Disease relevance of Ldhb

• These observations raise the possibility that the heterogeneity in glucose metabolism and, in particular, the sole expression of LDH-B, might identify an important biological marker of glioma cells that is critical for their progression and that might afford a new target for anticancer drugs [1].
• Hybridomas secreting a monoclonal T suppressor-effector factor (TseF) were produced by fusion of a lactate dehydrogenase B (LDHB)-specific long-term T suppressor-effector (Tse) cell line with the BW5147 thymoma [2].
• In the heterozygous T lymphoma line LDHB, variants which have lost the expression of individual H-2 class I genes are spontaneously generated in vitro at a frequency of 10(-1)-10(-2) [3].

High impact information on Ldhb

• We characterized the cell types involved in the H-2-controlled suppression of T cell response to lactate dehydrogenase B (LDHB) [4].
• A cell line (HK13) in which the class I gene Kk is stably expressed (frequency of loss variants less than 10(-4) was selected from LDHB cells by fluorescence activated cell sorting [3].
• The instability of class I gene expression in LDHB cells and the transition to stable expression may represent steps of T-cell differentiation in the thymus [3].
• The hybridoma produced by the fusion of lactate dehydrogenase-B (LDH-B)-primed B10.A(2R) mouse suppressor T (Ts) cells with the BW5147 thymoma secretes two kinds of T suppressor factors (TsF), TsF-A and TsF-E [5].
• These data suggest that, in some H-2 haplotypes, the response to LDH-B and IgG2a is the result of interaction between the I-A and I-E subregions [6].

Biological context of Ldhb

• The nucleotide sequence of the mouse coding region for lactate dehydrogenase B shows 86% identity with that of the human isoenzyme, and only eight of the 139 nucleotide differences resulted in amino acid substitutions at residues 10, 13, 14, 17, 52, 132, 236 and 317 [7].
• Mouse lactate dehydrogenase-B cDNAs were isolated from cDNA libraries of macrophage (ICR strain) and thymus (F1 hybrid of C57BL/6 and CBA strains), and their nucleotide sequences determined [7].
• The cDNA and protein sequences of mouse lactate dehydrogenase B. Molecular evolution of vertebrate lactate dehydrogenase genes A (muscle), B (heart) and C (testis) [7].
• Transfection of cDNA for LDHA, but not LDHB, into EL4 cells, which expressed IMT-1 in the cytoplasm but not on the cell surface, induced the expression of IMT-1 on the cell surface [8].
• An electrophoretically detectable variant of lactate dehydrogenase-2 in Mus musculus has been found and used to locate the structural gene, Ldh-2, on chromosome 6 [9].

Anatomical context of Ldhb

• The lactate dehydrogenase-B cDNA insert of thymus clone mB188 consists of the protein-coding sequence (1002 nucleotides), the 5' (46 nucleotides) and 3' (190 nucleotides) non-coding regions, and poly(A) tail (19 nucleotides), while macrophage clone mB168 contains a partial lactate dehydrogenase cDNA insert from codon no [7].
• This is in contrast to a previous report that the LDH-B subunit was not synthesized in germ cells [10].
• Sertoli cells were further shown to exhibit comparable amounts of five tetrameric LDH isozymes formed by combination of muscle-type LDH-A and heart-type LDH-B subunits [10].
• By using an improved Cellogel electrophoretic procedure the isozyme patterns observed in the erythrocytes and leukocytes of the variant have indicated that the CAL1 is not variant of LDHA but that of LDHB, a chromosome 12 marker [11].
• In a study of 35 horse-mouse heterohybridoma cell lines, synteny in the horse was found between LDHB, PEPB and IGF1 and between NP, MPI and IDH2 [12].

Associations of Ldhb with chemical compounds

• The predicted sequence of 333 amino acids, excluding initiation methionine, was confirmed by sequencing and/or compositional analyses of a total of 103 (31%) amino acids from tryptic peptides of mouse lactate dehydrogenase-B protein [7].
• Separation of the Ia determinants used in restricting these two antigen responses was further confirmed when pretreatment of B10.S(9R) (A alpha sA beta sE beta sJk) macrophages with A.TL anti-B10.HTT (anti-A beta sE beta sJs) serum absorbed with B10.BASR1 spleen cells blocked the LDH-B response but not the MOPC-173 response [13].
• These patterns of response to urethane matched the patterns of the immune response to lactate dehydrogenase-B (LDH-B) and immunoglobulin gamma 2a (IgG2a) proteins [14].

Other interactions of Ldhb

• Two of these, ldha and ldhb, are expressed ubiquitously [15].
• Linkage tests indicated that the locus Ldr-2 determining the amounts of the LDH B subunit in mouse liver tissue is located in chromosome 6, 19 + or - 4.1 cm away from the earlier described Ldr-1 locus [16].
• Lastly, by using the A beta mutant strain, B6CH-2bm12, it was shown that the Ir gene and Ia determinants affected by this mutation had no effect on the LDH-B and MOPC-173 proliferative responses [13].
• The major histocompatibility complex-controlled immune responsiveness of mice to two unrelated antigens, lactate dehydrogenase B (LDHB) and IgG2a myeloma protein is remarkably similar (1, 2) [17].
• Mouse hybridomas generated by fusion between a lactate dehydrogenase-B (LDH-B)-specific B10.A(2R) T suppressor (Ts) cell line and the BW5147 thymoma secrete two suppressor factors, TsF-A and TsF-E [18].

References