Determinación de IgA salival contra la gp120 en pacientes VIH+ y VIH- / Determination of salivary IgA against gp120 in HIV+ and HIV- patients

La producción de inmunoglobulina A (sIgA) es uno de los mecanismos a través de los cuales el sistema inmune humoral protege a las superficies mucosas, inhibiendo la adherencia de patógenos y neutralizando la acción de los virus. Estudios realizados con individuos VIH+ han demostrado que la IgA se une a las glicoproteínas de la envoltura, gp120 ygp41, del virus VIH-1. Objetivo: el propósito de este trabajo fue detectar los niveles de IgA salival contra 50 péptidos que representan la gp120 de la envoltura del virus VIH-1 y están constituidos por secuencias de 20 aminoácidos. Materiales y métodos: se utilizó la técnica de inmunoensayo enzimático (ELISA) con saliva total no estimulada de 24 sujetos, que fueron divididos en 3 grupos: 9 VIH+CD4>200 mm3; 10 VIH+CD4<200 mm3 y 5 VIH-. Los péptidos utilizados cubrieron el espectro de 510 aminoácidos de la gp120. Resultados: los resultados demostraron que los niveles de IgA específica fueron significativamente mayores (p=0.0001) en el grupo VIH+ que en el grupo VIH-. No se observaron diferencias significativas entre los grupos VIH+CD4>200 mm3 y VIH+CD4<200 mm3. No se observó correlación significativa entre el contaje CD+ y las respuestas de IgA. Los péptidos con mayor número de respuestas en el grupo VIH+ correspondieron a las regiones C1, V2 y C3. Conclusiones: los niveles de IgA salival observados en este estudio no mostraron variabilidad en relación con el contaje de células CD4+ y los péptidos que provocaron mayores respuestas de anticuerpos correspondieron a regiones con poca variabilidad sobre la cubierta del virus

Expression of MHC Class II, CD70, CD80, CD86 and pro-inflammatory cytokines is differentially regulated in oral epithelial cells following bacterial challenge.

Oral epithelium may play a regulatory role in local immune responses when interacting with bacteria. The present study was undertaken to investigate the effects of selected bacterial pathogens found in periodontal and endodontic infections on oral epithelial cells. Expression of cell surface molecules (major histocompatibility complex (MHC) Class II, CD54, CD70, CD80 and CD86) and secretion of inflammatory cytokines (interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha) in response to selected bacterial challenge were examined on an immortalized oral epithelial cell line, HOK-18A and a skin epithelial cell line, HaCaT. Actinomyces viscosus, Actinomyces israelii, Fusobacterium nucleatum lipopolysaccharide (LPS) or primary human periradicular exudate from a granuloma were co-cultured with epithelial cells for 4 or 24 h. Subsequently, cell surface expression of MHC Class II, CD54, CD70, CD80 and CD86, along with pro-inflammatory cytokine levels were determined using flow cytometry, ELISA and RT-PCR. Results indicated that the selected oral bacteria have greater effects on oral versus skin epithelial cells. F. nucleatum increased MHC Class II and CD54 (ICAM-1) cell surface expression on HOK-18A and HaCaT cells. A. israelii also had enhancing effects on the expression of CD54 and MHC Class II. A. israelii and LPS induced a 2.8-fold (P < 0.001) and 4.4-fold (P < 0.005) TNF-alpha secretion, respectively, while F. nucleatum and LPS induced a 10-fold (P < 0.0004) and 6-fold (P < 0.01) IL-1beta secretion, respectively by HOK-18A. Interestingly, CD70, CD80, and CD86 were generally decreased upon bacteria and LPS challenge on HOK-18A. The effects of increased MHC Class II and decreased CD70 were also evident with challenge of human periradicular exudate on HOK-18A. The implications of the study are unique in that oral epithelial cells may play both activating and inhibitory roles in the host immune response towards infection by oral bacteria. We introduce a concept of 'dormancy' where the differential expression of key cell surface antigens on oral epithelial cells may keep the recruited immune effector cells in a state of unresponsiveness, thus contributing to the long term quiescent period observed in many periodontal and endodontic lesions.

Salivary immunoglobulin A antibodies to gp41 in human immunodeficiency virus-seropositive patients: lack of correlation with disease progression.

Mucous membranes are the main route of transmission of human immunodeficiency virus (HIV). Interestingly, some viral inhibitory activities have been found in saliva. The purpose of this study was to determine the level of salivary immunoglobulin A (IgA) antibodies to gp41 in HIV+ patients at various disease stages to identify whether gp41 was able to induce vigorous humoral responses. Unstimulated saliva samples were obtained from three groups of subjects (n=37): group A (HIV-), group B (HIV+, CD4+ <200/mm3), and group C (HIV+, CD4+ >200/mm3). IgA antibody levels to purified gp41 were determined by enzyme-linked immunosorbent assay (ELISA). Western blot analyses were performed using HIV+ saliva to confirm IgA reactivity to gp41. ELISA demonstrated that HIV+ subjects had higher IgA antibody to gp41 than HIV- individuals. No significant differences were noted between HIV+, CD4+ <200/mm3 and CD4+ >200/mm3 subjects. High (81.25%) IgA reactivity to gp41 was demonstrated by Western blotting of saliva from all HIV+ individuals. In conclusion, gp41 responses are important in the HIV disease process, as indicated by the high IgA levels and gp41 reactivity in saliva of HIV+ patients.

Evaluation of immunologic markers in cervicovaginal fluid of HIV-infected and uninfected women: implications for the immunologic response to HIV in the female genital tract.

We analyzed 21 cervicovaginal lavage (CVL) specimens from 19 women participating in the Women's Interagency HIV Study to characterize levels of antibody, cytokine, and complement and to determine associations between these levels and stage of the menstrual cycle, HIV status, and the presence of concurrent genital infection and genital dysplasia. Sixteen samples were collected from HIV-infected women and five from high-risk HIV-seronegative women. CVL fluid was assayed for levels of IgG, secretory IgA (s-IgA), interleukin 2 (IL-2), IL-10, IL-6, tumor necrosis factor alpha (TNF-alpha), IL-1beta, interferon gamma (IFN-gamma), C3, C1q, and C4. Women with HIV were more likely to have cervicovaginal dysplasia (9/16 vs. 0/5; p = 0.027) but were not more likely to have concurrent vaginal infection (10/16 vs. 2/5; p = 0.38). Antibody, cytokine, and complement were detectable in all samples, although not all samples had measurable IL-10, C3, or C4. HIV-infected women demonstrated a trend toward higher levels of IFN-gamma than did uninfected women (p = 0.098); no differences were noted in other parameters. HIV-infected women with vaginal infections had significantly higher CVL levels of IgG (p = 0.023) and IFN-gamma (p = 0.02) than did HIV-infected women without genital infections. HIV-infected women with cervicovaginal dysplasia were found to have higher levels of IL-1beta (p = 0.045) and IFN-gamma (p = 0.039) than those without. Analysis of the HIV-infected cohort by CD4 cell count revealed higher levels of IgG and IFN-gamma in CVL from women with lower CD4 cell counts, although these differences were not statistically significant. Higher levels of proinflammatory cytokines in CVL fluid of women with genital infection or cervicovaginal dysplasia may affect local HIV replication and may influence the risk of acquisition or transmission of HIV for women with these underlying conditions.

Cutaneous manifestations of disseminated cryptococcosis.

Five patients with disseminated cryptococcosis had lesions on the extremities resembling cellulitis, which evolved into areas of blistering and ulceration in three patients. All had underlying disease and were medically immunosuppressed. Disseminated cryptococcosis appears to present with cellulitis or herpes-like vesiculation more commonly than is currently appreciated. India ink preparations of aspirates from areas of cellulitis or Tzanck preparations from blisters may show characteristic organisms, and make possible an immediate diagnosis of cutaneous cryptococcosis. If cutaneous infection is confirmed by performing biopsies and growing cultures, dissemination must be presumed and the patient treated with a full course of systemic antifungal therapy. With increasing awareness of cutaneous involvement, some cases of disseminated cryptococcosis will be diagnosed sooner, leading to earlier therapy and improved prognosis.