Phenotypic analysis of T follicular helper and T follicular regulatory cells in primary selective IgM deficiency

Selective IgM deficiency (SIgMD) is a rare immunodeficiency characterized by serum IgM below two standard of mean, and normal IgG and IgA levels. Both in human and mice with selective IgM deficiency, germinal centers cells are decreased. The development of germinal center and humoral immunity are regulated in part by follicular helper T (T_FH) and follicular regulatory T (T_FR) cells. However, the analysis of circulating T_FH (cT_FH) and T_FR (cT_FR) cells in the pathogenesis of SIgMD has not been explored. We observed lower percentage of cT_FR cells in SIgMD patients than in control group. However, we did not observe any significant difference in the percentage of cT_FH cells and their subsets between both experimental groups. When data were analyzed according to specific antibody response to pneumococcal polysaccharide, we observed a higher percentage of cT_FH cells in SIgMD patients with specific antibody deficiency than in SIgMD patients with normal specific antibody response. Our results suggest that cT_FH cells and their subsets are preserved in SIgMD patients. However, the role of lower percentage of cT_FR cells in the pathogenesis of this immunodeficiency is not clear.     

Mutation analysis in CD40 ligand deficiency leading to X-linked hypogammaglobulinemia with hyper IgM syndrome

Mutations in the gene encoding CD40 ligand have been shown to be the cause of X-linked hypogammaglobulinemia with hyper IgM (HIGM1). We have used the technique of single strand conformational polymorphism (SSCP) analysis to screen for mutations in this gene in affected boys from nineteen unrelated families. Sixteen novel mutations were identified in patients, comprising six patients with single base substitutions, two patients with single base insertions, six patients with deletions ranging from one to seven bases and two patients with large deletions at the 5′ end of the gene. These mutations were distributed throughout the gene. SSCP band shifts and/or alterations in restriction enzyme digestion sites could be used for unambiguous determination of carrier status in at-risk female relatives of most of the affected boys and, in some cases, prenatal diagnosis also can be offered. © 1996 Wiley-Liss, Inc.     

Homozygous deficiency of C4 in a child with a lupus erythematosus syndrome

A complete, selective lack of C4 was found in a girl who at 2 years of age presented with an atypical rash and low titres of antinuclear antibodies (< 1/25). Rheumatoid factors were also found. The deficiency has been followed for 5 years. Tests for Chido and Rodgers antigens on the erythrocytes were negative. A possible proneness to bacterial infections has been noted with recurrent otitis media and purulent parotitis. At the age of 5, the patient developed polyarthritis of large joints and signs of glomerulonephritis. These symptoms responded well to high-dose steroid treatment. At present, there are initial signs of sclerodactylia and some persistent exanthema and parotic swelling. IgM levels were remarkably high with 19 S IgM at about 7 g/1 and 7 S IgM at about 1.5 g/l. In the large kindred studied, lower immunochemical and functional C4 values were found in carriers of the genetical defect than in the rest of the family members. The C4 deficiency gene(s) segregated with HLA A2, Cw3, B40, BfS on the paternal, and with Aw30,-, B18, BfF¹ on the maternal side of the family.     

Shift of C3 deposition from localization in the glomerulus into the tubulo-interstitial compartment in the absence of secreted IgM in immune complex glomerulonephritis

The role of secretory IgM in protecting kidney tissue from immune complex glomerulonephritis induced by 4 mg horse spleen apoferritin and 0.05 mg lipopolysaccharide has been investigated in mutant mice in which B cells do not secrete IgM, but are capable of expressing surface IgM and IgD and secreting other Ig isotypes. Glomerular size, number of glomeruli per cross-section, glomerular cellularity and urine content of protein and creatinine was comparable in treated secreted IgM (sIgM)-deficient and wild-type mice. Assessment of urinary proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed a 30 kDa low molecular weight protein in treated sIgM-deficient animals only, reflecting dysfunction of proximal tubules. A shift of bound C3 from glomeruli to the tubulo-interstitial compartment in sIgM-deficient mice also suggests tubulo-interstitial damage. In contrast, local C3 synthesis within the kidney tissue did not differ between the two treated groups. Apoptosis physiologically present to maintain kidney cell homeostasis was increased slightly in treated wild-type mice. These results indicate that secretory IgM can protect the tubulo-interstitial compartment from immune complex-induced damage without having an effect on the glomerulus.     

Autologous mixed lymphocyte reaction in man. VIII. Deficiency of autologous mixed lymphocyte reaction in patients with selective IgA deficiency

Autologous mixed lymphocyte reaction (AMLR) between T and non-T cells was studied in 12 patients with selective IgA deficiency. Seven of 12 patients demonstrated significantly (P less than 0.05) lower AMLR when compared to simultaneously studied age and sex matched controls. In the allogeneic MLR, T cells from patients responded normally to control non-T cells; however, non-T cells from patients were poor stimulators against normal responder T cells when compared to allogeneic MLR between different normal controls. The deficient AMLR in selective IgA deficiency further supports abnormal immune regulation and might explain the increased incidence of autoimmune phenomena and autoimmune diseases associated with selective IgA deficiency.     

The expression of γΔ T cell receptor and the prevalence of primed,activated and IgA-bound T cells in Behçet's syndrome

Mucosal ulceration of the oral, and to a lesser extent genital tissues is an essential feature of Behçet''s syndrome and is associated with changes in the IgA class of immune responses. Indeed, a significant increase in the proportion of cytophilic IgA1 was found in circulating CD8 and CD4 cells (P less than 0.01), with a corresponding decrease in IgA-Fc receptors on these T cells. Furthermore, 30-40% of the cytophilic IgA1 on T cells may have been of the polymeric secretory type and the rest of the monomeric variety. IgA isotype of B cells was also significantly increased (P less than 0.001), without an overall change in circulating B cells. However, a surprising finding was the significant up-regulation of gamma delta T cell receptor in the CD8 (P less than 0.01) in the absence of a change in the proportion of alpha beta T cell receptor. The results suggest that some common microbial antigen might initiate at the mucosal surface an immune defence reaction characterized by T cells with gamma delta receptors and IgA-specific B cells. However, IgA1 bound to circulating T cells may down-regulate the central T cell function.     

alpha B crystallin expression in non-lenticular tissues and selective presence in ubiquitinated inclusion bodies in human disease.

alpha B crystallin is a lens protein which has homology with the small heat-shock proteins and is also expressed in non-lenticular tissues. Polyclonal antibodies have been raised to a synthetic peptide corresponding to residues 1-10 of alpha B crystallin. The antiserum detects a 20 kDa polypeptide on nitrocellulose replicas after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate of extracts of heart muscle known to be rich in alpha B crystallin. Staining of normal human tissues reveals immunoreactivity of lens capsular epithelium, skeletal muscle, cardiac muscle, smooth muscle, renal tubular epithelium, Schwann cells, and glial cells, as has been described by other workers. In addition, positive staining of normal thyroid epithelium, colonic epithelium, and stratified squamous epithelium was seen. Tissues known to contain ubiquitinated inclusion bodies were immunostained with the anti-alpha B-crystallin antiserum. Staining of cortical Lewy bodies, astrocytic Rosenthal fibres, and hepatic Mallory bodies was seen, but only a proportion of inclusions were positive. Neurones containing the ubiquitinated inclusions of Alzheimer's disease were only very rarely immunostained and the ubiquitinated inclusions of motor neurone disease were not detected by the antiserum. Reactive astrocytes in cerebral tissues were strongly immunostained. The results suggest that alpha B crystallin is involved in the formation of ubiquitinated inclusion bodies that have associated intermediate filaments and support previous observations on the localization of a brain-specific ubiquitin carboxy-terminal hydrolase which similarly divides ubiquitinated filamentous inclusions in the central nervous system into two main groups.     

Large granular lymphocyte expansions in patients with Felty's syndrome: analysis using anti-T cell receptor V beta-specific monoclonal antibodies.

Felty's syndrome (FS), the association of rheumatoid arthritis (RA) and idiopathic neutropenia, remains an unexplained phenomenon. HLA-DR4 is found in over 90% of cases. Patients with FS may have a T cell lymphocytosis of CD3+CD8+CD57+ large granular lymphocytes (LGL syndrome). In this study of 47 patients with FS, 19% had clear evidence for LGL expansions, while in total 42% had variable evidence for the LGL syndrome using currently available techniques. Of these T cell expansions, 76% were clonal, as demonstrated by Southern blotting and analysis with T cell receptor (TCR) beta chain constant region probes. This technique may fail to detect clonal populations in some patients. Cytofluorographic analysis using antibodies specific for TCR V beta chains identified patients with clonal LGL expansions with results comparable to those obtained with Southern blotting. No evidence for shared V beta usage among expansions from different patients was seen. The role of LGL in RA and FS is currently unclear, but this technique offers a practical and accessible means of identifying patients with LGL expansions, as a starting point for further investigation.     

Subclass composition and J-chain expression of the 'compensatory' gastrointestinal IgG cell population in selective IgA deficiency.

The subclass distribution of IgG-producing immunocytes was examined by two-colour immunohistochemistry in gastrointestinal mucosa of 14 patients with selective serum IgA deficiency providing the following biopsy material: gastric (n = 1); jejunal (n = 12); colonic (n = 1); and rectal (n = 2). All except two patients suffered from various infections, and coeliac disease was observed in six of them. Control reference data were based on biopsies from immunologically intact subjects, including histologically normal jejunal (n = 10) and large bowel (n = 10) mucosa and stomach mucosa with slight chronic gastritis (n = 8). The total mucosal population of immunoglobulin-producing cells per 500 microns gut length unit was only slightly decreased in IgA deficiency because of an increased number of IgG (30%) and especially IgM (71%) immunocytes. The IgG1 immunocyte proportion in the proximal gut (median 87%) was higher than that in the comparable controls (gastric 69%, jejunal 66%). A similar trend was seen in the distal gut (69%) compared with controls from the large bowel mucosa (55%). Conversely, IgG2 and IgG3 cell proportions were significantly decreased compared with the respective controls from the proximal gut. The same was true for IgG4, which also was significantly reduced in jejunal mucosa. Paired staining for cytoplasmic J chain and immunoglobulin isotype showed 71% positivity for jejunal IgG-producing cells in IgA deficiency, which was somewhat reduced compared with comparable controls (89%). J chain appeared to be preferentially expressed by IgG1 cells (75%), but was also found in IgG2 (70%), IgG3 (32%) and IgG4 cells (33%). IgM-producing cells showed a J-chain positivity (99%) in IgA deficiency similar to normal (100%). Our results suggested that the block in mucosal B cell differentiation to IgA expression in the proximal gut is mainly located immediately upstream to the CH alpha 1 gene, giving excessive terminal maturation of J-chain-positive IgG1 immunocytes.     

Cytokine and chemokine dysregulation in hyper-IgE syndrome.

Hyper-IgE syndrome is characterized by severe recurrent staphylococcal infections, eczema, bone abnormalities, and markedly elevated levels of immunoglobulin E (IgE). The genetic basis is not known and the central immunologic defect is largely undefined. Reduced neutrophil chemotaxis is often described, and variable T cell defects have been demonstrated in some patients. It has been hypothesized that hyper-IgE is associated with a Th1/Th2 imbalance. We wished to characterize cytokine and chemokine imbalances that might reflect the underlying disease process or reflect ongoing pathologic processes. Nine patients with hyper-IgE syndrome and six controls were studied. Radioimmunoassays, flow cytometry, and gene array analyses were performed to characterize cytokine and chemokine production. Hyper-IgE patients express more IL-12, while ENA-78, MCP-3, and eotaxin are markedly underexpressed. Underexpression of a set of chemokines could explain a number of features of hyper-IgE syndrome and may offer a new paradigm for the understanding of this disorder.     

Diagnosis of chromosome 3 duplication q23→qter,deletion p25→pter in a patient with the C (trigonocephaly) syndrome

The cells of a deceased patient previously reported to have the C (trigonocephaly) syndrome were reinvestigated because his phenotype resembled that of a patient with a duplication-deficiency of chromosome 3. This diagnosis was confirmed using fibroblasts grown from frozen cells, and his mother was shown to carry an inversion of chromosome 3 in her peripheral blood leukocytes. His findings are compared to those of another patient with the C trigonocephaly syndrome with normal chromosomes and to others from the literature. At least one other patient from the literature has a phenotype compatible with “3q duplication syndrome”.     

Role of the 2 adenine (g.11293_11294insAA) insertion polymorphism in the 3' untranslated region of the factor VII (FVII) gene: molecular characterization of a patient with severe FVII deficiency

Polymorphic variants in the gene encoding factor VII (F7) affect the plasma levels of this coagulation protein and modify the clinical phenotype of FVII deficiency in some patients. In this study we report the in vitro functional analysis of a novel polymorphic variant located in the 3' untranslated region of F7: g.11293_11294insAA. To determine whether this variant regulates FVII expression, we initially compared an expression vector containing FVII cDNA with g.11293_11294insAA with the FVII wild-type (WT) construct. The kinetics of mRNA production showed that the insertion decreases the steady-state FVII mRNA levels. To assess whether the insertion influences the phenotype of FVII-deficient patients, we evaluated its effect on the expression of FVII in a patient with severe FVII deficiency (undetectable FVII activity and antigen) carrying two additional homozygous missense variations (p.Arg277Cys and p.Arg353Gln). The two substitutions alone reduced the expression of FVII activity and antigen in vitro, but with the insertion polymorphism in our expression vector the patient's phenotype of undetectable plasma FVII was recapitulated. The insertion polymorphism in the 3' untranslated region of F7 is another modifier of FVII expression that might explain the poor genotype-phenotype correlation in some FVII-deficient patients.     

Immunohistochemical and quantitative study of interstitial and intratubular Leydig cells in normal men, cryptorchidism, and Klinefelter's syndrome.

Testicular specimens from normal men and men with cryptorchidism (CR) or Klinefelter's syndrome (KS) were taken, processed for light microscopy, and stained with the avidin-biotin peroxidase complex method for immunohistochemical detection of testosterone. The Leydig cells were classified by their morphology (normal, multivacuolated, and pleomorphic Leydig cells) and by their staining affinity for anti-testosterone antibodies (T-, T+, and T++ cells), and the average numbers of each cell type for each group of testes were calculated. Normal testes showed morphologically normal interstitial Leydig cells (96.0 +/- 10 per cent) and multivacuolated Leydig cells (4.0 +/- 1 per cent). Cryptorchid testes showed normal Leydig cells (85.8 +/- 11 per cent) and multivacuolated Leydig cells (14.2 +/- 2.3 per cent). Men with KS showed normal Leydig cells (78.9 +/- 9.1 per cent), multivacuolated Leydig cells (9.2 +/- 1.2 per cent), and pleomorphic Leydig cells (11.0 +/- 1.8 per cent). The percentage of T++ cells was higher in normal testes (29.4 +/- 2.1 per cent) than in CR (11.4 +/- 2.2 per cent) and KS testes (6.3 +/- 0.7 per cent). This suggests reduced functional Leydig cell activity in CR and KS. Multivacuolated Leydig cells showed weaker immunostaining than did normal Leydig cells in all the testicular groups. No immunostaining was shown by pleomorphic Leydig cells. Intratubular Leydig cells were only found in CR and KS. Immunostaining was weaker in intratubular Leydig cells than in interstitial Leydig cells. This suggests that intratubular location reduces functional activity of Leydig cells.     

Restricted specificity of the autoantibody response in Goodpasture''s syndrome demonstrated by two-dimensional western blotting.

The autoantigen in Goodpasture's syndrome is known to be contained within the non-collagenous (NC1) domain of type IV collagen. We have examined the specificity of autoantibodies to glomerular basement membrane (GBM) using the technique of 2-D electrophoresis followed by Western blotting. Protein stains of 2-D gels of collagenase-digested human GBM revealed extensive charge and size heterogeneity. Major components were of mol. wt 24-30 kD and 43-56 kD, corresponding to monomeric and dimeric subunits of NCl. Western blotting of 2-D gels with IgG from patients with anti-GBM disease demonstrated that the most antigenic components migrated as cationic 28-kD monomers (pI 10) and similarly charged dimers, although other components were recognized less strongly. The mobility of the strongly antigenic polypeptides was different to that of the known alpha 1 and alpha 2 chains of type IV collagen. Autoantibodies from all 20 patients studied showed the same pattern of reactivity, regardless of their clinical features (in particular, the presence or absence of pulmonary haemorrhage) or HLA type. A monoclonal antibody (P1) to human GBM bound in a similar pattern, particularly recognizing the cationic components. 2-D gels of affinity-purified GBM from a P1 column showed enrichment of the 28-kD monomers, which were recognized by human autoantibodies on Western blotting. These results demonstrate that the autoimmune response in Goodpasture's syndrome is of restricted specificity, and support the suggestion that the major autoantigenic determinant is present on the novel alpha 3 chain of type IV collagen.     

T helper type 2-like cells and therapeutic effects of interferon-γ in combined immunodeficiency with hypereosinophilia (Omenn's syndrome)

We characterized the defects of CD4+ cells in a 17-month-old girl suffering from combined immunodeficiency with hypereosinophilia (Omenn's syndrome). Because the vast majority of peripheral blood CD4⁺ cells expressed the CD45R0 isoform, we purified circulating CD4⁺ CD45R0⁺ cells from the patient and healthy individuals in order to compare their production of cytokines. The patient's CD4⁺ CD45R0⁺ cells spontaneously produced high levels of interleukin-5 (IL-5) in vitro (1600 pg/ml after 24 h of culture) and this was associated with the presence of IL-5 in serum (323 pg/ml). After stimulation with phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187, they produced higher levels of IL-4 (306 vs. 55 ± 4 pg/ml) and IL-5 (2900 vs. 213 ± 72 pg/ml) and lower levels of IL-2 (17 vs. 63 ± 17 IU/ml) and interferon-γ (IFN-γ) (16 vs. 299 ± 70 IU/ml) than controls CD4⁺ CD45R0⁺ cells. This T helper type 2 (Th2) pattern was confirmed by the detection using reverse polymerase chain reaction of IL-4, IL-5 and IL-10 mRNA within peripheral blood mononuclear cells. During a therapeutic trial with human IFN-γ (40 μg/day) which ameliorated the clinical status of the patient, we observed a down-regulation of the in vivo expression of IL-5 and IL-10, a normalization of the eosinophil count and an improvement of the Tcell response to phytohemagglutinin. This observation indicates for the first time that Th2-like cells might be involved in certain forms of congenital immunodeficiency and that IFN-γ might down-regulate their activities in vivo.     

Hermansky–Pudlak syndrome type 2: Aberrant pre‐mRNA splicing and mislocalization of granule proteins in neutrophils

Hermansky–Pudlak syndrome type 2 (HPS2) is a syndrome caused by mutations in the beta‐3A subunit of the adaptor protein (AP)‐3 complex (AP3B1 gene). We describe five unreported cases with four novel mutations, one of which caused aberrant pre‐mRNA splicing. A point mutation c.2702C>G in exon 23 of the AP3B1 gene caused deletion of 112 bp in the mRNA in two siblings. This mutation activates a cryptic donor splice site that overrules the wild‐type donor splice site of this exon. Three other novel mutations in AP3B1 were identified, that is, a nonsense mutation c.716G>A (p.Trp239Ter), a 1‐bp and a 4‐bp deletion c.177delA and c.1839_1842delTAGA, respectively, both causing frameshift and premature termination of translation. Mass spectrometry in four of these HPS2 patients demonstrated the (near) absence of all AP‐3 complex subunits. Immunoelectron microscopy on the neutrophils of two of these patients showed abnormal granule formation. We found clear mislocalization of myeloperoxidase in the neutrophils even though the content of this protein but not the activity seemed to be present at normal levels. In sum, HPS2 is the result of the absence of the entire AP‐3 complex, which results in severe neutropenia with a defect in granule formation as the major hematological finding.     

Expression of antigen reactive with a monoclonal antibody to HTLV-1 P19 in salivary glands in Sjögren''s syndrome.

To examine the possible involvement of retroviruses in Sjögren's syndrome (SS), labial salivary gland sections from 99 individuals were probed with three MoAbs to core (gag) proteins of human T cell leukaemia virus-1 (HTLV-1) and two MoAbs to HIV-1. Sections from 31% of 39 patients with primary SS (pSS) contained an epithelial cytoplasmic protein reactive with a MoAb(197) to the p19 group specific antigen (gag) of HTLV-1. The antigen was also detected in samples from 24% of 17 patients with rheumatoid arthritis (RA) and SS. 21% of 14 patients with sicca symptoms and 12.5% of 16 patients with other connective tissue diseases. It was not found in the salivary glands of 13 normal controls. A second MoAb to p19 gag, a MoAb to the p24 gag of HTLV-1 and MoAbs to HIV-1 p17and p24 gags gave negative reactions. Serum antibodies to HTLV-1 were negative, confirming that the antigen was not part of HTLV-1. The antigen showed properties consistent with an endogenous retrovirus in that it was absent in healthy tissues or resting cells but inducible by stimulation with phytohaemagglutinin (PHA) or interferon-gamma (IFN-γ) It appeared to be distinct from the endogenous retroviral sequence HRES-1. These data suggest the presence of an endogenous retrovirus in salivary gland epithelium which could contribute to the chronic inflammation of SS.