Mucosal Immunity

Secretory Abs of the IgA and IgM isotypes are the foot soldiers of the mucosal immune system, serving as the first line of specific immunity against inhaled, ingested, and sexually transmitted Ags. Adult humans transport some 3 g/d of secretory (SIgA) into external secretions, more than the daily

Author summary The molecular basis by which small amounts of HIV can initiate infection in the mucosa is not well understood. Here, we report that genital and rectal fibroblasts, amongst the most abundant cells of the mucosa, potently increase HIV infection of T cells. Fibroblasts are more abundant and can be more effective as infection enhancers than dendritic cells, which are thought to play a role in early HIV transmission by facilitating infection of T cells. In contrast to fibroblasts, mucosal epithelial cells, which line the mucosa, inhibit HIV infection. Our findings suggest that abrasions in the genital and rectal epithelium may increase HIV transmission in part by allowing external HIV to escape an antiviral environment to access the infection-favorable environment of the stromal fibroblasts. These studies suggest that approaches to limit fibroblast-mediated enhancement may diminish HIV transmission rates.

Immune protection against infectious diseases is most effective if located at the portal of entry of the pathogen. Hence, there is an increasing demand for vaccine formulations that can induce strong protective immunity following oral, respiratory, or genital tract administration. At present, only few mucosal vaccines are found on the market, but recent technological advancements and a better understanding of the principles that govern priming of mucosal immune responses have contributed to a more optimistic view on the future of mucosal vaccines. Compared to live attenuated vaccines, subcomponent vaccines, most often protein-based, are considered safer, more stable, and less complicated to manufacture, but they require the addition of nontoxic and clinically safe adjuvants to be effective. In addition, another limiting factor is the large antigen dose that usually is required for mucosal vaccines. Therefore, the combination ofmucosal adjuvantswith the recent progress in nanoparticle technology provides an attractive solution to these problems. In particular, the liposome technology is ideal for combining protein antigen and adjuvant into an effective mucosal vaccine. Here, we describe and discuss recent progress in nanoparticle formulations using various types of liposomes that convey strong promise for the successful development of the next generation of mucosal vaccines.

Researchers discover strong genetic risk factor for IgA nephropathy - https://t.co/oz1OI8REt5

Secretory Abs of the IgA and IgM isotypes are the foot soldiers of the mucosal immune system, serving as the first line of specific immunity against inhaled, ingested, and sexually transmitted Ags. Adult humans transport some 3 g/d of secretory (SIgA) into external secretions, more than the daily

Severe viral lower respiratory infections are a major cause of infant morbidity. In developing countries, respiratory syncytial virus (RSV)-bronchiolitis induces significant mortality, whereas in developed nations the disease represents a major risk factor for subsequent asthma. Susceptibility to severe RSV-bronchiolitis is governed by gene-environmental interactions that affect the host response to RSV infection. Emerging evidence suggests that the excessive inflammatory response and ensuing immunopathology, typically as a consequence of insufficient immunoregulation, leads to long-term changes in immune cells and structural cells that render the host susceptible to subsequent environmental incursions. Thus, the initial host response to RSV may represent a tipping point in the balance between long term respiratory health or chronic disease (e.g. asthma). The composition and diversity of the microbiota, which in humans stabilises in the first year of life, critically affects the development and function of the immune system. Hence, perturbations to the maternal and/or infant microbiota are likely to have a profound impact on the host response to RSV and susceptibility to childhood asthma. Here, we review recent insights describing the effects of the microbiota on immune system homeostasis and respiratory disease, and discuss the environmental factors that promote microbial dysbiosis in infancy. Ultimately, this knowledge will be harnessed for the prevention and treatment of severe viral bronchiolitis as a strategy to prevent the onset and development of asthma.