Characterization of dermatologic changes in geriatric rhesus macaques.

Nonhuman primates are frequently used for aging studies. We observed a high prevalence of skin disease among a group of geriatric rhesus monkeys (mean age = 25 years; n = 9) used in aging behavioral studies. Gross and histopathologic changes in the skin of these geriatric rhesus were compared with skin from control adult monkeys (mean age = 10; n = 4) and sun-exposed monkeys (mean age = 11; n = 4) to characterize age-related skin changes. Biopsy specimens were taken from four specified skin locations (lateral to bridge of nose, ventral midline, dorsal midline, perineal area) and from additional areas where skin lesions were present. Samples were routinely processed and evaluated by light microscopy. Blood samples were collected and tested for estrogen, thyroid-stimulating hormone, triiodothyronine thyroxine, and cortisol levels. The axilla was swabbed and samples were obtained for bacterial culturing. All nine of the geriatric monkeys had notable dermal lesions, while one of the control monkeys and one of the sun-exposed monkeys had abnormal findings. Major gross findings included increased areas of erythematous skin, wrinkling, focal skin scaling, thinning of hair, foot calluses, and exudative lesions. Histologic skin changes included subacute dermatitis, acanthotic dermatitis, and a lesion resembling an early solar lentigo in the sun-exposed animal. These changes were not associated with hormonal abnormalities or bacterial pathogens. Histologic changes are compatible with nonspecific skin changes observed in elderly humans. This study establishes a baseline of dermatologic changes of the aging rhesus macaque.

Frequency of antigen-specific B cells during experimental ocular Chlamydia trachomatis infection.

Chlamydia-specific antibody-secreting cells have been identified in conjunctiva and draining cervical lymph nodes by an ELISPOT assay in a cynomolgus monkey model of trachoma. These local sites contained numbers of chlamydia-specific B cells that were higher than those in distant inguinal lymph nodes and peripheral blood. The numbers of chlamydia-specific immunoglobulin G-secreting B cells observed were 5 to 57 per 10(6) cells in conjunctiva and 24 to 996 per 10(6) cells in cervical lymph nodes during conjunctival infection or after challenge of immune monkeys with the chlamydial 57-kDa heat shock protein (hsp60). These studies demonstrate a large chlamydia-specific B-cell component in the conjunctiva during ocular chlamydial infection. These results are similar to our findings for chlamydia-specific T-cell responses.

Effective alpha-particle-mediated radioimmunotherapy of murine leukemia.

The specificity, toxicity, and efficacy of alpha-particle-mediated radioimmunotherapy of murine erythroleukemia was assessed by use of tumor-specific monoclonal antibody 103A labeled with 212Bi. Forty % of the injected dose/g tissue targeted to neoplastic spleens within 1 h after i.v. injection. When 212Bi-103A was injected on day 13 of disease, a dose-dependent response was achieved, as measured by a reduction in splenomegaly and absence of liver metastasis. Mice treated with 212Bi-103A on day 8 of disease showed no histological evidence of erythroleukemia on day 22 and survived significantly longer (median, 118 days) than mice treated with 212Bi-control IgG (78 days) or untreated mice (63 days), indicating successful specific radioimmunotherapy.

Chlamydia-specific lymphocytes in conjunctiva during ocular infection: limiting dilution analysis.

The immunopathogenesis of ocular infection with Chlamydia trachomatis can be investigated in the cynomolgus monkey model of trachoma. During ocular infection, both follicles (germinal centers) containing primarily B lymphocytes and a heavy perifollicular T cell infiltrate are observed. Limiting dilution analyses were performed on conjunctival and peripheral blood lymphocytes to quantify the proportion of antigen-specific cells elicited by ocular C. trachomatis infection. The frequencies of chlamydia-specific cells were 10-100 times higher in conjunctiva than in peripheral blood. Similar frequencies were observed during active infection and during the ocular delayed hypersensitivity response elicited in sensitized monkeys by topical challenge with a triton X-100 extract containing the 57 kD chlamydial stress protein. Given the antigen-specific proliferative response, these cells are most likely T lymphocytes. The finding of large numbers of antigen-specific conjunctival lymphocytes at the site of chlamydial infection suggests that they play an important role in the pathogenesis of this potentially blinding disorder.