Immune traits

Birkhead, T. R., Fletcher, F., and Pellatt, E. J. 1998. Sexual selection in the zebra finch Taeniopygia guttata Condition, sex traits and immune capacity. Behav. Ecol. Sociobiol. 44 179-191. 

A number of attempts have been made to select on nematode immune-related traits. Lines of Heligmosomoides polygyrus have been selected in hosts with different histories of previous exposure (naive, once previously exposed, or multiply previously exposed). This resulted in parasite lines that differed in fitness when tested in semi-immune animals, with the lines selected in the hosts with greatest previous exposure surviving best and... 

Taken as a whole, these observations show that parasite lines differ in an immune-dependent manner in their infection/expulsion kinetics. Furthermore, there is heritable variation in survival and fecundity in previously exposed hosts and quantitative variation in the immune response that selected parasite lines elicit. Again, taken as a whole, these observations have the necessary corollary that variation in these traits exists not only in laboratory-maintained isolates but also in helminth species in nature. The phenotypes under consideration here (infection/expulsion kinetics, survival, fecundity) are multifactorial life-history traits. Understanding the basis of variation in the components and interplay of these complex, immune-responsive phenotypes must be of crucial relevance to understanding the immunology of infections of parasitic nematodes. This is of particular relevance in view of current attempts to develop immunological methods of nematode control. 

The third example considered the interaction of life-history traits (survival rates, fecundity, immunogenicity) with an environmental factor specific to parasites, namely the host immune system. Here phenotypic diversity in response to environmental conditions (host immunity) is not so readily apparent. To observe phenotypic diversity, different parasite lines need to be compared in their kinetics of infection and, to show immune-dependence, these must be complemented by control experiments in immunosuppressed hosts. Experiments seeking to select on this diversity... 

Marsland, A.L. et al., Associations between stress, trait negative affect, acute immune reactivity, and antibody response to hepatitis B injection in healthy young adults, Health Psychol., 20, 4, 2001. 

Thus, together these studies suggest that the oxidative burst machinery has evolved before the crown diversification of eukaryotes (Baldauf 2003) to provide marine algal lineages with natural and induced innate immunity mechanisms. These play a role similar to the HR in terrestrial plants infected by incompatible pathogens and they share important common traits with the innate immunity response of mammalian phagocytes. 

The origins of diabetes mellitus are still being investigated. There is a familial trait—certain histocompatability phenotypes and perhaps other non-HLA genes are more frequently displayed by juvenile diabetics than others. Viral infections in childhood may precipitate immune responses which damage the P islet cells. Other types of diabetes, such as that shown by middle-aged or older patients, have different causes and can often be controlled by appropriate diet. 

Not all hereditary traits follow the Mendelian patterns expected for chromosomal genes. Some are inherited directly from the maternal cell because their genes are carried in the cytoplasm rather than the nucleus. There are three known locations for cytoplasmic genes the mitochondria, the chloroplasts, and certain other membrane-associated sites.285 286 An example of the last is found in "killer" strains of yeast. Cells with the killer trait release a toxin that kills sensitive cells but are themselves immune. The genes are carried in double-stranded RNA rather than DNA, but are otherwise somewhat analogous to the colicin factors of enteric bacteria (Box 8-D). Similar particles (kfactors) are found in Paramecium.287... 

Bertrand IL, Rousset H, Queneau P, Ollagnier M. Thyroidite auto-immune, une complication rare du traite-ment a la D-penicillamine. [Autoimmune thyroiditis. A rare complication of treatment with D-penicillamine.] Therapie 1981 36(3) 333-6. 

Mechanisms to control parasitic protozoa are similar to those utilized for other infectious agents they can be divided into non-specific mechanism(s) and specific mechanism(s) involving the immune system. The best studied non-specific mechanisms include those that affect the entry of parasites into the red blood cell. The sickle cell haemoglobin trait and lack of the Duffy factor on the erythrocyte surface make the red cell more resistant to invasion by Plasmodium. These traits are commonly found in populations from malaria-endemic regions. A second example of a non-specific factor is the presence of trypanolytic factors in the serum of humans which confer resistance to T. brucei, Although nonspecific factors can play a key role in resistance, usually they work in conjunction with the host s immune system. 

ADA deficiency and PNP deficiency are two autosomal recessive traits that cause immune system dysfunction. The reactions catalyzed by ADA and PNP are shown in Figure 27-21. Both enzymes function in conversion of adenosine and deoxyadenosine to hypoxanthine. PNP is... 

The simple manipulations required to separate free antibody or antigen from immune complexes immobilized non-covalently on plastic solid phase is probably the most important reason for the rapid increase in popularity of EIA. Desired traits of the solid phase are (i) high capacity for binding immunoreactants (high surface/ volume ratio) (ii) possibility of immobilization of many different immunoreactants (iii) minimal dissociation (iv) negligible denatura-tion of immobilized molecule and (v) orientation of immobilized antibody with binding sites towards the solution and the Fc to the solid phase (e.g.. Section 13.2.2). 

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