Immunological correlates of protection mediated by a whole organism Cryptococcus neoformans vaccine deficient in chitosan.

The global burden of infections due to the pathogenic fungus Cryptococcus is substantial in persons with low CD4 + T cell counts. Previously, we deleted three chitin deacetylase genes from C. neoformans to create a chitosan-deficient, avirulent strain, designated cda1Δ2Δ3Δ which, when used as a vaccine, protected mice from challenge with virulent C. neoformans strain KN99. Here, we explored the immunological basis for protection. Vaccine-mediated protection was maintained in mice lacking B cells or CD8 + T cells. In contrast, protection was lost in mice lacking α/ß T cells or CD4 + T cells. Moreover, CD4 + T cells from vaccinated mice conferred protection upon adoptive transfer to naive mice. Importantly, while monoclonal antibody-mediated depletion of CD4 + T cells just prior to vaccination resulted in complete loss of protection, significant protection was retained in mice depleted of CD4 + T cells after vaccination, but prior to challenge. Vaccine-mediated protection was lost in mice genetically deficient in IFNγ, TNFα, or IL-23p19. A robust influx of leukocytes and IFNγ- and TNFα-expressing CD4 + T cells was seen in the lungs of vaccinated and challenged mice. Finally, a higher level of IFNγ production by lung cells stimulated ex vivo correlated with lower fungal burden in the lungs. Thus, while B cells and CD8 + T cells are dispensable, IFNγ and CD4 + T cells have overlapping roles in generating protective immunity prior to cda1Δ2Δ3Δ vaccination. However, once vaccinated, protection becomes less dependent on CD4 + T cells, suggesting a strategy for vaccinating HIV + persons prior to loss of CD4 + T cells. Importance: The fungus Cryptococcus neoformans is responsible for >100,000 deaths annually, mostly in persons with impaired CD4 + T cell function such as AIDS. There are no approved human vaccines. We previously created a genetically engineered avirulent strain of C. neoformans , designated cda1Δ2Δ3Δ . When used as a vaccine, cda1Δ2Δ3Δ protects mice against a subsequent challenge with a virulent C. neoformans strain. Here, we defined components of the immune system responsible for vaccine-mediated protection. We found that while B cells and CD8 + T cells were dispensible, protection was lost in mice genetically deficient in CD4 + T cells, and the cytokines IFNγ, TNFα, or IL-23. A robust influx of cytokine-producing CD4 + T cells was seen in the lungs of vaccinated mice following infection. Importantly, protection was retained in mice depleted of CD4 + T cells following vaccination, suggesting a strategy to protect persons who are at risk for future CD4 + T cell dysfunction.

Protection against experimental cryptococcosis elicited by Cationic Adjuvant Formulation 01-adjuvanted subunit vaccines.

The fungal infection, cryptococcosis, is responsible for >100,000 deaths annually. No licensed vaccines are available. We explored the efficacy and immune responses of subunit cryptococcal vaccines adjuvanted with Cationic Adjuvant Formulation 01 (CAF01). CAF01 promotes humoral and T helper (Th) 1 and Th17 immune responses and has been safely used in human vaccine trials. Four subcutaneous vaccines, each containing single recombinant Cryptococcus neoformans protein antigens, partially protected mice from experimental cryptococcosis. Protection increased, up to 100%, in mice that received bivalent and quadrivalent vaccine formulations. Vaccinated mice that received a pulmonary challenge with C. neoformans had an influx of leukocytes into the lung including robust numbers of polyfunctional CD4+ T cells which produced Interferon gamma (IFNγ), tumor necrosis factor alpha (TNFα), and interleukin (IL)-17 upon ex vivo antigenic stimulation. Cytokine-producing lung CD8+ T cells were also found, albeit in lesser numbers. A significant, durable IFNγ response was observed in the lungs, spleen, and blood. Moreover, IFNγ secretion following ex vivo stimulation directly correlated with fungal clearance in the lungs. Thus, we have developed multivalent cryptococcal vaccines which protect mice from experimental cryptococcosis using an adjuvant which has been safely tested in humans. These preclinical studies suggest a path towards human cryptococcal vaccine trials.

Immune evasion by Cryptococcus gattii in vaccinated mice coinfected with C. neoformans.

Cryptococcus neoformans and C. gattii, the etiologic agents of cryptococcosis, cause over 100,000 deaths worldwide every year, yet no cryptococcal vaccine has progressed to clinical trials. In preclinical studies, mice vaccinated with an attenuated strain of C. neoformans deleted of three cryptococcal chitin deacetylases (Cn-cda1Δ2Δ3Δ) were protected against a lethal challenge with C. neoformans strain KN99. While Cn-cda1Δ2Δ3Δ extended the survival of mice infected with C. gattii strain R265 compared to unvaccinated groups, we were unable to demonstrate fungal clearance as robust as that seen following KN99 challenge. In stark contrast to vaccinated mice challenged with KN99, we also found that R265-challenged mice failed to induce the production of protection-associated cytokines and chemokines in the lungs. To investigate deficiencies in the vaccine response to R265 infection, we developed a KN99-R265 coinfection model. In unvaccinated mice, the strains behaved in a manner which mirrored single infections, wherein only KN99 disseminated to the brain and spleen. We expanded the coinfection model to Cn-cda1Δ2Δ3Δ-vaccinated mice. Fungal burden, cytokine production, and immune cell infiltration in the lungs of vaccinated, coinfected mice were indicative of immune evasion by C. gattii R265 as the presence of R265 neither compromised the immunophenotype established in response to KN99 nor inhibited clearance of KN99. Collectively, these data indicate that R265 does not dampen a protective vaccine response, but rather suggest that R265 remains largely undetected by the immune system.

Improvement in Patient Performance of Skin Self-examinations After Intervention With Interactive Education and Telecommunication Reminders: A Randomized Controlled Study.

OBJECTIVE To determine if interactive computerized patient education, skin self-examination (SSE) tutorials, and telecommunication reminders could be combined to increase patient performance of SSEs, increase confidence in ability to identify melanoma, and influence individual melanoma risk perception. DESIGN A total of 132 adult participants from our dermatology clinics were enrolled in an interventional study and randomized to a control group or an intervention group. Survey data were collected from all participants on the day of enrollment and 3 months after enrollment. SETTING University Hospitals Case Medical Center outpatient dermatology clinics. PARTICIPANTS English speakers older than 18 years. INTERVENTIONS The intervention group (1) participated in a computer-assisted learning tutorial, (2) took part in a hands-on SSE tutorial, (3) received monthly telecommunication reminders to perform SSEs for 12 weeks, and (4) received a brochure on melanoma detection. The control group received only the brochure on melanoma detection. MAIN OUTCOME MEASURES Self-report of performance of SSEs. Melanoma risk perception and confidence in ability to identify melanoma were secondary considerations. Logistic regressions, controlling for race, age, sex, education, and family history of melanoma, were used to assess the effectiveness of the intervention. RESULTS At the 3-month follow-up, those in the intervention group were more likely to perform SSEs (odds ratio [OR], 2.36; P ≤ .05). In addition, those who participated in the intervention were more likely to report being confident in their ability to identify melanoma during an SSE (OR, 2.72; P ≤ .05). CONCLUSION Computer-assisted patient education used in conjunction with a hands-on SSE tutorial and telecommunication reminders can increase patient performance of SSEs and confidence in the ability to identify melanoma.

Physical and mental impact of psoriasis severity as measured by the compact Short Form-12 Health Survey (SF-12) quality of life tool.

The Short Form-12 Health Survey (SF-12) is used to assess the patient's quality of life (QoL) using the physical component score (PCS) and the mental component score (MCS). The purpose of this study was to determine whether the SF-12 PCS and MCS are associated with psoriasis severity and to compare QoL between Murdough Family Center for Psoriasis (MFCP) patients and patients with other major chronic diseases included in the National Survey of Functional Health Status data. We used data from 429 adult patients enrolled in MFCP. Psoriasis Area Severity Index (PASI) was used to assess psoriasis severity at the time of completion of the SF-12 questionnaire. Other variables included age, sex, body mass index, psoriatic arthritis, psychiatric disorders, and comorbidities. Linear regression models were used to estimate effect sizes ± 95% confidence intervals. For every 10-point increase in PASI, there was a 1.1 ± 1.3 unit decrease in MCS (P=0.100) and a 2.4 ± 1.3 unit decrease in PCS (P<0.001). Psoriasis severity was associated with PCS and MCS after adjusting for variables, although the strength of the relationship was attenuated in some models. Psoriasis severity is associated with decreased QoL. SF-12 may be a useful tool for assessing QoL among psoriasis patients.