The occupational aspirations and expectations of two populations of boys in grades 2, 4, 6, and 8 were examined in order (1) to describe what is unique about the development of job preferences among urban ghetto children who live in settings where many adult males are not well attached to the labor force and (2) to examine 6 reasons for any age- and population-dependent patterns there might be in job aspirations and job expectations. Findings show that boys tend to be more realistic about occupational aspirations and expectations the older they are; that from second grade on the occupational expectations of inner-city boys mirror existing race and class differences in adult job holdings; that the gap between occupational aspirations and expectations is greater for the ghetto boys and remains roughly constant in size across the grades examined; and that the lower occupational expectations of the inner-city boys are strongly related to their lower educational expectations, with these educational expectations being associated with fewer poor boys having a biological father at home and with more of these boys seeing obstacles to success in the local social setting. But, the lower occupational expectations of the ghetto boys are not due to having fewer positive role models or believing that schooling will not pay off for them in the future as it does for others.

ILK (beta1-integrin-linked protein kinase) is a recently identified 59-kDa serine/threonine protein kinase that interacts with the cytoplasmic domain of the beta1-integrin containing four ankyrin-like repeats. We have developed a polyclonal antibody against ILK and explored the ILK immunoreactivity in normal human cells and tissues. ILK was mainly expressed in cardiac muscle and skeletal muscles. Surprisingly, ILK expression was observed in Ewing's sarcoma (ES; 100%), primitive neuroectodermal tumour (PNET; 100%), medulloblastoma (100%), and neuroblastoma (33.3%), whereas other small round cell sarcomas were not stained by the anti-ILK antibody. These results suggest that ILK could be a novel marker for tumours with primitive neural differentiation. Our findings support the notion that ES is a tumour that is closely related to PNET and that both originate from the neuroectoderm. ILK may be a sensitive and specific immunohistochemical marker and useful for the positive identification of ES and PNET in formalin-fixed, paraffin-embedded tissue sections.

Members of protein kinase D (PKD) family serine/threonine kinases (PKD1, PKD2 and PKD3) are expressed in wide range of cells and regulate various cellular responses including immune responses. We have previously shown that PKD is involved in the signaling pathways of a human CD4(+) T cell clone stimulated with its cognate antigen. Contrary to foregoing publications, PKD1 mRNA was not detected in human T cells, Jurkat cells and mouse thymocytes and splenocytes. Instead, mass-spectrometric and reverse transcription-PCR analyses revealed that PKD2 was predominant in T cells. To investigate the roles of PKD2, wild-type (WT) and constitutively active (CA) PKD2 were expressed in Jurkat cells together with IL-2 promoter-driven reporter gene. Expression of WT-PKD2 enhanced IL-2 promoter activity upon stimulation with anti-CD3 mAb, while expression of CA-PKD2 inhibited IL-2 promoter activity and induced cell death. Although the cell death was suppressed by the treatment with caspase inhibitor, the IL-2 promoter activity was rarely recovered in CA-PKD2-expressing cells upon TCR stimulation. WT-PKD2 localized mainly in the cytoplasm translocated into the nucleus after TCR stimulation, while CA-PKD2 was present in both the cytoplasm and the nuclei before and after stimulation. Proteomic analyses revealed that CA-PKD2 enhanced the amount of phosphorylated SET protein, a histone chaperon that regulates histone acetylation, in Jurkat cells and the recombinant SET protein was phosphorylated by CA-PKD2 in vitro. The data provide a renewing insight into the subset of PKD family kinases expressed in T cells and suggest that PKD2 is involved in IL-2 promoter regulation and cell death depending on its activity upon TCR stimulation.

SummaryThis study examined whether cell cycle regulatory proteins, such as cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors, regulate type II collagen expression and mediate interlukin-1 (IL1b)-induced suppression of type II collagen expression in articular chondrocytes. IL-1b inhibited type II collagen expression, but activated CDK6. Ectopic expression of CDK2 did not alter type II collagen expression. However, overexpression of CDK6 inhibited type II collagen expression, whereas inhibition of CDK6 activity blocked IL-1b-induced suppression of type II collagen expression. IL-1b upregulated the expression of cyclin D1, which is known to activate CDK6. In turn, overexpression of cyclin D1 suppressed type II collagen expression. In contrast to cyclin D1, IL-1b triggered down-regulation of the CDK inhibitor, p21. Overexpression of p21 blocked IL-1b-or CDK6-induced suppression of type II collagen expression. Our results collectively indicate that CDK6/ cyclin D1/p21 complex regulates type II collagen expression in articular chondrocytes. IUBMB Life, 59: 90-98, 2007

The interactions between peptide/MHC complexes and their cognate TCR are essential for various T cell responses. However, the relationship between the avidity of TCR ligand and the subsequent intracellular signaling through the TCR is still unclear. To investigate the effects of TCR ligand avidity on TCR-mediated signaling, we established L cells expressing HLA-DR4 molecules covalently linked with agonistic peptide (highaffinity ligand) or altered peptide ligand (APL; low-affinity ligand) at various densities as APC for a cognate human CD4 + T cell clone. Using this system, we demonstrated that the T cell clone stimulated with APL/HLA-DR4 complexes presented at an excessive density provoked the up-regulation of CD69, IL-2 production and proliferation, but no detectable phosphorylation of ZAP-70/LAT/SLP-76. Furthermore, in contrast to the high-affinity stimulation, the low-affinity stimulation evoked delayed and sustained activation of the B-Raf/extracellular signal-regulated kinase (ERK) pathway without Raf-1 activation. The strength and duration of B-Raf/ERK activations closely correlated with the density of the TCR ligand. A knockdown approach confirmed that B-Raf activation was indispensable for the APL-induced T cell responses. These observations suggest that the differences in TCR-peptide/MHC interactions reflect the strength and duration of B-Raf/Raf-1/ERK activation in the human CD4 + T cells.