Clinical and economic burden of systemic lupus erythematosus in Colombia

AIMS

Our cost-of-illness (COI) model adopted payer and societal perspectives over five years to measure the economic burden of Systemic Lupus Erythematosus (SLE) in Colombia.

MATERIALS AND METHODS

A prevalence-based model was constructed to estimate costs and economic consequences for SLE patients in Colombia. The model included four health states: three phenotypes of SLE representing mild, moderate, and severe states and death. The clinical inputs were captured from the published literature and validated by the Delphi panel. Our model measured direct medical and indirect costs, including disease management, transient events, and indirect costs. One-way sensitivity analysis was also performed.

RESULTS

The number of Colombian SLE patients was 37,498. The number of SLE patients with mild, moderate, and severe phenotypes was 5343, 28757 and 3,397, respectively. SLE-patients with moderate (Colombian pesos; COP 146 billion) and severe phenotypes (COP276 billion) incurred higher costs than those with mild phenotypes (COP2 billion), over 5 years. The total SLE cost in Colombia over five years from the payer and societal perspectives was estimated to be COP 915 billion and 8 trillion, respectively. The costs per patient per year from the payer and societal perspectives were COP 4,881,902 ($3,510) and COP 46,637,054 ($33,528), respectively.

CONCLUSION

The burden of SLE in Colombia over five years is substantially high, mainly due to the consequences of economic loss because it affects women and men of working age, in addition to the costs of SLE management and its consequences, such as flares, infection, and organ damage. Our COI indicated that disease management costs among patients with moderate and severe SLE were substantially higher than those among patients with a mild phenotype. Therefore, more attention should be paid to limiting the progression of SLE and the occurrence of flares, with the need for further economic evaluation of novel treatment strategies that help in disease control.

Lower female survival from an opportunistic infection reveals progesterone-driven sex bias in trained immunity

Immune responses differ between females and males, although such sex-based variance is incompletely understood. Observing that bacteremia of the opportunistic pathogen Burkholderia gladioli caused many more deaths of female than male mice bearing genetic deficiencies in adaptive immunity, we determined that this was associated with sex bias in the innate immune memory response called trained immunity. Female attenuation of trained immunity varies with estrous cycle stage and correlates with serum progesterone, a hormone that decreases glycolytic capacity and recall cytokine secretion induced by antigen non-specific stimuli. Progesterone receptor antagonism rescues female trained immune responses and survival from controlled B. gladioli infection to magnitudes similar to those of males. These data demonstrate progesterone-dependent sex bias in trained immunity where attenuation of female responses is associated with survival outcomes from opportunistic infection.

Current experimental methods to investigate the impact of specialized pro-resolving lipid mediators on Sjögren's syndrome

Sjögren's syndrome is a chronic inflammatory autoimmune disease characterized by diminished secretory function of the exocrine glands. Although extensive investigation has been done to understand Sjögren's syndrome, the causes of the disease are as yet unknown and treatments remain largely ineffective, with established therapeutic interventions being limited to use of saliva substitutes with modest effectiveness. A primary feature of Sjögren's syndrome is uncontrolled inflammation of exocrine tissues and previous studies have demonstrated that lipid-based specialized pro-resolving mediators reduce inflammation and restores tissue integrity in salivary glands. However, these studies are limited to a single specialized pro-resolving lipid mediator's family member resolvin D1 or RvD1 and its aspirin-triggered epimer, AT-RvD1. Consequently, additional studies are needed to explore the potential benefits of other members of the specialized pro-resolving lipid mediator's family and related molecules (e.g., additional resolvin subtypes as well as lipoxins, maresins and protectins). In support of this goal, the current review aims to briefly describe the range of current experimental methods to investigate the impact of specialized pro-resolving lipid mediators on Sjögren's syndrome, including both strengths and weaknesses of each approach where this information is known. With this article, the possibilities presented by specialized pro-resolving lipid mediators will be introduced to a wider audience in immunology and practical advice is given to researchers who may wish to take up this work.

Three-Dimensional Model of Sub-Plasmalemmal Ca2+ Microdomains Evoked by T Cell Receptor/CD3 Complex Stimulation

Ca²⁺ signalling plays an essential role in T cell activation, which is a key step to start an adaptive immune response. During the transition from a quiescent to a fully activated state, Ca²⁺ microdomains of reduced spatial and temporal extents develop in the junctions between the plasma membrane and the endoplasmic reticulum (ER). These microdomains rely on Ca²⁺ entry from the extracellular medium, via the ORAI1/STIM1/STIM2 system that mediates store operated Ca²⁺ entry Store operated calcium entry. The mechanism leading to local store depletion and subsequent Ca²⁺ entry depends on the activation state of the cells. The initial, smaller microdomains are triggered by D-myo-inositol 1,4,5-trisphosphate (IP₃) signalling in response to T cell adhesion. T cell receptor (TCR)/CD3 stimulation then initiates nicotinic acid adenine dinucleotide phosphate signalling, which activates ryanodine receptors (RYR). We have recently developed a mathematical model to elucidate the spatiotemporal Ca²⁺ dynamics of the microdomains triggered by IP₃ signalling in response to T cell adhesion (Gil et al., 2021). This reaction-diffusion model describes the evolution of the cytosolic and endoplasmic reticulum Ca²⁺ concentrations in a three-dimensional ER-PM junction and was solved using COMSOL Multiphysics. Modelling predicted that adhesion-dependent microdomains result from the concerted activity of IP₃ receptors and pre-formed ORAI1-STIM2 complexes. In the present study, we extend this model to include the role of RYRs rapidly after TCR/CD3 stimulation. The involvement of STIM1, which has a lower K_D for Ca²⁺ than STIM2, is also considered. Detailed 3D spatio-temporal simulations show that these Ca²⁺ microdomains rely on the concerted opening of ∼7 RYRs that are simultaneously active in response to the increase in NAADP induced by T cell stimulation. Opening of these RYRs provoke a local depletion of ER Ca²⁺ that triggers Ca²⁺ flux through the ORAI1 channels. Simulations predict that RYRs are most probably located around the junction and that the increase in junctional Ca²⁺ concentration results from the combination between diffusion of Ca²⁺ released through the RYRs and Ca²⁺ entry through ORAI1 in the junction. The computational model moreover provides a tool allowing to investigate how Ca²⁺ microdomains occur, extend and interact in various states of T cell activation.

Three-Dimensional Model of Sub-Plasmalemmal Ca2+ Microdomains Evoked by the Interplay Between ORAI1 and InsP3 Receptors

Ca²⁺ signaling plays an essential role in T cell activation, which is a key step to start an adaptive immune response. During the transition from a quiescent to a fully activated state, Ca²⁺ microdomains characterized by reduced spatial and temporal extents are observed in the junctions between the plasma membrane (PM) and the endoplasmic reticulum (ER). Such Ca²⁺ responses can also occur in response to T cell adhesion to other cells or extracellular matrix proteins in otherwise unstimulated T cells. These non-TCR/CD3-dependent Ca²⁺ microdomains rely on d-myo-inositol 1,4,5-trisphosphate (IP₃) signaling and subsequent store operated Ca²⁺ entry (SOCE) via the ORAI/STIM system. The detailed molecular mechanism of adhesion-dependent Ca²⁺ microdomain formation remains to be fully elucidated. We used mathematical modeling to investigate the spatiotemporal characteristics of T cell Ca²⁺ microdomains and their molecular regulators. We developed a reaction-diffusion model using COMSOL Multiphysics to describe the evolution of cytosolic and ER Ca²⁺ concentrations in a three-dimensional ER-PM junction. Equations are based on a previously proposed realistic description of the junction, which is extended to take into account IP₃ receptors (IP₃R) that are located next to the junction. The first model only considered the ORAI channels and the SERCA pumps. Taking into account the existence of preformed clusters of ORAI1 and STIM2, ORAI1 slightly opens in conditions of a full ER. These simulated Ca²⁺ microdomains are too small as compared to those observed in unstimulated T cells. When considering the opening of the IP₃Rs located near the junction, the local depletion of ER Ca²⁺ allows for larger Ca²⁺ fluxes through the ORAI1 channels and hence larger local Ca²⁺ concentrations. Computational results moreover show that Ca²⁺ diffusion in the ER has a major impact on the Ca²⁺ changes in the junction, by affecting the local Ca²⁺ gradients in the sub-PM ER. Besides pointing out the likely involvement of the spontaneous openings of IP₃Rs in the activation of SOCE in conditions of T cell adhesion prior to full activation, the model provides a tool to investigate how Ca²⁺ microdomains extent and interact in response to T cell receptor activation.

Molecular mechanisms underlying T cell co-potentiation by anti-CD3 Fab fragments

Cognate antigen binding to the T cell receptor (TCR) induces a conformational change of the CD3 complex (CD3Δc), which is required but not sufficient to trigger productive signaling from the TCR/CD3. CD3Δc fails to occur when the TCR ligates poorly immunogenic antigens. In the absence of CD3Δc, T cells do not display productive immune responses. CD3Δc involves the exposure of a conserved proline-rich-sequence (PRS) in CD3ɛ cytoplasmic tail that functions as a docking site for cytoplasmic adaptor proteins like Nck, which participate in the CD3 signaling cascade. The opening of the PRS is controlled by a CXXC motif in CD3ɛ located adjacent to the plasma membrane. We previously described it is possible to mimic CD3Δc on T cells when adding Fab fragments capable to bind to the CD3 complex. When combining TCR engagement to weak antigens with binding of Fabs to the CD3 complex that not interfere with antigen binding, T cell co-potentiation occurs. In this instance, T cells become capable to display responses to poorly immunogenic stimulation. As an example of the consequences of T cell co-potentiation in vivo, we studied anti-mouse CD3 Fabs as a novel immunotherapeutic against poorly immunogenic types of cancer. Anti-CD3 Fabs reduced melanoma burden in B6 mice bearing B16-F10 tumor in lungs. Now, we have explored the molecular mechanisms supporting T cell co-potentiation in monoclonal and polyclonal mouse models. In B6 mice expressing null mutations for either the CXXC or the PRS motifs, anti-CD3 Fabs fail to induce CD3Δc, as well as to co-potentiate murine T cells in vitro and in vivo. These data suggest PRS opening by anti-CD3 Fabs may be linked to their capacity to co-potentiate T cells responses to poorly immunogenic antigens.

The early proximal αβ TCR signalosome specifies thymic selection outcome through a quantitative protein interaction network

During αβ T cell development, T cell antigen receptor (TCR) engagement transduces biochemical signals through a protein-protein interaction (PPI) network that dictates dichotomous cell fate decisions. It remains unclear how signal specificity is communicated, instructing either positive selection to advance cell differentiation or death by negative selection. Early signal discrimination might occur by PPI signatures differing qualitatively (customized, unique PPI combinations for each signal), quantitatively (graded amounts of a single PPI series), or kinetically (speed of PPI pathway progression). Using a novel PPI network analysis, we found that early TCR-proximal signals distinguishing positive from negative selection appeared to be primarily quantitative in nature. Furthermore, the signal intensity of this PPI network was used to find an antigen dose that caused a classic negative selection ligand to induce positive selection of conventional αβ T cells, suggesting that the quantity of TCR triggering was sufficient to program selection outcome. Because previous work had suggested that positive selection might involve a qualitatively unique signal through CD3δ, we reexamined the block in positive selection observed in CD3δ⁰ mice. We found that CD3δ⁰ thymocytes were inhibited but capable of signaling positive selection, generating low numbers of MHC-dependent αβ T cells that expressed diverse TCR repertoires and participated in immune responses against infection. We conclude that the major role for CD3δ in positive selection is to quantitatively boost the signal for maximal generation of αβ T cells. Together, these data indicate that a quantitative network signaling mechanism through the early proximal TCR signalosome determines thymic selection outcome.

Abstract B78: Co-potentiation of human T cells to identify subdominant tumor neoantigens from melanoma patients responding to immune checkpoint blockade

Malignant melanoma is the most aggressive form of skin cancer, accounting for 10,000 deaths annually. Largely resistant to conventional cytotoxic chemotherapy and radiation, immune checkpoint blockade (ICB) therapies have revolutionized patient care, accounting for partial or complete responses in up to 70% of patients. An important aspect of cancer elimination is activation of the cytotoxic T lymphocyte (CTL) response. Recent data suggest that ICB mediated broadening of the peripheral blood CTL repertoire correlates with good clinical outcomes. Thus, recent studies in cancer immunotherapy have focused on targeting tumor neoantigens (tNeoAg) with cancer vaccines for use in combination with ICB. Computational algorithm-driven predictions of immunogenic tNeoAgs yield vast numbers of potential peptide targets, only a fraction of which may be immunogenic in patients. This likely contributed to the modest success of cancer vaccines targeting predicted, high-avidity tNeoAgs, emphasizing the importance of identifying true tumor rejection antigens, including sub-dominant antigens, outside the scope of predictive models. In addition to promoting T cell-mediated tumor rejection, ICB often comes at the expense of treatment-induced immune-related adverse effects (irAE) that frequently require discontinuation of treatment. Modulation of ICB towards antitumor immunity and away from autoimmunity may dramatically improve the therapeutic index of modern cancer therapy. This appears feasible considering the clinical observation that antitumor efficacy does not correlate with type/severity of irAE, suggesting that the mechanisms of both processes, though likely related (CTL mediated), may not be identical. We aim to identify and separate non-cross-reacting antigenic targets mediating tumor rejection from those mediating irAEs to enable therapeutic interventions that maximize the efficacy of ICB, expanding tumor-specific CTLs with vaccines while minimizing irAEs through desensitization. We have access to samples from responding/nonresponding melanoma patients subjected to ICB with varying degrees of irAEs. We have designed an experimental approach that combines established mass spectrometry and sequencing techniques to identify peptides and matching TCR clones with a novel strategy that targets the TCR-associated CD3 complex to allow inclusion of subdominant antigens in our studies. T-cell “co-potentiation” is achieved when anti-CD3 monovalent Fabs induce a conformational change in the CD3 complex that sustains the T-cell response to weak antigenic stimulation. We have successfully used anti-human CD3 Fabs to co-potentiate in vitro the activation and subsequent response to weak peptide-HLA/TCR interactions of human T cells found in PBMCs isolated from healthy donors. Our preliminary data suggest T-cell co-potentiation may allow identification of ICB-induced CTL clones specific for subdominant tNeoAgs and irAE targets in patients with melanoma undergoing active immunotherapy.

Citation Format: Laura Elsbernd, Alfreda Nelson, Hien Huynh, Michele Hoffmann, Christopher Parks, Wendy Nevala, Shari Sutor, Larry Pease, Adam Schrum, Diana Gil, Svetomir N. Markovic. Co-potentiation of human T cells to identify subdominant tumor neoantigens from melanoma patients responding to immune checkpoint blockade [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B78.

Anti-inflammatory coating of hernia repair meshes: a 5-rabbit study

PURPOSE

Polymeric mesh implantation has become the golden standard in hernia repair, which nowadays is one of the most frequently performed surgeries in the world. However, many biocompatibility issues remain to be a concern for hernioplasty, with chronic pain being the most notable post-operative complication. Oxidative stress appears to be a major factor in the development of those complications. Lack of material inertness in vivo and oxidative environment formed by inflammatory cells result in both mesh deterioration and slowed healing process. In a pilot in vivo study, we prepared and characterized polypropylene hernia meshes with vitamin E (α-tocopherol)-a potent antioxidant. The results of that study supported the use of vitamin E as potential coating to alleviate post-surgical inflammation, but the pilot nature of the study yielded limited statistical data. The purpose of this study was to verify the observed trend of the pilot study statistically.

METHODS

In this work, we conducted a 5-animal experiment where we have implanted vitamin E-coated and uncoated control meshes into the abdominal walls of rabbits. Histology of the mesh-adjacent tissues and electron microscopy of the explanted mesh surface were conducted to characterize host tissue response to the implanted meshes.

RESULTS

As expected, modified meshes exhibited reduced foreign body reaction, as evidenced by histological scores for fatty infiltrates, macrophages, neovascularization, and collagen organization, as well as by the surface deterioration of the meshes.

CONCLUSION

In conclusion, results indicate that vitamin E coating reduces inflammatory response following hernioplasty and protects mesh material from oxidative deterioration.

Abstract P1-02-01: Improvement of breast cancer screening access and quality in an underserved population through system interventions

Background: Differences in access to and quality of screening and treatment are proposed to contribute to racial disparities in breast cancer outcomes. Interventions designed to improve mammography access and quality encompass strategies at the individual patient, healthcare provider, and system levels. In 2016, an urban safety net healthcare system based in Chicago implemented several changes in response to collected data showing variations in quality at institutions performing mammography. These changes included the installation of digital machines at one of four sites, centralizing reading of images from all four sites to a single site with radiologists specialized in mammography and increasing care coordination including enhanced patient outreach efforts. We examined the impact of these systems-based interventions on the access to and quality of mammography services.

Methods: Data was obtained on 15,918 screening mammograms performed across four mammography centers within the Cook County Health & Hospitals System from the six months prior to and one year after implementation of changes. Manual chart abstraction was performed for each study that was assessed as BIRADS 0 (Breast Imaging and Reporting Data System), meaning an incomplete study requiring additional imaging evaluation, or mammograms that appeared suspicious or highly suspicious and categorized as BIRADS 4 or 5. Screening mammogram volume at each site was recorded and compared. Quality of screening mammograms was assessed using eleven metrics reflecting radiologist performance and efficiency of facility care processes. These metrics included the rate of recall, cancer detection rate, proportion of cancers that were early stage or minimal in size, proportion of women with timely follow-up imaging and biopsy, and rates of loss to follow-up.

Results: The volume of screening mammograms completed at each of the four sites increased from the six months prior to intervention to the six months after (range of 61-322% increase). At one-year post intervention, there were smaller, but sustained increases in volume (range of 12-70% increase). Improvements were seen in at least one quality metric at each site in the post-intervention period (range 1-8). The proportion of women with timely follow-up after abnormal mammogram also improved across all four sites: from 38% getting follow-up imaging within 30 days pre-intervention to 68% after, and from 62% to 75% of women with biopsy completion within 60 days. Rate of cancer detection improved at two of the sites with the lowest pre-intervention values, from 1.7 to 3.1 and 2.8 to 5.7 per 1,000 mammograms (quality benchmark: 3-10/1,000 screening tests).

Conclusion: Improvements in access to and quality of screening mammography demonstrate the value of implementing system level changes in enhancing breast cancer care and may translate to better outcomes for all women.

Citation Format: Manst DJ, Gil D, Marcus EA, Mullarkey P, Ganschow PS. Improvement of breast cancer screening access and quality in an underserved population through system interventions [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-02-01.

IL-12 Signals through the TCR To Support CD8 Innate Immune Responses

CD8 T cells must integrate antigenic and inflammatory signals to differentiate into efficient effector and memory T cells able to protect us from infections. The mechanisms by which TCR signaling and proinflammatory cytokine receptor signaling cooperate in these processes are poorly defined. In this study, we show that IL-12 and other proinflammatory cytokines transduce signals through the TCR signalosome in a manner that requires Fyn activity and self-peptide-MHC (self-pMHC) interactions. This mechanism is crucial for CD8 innate T cell functions. Loss of Fyn activity or blockade of self-pMHC interactions severely impaired CD8 T cell IFN-γ and NKG2D expression, proliferation, and cytotoxicity upon cytokine-mediated bystander activation. Most importantly, in the absence of self-pMHC interactions, CD8 memory T cells fail to undergo bystander activation upon an unrelated infection. Thus, CD8 T cell bystander activation, although independent of cognate Ag, still requires self-pMHC and TCR signaling.

Multiplex matrix network analysis of protein complexes in the human TCR signalosome

Multiprotein complexes transduce cellular signals through extensive interaction networks, but the ability to analyze these networks in cells from small clinical biopsies is limited. To address this, we applied an adaptable multiplex matrix system to physiologically relevant signaling protein complexes isolated from a cell line or from human patient samples. Focusing on the proximal T cell receptor (TCR) signalosome, we assessed 210 pairs of PiSCES (proteins in shared complexes detected by exposed surface epitopes). Upon stimulation of Jurkat cells with superantigen-loaded antigen-presenting cells, this system produced high-dimensional data that enabled visualization of network activity. A comprehensive analysis platform generated PiSCES biosignatures by applying unsupervised hierarchical clustering, principal component analysis, an adaptive nonparametric with empirical cutoff analysis, and weighted correlation network analysis. We generated PiSCES biosignatures from 4-mm skin punch biopsies from control patients or patients with the autoimmune skin disease alopecia areata. This analysis distinguished disease patients from the controls, detected enhanced basal TCR signaling in the autoimmune patients, and identified a potential signaling network signature that may be indicative of disease. Thus, generation of PiSCES biosignatures represents an approach that can provide information about the activity of protein signaling networks in samples including low-abundance primary cells from clinical biopsies.

Maternal IL-6 can cause T-cell-mediated juvenile alopecia by non-scarring follicular dystrophy in mice

Aiming to decipher immunological mechanisms of the autoimmune disorder alopecia areata (AA), we hypothesized that interleukin-6 (IL-6) might be associated with juvenile-onset AA, for which there is currently no experimental model. Upon intramuscular transgenesis to overexpress IL-6 in pregnant female C57BL/6 (B6) mice, we found that the offspring displayed an initial normal and complete juvenile hair growth cycle, but developed alopecia around postnatal day 18. This alopecia was patchy and reversible (non-scarring) and was associated with upregulation of Ulbp1 expression, the only mouse homolog of the human AA-associated ULBP3 gene. Alopecia was also associated with inflammatory infiltration of hair follicles by lymphocytes, including alpha-beta T cells, which contributed to surface hair loss. Despite these apparently shared traits with AA, lesions were dominated by follicular dystrophy that was atypical of human AA disease, sharing some traits consistent with B6 alopecia and dermatitis. Additionally, juvenile-onset alopecia was followed by complete, spontaneous recovery of surface hair, without recurrence of hair loss. Prolonging exposure to IL-6 prolonged the time to recovery, but once recovered, repeating high-dose IL-6 exposure de novo did not re-induce alopecia. These data suggest that although substantial molecular and cellular pathways may be shared, functionally similar alopecia disorders can occur via distinct pathological mechanisms.

Co-potentiation of antigen recognition: A mechanism to boost weak T cell responses and provide immunotherapy in vivo

Adaptive immunity is mediated by antigen receptors that can induce weak or strong immune responses depending on the nature of the antigen that is bound. In T lymphocytes, antigen recognition triggers signal transduction by clustering T cell receptor (TCR)/CD3 multiprotein complexes. In addition, it hypothesized that biophysical changes induced in TCR/CD3 that accompany receptor engagement may contribute to signal intensity. Nonclustering monovalent TCR/CD3 engagement is functionally inert despite the fact that it may induce changes in conformational arrangement or in the flexibility of receptor subunits. We report that the intrinsically inert monovalent engagement of TCR/CD3 can specifically enhance physiologic T cell responses to weak antigens in vitro and in vivo without stimulating antigen-unengaged T cells and without interrupting T cell responses to strong antigens, an effect that we term as "co-potentiation." We identified Mono-7D6-Fab, which biophysically altered TCR/CD3 when bound and functionally enhanced immune reactivity to several weak antigens in vitro, including a gp100-derived peptide associated with melanoma. In vivo, Mono-7D6-Fab induced T cell antigen-dependent therapeutic responses against melanoma lung metastases, an effect that synergized with other anti-melanoma immunotherapies to significantly improve outcome and survival. We conclude that Mono-7D6-Fab directly co-potentiated TCR/CD3 engagement by weak antigens and that such concept can be translated into an immunotherapeutic design. The co-potentiation principle may be applicable to other receptors that could be regulated by otherwise inert compounds whose latent potency is only invoked in concert with specific physiologic ligands.

A Versatile Simple Capture Assay for Assessing the Structural Integrity of MHC Multimer Reagents

Antigen-specific T cell responses can be visualized using MHC:peptide multimers. In cases where robust T cell controls are not readily available to assess the integrity of multimer reagents prior to analyzing limited sample, the ability to assess the structural integrity of MHC multimers before their use in critical experiments would be useful. We present a method to probe the structural integrity of MHC multimers using antibodies specific for conformational determinants. Beads coated with anti-mouse Ig are incubated with conformation-specific mouse monoclonal antibody and then with fluorescently tagged MHC multimer. The ability of the bead to capture the labeled multimer can be measured semi-quantitatively by flow cytometry. In this manner, the correct folding of MHC multimers can be visualized and batches of multimer can be compared for quality control. Because there are multiple conformational epitopes formed by various molecular interactions among heavy chain, peptide, and β₂M, this capture assay can assess the fidelity of each aspect of multimer structure, depending on the availability of antibodies. The described approach could be particularly useful for studies using irreplaceable samples, including patient samples collected in clinical trials.

Context-dependent effects of yolk androgens on nestling growth and immune function in a multibrooded passerine

Female birds may adjust their offspring phenotype to the specific requirements of the environment by differential allocation of physiologically active substances into yolks, such as androgens. Yolk androgens have been shown to accelerate embryonic development, growth rate and competitive ability of nestlings, but they can also entail immunological costs. The balance between costs and benefits of androgen allocation is expected to depend on nestling environment. We tested this hypothesis in a multibrooded passerine, the spotless starling, Sturnus unicolor. We experimentally manipulated yolk androgen levels using a between-brood design and evaluated its effects on nestling development, survival and immune function. Both in first and replacement broods, the embryonic development period was shorter for androgen-treated chicks than controls, but there were no differences in second broods. In replacement broods, androgen-treated chicks were heavier and larger than those hatched from control eggs, but this effect was not observed in the other breeding attempts. Androgen exposure reduced survival with respect to controls only in second broods. Regarding immune function, we detected nonsignificant trends for androgen treatment to activate two important components of innate and adaptive immunity (IL-6 and Ig-A levels, respectively). Similarly, androgen-treated chicks showed greater lymphocyte proliferation than controls in the first brood and an opposite trend in the second brood. Our results indicate that yolk androgen effects on nestling development and immunity depend on the environmental conditions of each breeding attempt. Variation in maternal androgen allocation to eggs could be explained as the result of context-dependent optimal strategies to maximize offspring fitness.

Signalling protein complexes isolated from primary human skin-resident T cells can be analysed by Multiplex IP-FCM

Studying signal transduction in skin-resident T cells (sr-T cells) can be limited by the small size of clinical biopsies. Here, we isolated sr-T cells from clinical samples and analysed signalling protein complexes by multiplex immunoprecipitation detected by flow cytometry (mIP-FCM). In samples from two independent donors, antigenic stimulation induced signalling proteins to join shared complexes that were observed in seven pairwise combinations among five proteins. This demonstrates that sr-T cells isolated from small clinical samples provide sufficient material for mIP-FCM-based analysis of signalling-induced protein complexes. We propose that this strategy may be useful for gaining improved mechanistic insight of sr-T cell signal transduction associated with dermatological disease.

Detection of constant domain of human T cell antigen receptor alpha-chain via novel monoclonal antibody 7F18

The αβ T cell antigen receptor (TCR) endows T lymphocytes with immune specificity and controls their effector functions. Each person possesses a vast repertoire of TCRs that is generated by the well-studied processes of somatic recombination and thymic selection. While many antibodies specific for TCRβ variable domains are available, antibodies specific for human TCRα are rare. We now report a novel monoclonal antibody, 7F18, which binds to human TCRα constant region, with specificity for a denatured epitope that can be visualized by SDS-PAGE followed by Western blot. Both immature and mature TCR α-chain products can be visualized, making 7F18 potentially applicable to various biochemical assays of multiprotein complex assembly and maturation. This new monoclonal antibody provides a tool that can potentially facilitate the biochemical analysis of comprehensive populations of human αβ TCR complexes that need not be limited to small subsets of the repertoire.

[Scapular balance angle reference values in a healthy population]

OBJECTIVES

To calculate the Scapular Balance Angle (SBA) reference values in a healthy population between 18 and 85 years old, and to define abnormality criteria for this sample.

MATERIALS AND METHODS

A descriptive study was conducted on a total of 300 individuals (mean age: 44.83, range: 18-83; proportion male/female: 1.59), calculating the SBA through manual measurement with a goniometer. An intraobserver Intraclass Correlation Coefficient (ICC) of 0.87 and a interobserver ICC of 0.84 was observed.

RESULTS

The values for the SBA in healthy population were 2.505 ± 2.340°. We define the abnormality criteria for this sample with an angle greater than 7.185°.

DISCUSSION

SBA manual measurement is a simple and reproducible assessment of the position and rotation of the scapula in clinical practice. The main findings of this study are the reference values for the SBA and a statistical cut-off to define abnormality.

Toward T cell protein-protein interaction activity relevant to alopecia areata

Development of better therapies for the T cell-mediated autoimmune disease alopecia areata (AA) could be expedited by an improved understanding of the immunologic signals underlying its pathogenesis. To approach this, our group is mounting a new technological and analytical platform, multiplex immunoprecipitation detected by flow cytometry (MIF). MIF is designed to allow analysis of collections of protein-protein interactions that participate in T cell signaling webs. Early experiments suggest that MIF can detect the increased protein-protein interaction network activity that occurs under conditions of T cell antigenic stimulation. Future experiments will focus on application of MIF to T cells isolated from AA or control patient samples, to identify critical T cell signaling complexes associated with the disorder.

A PCR-Based Method to Genotype Mice Knocked Out for All Four CD3 Subunits, the Standard Recipient Strain for Retrogenic TCR/CD3 Bone Marrow Reconstitution Technology

The novel T-cell receptor (TCR)/CD3-retrogenic-reconstitution system represents a very useful strategy for studying TCR/CD3 signaling. Two retroviral vectors containing genes for all six subunits of the TCR/CD3 complex are used to transduce bone marrow precursors and reconstitute lethally irradiated recipient mice. Mice used in this system as bone marrow donors lack all four CD3 subunits (CD3γδɛζ^−/−). These mice are generated by crossing the strains CD3ζ^−/− and CD3γδɛ^−/−, the latter resulting from a knockout construct targeted to CD3ɛ that additionally silences the linked genes, CD3γ and CD3δ. Lacking mature T-cell function, CD3γδɛζ^−/− mice are immunocompromised animals often produced by heterozygous breeding strategies on the C57BL/6 background. As a more rapid and reliable means to identify CD3γδɛζ^−/− mice than previously described Northern and Southern blots, we designed polymerase chain reactions to distinguish knockout from wild-type CD3ɛ and CD3ζ alleles, facilitating the identification of CD3γδɛζ^−/− mice.

A co-housing strategy to improve fecundity of mice in timed matings

Timed matings of mice are often carried out to obtain offspring of a precise age when required for a study. Timed matings involve housing male and female mice together for a limited time period, typically overnight. A limitation of this practice is that many mouse pairs fail to mate during the brief co-housing period. The authors co-housed each breeding pair in the same cage but separated by a transparent partition for 3 d before carrying out timed matings. This co-housing strategy resulted in increased copulation during the timed mating period and also significantly increased the average number of pups produced per breeding pair. The authors suggest that co-housing likely permits male urine-borne pheromones to induce female estrus and also enables the expression of male and female mating behaviors.

Strategies to stabilize compact folding and minimize aggregation of antibody-based fragments

Monoclonal antibodies (mAbs) have proven to be useful for development of new therapeutic drugs and diagnostic techniques. To overcome the difficulties posed by their complex structure and folding, reduce undesired immunogenicity, and improve pharmacokinetic properties, a plethora of different Ab fragments have been developed. These include recombinant Fab and Fv segments that can display improved properties over those of the original mAbs upon which they are based. Antibody (Ab) fragments such as Fabs, scFvs, diabodies, and nanobodies, all contain the variable Ig domains responsible for binding to specific antigenic epitopes, allowing for specific targeting of pathological cells and/or molecules. These fragments can be easier to produce, purify and refold than a full Ab, and due to their smaller size they can be well absorbed and distributed into target tissues. However, the physicochemical and structural properties of the immunoglobulin (Ig) domain, upon which the folding and conformation of all these Ab fragments is based, can limit the stability of Ab-based drugs. The Ig domain is fairly sensitive to unfolding and aggregation when produced out of the structural context of an intact Ab molecule. When unfolded, Ab fragments may lose their specificity as well as establish non-native interactions leading to protein aggregation. Aggregated antibody fragments display altered pharmacokinetic and immunogenic properties that can augment their toxicity. Therefore, much effort has been placed in understanding the factors impacting the stability of Ig folding at two different levels: 1) intrinsically, by studying the effects of the amino acid sequence on Ig folding; 2) extrinsically, by determining the environmental conditions that may influence the stability of Ig folding. In this review we will describe the structure of the Ig domain, and the factors that impact its stability, to set the context for the different approaches currently used to achieve stable recombinant Ig domains when pursuing the development of Ab fragment-based biotechnologies.

Robustness and Specificity in Signal Transduction via Physiologic Protein Interaction Networks

The collective Protein:Protein Interactions (PPI) of a cell are thought to represent a system with emergent network properties that integrate signals from a multiplicity of inputs into coordinated responses. It is hypothesized that the PPI network supplies both specificity for many distinct signals that utilize common intermediate pathways, and also robustness by allowing specific signals to be communicated by alternate routes. Progress with genetic networks points to these concepts, but the extent to which PPI networks possess these properties has not been empirically tested, due to lack of quantitative data needed for such assessments. Here, a hypothetical physiologic PPI network is used to illustrate how signaling robustness and specificity could be manifest under conditions of (i) deletion mutation, or (ii) changes in signaling due to variation in environmental conditions or stimuli. It is proposed that advances in technology enabling empirical analysis of PPI network principles will have the potential to significantly impact basic understanding of signaling mechanisms, and contribute to the generation of novel applications in drug screening and pharmacology.

IgG Fab fragments forming bivalent complexes by a conformational mechanism that is reversible by osmolytes

Generated by proteolytic cleavage of immunoglobulin, Fab fragments possess great promise as blocking reagents, able to bind receptors or other targets without inducing cross-linking. However, aggregation of Fab preparations is a common occurrence, which generates intrinsic stimulatory capacity and thwarts signal blockade strategies. Using a panel of biochemical approaches, including size exclusion chromatography, SDS-PAGE, mass spectrometry, and cell stimulation followed by flow cytometry, we have measured the oligomerization and acquisition of stimulatory capacity that occurs in four monoclonal IgG Fabs specific for TCR/CD3. Unexpectedly, we observed that all Fabs spontaneously formed complexes that were precisely bivalent, and these bivalent complexes possessed most of the stimulatory activity of each Fab preparation. Fabs composing bivalent complexes were more susceptible to proteolysis than monovalent Fabs, indicating a difference in conformation between the Fabs involved in these two different states of valency. Because osmolytes represent a class of compounds that stabilize protein folding and conformation, we sought to determine the extent to which the amino acid osmolyte l-proline might impact bivalent Fab complexation. We found that l-proline (i) inhibited the adoption of the conformation associated with bivalent complexation, (ii) preserved Fab monovalency, (iii) reversed the conformation of preformed bivalent Fabs to that of monovalent Fabs, and (iv) separated a significant percentage of preformed bivalent complexes into monovalent species. Thus, Fab fragments can adopt a conformation that is compatible with folding or packing of a bivalent complex in a process that can be inhibited by osmolytes.

End-binding protein 1 controls signal propagation from the T cell receptor

The role of microtubules (MTs) in the control and dynamics of the immune synapse (IS) remains unresolved. Here, we show that T cell activation requires the growth of MTs mediated by the plus-end specific protein end-binding 1 (EB1). A direct interaction of the T cell receptor (TCR) complex with EB1 provides the molecular basis for EB1 activity promoting TCR encounter with signalling vesicles at the IS. EB1 knockdown alters TCR dynamics at the IS and prevents propagation of the TCR activation signal to LAT, thus inhibiting activation of PLCγ1 and its localization to the IS. These results identify a role for EB1 interaction with the TCR in controlling TCR sorting and its connection with the LAT/PLCγ1 signalosome.

The inhibition of cell proliferation using silencing of N-cadherin gene by siRNA process in human melanoma cell lines

Malignant melanoma is a disease with high mortality rate caused by rapid metastasis. Cell motility is physically and biochemically restricted by cadherin-mediated cell interactions and signalling pathways, and alterations in cadherin expression strongly correlate with E to N-cadherin switch as well as the metastasis and progression of tumours. Contrary to E-cadherin, N-cadherin plays an important role in stimulating processes of cell division, migration, differentiation and death. In this study we investigated the role of N-cadherin in proliferation and AKT, ERK, beta-catenin signalling pathway in human melanoma cells: WM793(VGP), WM115(VGP) from the primary tumor site, as well as Lu1205(lung) and WM266-4(skin) from metastatic sites. N-cadherin, pAKT(S473), β-catenin, pERK1/2(T202/Y204), cyclin D1, cyclin D3, cyclin-dependent kinases CDK4, CDK6, and p15, p16, p21, p27 inhibitors expression was determined by western blot analysis. The study on proliferation of cells was performed with the use of BrdU incorporation and crystal violet staining assays. Knock-out of N-cadherin gene expression by siRNA process reduced the expression of: pAKT(S473), pERK1/2(T202/Y204), betacatenin, cyclin D1, cyclin D3, cyclin-dependent kinases CDK4, CDK6 while increasing expression of cell cycle inhibitors p21 and p27, and significantly decreased cell proliferation (50-70%). The collected data indicate that N-cadherin mediates the effect of cell cycle in G1 phase by AKT, β-catenin, and ERK signalling pathway. These results suggest that increased expression of N-cadherin significantly contributes to the increased invasive potential of melanoma cells. Silencing of N-cadherin arrests cell growth at G1 phase and inhibits the entry into S-phase which is of great importance as to its possible future use in cancer treatment.

Comparison of three predictive rules for assessing severity in elderly patients with CAP

AIM

This study compares the ability of the Pneumonia Severity Index (PSI) and the British Thoracic Society CURB-65 and CRB-65 rules in predicting short-term mortality among elderly patients with community-acquired pneumonia (CAP).

METHODS

It is a population-based study including all people over 65 years old with a radiographically confirmed CAP in the region of Tarragona (Spain) between 2002 and 2008. Treatment setting and clinical variables were considered for each patient. PSI, CURB-65 and CRB-65 scores were calculated at the moment of diagnosis and 30-day mortality was considered as a main dependent variable. The rules were compared based on sensitivity, specificity and area under the receiver operating characteristic curve (AUC).

RESULTS

Of the total 590 CAP cases, mortality rate was 13.6% (15.3% in hospitalised and 1.4% in outpatient cases; p = 0.001). Mortality increased with increasing PSI score (None in class II, 6,9% in class III, 14,4% in class IV and 29,5% in class V), CURB-65 score (7.5%, 14.5%, 26.7%, 53.3% and 100% for scores 1,2,3,4 and 5 respectively) and CRB-65 score (6.6%, 26.1%, 40.5% and 50% for scores 1,2,3 and 4 respectively). The three rules performed too similarly to predict 30-day mortality, with a ROC area of 0.727 [95% confidence interval (CI): 0.67-0.79] for the PSI, 0.672 (95% CI: 0.61-0.74) for the CURB-65, and 0.719 (95% CI: 0.65-0.78) for the CRB-65.

CONCLUSION

Our data shows that the analysed rules perform equally well among elderly people with CAP which supports the recommendation for using the simplified CRB-65 severity score among elderly patients in primary care or emergency visits.

Multiplex IP-FCM (immunoprecipitation-flow cytometry): Principles and guidelines for assessing physiologic protein-protein interactions in multiprotein complexes

There is significant interest in the development of methods with the potential to increase access to 'the interactome' for both experimental and clinical applications. Immunoprecipitation detected by flow cytometry (IP-FCM) is a robust, biochemical method that can be used for measuring physiologic protein-protein interactions (PPI) in multiprotein complexes (MPC) with high sensitivity. Because it is based on antibody-mediated capture of protein complexes onto microspheres, IP-FCM is potentially compatible with a multiplex platform that could allow simultaneous assessment of many physiologic PPI. Here, we consider the principles of ambient analyte conditions (AAC) and inter-bead independence, and provide a template set of experiments showing how to convert singleplex IP-FCM to multiplex IP-FCM, including assays to confirm the validity of the experimental conditions for data acquisition. We conclude that singleplex IP-FCM can be successfully upgraded to multiplex format, and propose that the unique strengths of multiplex IP-FCM make it a method that is likely to facilitate the acquisition of new PPI data from primary cell sources.

Physical and functional bivalency observed among TCR/CD3 complexes isolated from primary T cells

Unlike BCR and secreted Ig, TCR expression is not thought to occur in a bivalent form. The conventional monovalent model of TCR/CD3 is supported by published studies of complexes solubilized in the detergent digitonin, in which bivalency was not observed. We revisited the issue of TCR valency by examining complexes isolated from primary αβ T cells after solubilization in digitonin. Using immunoprecipitation followed by flow cytometry, we unexpectedly observed TCR/CD3 complexes that contained two TCRs per complex. Standard anti-TCR Abs, being bivalent themselves, tended to bind with double occupancy to bivalent TCRs; this property masked the presence of the second TCR per complex in certain Ab binding assays, which may partially explain why previous data did not reveal these bivalent complexes. We also found that the prevalence of bivalency among fully assembled, mature TCR/CD3 complexes was sufficient to impact the functional performance of immunoprecipitated TCRs in binding antigenic peptide/MHC-Ig fusion proteins. Both TCR positions per bivalent complex required an Ag-specific TCR to effect optimal binding to these soluble ligands. Therefore, we conclude that in primary T cells, TCR/CD3 complexes can be found that are physically and functionally bivalent. The expression of bivalent TCR/CD3 complexes has implications regarding potential mechanisms by which Ag may trigger signaling. It also suggests the possibility that the potential for bivalent expression could represent a general feature of Ag receptors.

Basal and antigen-induced exposure of the proline-rich sequence in CD3ε

The CD3ε cytoplasmic tail contains a conserved proline-rich sequence (PRS) that influences TCR-CD3 expression and signaling. Although the PRS can bind the SH3.1 domain of the cytosolic adapter Nck, whether the PRS is constitutively available for Nck binding or instead represents a cryptic motif that is exposed via conformational change upon TCR-CD3 engagement (CD3Δc) is currently unresolved. Furthermore, the extent to which a cis-acting CD3ε basic amino acid-rich stretch (BRS), with its unique phosphoinositide-binding capability, might impact PRS accessibility is not clear. In this study, we found that freshly harvested primary thymocytes expressed low to moderate basal levels of Nck-accessible PRS ("open-CD3"), although most TCR-CD3 complexes were inaccessible to Nck ("closed-CD3"). Ag presentation in vivo induced open-CD3, accounting for half of the basal level found in thymocytes from MHC(+) mice. Additional stimulation with either anti-CD3 Abs or peptide-MHC ligands further elevated open-CD3 above basal levels, consistent with a model wherein antigenic engagement induces maximum PRS exposure. We also found that the open-CD3 conformation induced by APCs outlasted the time of ligand occupancy, marking receptors that had been engaged. Finally, CD3ε BRS-phosphoinositide interactions played no role in either adoption of the initial closed-CD3 conformation or induction of open-CD3 by Ab stimulation. Thus, a basal level of open-CD3 is succeeded by a higher, induced level upon TCR-CD3 engagement, involving CD3Δc and prolonged accessibility of the CD3ε PRS to Nck.

Determination of the total width of the η' meson

Taking advantage of both the low-emittance proton beam of the cooler synchrotron COSY and the high momentum precision of the COSY-11 detector system, the mass distribution of the η' meson was measured with a resolution of 0.33  MeV/c2 (FWHM), improving the experimental mass resolution by almost an order of magnitude with respect to previous results. Based on the sample of more than 2300 reconstructed pp → ppη' events, the total width of the η' meson was determined to be Γ(η') = 0.226 ± 0.017(stat) ± 0.014(syst)  MeV/c2.

A normalized framework for the design of feature spaces assessing the left ventricular function

A through description of the left ventricle functionality requires combining complementary regional scores. A main limitation is the lack of multiparametric normality models oriented to the assessment of regional wall motion abnormalities (RWMA). This paper covers two main topics involved in RWMA assessment. We propose a general framework allowing the fusion and comparison across subjects of different regional scores. Our framework is used to explore which combination of regional scores (including 2-D motion and strains) is better suited for RWMA detection. Our statistical analysis indicates that for a proper (within interobserver variability) identification of RWMA, models should consider motion and extreme strains.

CD3 molecules in a conformational equilibrium that is altered by TCR engagement (35.41)

Previously we and others observed that the signaling module of the TCR, the CD3 complex, undergoes a conformational change at the level of its cytoplasmic tails when T cells are stimulated. At that time, we interpreted this data as proof that antigen recognition modifies the conformation of CD3 as part of the receptor triggering mechanism. In absence of specific structural information, the induced conformation has been referred to as "open CD3". Here we present new evidence that thymocytes display detectable amounts of "open CD3" even in the absence of antigenic stimulation. However, treatment of thymocytes with stimulatory anti-CD3 antibodies significantly increases the amount of "open CD3". We conclude that ligand binding causes many CD3 molecules to adopt the "open CD3" conformation. We propose that CD3 is expressed in an equilibrium between two distinguishable conformations, which may reflect "on" and "off" states that are perturbed by TCR engagement. The accumulation of a certain level of "open CD3" might trigger T cell activation.

Research support: Diana Gil, Travis Kruger and Javier de la Cruz were supported with start-up funds from the Mayo Foundation.

Use of Barcelona Test for cognitive assessment of patients with schizophrenia

INTRODUCTION

In recent years different neuropsychological batteries have been developed to assess cognitive performance in schizophrenia. However, no test has been validated in Spanish for this purpose. The Barcelona Test has been one of the tests used. This present article has aimed to present a specific neurocognitive battery for schizophrenia by selecting specific subtests from the Barcelona Test. Normative data for patients with schizophrenia are presented and the influence of a number of variables is taken into account.

METHODS

The sample included 209 patients. The relationship between cognitive performance and gender, age, educational level, age of onset, duration of illness and symptomatology were assessed. Symptomatology was collected with the Positive and Negative Syndrome Scale for Schizophrenia.

RESULTS

More of the 50% of the sample had cognitive impairment when compared with standardized percentile scores of the Barcelona Test. No significant relationships between cognitive performance and variables assessed were found, except for in the educational level. Thus, percentile scores for the total sample and for the sample in terms of educational level were obtained.

CONCLUSIONS

The high percentage of patients with cognitive impairment when standardized percentile scores were used reinforces the need to use normative data appropriate for the schizophrenia group. The lack of relationship between cognitive performance and the variables assessed supports the hypothesis that cognitive impairment is a core feature in schizophrenia.

A role for CD8 in the developmental tuning of antigen recognition and CD3 conformational change

TCR engagement by peptide-MHC class I (pMHC) ligands induces a conformational change (Deltac) in CD3 (CD3Deltac) that contributes to T cell signaling. We found that when this interaction took place between primary T lineage cells and APCs, the CD8 coreceptor was required to generate CD3Deltac. Interestingly, neither enhancement of Ag binding strength nor Src kinase signaling explained this coreceptor activity. Furthermore, Ag-induced CD3Deltac was developmentally attenuated by the increase in sialylation that accompanies T cell maturation and limits CD8 activity. Thus, both weak and strong ligands induced CD3Deltac in preselection thymocytes, but only strong ligands were effective in mature T cells. We propose that CD8 participation in the TCR/pMHC interaction can physically regulate CD3Deltac induction by "translating" productive Ag encounter from the TCR to the CD3 complex. This suggests one mechanism by which the developmentally regulated variation in CD8 sialylation may contribute to the developmental tuning of T cell sensitivity.

Myocardial perfusion characterization from contrast angiography spectral distribution

Despite recovering a normal coronary flow after acute myocardial infarction, percutaneous coronary intervention does not guarantee a proper perfusion (irrigation) of the infarcted area. This damage in microcirculation integrity may detrimentally affect the patient survival. Visual assessment of the myocardium opacification in contrast angiography serves to define a subjective score of the microcirculation integrity myocardial blush analysis (MBA). Although MBA correlates with patient prognosis its visual assessment is a very difficult task that requires of a highly expertise training in order to achieve a good intraobserver and interobserver agreement. In this paper, we provide objective descriptors of the myocardium staining pattern by analyzing the spectrum of the image local statistics. The descriptors proposed discriminate among the different phenomena observed in the angiographic sequence and allow defining an objective score of the myocardial perfusion.

New Vaccines Require Potent Adjuvants like AFPL1 and AFCo1

Neisseria meningitidis B proteoliposome (AFPL1 when used as adjuvant) and its derivative-Cochleate (AFCo1) contain immunopotentiating and immunomodulating properties and delivery system capacities required for a good adjuvant. Additionally, they contain meningococcal protective antigens and permit packaging of other antigens and pathogen-associated molecular patterns (PAMP). Consequently, we hypothesized that they would function as good vaccine adjuvants for their own antigens and also for non-related antigens. AFPL1 is a detergent-extracted outer membrane vesicle of N. meningitidis B transformed into AFCo1 in calcium environment. Both are produced at Finlay Institute under good manufacture practices (GMP) conditions. We show their exceptional characteristics: combining in the same structure, the potentiator activity, polarizing agents and delivery system capacities; presenting multimeric protein copies; containing multiprotein composition and multi and synergistic PAMP components; acting with incorporated or co-administrated antigens; inducing type I IFN-gamma and IL-12 cytokines suggesting the stimulation of human plasmocytoid precursor and conventional dendritic cells, respectively, inducing a preferential Th1 immune response with TCD4(+), TCD8(+), cross-presentation and cytotoxic T-lymphocyte (CTL) in vivo responses; and functioning by parenteral and mucosal routes. AFPL1-AFCo1 protective protein constitutions permit per se their function as a vaccine. In addition to Phase IV Men BC vaccine, AFPL1 has ended the preclinical stage in an allergy vaccine and is concluding the preclinical stage of a nasal meningococcal vaccine. In conclusion, AFPL1 and AFCo1 induced signal 1, 2 and 3 polarizing to a Th1 (including CTL) response when they acted directly as vaccines or were used as adjuvants with incorporated or co-administered antigens by parenteral or mucosal routes. Both are very promising adjuvants.

Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird

Mothers can improve the quality of their offspring by increasing the level of certain components in their eggs. To examine whether or not mothers increase deposition of such components in eggs as a function of food availability, we food-supplemented black-legged kittiwake females (Rissa tridactyla) before and during egg laying and compared deposition of androgens and antibodies into eggs of first and experimentally induced replacement clutches. Food-supplemented females transferred lower amounts of androgens and antibodies into eggs of induced replacement clutches than did non-food-supplemented mothers, whereas first clutches presented no differences between treatments. Our results suggest that when females are in lower condition, they transfer more androgens and antibodies into eggs to facilitate chick development despite potential long-term costs for juveniles. Females in prime condition may avoid these potential long-term costs because they can provide their chicks with more and higher quality resources.

High-sensitivity detection and quantitative analysis of native protein-protein interactions and multiprotein complexes by flow cytometry

Most mechanisms of cell development, physiology, and signal transduction are controlled by protein-protein interactions. Immunoprecipitation of multiprotein complexes detected by flow cytometry (IP-FCM) is a means to quantitatively measure these interactions. The high sensitivity of this method makes it useful even when very little biomaterial is available for analysis, as in the case of rare primary cell subsets or patient samples. Detection of the T cell antigen receptor associated with the CD3 multiprotein complex from as few as 300 primary murine T cells is presented as an example. The method is compatible with quantitative flow cytometry techniques, making it possible to estimate the number of coimmunoprecipitated molecules. Both constitutive and inducible protein-protein interactions can be analyzed, as illustrated in related methodology using glutathione S-transferase-fusion protein pull-down experiments. IP-FCM represents a robust, quantitative, biochemical technique to assess native protein-protein interactions, without requiring genetic engineering or large sample sizes.