Generation of PSA-reactive effector cells after vaccination with a PSA-based vaccine in patients with prostate cancer.

BACKGROUND: JBT 1001 is a vaccine used for therapy of prostate cancer (CA), which consists of recombinant prostate-specific antigen (PSA) with lipid A formulated in liposomes. Patients with prostate CA were vaccinated with JBT 1001 emulsified in mineral oil (n = 5) or with the vaccine in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) administered locally at the site of vaccination (n = 5). Frequency of PSA-reactive T cells was measured in peripheral blood mononuclear cells (PBMC) before and after immunization, using an interferon-gamma (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay with autologous dendritic cells (DC) as antigen-presenting cells. The hypothesis tested was that PSA-based vaccines induce T cell responses to human PSA. METHODS: In order to expand precursor cells, in vitro sensitization (IVS) was performed. Microcultures of peripheral blood lymphocytes (PBL) (1 x 10(5)/well) in medium supplemented with interleukin-2 (IL-2) (10 IU/ml) and interleukin-7 (IL-7) (10 ng/ml) were stimulated twice (day 0 and day 7) with monocyte-derived autologous DC, generated by culture with interleukin-4 (IL-4) and GM-CSF and pulsed with PSA (10 microg/ml) at an effector to stimulator ratio of 10:1. ELISPOT assays were performed on day 14 of culture. In addition, PBMC were separated on immunobeads into CD4(+) and CD8(+) subsets for ELISPOT assays performed without IVS. RESULTS: Two patients had PSA-reactive responses before vaccination (frequency range, 1/700-1/4,400). After vaccination, 8/10 patients had measurable PSA-reactive T-cell frequencies, ranging from 1/200-1/1900, using IVS. In contrast, without IVS, but after immunoselection to enrich in CD8(+) and CD4(+) T cells, only 2/10 patients had detectable PSA-reactive T cells after vaccination, at a frequency ranging from 1/2,600-1/4,000. CONCLUSIONS: Vaccination with PSA formulated into liposomes induced T-cell responses in 8/10 patients with prostate carcinoma. The frequency of PSA-reactive precursor T cells was relatively low in the blood of these patients, and IVS, leading to amplification of the precursor cells prior to ELISPOT, was necessary for quantification of the PSA-responding T cells. Cellular responses to PSA were predominantly mediated by CD4(+) T lymphocytes.

Cellular immunity in depressed, conduct disorder, and normal adolescents: role of adverse life events.

OBJECTIVE: To determine whether adolescents with major depressive disorder have disturbances in their cellular immunity and to study whether the immunological changes detected are specific to depression or are general responses to stress. METHOD: Twenty subjects with major depressive disorder, 17 nondepressed subjects with conduct disorder, and 17 normal adolescents were recruited. Subjects were assessed with a clinical interview for DSM-III-R and a modified version of the Coddington Life Events Checklist. Blood samples were drawn for total white blood cells, lymphocytes subsets, natural killer cell activity, lymphocyte proliferation response to phytohemagglutinin, and cortisol plasma levels. RESULTS: Overall, there were no significant between-group differences in any of the cellular immune measurements. Natural killer cell activity was significantly negatively correlated with past year and lifetime adverse life events across all effector-target cell ratios. Controlling for diagnoses and socioeconomic status yielded similar results. There were no significant effects of age, sex, race, sleep, nutrition, cigarette use, menstrual cycle, or cortisol on any of the immunological variables. CONCLUSIONS: In this sample of adolescents, we found that independent of the diagnoses and socioeconomic status, increases in adverse life events were associated with low natural killer cell activity.

Use of antibody to membrane adenosine triphosphatase in the study of bacterial relatioships.

An antiserum to Ca(2+)-activated adenosine triphosphatase from membranes of Micrococcus lysodeikticus cross-reacted in agar gels with membrane adenosine triphosphatases from other pigmented micrococci and related species. Species of Micrococcus and Sarcina showed different levels of inhibition of adenosine triphosphatase activities in heterologous reactions with antiserum. Inter- and intraspecific relationships based on the inhibition reaction were compared with an independent parameter, namely the quantitative and qualitative composition of the bacterial membrane phospholipids and fatty acids. The guanine plus cytosine contents in the deoxyribonucleic acid of the species studied correlated well with the serological cross-reactivity of adenosine triphosphatases from their membranes. The types of cross-bridges found in the peptidoglycans of these cocci were also compared with the other properties. The results suggest that an antiserum specific for a major membrane protein may be a reliable and most useful adjunct in studying bacterial serotaxonomy.