Interspecies variations in the processes of B-cell development and repertoire generation contrast with the greater consistency of T-cell development. B-cell development in mice and humans, with postnatal B-cell generation of new repertoire in the bone marrow throughout life, is regarded as the 'standard' pattern. In contrast, accounts of B cells in birds, sheep, cattle, rabbits and pigs (the 'other' species) describe cessation of gene diversification in the perinatal period, with the gut-associated lymphoid tissue (GALT) functioning as the primary lymphoid organ thereafter. It has become customary to regard the developmental pathways of T and B cells within any individual species as being as dissimilar as the functions of the two mature cell types. Reinterpretation of B-cell development patterns in different species is overdue in response to two types of reports. The first of these describe T-B 'crossover', specifically the intrathymic production of B cells and the extrathymic production of T cells. The second attests to the extent of sharing of B-cell developmental features across the two groups of species. We propose that, as is a feature of other haematopoietic cells, a menu of alternative B- and T-cell pathways has been retained and shared across species. A single pathway usually predominates in any species, masking alternatives. The observed predominance of any pathway is determined by factors such as placental permeability, extent of maturation of the immune system by birth and the feasibility of direct experimental intervention in development.
The applications of antibodies, be it monoclonal or polyclonal, in the diagnostic and research fields are well established. The disadvantage is the high cost of commercially available antibodies. In a diagnostic establishment like ours which also functions as a training ground for laboratory related personnel, it is beneficial to be able to produce in-house reagents. Therefore, we have undertaken this project to produce a rabbit polyclonal antibody against B lymphocytes. We found that the rabbit was a good choice because the titre of antibody produced was high and positive reactions were still detected at a dilution of 1:38400. The antibody showed significant positive reaction only with the lymphocyte subpopulation. A positive reaction was observed between the immunized rabbit serum and B lymphocytes but not T lymphocytes. This shows that the antibody was B lymphocyte specific. There was a positive correlation between the percentage of B lymphocytes labelled using the commercial anti-CD19 monoclonal antibody and the in-house polyclonal antibody (n = 13, r = 0.7, p = 0.02). However, the percentage of cells labelled by the in-house polyclonal anti-B was lower than that by the commercial monoclonal anti-CD19. The fluorescence intensity of the polyclonal antibody was lower than that of the monoclonal. In general, the performance of the in-house polyclonal antibody can be considered as satisfactory. The rabbit serum was stored at -20 degrees C and no significant loss of activity was detected for over a period of 19 months.
X-linked agammaglobulinemia is a rare primary immunodeficiency due to a BTK mutation. The patients are characteristically deficient in peripheral B cells and serum immunoglobulins. While they are susceptible to infections caused by bacteria, enteroviruses, and parasites, fungal infections are uncommon in XLA patients. Here, we report a boy of Malay ethnicity who suffered from recurrent upper respiratory tract infections and severe progressive necrotizing fasciitis caused by Saksenaea erythrospora. Immunological tests showed a B cell deficiency and hypogammaglobulinemia. Whole-exome sequencing identified a dinucleotide deletion (c.1580_1581del) in BTK, confirmed by Sanger sequencing and predicted to be disease causing by in silico functional prediction tools (Varsome and MutationTaster2) but was absent in the gnomAD database. This mutation resulted in a frameshift and premature termination (p.C527fs), which disrupted the protein structure. The mother was heterozygous at the mutation site, confirming her carrier status. Flow cytometric analysis of monocyte BTK expression showed it to be absent in the patient and bimodal in the mother. This study describes a novel BTK mutation in a defined hotspot and an atypical fungal phenotype in XLA. Further studies are required to understand the pathogenesis of fungal infection in XLA.
Lymphoma is generally a nodal disease and arises from lymphoid tissues or organs. Extranodal lymphoma accounts for almost a third of malignant lymphomas. Squamous cell carcinoma accounts for 90 % of laryngeal carcinoma, while extranodal Non Hodgkin Lymphoma (NHL) attributes only less than 1% of laryngeal neoplasms. Less than 100 of such cases been reported in literature since 1952. As to our best knowledge, no such case was ever reported in our country. We report a case of a 58-year-old gentleman who presented the typical history of laryngeal malignancy however the pathology turned out to be as NHLof Diffuse Large B-cell subtype.
The effect of extracts of champedak (Artocarpus integer) seed lectin on the proliferation of normal human lymphocyte was investigated. The IgA1 binding lectin was demonstrated to stimulate the proliferation of human peripheral blood mononuclear cells. Action of the lectin on enriched T and B cell populations demonstrated T lymphocyte specificity. The lectin was not mitogenic to B lymphocytes. Optimal stimulation of proliferative response was achieved when cells were subjected to 5 days exposure to the crude lectin at 20 micrograms/ml.
The effect of the mannose-binding champedak (Artocarpus integer) lectin-M on the cellular proliferation of murine lymphocytes was investigated in this study. Our data demonstrated that the lectin was the main mitogenic component in the crude extract of the champedak seeds. It stimulated the proliferation of murine T cells at an optimal concentration of 2.5 microg/ml in a 3 day culture. Lectin-M appeared to be a T-cell mitogen as it does not induce significant DNA synthesis when cultured with spleen cells from the nude mouse. In the absence of T cells, the lectin was incapable of inducing resting B cells to differentiate into immunoglobulin secreting plasma cells.
In the past two decades, Fusarium species have been increasingly recognized as serious pathogens in immunocompromised patients. The outcome of fusariosis in the context of severe persistent neutropaenia has been almost universally fatal. The treatment of fusariosis in immunocompromised patients remains a challenge and the prognosis of systemic fusariosis in this population remains poor. This report presents a case of fatal fusariosis in a 37- year-old patient who was diagnosed with precursor-B cell Acute Lymphoblastic Leukaemia (ALL).
Primary thyroid lymphoma is a relatively uncommon pathology of the thyroid gland that mainly occurs in elderly females. We describe a rare case of B-cell thyroid lymphoma in a young healthy male. It is an important diagnosis to be considered in patients presenting with a rapidly enlarging neck mass as its management is different from other differentiated thyroid carcinoma which require total thyroidectomy plus adjuvant radioactive iodine ablation. Our report emphasizes the need for clinical awareness leading to early detection, followed by early multidisciplinary management.
Cell mediated immunity is currently thought to be involved in the pathogenesis of oral mucosal lichen planus (OMLP). However, literature reveals there is no large scale data of immunohistochemistry (IHC) study on these immune cell populations. The aim of this study was to assess and compare immune cell surface identification markers CD3, CD4, CD8, CD19 and CD83 between the OMLP (n=40) and non-specific inflammatory lesions (as control group) (n=10) qualitatively and quantitatively. Kruskal-Wallis and Mann Whitney U tests have been used to make comparison between the test and control group, p values of less than 0.05 was considered to be statistically significant. T cell surface markers (CD3+, CD4+ and CD8+), B cells (CD19+) and mature dendritic cells (CD83+) showed intense immunostaining in OMLP tissues with a significantly higher expression of positive cells than in the control group (p<0.05). CD3, CD4 and CD8+ve T cells were the predominant inflammatory cell type in OMLP rather than CD19+ B cells, supporting the role of Th1 cells in the pathogenesis of OMLP. CD83+ mature dendritic cells were present in the least number and were mostly localized to areas where there were aggregates of lymphocyte. There was a positive correlation and direct relationship between T and B lymphocyte subsets whereby as one subset increased, the other follows.
Rituximab (RTX) is a monoclonal anti-CD20 antibody used to treat non-Hodgkin's lymphoma. RTX-organising pneumonia (RTX-OP) is a rare complication following treatment with RTX. We report a 49-year-old woman, with CD5-negative B-cell lymphoproliferative disorder who developed high-grade fever, dyspnoea and dry cough 3 days after the first dose of RTX. She responded poorly to antibiotics and antifungal therapy. High-resolution CT (HRCT) of the chest revealed bilateral patchy ground-glass opacities with arcade-like signs suggestive of OP. She was pulsed with intravenous methylprednisolone and RTX was discontinued. She was able to be weaned off the non-invasive ventilation (NIV) support and was discharged with maintenance prednisolone 1 mg/kg and tapered over 6 weeks. A repeated HRCT of the chest at 6 weeks showed a total resolution of OP. This highlights the early occurrence at day 3 of RTX-OP following the first dose of RTX and the complete resolution with steroid therapy.
Dengue virus infection presents a wide spectrum of manifestations including asymptomatic condition, dengue fever (DF), or severe forms, such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) in affected individuals. The early prediction of severe dengue in patients without any warning signs who may later develop severe DHF is very important to choose appropriate intensive supportive therapy since available vaccines for immunization are yet to be approved. Severe dengue responses include T and B cell activation and apoptosis, cytokine storm, hematologic disorders and complement activation. Cytokines, complement and other unidentified factors may transiently act on the endothelium and alter normal fluid barrier function of the endothelial cells and cause plasma leakage. In this review, the host factors such as activated immune and endothelial cells and their products which can be utilized as biomarkers for severe dengue disease are discussed.
The distribution of immunoregulatory cells in the peripheral blood of an individual has now been established as an important tool in helping the management of several diseases. It is necessary to set the normal ranges of these cells for the laboratory. We have undertaken in this study to establish the reference ranges for normal Malaysian adults. We found that the mean percentages of T cells, B cells, T Helper cells (CD4), T suppressor cells (CD8), NK cells and the ratio of CD4/CD8 were 70.91%, 11.38%, 38.15%, 37.76%, 17.45%, and 1.00 respectively. There was no significant difference between the sexes. In certain parameters, there was significant differences between Malay, Chinese and Indians. The Chinese and Indians were significantly different in the distribution of B cells and in the CD4/CD8 ratio. In the case of CD4 and NK cells, the Indians were different from the other two groups.
Strict precautions were taken in our methodology to exclude any monocytes from being included in the total T and B cell estimation. There is a progressive drop in the percentage of T and B cells with age, but no significant differences between the races nor between the sexes of the same age group. Aberrancies of T and B cell percentages were noted in most infections, malignancies and even malnutrition.
Hand, foot and mouth disease (HFMD), caused by enterovirus A71 (EV-A71), presents mild to severe disease, and sometimes fatal neurological and respiratory manifestations. However, reasons for the severe pathogenesis remain undefined. To investigate this, infection and viral kinetics of EV-A71 isolates from clinical disease (mild, moderate and severe) from Sarawak, Malaysia, were characterised in human rhabdomyosarcoma (RD), neuroblastoma (SH-SY5Y) and peripheral blood mononuclear cells (PBMCs). High resolution transcriptomics was used to decipher EV-A71-host interactions in PBMCs. Ingenuity analyses revealed similar pathways triggered by all EV-A71 isolates, although the extent of activation varied. Importantly, several pathways were found to be specific to the severe isolate, including triggering receptor expressed on myeloid cells 1 (TREM-1) signalling. Depletion of TREM-1 in EV-A71-infected PBMCs with peptide LP17 resulted in decreased levels of pro-inflammatory genes for the moderate and severe isolates. Mechanistically, this is the first report describing the transcriptome profiles during EV-A71 infections in primary human cells, and the potential involvement of TREM-1 in the severe disease pathogenesis, thus providing new insights for future treatment targets.
Pregnancy, a challenging physiological state, requires shuffling of conventional immune work-sets. Strategies to tolerate the semi-allogenic fetus in normal human pregnancy are multivariate with perfect modulation of the immune cells. Pregnancy is marked by B cell lymphocytopenia accompanied by reduced responsiveness to infectious agents. Besides this old age concept, plenty of research confirms that B cells have other crucial roles in pregnancy and undergo a wide range of modifications in terms of its proliferation, switching between its subtypes, variation in antibody productions, shifting the tides of cytokines as well as regulating other immune cells. B cells establish tolerant environment in pregnancy by producing protective antibodies to encounter the foreign paternal antigens. Regulatory B cells (Bregs) have adopted anti-inflammatory characteristics to sustain normal pregnancy. Moreover, the colossal physiological alterations during human pregnancy also include synchronized changes in the cross-talks between the pregnancy hormones and B cells. These aspects of pregnancy from the view point of B cell functions have so far appeared individually in discrete reports. This review finds its novelty in concisely presenting every facet of association of B cell with human pregnancy.
Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.
Autoimmunity is the assault of immune response towards self-antigens, resulting to inflammation and tissue injury. It is staged into three phases and caused by malfunction of immune tolerance. In our body, immune tolerance is synchronized by several immunosuppressor cells such as regulatory T cells and B cells as well as myeloid-derived suppressor cells, which are prominently dysregulated in autoimmunity. Hence, targeting these cell populations serve as a significant potential in the therapy of autoimmunity. Nanotechnology with its advantageous properties is shown to be a remarkable tool as drug delivery system in this field. This review focused on the development of therapeutics in autoimmune diseases utilizing various nanoparticles formulation based on two targeting approaches in autoimmunity, passive and active targeting. Lastly, this review outlined the approved present nanomedicines as well as in clinical evaluations and issues regarding the lack of translation of these nanomedicines into the market, despite the abundant of positive experimental observations.
B cells and in particular antibodies has always played second fiddle to cellular immunity in regard to tuberculosis (TB). However, recent studies has helped position humoral immunity especially antibodies back into the foray in relation to TB immunity. Therefore, the ability to correlate the natural antibody responses of infected individuals toward TB antigens would help strengthen this concept. Phage display is an intriguing approach that can be utilized to study antibody-mediated responses against a particular infection via harvesting the B cell repertoire from infected individuals. The development of disease-specific antibody libraries or immune libraries is useful to better understand antibody-mediated immune responses against specific disease antigens. This study describes the generation of an immune single-chain variable fragment (scFv) library derived from TB-infected individuals. The immune library with an estimated diversity of 109 independent clones was then applied for the identification of monoclonal antibodies against Mycobacterium tuberculosis α-crystalline as a model antigen. Biopanning of the library isolated three monoclonal antibodies with unique gene usage. This strengthens the role of antibodies in TB immunity in addition to the role played by cellular immunity. The developed library can be applied against other TB antigens and aid antibody-derived TB immunity studies in the future.