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Carica papaya increases regulatory T cells and reduces IFN-γ+ CD4+ T cells in healthy human subjects

Abdullah M, Chai PS, Loh CY, Chong MY, Quay HW, Vidyadaran S, et al.

Mol Nutr Food Res, 2011 May;55(5):803-6.
PMID: 21520494 DOI: 10.1002/mnfr.201100087

Fruit and vegetables have therapeutic potential as they dampen inflammation, have no known side-effects and as whole foods have prospective additive and synergistic benefits. Th1 (IFN-γ(+) CD4(+))/Th2 (IL-4(+)CD4(+)) T cells play a vital role in mediating inflammatory responses and may be regulated by regulatory T cells (Tregs). Effects of Carica papaya on cells of healthy individuals were determined using flow cytometry methods. Significant down-regulation of IFN-γ(+) CD4(+) (p=0.03, n=13), up-regulation of IL-4(+) CD4(+) (p=0.04, n=13) T cells and up-regulation of CD3(+) CD4(+) CD25(+) CD127(-) (p=0.001, n=15) Tregs were observed after papaya consumption. In vitro cultures showed up-regulation of Tregs in male subjects and was significantly associated with levels of IL-1β in culture supernatants (R(2) =0.608, p=0.04, n=12). Other inflammatory cytokines were significantly suppressed. Papaya consumption may exert an anti-inflammatory response mediated through Tregs and have potential in alleviating inflammatory conditions.

Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology
Fulltext Cellular immune responses to recurring influenza strains have limited boosting ability and limited cross-reactivity to other strains

Keynan Y, Card CM, Ball BT, Li Y, Plummer FA, Fowke KR

Clin Microbiol Infect, 2010 Aug;16(8):1179-86.
PMID: 20670292 DOI: 10.1111/j.1469-0691.2010.03142.x

Influenza vaccine provides protection against infection with matched strains, and this protection correlates with serum antibody titres. In addition to antibodies, influenza-specific CD8+ T-lymphocyte responses are important in decreasing disease severity and facilitating viral clearance. Because this response is directed at internal, relatively conserved antigens, it affords some cross-protection within a given subtype of influenza virus. With the possibility of a broader A(H1N1) Mexico outbreak in the fall of 2009, it appeared worthwhile studying the degree of cellular immune response-mediated cross-reactivity among influenza virus isolates. The composition of the 2006-2007 influenza vaccine included the A/New Caledonia/20/1999 strain (comprising a virus that has been circulating, and was included in vaccine preparations, for 6-7 years) and two strains not previously included (Wisconsin and Malaysia). This combination afforded us the opportunity to determine the degree of cross-reactive cellular immunity after exposure to new viral strains. We analysed the antibody responses and the phenotype and function of the T cell response to vaccine components. The results obtained show that antibody responses to A/New-Caledonia were already high and vaccination did not increase antibody or cytotoxic T lymphocyte responses. These data suggest that repeated exposure to the same influenza stain results in limited boosting of humoral and cellular immune responses.

Matched MeSH terms: CD8-Positive T-Lymphocytes/immunology*
Leukaemia and lymphoma in Malaysia

Bosco J, Cherian R, Lin HP, Pang T

Leuk. Res., 1985;9(6):789-91.
PMID: 3874337
Matched MeSH terms: T-Lymphocytes/immunology
Validation of immunogenic PASD1 peptides against HLA-A*24:02 colorectal cancer

Soh JE, Abu N, Sagap I, Mazlan L, Yahaya A, Mustangin M, et al.

Immunotherapy, 2019 10;11(14):1205-1219.
PMID: 31478431 DOI: 10.2217/imt-2019-0073

Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8+ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8+ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.

Matched MeSH terms: CD8-Positive T-Lymphocytes/immunology
Fulltext Human mesenchymal stem cells inhibit the differentiation and effector functions of monocytes

Maqbool M, Algraittee SJR, Boroojerdi MH, Sarmadi VH, John CM, Vidyadaran S, et al.

Innate Immun, 2020 07;26(5):424-434.
PMID: 32635840 DOI: 10.1177/1753425919899132

Although monocytes represent an essential part of the host defence system, their accumulation and prolonged stimulation could be detrimental and may aggravate chronic inflammatory diseases. The present study has explored the less-understood immunomodulatory effects of mesenchymal stem cells on monocyte functions. Isolated purified human monocytes were co-cultured with human umbilical cord-derived mesenchymal stem cells under appropriate culture conditions to assess monocytes' vital functions. Based on the surface marker analysis, mesenchymal stem cells halted monocyte differentiation into dendritic cells and macrophages and reduced their phagocytosis functions, which rendered an inability to stimulate T-cell proliferation. The present study confers that mesenchymal stem cells exerted potent immunosuppressive activity on monocyte functions such as differentiation, phagocytosis and Ag presentation; hence, they promise a potential therapeutic role in down-regulating the unwanted monocyte-mediated immune responses in the context of chronic inflammatory diseases.

Matched MeSH terms: T-Lymphocytes/immunology*
Phytohaemagglutinin-induced lymphocyte transformation in leprosy

Nelson DS, Nelson M, Thurston JM, Waters MF, Pearson JM

Clin Exp Immunol, 1971 Jul;9(1):33-43.
PMID: 5559093
Matched MeSH terms: Lymphocytes/immunology*
Induction of Chronic Subclinical Systemic Inflammation in Sprague-Dawley Rats Stimulated by Intermittent Bolus Injection of Lipopolysaccharide

Ranneh Y, Akim AM, Hamid HA, Khazaai H, Mokhtarrudin N, Fadel A, et al.

Arch Immunol Ther Exp (Warsz), 2019 Dec;67(6):385-400.
PMID: 31278602 DOI: 10.1007/s00005-019-00553-6

Chronic subclinical systemic inflammation has a key role in stimulating several chronic conditions associated with cardiovascular diseases, cancer, rheumatoid arthritis, diabetes, and neurodegenerative diseases. Hence, developing in vivo models of chronic subclinical systemic inflammation are essential to the study of the pathophysiology and to measure the immunomodulatory agents involved. Male Sprague-Dawley rats were subjected to intraperitoneal, intermittent injection with saline, or lipopolysaccharide (LPS) (0.5, 1, 2 mg/kg) thrice a week for 30 days. Hematological, biochemical, and inflammatory mediators were measured at different timepoints and at the end of the study. The hearts, lungs, kidneys, and livers were harvested for histological evaluation. Significant elevation in peripheral blood leukocyte includes neutrophils, monocytes, and lymphocytes, as well as the neutrophils-to-lymphocyte ratio. The pro-inflammatory mediator levels [C-reactive protein, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-8] along with the biochemical profile (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, creatine kinase, creatinine, and urea) were increased significantly (P

Matched MeSH terms: Lymphocytes/immunology*
Fulltext BRF1 accelerates prostate tumourigenesis and perturbs immune infiltration

Loveridge CJ, Slater S, Campbell KJ, Nam NA, Knight J, Ahmad I, et al.

Oncogene, 2020 02;39(8):1797-1806.
PMID: 31740786 DOI: 10.1038/s41388-019-1106-x

BRF1 is a rate-limiting factor for RNA Polymerase III-mediated transcription and is elevated in numerous cancers. Here, we report that elevated levels of BRF1 associate with poor prognosis in human prostate cancer. In vitro studies in human prostate cancer cell lines demonstrated that transient overexpression of BRF1 increased cell proliferation whereas the transient downregulation of BRF1 reduced proliferation and mediated cell cycle arrest. Consistent with our clinical observations, BRF1 overexpression in a Pten-deficient mouse (PtenΔ/Δ BRF1Tg) prostate cancer model accelerated prostate carcinogenesis and shortened survival. In PtenΔ/Δ BRF1Tg tumours, immune and inflammatory processes were altered, with reduced tumoral infiltration of neutrophils and CD4 positive T cells, which can be explained by decreased levels of complement factor D (CFD) and C7 components of the complement cascade, an innate immune pathway that influences the adaptive immune response. We tested if the secretome was involved in BRF1-driven tumorigenesis. Unbiased proteomic analysis on BRF1-overexpresing PC3 cells confirmed reduced levels of CFD in the secretome, implicating the complement system in prostate carcinogenesis. We further identify that expression of C7 significantly correlates with expression of CD4 and has the potential to alter clinical outcome in human prostate cancer, where low levels of C7 associate with poorer prognosis.

Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology
Fulltext Coeliac disease: immunogenicity studies of barley hordein and rye secalin-derived peptides

Wahab WA, Šuligoj T, Ellis J, Côrtez-Real B, Ciclitira PJ

Int J Exp Pathol, 2016 Aug;97(4):303-309.
PMID: 27659035 DOI: 10.1111/iep.12199

Coeliac disease (CD) is an inflammatory disorder of the small intestine. It includes aberrant adaptive immunity with presentation of CD toxic gluten peptides by HLA-DQ2 or DQ8 molecules to gluten-sensitive T cells. A ω-gliadin/C-hordein peptide (QPFPQPEQPFPW) and a rye-derived secalin peptide (QPFPQPQQPIPQ) were proposed to be toxic in CD, as they yielded positive responses when assessed with peripheral blood T-cell clones derived from individuals with CD. We sought to assess the immunogenicity of the candidate peptides using gluten-sensitive T-cell lines obtained from CD small intestinal biopsies. We also sought to investigate the potential cross-reactivity of wheat gluten-sensitive T-cell lines with peptic-tryptic digested barley hordein (PTH) and rye secalin (PTS). Synthesised candidate peptides were deamidated with tissue transglutaminase (tTG). Gluten-sensitive T-cell lines were generated by culturing small intestinal biopsies from CD patients with peptic-tryptic gluten (PTG), PTH or PTS, along with autologous PBMCs for antigen presentation. The stimulation indices were determined by measuring the relative cellular proliferation via incorporation of (3) H-thymidine. The majority of T-cell lines reacted to the peptides studied. There was also cross-reactivity between wheat gluten-sensitive T-cell lines and the hordein, gliadin and secalin peptides. PTH, PTS, barley hordein and rye secalin-derived CD antigen-sensitive T-cell lines showed positive stimulation with PTG. ω-gliadin/C-hordein peptide and rye-derived peptide are immunogenic to gluten-sensitive T-cell lines and potentially present in wheat, rye and barley. Additional CD toxic peptides may be shared.

Matched MeSH terms: T-Lymphocytes/immunology
Human mesenchymal stromal cells modulate T-cell immune response via transcriptomic regulation

Vellasamy S, Tong CK, Azhar NA, Kodiappan R, Chan SC, Veerakumarasivam A, et al.

Cytotherapy, 2016 10;18(10):1270-83.
PMID: 27543068 DOI: 10.1016/j.jcyt.2016.06.017

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) have been identified as pan-immunosuppressant in various in vitro and in vivo inflammatory models. Although the immunosuppressive activity of MSCs has been explored in various contexts, the precise molecular signaling pathways that govern inhibitory functions remain poorly elucidated.
METHODS: By using a microarray-based global gene expression profiling system, this study aimed to decipher the underlying molecular pathways that may mediate the immunosuppressive activity of umbilical cord-derived MSCs (UC-MSCs) on activated T cells.
RESULTS: In the presence of UC-MSCs, the proliferation of activated T cells was suppressed in a dose-depended manner by cell-to-cell contact mode via an active cell-cycle arrest at the G0/G1 phase of the cell cycle. The microarray analysis revealed that particularly, IFNG, CXCL9, IL2, IL2RA and CCND3 genes were down-regulated, whereas IL11, VSIG4, GFA1, TIMP3 and BBC3 genes were up-regulated by UC-MSCs. The dysregulated gene clusters associated with immune-response-related ontologies, namely, lymphocyte proliferation or activation, apoptosis and cell cycle, were further analyzed.
CONCLUSIONS: Among the nine canonical pathways identified, three pathways (namely T-helper cell differentiation, cyclins and cell cycle regulation, and gap/tight junction signalling pathways) were highly enriched with these dysregulated genes. The pathways represent putative molecular pathways through which UC-MSCs elicit immunosuppressive activity toward activated T cells. This study provides a global snapshot of gene networks and pathways that contribute to the ability of UC-MSCs to suppress activated T cells.

Matched MeSH terms: T-Lymphocytes/immunology*
Fulltext Reduced CD4+ terminally differentiated effector memory T cells in moderate-severe house dust mites sensitized allergic rhinitis patients

Sani MM, Ashari NSM, Abdullah B, Wong KK, Musa KI, Mohamud R, et al.

Asian Pac J Allergy Immunol, 2019 Sep;37(3):138-146.
PMID: 29981564 DOI: 10.12932/AP-191217-0220

BACKGROUND: Terminally differentiated effector memory (TEMRA) T cells exert potent effector function after activation. The proportions of CD4+ T cell subsets especially memory cells in allergic rhinitis (AR) patients sensitized to house dust mites (HDMs) have not been extensively studied.
OBJECTIVE: This study aimed to compare the mean percentages and absolute counts of CD4+ memory T cell subsets between: (i) non-allergic controls and AR patients; (ii) mild AR patients and moderate-severe AR patients.
METHODS: Sensitization to Dermatophagoides farinae and Dermatophagoides pteronyssinus were determined in 33 non -allergic controls, 28 mild AR and 29 moderate-severe AR patients. Flow cytometry was used to determine the percentage of CD4+ na?ve (TN; CD45RA+CCR7+), central memory (TCM; CD45RA-CCR7+), effector memory (TEM; CD45RA-CCR7-) and TEMRA (CD45RA+CCR7-) T cells from the peripheral blood. The absolute counts of CD4+ T cell subsets were obtained by dual platform method from flow cytometer and hematology analyzer.
RESULTS: There were no significant differences in the mean percentages and absolute counts of CD4+ T cell subsets between non-allergic controls and AR patients sensitized to HDMs. However, there were significant reduction in the mean percentage (p=0.0307) and absolute count (p=0.0309) of CD4+ TEMRA cells in moderate-severe AR patients compared to mild AR patients sensitized to HDMs and 13/24 (54.2%) moderate-severe AR patients sensitized to HDMs had persistent symptoms.
CONCLUSION: Reduction in the mean percentage and absolute count of CD4+CD45RA+CCR7- TEMRA cells were observed in moderate-severe AR patients compared to mild AR patients in our population of AR patients sensitized to HDMs.

Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology*
Synchrotron microbeam radiotherapy evokes a different early tumor immunomodulatory response to conventional radiotherapy in EMT6.5 mammary tumors

Yang Y, Swierczak A, Ibahim M, Paiva P, Cann L, Stevenson AW, et al.

Radiother Oncol, 2019 04;133:93-99.
PMID: 30935588 DOI: 10.1016/j.radonc.2019.01.006

BACKGROUND: Synchrotron microbeam radiation therapy (MRT) is a new, evolving form of radiotherapy that has potential for clinical application. Several studies have shown in preclinical models that synchrotron MRT achieves equivalent tumor control to conventional radiotherapy (CRT) but with significantly reduced normal tissue damage.
METHODS: To explore differences between these two modalities, we assessed the immune cell infiltrate into EMT6.5 mammary tumors after CRT and MRT.
RESULTS: CRT induced marked increases in tumor-associated macrophages and neutrophils while there were no increases in these populations following MRT. In contrast, there were higher numbers of T cells in the MRT treated tumors. There were also increased levels of CCL2 by immunohistochemistry in tumors subjected to CRT, but not to MRT. Conversely, we found that MRT induced higher levels of pro-inflammatory genes in tumors than CRT.
CONCLUSION: Our data are the first to demonstrate substantial differences in macrophage, neutrophil and T cell numbers in tumors following MRT versus CRT, providing support for the concept that MRT evokes a different immunomodulatory response in tumors compared to CRT.

Matched MeSH terms: T-Lymphocytes/immunology
Fulltext DNA Vaccines Targeting Novel Cancer-Associated Antigens Frequently Expressed in Head and Neck Cancer Enhance the Efficacy of Checkpoint Inhibitor

Wang C, Zainal NS, Chai SJ, Dickie J, Gan CP, Zulaziz N, et al.

Front Immunol, 2021;12:763086.
PMID: 34733290 DOI: 10.3389/fimmu.2021.763086

HPV-independent head and neck squamous cell carcinoma (HNSCC) is a common cancer globally. The overall response rate to anti-PD1 checkpoint inhibitors (CPIs) in HNSCC is ~16%. One major factor influencing the effectiveness of CPI is the level of tumor infiltrating T cells (TILs). Converting TILlow tumors to TILhigh tumors is thus critical to improve clinical outcome. Here we describe a novel DNA vaccines to facilitate the T-cell infiltration and control tumor growth. We evaluated the expression of target antigens and their respective immunogenicity in HNSCC patients. The efficacy of DNA vaccines targeting two novel antigens were evaluated with or without CPI using a syngeneic model. Most HNSCC patients (43/44) co-expressed MAGED4B and FJX1 and their respective tetramer-specific T cells were in the range of 0.06-0.12%. In a preclinical model, antigen-specific T cells were induced by DNA vaccines and increased T cell infiltration into the tumor, but not MDSC or regulatory T cells. The vaccines inhibited tumor growth and improved the outcome alone and upon combination with anti-PD1 and resulted in tumor clearance in approximately 75% of mice. Pre-existence of MAGED4B and FJX1-reactive T cells in HNSCC patients suggests that these widely expressed antigens are highly immunogenic and could be further expanded by vaccination. The DNA vaccines targeting these antigens induced robust T cell responses and with the anti-PD1 antibody conferring excellent tumor control. This opens up an opportunity for combination immunotherapy that might benefit a wider population of HNSCC patients in an antigen-specific manner.

Matched MeSH terms: T-Lymphocytes/immunology
Fulltext Conformational IgE Epitope Mapping of Der p 2 and the Evaluations of Two Candidate Hypoallergens for Immunotherapy

Reginald K, Chew FT

Sci Rep, 2018 02 21;8(1):3391.
PMID: 29467434 DOI: 10.1038/s41598-018-21792-1

Epitope mapping of Der p 2, a clinically important dust-mite allergen is the first step in designing immunotherapy hypoallergen vaccine candidates. Twenty-one single alanine mutants of Der p 2 were generated and their secondary structure was analysed using circular dichroism spectra. Only one mutant, K96A resulted in a misfolded protein. All mutants were tested for serum IgE reactivity using serum from dust mite allergic individuals by immuno dot-blots. Mutations to five residues, N10, E25, K77, K96 and E102 consistently showed reduced IgE reactions compared to wild-type Der p 2, and therefore these residues constitute the major IgE epitopes of Der p 2. Two mutants with consistent low IgE binding, K96A and E102A, were subsequently evaluated as hypoallergen candidates. IgG antibodies raised in mice against both mutants could inhibit human IgE-binding to WT Der p 2. Both mutants had intact T-cell epitopes as they were able to stimulate peripheral blood mononuclear cell proliferation similar to WT Der p 2. However, a switch in Th1:Th2 cytokine profile was not observed. In summary, we have identified the major conformational epitopes of Der p 2, and evaluated two Der p 2 hypoallergen vaccine candidates for immunotherapy.

Matched MeSH terms: T-Lymphocytes/immunology
Humanization of chimeric anti-CD20 antibody by logical and bioinformatics approach with retention of biological activity

Khoo YL, Cheah SH, Chong H

Immunotherapy, 2017 06;9(7):567-577.
PMID: 28595518 DOI: 10.2217/imt-2017-0016

AIM: To develop a fully bioactive humanized antibody from the chimeric rituximab for potential clinical applications using a relatively simpler and faster logical and bioinformatics approach.
METHODS: From bioinformatics data, mismatched mouse amino acids in variable light and heavy chain amphipathic regions were identified and substituted with those common to human antibody framework. Appropriate synthetic DNA sequences inserted into vectors were transfected into HEK293 cells to produce the humanized antibody.
RESULTS: Humanized antibodies showed specific binding to CD20 and greater cytotoxicity to cancer WIL2-NS cell proliferation than rituximab in vitro.
CONCLUSION: A humanized version of rituximab with potential to be developed into a biobetter for treatment of B-cell disorders has been successfully generated using a logical and bioinformatics approach.

Matched MeSH terms: B-Lymphocytes/immunology*
Disparity in the percentage of CD4+ T lymphocytes and prognosis of HIV-infected intravenous drug users in Malaysia

Norazmi MN, Suarn S

Immunol Lett, 1994 Dec;43(3):177-82.
PMID: 7721330

The CD4+ T-lymphocyte absolute count (CD4ac), CD4+ T-lymphocyte percentage (CD4%) and total lymphocyte count (Løac) were assessed in HIV-seropositive intravenous drug users (IVDU) with reference to their correlation with the clinical categories A, B, and C as stipulated by the Centre of Disease Control and Prevention, USA (CDC) and with each other. It was found that while the CD4ac and Løac correlated with the clinical categories, CD4% did not. This may suggest that in our local setting, the CD4% may not necessarily be a suitable alternative marker to CD4ac as proposed by CDC. Furthermore, the CD4% of the normal subjects in this study was found to be relatively lower than the reported Caucasian levels. This may indicate that the use of the cut-off level of less than 14% as an AIDS-defining criteria may not be applicable for our HIV-seropositive IVDU. In addition, unlike the CD4ac which correlated directly with CD4% and Løac, the CD4% did not correlate with Løac. Therefore, due to the observed disparity with clinical status of patients and its possibly lower levels in our normal population, CD4% as a marker for staging HIV disease should be used with caution in our setting. Such findings may also have an impact on the use of established markers for the monitoring and classification of HIV-infected individuals in this region.

Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology*
Inhibition of lymphocyte proliferative responses to Helicobacter pylori by plastic adherent cells

Uyub AM, Anuar AK

Southeast Asian J Trop Med Public Health, 2001 Mar;32(1):88-94.
PMID: 11485102

A study was carried out on 49 H. pylori-positive and 11 H. pylori-negative patients to determine the reactivity of peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) and acid glycine extract (AGE) of H. pylori, and to identify cells responsible for imunosuppression. Based on response to PHA stimulation, cell-mediated immunity of all patients were competent. In some patients, however, response to AGE of H. pylori was suppressed by plastic adherent cells. This study provided evidence of the presence of plastic adherent suppressor cells which suppressed PBL response to AGE of H. pylori but not to PHA suggesting that immunosuppression is antigen specific. There is also an indication that immunosuppression may be species-specific as PBL devoid of plastic adherent cells only responded to stimulation by AGE of H. pylori but not that to AGE of C. jejuni.

Matched MeSH terms: Lymphocytes/immunology
Studies into the immunopathogenesis and laboratory diagnosis of dengue haemorrhagic fever

Pang T

Ann Acad Med Singap, 1987 Oct;16(4):612-6.
PMID: 2895602

Studies were carried out into the immunopathogenesis and laboratory diagnosis of dengue virus infections. Using an experimental system it was shown that cell-mediated immunity (CMI), as measured by delayed-type hypersensitivity (DTH) was induced in mice infected with dengue virus. The nature of the DTH response satisfies most criteria for a classical DTH reaction. In addition, it was also shown that infection with dengue virus causes a transient immunosuppression as measured by the immune response to other, unrelated antigens. With regard to the laboratory diagnosis of dengue infections, it was found that mosquito cells were a sensitive system for the isolation of dengue viruses and that the success of isolation was related to the antibody content of the serum. A new method for the rapid isolation of dengue viruses was also developed involving the intracerebral inoculation of mosquito larvae. By the use of this method viral antigens can be detected as early as 2-3 days after specimen inoculation. The significance of these findings in relation to the immunopathogenesis, prevention and control of disease syndromes due to dengue viruses is discussed.

Matched MeSH terms: T-Lymphocytes/immunology
Fulltext Comparative study of IgA VH 3 gene usage in healthy TST(-) and TST(+) population exposed to tuberculosis: deep sequencing analysis

Chin ST, Ignatius J, Suraiya S, Tye GJ, Sarmiento ME, Acosta A, et al.

Immunology, 2015 Feb;144(2):302-11.
PMID: 25158076 DOI: 10.1111/imm.12372

The acquired immune response against tuberculosis is commonly associated with T-cell responses with little known about the role of B cells or antibodies. There have been suggestions that B cells and humoral immunity can modulate the immune response to Mycobacterium tuberculosis. However, the mechanisms involving B-cell responses in M. tuberculosis are not fully understood, in particular the antibody gene preferences. We hypothesized that a preferential use of V genes can be seen associated with resistance to infection mainly in the IgA isotype, which is of prominent importance for infection by pathogens via the mucosal route. We studied healthy individuals with long-term exposure to tuberculosis, infected (TST(+) ) and uninfected TST(-) ) with M. tuberculosis. From a total of 22 V genes analysed, the TST(-) population preferred the VH 3-23 and Vκ1 genes. The VH 3-23 genes were subsequently subjected to 454 amplicon sequencing. The TST(-) population showed a higher frequency of the D3-10 segment compared with the D3-22 segment for the TST(+) population. The J segment usage pattern was similar for both populations with J4 segment being used the most. A preferential pairing of J4 segments to D3-3 was seen for the TST(-) population. The antibodyome difference between both populations suggests a preference for antibodies with VH 3-23, D3-3, JH 4 gene usage by the TST(-) population that could be associated with resistance to infection with M. tuberculosis.

Matched MeSH terms: B-Lymphocytes/immunology
Fulltext Epstein-Barr virus, the germinal centre and the development of Hodgkin's lymphoma

Mohamed G, Vrzalikova K, Cader FZ, Vockerodt M, Nagy E, Flodr P, et al.

J Gen Virol, 2014 Sep;95(Pt 9):1861-1869.
PMID: 24893782 DOI: 10.1099/vir.0.066712-0

The relationship between Epstein-Barr virus (EBV) and the germinal centre (GC) of the asymptomatic host remains an enigma. The occasional appearance of EBV-positive germinal centres in some patients, particularly those with a history of immunosuppression, suggests that EBV numbers in the GC are subject to immune control. The relationship, if any, between lymphoid hyperplasia with EBV-positive germinal centres and subsequent or concurrent lymphomagenesis remains to be clarified. As far as the development of EBV-associated Hodgkin's lymphoma is concerned, the suppression of virus replication, mediated by LMP1 on the one hand, and the loss of B-cell receptor signalling on the other, appears to be an important pathogenic mechanism. A further important emerging concept is that alterations in the microenvironment of the EBV-infected B-cell may be important for lymphomagenesis.

Matched MeSH terms: B-Lymphocytes/immunology

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