Induction of Th1 and Th2 CD4+ T cell responses by oral or parenteral immunization with ISCOMS

We examined the ability of oral or parenteral immunization with immune stimulating complexes containing ovalbumin (ISCOMS-OVA) to prime T cell proliferative and cytokine responses. A single subcutaneous immunization with ISCOMS-OVA primed potent antigen-specific proliferative responses in the draining popliteal lymph node, which were entirely dependent on the presence of CD4⁺ T cells. CD8⁺ T cells did not proliferate in vitro even in the presence of the appropriate peptide epitope and exogenous interleukin (IL)-2. Primed popliteal lymph node cells produced IL-2, IL-5 and interferon (IFN)-γ, but not IL-4 when restimulated with OVA in vitro. Serum antigen-specific IgG1 and IgG2a antibody responses were also primed by subcutaneous immunization with ISCOMS-OVA, confirming the stimulation of both Th1 and Th2 cells in vivo. Spleen cells from subcutaneously primed mice produced a similar pattern of cytokines, indicating that disseminated priming had occurred. Oral immunization with ISCOMS-OVA also primed local antigen-specific proliferative responses in the mesenteric lymph node and primed an identical pattern of systemic cytokine responses in the spleen. The ability of ISCOMS to prime both Th1 and Th2 CD4⁺ T cell responses may be central to their potent adjuvant activities and confirm the potential of ISCOMS as future oral vaccine vectors.     

Effects of the Sunny Days, Healthy Ways curriculum on students in grades 6 to 8

BACKGROUND: There are few effective sun-safety education programs for use in secondary schools. Project aims were to create a sun-safety curriculum for grades 6 to 8, and to test whether exposure to the curriculum would increase children's sun-protection behavior. DESIGN: A pair-matched, group-randomized, pre--post test, controlled trial was performed with middle schools as the unit of randomization. Teachers implemented the six-unit sun-safety curriculum in 2001-2003, and analyses were performed in 2003-2004. SETTING/PARTICIPANTS: A total of 2038 children from 30 middle schools in Colorado, New Mexico, and Arizona. MAIN OUTCOME MEASURES: Self-reported sun-protection behavior using frequency ratings and diary. RESULTS: Compared to control schools, children receiving the curriculum reported more frequent sun protection (p=0.0035), and a greater proportion wore long-sleeved shirts during recess (p<0.0001) and applied sunscreen (p<0.0001). Exposure to the curriculum improved knowledge (p<0.0001), decreased perceived barriers to using sunscreen (p=0.0046), enhanced self-efficacy expectations (p=0.0577) about sun safety, and reduced favorable attitudes toward sun tanning (p=0.0026 to <0.0001). In intent-to-treat analyses, the treatment effect was eliminated only under the most conservative assumptions about dropouts. CONCLUSIONS: Educational approaches to sun safety in middle school may be effective for improving children's sun safety. Potential trial limitations include measuring short-term outcomes, focusing on young adolescents, using active parental consent, and testing in the American Southwest.