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The role of phosphorus (P) in numerous important biological structures, coupled with the observation that P-content of many insect foods is disproportionately low, suggests that P may be a critical nutrient for growing insects — however, the few studies examining the effects of dietary P on insect performance have generally found only weak relationships. This mismatch may be reconciled by understanding the physiological mechanisms by which insects handle P. Here we describe P processing by larvae of Manduca sexta. When given un-manipulated leaves of a common host plant, Datura wrightii, fifth-instar larvae retained about 85% of P consumed; when given P-enriched leaves larvae retained only 25% of P consumed. Analysis of gut concentrations of P at four sites along the digestive tract, and in leaves and feces, indicates that the rectum is the primary site of P transport between the gut and body and that differences in P retention may be accounted for by differential rates of rectal P transport. Larvae given P-enriched leaves also showed an eightfold increase in the concentration of P in the hemolymph, primarily as α-glycerophosphate — but only a 12% increase in the concentration of P in body tissues, suggesting that hemolymph plays a central role in storage and buffering of P. [ABSTRACT FROM AUTHOR]

Summary Background Understanding of humoral immune responses in tuberculosis (TB) is gaining interest, since B-cells and antibodies may be important in diagnosis as well as protective immune responses. High-content peptide microarrays (HCPM) are highly precise and reliable for gauging specific antibody responses to pathogens, as well as autoantigens. Methods An HCPM comprising epitopes spanning 154 proteins of Mycobacterium tuberculosis was used to gauge specific IgG antibody responses in sera of TB patients from Africa and South America. Open source software for general access to this method is provided. Results The IgG response pattern of TB patients differs from that of healthy individuals, with the molecular complexity of the antigens influencing the strength of recognition. South American individuals with or without TB exhibited a generally stronger serum IgG response to the tested M. tuberculosis antigens compared to their African counterparts. Individual M. tuberculosis peptide targets were defined, segregating patients with TB from Africa versus those from South America. Conclusions These data reveal the heterogeneity of epitope-dependent humoral immune responses in TB patients, partly due to geographical setting. These findings expose a new avenue for mining clinically meaningful vaccine targets, diagnostic tools, and the development of immunotherapeutics in TB disease management or prevention. [ABSTRACT FROM AUTHOR]