Effects of Combined Application of NRTUAs and ABP on Growth and Humoral Immunity of Chicks

[Objectives]The paper was to study the effects of combined application of nonreplicating Toxoplasma uracil auxotrophs(NRTUAs)and Agaricus blazei Murill polysaccharide(ABP)on growth and humoral immunity of chicks.[Methods]A total of 120 one-day old female Hyline brown laying hens were randomly divided into 4 groups,30 hens for each group.The chicks in group 1 were subcutaneously injected with NRTUAs and fed on the diet containing with ABP;the chicks in group 2 were subcutaneously injected with NRTUAs;the chicks in group 3 were subcutaneously injected with equal volume of PBS,and fed on the diet containing with ABP;the chicks in group 4 were subcutaneously injected with equal volume of PBS.The body weight of chicks in each group was counted at the 21^(st),42^(nd),84^(th)and 112^(th)week.During this period,blood samples were collected from chicks in each group at 0,7,14,21,28 and 35 d post immunization against Newcastle disease(ND),and serum was separated to detect the antibody titer of ND.[Results]The combined application of NRTUAs and ABP had no effect on growth of chicks,but promoted the humoral immune response of chicks,significantly improved the ND antibody level of chicks,and could maintain high levels of antibodies in the body for a long time.[Conclusions]The study lays a theoretical foundation for further developing the clinical application of NRTUAs and ABP.

STUDIES ON LYMPHOCYTE SUBSETS, HUMORAL IMMUNITY AND THEIR RELATIONSHIP WITH SELENIUM IN PATIENTS WITH KASHIN-BECK DISEASE

Objective To study the humoral immunity status and distribution pattern of lymphocyte subgroups of peripheral blood mononuclear cell (PBMC) in patients with Kashin-Beck Disease (KBD), and their relationship with erythrocyte selenium. Methods 23 X-ray diagnosed patients, 22 age- and sex- matched healthy children in KBD affected area (KAA), and 25 in KBD non-affected area (KNAA) were randomly selected. Immunohistochemistry with monoclonal antibodies anti-CD4, anti-CD8, anti-CD20 was conducted to analyze the lymphocyte subsets. Serum IgM, IgA, IgG, Complement C3 and C4 were assayed using rate nephelometry (Array 360 System, USA). The contents of erythrocyte selenium was determined by 2,3-diaminonaphthalene fluorescence assay. Results CD4+ and CD8+ cells percentage in PBMCs and serum IgA were significantly lower in KAA than those in KNAA(P< 0.05). CD20+ percentage in KAA displayed a decreasing trend compared to KNAA, although not statistically significantly. No statistical differences were found in CD4/CD8 ratio, serum IgG, IgM, C3 and C4 levels. Erythrocyte selenium level in KAA still showed a pronounced decrease compared to that in KNAA. Correlation analysis showed that erythrocyte selenium contents had a strong association with the CD4 cell percentage (r= 0.625, P< 0.05), as well as serum IgA (r= 0.462, P< 0.05). In addition, a moderate correlation between the serum IgA and CD4+ percentage (r= 0.130, P> 0.05) was found. Conclusion These results suggested that children in KAA had a comparably low cellular immunity level and their humoral immunity status was also in a state of moderate immune suppression. Of this immune disorder in Kashin-Beck disease patients, selenium deficiency probably played a critical role via affecting the distribution pattern of peripheral blood lymphocyte. Selenium-deficiency and immune impairment maybe both have something to do with the cause-effect chain of KBD.

Impact of exercise on markers of B cell-related immunity:A systematic review

Background:B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins.Exercise alters B cell counts and immunoglobulin levels,but evidence-based conclusions on potential benefits for adaptive immunity are lacking.This systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells,immunoglobulins,and markers of secretory immunity in human biofluids.Methods:According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,MEDLINE,Web of Science,and Embase were searched on March 8,2023.Non-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions,immunoglobulin levels,salivary flow rate,or secretory immunoglobulin A secretion rate were included.Quality and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in Exercise.Study characteristics,outcome measures,and statistically significant changes were summarized tabularly.Results:Of the 67 eligible studies,22 applied acute exercise and 45 applied exercise training.All included outcomes revealed significant alterations over time in acute exercise and exercise training context,but only a few investigations showed significant differences compared to control conditions.Secretory and plasma immunoglobulin A levels were most consistently increased in response to exercise training.Conclusion:B cell-related outcomes are altered by acute exercise and exercise training,but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise modalities.Well-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.

Effects of soybean raffinose on growth performance,digestibility,humoral immunity and intestinal morphology of growing pigs

There are appreciable does of raffinose in soybean,but the impacts of raffinose on pigs are poorly investigated.We used 2 experiments to investigate the influence of soybean raffinose on growth per-formance,digestibility,humoral immunity and intestinal morphology of growing pigs.In Exp.1,a total of 30 crossbred(Duroc×Landrace×Yorkshire)barrows(21.93±0.43 kg)were randomly divided into 3 groups,and were fed with the control diet,the control diets supplemented with 0.2%and 0.5%raffinose,respectively,for 21 d.Results showed that the addition of 0.2%or 0.5%raffinose reduced(P<0.05)average daily feed intake(ADFI),average daily gain(ADG)and nutrient digestibility,and dietary 0.5%raffinose increased the ratio of feed to gain(P<0.05).For serum indexes,dietary 0.5%raffinose decreased growth hormone and increased glucagon-like peptide-2,immunoglobulin G,tumor necrosis factor-α(TNF-α)and interleukin-6 concentration(P<0.05).In Exp.2,a total of 24 crossbred barrows(38.41±0.45 kg)were randomly divided into 3 groups,and were fed with the control diet(ad libitum),the raffinose diet(0.5%raffinose,ad libitum),and the control diet in the same amount as the raffinose group(feed-pair group)for 14 d,respectively.Compared with the control diet,dietary 0.5%raffinose decreased ADFI(P<0.05).Intriguingly,the raffinose group had lower ADG than the feed-pair group,lower nutrient digestibility,lower amylase activity in duodenum,lower amylase,lipase and trypsin ac-tivities in jejunum and higher TNF-αconcentration in serum compared with the other 2 groups,and a higher ratio of villus height to crypt depth compared with the control group(P<0.05).These results showed that soybean raffinose could reduce feed voluntary intake and body gain while improving in-testinal morphology without a significant negative influence on immunity.Taken together,dietary raffinose could decrease growth performance by reducing both feed intake and nutrient digestibility while inducing humoral immune response of growing pigs.

Characterization of SARS-CoV-2-specific humoral immunity and its potential applications and therapeutic prospects

Coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is an ongoing pandemic that poses a great threat to human health worldwide.As the humoral immune response plays essential roles in disease occurrence and development,understanding the dynamics and characteristics of virus-specific humoral immunity in SARS-CoV-2-infected patients is of great importance for controlling this disease.In this review,we summarize the characteristics of the humoral immune response after SARS-CoV-2 infection and further emphasize the potential applications and therapeutic prospects of SARSCoV-2-specific humoral immunity and the critical role of this immunity in vaccine development.Notably,serological antibody testing based on the humoral immune response can guide public health measures and control strategies;however,it is not recommended for population surveys in areas with very low prevalence.Existing evidence suggests that asymptomatic individuals have a weaker immune response to SARS-CoV-2 infection,whereas SARS-CoV-2-infected children have a more effective humoral immune response than adults.The correlations between antibody(especially neutralizing antibody)titers and protection against SARS-CoV-2 reinfection should be further examined.In addition,the emergence of cross-reactions among different coronavirus antigens in the development of screening technology and the risk of antibody-dependent enhancement related to SARS-CoV-2 vaccination should be given further attention.

Impairment of cellular and humoral immunity in overweight Mongolian gerbils (Meriones unguiculatus)

Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is suppressed in overweight Mongolian gerbils(Meriones unguiculatus).In the study,16 overweight(body mass:90.8-127.6 g)and 16 lean gerbils(body mass:60.5-77.7 g)were randomly selected from a total of 174 male gerbils(body mass range:55.8-144.7 g).Half of the overweight and lean males were injected with sterile saline;the others were immunochallenged(IC)with phytohaemagglutinin and keyhole limpet hemocyanin to assess cellular and humoral immunity,respectively.Body fat mass,wet and dry spleen mass,leukocyte counts,blood glucose levels and serum leptin levels were significantly higher in the overweight gerbils than in the lean gerbils.However,phytohemagglutinin response indicative of cellular immunity and immunoglobulin G concentrations was significantly lower in the IC overweight gerbils than in the IC lean gerbils.These results indicate that cellular and humoral immunity are impaired in the overweight gerbils.Excessive body fat mass,higher leukocyte counts and serum leptin levels imply that overweight gerbils are in a low grade inflammatory state.

COVID-ONE-hi:The One-stop Database for COVID-19-specific Humoral Immunity and Clinical Parameters

Coronavirus disease 2019(COVID-19),which is caused by SARS-CoV-2,varies with regard to symptoms and mortality rates among populations.Humoral immunity plays critical roles in SARS-CoV-2 infection and recovery from COVID-19.However,differences in immune responses and clinical features among COVID-19 patients remain largely unknown.Here,we report a database for COVID-19-specific IgG/IgM immune responses and clinical parameters(named COVID-ONE-hi).COVID-ONE-hi is based on the data that contain the IgG/IgM responses to 24 full-length/truncated proteins corresponding to 20 of 28 known SARS-CoV-2 proteins and 199 spike protein peptides against 2360 serum samples collected from 783 COVID-19 patients.In addition,96 clinical parameters for the 2360 serum samples and basic information for the 783 patients are integrated into the database.Furthermore,COVID-ONE-hi provides a dashboard for defining samples and a one-click analysis pipeline for a single group or paired groups.A set of samples of interest is easily defined by adjusting the scale bars of a variety of parameters.After the“START”button is clicked,one can readily obtain a comprehensive analysis report for further interpretation.COVID-ONE-hi is freely available at www.COVID-ONE.cn.

On the winter enhancement of adaptive humoral immunity: hypothesis testing in desert hamsters (Phodopus roborovskii: Cricetidae, Rodentia) kept under long-day and short-day photoperiod

We tested the winter immunity enhancement hypothesis(WIEH)on male desert hamsters(Phodopus roborovskii)kept under long-day(LD)and short-day(SD)photoperiods.We assumed that under SD in a laboratory,the adaptive humoral immune responsiveness to the antigenic challenge would be enhanced due to the lack of winter physical stressors and food shortages and/or because of the action of an endogenous winter bolstering mechanism,while under LD the immune responsiveness would be suppressed by the activity of the reproductive system.The results support the WIEH in part.We did not find a difference in antibody production in response to sheep erythrocytes between SD and LD hamsters,but SD males had the lower number of granulocytes and the higher number of lymphocytes in white blood cell counts.Reproductive activity was lower in SD males.These males demonstrated an increase in their mass-specific resting metabolic rate,their mass-specific maximal metabolic rate and their level of cortisol.The result of a generalized linear model analysis indicates the negative effect on secondary immunoresponsiveness to sheep erythrocytes of mid-ventral gland size,the organ characterizing individual reproductive quality,and designates a tradeoff between antibody production and reproductive effort.The mass-independent maximal metabolic rate also negatively affected antibody production,indicating a tradeoff between maximal aerobic performance and the adaptive immune function.The higher stress in SD males seems to be the most likely reason for the lack of the effect of daylight duration on antibody production.

Global dynamics in an age-structured HIV model with humoral immunity

In this paper,we formulate an age-structured HIV model,in which the influence of humoral immunity and the infection age of the infected cells are considered.The model is governed by three ordinary differential equations and two first-ordered partial differential equations and admits three equilibria:disease-free,immune-inactivated and immune-activated equilibria.We introduce two important thresholds:the basic reproduction number R〇and immune-activated reproduction number R\and further show the global stability of above three equilibria in terms of R〇and Ri,respectively.The numerical simulations are presented to illustrate our results.

Characterization of Specific Humoral Immunity in Asymptomatic SARS-CoV-2 Infection

The outbreak of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in December 2019 caused a huge blow to both global public health and global economy.At the early stage of the coronavirus disease 2019(COVID-19)epidemic,asymptomatic individuals with SARS-CoV-2 infection were ignored,without appropriate identification and isolation.However,asymptomatic individuals proved to comprise a high proportion of all SARS-CoV-2-infected individuals,which greatly contributed to the rapid and wide spread of this disease.In this review,we summarize the latest advances in epidemiological characteristics,diagnostic assessment methods,factors related to the establishment of SARS-CoV-2 asymptomatic infection,as well as humoral immune features after SARS-CoV-2 infection or vaccination in asymptomatic individuals,which would contribute to effective control of ongoing COVID-19 epidemic.

B lymphocyte-mediated humoral immunity in the pathogenesis of chronic hepatitis B infection

During hepatitis B virus(HBV)infection,the host immune response,including the presence of functional HBV-specific T cells and HBV-specific antibody-producing B cells,ultimately determines the HBV infection outcome:either the virus is cleared,or infection persists.Functional exhaustion of HBV-specific CD8^(+) cytotoxic T cells is the most important immune feature in chronic HBV infection.However,chronic HBV infection also re-writes humoral immunity,whereby B cells are the leading participants.In this review,we highlight HBV-specific B cell responses and propose future directions for research aimed at the generation of more efficient immunotherapeutic strategies.

Effect of Different Oligosaccharides on Immunity and Production Performance of Piglets

[ Objective] To study the effects of different oligosaccharides on immunity and production performance of piglets.[ Method] A total of 75 Yorkshire x Rongchang piglets were assigned into five groups, 15 in each group. Isomalto-oligosaccharide （ IMO）, fructo-oligosaccharide （ FOS）, mannan-oligosacchadde （MOS）, and mixed oligosacchadde were supplemented to basal diet （7.5 g/kg）, respectively. The control group was also set. The experimental period lasted for 53 d. The clinic symptoms and diarrhea were observed. All piglets were weighed once a week. Feed intake was also recorded. Blood was collected via precaval vein for determination of immunology indexes at the age of 30 and 60 d, respectively. [ Result] The IMO and FOS enhanced cellular immunity of 30-day-old piglets significantly （P 〈 0.05）, and the IMO also enhanced their humoral immunity. The MOS enhanced cellular immunity and humoral immunity of 60-day-old piglets significantly （P 〈 0.05）. It also improved production performance largest, and its diarrhea rate was the lowest. [ Conclusion] Different oligosaccharides have various effects on immunity and production performance of oiolets.

THE HUMORAL ANTITUMOR RESPONSES INDUCED BY IL-4 GENE-MODIFIED TUMOR VACCINE

It is well known that IL4 plays important roles in the induction of humoral immunity. In the present study, the humoral antitumor responses induced by IL4 genemodified tumor vaccine were investigated. The mice were vaccinated with the IL4 genemodified B16 melanoma cells. Then the proliferative capacity of the splenic lymphocytes, the levels of the antibodies in the murine serum against wildtype B16 cells and the cytotoxicity of the serum to wildtype melanoma cells were detected. Our data showed that the LPSinduced proliferation of the splenic lymphocytes from the mice vaccinated with the IL4 genemodified tumor vaccine increased more significantly than that from mice vaccinated with wildtype tumor vaccine. The cytotoxicity of the serum to wildtype melanoma cells also increased markedly when detected. It was also observed that the number of pulmonary metastases decreased more obviously when the mice were intravenously injected with the mixture of wildtype B16 cells and the serum from the mice vaccinated with the IL4 genemodified B16 cells. Our data demonstrated that humoral immunity might contribute to the antitumor effect of IL4 gene therapy.

THE HUMORAL AND CELLULAR IMMUNE RESPONSES INDUCED BY HPV18L1-E6/E7 DNA VACCINES IN MICE

Objective To construct eukaryotic expression vector of HPV18 L1-E6, E7 chimeric gene and examine the humoral and cellular immune responses induced by this DNA vaccines in mice. Methods The C-terminal of major capsid protein L1 gene and mutant zinc finger domains of early E6/7 oncogenes in HPV18 were integrated and inserted into eukaryotic expression vector pVAX1 to generate vaccines pVAX1-L1E6Mxx, E7Mxx. CHO cells were transiently transfected with the individual construct. Target protein expressions in the lysate of the transfected cells were measured by ELISA and immunocytochemistry. After BALB/c mice were vaccinated with various recombinant plasmids(pVAX1-L1-E6M3 or pVAX1-L1-E7M3) and immunie adjuvants (pLXHDmB7-2 or LTB) through different administration routes (intramuscular or intranasal) , the great cellular immune responses were produced as revealed by delayed-type hypersensitivity (DTH) and lymphocyte proliferation, and the expression of IL-4 and IFN-γ cells in CD4 + and CD8 + subpopulations. Results The highly efficient expression of pVAX1-L1E6Mxx, E7Mxx vector in host eukaryotic cells were demonstrated both by ELISA and immunocytochemistry. The level of specific serum IgG against HPV in experiment groups mice was much higher than that of control group, and intranuscular immunization group had the highest antibody level. Intramuscular immunization groups were superior to intranasal immunization groups in DTH response, splenocyte proliferation and CD8+ IFN-γ + cells number, but CD4 + IL4 + cell number was higher in intranasal immunization groups. The immunization groups using pLXHDmB7-2 as adjuvant were superior to other groups in immunoresponse. Conclusion These DNA vaccines produce remarkable cellular and humoral immune responses in the mouse and may provide as prophylatic and therapeutic candidates for HPV induced cancer treatment.

Effects of NS Series Composite Lactobacillus Prepa-ration on Performance,Plasma Biochemical Indexes and Immunity of Sows

[Objective] The study was aimed to investigate the effects of NS series composite lactobacillus preparation on production performance and some immune indexes of sows. [Method] The sows were fed on the diets supplemented with the NS series composite lactobacillus prepara- tion, and the changes of production performance, plasma biochemical indexes, levels of IgG, IgA and IgM in serum and colostrum, and T lympho- cyte subpopulations were detected. [ Result] When the NS series composite lactobacillus preparation was supplemented to the sow diet at a propor- tion of 0.2%, the average weaning litter weight at 21 days old was significantly increased. The serum contents of total protein and glucose as well as the serum activities of aspartate aminotransferase （AST）, alkaline phosphatase （ALP） and superoxide dismutase （SOD） were significantly in- creased after 30 d post delivery. Moreover, the levels of IgG, IgA and IgM in serum and colostrum of sows were significantly increased at the time of delivery and after 30 d post delivery. The antibodies in colostrum could be maintained at high levels. The percentage of CD3 ＊ and CD4~ ｜ympho- cyte subpopulations was also increased after supplementation with the NS series composite lactobacillus preparation at a proportion of 0.2%. [ （Con- des＇ion] The NS series composite lactobacillus preparation can improve performance, promote growth and metabolism, and enhance humoral and cellular immunity in sows.

Efficient Humoral and Cellular Immune Responses Induced by a Chimeric Virus-like Particle Displaying the Epitope of EV71 without Adjuvant

Objective To eliminate the side effects of aluminum adjuvant and His-tag,we constructed chimeric VLPs displaying the epitope of EV71（SP70） without His-tagged.Then evaluating whether the VLPs could efficiently evoke not only humoral but also cellular immune responses against EV71 without adjuvant.Methods The fusion protein was constructed by inserting SP70 into the MIR of truncated HBc Ag sequence,expressed in E.Coli,and purified through ion exchange chromatography and density gradient centrifugation.Mice were immunized with the VLPs and sera were collected afterwards.The specific antibody titers,Ig G subtypes and neutralizing efficacy were detected by ELISA,neutralization assay,and EV71 lethal challenge.IFN-γ and IL-4 secreted by splenocytes were tested by ELISPOT assay.Results HBc-SP70 proteins can self-assemble into empty VLPs.After immunization with HBc-SP70 VLPs,the detectable anti-EV71 antibodies were effective in neutralizing EV71 and protected newborn mice from EV71 lethal challenge.There was no significant difference for the immune efficacy whether the aluminum adjuvant was added or not.The specific Ig G subtypes were mainly IgG1 and IgG2 b and splenocytes from the mice immunized produced high levels of IFN-γ and IL-4.Conclusion The fusion proteins without His-tagged was expressed and purified as soluble chimeric HBc-SP70 VLPs without renaturation.In the absence of adjuvant,they were efficient to elicit high levels of Th1/Th2 mixed immune response as well as assisted by aluminum adjuvant.Furthermore,the chimeric VLPs have potential to prevent HBV and EV71 infection simultaneously.

Functional identification of C-type lectin in the diamondback moth,Plutella xylostella(L.)innate immunity

C-type lectins(CTLs)are a superfamily of Ca^(2+)-dependent carbohydrate-recognition proteins,and an important pattern recognition receptor(PRR)in insect innate immunity which can mediate humoral and cellular immunity in insects.In this study,we report a novel dual carbohydrate-recognition domain(CRD)CTL from Plutella xylostella which we designate PxIML.PxIML is a protein with a 969 bp open reading frame(ORF)encoding 322 amino acids,containing a signal peptide and a dual-CRD with EPN(Glu_(124)-Pro_(125)-Asn_(126))and QPD(Gln_(274)-Pro_(275)-Asp_(276))motifs.The expression of PxIML mRNA in the fat body was significantly higher than in hemocytes and midgut.The relative expression levels of PxIML in the whole insect and the fat body were significantly inhibited after infection with Bacillus thuringiensis 8010(Bt8010)at 18 h,while they were significantly upregulated after infection with Serratia marcescens IAE6 or Pichia pastoris.The recombinant PxIML(rPxIML)protein could bind to the tested pathogen-associated molecular patterns(PAMPs),and the bacteria of Enterobacter sp.IAE5,S.marcescens IAE6,Staphylococcus aureus,Escherichia coli BL21,and Bt8010 in a Ca^(2+)-dependent manner,however,it showed limited binding to the fungus,P.pastoris.The rPxIML exhibited strong activity in the presence of Ca^(2+) to agglutinate Bt8010,Enterobacter sp.IAE5 and S.aureus,but it only weakly agglutinated with E.coli BL21,and could not agglutinate with S.marcescens IAE6 or P.pastoris.Furthermore,the rPxIML could bind to hemocytes,promote the adsorption of hemocytes to beads,and enhance the phenoloxidase(PO)activity and melanization of P.xylostella.Our results suggest that PxIML plays an important role in pathogen recognition and in mediating subsequent humoral and cellular immunity of P.xylostella.

Pre-evaluation of humoral immune response of Bactrian camels by the quantification of Th2 cytokines using real-time PCR

With the increasing immunological studies on camels due to the advantage of their single-chain antibodies for humanizations,it is demanding to develop an easy-to-handle evaluation method of their humoral immune response before proceeding with immunization of foreign antigens that may be toxic to camels.In this study,we quantitatively determined the expression levels of T-helper 2(Th2) cytokines in peripheral blood lymphocytes obtained from Bactrian camels by real-time PCR.The recorded kinetic profiles resulting from the immunization of ovalbumin(OVA) indicated that after immunization,Th2 cytokines including interleukin(IL) families such as IL-4,IL-10,and IL-13 in the camels were up-regulated by a factor of 1.78,3.15,and 1.22,respectively,which was validated by traditional enzyme-linked immunosorbent assay(ELISA) methods.Unlike ELISA which requires specific enzyme-labeled antibodies,this established method based on the minimal amount of blood samples holds an advantage in the preliminary evaluation of camel humoral immune response with desirable precision,which is meaningful for biomedical explorations of camel-derived antibodies.

Enhancement of Humoral Immune Response of Newcastle Disease Vaccine by ATRA

[ Objective] The paper was to study the immune enhancement of ATRA on Newcastle Disease （ND） vaccine. [ Method ] The 1-day-old AA broilers were treated with ATRA at the doses of I and 5 p.mol/kg, respectively. At 7 and 28 days of age, broilers in drug control group, low dose group and high dose group were immunized with ND vaccine by intranasal and eye immunization approach. At 7, 14, 21, 28, 35, 42 and 49 clays of age, seven chickens were randomly se- lected from each group and weighed. The thymus, spleen, bursa of fabrieius and serum were collected for calculating immune organ index of thymus, spleen and bursa of fabricius. The ND specific antibody titers in serum were determined with HI test. [Result] ATRA promoted the growth of thymus, spleen and bursa of fabricius, and improved the immune organ index and ND specific antibody titers of chicks. [ Conclusion] ATRA enhanced the humoral immune response of chicks, and ATRT at the dose of 5 μmol/kg presented more prominent immune enhancement effect on ND vaccine.

Humoral and cellular immunity against diverse SARS-CoV-2 variants

Since the outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019, the virus has rapidly spread worldwide. This has led to an unprecedented global pandemic, marked by millions of COVID-19 cases and a significant number of fatalities. Over a relatively short period, several different vaccine platforms are developed and deployed for use globally to curb the pandemic. However, the genome of SARS-CoV-2 continuously undergoes mutation and/or recombination, resulting in the emergence of several variants of concern (VOC). These VOCs can elevate viral transmission and evade the neutralizing antibodies induced by vaccines, leading to reinfections. Understanding the impact of the SARS-CoV-2 genomic mutation on viral pathogenesis and immune escape is crucial for assessing the threat of new variants to public health. This review focuses on the emergence and pathogenesis of VOC, with particular emphasis on their evasion of neutralizing antibodies. Furthermore, the memory B cell, CD4+, and CD8+ T cell memory induced by different COVID-19 vaccines or infections are discussed, along with how these cells recognize VOC. This review summarizes the current knowledge on adaptive immunology regarding SARS-CoV-2 infection and vaccines. Such knowledge may also be applied to vaccine design for other pathogens.