CF Antibody Research Articles

Immunological relationship between infectious cough in horses and human influenza A.

High CF antibody titers against the soluble (CAM) antigen of influenza A have been demonstrated in a large proportion of sera from horses suffering from an epizootic febrile cough. Significant rises in titers were found in 4 out of 5 cases in which acute phase serum samples could be obtained. The hemagglutination-inhibition test failed to reveal the presence of significant amounts of strain-specific antibodies against several known influenza A virus strains.

Stability of mumps antibody and antigen at various temperatures.

Summary1. The CF antibodies of pooled mumps antisera were stable for 2 months at −15 °C, and for 30 minutes at 60°C. 2. Sub-freezing temperatures had a markedly deleterious effect on the CF titer of mumps vaccine; temperatures above freezing had little effect; samples stored at 5°C for 3 years showed no drop in titer. After as many as 10 cycles of freezing and thawing, the CF titer of the vaccine remained unchanged. 3. Vaccine which had lost its CF antigen was able to stimulate the production of CF antibodies in guinea pigs provided Freund's adjuvant was used; however, the order of response was approximately 1/5 that produced by the same vaccine with the CF antigens intact. 4. The significance of these observations is discussed in relation to mumps vaccination studies.

Homotypic complement-fixing antibody in monkeys infected with type 2 poliomyelitis virus by the oral route.

CF tests with Type 2 poliomyelitis antigen (MEF1) were performed on the pre- and postinfection sera of 20 cynomolgus monkeys which developed paralytic, non-paralytic, or inapparent infection following oral administration of a Type 2 strain of virus (Y-SK). All the monkeys developed neutralizing antibody, and 17 developed CF antibody in an original serum dilution titer of 1:4 or greater. The 3 monkeys which did not develop this level of CF antibody were in a group of 7 which died within 8 days after onset of paralysis. The CF titers were as high at 2 to 6 days after onset of paralysis in the other 4 moribund or dead monkeys as in the surviving animals tested 4 weeks after the first dose of virus and the CF titers were of the same order of magnitude in the groups with paralytic, non-paralytic, or inapparent infection. The Type 2 poliomyelitis CF titers developed in monkeys as a result of infection with homotypic virus were not greater than those found in human beings infected with heterotypic Type 1 poliomyelitis strains.

COMPLEMENT FIXATION TEST IN TOXOPLASMOSIS AND PERSISTENCE OF THE ANTIBODY IN HUMAN BEINGS

An antigen prepared from toxoplasma-infected chorioallantoic membranes, improved by centrifugation at 13,000 r.p.m. for one hour which removed a nonspecific component capable of fixing complement with certain normal sera, proved to be the preparation of choice for toxoplasmic CF tests. Though it was possible to prepare an antigen of similar potency from mouse brain, the yield from one egg is at least 10 times more than from one mouse. The peritoneal exudate of mice freed of Toxoplasma and cells contains eight times as much antigen per unit volume as a 20% extract of mouse brain or chorioallantoic membranes, but its anticomplementary properties, which cannot be removed by high speed centrifugation, can be eliminated only by extensive dilution. The highly centrifuged and diluted peritoneal exudate, however, still contains a component which fixes complement with certain normal human sera. Sixteen children, aged 5 weeks to 11 years, with clinically recognized congenital toxoplasmosis and 17 mothers, with inapparent or clinically unrecognized infection except for having given birth to children with proved toxoplasmosis, were investigated for the presence and persistence of CF antibodies. With the improved antigen and the standardized method that was used, even titers of 1:2 and 1:4 were significant and invariably associated with toxoplasmic neutralizing antibody. The sera of all 17 mothers gave positive CF tests with titers ranging from 1:4 to 1:64, the higher titers predominating during the first two years after the delivery of the infected child. The sera of 14 of the 16 children (87.5%) with clinical evidence of congenital toxoplasmosis, confirmed by neutralization tests, gave positive CF tests with titers ranging from 1:2 to 1:128, the higher titers again predominating during the first two years after birth. One of the negative results, in a 5 week old child with active infection who died three days after the serum was obtained, was associated with a high (1:4,096) dye test titer for neutralizing antibody in its own serum, and a similar dye test titer (1:4,096) and a CF titer of 1:32 in the serum of its mother. The other negative result, in a 7 year old child with a dye test titer of 1:16, is believed to represent an instance of disappearance of CF antibody after an interval of seven years. Not one serum obtained from 24 children with congenital ocular or neurologic disturbances or both, not due to toxoplasmosis, gave a positive CF test with the toxoplasmic antigen; however, among 20 of their mothers, there were four sera with titers of 1:2, 1:2, 1:8 and 1:16. Toxoplasmic CF antibody can persist for at least six years, and in some instances even longer, in individuals with clinically recognized as well as inapparent or clinically unrecognized infections. Since at least seven of the mothers, who gave birth to children with congenital toxoplasmosis, subsequently gave birth to normal children at a time when the CF antibody titers in some of them were still high (32, 32, 32, 16, 8, 4, 4), it is clear that this antibody can persist in individuals in whom the infection has been eradicated or suppressed sufficiently to prevent its congenital transmission.

A Survey of Bovine Salmonellosis in Mid and West Wales

The serological responses to live Salmonella dublin vaccine was assessed in three groups of calves; three-day-old colostrum-deprived (3DO C−), three-day-old colostrum-fed (3DO C+) and three-month-old (3MO), by the following tests; serum agglutination test (SAT), indirect haemagglutination test (IHA), complement-fixation test (CFT) and antiglobulin test (AGT).Serological activity was detected by all the tests in the 3MO calves. In the 3DO C+ calves no serological activity was detected by either the somatic SAT or IHA but low levels of CF and somatic AGT antibodies were produced. In 3DO C− calves serological activity, often at low levels, was detected by all the tests except the somatic SAT. High levels of flagellar agglutinins were detected in both groups of 3DO calves.It was concluded that with the exception of the flagellar SAT the tests were affected by the age of the calf and in 3DO calves also by the presence of colostral antibodies. However, the use of the SAT in 3MO calves would provide an indication as to the potency of salmonella vaccines.