Isolation and screening of microorganisms dissolving low-grade rock phosphate

Several yeasts, fungi and bacteria isolated from the rhizosphere of leguminous crops and soils of rock phosphate deposit area were found to solubilize low-grade Mussorie rock phosphate. Of the several yeasts and fungi,Schawanniomyces occidentalis, Aspergillus awamori andPenicillium digitatum were better than others in rock phosphate solubilization. Among bacterial isolates from soils of rock phosphate deposits, Gram-negative motile rods were more effective than Gram-negative non-motile rods in dissolving rock phoshates. The most efficient bacteria were identified as strains ofPseudomonas striata. All the microorganisms acidified the liquid medium but there was no relationship between the rock phosphate dissolved and the decrease in pH of the culture broth.     

Conservation of HLA class I private epitopes in macaques

Fifty mouse monoclonal antibodies (mAb) specific for HLA class I epitopes were compared for their reactivity against two closely related nonhuman primate species, pigtailed macaques (Macaca nemestrina, Mn) and longtailed macaques (M. fascicularis, Mfl), which diverged from the hominoids 23–40 million years ago. An analysis of Nei's genetic identity (I) and distance (D) based on reactivity of all class I-specific mAb showed, as expected, that the macaques are more closely related to each other (1=0.959) than to man (I=0.782 for Mn and 0.859 for Mfl). However, there were clear differences in genetic similarity with respect to certain epitopes. Macaques were most different from each other and from man in expression of heterologous epitopes recognized by the mouse that are not polymorphic among humans. In contrast, the most polymorphic epitopes unique to single HLA alleles, so-called private epitopes, were present in all the species, and neither macaque species could be distinguished from humans, suggesting that certain class I private epitopes may be highly conserved in evolution.[/p]Abbreviations used in this paper D Nei's index of genetic distance - I Nei's index of genetic identity - mAb monoclonal antibodies - Mfl Macaca fascicularis - MHC major histocompatibility complex - Mn Macaca nemestrina - PF phenotypic frequency     

Synergistic activation of granulocyte-macrophage colony-stimulating factor production by IL-1 and IL-2 in murine Th1 cells

Recent reports indicate that murine CD4+ Th1-type cloned T cells are insensitive to IL-1 because specific IL-1R are not detected on these cells and IL-1 does not modulate proliferative responses. However, we have determined that Th1 clones can respond to IL-1, because they function synergistically with IL-2 to induce granulocyte-macrophage-CSF secretion. This response to IL-1 plus IL-2 could be induced by IL-1 alpha or IL-1 beta and by membrane-bound IL-1 on macrophages. However, IL-1R could not be detected, and Th1 cells did not respond to IL-4 in the presence or absence of IL-1, as measured by either proliferation or granulocyte-macrophage-CSF production. Therefore, IL-1 functioned as a cofactor in Th1 cells stimulated with IL-2, but not with IL-4. A possible mechanism whereby IL-1 activates Th1 cells is discussed.