Engineered cytokine/antibody fusion proteins improve delivery of IL-2 to pro-inflammatory cells and promote antitumor activity

Progress in cytokine engineering is driving therapeutic translation by overcoming the inherent limitations of these proteins as drugs. The interleukin-2 (IL-2) cytokine harbors great promise as an immune stimulant for cancer treatment. However, the cytokine's concurrent activation of both pro-inflammatory immune effector cells and anti-inflammatory regulatory T cells, its toxicity at high doses, and its short serum half-life have limited clinical application. One promising approach to improve the selectivity, safety, and longevity of IL-2 is complexation with anti-IL-2 antibodies that bias the cytokine towards the activation of immune effector cells (i.e., effector T cells and natural killer cells). Although this strategy shows therapeutic potential in preclinical cancer models, clinical translation of a cytokine/antibody complex is complicated by challenges in formulating a multi-protein drug and concerns about complex stability. Here, we introduce a versatile approach to designing intramolecularly assembled single-agent fusion proteins (immunocytokines, ICs) comprising IL-2 and a biasing anti-IL-2 antibody that directs the cytokine's activities towards immune effector cells. We establish the optimal IC construction and further engineer the cytokine/antibody affinity to improve immune biasing function. We demonstrate that our IC preferentially activates and expands immune effector cells, leading to superior antitumor activity compared to natural IL-2 without inducing toxicities associated with IL-2 administration. Collectively, this work presents a roadmap for the design and translation of immunomodulatory cytokine/antibody fusion proteins.

Chlamydia trachomatis glyceraldehyde 3-phosphate dehydrogenase: Enzyme kinetics, high-resolution crystal structure, and plasminogen binding

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is an evolutionarily conserved essential enzyme in the glycolytic pathway. GAPDH is also involved in a wide spectrum of non-catalytic cellular 'moonlighting' functions. Bacterial surface-associated GAPDHs engage in many host interactions that aid in colonization, pathogenesis, and virulence. We have structurally and functionally characterized the recombinant GAPDH of the obligate intracellular bacteria Chlamydia trachomatis, the leading cause of sexually transmitted bacterial and ocular infections. Contrary to earlier speculations, recent data confirm the presence of glucose-catabolizing enzymes including GAPDH in both stages of the biphasic life cycle of the bacterium. The high-resolution crystal structure described here provides a close-up view of the enzyme's active site and surface topology and reveals two chemically modified cysteine residues. Moreover, we show for the first time that purified C. trachomatis GAPDH binds to human plasminogen and plasmin. Based on the versatility of GAPDH's functions, data presented here emphasize the need for investigating the Chlamydiae GAPDH's involvement in biological functions beyond energy metabolism.

A unified degree day model describes survivorship of Copitarsia corruda Pogue & Simmons (Lepidoptera: Noctuidae) at different constant temperatures

Predictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5 degrees C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (+/-13 SEM) days at 9.7 degrees C. Physiological age survival curves constructed with developmental base temperature (7.2 degrees C) did not correspond to those constructed with a senescence base temperature (5.9 degrees C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9-24.9 degrees C).

Copitarsia decolora (Lepidoptera: Noctuidae) larvae escaping from discarded asparagus: data in support of a pathway risk analysis

This research was undertaken to gather data in support of an assessment of the likelihood that Copitarsia decolora (Guenée) (Lepidoptera: Noctuidae), a pest of asparagus, Asparagus officinalis L., and other crops, could escape from the pathway followed by asparagus from the field to the consumer. Asparagus that is destroyed by cooking and consumption, being run through a trash compactor or garbage disposal, or being buried in a landfill probably cannot support development of C. decolora larvae. Much asparagus is discarded in dumpsters, however, and the time between disposal and removal to the landfill provides an opportunity for C. decolora to escape into the environment. Results of this study indicate that C. decolora cannot survive to the pupal stage on rotten asparagus, and survival on dried asparagus is low. However, larvae can survive at least 1 wk on both types of deteriorating asparagus held at 23.5 degrees C. In field trials, a small percentage of C. decolora larvae crawled out of a dumpster filled with asparagus after 1 wk.

The timing and sequence of multiple device-related complications in patients with indwelling subcutaneous ports

BACKGROUND

Multiple complications associated with venous access ports are a common occurrence. In an effort to define patterns of sequential complications in our community, we undertook a prospective analysis of adult cancer patients in whom a subcutaneous port was inserted.

METHODS

One hundred nineteen consecutive adult cancer patients in whom a subcutaneous port was inserted were observed prospectively for the development of complications.

RESULTS

Complications were identified in 70 of the 91 evaluable patients, while sequential complications were identified in 35 patients (38%). In aggregate, 121 complications were identified. The ball-valve effect, the most frequently identified problem, was found to occur disproportionately as a primary complication (52 of 70 versus 26 of 51, P <0.02). In contrast, port-related venous thrombosis was identified most frequently as a subsequent complication (11 of 51 versus 4 of 70, P <0.02). The only identified risk factor for the development of port-related complications was the ball-valve effect, found to be associated with the subsequent development of port-related venous thrombosis (9 of 52 versus 2 of 69, P <0.02).

CONCLUSIONS

Multiple sequential complications of subcutaneous ports are common and occur in a rather predictable order. The occurrence of port-related venous thrombosis in patients with an earlier, relatively minor vascular complication (ball-valve effect) suggests a cause-effect relationship. Insight into complication sequencing may lead to improved strategies for prevention and therapy.

The timing and sequence of multiple device-related complications in patients with long-term indwelling Groshong catheters

BACKGROUND

The function of long term indwelling venous access devices is commonly perturbed by postinsertion catheter-related complications (CRC). In an effort to assess the patterns of CRC in our community accurately, a prospective analysis of Groshong catheters in adult cancer patients was undertaken.

METHODS

Three hundred and twenty-four consecutive adult oncology patients in whom a Groshong catheter was utilized for long-term central venous access were observed for the development of a CRC. A subset analysis was undertaken of those catheters that developed one or more complications.

RESULTS

Among the 221 catheters with a primary complication, 176 additional complications were subsequently identified (109 2nd, 50 3rd, and 17 4th complicating events). Ball-valve effect (BVE), the most frequent complication, was found to occur disproportionately as a primary event (85 of 119 catheters, P < 0.01), whereas catheter-related venous thrombosis (CR-VT) was more likely to occur as a later, subsequent complication (46 of 66 catheters, P < 0.01). Although risk analysis affirmed a paucity of clinical predictors for developing a primary complication, patients with BVE as a first complication were at increased risk for developing a later episode of CR-VT.

CONCLUSIONS

Multiple sequential complications are common in patients with Groshong catheters, occurring in a rather predictable sequence. The increased risk of CR-VT in patients with catheters with an early complication suggests a cause-effect relationship. An awareness of this sequencing may lead to improved strategies for the prevention of primary and subsequent complications.

The Splitting Index: construction of a scale measuring the defense mechanism of splitting

The Splitting Index (SI), a self-report scale based on the writings of Kernberg (e.g., 1976) on self and object representations and the defense mechanism of splitting, was constructed. After development over the course of 6 pilot studies, the SI was validated through 2 further studies. Factor analyses revealed a 24-item scale with three 8-item subscales, measuring the splitting of self, family, and others' images. The SI and its subscales were demonstrated to be internally consistent and stable over a 4-week period. Convergent validity was supported by significant correlations with measures of borderline and narcissistic personality disorders, self-image stability, self-esteem, depression, and negative affectivity. Discriminant validity was demonstrated by near-zero correlations with two measures of cognitive complexity. Contrary to predictions, the SI was significantly correlated with the Dogmatism Scale (Rokeach, 1960), a third measure of cognitive complexity. Research and clinical applications of the SI are discussed.

The prognostic significance of the ball-valve effect in Groshong catheters

The aim of the work was to determine the prognostic significance of the ball-valve effect (BVE) in a population of adult cancer patients with long-term indwelling Groshong catheters. A prospective longitudinal study of 356 Groshong catheters utilized for long-term central venous access was carried out in adult oncology patients. A subset analysis was undertaken of those catheters that developed BVE. BVE was the most commonly identified impediment to normal catheter function, comprising 30% of all identified complications (119/397). BVE was also the most frequent de, novo (primary) complication (85 of 221, 38.5%), as well as the complication that occurred soonest in the life of the catheter (average = 61.2 days after insertion). Patients with BVE were likely to develop subsequent catheter-related venous thrombosis (20 of 30 compared to 65 of 191, P 0.01), but no other significant catheter-related complication. Patients more than 65 years old had an increased incidence of BVE as the primary complication (46 of 85 compared to 49 of 136, P = 0.01). while patients with breast cancer had a lower incidence (12 of 85 compared to 36 of 136, P = 0.04). No catheter was removed as a result of the development of BVE. The onset of BVE represents an elemental perturbation of catheter function which portends the development of other, more significant vascular occlusive complications. Phenomenologically, BVE has been overshadowed in significance by the clinically more dramatic venous thrombosis and catheter-related infections. The true significance of BVE can not be determined until the impact of preventing this early complication on the incidence of secondary complications is analyzed prospectively.

Groshong catheter-associated subclavian venous thrombosis

PURPOSE

To identify factors associated with the development of clinically significant venous thrombosis in cancer patients with long-term indwelling subclavian Groshong catheters (GC). Also, to assess both the subsequent performance of affected catheters and the effect of heparin and warfarin therapy on subsequent catheter function and longevity.

METHODS

Longitudinal study of the outcome of clinical practice. Subset analysis of those catheters developing catheter-related venous thrombosis (CRVT).

RESULTS

Thirty-seven cases of CRVT were identified in a population of 255 consecutive patients in whom a GC was inserted. Seventy percent of the thrombi occurred after an episode of previous catheter dysfunction; only 30% of the thrombi occurred de novo. An unexpectedly high risk of thrombosis was associated with insertion into the left-subclavian circulation (25 of 35 versus 135 of 220, p = 0.02) or with an antecedent episode of aspiration difficulty ("ball-valve effect" [BVE]) (20 of 35 versus 60 of 220, p < 0.01). No correlation was identified between thrombosis and tumor type, tumor histology, or preexisting medical disorders. Once identified, 79% of the involved patients received anticoagulant therapy with sequential heparin and warfarin. Overall longevity of the catheters preserved by anticoagulation (mean dwell = 202 days) far exceeded catheter longevity among the population of catheters that never developed thrombosis (mean dwell = 142 days). The mean catheter longevity after thrombosis (169 days) also exceeded the mean dwell time of all other catheters that were complication-free.

CONCLUSIONS

CRVT is more likely in patients in whom the catheter is inserted in the left-subclavian circulation or who have experienced a previous episode of aspiration difficulty with the catheter (BVE). Catheter preservation with sequential heparin and warfarin therapy precludes the need for catheter removal and extends dramatically the useful life of the catheter.

Human physiological response and adaption to ammonia

Other than anecdoted observations, there are no published reports on the physiological effects of ammonia at concentrations normally encountered industrially or information on whether inurement develops after repeated exposure. Six unacclimated male and female volunteers were exposed six hours per day over a six week period to concentrations of 25, 50, and 100 ppm ammonia in an industrial environment, under strict medical surveillance. Inurement to eye, nose, and throat irritation was demonstrated after two to three weeks in addition to short-term subjective adaption. There were no significant differences between subjects or controls on common biological indicators, in physical examinations, or in performance of normal job duties. After acclimation, continuous exposure to 100 ppm, with occasional excursions to 200 ppm, is easily tolerated and has no observed effect on general health.