of human tissue, and have the necessary skills and authority to oversee processing of human tissues for research analysis. We advocate that Academic Pathology is optimally positioned to drive the molecular revolution in study of human disease, through human tissue collection, analysis, and databasing.

Pregnancy zone protein is a carrier and modulator of placental protein-14 in T-cell growth and cytokine production.

A successful pregnancy can only occur when the maternal immune system fails to attack the allogeneic fetus. Two plasma proteins with described immunoregulatory activities, pregnancy zone protein (PZP) and placental protein-14 (PP14; also known as glycodelin-A), increase dramatically during pregnancy, prompting us to examine their potential role in mediating fetal protection. First, we demonstrated that both native PZP and its receptor-recognized monoamine-activated form (MA-PZP) bound non-covalently and specifically to PP14, exhibiting K(d) values greater than 3 microM, as determined by surface plasmon resonance.

Differential regulation of Th1/Th2 cytokine responses by placental protein 14.

The potency of TCR signaling during primary CD4+ T cell activation influences initial cytokine expression patterns and subsequent polarization toward either Th1 or Th2 subsets. In this study, we demonstrate that the T cell inhibitor placental protein 14 (PP14; glycodelin) preferentially inhibits Th1 cytokine responses and chemokine expression when present during ex vivo priming of CD4+ T cells. PP14 synergizes with exogenously added IL-4 in skewing T cell responses.

New designs for cancer vaccine and artificial veto cells: an emerging palette of protein paints.

Antigen-presenting cells (APC) can be refaced with "protein paints" that change the appearance of their T cell-oriented trans signal arrays. Our group has developed three categories of protein paints suitable for this kind of APC engineering: artificial glycosylphosphatidylinositol (GPI) proteins, palmitated-protein A:Fc*1 fusion protein conjugates, and trans signal converter proteins. Protein paints have been devised with either immune enhancement or suppression in mind.

CTLA-4. FasL induces alloantigen-specific hyporesponsiveness.

The APC:T cell interface can be effectively targeted with immunotherapeutic proteins. We previously described a unique trans signal converter protein, CTLA-4. Fas ligand (FasL), that has the inherent capacities to tether the T cell inhibitor FasL (CD95 ligand) to the surfaces of B7 (CD80 and CD86)-positive APC (via CTLA-4:B7 interaction), and in so doing, to simultaneously interfere with B7-to-CD28 T cell activation signals.

Quantitative interplay between activating and pro-apoptotic signals dictates T cell responses.

Antigen-presenting cells (APC) can express surface ligands with both T cell activating and inhibitory capacities, prompting the question of how responding T cells integrate opposing trans signals concurrently delivered by APC. To address this question in a quantitative fashion, we turned to protein transfer as a unique experimental approach that is well-suited for addressing such questions from a quantitative standpoint. Costimulatory (either B7-1*Fc(gamma1) or Fc(gamma1)*4-1BBL) and pro-apoptotic (Fc(gamma1)*FasL) Fc fusion proteins were quantitatively "painted" in varying ratios onto surrogate APC pre-coated with palmitated-protein A, the latter serving as a surface anchor.

Negative regulation of T cell activation by placental protein 14 is mediated by the tyrosine phosphatase receptor CD45.

CD45 is the major protein tyrosine phosphatase receptor on T cell surfaces that functions as both a positive and a negative regulator of T cell receptor (TCR) signaling. Although CD45 is required for the activation of TCR-associated Src family kinases, it also dephosphorylates phosphoproteins involved in the TCR-signaling cascade. This study links CD45 to the inhibitory activity of placental protein 14 (PP14), a major soluble protein of pregnancy that is now known to be a direct modulator of T cells and to function by desensitizing TCR signaling.

Lipid length controls antigen entry into endosomal and nonendosomal pathways for CD1b presentation.

CD1 proteins present various glycolipid antigens to T cells, but the cellular mechanisms that control which particular glycolipids generate T cell responses are not understood. We show here that T cell recognition of glucose monomycolate antigens with long (C(80)) alkyl chains involves the delivery of CD1b proteins and antigens to late endosomes in a process that takes several hours. In contrast, analogs of the same antigen with shorter (C(32)) alkyl chains are rapidly, but inefficiently, presented by cell surface CD1b proteins.