Down-regulation of murine collagen-induced arthritis by a T cell hybridoma

T cell hybridoma cell lines were generated by somatic cell fusion of BW 5147 myeloma cells and splenic cells from mice suppressed for collagen-induced arthritis (CIA). Two cell lines were characterized for their cell surface phenotype, antigen recognition and capacity to down-regulate the erythema and edema associated with CIA. Cell line T101N was determined to portray the cell surface phenotype Ly1+2- L3T4- Thy1+ by a direct binding assay. Cell line T104B1 was determined to express only the Thy1+ alloantigen. Panning studies, measurement of IL-2 production in vitro and the suppression of antibodies to type I and type II collagen in vivo indicate that the hybridoma cells are not isotype specific in their recognition of the polymorphic interstitial collagens. Down-regulation of the erythema and edema of CIA occurred on injection of 1 X 10(5) T101N cells but not T104B1 cells. Histology of the tarsus region of the hind paw of CIA mice 33 days after the administration of T101N cells showed contrasting histopathology compared to that of CIA mice. The joints of CIA mice given T101N cells showed aligned articular surfaces resembling normal joint structure and only residual pannus. The data indicate that collagen-specific cloned T cell lines can modulate the gross pathology and joint architecture of joints exhibiting CIA.     

UDP-Gal: <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine β 1–4 galactosyltransferase expressing live attenuated parasites as vaccine for visceral leishmaniasis

As compared to cutaneous leishmaniasis, vaccination against visceral leishmaniasis (VL) has received limited attention. In this study, we demonstrate for the first time that an UDP-Galactose: N-acetylglucosamine β 1–4 galactosyltransferase (GenBank Accession No. EF159943) expressing attenuated LD clonal population (A-LD) is able to confer protection against the experimental challenge with the virulent LD AG83 parasite. A-LD was also effective in established leishmania infection. The vaccinated animals showed both cell mediated (in vitro T-cell proliferation, and DTH response) and humoral responses (Th1 type). These results demonstrate the potential of the attenuated clones as an immunotherapeutic and immunoprophylactic agent against visceral leishmaniasis.     

Genetic interaction between Non-MHC T- and B-cell alloantigens in response to rous sarcomas in chickens

Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 6₃ regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line RPRL 100, although these lines are identical for the major histocompatibility B complex. They differ, however, at three independent autosomal loci: Ly-4 and Th-1 determine the surface alloantigens of partly overlapping subsets of T lymphocytes, and Bu-1 determines a surface alloantigen of B lymphocytes. The association of genotypes at these loci with quantitative variation in their ability to regress Rous sarcomas was tested in segregating F₄ generation progeny derived from crosses of lines 100 and 6₃. The Ly-4 and Bu-1 genotypes showed association with Rous sarcoma regression, but the Th-1 genotype did not. Chickens of the Ly-4 ^a/Ly-4 ^a, Bu-1 ^b/Bu-1 ^b and Ly-4 ^b/Ly-4 ^b, Bu-1 ^a/Bu-1 ^a genotypes had a significantly higher regressor ability than the other two double homozygous genotypes. These results indicate that higher regression is associated with (1) interaction between the Ly-4 and Bu-1 loci, and (2) complementation between either the line 6 Ly-4 ^a allele and the line 100 Bu-1 ^b allele, or the line 100 Ly-4 ^b allele and the line 6 Bu-1 ^a allele.     

Rectangular game theory and metabolic response to random changes in environmental states

Rectangular game theory is applied to the response of organisms to random environmental changes: A hypothetical example of the response of a facultative algae to random changes in illumination is analyzed. Two strategies are discussed: Bayes' risk and maximin. It is shown how to detect such strategies in populations. The analysis does not require assumptions about the form of the relationship between metabolic activities and selective advantage, but assumptions about evolutionary optimization are required. The maximin strategy is shown to be related to metabolic homeostasis.     

A mutant of Halobacterium halobium with constitutive production of bacteriorhodopsin

Abstract A purple mutant of Halobacterium halobium was isolated in a previous study. The 'in vitro' absorption spectra of the cells gave a broad shoulder around 570 nm. The amounts of bacteriorhodopsin were high under any growth condition (including aerobic) inhibitory for the wild-type strain. The mutant grew faster under illuminated microaerophilic conditions and showed faster proton extrusion than the wild-type strain. This evidence shows that the mutant has a constitutive bacteriorhodopsin production not influenced by the oxygen concentration in the medium. However, some stimulation by light was found.