The business of developing antibacterials.

Although some dazzling technical approaches have fallen short, dozens of small companies and a few major pharmas seek new products for this medically crucial, modest-growth market.

Generation and iterative affinity maturation of antibodies in vitro using hypermutating B-cell lines.

We show that iterative antigen-mediated selection of B-cell lines that constitutively hypermutate their immunoglobulin V genes during culture can be exploited to generate antibodies in vitro. From Ramos, a hypermutating human B-cell line expressing IgM of unknown specificity, we derived descendants that exhibit stepwise improved binding to streptavidin. Binding is initially conferred by mutations in complementarity-determining regions (CDRs), but maturation is due to strategic framework mutations. A more powerful system is provided by a hypermutating chicken B-lymphoma line, owing to its rapid proliferation, high rate of mutation accumulation, and genetic tractability. Starting from a single cell, we selected parallel lineages of derivatives, making mutated antibodies of increasing affinity to independent test antigens. Selection is initiated at an exceedingly low affinity threshold, but antibodies can be delivered with nanomolar affinities. The strategy could prove useful for in vitro generation of antigen-specific monoclonal antibodies and may be extendable to the maturation of other protein-ligand interactions.

Immunoglobulin preparations for intravenous administration. A review of their biologic activities and comparison of various preparation methods.

Substitution therapy with human immunoglobulin preparations is well established in disorders of primary or secondary deficiencies of humoral immunity. However, modifications of the immunoglobulins are required to achieve tolerance for the preferred intravenous route of administration. Several procedures are employed by different commercial suppliers of immunoglobulins, and from the literature it appears that various important biologic functions, e.g., opsonic activity, complement fixation, and Fc-receptor function, are subject to alterations during the preparation. The best preservation of such activity, when assessed in vitro, is obtained with polyethylene glycol precipitation or DEAE-Sephadex fractionation, whereas enzymatic or chemical treatment can potentially reduce the biologic activity. It is recommended that immunoglobulin preparations be evaluated in vitro for intact biologic function before being given to immunodeficient patients.

[Opsonizing activity of human immunoglobulin preparations for intravenous use (IVIG)]. / Aktywnosc opsonizujaca preparatów ludzkich immunoglobulin do stosowania dozylnego (IVIG).

It was shown that all the examined immunoglobulin preparations (IVIG) enhance growth of opsonization of S. aureus, S. epidermidis, E. coli which was studied using the chemiluminescence method. However, no opsonization growth was observed of P. aeruginosa rods with the participation of IVIG (except for Sandoglobulin and the specific immunoglobulin Pseudomonas). We assume that such a result was due to the P. aeruginosa strain's susceptibility to lysis factors of the human serum used in the experiment as the complement source. It was confirmed that phagocytosis with the participation of IVIG measured by the chemiluminescence test requires the presence of a complement. The bactericidal test showed that all IVIG preparations, Pentaglobin in particular, are bactericidal and active against P. aeruginosa. Basing on the results obtained, we believe that the biological activity of the Polish preparation is comparable with the investigated IVIG preparations from foreign firms.