DNA vaccination of mice with plasmid expressing human papillomavirus 6 major capsid protein L1 elicits type-specific antibodies neutralizing pseudovirions constructed in vitro

Human papillomavirus 6 (HPV 6) causes benign condylomata. As a model for HPV vaccine development, we tested a HPV 6 DNA vaccine candidate, constructed by subcloning the major capsid protein (L1) gene into an expression plasmid having the cytomegalovirus promoter, for its immunogenicity in BALB/c mice. Three intracutaneous inoculations of the plasmid with a gene gun at 2-week intervals elicited anti-L1 serum antibodies. The antibodies were found to recognize highly type-specific, conformation-dependent epitopes, including those to neutralize pseudovirions capable of inducing beta-galactosidase in infected monkey COS-1 cells. The data support the idea that immunization with DNA capable of expressing HPV L1 can be used as an HPV vaccine strategy for humans.     

Vitamin D receptor gene polymorphism is associated with serum total and ionized calcium concentration

Restriction fragment length polymorphisms of the vitamin D receptor gene have recently been reported to be associated with changes in bone mineral density. Alterations in systemic calcium balance and Ca-regulating hormones such as 1,25(OH)2 vitamin D3 and parathyroid hormone have been demonstrated in essential hypertension. We investigated the relationship between polymorphisms of the vitamin D receptor gene and systemic Ca metabolism in patients with essential hypertension and in normotensives. We compared 147 subjects with essential hypertension and 100 normotensive control subjects. The genotype distribution and derived allele frequencies for the vitamin D receptor gene were similar in the two groups (genotype bb/Bb/BB and allele B/b: 60.1/32.6/7.2 and 0.24/0.76 in hypertensives vs. 56.0/36.0/8.0 and 0.26/0.74 in normotensive subjects). Serum concentrations of total Ca in the bb, Bb, and BB groups were, respectively, 4.5+/-0.3 vs. 4.5+/-0.4 vs. 4.4+/-0.5 mmol/l in normotensives and 4.6+/-0.3 vs. 4.6+/-0.4 vs. 4.4+/-0.5 mmol/l in hypertensives. Ionized Ca levels were 1.17+/-0.04 vs. 1.16+/-0.04 vs. 1.15+/-0.04 mmol/l in normotensives and 1.16+/-0.04 vs. 1.16+/-0.04 vs. 1.14+/-0.05 mmol/l in hypertensives, respectively. These results indicate that the BB genotype of the vitamin D receptor gene is associated with lower serum Ca levels but is not a useful predictive marker for the development of essential hypertension in Japanese subjects.     

Inborn errors of metabolism discovered in Asian department of pediatrics and mental retardation research center

To heighten the effectiveness of chemical diagnosis for inborn errors of metabolism (IEM) using urease pretreatment and GC-MS analysis, a sample collection and transportation method was contrived. The resulting "filter paper set" allows simple urine collection and transportation, and enables anyone from anywhere to receive the GC-MS analysis without the limitations of place or time. Using filter paper sets, high-risk screening of undiagnosed children or mentally retarded children with unknown cause was conducted in cooperation with hospitals and universities in several Asian countries. During 8 months 203 patients from China and India were analyzed and 20 cases of IEM were chemically diagnosed. These diagnoses greatly contributed to the treatment of children with intractable diseases who lived in Asian countries where analytical techniques and facilities for IEM were not sufficient.     

Adhesion mediated by LFA-1 is required for efficient IL-12-induced NK and NKT cell cytotoxicity

Interleukin 12 (IL-12)-activated NK1.1+TCRalpha beta+ (NKT2) and NK1.1+TCRalpha beta- (NK) cells exhibit cytotoxic activity against a wide variety of tumor cells in the absence of prior sensitization. Here we demonstrate that the integrin adhesion receptor LFA-1 (CD11a/CD18) regulates the cytotoxic activity of IL-12-activated NKT and NK cells against YAC-1 and EL-4 tumor cells. Differentiation in vivo and the expression of the cytolytic effector molecules perforin and Fas-L were comparable in both IL-12-activated NKT and NK cells from LFA-1-/ - and LFA-1+/+ mice. However, LFA-1-/-IL-12-activated NKT and NK cells showed impaired conjugate formation with target cells. These results provide the first genetic evidence for a role for an adhesion receptor in killing by IL-12-activated NK cells.     

Current source density analysis of ON/OFF channels in the frog optic tectum

In the vertebrate retina, it is well known that an ON/OFF dichotomy is present. In other words, ON-center and OFF-center cells participate in segregated pathways morphologically and physiologically. However, there is no doubt that integration of both channels is necessary to generate the complicated response properties of visual neurons in higher optic centers. So far, functional organization of the ON and OFF channels in the optic centers has not been demonstrated at the level of neuronal populations. In this review article, we summarize our experimental approaches to demonstrate functional organization of the ON and OFF channels using current source density (CSD) analysis in the frog optic tectum. First, we show that one-dimensional CSD analysis, assuming constant conductivity, is applicable in the tectal laminated structure. The CSD depth profile of a response to electrical stimulation of the optic tract is composed of three current sinks (A, B, and D) in the retinorecipient layers and two current sinks (C and E) below those layers. This result is in agreement with previous morphological and physiological findings, and shows that CSD analysis is very useful to demonstrate the flow of visual information processing. Second, CSD analysis of tectal responses evoked by diffuse light ON and OFF stimuli reveals obviously different distributions of synaptic activity in the laminar structure. Two or three current sinks (I, II and III) are generated in response to ON stimulation only in the retinorecipient layers, while up to six current sinks (IV, V, VI, VII, VIII and IX) to OFF stimulation throughout the tectal layers. Based on well known properties of retinal ganglion cells of the frog, possible neuronal mechanisms underlying each current sinks and their functional roles in visually guided behavior are considered.