SOME EFFECTS OF FORMALDEHYDE ON HORSE ANTIPNEUMOCOCCUS SERUM AND DIPHTHERIA ANTITOXIN, AND THEIR SIGNIFICANCE FOR THE THEORY OF ANTIGEN-ANTIBODY AGGREGATION

Opening the OPK Assay Gatekeeper: Harnessing Multi-Modal Protection by Pneumococcal Vaccines

Pneumococcal vaccine development is driven by the achievement of high activity in a single gatekeeper assay: the bacterial opsonophagocytic killing (OPK) assay. New evidence challenges the dogma that anti-capsular antibodies have only a single function that predicts success. The emerging concept of multi-modal protection presents an array of questions that are fundamental to adopting a new vaccine design process. If antibodies have hidden non-opsonic functions that are protective, should these be optimized for better vaccines? What would protein antigens add to protective activity? Are cellular immune functions additive to antibodies for success? Do different organs benefit from different modes of protection? Can vaccine activities beyond OPK protect the immunocompromised host? This commentary raises these issues at a time when capsule-only OPK assay-based vaccines are increasingly seen as a limiting strategy.

ON THE MECHANISM OF SPECIFIC PRECIPITATION

A study of the precipitability by the appropriate antisera of 34 different haptens, containing from one to six reactive groups, leads to the conclusion that the possibility of framework ("lattice") formation is neither necessary nor sufficient for specific precipitation, but that instead precipitation depends upon the reduction, by mutual neutralization of polar groups of antibody and antigen (or hapten) and mechanical blocking off of polar groups of closely neighboring molecules of antibody, of the solubility of the complex below the point at which it can remain in solution. The decisive factors appear to be the number of polar groups of the antigen (hapten) left free, and the distance separating the different reactive groups, which determines the amount of steric hindrance exerted by one antibody molecule on another. No hypothesis is offered as to how these primary insoluble aggregates unite with each other to produce the larger aggregates which are finally observed.

Protective action of ascorbic acid and sulfur compounds against acetaldehyde toxicity: implications in alcoholism and smoking

Acetaldehyde is a toxic substance common to heavy drinking of alcohol and heavy smoking of cigarettes. It has been implicated thereby in diseases of the cardiovascular, respiratory, and central nervous systems. Protection against acetaldehyde toxicity (i.e. anesthesia and lethality) was studied in rats by oral intubation of test compounds 30-45 minutes prior to oral intubation of a standardized oral LD 90 dose (18 millimoles/kilogram) of acetaldehyde. Animals were monitored for anesthesia (loss of righting reflexes) and lethality for 72 hours. A total of 18 compounds was tested. L-ascorbic acid at 2 millimoles/kilogram (mM/kg) showed moderate protection against anesthesia and marked protection against lethality. Greatest protection against anesthesia and lethality was obtained at 2 m M/kg with each of the following: L-cysteine, N-acetyl-L-cysteine, thiamin-HCl, sodium metabisulfite, and L-cysteic acid. A combination of L-ascorbic acid with L-cysteine, and thiamin-HCl at reduced dose levels (2.0, 1.0 and 0.3 mM/kg, respectively) gave virtually complete protection. A detailed literature review is presented of the rationale and significance of these findings. Our findings could point the way to a possible build-up of natural protection against the chronic body insult of acetaldehyde arising from heavy drinking of alcohol and heavy smoking of cigarettes.

Effect of formaldehyde on the immunochemical and biological activity of staphylococcal enterotoxin B

Staphylococcal enterotoxin B was treated with 0.15 or 0.3% formaldehyde at 37 C and pH 7.3. As early as 8 hr after addition of HCHO, the toxin was unable to precipitate as much antibody from antiserum as untreated toxin; greater amounts of treated toxin were required to reach equivalence and to inhibit precipitation. With increasing time, its reactivity decreased so that at 32 weeks it could precipitate only 20% as much antibody as untreated toxin. When other factors were kept constant, the degree of inactivation increased as the HCHO concentration increased from 0.6 to 1.4%. Treated toxin gave a "reaction of partial identity" by the Ouchterlony double-immunodiffusion technique. The emetic effect of the toxin for the monkey remained essentially unchanged for about 48 hr of treatment, but the amount required to cause death by the intravenous route increased from 25 to over 1,000 mug/kg of body weight. HCHO destroyed the pyrogenic effect for rabbits. The treated toxin remained immunogenic for rabbits even after 4 to 5 weeks of exposure to 0.3% HCHO at 37 C.