Evidence for a Common Toolbox Based on Necrotrophy in a Fungal Lineage Spanning Necrotrophs, Biotrophs, Endophytes, Host Generalists and Specialists

The Sclerotiniaceae (Ascomycotina, Leotiomycetes) is a relatively recently evolved lineage of necrotrophic host generalists, and necrotrophic or biotrophic host specialists, some latent or symptomless. We hypothesized that they inherited a basic toolbox of genes for plant symbiosis from their common ancestor. Maintenance and evolutionary diversification of symbiosis could require selection on toolbox genes or on timing and magnitude of gene expression. The genes studied were chosen because their products have been previously investigated as pathogenicity factors in the Sclerotiniaceae. They encode proteins associated with cell wall degradation: acid protease 1 (acp1), aspartyl protease (asps), and polygalacturonases (pg1, pg3, pg5, pg6), and the oxalic acid (OA) pathway: a zinc finger transcription factor (pac1), and oxaloacetate acetylhydrolase (oah), catalyst in OA production, essential for full symptom production in Sclerotinia sclerotiorum. Site-specific likelihood analyses provided evidence for purifying selection in all 8 pathogenicity-related genes. Consistent with an evolutionary arms race model, positive selection was detected in 5 of 8 genes. Only generalists produced large, proliferating disease lesions on excised Arabidopsis thaliana leaves and oxalic acid by 72 hours in vitro. In planta expression of oah was 10–300 times greater among the necrotrophic host generalists than necrotrophic and biotrophic host specialists; pac1 was not differentially expressed. Ability to amplify 6/8 pathogenicity related genes and produce oxalic acid in all genera are consistent with the common toolbox hypothesis for this gene sample. That our data did not distinguish biotrophs from necrotrophs is consistent with 1) a common toolbox based on necrotrophy and 2) the most conservative interpretation of the 3-locus housekeeping gene phylogeny – a baseline of necrotrophy from which forms of biotrophy emerged at least twice. Early oah overexpression likely expands the host range of necrotrophic generalists in the Sclerotiniaceae, while specialists and biotrophs deploy oah, or other as-yet-unknown toolbox genes, differently

SERUM LEVELS OF SOLUBLE CD8 ARE INCREASED IN PATIENTS WITH B CHRONIC LYMPHOCYTIC LEUKEMIA.

Serum levels of the soluble form of the CD8 (s-CD8) antigen were evaluated in the peripheral blood of 44 patients with B-CLL, using an enzyme-linked immunosorbent assay, and were correlated with clinical features and relevant hematological and immunological data. Increased values were observed with respect to normal age-matched controls (mean +/- S.E.M. 603 U/ml +/- 81 vs. 315 U/ml +/- 31, respectively; P less than 0.0001). This increase was observed in all stages of the disease, excluding stage 0 (mean 277 U/ml +/- 45). A general trend pointing to lower values overall in patients with less invasive disease was observed. In fact, the rank correlation test showed that the serum levels of s-CD8 correlate significantly with the WBC counts, the CD4/CD8 ratio, and also with the levels of serum immunoglobulins. On the contrary, no correlation was observed between s-CD8 levels and the absolute number of circulating CD8+ cells in individual cases. Therefore, the increase of s-CD8 is unlikely to be a mere expression of the increase of the CD8 cell number, but seems related to an increase of the activation phenomena involving the CD8+ T cell subset

Serum levels of soluble CD8 molecule are increased in patients with B chronic lymphocytic leukemia

Serum levels of the soluble form of the CD8 (s-CD8) antigen were evaluated in the peripheral blood of 44 patients with B-CLL, using an enzyme-linked immunosorbent assay, and were correlated with clinical features and relevant hematological and immunological data. Increased values were observed with respect to normal age-matched controls (mean +/- S.E.M. 603 U/ml +/- 81 vs. 315 U/ml +/- 31, respectively; P less than 0.0001). This increase was observed in all stages of the disease, excluding stage 0 (mean 277 U/ml +/- 45). A general trend pointing to lower values overall in patients with less invasive disease was observed. In fact, the rank correlation test showed that the serum levels of s-CD8 correlate significantly with the WBC counts, the CD4/CD8 ratio, and also with the levels of serum immunoglobulins. On the contrary, no correlation was observed between s-CD8 levels and the absolute number of circulating CD8+ cells in individual cases. Therefore, the increase of s-CD8 is unlikely to be a mere expression of the increase of the CD8 cell number, but seems related to an increase of the activation phenomena involving the CD8+ T cell subset

Increased serum levels of soluble interleukin-2 receptor in patients with systemic lupus erythematosus and rheumatoid arthritis

In this study we investigated the serum levels of a released soluble form of the interleukin-2 receptor (sIL-2R) in 42 patients with rheumatoid arthritis and in 12 cases of systemic lupus erythematosus. Data were evaluated in relationship to the clinical phase and compared with those observed in normal controls (N = 56) and in osteoarthritis (N = 7). Increased levels were observed in both rheumatoid arthritis (mean +/- SE, 604 +/- 49 U/ml) and systemic lupus erythematosus (1438 +/- 481 U/ml). These values were significantly higher than in control (256 +/- 15 U/ml; P less than 0.001) and in osteoarthritis (298 +/- 33 U/ml; P less than 0.001) groups. In addition, the highest values were associated with the active phases of both rheumatoid arthritis (active vs inactive, 771 +/- 78 vs 451 +/- 39 U/ml; P less than 0.001) and systemic lupus erythematosus (active vs inactive, 2108 +/- 489 vs 499 +/- 75 U/ml; P less than 0.001). Our findings suggest that the detection of sIL-2R in rheumatoid arthritis and in systemic lupus erythematosus may represent a good marker of disease activity, which indirectly indicates the ongoing activation and/or proliferation of immunoreactive cells which are involved in the pathogenetic events of these autoimmune conditions

Increased levels of soluble interleukin-2 receptor in the serum of patients with human immunodeficiency virus infection

The serum levels of a soluble form of the interleukin-2 receptor (sIL-2R) were investigated in 92 patients with human immunodeficiency virus (HIV) infection, ranging from asymptomatic cases to full-blown AIDS. Increased values were found in 69.5% of cases. The overall mean was significantly higher (p less than 0.001) in HIV-infected patients (mean +/- SD = 709.3 +/- 369.4 U/ml) than in the seronegative risk group controls (383.9 +/- 140.5) and normal controls (256.4 +/- 114.5). No major differences were found among the patient groups (asymptomatic infection, persistent generalized lymphadenopathy, symptomatic infection, and full-blown AIDS). These data suggest that the measurement of serum sIL-2R levels may represent a useful biological tool for evaluating T-cell activation phenomena occurring in HIV infection. Since the soluble interleukin-2 receptor maintains the capacity of binding interleukin-2, the increased levels found in HIV infection may play a contributory role towards the in vitro and in vivo impairment of a number of interleukin-2-dependent functions described in this disease. On clinical grounds, the excess of sIL-2R could help to explain the lack of therapeutic effect and little immunological variations following the in vivo administration of interleukin-2