Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases

Clostridioides difficile(C.difficile)is progressively colonizing humans and animals living with humans.During this process,hypervirulent strains and mutated toxin A and B of C.difficile(TcdA and TcdB)are originating and developing.While in healthy subjects colonization by C.difficile becomes a risk after the use of antibiotics that alter the microbiome,other categories of people are more susceptible to infection and at risk of relapse,such as those with inflammatory bowel disease(IBD).Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma(CKs).Therefore,in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C.difficile infection and its progression and relapses.TcdB is internalized in the cell via three receptors:chondroitin sulphate proteoglycan 4;poliovirus receptor-like 3;and Wnt receptor frizzled family.Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types,while poliovirus receptor-like 3 induces only necrosis.It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis.Therefore,in subjects with IBD there are the conditions:(1)For greater susceptibility to C.difficile infection,such as the inflammatory state,and abnormalities of the microbiome and of the immune system;(2)for the enhancement of the cytotoxic activity of TcdB+Cks;and(3)for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis.The only therapeutic approach currently possible in IBD patients is monitoring of C.difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins.The future perspective is to generate bacteriophages against C.difficile for targeted therapy.

Human papillomavirus and gastrointestinal cancer: A review

Human papillomavirus(HPV) is one of the most common sexually transmitted infections worldwide. Exposure to HPV is very common,and an estimated 65%-100% of sexually active adults are exposed to HPV in their lifetime. The majority of HPV infections are asymptomatic,but there is a 10% chance that individuals will develop a persistent infection and have an increased risk of developing a carcinoma. The International Agency for Research on Cancer has found that the following cancer sites have a strong causal relationship with HPV: cervix uteri,penis,vulva,vagina,anus and oropharynx,including the base of the tongue and the tonsils. However,studies of the aetiological role of HPV in colorectal and esophageal malignancies have conflicting results. The aim of this review was to organize recent evidence and issues about the association between HPV infection and gastrointestinal tumours with a focus on esophageal,colorectal and anal cancers. The ultimate goal was to highlight possible implications for prognosis and prevention.