Human immunoglobulin transgenic mice provide a method of obtaining human monoclonal antibodies (Mabs) using conventional hybridoma technology. We describe a novel strain of human immunoglobulin transgenic mice and the use of this strain to generate multiple high-avidity human sequence IgG kappa Mabs directed against a human antigen. The light chain transgene is derived in part from a yeast artificial chromosome clone that includes nearly half of the germline human V kappa region. In addition, the heavy-chain transgene encodes both human mu and human gamma 1 constant regions, the latter of which is expressed via intratransgene class switching. We have used these animals to isolate human IgG kappa Mabs that are specific for the human T-cell marker CD4, have high binding avidities, and are immunosuppressive in vitro. The human Mab-secreting hybridomas display properties similar to those of wild-type mice including stability, growth, and secretion levels. Mabs with four distinct specificities were derived from a single transgenic mouse, consistent with an extensive diversity in the primary repertoire encoded by the transgenes.

IL-8 is a chemokine that has been implicated in a number of inflammatory diseases involving neutrophil activation. HuMab 10F8 is a novel fully human mAb against IL-8, which binds a discontinuous epitope on IL-8 overlapping the receptor binding site, and which effectively neutralizes IL-8-dependent human neutrophil activation and migration. We investigated whether interference in the cytokine network by HuMab 10F8 might benefit patients suffering from palmoplantar pustulosis, a chronic inflammatory skin disease. Treatment of patients with HuMab 10F8 was well tolerated and significantly reduced clinical disease activity at all five endpoints, which included a ≥50% reduction in the formation of fresh pustules. IL-8 neutralization was monitored at the site of inflammation by assessing exudates of palmoplantar pustulosis lesions. HuMab 10F8 sequestered IL-8 in situ, as observed by rapid dose-dependent decreases of IL-8 concentrations immediately following Ab infusion. These data demonstrate a critical role for IL-8 in the pathophysiology of palmoplantar pustulosis. HuMab 10F8 is capable of interrupting IL-8 activity in vivo and represents a candidate for treatment of inflammatory diseases and other pathological conditions associated with IL-8 overproduction.

SUMMARY Evidence was obtained by the use of alternate semithin-thin serial sections for light and electron microscopy that the I cell is the source of CCK-PZ. The antibodies used were raised to a synthetic fragment of the mid part (9-20) of the (1-33) CCK-PZ molecule, and were thus free from any contamination with cross-reacting subpopulations of antibodies that might bind to gastrin.

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The recA gene of Aquaspirillum magnetotacticum has been isolated from a genomic library and introduced into a recA mutant strain of Escherichia coli K12. The cloned gene complemented both the recombination and DNA repair deficiency of the host and its protein product promoted the proteolytic cleavage of the LexA protein. A protein whose molecular weight is similar to that of the RecA protein of E. coli was associated with the cloned sequence.