Clinical response after intradermal immature dendritic cell vaccination in metastatic melanoma is associated with immune response to particulate antigen

Metastatic melanoma is poorly responsive to treatment, and immunotherapeutic approaches are potentially beneficial. Predictors of clinical response are needed to identify suitable patients. We sought factors associated with melanoma-specific clinical response following intradermal vaccination with autologous melanoma peptide and particulate hepatitis B antigen (HBsAg)-exposed immature monocyte-derived dendritic cells (MDDC). Nineteen patients with metastatic melanoma received a maximum of 8, 2-weekly vaccinations of DC, exposed to HBsAg in addition to autologous melanoma peptides. A further 3 patients received an otherwise identical vaccine that did not include HBsAg. Patients were assessed 1-2 monthly for safety, disease volume, and cellular responses to HBsAg and melanoma peptide. There was no significant toxicity. Of 19 patients receiving HBsAg-exposed DC, 9 primed or boosted a cellular response to HBsAg, and 10 showed no HBsAg response. HBsAg-specific responses were associated with in vitro T cell responses to melanoma peptides and to phytohemagglutinin (PHA). Zero out of 10 non-HBsAg-responding and 4/9 HBsAg-responding patients achieved objective melanoma-specific clinical responses or disease stabilization- 1 complete and 2 partial responses and I case of stable disease (P=0.018). Development of melanoma-specific cellular immunity and T cell responsiveness to mitogen were greater in the group of patients responding to HBsAg. Therefore stimulation of an immune response to nominal particulate antigen was necessary when presented by melanoma peptide-exposed immature DC, to achieve clinical responses in metastatic melanoma. Since general immune competence may be a determinant of treatment response, it should be assessed in future trials on DC immunotherapy.

Infection of the immature stages of Diadegma semiclausum, an endolarval parasitoid of the diamondback moth, by Beauveria bassiana

Interactions between the immature stages of Diadegma semiclausum, an endolarval parasitoid of Plutella xylostella, and the fungal entomopathogen Beauveria bassiana were investigated in the laboratory. Detrimental effects of B. bassiana on D. semiclausum cocoon production and adult parasitoid emergence increased with increasing pathogen concentration and some parasitoid larvae became infected by B. bassiana within hosts. The negative impact of B. bassiana on D. semiclausum cocoon production decreased as temporal separation between parasitism and pathogen exposure increased. Adult parasitoid emergence was significantly compromised by the highest rates of B. bassiana tested even when exposure of host larvae to the pathogen was delayed until one day before predicted parasitoid cocoon formation. Parasitoid pupae were infected by the pathogen in all B. bassiana treatments which did not preclude their development. (C) 2004 Elsevier Inc. All rights reserved.

Home-range sizes and bower visitation patterns of immature male Satin Bowerbirds (Ptilonorhynchus violaceus)

Adult male Satin Bowerbirds build and decorate stick bowers to which they attract females for matings; females choose among males based on these complex bowers, decorations placed at these bowers, and displays consisting of vocalisations and posturing. Male Satin Bowerbirds undergo an extended period of delayed morphological maturation during which they retain female-like plumage and are assumed to learn adult male behavioural traits. Little is known, however, of how immature males acquire the ability to display and build and decorate bowers, except that they observe the displays of adult males at adults' bowers, and practise their own displays at both adults' and 'practice' bowers. We present data on the home ranges and movement patterns of six immature males, acquired through radio-tracking at the Bunya Mountains in south-east Queensland. Home-range size averaged 13.67 +/- 3.38 ha and immature males visited only some of the bowers located in their home ranges. On average, they visited 2.33 +/- 0.52 adults' bowers and 4.00 +/- 2.00 practice bowers.

Interplay between plasma hormone profiles, sex and body condition in immature hawksbill turtles (Eretmochelys imbricata) subjected to a capture stress protocol

We investigated plasma hormone profiles of corticosterone and testosterone in immature hawksbill turtles (Eretmochelys imbricata) in response to a capture stress protocol. Further, we examined whether sex and body condition were covariates associated with variation in the adrenocortical response of immature turtles. Hawksbill turtles responded to the capture stress protocol by significantly increasing plasma levels of corticosterone over a 5 h period. There was no significant sex difference in the corticosterone stress response of immature turtles. Plasma testosterone profiles, while significantly different between the sexes, did not exhibit a significant change during the 5 h capture stress protocol. An index of body condition was not significantly associated with a turtle's capacity to produce plasma corticosterone both prior to and during exposure to the capture stress protocol. In summary, while immature hawksbill turtles exhibited an adrenocortical response to a capture stress protocol, neither their sex nor body condition was responsible for variation in endocrine responses. This lack of interaction between the adrenocortical response and these internal factors suggests that the inactive reproductive- and the current energetic- status of these immature turtles are important factors, that could influence plasma hormone profiles during stress. (C) 2003 Elsevier Inc. All rights reserved.

Evaluating trends in abundance of immature green turtles, Chelonia mydas, in the Greater Caribbean

Many long-lived marine species exhibit life history traits. that make them more vulnerable to overexploitation. Accurate population trend analysis is essential for development and assessment of management plans for these species. However, because many of these species disperse over large geographic areas, have life stages inaccessible to human surveyors, and/or undergo complex developmental migrations, data on trends in abundance are often available for only one stage of the population, usually breeding adults. The green turtle (Chelonia mydas) is one of these long-lived species for which population trends are based almost exclusively on either numbers of females that emerge to nest or numbers of nests deposited each year on geographically restricted beaches. In this study, we generated estimates of annual abundance for juvenile green turtles at two foraging grounds in the Bahamas based on long-term capture-mark-recapture (CMR) studies at Union Creek (24 years) and Conception Creek (13 years), using a two-stage approach. First, we estimated recapture probabilities from CMR data using the Cormack-Jolly-Seber models in the software program MARK; second, we estimated annual abundance of green turtles. at both study sites using the recapture probabilities in a Horvitz-Thompson type estimation procedure. Green turtle abundance did not change significantly in Conception Creek, but, in Union Creek, green turtle abundance had successive phases of significant increase, significant decrease, and stability. These changes in abundance resulted from changes in immigration, not survival or emigration. The trends in abundance on the foraging grounds did not conform to the significantly increasing trend for the major nesting population at Tortuguero, Costa Rica. This disparity highlights the challenges of assessing population-wide trends of green turtles and other long-lived species. The best approach for monitoring population trends may be a combination of (1) extensive surveys to provide data for large-scale trends in relative population abundance, and (2) intensive surveys, using CMR techniques, to estimate absolute abundance and evaluate the demographic processes' driving the trends.

A population of HLA-DR+ immature cells accumulates in the blood dendritic cell compartment of patients with different types of cancer

Dendritic cell (DC) defects are an important component of immunosuppression in cancer. Here, we assessed whether cancer could affect circulating DC populations and its correlation with tumor progression. The blood DC compartment was evaluated in 136 patients with breast cancer, prostate cancer, and malignant glioma. Phenotypic, quantitative, and functional analyses were performed at various stages of disease. Patients had significantly fewer circulating myeloid (CD11c(+)) and plasmacytoid (CD123(+)) DC, and a concurrent accumulation of CD11c(-)CD123(-) immature cells that expressed high levels of HLA-DR+ immature cells (DR+IC). Although DR+IC exhibited a limited expression of markers ascribed to mature hematopoietic lineages, expression of HLA-DR, CD40, and CD86 suggested a role as antigen-presenting cells. Nevertheless, DR+IC had reduced capacity to capture antigens and elicited poor proliferation and interferon-gamma secretion by T-lymphocytes. Importantly, increased numbers of DR+IC correlated with disease status. Patients with metastatic breast cancer showed a larger number of DR+IC in the circulation than patients with local/nodal disease. Similarly, in patients with fully resected glioma, the proportion of DR+IC in the blood increased when evaluation indicated tumor recurrence. Reduction of blood DC correlating with accumulation of a population of immature cells with poor immunologic function may be associated with increased immunodeficiency observed in cancer.