Cross-linking of a sequential epitope within the β-chain of HLA-DR/DP molecules suppressing B lymphocyte growth and inducing homotypic cell aggregation

Abstract Cellular immunity was investigated in 43 patients with multiple myeloma (MM) by assessing 3HTdR uptake induced by monocyte-dependent [CD3 monoclonal antibodies (MoAbs), phytohemagglutinin (PHA)] and monocyte- independent (CD2 MoAbs, ionomycin + phorbolester) stimulations. The former were evaluated in peripheral blood mononuclear cells (PBMNC) and purified T cells; the latter were evaluated in purified T-cell preparations only. MM showed significantly lower PBMNC responses to PHA (P less than .001), soluble OKT3 (CD3) (P = .01), and immobilized OKT3 MoAbs (P = .01). On purification of T cells, MM responses were still defective to soluble T11(2) + T11(3) (CD2) MoAbs (P = .004), phorbol myristate acetate (PMA) plus ionomycin (P less than .001), but significantly higher to plastic-immobilized OKT3 (P = .004). In some MM, 3HTdR uptake, interleukin-2 (IL-2) receptor (CD25) expression, and IL-2 production were as high on stimulation with plastic-immobilized OKT3 as that observed in normal subjects under optimal conditions (ie, plastic-immobilized OKT3 plus accessory signals). CD3 hyperreactivity correlated with the number of CD8+ HLA-DR+ cells in MM T-cell preparations. MM patients with more than 10% CD8+ HLA-DR+ cells had significantly higher responses to immobilized OKT3 (P less than .001), but lower responses to T11(2) plus T11(3) (P = .01), and PMA plus ionomycin (P = .03) than patients with less than 10% CD8+ HLA-DR+ cells. Phenotyping of CD45RA (naive) and CD45R0 (memory) expressions in resting MM T cells showed a lower ratio of CD45RA to CD45R0 in both CD4 (P less than .05) and CD8 (P less than .001) subpopulations. These data indicate that (a) some MM T cells require significantly fewer accessory signals (if any) to express the IL-2 receptor fully, secrete IL-2, and proliferate on multivalent cross-linking of the CD3/TCR complex; and (b) this peculiar state of activation is associated with high HLA-DR expression in CD8+ lymphocytes.

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Fine map of a public antibody epitope supports α-helical conformation for the H3′ segment of HLA DR β-chain

Human Immunology ◽

10.1016/0198-8859(93)90499-q ◽

1993 ◽

Vol 37 ◽

pp. 159

Keyword(s):

Helical Conformation ◽

Antibody Epitope ◽

Hla Dr ◽

Β Chain

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Association of TRAF1, TRAF2, and TRAF3 with an Epstein-Barr virus LMP1 domain important for B-lymphocyte transformation: role in NF-kappaB activation.

Molecular and Cellular Biology ◽

10.1128/mcb.16.12.7098 ◽

1996 ◽

Vol 16 (12) ◽

pp. 7098-7108 ◽

Cited By ~ 345

Author(s):

O Devergne ◽

E Hatzivassiliou ◽

K M Izumi ◽

K M Kaye ◽

M F Kleijnen ◽

...

Keyword(s):

Epstein Barr Virus ◽

B Lymphocyte ◽

Lymphocyte Transformation ◽

Dominant Negative Mutant ◽

Binding Motif ◽

Barr Virus ◽

Growth Transformation ◽

Lymphocyte Growth ◽

Epstein Barr ◽

Nf Kappab

The Epstein-Barr virus (EBV) transforming protein LMP1 appears to be a constitutively activated tumor necrosis factor receptor (TNFR) on the basis of an intrinsic ability to aggregate in the plasma membrane and an association of its cytoplasmic carboxyl terminus (CT) with TNFR-associated factors (TRAFs). We now show that in EBV-transformed B lymphocytes most of TRAF1 or TRAF3 and 5% of TRAF2 are associated with LMP1 and that most of LMP1 is associated with TRAF1 or TRAF3. TRAF1, TRAF2, and TRAF3 bind to a single site in the LMP1 CT corresponding to amino acids (aa) 199 to 214, within a domain which is important for B-lymphocyte growth transformation (aa 187 to 231). Further deletional and alanine mutagenesis analyses and comparison with TRAF binding sequences in CD40, in CD30, and in the LMP1 of other lymphycryptoviruses provide the first evidence that PXQXT/S is a core TRAF binding motif. The negative effects of point mutations in the LMP1(1-231) core TRAF binding motif on TRAF binding and NF-kappaB activation genetically link the TRAFs to LMP1(1-231)-mediated NF-kappaB activation. NF-kappaB activation by LMP1(1-231) is likely to be mediated by TRAF1/TRAF2 heteroaggregates since TRAF1 is unique among the TRAFs in coactivating NF-kappaB with LMP1(1-231), a TRAF2 dominant-negative mutant can block LMP1(1-231)-mediated NF-kappaB activation as well as TRAF1 coactivation, and 30% of TRAF2 is associated with TRAF1 in EBV-transformed B cells. TRAF3 is a negative modulator of LMP1(1-231)-mediated NF-kappaB activation. Surprisingly, TRAF1, -2, or -3 does not interact with the terminal LMP1 CT aa 333 to 386 which can independently mediate NF-kappaB activation. The constitutive association of TRAFs with LMP1 through the aa 187 to 231 domain which is important in NF-kappaB activation and primary B-lymphocyte growth transformation implicates TRAF aggregation in LMP1 signaling.

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Down-regulation of murine B lymphocyte growth: arrest of B cells in G1 underlies immunosuppression induced by an IgM antibody

Immunology Letters ◽

10.1016/0165-2478(92)90070-5 ◽

1992 ◽

Vol 33 (3) ◽

pp. 255-261 ◽

Cited By ~ 2

Author(s):

Ferenc Uher ◽

Rudolf Mihalik ◽

Maria E. Alonso ◽

János Gergely

Keyword(s):

B Cells ◽

B Lymphocyte ◽

Growth Arrest ◽

Down Regulation ◽

Igm Antibody ◽

Lymphocyte Growth

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B-Lymphocyte Typing (HLA-DR, MT, MB) Inter laboratory Reproducibility

American Journal of Clinical Pathology ◽

10.1093/ajcp/79.5.569 ◽

1983 ◽

Vol 79 (5) ◽

pp. 569-573 ◽

Cited By ~ 1

Author(s):

Gurmukh Singh ◽

Marian Griffin

Keyword(s):

B Lymphocyte ◽

Hla Dr

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Presence of a D8/17 B lymphocyte marker and HLA-DR subgroups in patients with rheumatic heart disease

Anadolu Kardiyoloji Dergisi/The Anatolian Journal of Cardiology ◽

10.5152/akd.2011.082 ◽

2011 ◽

Author(s):

Cemsit Karakurt ◽

Can Celiloglu ◽

Unsal Ozgen ◽

Elif Yesilada ◽

Saim Yologlu ◽

...

Keyword(s):

Heart Disease ◽

Rheumatic Heart Disease ◽

B Lymphocyte ◽

Hla Dr ◽

Rheumatic Heart

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HLA-DR–Mediated Signals for Hematopoiesis and Induction of Apoptosis Involve But Are Not Limited to a Nitric Oxide Pathway

Blood ◽

10.1182/blood.v90.1.217.217_217_225 ◽

1997 ◽

Vol 90 (1) ◽

pp. 217-225 ◽

Cited By ~ 2

Author(s):

Jong Wook Lee ◽

Cassandra Beckham ◽

Bryce R. Michel ◽

Henry Rosen ◽

H. Joachim Deeg

Keyword(s):

Nitric Oxide ◽

Mhc Class Ii ◽

Affect Regulation ◽

Combined Treatment ◽

Class Ii ◽

Cross Linking ◽

No Production ◽

Hla Dr ◽

Low Concentrations ◽

Induced Apoptosis

Cross-linking of major histocompatibility complex (MHC) class II antigens by anti-HLA-DR monoclonal antibody (MoAb; H81.9; IgG2a) results in inhibition of hematopoiesis in canine and human models. Inhibition of hematopoiesis is associated with apoptosis in a proportion of marrow cells. Since in murine macrophages class II cross-linking triggers nitric oxide (NO) production, and NO is thought to affect regulation of hematopoiesis, we investigated whether NO was involved in our models. In murine J774 monocytes/macrophages, MoAb H81.9 did induce NO. NO production was blocked by NG-monomethyl-L-arginine (NMMA), an inhibitor of NO synthase (NOS), and by the antioxidant N-acetylcysteine (NAC). In human and canine long-term marrow cultures (LTMCs) and in enriched marrow monocytes, however, no measurable increase in NO production was noted after H81.9 exposure. Nevertheless, NAC protected LTMCs against H81.9 induced inhibition of hematopoiesis. Therefore, we determined the effect of an exogenous NO donator, sin-1 (3-morpholinosydnonimine), on canine and human LTMCs and on apoptosis. Sin-1 at concentrations ≥100 μg/mL inhibited LTMCs and induced apoptosis; at low concentrations (1 μg/mL), however, sin-1 stimulated the generation of colony-forming unit granulocyte-macrophage. Combined treatment with sin-1 at 100 μg/mL and MoAb H81.9 resulted in profound inhibition of hematopoiesis in both canine and human LTMCs, and had an additive effect on apoptosis. At 1 μg/mL sin-1 counteracted the effect of H81.9 on hematopoiesis. The effect of sin-1 on apoptosis and hematopoiesis in LTMC was largely prevented by NAC. These results are consistent with the hypothesis that HLA-DR mediated apoptosis and inhibition of hematopoiesis involve oxidative stress. However, the biphasic response of hematopoiesis to sin-1 suggests a complex regulatory network possibly related to differences in NO sensitivity of distinct subpopulations of cells. Signals in addition to NO appear to be involved in the effect of anti-HLA-DR MoAb on hematopoiesis.

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Pre-B cells in peripheral blood of multiple myeloma patients

Blood ◽

10.1182/blood.v66.2.416.416 ◽

1985 ◽

Vol 66 (2) ◽

pp. 416-422 ◽

Cited By ~ 42

Author(s):

LM Pilarski ◽

MJ Mant ◽

BA Ruether

Keyword(s):

Multiple Myeloma ◽

B Cells ◽

Peripheral Blood ◽

B Lymphocyte ◽

Plasma Cells ◽

Peanut Agglutinin ◽

Surface Phenotype ◽

Large Pool ◽

Hla Dr ◽

B And T Lymphocytes

Abstract Although multiple myeloma is a disease of plasma cells, abnormalities have been detected in both B and T lymphocytes in peripheral blood. Although multiple myeloma patients are deficient in surface Ig (sIg)- positive B lymphocytes, analysis of lymphocytes present in blood indicates an abnormally large pool of circulating pre-B cells. These pre-B cells express BA-1, do not bear sIg, and contain cytoplasmic mu chains. High numbers of pre-B cells occur in 88% of individuals with frank myeloma and in 44% of individuals with monoclonal gammopathy of undetermined significance. Pre-B cells bearing BA-1 differ between patients in their expression of HLA-DR and receptors for peanut agglutinin (PNA). Those pre-B cells in myeloma patients are either BA- 1+ PNA- HLA-DR+ (54% of patients) or BA-1+ PNA+ HLA-DR- (30% of patients), or have a mixture of phenotypes (14% of patients). Pre-B cells of the PNA- phenotype are almost always HLA-DR+, and PNA+ pre-B cells are HLA-DR-. Within the same patient, the pre-B cell population varies by both quantitative and qualitative definitions. The number of pre-B cells may increase 460-fold and temporal shifts of surface phenotype from BA-1+ PNA- to BA-1+ PNA+ or vice versa have been detected. These observations indicate an abnormality in the B lymphocyte differentiation pathway leading to pre-B cells in the periphery that vary in number and cell surface phenotype, and that are unable to express sIg.

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