Microarray Analysis of Antibodies Induced with Synthetic Antitumor Vaccines: Specificity against Diverse Mucin Core Structures

Glycoprotein research is pivotal for vaccine development and biomarker discovery. Many successful methodologies for reliably increasing the antigenicity toward tumor-associated glycopeptide structures have been reported. Deeper insights into the quality and specificity of the raised polyclonal, humoral reactions are often not addressed, despite the fact that an immunological memory, which produces antibodies with cross-reactivity to epitopes exposed on healthy cells, may cause autoimmune diseases. In the current work, three MUC1 antitumor vaccine candidates conjugated with different immune stimulants are evaluated immunologically. For assessment of the influence of the immune stimulant on antibody recognition, a comprehensive library of mucin 1 glycopeptides (>100 entries) is synthesized and employed in antibody microarray profiling; these range from small tumor-associated glycans (T_N , ST_N , and T-antigen structures) to heavily extended O-glycan core structures (type-1 and type-2 elongated core 1-3 tri-, tetra-, and hexasaccharides) glycosylated in variable density at the five different sites of the MUC1 tandem repeat. This is one of the most extensive glycopeptide libraries ever made through total synthesis. On tumor cells, the core 2 β-1,6-N-acetylglucosaminyltransferase-1 (C2GlcNAcT-1) is down-regulated, resulting in lower amounts of the branched core 2 structures, which favor formation of linear core 1 or core 3 structures, and in particular, truncated tumor-associated antigen structures. The core 2 structures are commonly found on healthy cells and the elucidation of antibody cross-reactivity to such epitopes may predict the tumor-selectivity and safety of synthetic vaccines. With the extended mucin core structures in hand, antibody cross-reactivity toward the branched core 2 glycopeptide epitopes is explored. It is observed that the induced antibodies recognize MUC1 peptides with very high glycosylation site specificity. The nature of the antibody response is characteristically different for antibodies directed to glycosylation sites in either the immune-dominant PDTR or the GSTA domain. All antibody sera show high reactivity to the tumor-associated saccharide structures on MUC1. Extensive glycosylation with branched core 2 structures, typically found on healthy cells, abolishes antibody recognition of the antisera and suggests that all vaccine conjugates preferentially induce a tumor-specific humoral immune response.

Hallux valgus surgery affects kinematic parameters during gait

BACKGROUND

The aim of our study was to compare spatiotemporal parameters and lower limb and pelvis kinematics during the walking in patients with hallux valgus before and after surgery and in relation to a control group.

METHODS

Seventeen females with hallux valgus, who underwent first metatarsal osteotomy, constituted our experimental group. The control group consisted of thirteen females. Kinematic data during walking were obtained using the Vicon MX system.

FINDINGS

Our results showed that hallux valgus before surgery affects spatiotemporal parameters and lower limb and pelvis kinematics during walking. Hallux valgus surgery further increased the differences that were present before surgery. Specifically after hallux valgus surgery, the walking speed decreased even more (p=0.09, η²=0.19) while step time increased (p=0.002, η²=0.44) on both legs. The maximum ankle plantar flexion of the operated leg during toe-off decreased to a greater extend (p=0.03, η²=0.26). The asymmetry in the hip and the pelvis movements in the frontal plane (present preoperatively) persisted after surgery.

INTERPRETATION

Hallux valgus is not an isolated problem of the first ray, which could be just surgically addressed by correcting the foot's alignment. It is a long-term progressive malfunction of the foot affecting the entire kinematic chain of the lower extremity.

Aging affects postural tracking of complex visual motion cues

Postural tracking of visual motion cues improves perception-action coupling in aging, yet the nature of the visual cues to be tracked is critical for the efficacy of such a paradigm. We investigated how well healthy older (72.45 ± 4.72 years) and young (22.98 ± 2.9 years) adults can follow with their gaze and posture horizontally moving visual target cues of different degree of complexity. Participants tracked continuously for 120 s the motion of a visual target (dot) that oscillated in three different patterns: a simple periodic (simulated by a sine), a more complex (simulated by the Lorenz attractor that is deterministic displaying mathematical chaos) and an ultra-complex random (simulated by surrogating the Lorenz attractor) pattern. The degree of coupling between performance (posture and gaze) and the target motion was quantified in the spectral coherence, gain, phase and cross-approximate entropy (cross-ApEn) between signals. Sway-target coherence decreased as a function of target complexity and was lower for the older compared to the young participants when tracking the chaotic target. On the other hand, gaze-target coherence was not affected by either target complexity or age. Yet, a lower cross-ApEn value when tracking the chaotic stimulus motion revealed a more synchronous gaze-target relationship for both age groups. Results suggest limitations in online visuo-motor processing of complex motion cues and a less efficient exploitation of the body sway dynamics with age. Complex visual motion cues may provide a suitable training stimulus to improve visuo-motor integration and restore sway variability in older adults.

A Synthetic Glycopeptide Vaccine for the Induction of a Monoclonal Antibody that Differentiates between Normal and Tumor Mammary Cells and Enables the Diagnosis of Human Pancreatic Cancer

In studies within the realm of cancer immunotherapy, the synthesis of exactly specified tumor-associated glycopeptide antigens is shown to be a key strategy for obtaining a highly selective biological reagent, that is, a monoclonal antibody that completely differentiates between tumor and normal epithelial cells and specifically marks the tumor cells in pancreas tumors. Mucin MUC1, which is overexpressed in many prevalent cancers, was identified as a promising target for this strategy. Tumor-associated MUC1 differs significantly from that expressed by normal cells, in particular by altered glycosylation. Structurally defined tumor-associated MUC1 cannot be isolated from tumor cells. We synthesized MUC1-glycopeptide vaccines and analyzed their structure-activity relationships in immunizations; a monoclonal antibody that specifically distinguishes between human normal and tumor epithelial cells was thus generated.

Tick Salivary Sialostatin L Represses the Initiation of Immune Responses by Targeting IRF4-Dependent Transcription in Murine Mast Cells

Coevolution of ticks and the vertebrate immune system has led to the development of immunosuppressive molecules that prevent immediate response of skin-resident immune cells to quickly fend off the parasite. In this article, we demonstrate that the tick-derived immunosuppressor sialostatin L restrains IL-9 production by mast cells, whereas degranulation and IL-6 expression are both unaffected. In addition, the expression of IL-1β and IRF4 is strongly reduced in the presence of sialostatin L. Correspondingly, IRF4- or IL-1R-deficient mast cells exhibit a strong impairment in IL-9 production, demonstrating the importance of IRF4 and IL-1 in the regulation of the Il9 locus in mast cells. Furthermore, IRF4 binds to the promoters of Il1b and Il9, suggesting that sialostatin L suppresses mast cell-derived IL-9 preferentially by inhibiting IRF4. In an experimental asthma model, mast cell-specific deficiency in IRF4 or administration of sialostatin L results in a strong reduction in asthma symptoms, demonstrating the immunosuppressive potency of tick-derived molecules.

The Effect of Walking Speed on Gait Variability in Healthy Young, Middle-aged and Elderly Individuals

Previous research with healthy young adults has suggested that the temporal structure of gait variability is not random but shows self-similarity that is dependent on speed. Specifically, the strength of the long-range correlation of stride intervals follows a quadratic relationship with the minimum values at the respective preferred walking speed (PWS). The purpose of this study was to investigate if this relationship is affected by increasing age. Ten healthy young, seven healthy, middle-aged and seven healthy, elderly adults completed five-minute walking trials at 80%, 90%, 100%, 110% and 120% of their PWS on a treadmill. We investigated the temporal structure of gait variability by using detrended fluctuation analysis. In addition, we computed the Coefficient of Variation (CV) to identify effects on amount of gait variability. Our results revealed a significant quadratic relationship between the temporal structure of gait variability and speed for all groups extending the previously reported existence of such a relationship in healthy young adults to older individuals. However, only significant negative linear relationships were found between amount of variability and speed providing support that this relationship is not quadratic but linear across individuals of different ages. In addition, we found that the examination of the temporal structure of gait variability is more sensitive in differentiating middle-age and younger individuals. If middle-age is where the aging process starts, then measures of the temporal structure of gait variability are essential as prognostic and diagnostic tools of aging.

CpG-loaded multifunctional cationic nanohydrogel particles as self-adjuvanting glycopeptide antitumor vaccines

Self-adjuvanting antitumor vaccines by multifunctional cationic nanohydrogels loaded with CpG. A conjugate consisting of tumor-associated MUC1-glycopeptide B-cell epitope and tetanus toxin T-cell epitope P2 is linked to cationic nanogels. Oligonucleotide CpG complexation enhances toll-like receptor (TLR) stimulated T-cell proliferation and rapid immune activation. This co-delivery promotes induction of specific MUC1-antibodies binding to human breast tumor cells without external adjuvant.

Antibody induction directed against the tumor-associated MUC4 glycoprotein

Mucin glycoproteins are important diagnostic and therapeutic targets for cancer treatment. Although several strategies have been developed to explore anti-tumor vaccines based on MUC1 glycopeptides, only few studies have focused on vaccines directed against the tumor-associated MUC4 glycoprotein. MUC4 is an important tumor marker overexpressed in lung cancer and uniquely expressed in pancreatic ductual adenocarcinoma. The aberrant glycosylation of MUC4 in tumor cells results in an exposure of its peptide backbone and the formation of tumor-associated glycopeptide antigens. Due to the low immunogenicity of these endogenous structures, their conjugation with immune stimulating peptide or protein carriers are required. In this study, MUC4 tandem-repeat glycopeptides were conjugated to the tetanus toxoid and used for vaccination of mice. Immunological evaluations showed that our MUC4-based vaccines induced very strong antigen-specific immune responses. In addition, antibody binding epitope analysis on glycopeptide microarrays, were demonstrating a clear glycosylation site dependence of the induced antibodies.

Enhanced immunogenicity of multivalent MUC1 glycopeptide antitumour vaccines based on hyperbranched polymers

A fully synthetic multivalent MUC1 glycopeptide vaccine based on a hyperbranched polyglycerol core induced IgG antibodies which strongly recognise epithelial tumour cells.

Endurance markers are related with local neuromuscular response for the intact but not for the ACL reconstructed leg during high intensity running

AIM

It has been demonstrated that the local neuromuscular response during high intensity exercise has a strong relationship with endurance markers. However, a diminished neuromuscular response has been reported for the operated leg in athletes having undergone anterior cruciate ligament reconstruction (ACLR). The purpose of the present study was to examine the relationships between endurance markers and the EMG response during high intensity running in ACLR athletes.

METHODS

Fourteen ACLR soccer players underwent a GXT test to volitional exhaustion and a 10-min bout of high intensity running. During the 10-min bout, EMG data were recorded at the 3rd and 10th minute from the vastus lateralis bilaterally using a telemetric system. The final EMG levels were expressed as a percentage of the initial values. Pearson moment product correlations were used to assess the relationship between the endurance markers of VO2max, velocity at lactate threshold (vLT), velocity at 4mM (V4) and the final EMG levels.

RESULTS

Final EMG levels for the intact leg had a very strong relationship with vLT (r=0.77, P=0.001) and a strong relationship with V4 (r=0.68, P=0.008). Final EMG levels for the reconstructed leg had moderate relationship with vLT (r=0.47, P=0.09) and V4 (r=0.52, P=0.06).

CONCLUSION

The neuromuscular response of the intact leg during high intensity running shows strong to very strong relationships with endurance markers. Failure of the ACLR leg to present relationships of similar strength may indicate that chronic perturbations modify the ability of the local muscular environment to tolerate sustained high intensity efforts.

Atypical hemolytic-uremic syndrome (HUS) with recovery after a long-lasting anuria: a case report

We report a case of a seven-year-old girl who suffered from atypical Hemolytic Uremic Syndrome (aHUS) complicated by septicaemia, central nervous system involvement, and cholangiitis. She remained anuric requiring treatment with peritoneal dialysis (PD) for a five-month period. In addition to conventional therapeutic measures including fresh frozen plasma (FFP) and blood cells transfusions she also underwent to plasma exchange (PE) treatment. Following a stormy hospitalization period of 17 weeks, the patient finally regained renal function and three years later she remains well on antihypertensive treatment and free of dialysis.

Anterior cruciate ligament reconstruction with a quadrupled hamstrings tendon autograft does not restore tibial rotation to normative levels during landing from a jump and subsequent pivoting

AIM

Recent research suggested that the anterior curciate ligament (ACL) reconstruction does not restore tibial rotation to normal levels when a bone patellar tendon bone (BPTB) graft is used during high demanding activities. Our goal was to determine if the usage of an alternative graft, as the quadrupled semitendinosus-gracilis (ST/G), restore tibial rotation to normal values in a population of athletically active individuals while performing a usual for their sport activity.

METHODS

Eleven subjects, all reconstructed with an ST/G graft, were assessed in vivo, 9 months postoperatively, while they jumped off a 40 cm platform, landed on the ground and subsequently pivoted at 90 degrees. The evaluation period was identified from initial foot contact with the ground, included the pivoting of the ipsilateral leg, and was completed upon touchdown of the contralateral leg. By that time the patients had already returned to their sports activities.

RESULTS

The maximum range of motion of the tibial rotation for the pivoting leg, during the evaluation period was found significantly (P=0.0001) larger in the reconstructed leg as compared to the intact contralateral, although both clinical and arthrometer assessments revealed restoration of anterior translation.

CONCLUSIONS

It was concluded that ACL reconstruction with an ST/G graft does not restore tibial rotation to normal levels during this high demanding activity. It seems that new surgical techniques are needed to better replicate the actual anatomy and function of the natural ACL in order to address this problem.

The effects of a plyometric training program on the latency time of the quadriceps femoris and gastrocnemius short-latency responses

AIM

The purpose of this study was to determine if a plyometric training program can affect the latency time of the quadriceps femoris and gastrocnemius short-latency responses (SLRs) of the stretch reflex.

METHODS

Sixteen healthy subjects (12 female and 4 male) were randomly assigned to either a control or a plyometric training group. Maximum vertical jump height (VJ) and SLRs of both quadriceps femoris and gastrocnemius were measured before and after a four week plyometric training program.

RESULTS

Plyometric training significantly increased VJ (mean+/-SEM) by 2.38+/-0.45 cm (P<0.05) and non-significantly decreased the latency time of the quadriceps femoris SLR (mean+/-SEM) 0.363+/-0.404 ms (P>0.05) and gastrocnemius SLR (mean+/-SEM) 0.392+/-0.257 ms (P>0.05). VJ results support the effectiveness of plyometric training for increasing VJ height.

CONCLUSIONS

The non-significant changes in the latency time of the quadriceps femoris and gastrocnemius SLRs seen in the training group suggest that performance improvements following a four-week plyometric training program are not mediated by changes in the latency time of the short-latency stretch reflex.

Consistency of performance of robot-assisted surgical tasks in virtual reality

The purpose of this study was to investigate consistency of performance of robot-assisted surgical tasks in a virtual reality environment. Eight subjects performed two surgical tasks, bimanual carrying and needle passing, with both the da Vinci surgical robot and a virtual reality equivalent environment. Nonlinear analysis was utilized to evaluate consistency of performance by calculating the regularity and the amount of divergence in the movement trajectories of the surgical instrument tips. Our results revealed that movement patterns for both training tasks were statistically similar between the two environments. Consistency of performance as measured by nonlinear analysis could be an appropriate methodology to evaluate the complexity of the training tasks between actual and virtual environments and assist in developing better surgical training programs.

A virtual reality training program for improvement of robotic surgical skills

The purpose of this study was to use a simulated virtual reality environment for training of surgical skills and then to identify if the learning that occurred was transferable to a real world surgical task. The virtual surgical tasks consisted of bimanual carrying, needle passing and mesh alignment. In this ongoing study, the experimental group (n = 5) was trained by performing four blocks of the virtual surgical tasks using the da Vinci surgical robot. Pre and post training, all subjects were tested by performing a suturing task on a "life-like" suture pad. The control group (n = 5) performed only the suturing task. Significantly larger pre and post differences were revealed in time to task completion (p < 0.05) and total distance travelled by the dominant side instrument tip (p < 0.01) in the experimental group as compared to the control group. These differences were specific to the suture running aspect of the surgical task. In conclusion, virtual reality surgical skills training may produce a significant learning effect that can transfer to actual robot-assisted laparoscopic procedures.

Validating advanced robot-assisted laparoscopic training task in virtual reality

The purpose of this study was to validate a complex robotic surgical task, mesh alignment, in virtual reality. Nine subjects unrolled and aligned a mesh onto an inanimate template for the mesh alignment task in both an actual (the da Vinci Robotic Surgical System) and a virtual environment. Data analysis included time to task completion, distance traveled, and speed, of the surgical instrument, as well as electromyography of the extensors and flexors of the dominant arm of the subject. Paired t-tests were used to compare the dependent variables between the actual and virtual environments. The virtual mesh alignment task was statistically similar for all variables except the flexor activity as compared to the actual task. In conclusion, virtual reality could be used as an effective environment to train the next generation of robot-assisted laparoscopic surgeons.