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J Colombani

Publications and source records attributed to J Colombani.

At least 55 records · Page 3Linked to original sources
PubMed1986

[Study of the HLA-DQ system by the complement fixation test on lymphocytes stimulated by phytohemagglutinin. Existence of HLA-DQX allele(s)].

The complement fixation microtechnique against PHA blasts has been used to study HLA-DQw1, 2, 3 specificities with sera from multiple transfused patients and/or from multiparous women. Several sera (6 or 7) have been used to define each DQ specificity. The sera have been chosen because of their reactivity with cells from HLA-DR 1, 2 or w6 donors (for DQw1), DR3 or 7 donors (for DQw2,) DR4 or 5 donors (for DQw3). Correlation coefficients between DQ and DR specificities were from 0.56 to 0.91. Correlation coefficients between sera were from 0.51 to 0.92 in each cluster of sera. The segregation of DQw1, 2, 3 specificities has been studied in 46 families with 234 children. This study showed haplotypes lacking DQw1, 2, 3 specificities. The segregation of such 11 DQX haplotypes has been observed in 38 children from 8 families; 5 children were DQX/DQX homozygotes. Up to now, no serological reagent defining the specificity (or specificities) corresponding to DQX has been found. No preferential association was observed between DQX and DR specificities. The gene frequencies observed in 170 haplotypes in these 46 families were as follows: DQw1: 0.400; DQw2: 0.252; DQw3: 0.282; DQX: 0.065. Detecting DQ specificities seems easier by CF on PHA blasts than by lymphocytotoxicity microtechnique against B lymphocytes and monocytes from pheripheral blood. This suggests that PHA blasts express larger quantities of DQ molecules than B lymphocytes and monocytes. The results confirm that complement fixation microtechnique against PHA blasts is efficient for HLA-DQw typing.

Alleles↗
PubMed1986

[HLA typing in patients with chronic adenopathies in a population at risk for AIDS].

HLA-A B and DR typing were performed in 77 patients with AIDS related complex (ARC)--69 lymphadenopathy associated syndrome and 8 thrombocytopenic purpura LAV/HTLV III related--and 21 symptom free homosexual males. A significant increase in the frequency of HLA DR5 antigen was observed in patients with ARC mainly in purpura thrombocytopenic patients. We suggest that increase of HLA DR5 antigen support the view that DR5 antigen could be one of the factors necessary at the spreading out clinical symptoms.

AIDS-Related Complex↗
PubMed1986

[HLA typing in classical and African Kaposi's disease].

HLA A, B, C, typing have been done in 39 patients with clinically and histologically documented classical Kaposi's sarcoma. Thirty three were also typed for HLA DR antigens. Twenty seven were males, 12 were females and three ethnic groups were represented: european caucasoids 41%, north african caucasoids 38.5% and negroids 20.5%. The only statistically significant abnormality is an increase of HLA DR5 frequency (60.6 vs 26. p less than 0.001 et RR = 4.2). Such an increase has been evidenced also in AIDS patients, with or without Kaposi's sarcoma and then is not discriminant between all this different types of the disease.

Adolescent↗
PubMed1985

Serological expression after sequential double transfection with purified HLA-A11 gene of mouse fibroblasts carrying human beta-2 microglobulin.

A genomic cosmid library constructed from DNA from a genotyped individual (JF = HLA-A11, Cw-, B38/A26, Cw7, B51) was screened for clones containing class I histocompatibility genes. Among these clones, one was found to carry a 4.8 kb Hind III fragment which is highly correlated with HLA-A11. This clone was used to transfect LMTK+ cultured mouse fibroblast transformants expressing human beta-2 microglobulin. The human beta-2 microglobulin heavy chain-associated determinant was positively detected by the M18 monoclonal antibody. HLA-A11 expression on these doubly transformed cells was specifically demonstrated by complement-dependent cytotoxicity with HLA-A11 + A3-specific but not with HLA-A3-specific monoclonal antibodies. Absorption studies with human alloantisera confirmed the presence on these cells of HLA-A11 determinants and of cross-reacting determinants which absorbed anti-HLA-A1 and -A3 alloantisera. The JF5-J27 transfected cell expressed both heavy and light chains of human class I histocompatibility genes.

Animals↗
PubMed1985

Evidence for a new HLA class II determinant present on cells from HLA-DR1 and/or -DR4 individuals.

Evidence for a new HLA class II specificity is presented. It is recognized by LE serum, which reacts with most DR1 and/or DR4 individuals (r = 0.86). Its frequency in the French population is 0.33. Absorption-elution experiments showed that the serum reactivity was not due to a mixture of anti-DR1 and anti-DR4 antibodies, but to a single antibody population which could be absorbed on and eluted from both DR1(+) or DR4(+) cells. LE specificity seemed to be expressed on DR but not on DQ molecules since the serum reacted with and could be absorbed by DR+,DQw- cells; it did not react with a DR-,DQw+ mutant cell, but did react with the DR+,DQw+ parental cell. The relationship between LE specificity and MC1 and Te23 specificities remains to be determined.

Adult↗
PubMed1985

[HLA and myasthenia. Subdivision in 3 categories].

Genetic susceptibility (HLA types), clinical and pathological findings, amount of acetylcholine receptor antibodies and T lymphocyte subpopulations were studied in 63 patients with Myasthenia Gravis (MG). The frequency of HLA-DR5 was increased among patients (0.50 versus 0.23 in controls, pc less than 0.01, relative risk 3.3) and that of HLA-DR3 previously described as associated with MG was slightly increased (0.31 versus 0.20 in controls). The relative frequencies of two T cell subpopulations (T4 helper and T8 suppressor/cytotoxic lymphocytes) were normal in HLA-DR5 positive patients while the ratio T4/T8 was increased in other MG patients, who were HLA-DR3 (p less than 0.005). The high rate was due to an increase in the absolute number of T4 lymphocytes (p less than 0.001). HLA-DR3 patients were mostly women with early onset of a severe form of the disease, marked by the presence of thymic follicular lymphoid hyperplasia. A third genetic susceptibility to this disease was recently described in patients treated with D-penicillamine, the antigenic frequency of HLA-Bw35, DR1 is significantly increased. These 3 types of association between HLA and myasthenia gravis can be related to three different physiopathological mechanisms: the first two are probably linked to individual immunity (inductor/suppressor disequilibrium), in the third association, the mechanism is immunopharmacological.

Adult↗
PubMed1984

Role of H-2 and non-H-2 genes in the control of blood magnesium levels.

Red blood cell (RBC) and plasma (P) magnesium levels have been determined in 372 male mice of 13 inbred and H-2 congenic strains with C3H or B10 genetic backgrounds. Several groups of individuals belonging to the same strains have been tested at various times over a 2-year period to verify the results. Time and interstrain variations are highly significant for both RBC and P Mg. Statistical analyses made either with or without corrections for the time effect show that the largest variations are due to the genetic background (P less than 10(-10) ), the effect of the H-2 complex being smaller but nevertheless highly significant (P less than 10(-4) to 10(-6) ), except for the RBC Mg of the strains with B10 background. These findings can be compared with those previously obtained in man, and they demonstrate the high heritability of blood Mg concentration and its association with the major histocompatibility complex or with closely linked genes.

Animals↗
PubMed1983

Monoclonal antibodies to HLA recognize monomorphic and polymorphic epitopes on BoLA.

Fourteen monoclonal antibodies recognizing monomorphic and polymorphic epitopes on class I and class II antigens of the human MHC have been assayed on lymphocytes of a panel of 20-150 BoLA typed bovine animals from 12 different breeds. Some monomorphic antibodies cross-reacted and others did not. Two polymorphic monoclonal antibodies in man recognize a polymorphism in cows that follows allospecificities (BoLA-w3, w9) already described. Immunoprecipitation experiments with monomorphic anti-B2m and anti-HLA-DR monoclonal antibodies have shown that these cross-reactions concern BoLA antigens. They also revealed that Ia-like antigens in cattle present the same two chain features characterized in other species.

Animals↗
PubMed1983

Evidence for beta 2-microglobulin-like and H-2-like antigenic determinants in Drosophila.

Serologic evidence for the existence of beta 2-microglobulin-, (beta 2m) like and H-2-like antigenic determinants in Drosophila are presented. Drosophila-cultured cells and larvae extract were shown to react specifically with a rabbit anti-rat beta 2m and a rabbit anti-mouse beta 2m antisera. G-200 pooled fractions from Drosophila larvae were shown to react with beta 2m-eluted and glycin-absorbed antisera, but not with beta 2m-absorbed or glycin-eluted antisera. These fractions also quantitatively inhibited the heterologous reaction between the anti-beta 2m antisera and purified human and rat beta 2m. The lack of reactivity of other rabbit antisera or normal serum with Drosophila, as well as the efficiency of absorption of anti-beta 2m reactivity by either rat or KCO% (Drosophila) cells, further supports the presence of beta 2m epitopes on Drosophila cells. Data are also presented showing that certain anti-H-2 alloantisera react with Drosophila. That this reactivity is indeed due to anti-H-2 antibodies is suggested by several lines of evidence, including the removal of cytotoxic alloantibodies and lack of reactivity by other mouse antisera and monoclonal reagents. Preliminary data suggest that the H-2-like and beta 2m-like determinants are physically associated on the cell surface of Drosophila cells. These findings have important implications on current concepts concerning the evolutionary origin and physiologic role of beta 2m and the major histocompatibility complex.

Animals↗
PubMed1982

[Relationship between red blood cell magnesium level and immune response in the mouse].

Red Blood cell (RBC) and plasma (P) Magnesium concentrations have been determined by atomic absorption spectrophotometry on male Mice belonging to various inbred strains: High and low responders and H-2 congenic. The antibody (Ab) levels have also been measured 10 days after injecting a threshold quantity of Sheep red cells. The strains with a high Ab response exhibit lower RBC Mg concentrations than those having a low response. Similar results, but less significant, are obtained for PMg. These findings confirm those previously obtained in Men. They suggest, moreover, the action of various genetic factors on this phenomenon, some of them being possibly associated with the major complex of histocompatibility.

Animals↗
PubMed1982

Serological cross-reactivity between products of separate I regions.

A B10.S(7R) anti-B10.S(9R) serum (anti-IJEkCd) contained, as expected, antibodies specific for the I-E-subregion-encoded determinant Ia.7. However, tests on recombinant haplotypes demonstrated a series of unexpected weak extrareactions which could be interpreted to be directed against antigenic determinants encoded in the I-A subregion of the H-2 complex. The same type of extrareaction was observed in eluates from I-As, I-Ek cells coated with A.TH anti-A.TL (I-As, I-Ek anti-I-Ak, I-Ek) serum. This reactivity in serum and eluates could be interpreted as cross-reactivity between products of the I-E and I-A subregions.

Animals↗
PubMed1981

[Relations between blood magnesium and the H-2 system in the mouse].

Red blood cell (RBC) and plasma (P) magnesium have been determined on 148 adult male mice of inbred, congenic strains. Among C3H congenic Mice, important and significant variations of RBC Mg levels are observed following the H-2 antigens of the strains tested, while P Mg levels exhibit generally small and nonsignificant variations. The opposite situation seems to arise among B10 strains. These observations are in good keeping with the previously demonstrated relationship between HLA antigens and RBC Mg in man. They suggest, furthermore, that the association between RBC Mg and the major histocompatibility complex may be expressed or not, according to other genetic factors, independent of the major complex.

Animals↗