Formation of antigenic determinants

In the cephalosporins, the formation of penicillenic acid equivalents appears difficult and the corresponding intermediates would generate penamaldates (Fig. 10). Furthermore, the presence of a dihydrothiazine ring instead of a thiazolidine ring makes the formation of a penicilloic acid equivalent unlikely and that of a penicillamine analogue impossible (Dewdney 1977). 

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Fig. 5. Formation of antigenic determinants from benzylpenicilloic acid...

Interaction of antigenic determinants on target cells with sensitized T-lymphocytes leading to the activation of such lymphocytes and to the destruction of target cells, possibly through the formation of lymphotoxins and/or of toxic peroxides. 

Investigations of the formation of antigenic and allergenic determinants of benzylpenicil-hn have identified a list of determinants that inclndes the penicUloyl, penidllenate, peni-cUloic acid, peniUoic acid, penamaldate, penicoyl, penicillanyl, and penicillamine stmctnres. 

The nature of the antigenic determinant has been characterized in a male worker with occupational asthma from nickel [415, 416] the antibody recognized Ni2+ bound at the natural Cu2 + /Ni2+ transport site of human albumin. The interpretation was deduced from metal ion blocking experiments and from the good agreement obtained between the pH dependency of the formation of the Ni2 + -albumin complex and the antigen-antibody complex. It was suggested that the antibody interaction depended on a special structural feature of the interaction of Ni2 + with human serum albumin, and perhaps the ability to form an octahedral complex affords one explanation [417]. 

When grown at 25°, mycelia, or conidia mixed with mycelia, produce di-O-rhamnosyl side-chains (see the preceding) that are the main, antigenic determinants, as shown by inhibition experiments with oligosaccharides and rabbit immune serum.131 The response of human sera to the polysaccharide, and the fact that 13C-n.m.r. spectroscopy showed that conidia of S. schenckii form a rhamnomannan similar to the yeast component and different from the di-O-rhamnosylman-nan of hyphae,132 suggest the formation of hyphae in vivo. 

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