CD4 TCRBV CDR3 analysis in prevalent SLE cases from two ethnic groups

[Influence of underlying disease and immunosuppression on the immunocompetence in inflammatory rheumatic diseases]

Patients with inflammatory rheumatic diseases have a higher risk of infections in comparison to the general population. For this patient group, in addition to cardiovascular diseases, infections play an important role with respect to morbidity and mortality. Even if it is difficult to make concrete statements with respect to individual diseases, it can be assumed that there is a lower risk of infections in inflammatory joint diseases in comparison to connective tissue diseases and vasculitides. The increased risk of infections is determined by multiple factors, whereby the underlying factors are classified into three main categories: patient-related factors (age, comorbidities, lifestyle), disease-related factors (immunological dysfunction as part of the disease pathophysiology) and drug-related factors (type and dosage of the immunosuppression and/or immunomodulation). An improved understanding of the complexity of these associations enables the optimization of treatment and disease control taking the individual risk factors into account, with the aim of a significant reduction in the risk of infections.

Relation between HLA typing and clinical presentations in Systemic Lupus Erythematosus patients in Al-Qassim region, Saudi Arabia

BACKGROUND

Systemic lupus erythematosus (SLE) is a disease with diverse clinical presentations due to interaction between genetic and environmental factors. SLE is associated worldwide with polymorphisms at various loci, including the major histocompatibility complex (MHC), although inconsistencies exist among these studies.

AIMS

This study was carried out to investigate, the association of HLA-DRB1, DRB3, DRB4, DRB5, and DQB1 alleles in SLE patients and clinical presentations at Qassim, Saudi Arabia.

METHODS

Fifty one patients with SLE-84.3% of whom had kidney involvement were studied in a case control study for HLA-DRB1, DRB3, DRB4, DRB5, and DQB1.

RESULTS

It was found that DRB3 is a protective gene among Saudi's against SLE, HLA DRB3, HLA DRB1*11 frequency was increased in patients with serositis with a p value of (0.004), (0.047) respectively, increased frequency of HLA DQB1*3 among SLE patients with skin manifestations with a p value of (0.041), the frequency of HLA DRB1*15 alleles was increased among SLE patients with nephritis with a p value of (0.029), the frequency of HLA DRB1*11 among those with hematological manifestations with a p value of (0.03) and the frequency DRB1*10 was found to be increased among SLE patients with neurological manifestations with a p value of (0.002).

CONCLUSION

In contradistinction to what have been found among other populations DRB3 is a protective gene among Saudi's against SLE. No evidence for a role of the HLA-DRB1, DRB4, DRB5, DQB1 alleles. There was an increased HLA DRB3 frequency with serositis, DQB1*3 skin manifestations, HLA DRB1*15 with nephritis, DRB1*10 with hematological manifestations and DRB1*11 with neurological manifestations.

Flow cytometric analysis of the CD4+ TCR Vβ repertoire in the peripheral blood of children with type 1 diabetes mellitus, systemic lupus erythematosus and age-matched healthy controls

BACKGROUND

Data regarding the quantitative expression of TCR Vβ subpopulations in children with autoimmune diseases provided interesting and sometimes conflicting results. The aim of the present study was to assess by comparative flow cytometric analysis the peripheral blood CD4+ TCR Vβ repertoire of children with an organ-specific autoimmune disorder, such as type 1 diabetes mellitus (T1DM), in comparison to children with a systemic autoimmune disease, such as Systemic Lupus Erythematosus (SLE) in comparison to healthy age-matched controls of the same ethnic origin. The CD4+ TCR Vβ repertoire was analysed by flow cytometry in three groups of participants: a) fifteen newly diagnosed children with T1DM (mean age: 9.2 ± 4.78 years old), b) nine newly diagnosed children with SLE, positive for ANA and anti-dsDNA, prior to treatment (mean age: 12.8 ±1.76 years old) and c) 31 healthy age-matched controls (mean age: 6.58 ± 3.65 years old), all of Hellenic origin.

RESULTS

CD4 + TCR Vβ abnormalities (± 3SD of controls) were observed mainly in SLE patients. Statistical analysis revealed that the CD4 + Vβ4 chain was significantly increased in patients with T1DM (p < 0.001), whereas CD4 + Vβ16 one was significantly increased in SLE patients (p < 0.001) compared to controls.

CONCLUSIONS

CD4 + Vβ4 and CD4 + Vβ16 chains could be possibly involved in the cascade of events precipitating the pathogenesis of T1DM and SLE in children, respectively.

T-Cell and chemokine receptor variation in South Amerindian populations

The immune response of relatively small, endogamous populations is of special interest, because they may differ from those of large, ethnically diverse, urban groups. As a contribution to this area of investigation, we tested 99 individuals from two Brazilian native populations for two T-cell receptor gene segments (TCRBV3S1 and TCRBV18) and 241 subjects from eight tribes of this ethnic group in relation to the chemokine receptor CCR5delta32 allele. Differences in TCRBV3S1 and TCRBV18 prevalences of the Amerindians in relation to European- and African-derived individuals were not marked. We confirmed the absence of the CCR5delta32 allele in most groups, its presence in the Mura and Kaingang, probably because of European gene introgression.

T-cell senescence: a culprit of immune abnormalities in chronic inflammation and persistent infection

Long-lived clonal T cells deficient in CD28 expression are commonly found in patients with inflammatory syndromes and persistent infections. Considering that CD28 loss is the most consistent immunological marker of aging, we propose that, in pathological states, CD28(null) T cells represent prematurely senescent cells resulting from persistent immune activation. These unusual lymphocytes have aberrant functions that contribute to disease-related immune abnormalities, and the degree of accumulation of CD28(null) T cells predicts the severity of clinical manifestations. We suggest that understanding of the biological properties of T cells that have reached replicative senescence will influence the future management of certain diseases. Indeed, studies on the molecular basis for the loss of CD28 are already providing information on methods to functionally rescue senescent T cells.

CD4 positive peripheral T cells from patients with systemic lupus erythematosus (SLE) are clonally expanded

T cell activation was analysed in peripheral CD4+ T cells from both systemic lupus erythematosus (SLE) patients with active and inactive disease as well as in normal healthy donors (NHD) to investigate the involvement of CD4+ T cells in the etiopathogenesis of SLE. CD4+ T cell receptor (TCR) beta-chain transcripts, containing the complementarity determining region 3 (CDR3), were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and analysed by high-resolution polyacrylamide gel electrophoresis. In addition the CDR3 of both clonally activated as well as heterogeneous Vbeta families from SLE patients were analysed at the molecular level. We observed a restricted CDR3 length polymorphism in peripheral CD4+ T cells from SLE patients compared with NHD, more pronounced in patients with high disease activity. Furthermore, in some Vbeta families single peaks in the histogram indicated nearly monoclonal T cell expansion. Sequencing of selected TCR beta-chains revealed a increased content of acidic amino acids in the CDR3 encoded by either proximal Jbeta elements or N nucleotides. We conclude that CD4+ T cells from peripheral blood of SLE patients display features of a secondary antigen driven immune response. The bias of the CDR3 towards acidic amino acids suggests the involvement of positively charged antigens.

Analysis of accumulated T cell clonotypes in patients with systemic lupus erythematosus

OBJECTIVE

To compare the accumulated T cell clonotypes in peripheral blood (PB) samples obtained at various times, and the accumulated T cell clonotypes in a PB sample and in an affected kidney, from patients with systemic lupus erythematosus (SLE).

METHODS

Peripheral blood mononuclear cells (PBMC) were obtained at 2-4 different times from each of 5 SLE patients, with or without flare-up of the disease; in addition, a biopsied kidney tissue sample was obtained from 1 of the patients. RNA was extracted from each sample and complementary DNA was prepared. Genes that encode the variable region of T cell receptor (TCR) B chains (BV) of 3 BV families, 5S1, 8, and 14, were amplified by reverse transcription-polymerase chain reaction (PCR), and the PCR products were cloned for sequencing.

RESULTS

A total of 877 cloned TCR genes was detected in the PBMC samples and the kidney sample. Oligoclonal T cell expansion was detected in 34 of the 36 PCR-amplified BV samples from PBMC (amplification of 3 BV families in 2-4 samples from 5 patients). The composition of clonally expanded T cell clonotypes was relatively stable in the patients with inactive SLE. In contrast, the composition of clonotypes in the PB changed drastically after the patient experienced the active phase of the disease. T cell clonotypes that had accumulated in the kidney appeared to be restricted and distinct from those that had accumulated in the PB of the same patient.

CONCLUSION

Different T cell clonotypes expand at different times and at different sites in patients with active SLE. The sensitizing antigens may change over the course of the disease and may be different at each site.