TABLE 1.

Anti-A. marginale MSP-2 IgG1 and IgG2 antibody titers

AnimalaTiterb
IgG1IgG2
Expt 1
    Control MAb
        53432,000<10
        84232,000<10
    Mean ± SEM32,000 ± 0 <10 ± 0
    Anti-CD4 MAb
        84332,000<10
        84432,000<10
    Mean ± SEM32,000 ± 0 <10 ± 0
Expt 2
    Control MAb
        537128,0004,000
        86564,0001,000
    Mean ± SEM96,000 ± 32,0002,500 ± 1,500
    Anti-CD4 MAb
        53516,000<10
        86016,000<10
    Mean ± SEM16,000 ± 0 <10 ± 0
  • a Calves 534 and 842 (experiment 1) and 537 and 865 (experiment 2) were thymectomized and treated with a subclass-matched control MAb. Calves 843 and 844 (experiment 1) and 535 and 860 (experiment 2) were thymectomized and treated with an anti-CD4 MAb. All calves were infected with A. marginale, and isotype-specific antibody responses were assessed 8 weeks postinfection following resolution of acute infection.

  • b Sera were diluted 1:10 to 1:128,000 and were tested for reactivity against A. marginale Florida homogenate on Western blots. The titer is defined as the reciprocal of the highest dilution giving a positive signal on the blots. <10, no reaction at a dilution of 1:10 or higher.