Novel nasal secretion collection method for the analysis of allergen specific antibodies and inflammatory biomarkers.

BACKGROUND: The analysis of immunological markers in nasal secretions provides valuable information for studying nasal mucosa diseases and monitoring immunotherapy and immunity to vaccines administered locally. However, the concentration of biomarkers is highly variable in nasal secretions because of the diversity of collection methods. A nasal secretion collection device was developed to increase detectability of the assay, standardize the sampling technique, eliminate unknown dilution factor, and minimize analyte loss during the sample processing. OBJECTIVE: To develop and demonstrate the performance characteristics of a novel nasal secretion collector and its advantages over nasal lavage techniques. METHODS: Characteristics of absorption and recovery of the liquid or proteins by different types of polyurethane foam were evaluated. The concentration of immunoglobulins, inflammatory mediators and allergen specific antibodies was comparatively measured in nasal secretions collected by the novel nasal secretion collector and nasal lavages. RESULTS: The concentrations of cytokines, eosinophil cationic protein, and tryptase in nasal secretions obtained by the nasal secretion collector were at least 8-fold higher than those tested in nasal lavages. Furthermore, the levels of immunoglobulins and the grass/weed pollen allergen specific antibodies were 6- to 290-fold increased when the nasal secretion collector was used. The nasal secretion collector was easy to use, non-invasive, and caused minimal discomfort to subjects during sampling. CONCLUSION: A novel nasal secretion collector shows a significantly higher detectability and reproducibility than nasal lavages for analyzing immunological markers in nasal secretions. CLINICAL IMPLICATION: The nasal secretion collector represented an approach for collecting nasal secretions and can be applied for routine evaluations of nasal immune responses induced by mucosal vaccinations or infections, inflammations and therapeutic interventions.

A novel adjuvant for mucosal immunity to HIV-1 gp120 in nonhuman primates.

The development of a safe and effective mucosal adjuvant is a crucial step toward a mucosal HIV/AIDS vaccine. This study seeks to determine the promise of a nontoxic mutant of cholera toxin (mCT; E112K) as a mucosal adjuvant in nonhuman primates. HIV-1 gp120 was nasally administered together with mCT E112K or native CT (nCT) as adjuvant on five to six occasions over a 6- to 8-wk period to groups of four rhesus macaques and alone to two monkeys that acted as controls. Macaques given nasal gp120 with either mCT E112K or nCT showed elevated gp120-specific IgG and IgA Ab responses with virus-neutralizing activity in both their plasma and mucosal external secretions, as well as higher numbers of gp120-specific IgA Ab-forming cells in their mucosal and peripheral lymphoid tissues and of IL-4-producing Th2-type CD4-positive (CD4(+)) T cells than did controls. Even though significant mucosal adjuvanticity was seen with both mCT E112K and nCT, neuronal damage was observed only in the nCT-treated, but not in the control or mCT E112K-treated groups. These results clearly show that mCT E112K is an effective and safe mucosal adjuvant for the development of a nasal HIV/AIDS vaccine.

Vaccination in humans generates broad T cell cytokine responses.

In recent years, the quantification of T cell responses to pathogens or immunogens has become a common tool in the evaluation of disease pathogenesis or vaccine immunogenicity. Such measurements are usually limited to enumerating IFN-gamma-producing cells after ex vivo stimulation with Ag, but little is known about the phenotype or complete functional repertoire of the Ag-specific cells. We used 12-color flow cytometry to characterize Ag-specific T cells elicited by vaccines or natural infection to determine lineage and differentiation status as well as the capacity to produce four cytokines (IFN-gamma, TNF-alpha, IL-2, and IL-4) and a chemokine (MIP1beta). As expected, responding cells had a typical memory phenotype; however, the cytokine profiles associated with the responses were highly complex. The pattern of cytokine coexpression in response to specific Ags was a skewed subset of the complete repertoire (revealed by polyclonal stimulation). We found significant differences in the patterns of cytokines elicited by vaccination (where IFN-gamma was by far a subdominant response) vs natural infection; in addition, there was fairly significant intersubject variation. Our findings illustrate the limitation of the evaluation of immune responses using single functional measurements (such as IFN-gamma); in fact, it is likely that sensitive evaluation of Ag-specific T cells will require the coordinate measurement of several cytokines. The presence and variability of these complex response profiles introduce the possibility that selective functional expression patterns may provide correlates for vaccine efficacy or disease progression.

Effects of ovarian steroids on immunoglobulin-secreting cell function in healthy women.

To determine the effect of the ovarian hormone cycle on immunity, immunoglobulin-secreting cell (ISC) frequency and lymphocyte subsets were examined in the blood of healthy women. We found that immunoglobulin A (IgA)-secreting cells (IgA-ISC) were fourfold more frequent than IgG-ISC in peripheral blood mononuclear cells (PBMC). Further, the ISC frequency in PBMC was highest (P < 0.05) during the periovulatory stage of the menstrual cycle. Thus, endogenous ovarian steroids regulate the ISC frequency and this may explain why women are more resistant to viral infections and tend to have more immune-mediated diseases than men do.

Anti-HIV and -SIV immunity in the vagina.

Most HIV infections worldwide are transmitted through heterosexual contact. In order to develop vaccination strategies, the basic biology of the immune system in female reproductive tract and the full range of vaginal immune responses that occur during natural HIV infection must be understood. The cervicovaginal mucosa contains a complete set of immune cells, including antigen-presenting cells, CD4+ and CD8+ T cells, and B cells. The CVS of HIV-infected women and SIV-infected female rhesus macaques contain variable levels of antiviral antibodies. Some of this variation is due to the effects of female ovarian hormone cycle. IgG antibodies make up the bulk of the antiviral antibody response. However, IgA antibodies are present at lower levels. HIV/SIV-specific CD8+ cytotoxic T lymphocytes are present in the cervicovaginal mucosa of infected women and rhesus macaques. A vaccine that can elicit strong antiviral immunity may provide protection for hetorosexual HIV-1 transmission.

Functional and morphological development of lymphoid tissues and immune regulatory and effector function in rhesus monkeys: cytokine-secreting cells, immunoglobulin-secreting cells, and CD5(+) B-1 cells appear early in fetal development.

Little is known regarding the timing of immune ontogeny and effector function in fetal humans and nonhuman primates. We studied the organization of lymphocyte and antigen-presenting cell populations in developing lymphoid tissues of rhesus monkey fetuses during the second and third trimesters (65 to 145 days of gestation; term = 165 days). Immunoglobulin-secreting and cytokine-secreting cells were detected at day 80. The thymus, spleen, lymph nodes, and intestinal mucosa were examined for cells expressing CD3, CD5, CD20, CD68, p55, and HLA-DR. In the spleens of 65-day-old fetuses (early second trimester), the overwhelming majority of total lymphocytes were CD5(+) CD20(+) B-1 cells. The remaining lymphocytes were CD3(+) T cells. By day 80, splenic B and T cells were equal in number. Intraepithelial CD3(+) CD5(-) T cells and lamina propria CD20(+) CD5(+) B cells were present in the intestines of 65-day-old fetuses. By day 80, numerous CD20(+) CD5(+) B cells were present in the jejunums and colons and early lymphocyte aggregate formation was evident. The spleens of 80- to 145-day-old fetuses contained immunoglobulin M (IgM)-secreting cells, while IgA-, IgG-, interleukin-6-, and gamma interferon-secreting cells were numerous in the spleens and colons. Thus, by the second trimester, the lymphoid tissues of the rhesus monkey fetus have a complete repertoire of properly organized antigen-presenting cells, T cells, and B cells.