OspC is a well-characterized, highly immunogenic B. treatment. Not every individual responded to BBK32, but anti-DbpA IgG levels were uniformly high and remained elevated for all those animals. All responded to OppA-2, with a decline posttreatment that was slow and incomplete. This is the first demonstration of OppA-2 antigenicity in nonhuman primates. The combination of DbpA, OspC, OspA, and OppA-2 with the C6 diagnostic peptide has the potential to detect contamination throughout all disease phases. INTRODUCTION The etiologic agent of Lyme disease, antigens. Detection of antibodies instead of antigens is usually necessitated by the absence of detectable spirochetes in the bloodstream once the organism has disseminated. Detection of the bacteria or bacterial antigens from blood or skin biopsy specimen is usually both invasive and of relatively low sensitivity (2). Antigen can sometimes be detected in urine and cerebrospinal fluid, but these assessments are neither reliable nor recommended (45). Two of the most commonly used assessments for diagnosis in North America are (i) the two-tier test, which includes an enzyme-linked immunosorbent assay (ELISA) and Western blotting using antigen derived from whole-cell lysates, Rabbit Polyclonal to ME1 and (ii) the C6 test, which detects antibodies to a specific peptide within a conserved region of the antigen VlsE (5, 30, 32). The C6 test has also been used experimentally for evaluation of treatment efficacy (36, 37). While the two-tier and C6 assessments are suitable for a majority of patients, neither is completely specific or sensitive enough to diagnose all patients. The C6 test, for instance, is usually more sensitive for human patients with early or late disseminated disease than for patients in the localized phase (5, 16). While the C6 peptide is usually highly NCT-502 conserved, other ELISA and Western blotting assessments utilize whole-cell lysates or recombinant proteins from one species/strain/isolate, despite the enormous potential for antigenic variability that can preclude acknowledgement by antibody. Western blotting will also specifically detect antibodies that identify the antigen in a fully or partially denatured state, so those antibodies that target conformational epitopes are missed. Furthermore, the potential for patient serum cross-reactivity with antigens shared with other bacteria has led to stringent diagnostic criteria that can confound Western blot interpretation and thus hinder accurate diagnosis (6). Along with C6 or VlsE, several other proteins that are known to elicit antibody responses in natural infections and have been incorporated into immunoblotting-based diagnostics include outer surface protein C (OspC) (44), the fibronectin-binding protein BBK32 (29), decorin-binding protein A (DbpA) (18), flagellar protein, FlaB, and outer surface protein A (OspA). The temporal NCT-502 induction and magnitude of the B cell response to each of these, characterized primarily in mice, are different. OspC, for example, is highly immunogenic, contains antigenic regions that vary among isolates, and is expressed early in contamination and then repressed at the introduction of humoral immune responses (28). Antibodies (IgM and IgG) to OspC often appear early in contamination (24, 34). DbpA is usually expressed within the first few days of contamination and continues postdissemination, so the antibody response can remain, even in late disease (18). FlaB is usually constitutive and immunogenic but holds the potential to be detected by cross-reactive antibodies from other bacterial species, especially when denatured as in Western blotting (17). OspA is usually expressed when is in the tick, but its expression is usually repressed as the spirochetes traverse to the host during tick feeding (40). However, studies indicate that expression of OspA and subsequent antibody responses may return during long-term infections NCT-502 in Lyme arthritis patients (3, 26). As a model for human Lyme disease, cultured late log-phase strain B31, isolate 5A19 (39), as follows: two subcutaneous 1.0-ml injections and one intradermal 0.1-ml injection, each containing 1 108 organisms diluted in sterile Hanks balanced salt solution (HBSS), for a total inoculum of 3 108 organisms. At 4 months postinoculation (p.i.), three of the five animals received antibiotic treatment consisting of one 50-mg tablet of doxycycline (Bio-Serv) twice daily for 28 consecutive days. This dose corresponded to 12 mg/kg of body weight/day to ensure that an effective blood level was achieved. Blood was collected at the following time points: 0, 2, 6, 10, 14, 16, 18, 22, 26, 28, 34, 40, and 47 weeks p.i. Strain JD1-infected animals. Briefly, 24 rhesus macaques (Chinese origin) were each given an inoculation of 3.2 108 spirochetes of the JD1.