Development of B-lymphocyte colony-forming cells in foetal mouse tissues.

In CBA and (CBA X C57B1)F1 mice, cells forming B-lymphocyte colonies in agar culture were first detected in the 17-day foetal liver and the following day in the spleen, bone marrow and peripheral blood. Colony-forming cells were not detected in the yolk sac or foetal thymus. Adult levels of colony-forming cells were achieved within 3 days of birth. In organ cultures of 15-day foetal liver or spleen, B-lymphocyte colony-forming cells developed during a 5-day incubation period, indicating that both organs can function as bursal analogues. Foetal liver colony-forming cells were of small size and generated colonies of cells with a pattern of membrane immunoglobulin similar to colony cells generated by cells from adult animals.     

Evidence for the ontogenic precedence of suppressor T cell functions in the human neonate

The study was undertaken to elucidate some functional characteristics of T cell subsets in human cord blood. A comparison of the cellular interactions involved in the in vitro regulation of pokeweed (PWM) vs. Epstein-Barr virus (EBV)-driven B cell differentiation was done in vitro in short-term cultures of lymphocytes from newborns or adults. T cell subsets were isolated using the monoclonal antibodies OKT4⁺ and OKT8⁺. OKT4⁺ but not OKT8⁺ T lymphocytes from adults as well as neonates suppressed EBV-induced immunoglobulin (Ig) secretion of B lymphocytes from adults. This inhibition was mediated through gamma-type interferon (IFN-γ). B cells from newborns were not inhibitable by OKT4⁺ lymphocytes as a result of their insensitivity to IFN-γ. Helper activity for PWM-induced Ig secretion was exclusively contained within the OKT4⁺ population from adult T cell donors. This function was normally not detectable in any of the neonatal T cell subsets. OKT8⁺ cells from both adults and neonates suppressed PWM-induced Ig secretion, but required the collaboration with cells within the OKT4⁺ population. The suppressor activity in the PWM system was not IFN-γ-mediated. Thus, suppressor functions for EBV-vs. PWM-induced Ig synthesis were mediated through different pathways. There was no evidence of a unique suppressor system in the newborn. In the neonate, suppressor T cell activities are developed before T helper functions, a circumstance for which there is good evolutionary reason.     

Surface immunoglobulin on cultured foetal mouse thymocytes

Organ cultures of 14–15 day foetal mouse thymus were used as a source of non-neoplastic differentiating T cells, free of contaminating B cells. Viable cells obtained from such cultured thymuses were radio-iodinated and immunoglobulins (Ig) were isolated by co-precipitation from the ¹²⁵I-labelled cell-surface proteins released during 1 h of incubation at 37°. The precipitates, both reduced and unreduced, were then analysed by polyacrylamide gel electrophoresis. The unreduced material migrated in a 5% gel as a single peak with a mobility slightly faster than that of mouse IgG. After reduction, however, two peaks were obtained (in a 10% gel), one corresponding in migration to mouse light chain and the other which moved slightly faster than mouse μ chain. This pattern was identical with that previously seen for both surface Ig of normal mouse thymocytes and neoplastic T lymphoma cells. Uncultured, 15 day foetal thymocytes did not produce any detectable co-precipitated cell surface material. Ig detected in these experiments was therefore produced during in vitro culture by non-neoplastic T cells in a system free of contaminating B cells and mouse serum proteins.     

PB76: a novel surface glycoprotein preferentially expressed on mouse pre-B cells and plasma cells detected by the monoclonal antibody G-52

A monoclonal antibody (mAb) G-5-2 was isolated which binds to transformed as well as normal cells of the B lineage but not to cells of the T cell, myeloid lineages nor to fibroblasts. mAb G-5-2 reacts with pre-B and plasma cell-transformed lines, and it preferentially recognizes normal pre-B cells from fetal liver and bone marrow as well as plasma cells from spleen of mice. G-5-2⁺ fetal liver cells isolated by cell sorter express mRNA for μ heavy chain Ig gene and generate in vitro antibody-producing cells when co-cultured with lipopolysaccharide and rat thymocyte filler cells. During development the frequency and staining intensity of G-5-2⁺ cells in fetal liver from normal mice increases from 1% G-5-2⁺ cells at day 14 to～7% positive cells at day 18 of gestation. Several strains or normal mice contain comparable numbers of G-5-2⁺ cells as well as B-220⁺ and BP-1⁺ B cell precursors in the fetal liver. Mice carrying the xid mutation have 3-4-fold less G-5-2⁺ as well as B-220⁺ and BP-1⁺ cells in the fetal liver, suggesting that the effects of the xid mutation may be manifested from early stages of B cell development. Fetal liver cells from mice carrying the scid mutation were found to contain normal numbers of G-5-2⁺ as well as B-220⁺ and BP-1⁺ pre-B cells. These results indicate that differentiation from progenitors to pre-B cells in scid mice may occur normally; the scid mutation would thus appear to affect the process of rearrangement and expression of the Ig genes in the developing pre-B cells. mAb G-5-2 precipitates a 76-kDa glycoprotein from surface-radiolabeled pre-B cells and plasma cells. Taken together, these results indicate that G-5-2 mAb recognizes a novel B cell lineage-specific surface molecule called PB76 which is preferentially expressed by pre-B cells and plasma cells.     

CTLA4Ig Primed Donor Lymphocyte Infusion: A Novel Approach to Immunotherapy after Haploidentical Transplantation for Advanced Leukemia

CTLA4Ig attenuates T cell activation by co-stimulation blockade, but natural killer (NK) cells are not only resistant to CTLA4Ig, they also may demonstrate better antileukemia effect in the presence of CTLA4Ig. To explore this phenomenon we used sequential CTLA4Ig primed donor lymphocyte infusion (DLI) after post-transplant cyclophosphamide–based haploidentical transplantation. Thirty patients (CTLA4Ig-DLI group) with advanced leukemia received CTLA4Ig on day –1 and subsequently on days +7, +21, and +35, followed 12hours later by DLI of 1 to 10?×?10⁶ CD3⁺ T cells/kg containing .1 to 3.27?×?10⁶/kg CD56⁺ NK cells, with low dose cyclosporine for 60days. The incidences of acute graft-versus-host disease (GVHD), chronic GVHD and nonrelapse mortality (NRM) were 6.7%, 21%, and 4.5 %, respectively, with disease progression of 23.3% and overall survival of 79% at 18 months. Patients without disease progression had a significant early surge in CD56^dimCD16⁺NK cells with lower NKG2A expression. CTLA4Ig primed DLI was associated with an upregulation of CD86 in mature NK cells that was not witnessed with CTLA4Ig administration alone. Thus, CTLA4Ig primed DLI resulted in early proliferation of mature NK cells with cytotoxic potential enabling early institution of adoptive immunotherapy to mitigate the risk of relapse in advanced leukemia with reduced GVHD and NRM.     

Studies on the differentiation of B lymphocytes in the mouse

The capacity of CBA mouse B lymphocytes to bind polyvalent rabbit anti-mouse immunoglobulin antibody, even when this reagent is present in low concentration, was used as an index of a lymphocyte's B cell status. Various mouse tissues were held for 30 minutes at 0° with 0.2 μ/ml of ¹²⁵I-labelled anti-Ig, and smear preparations of washed cells were examined, following radioautography, for their content of B cells. The survey covered two areas of B cell differentiation, namely the spontaneous emergence of B cells in the mouse foetus, and the development of B cells in lethally irradiated mice that had received early foetal liver as a source of haematogenous stem cells.

The foetal survey suggested a multifocal origin of B cells, commencing 3 days before birth, in all major sites of erythromyelopoiesis, namely liver, spleen and bone marrow. Lymph nodes showed B cells later than did these organs, and thymus contained virtually no B cells at any stage. A rapid influx of B cells into lymph nodes took place shortly after birth. The CBA mouse is born with somewhat over 10⁵ B lymphocytes in toto, of which the majority are in liver, spleen and blood.

The irradiation-recovery study showed: (1) that B cells are, statistically, more sensitive to high dose irradiation than T cells; (2) that a B cell-free stem cell source can repopulate the B cell pool; (3) that repopulation is surprisingly slow; and (4) that numerical and functional recovery of B cells parallel each other to a reasonable degree.

The significance of the results is discussed from the viewpoints of lymphocyte differentiation and immunological tolerance.

     

Suppression of immunoglobulin production in human peripheral blood mononuclear cells by monocytes via secretion of heavy-chain ferritin

In vitro antigen stimulation of peripheral blood mononuclear cells (PBMCs) does not induce immunoglobulin (Ig) production. However, pretreatment of PBMCs with l-leucyl-l-leucine methyl ester (LLME) prior to in vitro stimulation removes the suppression of Ig production. In the present study, we attempted to identify the target cells of LLME and determine the mechanisms by which Ig production in PBMCs is suppressed. We found that CD14⁺ monocytes are involved in the suppression of Ig production in PBMCs. Furthermore, we confirmed that heavy-chain ferritin derived from CD14⁺ monocytes suppresses Ig production in PBMCs, possibly through iron sequestration.     

Correlation of T cell receptor gene rearrangements to T cell surface antigen expression and to serum immunoglobulin level in scid mice

The severe combined immunodeficient (scid) mouse which has undetectable serum immunoglobulin (Ig) contains a small number of thymic lymphocytes which express Thy-1 and IL 2 receptors (IL 2R) but not Lyt-2 or L3T4 molecules. These thymocytes did not show any rearrangement of T cell receptor (TCR) β-chain genes. Such thymocyte characteristics in the scid mouse were similar to the 15-day embryonic thymocytes in ordinary mice, indicating that the scid mouse thymocytes are arrested in the early stage of intrathymic differentiation. However, low or medium level serum Ig was occasionally found in the littermates of the scid mouse. The thymocytes of these mice showed some evidence of TCR β-chain gene rearrangement and the presence of Lyt-2⁺/L3T4⁺ cells in correlation with the serum Ig level. In the mice with some serum Ig the thymocyte cell number was increased and the proportion of IL 2R⁺ cells was decreased. Collectively, these results suggest that the rearrangement of TCR β-chain genes is associated with the expression of Lyt-2 and L3T4 molecules in intrathymic differentiation and probably with cell proliferation of the migrated lymphoid cells in the scid mouse.     

Regulation of B cell immunoglobulin secretion by functional subsets of T lymphocytes in man

Two distinct immunoregulatory T cell subsets, termed T4⁺ and T5⁺, have been defined in man by monoclonal antibodies. Prior studies have shown that the T4⁺ T cell population provided help for B cell immunoglobulin (Ig) production and was required for generation of T5⁺ cytotoxic effector cells. In the present study, the regulatory effects of the T5⁺ T cell subset on B cell Ig secretion were determined in a pokeweed mitogen-driven system. It was found that the T5⁺ subset, in contrast to the T4⁺ subset, was incapable of providing help to B cells and, more importantly, could suppress Ig secretion by B cells in the presence of T4⁺ inducer T cells. Given earlier studies demonstrating that the T5⁺ T cell subset suppressed T cell responses as well, this population appears to represent the major suppressor subset in man for T-T and T-B interactions.     

Limited development capacity of the earliest embryonic murine thymus

Previous studies have demonstrated that murine thymus separates from the pharynx during 11.5–12 days of gestation, and that the proliferation of thymic cells starts at this age. We characterized embryonic day 12 thymus in terms of the surface phenotype of the thymus cells, the function of the lobe in supporting T cell development in organ culture, and the precursor activity of the thymus cells in a mixed culture with deoxyguanosine-treated lobes. The phenotype of the major population of embryonic day 12 thymus cells was HSA⁺, CD44⁺, c-kit⁺, Thy-1^?, CD25^?, CD4^?, CD8^?, TcR^?, and Sca-1^?. In organ culture of embryonic day 12 thymus lobes, most of the lobes did not develop well and failed to generate CD4⁺CD8⁺, CD4⁺CD8^?, or CD4^?CD8⁺ cells, even when embryonic day 14 thymus cells were added. However, thymus cells on embryonic day 12 contained T cell precursors that developed into mature T cells in co-culture with deoxyguanosine-treated fetal thymic lobes. The majority of the stromal cells in deoxyguanosine-treated embryonic day 14 thymus lobes expressed the surface molecules I-A and H-2D, whereas these cells in embryonic day 12 thymus lobes were negative for these surface molecules. Thus, our findings suggest that the embryonic day 12 thymus lobe contains T cell precursors, but that the undeveloped thymic stromal cells are insufficient to support full T cell development.     

Upregulation of CD4+CD25+ T lymphocyte by adenovirus-mediated gene transfer of CTLA4Ig fusion protein in experimental autoimmune myocarditis

Objective: To explore the effects of adenovirus vector-mediated gene transfer of CTLA4Ig fusion protein on CD4⁺CD25⁺ T cells in experimental autoimmune myocarditis (EAM).

Methods: EAM was induced by porcine cardiac myosin as previously described. Adenovirus vector-mediated CTLA4Ig gene was administrated intravenously in EAM rats on days 1, 4 and 7, with EGFP as control. On day 21, myocardium histopathology was examined and CD4⁺CD25⁺ T cells were isolated. Proliferation and suppression assays were used to evaluate the suppressive capacity of CD4⁺CD25⁺ T cells in vitro. Relative mRNA level of Foxp3 and TGF-β was determined by quantitative real-time RT-PCR; expression of CTLA-4, B7-1 and B7-2 protein was compared with Western blot in CD4⁺CD25⁺ T_regs.

Results: Severe inflammatory lesions were observed in the hearts of EGFP-treated EAM rats and the untreated ones, while Ad–CMV–CTLA4Ig alleviated the myocarditis histologically. Adenovirus vector-mediated CTLA4Ig gene transfer up-regulated the proportion of CD4⁺CD25⁺ T_regs significantly. T cell proliferation was greatly inhibited in the CTLA4Ig group compared with the untreated and EGFP-treated groups in vitro. CTLA-4 and B7-2 proteins were down-regulated in the CTLA4Ig group, Foxp3 and TGF-β mRNA was up-regulated significantly by CTLA4Ig treatment.

Conclusions: Adenovirus vector-mediated CTLA4Ig gene transfer alleviated inflammation in EAM, one of the potential mechanisms is up-regulation of CD4⁺CD25⁺ T_regs.     

Analysis of immune cells draining from the abdominal cavity as a novel tool to study intestinal transplant immunobiology

During intestinal transplant (ITx) operation, intestinal lymphatics are not reconstituted. Consequently, trafficking immune cells drain freely into the abdominal cavity. Our aim was to evaluate whether leucocytes migrating from a transplanted intestine could be recovered from the abdominal draining fluid collected by a peritoneal drainage system in the early post‐ITx period, and to determine potential applications of the assessment of draining cellular populations. The cell composition of the abdominal draining fluid was analysed during the first 11 post‐ITx days. Using flow cytometry, immune cells from blood and draining fluid samples obtained the same day showed an almost complete lymphopenia in peripheral blood, whereas CD3⁺CD4⁺CD8^‐, CD3⁺CD4^‐CD8⁺ and human leucocyte antigen D‐related (HLA‐DR)⁺CD19⁺ lymphocytes were the main populations in the draining fluid. Non‐complicated recipients evolved from a mixed leucocyte pattern including granulocytes, monocytes and lymphocytes to an exclusively lymphocytic pattern along the first post‐ITx week. At days 1–2 post‐Itx, analysis by short tandem repeats fingerprinting of CD3⁺CD8⁺ sorted T cells from draining fluid indicated that 50% of cells were from graft origin, whereas by day 11 post‐ITx this proportion decreased to fewer than 1%. Our results show for the first time that the abdominal drainage fluid contains mainly immune cells trafficking from the implanted intestine, providing the opportunity to sample lymphocytes draining from the grafted organ along the post‐ITx period. Therefore, this analysis may provide information useful for understanding ITx immunobiology and eventually could also be of interest for clinical management.     

Emergence in Cx knockout mice of a diverse cytotoxic T lymphocyte repertoire that recognizes a single peptide from the immunoglobulin constant x light chain region

Allotype- or idiotype-specific CD4⁺ T cells have been reported to recognize immunoglobulin (Ig) peptides presented by class II molecules. In contrast, few data are available concerning the generation of Ig peptide-specific CD8⁺ T cells. We have therefore investigated whether T-depleted spleen cells from Ig x light chain-expressing 129/Sv mice (129x^+/+) could induce, in Cx knockout mice (129 x^?/?), the generation of Ig constant x light chain region (Cx)-specific cytotoxic T lymphocytes (CTL). The determination of TCRβ chain expressed by nine CTL clones, together with the use of a library of overlapping peptides spanning the whole Cx sequence, show that the B cells from x^+/+ mice are able to elicit in Cx knockout mice, the emergence of a diverse CTL repertoire that recognizes one single Cx peptide presented by the H-2K^b class I molecule. In addition, these data support the notion that B cells are able to process and present on their class I molecules, peptides generated from their own x light chains.     

Daily changes in foetal urine and relationships with amniotic and allantoic fluid and maternal plasma during the last two months of pregnancy in conscious, unstressed ewes with chronically implanted catheters

1. The fluid sacs and bladders of ten foetuses and the allantoic sacs of five foetuses were catheterized between 79 and 96 days gestational age and daily samples were withdrawn until lambs were born naturally at ~147 days. Maternal jugular plasma obtained daily allowed the nutritional status of each ewe to be regulated and monitored. All lambs were observed for 7 weeks, and at post-mortem no abnormalities were seen in those operated upon in utero.

2. The osmolality, [Na⁺], [K⁺], [Cl^-], [glucose], [fructose], [urea], [amino acid] and pH of all samples were measured.

3. Foetal surgery seemed to affect the actual concentrations of some solutes, but gestational trends in foetal fluid composition were unaltered.

4. Until about 7 days before birth the foetal urine osmolality, [Na⁺], [Cl^-] and [fructose] decreased, its [urea], [amino acid] and pH remained relatively constant, and from about 120 days gestational age the [K⁺] increased. During the last 7 days there was a marked increase in the osmolality and the concentrations of all these solutes, and a decrease in pH.

5. Entry of foetal urine into the fluid sacs tended to decrease the osmolality, [Na⁺], [K⁺], [Cl^-] and [glucose] of both foetal fluids and the [amino acid] of allantoic fluid, and tended to increase the [fructose] and [urea] of both fluids and the [amino acid] of amniotic fluid.

6. Changes in urine composition suggested large daily variations in the secretion of foetal antidiuretic hormone and also a rapid increase in its secretion during the last 7 days, and particularly the last 2-4 days before birth.

7. Changes in the [Na⁺]/[K⁺] ratios of foetal urine and allantoic fluid were parallel during post-operative recovery, during the course of pregnancy and immediately before birth, and this was consistent with a simultaneous action of foetal plasma corticosteroids on the foetal kidneys and chorioallantois.

8. Variations in the [fructose] of foetal urine and allantoic fluid were parallel to changes in their [Na⁺]/[K⁺] ratios and suggested an involvement of foetal corticosteroids in the regulation of the [fructose] of foetal plasma.

9. Further evidence has been presented supporting the hypothesis that maternal induced foetal hypoglycaemia effects a relative increase in the secretion of foetal corticosteroids having an action on the chorioallantois. Also, high concentrations of maternal plasma corticosteroids may decrease the permeability of the placenta to glucose.

     

Characterization of NK cells and extrathymic T cells generated in the liver of irradiated mice with a liver shield

We previously reported that c-kit⁺ stem cells which give rise to extrathymic T cells are present in the liver of adult mice. Further characterization of extrathymic T cells in the liver of adult mice is conducted here. When mice with a liver shield were lethally (9.5 Gy) irradiated, all mice survived. All tested organs showed a distribution pattern of hepatic lymphocytes on day 7. The distribution pattern in the liver was characterized by an abundance of NK (CD3^? IL-2Rβ⁺) and extrathymic T cells (CD3^int IL-2Rβ⁺) before and after irradiation. To determine their function, post-irradiation allogeneic bone marrow transplantation (BMT) was performed in mice with or without a liver shield. Allogeneic BM cells were rejected in mice with a liver shield and specific activation of CD8⁺ CD3^int IL-2Rβ⁺ cells was induced. At that time, potent cytotoxicity of liver mononuclear cells (MNC) against allogeneic thymocytes was induced. Both NK1.1⁺ and NK1.1^? subsets of CD3^int cells expanded in these mice. An in vivo elimination experiment of the subsets indicated that the NK1.1⁺ subset of CD3^int cells (i.e. NK T cells) was much more associated with the rejection of allogeneic BM cells. However, even after the elimination of NK T cells, allogeneic BM cells were rejected. In this case, granulocytes expanded in parallel with NK1.1^? subsets. Granulocytes may also be associated with the rejection of allogeneic BM cells. These results suggest that the liver is an important haematopoietic organ even in adult life.     

Flow microfluorometric analysis of mouse thymus development in vivo and in vitro

The phenotypic properties of lymphoid cells in the developing embryonic thymus were characterized using monoclonal antibodies and flow microfluorometry. CBA/J-T6/T6 thymocytes stained with antibodies directed against Thy-1.2, Lyt-1, Lyt-2 or H-2K^k were simultaneously analyzed for fluorescence intensity and forward light scatter (FLS), a cell size-related parameter. Whereas Thy-1 and Lyt-1 antigens were already present on 15-day fetal thymocytes, Lyt-2 expression was first detectable on day 16 and increased rapidly thereafter to reach adult levels by day 19. Concomitant with these phenotypic changes, rapid changes in FLS occurred during this time period. The FLS distribution of Lyt-2⁺ cells was initially homogeneously high (day 16) but became biphasic at days 17–18. Thereafter, the lower FLS subpopulation predominated. FLS changes in Lyt-2^? cells could be dissociated kinetically from changes in the Lyt-2⁺ subpopulation. Thus high FLS Lyt-2^? cells were the predominant subpopulation throughout the entire fetal period and could still be detected after birth, when a population with lower FLS first appeared. The embryonic thymus developing in vivo was then compared with the 13-day embryonic thymus maintained for 14 days in an in vitro organ culture system. Based on a combination of fluorescence and FLS analysis, the organ-cultured thymus appeared to share certain phenotypic properties with the 18–19 day in vivo developing thymus.     

Unlike CD4+ T-cell help, CD28 costimulation is necessary for effective primary CD8+ T-cell influenza-specific immunity

The importance of costimulation on CD4⁺ T cells has been well documented. However, primary CTLs against many infections including influenza can be generated in the absence of CD4⁺ T‐cell help. The role of costimulation under such “helpless” circumstances is not fully elucidated. Here, we investigated such a role for CD28 using CTLA4Ig transgenic (Tg) mice. To ensure valid comparison across the genotypes, we showed that all mice had similar naïve precursor frequencies and similar peak viral loads. In the absence of help, viral clearance was significantly reduced in CTLA4Ig Tg mice compared with WT mice. CD44⁺BrdU⁺influenza‐specific CD8⁺ T cells were diminished in CTLA4Ig Tg mice at days 5 and 8 postinfection. Adoptive transfer of ovalbumin‐specific transgenic CD8⁺ T cells (OT‐I)‐I cells into WT or CTLA4Ig Tg mice revealed that loss of CD28 costimulation resulted in impairment in OT‐I cell division. As shown previously, neither viral clearance nor the generation of influenza‐specific CD8⁺ T cells was affected by the absence of CD4⁺ T cells alone. In contrast, both were markedly impaired by CD28 blockade of “helpless” CD8⁺ T cells. We suggest that direct CD28 costimulation of CD8⁺ T cells is more critical in their priming during primary influenza infection than previously appreciated.     

Suppression of Immune Parameters in Animal Models of Morphine Dependence

Implantation of pellets containing 75 mg of morphine induced short term (4 day) morphine dependence and markedly reduced total number of spleen cells of BALB/c mice, without affecting total body or liver weight. Polyclonal responses induced by anti-CD3 antibodies, Concanavalin A or Escherichia coli lipopolysaccharide in the remaining spleen cells of morphine-treated mice were also inhibited. Cytofluorimetric analysis indicated that the proportion of major functional lymphocyte populations (Ig⁺, CD3⁺, CD4⁺ and CD8⁺ lymphocytes) were not significatively changed in the spleen from morphine-dependent mice. Furthermore, expression levels of surface Ig, CD3, CD4, and CD8, were similar in spleen cells from control or morphine-treated mice. So, morphine dependence in BALB/c mice under these controlled conditions results in a specific defect in lymphoid cell number and function, with no incidence on body weight or particular lymphocyte subsets.     

Involvement of (IgG and IgM)-secreting B lymphocytes in severity of autoimmune hepatitis type 1

Autoimmune hepatitis type 1 (AIH1) is an autoimmune disease attacks the liver and characterized by periportal inflammation, elevated immunoglobulins, and autoantibodies. The central role of B lymphocyte in pathogenicity of AIH1 is unclear. Here, the effect of antibody-secreting cells activity in terms of number of plaque-forming cells (PFC) on severity of AIH1 was evaluated. The high number of PFC-(IgG and IgM) in peripheral blood of patients with AIH1 was observed and this was concomitant with increase in the number of CD4⁺ T lymphocyte, immunoglobulin (Ig) (IgG and IgM) concentrations, and levels of liver function tests (LFTs). However, the negative correlation (r < ?0.5, P < 0.05) between the numbers of PFC-(IgG and IgM) and CD8⁺ T lymphocytes was reported here. The present study showed the positive relationship between the concentrations of Ig (IgG and IgM) and levels of LFTs (r > +0.5, P < 0.05). The high expression of IL-10 mRNA was found in the tissue culture of peripheral blood lymphocytes obtained from patients with AIH1 as compared with that isolated from control group (P < 0.05). The current study proved the direct role of (IgG and IgM)-secreting cells in severity of AIH1. This was associated with CD4⁺ cell numbers and IL-10 mRNA expression, and mediated by IgG and IgM.