Landes Highlights

JAK-STAT and intestinal mucosal immunology

The intestinal mucosal immune system is challenged with bacteria, viruses, and parasites, in addition to food and environmental antigens, that require dynamic immune responsiveness for homeostasis. A recent review by Dr Kenneth Kudsk and coworkers highlights the recognized roles of JAK-STAT signaling in the intestinal mucosal immune system in the regulation of both, adaptive and innate mucosal immune function, as well as epithelial repair and regeneration. Adaptive immunity includes lymphocyte mediated secretion of specific antibodies, while innate immune respones include secretion of non-antigen specific compounds. Effects of specialized nutrition support on JAK-STAT in innate immune function and in lymphocyte modulation and epithelial antibody transport in gut-associated lymphoid tissue are discussed (Fig. 1).

Figure 1. Cover of JAK-STAT Volume 2, Issue 4 (October 2013).

Correlate of protection for rotavirus vaccines

Rotavirus (RV) infection is the principle cause of severe gastroenteritis (GE) in young children. Before the introduction of routine immunization, RV was responsible for more than 450 000 deaths annually worldwide. Currently two RV vaccines are available and recommended for infants, but both vaccines are less efficacious in some countries in Africa and Asia. The improvement of available vaccines or the development of new RV vaccines is hindered by the lack of a widely accepted immunological correlate of protection. RV-specific secretory immunoglobulin (RV-SIg) in serum has been proposed as an alternate method for indirectly measuring intestinal Ig. A new study by Juana Angel and colleagues confirmed the presence of plasma RV-SIg in children with natural RV infection, and further adressed its occurrence in children vaccination with the attenuated human RV vaccine Rotarix. They reportet that vaccinees have higher RV-SIg titers than placebo recipients after each of the two administered doses, and that RV-SIg titers increase after the second dose. RV-SIg measured after dose 2 correlated with protection when vaccinees and placebo recipients were analyzed jointly. The study authors propose that plasma RV-SIg may serve as a valuable correlate of protection for RV vaccines (Fig. 2).

Figure 2. Cover of Human Vaccines & Immunotherapeutics Volume 9 Issue 11 (November 2013).

Efficacy of Rotarix in Chinese infants

Rotavirus (RV) infection is a major cause of severe gastroenteritis (GE) in children under 5 years of age. For the first time in China, Dr Rong-cheng Li and colleagues assessed the efficacy of two oral doses of the human RV vaccine Rotarix in infants during the first two years of life. In this study, more than 3.330 healthy infants aged 6–16 weeks were randomized to receive two oral doses of either the vaccine or placebo, given one month apart. Vaccine efficacy (VE) against severe RVGE was assessed from two weeks post-dose 2 up until the end of the second RV season. Unsolicited symptoms reported following vaccination and serious adverse events (SAEs) reported throughout the study were also assessed. The authors found that over two consecutive RV seasons, fewer severe RVGE episodes occurred in the vaccine group (n = 21) compared with the placebo group (n = 75). VE against severe RVGE was 72%. The number of unsolicited symptoms and SAEs reported was similar between both groups. In conclusion the Chinese study showed that two oral doses of Rotarix provides a substantial level of protection against severe RVGE in Chinese children during the first two years of life (Fig. 3).

Figure 3. Cover of Human Vaccines & Immunotherapeutics Volume 10 Issue 1 (January 2014).