A Comparative Study on the Nonspecific Immunity of Juvenile Litopenaeus vannamei ever Inhabiting Freshwater and Seawater

A study on the nonspecific immunity of Litopenaeus vannamei ever inhabiting freshwater and seawater was carried out at different molt stages by comparing their total hemocyte count(THC) and respiratory burst(RB) and activity of phenol oxidase(PO), nitric oxide synthase(NOS) and lysozyme(LY). Two-way ANOVA showed that salinity and molt stage independently affected THC and RB and the activity of PO, NOS and LY of juvenile L. vannamei significantly(P < 0.05). The THC and RB and the activity of NOS gradually increased from the post-molt stages(A and B) to the pre-molt stages(D0–D3), which were common in shrimps inhabiting freshwater and seawater. The activity of PO peaked at the inter-molt stage(C), and touched the lowest at the post-molt stage in freshwater and pre-molt stage in seawater. The activity of LY was stable over the molt cycle. The RB and the activity of PO, NOS and LY of juvenile L. vannamei were significantly lower in freshwater than in seawater; whereas THC was significantly higher in freshwater than in seawater(P < 0.05). It was concluded that the post-molt stage(especially stage A) was critical to shrimp culture, which should be intensively attended when L. vannamei was cultured in freshwater.

Growth performance,digestive enzyme activities and serum nonspecific immunity of the red tilapia(Oreochromis mossambicus×Oreochromis niloticus)feddiets supplemented with ultrafine powder of Enteromopha prolifera

The present study evaluated ef fects of ultrafine powder of the green macroalgae E nteromopha prolifera as dietary supplement on growth performance, digestive enzyme activities and serum nonspecific immune responses of the red tilapia(O reochromis mossambicus × Oreochromis niloticus). The red tilapia were fed five diets supplemented with different levels of E. prolifera ultrafine powder as well as a control diet containing no E. prolifera for seven weeks(Diets 0–6 contained 0(control), 10, 20, 30, 40 and 50 g/kg of E. prolifera ultrafine powder, respectively). The results showed that diets supplemented with E. prolifera ultrafine powder generally improved growth, immunity and digestive enzyme activities of the red tilapia. In particular, the fish fed the diet incorporated 50 g/kg (5%) E. prolifera ultrafine powder(Diet 5) achieved the highest percentage weight gain, specific growth rate and the condition factor(increased by 15.4%, 8.0% and 5.7%, respectively when compared to the control). Feeding the diet also led to significantly increases( P <0.05) in serum nonspecific immune responses, including total superoxide dismutase, acid phosphatase, alkaline phosphatase, lysozyme activities and serum total protein(increased by 19.4%, 48.1%, 29.5%, 30.3% and 8.7%, respectively) as well as digestive enzyme activities of erepsin, gastric amylase, gastric lipase, pepsin, intestinal amylase and gastric lipase(increased by 15.7%, 33.3%, 16.3%, 21.3%, 52.3% and 28.2%, respectively) than those of the control. Based on these results, it is recommended that the inclusion level of E. prolifera ultrafine powder in the diet of the red tilapia should be 50 g/kg(or 5%).

Role of autoimmunity in primary biliary cirrhosis

Primary biliary cirrhosis(PBC) is an autoimmune liver disease characterized by the presence of serum autoantibodies and chronic nonsuppurative destructive cholangitis.The pathogenesis of PBC involves environmental factors,genetic predisposition and loss of immune tolerance.In recent years,it has become univocally accepted that an inappropriately activated immune response is one of the most important factors in PBC.In this study,the role of autoimmunity in PBC is summarized and a feasible research orientation is recommended.

SARS-COV-2 Infection and Anti-Tuberculosis Immunity: Temporal Association or Real Protective Role?

Introduction: According to the literature consulted to date, there is epidemiological heterogeneity of Covid-19 between countries depending on their vaccination policy, in particular BCG vaccination. These findings have led to several hypotheses, including the protective role of immunity induced by the BCG tuberculosis vaccine against Covid-19 infection. The immunity induced by the BCG vaccine significantly increases the secretion of pro-inflammatory cytokines, in particular IL-1B, which has been shown to play an essential role in antiviral immunity. This cross-immunity, although not specific, if highlighted, is a real providence that must be taken advantage of in the face of this pandemic. The main objective of this study is to rule out or confirm that anti-tuberculosis immunity protects against SARS-COV-2 in our context. Material and Methods: Two groups will be compared: cases infected with the virus and controls who have never been infected with the virus. Both case and control groups will undergo a tuberculin skin test: the intra dermal tuberculin reaction (IDR). Results: We found that our control group had a high IDR immunity value, with an IDR tuberculin positive percentage of 67.2%. This suggests that immunity to IDR is a protective factor against coronavirus disease. Conclusion: The hypothesis of nonspecific anti-tuberculosis protection deserves further verification studies;it would have large positive repercussions for developing countries.

Physiological and histological responses of Phascolosoma esculenta (Sipuncula: Phascolosomatidea) to acute heat stress

Temperature is an important factor affecting the growth,development,and survival of organisms.The effects of temperature stress on aquatic organisms have received increasing attention,as these organisms are mostly poikilotherms and their body temperature are directly corresponding changes with ambient temperature,resulting in they are easily exposed in temperature stress.However,little is known about the effects of high temperature on Sipuncula.In this study,we investigated the effects of acute heat stress on malondialdehyde(MDA)concentration,the activities of antioxidant(superoxide dismutase and glutathione peroxidase)and immunity-related(acidic and alkaline phosphatase)enzymes,heat shock protein 70(hsp70)and hsp90 gene expression,and the histological structure of the sipunculid Phascolosoma esculenta.Within the coelom fl uid,the MDA concentration and all detected antioxidant enzyme activities increased during high temperature stress;signifi cant increases were also observed here and in the intestine in the hsp70 and hsp90 mRNA expression levels.These results indicated that acute heat stress caused oxidative stress;antioxidants and heat shock proteins probably act to protect P.esculenta against oxidative damage,constituting part of its physiological mechanism for adaptation to high temperatures.In addition,the increased activity of the acidic and alkaline phosphatases indicated eff ects on its nonspecifi c immune system.Furthermore,damaged tissue structures were observed in the body wall,retractor muscle,intestine,and nephridium after 96 h of 40-℃ stress.The damaged cells of these tissues showed obvious condensed chromatin around the nuclear membrane.This histological damage suggests that heat stress could affect movement,food absorption,digestion,and excretion in P.esculenta.These results elucidate the effects of temperature stress on P.esculenta and its physiological response mechanisms and provide practical indicators for assessing heat stress status and determining suitable culture temperatures for P.esculenta.

Mechanistic insight into the gut microbiome and its interaction with host immunity and inflammation

The intestinal tract is a host to 100 trillion of microbes that have co-evolved with mammals over the millennia.These commensal organisms are critical to the host survival.The roles that symbiotic microorganisms play in the digestion,absorption,and metabolism of nutrients have been clearly demonstrated.Additionally,commensals are indispensable in regulating host immunity.This is evidenced by the poorly developed gut immune system of germ-free mice,which can be corrected by transplantation of specific commensal bacteria.Recent advances in our understanding of the mechanism of host emicrobial interaction have provided the basis for this interaction.This paper reviews some of these key studies,with a specific focus on the effect of the microbiome on the immune organ development,nonspecific immunity,specific immunity,and inflammation.

Antitumor immune responses induced by photodynamic and sonodynamic therapy:a narrative review

The immune system has the function of immune surveillance to resist the occurrence and development of tumors,and is essential for inhibition of tumor metastasis.Nevertheless,tumor cells can still suppress immune responses through multiple mechanisms to escape recognition and elimination.Photodynamic and sonodynamic therapy involve systemic or local use of sensitizers followed by light or ultrasound treatment of the affected area,leading to tumor cell death by various mechanisms.The capability of the immune system is essentially affected by photodynamic and sonodynamic therapy.To understand the tumor therapeutic mechanisms of photodynamic and sonodynamic therapy and to explore the use of these modalities for improvement of the antitumor immune effect,extensive preclinical and clinical studies have been carried out.Besides direct killing of tumors,photodynamic and sonodynamic therapy also cause inflammatory reactions,achieve antitumor immune responses,and potentially prevent tumor recurrence,thereby treating both primary and metastatic tumors.In this review,we summarize the antitumor immune responses induced by photodynamic and sonodynamic therapy,describe the processes of the antitumor immune responses in detail,and discuss the clinical applications of the resulting antitumor immunity.