Immune therapy for human papillomaviruses-related cancers

Human papillomaviruses(HPVs) are a large family of double strand DNA viruses comprising more than 180 types. Infection with HPV is very common and it is associated with benign and malignant proliferation of skin and squamous mucosae. Many HPVs, considered lowrisk such as HPV 6 and 11, produce warts; while highrisk viruses, such as HPVs 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, and 58, induce tumors. About 5% of all cancers in men and women are associated with HPV infection. Because there are not antiviral drugs for HPV infection, current therapies for low-risk HPV infections involve physical removal of the lesion by cryotherapy, trichloracetic acid, laser, or surgical removal. Surgical procedures are effective in the treatment of precancerous lesions, however after these procedures, many recurrences appear due to new re-infections, or to failure of the procedure to eliminate the HPV. In addition, HPV can inhibit recognition of malignant cellsby the immune system, leading to the development of cancer lesions. When this occurs, radiotherapy and chemotherapy are then used. Unfortunately, about 50% of the HPV-cancer patients still die. In the past decade, a better knowledge of the natural history of the virushost interaction and of the immune response against this viral infection has brought new therapeutic strategies geared to modulate the immune system to generate an efficient virus-specific cytotoxic response. Novel HPV protein-expressing vaccines have shown some significant clinical efficacy and systemic HPV-specific cytotoxic T cell responses. This review will describe the current status of the several therapeutic strategies used to treat HPV-induced lesions, and discuss the various new therapies now being tested.

Fatty liver disease,an emerging etiology of hepatocellular carcinoma in Argentina

AIM To investigate any changing trends in the etiologies of hepatocellular carcinoma(HCC) in Argentina during the last years. METHODS A longitudinal cohort study was conducted by 14 regional hospitals starting in 2009 through 2016. All adult patients with newly diagnosed HCC either with pathology or imaging criteria were included. Patients were classified as presenting non-alcoholic fatty liver disease(NAFLD) either by histology or clinically, provided that all other etiologies of liver disease were ruled out, fatty liver was present on abdominal ultrasound and alcohol consumption was excluded. Complete follow-up was assessed in all included subjects since the date of HCC diagnosis until death or last medical visit.RESULTS A total of 708 consecutive adults with HCC were included. Six out of 14 hospitals were liver transplant centers(n = 484). The prevalence of diabetes mellitus was 27.7%. Overall, HCV was the main cause of liver disease related with HCC(37%) including cirrhotic and non-cirrhotic patients, followed by alcoholic liver disease 20.8%, NAFLD 11.4%, cryptogenic 9.6%, HBV 5.4% infection, cholestatic disease and autoimmune hepatitis 2.2%, and other causes 9.9%. A 6-fold increase in the percentage corresponding to NAFLDHCC was detected when the starting year, i.e., 2009 was compared to the last one, i.e., 2015(4.3% vs 25.6%; P < 0.0001). Accordingly, a higher prevalence of diabetes mellitus was present in NAFLD-HCC group 61.7% when compared to other than NAFLD-HCC 23.3%(P < 0.0001). Lower median AFP values at HCC diagnosis were observed between NAFLD-HCC and non-NAFLD groups(6.6 ng/m L vs 26 ng/m L; P = 0.02). Neither NAFLD nor other HCC etiologies were associated with higher mortality.CONCLUSION The growing incidence of NAFLD-HCC documented in the United States and Europe is also observed in Argentina, a confirmation with important Public Health implications.

Fc receptors: Cell activators of antibody functions

At the onset of an infection early defense systems, such as complement, get into action. Specialized leukocytes (white blood cells) of the innate immune system, including monocytes, macrophages, and neutrophils also participate as a first line of defense against infections. These early responses are rapid but not very specific and are usually not enough to clear completely many infections. The adaptive immune system is also needed to finish the job against many microorganisms. Antibody molecules, produced during the adaptive immune response, are crucial for preventing recurrent infections. Although, IgG antibodies are essential for controlling infections, these molecules do not directly damage the microorganisms they recognize. Today, it is established that leukocytes of the innate immune system are responsible for the protective effects of these antibodies. IgG molecules bind to their cognate antigens and are in turn recognized by specific receptors (Fcγ receptors) on the membrane of leukocytes. Crosslinking these receptors on the surface of leukocytes leads to activation of several effector cell functions. These effector functions are geared toward the destruction of microbial pathogens and the induction of an inflammatory state that is beneficial during infections. However, in autoimmune diseases, antibodies can direct these effector functions against normal tissues and cause severe tissue damage. In recent years, several factors that can modulate the IgG-FcγR interaction have been elucidated. In this review, we describe the main types of Fcγ receptors, and our current view of how antibody variants interact with these receptors to initiate different cell responses. In addition, new findings on the signaling role of individual Fcγ receptors are also discussed.